JP6444719B2 - Semiconductor circuit breaker - Google Patents

Description

  The present invention relates to a semiconductor circuit breaker.

  In Patent Document 1, a semiconductor switch unit that switches between a power supply device and a load device between a conduction state and a cutoff state, a current detection unit that detects a current flowing from the power supply device to the load device, and a current detection unit A semiconductor circuit breaker is provided that includes a shut-off processing unit that shuts off the semiconductor switch unit when it is determined that the current is equal to or greater than a predetermined current threshold.

  In Patent Document 2, the voltage across each bidirectional switch is detected, and each unidirectional semiconductor switching element is PWM open / close controlled based on the voltage across each bidirectional switch, and based on the voltage across each bidirectional switch. , Detecting an overvoltage for each bidirectional switch and generating a switch overvoltage protection signal.

  In Patent Document 3, at least one set of two semiconductor bidirectional switches configured by combining semiconductor switches is provided, and a Zener diode and a diode are provided between the gate and collector of each semiconductor switch constituting each semiconductor switch. A voltage detection circuit that detects the voltage across the semiconductor bi-directional switch, a comparison circuit that generates an ON signal when the detected value exceeds a set value, and this comparison circuit An AND circuit that receives the output signal of the semiconductor circuit and the drive signal of the semiconductor bidirectional switch, and a gate drive circuit that drives the opposing arm that forms a pair with the output signal of the AND circuit are provided corresponding to each semiconductor bidirectional switch. When the voltage across the two-way semiconductor bidirectional switch becomes higher than the set value, the semiconductor By turning on the bidirectional switch it has been described to suppress the spike voltage generated in both directions semiconductor bidirectional switch.

  Patent Document 4 discloses that a three-phase / three-phase AC direct power converter having three bidirectional switches for each of the U, V, and W phases is controlled by a three-phase circuit having an arbitrary voltage or frequency from an AC power source. The conversion output is described.

JP 2013-172603 A Japanese Patent No. 451496 JP 2001-111398 A JP 2008-86094 A

  As shown in the patent literature, the voltage at both ends of the semiconductor bidirectional switch is detected, and when the voltage at both ends of the semiconductor bidirectional switch to be turned off becomes larger than the set value, the semiconductor bidirectional switch is turned on. Therefore, it is known to perform control so as to suppress the spike voltage generated in both directions in the semiconductor bidirectional switch.

  The present invention utilizes a semiconductor bidirectional switch capable of high-speed response, measures each of the three-phase input voltage and output voltage, and performs ON / OFF processing of each bidirectional AC switch when the measured voltage is acquired. The purpose is to control the opening and closing of the semiconductor circuit breaker by setting the inrush current to zero by operating it instantaneously for each phase.

The present invention relates to a semiconductor circuit breaker including a semiconductor switch arranged on a power supply line for supplying power from a three-phase AC input side device to an output side device.
A semiconductor switch is provided with a bidirectional AC switch by three SiC-MOSFETs installed independently for each phase of the three-phase alternating current provided in each power supply line for supplying power of each phase. The switch has a current-voltage characteristic that is a no-voltage contact capable of high-speed response that is turned on at the measurement moment when the input side voltage and the output side voltage are matched, with 20 or more switches connected in parallel at a maximum current of 100A.
A measuring device for measuring the voltage on the input side and output side of each bidirectional AC switch is provided,
A control circuit that performs ON / OFF processing of each bidirectional AC switch from the open / close command signal and the voltage measurement state of each bidirectional AC switch,
When the open / close command signal is on, the control circuit turns on or off at the measured moment of each input side and output side of the three bidirectional AC switches, and the corresponding phase bidirectional AC switch when a predetermined voltage difference exists The on or off state is maintained, and the open state or the on state is formed between the power supply device and the load device from the three states of the on or off state formed in the bidirectional AC switch of each phase. A semiconductor circuit breaker is provided.

The present invention relates to a semiconductor circuit breaker including a semiconductor switch arranged on a power supply line for supplying power from a three-phase AC input side device to an output side device.
A semiconductor switch is provided with a bidirectional AC switch by three SiC-MOSFETs installed independently for each phase of the three-phase alternating current provided in each power supply line for supplying power of each phase. 20 or more switches are connected in parallel, and have a current-voltage characteristic that is a non-voltage contact capable of high-speed response that is turned on at the moment when the voltages on the input side and the output side match.
A measuring device for measuring the voltage on the input side and output side of each AC switch is provided,
A control circuit for performing ON / OFF processing of each bidirectional AC switch from the open / close command signal and the voltage measurement results on the input side and output side of each bidirectional AC switch,
When the control circuit is in the ON state between the power supply device and the load device when the open / close command signal is on, the voltages on the input side and output side of the three bidirectional AC switches may be simultaneously or with a time delay. When the voltage at the moment of coincidence is measured, the bidirectional AC switch of each phase is turned on, and the current value flowing through each bidirectional AC switch is calculated from the measured voltage difference of each phase. Provided is a semiconductor circuit breaker characterized in that when the current value exceeds a specified value by comparing the current value with a specified value, all bidirectional AC switches are turned off from the on state to form the open state from the on state. .

The present invention relates to a semiconductor circuit breaker including a semiconductor switch arranged on a power supply line for supplying power from a three-phase AC input side device to an output side device.
A semiconductor switch is provided with a bidirectional AC switch by three SiC-MOSFETs installed independently for each phase of the three-phase alternating current provided in each power supply line for supplying power of each phase. The switch has a current-voltage characteristic that is a no-voltage contact that can be turned on at the moment when the input side voltage and the output side voltage coincide with each other with 20 or more connected in parallel at a maximum current of 100A. The output side of the direction AC switch is short-circuited,
A measuring device for measuring the voltages on the three-phase AC input side and DC output side of both AC switches for each phase is provided,
With a control circuit that performs on / off processing of each bidirectional AC switch from the open / close command signal and the voltage difference measurement result,
When the control circuit is in the ON state when the open / close command signal is ON, measure the voltage on the input side of the bidirectional AC switch of each phase, select the phase with the highest voltage, and select the DC output side The voltage is measured and turned on at the moment when the highest phase voltage matches the DC output voltage. In the state where the highest phase voltage> DC output voltage is satisfied, the bidirectional AC switch of the corresponding phase is kept on. Provided is a semiconductor circuit breaker which generates a DC output side voltage and performs a positive output half-wave rectification by turning off the other two-phase bidirectional AC switch.

The present invention relates to a semiconductor circuit breaker including a semiconductor switch arranged on a power supply line for supplying power from a three-phase AC input side device to an output side device.
A semiconductor switch is provided with a bidirectional AC switch by three SiC-MOSFETs installed independently for each phase of the three-phase alternating current provided in each power supply line for supplying power of each phase. The switch has a current-voltage characteristic that is a no-voltage contact that can be turned on at the moment when the input side voltage and the output side voltage coincide with each other with 20 or more connected in parallel at a maximum current of 100A. The output side of the direction AC switch is short-circuited,
A measuring device for measuring the voltages on the three-phase AC input side and DC output side of both AC switches for each phase is provided,
It has a control circuit that performs on / off processing of each bidirectional AC switch from the open / close command signal and the voltage difference measurement result,
When the control circuit is in the on state when the open / close command signal is on, measure the voltage on the input side of the bidirectional AC switch of each phase, select the phase with the lowest voltage, and select the DC output side Measure the voltage, turn on at the moment when the lowest phase voltage matches the DC output voltage, keep the corresponding phase bi-directional AC switch on while the condition of the lowest phase voltage <DC output voltage is satisfied, etc. A two-phase bidirectional AC switch is turned off to perform negative output half-wave rectification.

  The half-invention provides a semiconductor circuit breaker that performs full-wave rectification by combining the positive output half-wave rectification and the negative output half-wave rectification described above.

The present invention relates to a semiconductor circuit breaker including a semiconductor switch arranged on a power supply line for supplying power from a three-phase AC input side device to an output side device.
A semiconductor switch is provided with a bidirectional AC switch by three SiC-MOSFETs installed independently for each phase of the three-phase alternating current provided in each power supply line for supplying power of each phase. The switch has a current-voltage characteristic that is a no-voltage contact that can be turned on at the moment when the input side voltage and the output side voltage coincide with each other with 20 or more connected in parallel at a maximum current of 100A. The output side of the direction AC switch is short-circuited,
A measuring device for measuring the voltages on the three-phase AC input side and DC output side of both AC switches for each phase is provided,
It has a control circuit that performs on / off processing of each bidirectional AC switch from the open / close command signal and the voltage difference measurement result,
Equipped with an output voltage setting circuit that sets the output voltage setting value in the control circuit,
When the control circuit is in the ON state when the open / close command signal is ON, measure the voltage on the input side of the bidirectional AC switch of each phase, select the phase with the highest voltage, and select the DC output side The voltage is measured, and the condition of the highest phase voltage> DC output voltage is satisfied, and it turns on at the moment when the DC output voltage matches the output set voltage, and it keeps on when the DC output voltage <output set voltage. Generates output-side voltage, turns off when DC output voltage> output set voltage, and turns on / off the other two-phase bidirectional AC switches under the same conditions to perform positive output half-wave rectification A semiconductor circuit breaker is provided.

The present invention relates to a semiconductor circuit breaker including a semiconductor switch arranged on a power supply line for supplying power from a three-phase AC input side device to an output side device.
The semiconductor switch has a maximum current of 100A, and is connected in parallel to 20 or more, and three SiC-MOSFETs installed independently for each phase of the three-phase alternating current provided in each power supply line that supplies the power of each phase Each bidirectional AC switch has a current-voltage characteristic that is a non-voltage contact capable of high-speed response that is turned on at the moment when the voltages on the input side and the output side match.
The output side of each bidirectional AC switch is short-circuited,
A measuring device for measuring the voltages on the three-phase AC input side and DC output side of both AC switches for each phase is provided,
It has a control circuit that performs on / off processing of each bidirectional AC switch from the open / close command signal and the voltage difference measurement result,
Equipped with an output voltage setting circuit that sets the output voltage setting value in the control circuit,
When the control circuit is in the on state when the open / close command signal is on, measure the voltage on the input side of the bidirectional AC switch of each phase, select the phase with the lowest voltage, and select the DC output side The voltage is measured, and the condition of the lowest phase voltage <DC output voltage is met, and it turns on at the moment when the DC output voltage matches the output setting voltage. Generates DC output voltage, turns off when DC output voltage> output set voltage, turns on / off other two-phase bidirectional AC switches under the same conditions, and performs negative output half-wave rectification A semiconductor circuit breaker is provided.

  The present invention provides a semiconductor circuit breaker that performs full-wave rectification by combining the above-described positive output half-wave rectification and negative output half-wave rectification.

  When the open / close command signal is on, the control circuit turns on or off at the measured moment of each input side and output side of the three bidirectional AC switches, and turns on the corresponding phase bidirectional AC switch when there is a predetermined voltage difference Or keep it off. Utilizing a semiconductor bidirectional switch capable of high-speed response, measure the input and output voltages of each of the three phases. When the measured voltage is acquired, the on / off processing of each bidirectional AC switch is instantaneous for each phase. In this way, the inrush current can be made zero to control the opening and closing of the semiconductor circuit breaker.

The typical circuit block diagram of the bidirectional | two-way AC switch which concerns on 1st Embodiment. The circuit representation figure of SiC-MOSFET applicable to the bidirectional | two-way AC switch which concerns on 1st Embodiment. Explanatory drawing of the forward direction and reverse direction current-voltage characteristic of SiC-MOSFET and Si-MOSFET applicable to the bidirectional | two-way AC switch which concerns on 1st Embodiment. 6 is a diagram illustrating an example of a forward-reverse and reverse-drain current-drain voltage characteristic of the SiC-MOSFET applicable to the bidirectional AC switch according to the first embodiment. 6 shows an example of the drain current of the SiC-MOSFET and the forward current-voltage characteristic of the body diode applicable to the bidirectional AC switch according to the first embodiment. The current-voltage characteristic example of the bidirectional | two-way AC switch which concerns on 1st Embodiment. Explanatory drawing of the rated current operation range on the current-voltage characteristic of the bidirectional | two-way AC switch which concerns on 1st Embodiment. The typical circuit block diagram of the bidirectional | two-way AC switch which concerns on 2nd Embodiment. The typical circuit block diagram of the bidirectional | two-way AC switch which concerns on 3rd Embodiment. FIG. 10 is a schematic circuit configuration diagram of a unit cell 202 _ij of a bidirectional AC switch in the bidirectional AC switch according to the third embodiment. FIG. 4 is a schematic cross-sectional structure diagram of a SiC-DIMOSFET, which is an example of a semiconductor device applicable to the bidirectional AC switch according to the embodiment. FIG. 4 is a schematic cross-sectional structure diagram of a SiC-TMOSFET, which is an example of a semiconductor device applicable to the bidirectional AC switch according to the embodiment. The figure which shows the form of Example 1 of this invention. The figure which shows the form of Example 2-1 of this invention. The figure which shows that it becomes a value equivalent to the DC voltage value obtained by half-wave rectification. The figure which shows the form of Example 2-2 of this invention. The figure which shows that it becomes a value equivalent to the DC voltage value obtained by half-wave rectification. The figure which shows that the voltage value between DC output terminals becomes a value equivalent to full wave rectification. The figure which shows the structure of a semiconductor full wave rectifier. The figure which shows the form of Example 3-1 of this invention.

  The inventors have filed a patent application for a SiC bidirectional AC switch that can be preferably used in the present invention (Japanese Patent Application No. 2014-225000). Prior to the description of the present invention, this SiC bidirectional AC switch will be described.

  According to one aspect of the present embodiment, a first SiC-MOSFET having a first gate, a first source, and a first drain, a second gate and a second short-circuited with the first gate and the first source, respectively. A cell comprising a second SiC-MOSFET having a source and a second drain, and a gate driving circuit for controlling a gate voltage applied to the first gate and the second gate that are short-circuited to each other, A bidirectional AC switch connected in series and n in parallel, wherein the rated current when energized between the switch output terminals of the bidirectional AC switch is the first when the positive voltage is applied to the first source side. Comparing the current flowing through the channel part of the 1 SiC-MOSFET and the body diode part of the first SiC-MOS EFT, the current flowing through the channel part is larger. Bidirectional AC switches configured in Kunar current range is provided. This SiC bidirectional AC switch has a maximum current of 100A and is connected in parallel to 20 or more, and is installed independently for each phase of the three-phase AC provided on each power supply line that supplies power for each phase. Bi-directional AC switches with two SiC-MOSFETs are provided, and each bidirectional AC switch has a current-voltage characteristic that is a non-voltage contact capable of high-speed response that is turned on at the moment when the voltages on the input side and output side match. Prepare.

  Embodiments will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between the thickness and the planar dimensions, the ratio of the thickness of each layer, and the like are different from the actual ones. Therefore, specific thicknesses and dimensions should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

  Further, the following embodiment exemplifies an apparatus and a method for embodying the technical idea of the SiC bidirectional AC switch invention, and the embodiment of the SiC bidirectional AC switch invention is described below. The material, shape, structure, arrangement, etc. of the component parts are not specified as follows.

In the following description, a non-voltage contact is a contact whose contact contact resistance value has a constant value regardless of the current value, and has a linearity in current-voltage characteristics at least in the vicinity of 0 V, and the positive and negative of the voltage. This refers to the characteristics without distortion at the time of switching voltage and current waveform.
[Comparative example]
In each cell of the bidirectional AC switch according to the comparative example using Si as a material, an antiparallel diode is connected to the MOSFET portion when a positive voltage is applied to the source side of a MOS field effect transistor (FET). Instead, they are connected for the purpose of flowing a current through a diode portion having a lower on-resistance with respect to the operating current.

  In each cell of the bi-directional AC switch, when an AC voltage is applied between the switch output terminals with the MOSFET gate turned on, the barrier height of the anti-parallel diode on the side on which the anti-parallel diode is forward-biased (barrier height) In the voltage region below the voltage corresponding to, current flows only through the MOSFET, and in the voltage region above it, current flows through both the MOSFET and the antiparallel diode.

  Here, a Si MOSFET generally has a high on-resistance due to a structure for ensuring a withstand voltage, and a Si antiparallel diode (or body diode) has a pn junction diffusion potential of about 1 V or less in Si, which is a narrow band gap semiconductor. Therefore, the on-resistance can be kept low, so that the two operation modes basically exist within the rated current range of the bidirectional AC AC switch.

Therefore, the linearity of the current-voltage characteristics of the Si bi-directional AC switch is broken near zero voltage, and strictly speaking, there are characteristics and restrictions other than the contact switch characteristics. It can not be said. In addition, since the antiparallel diode is connected for the purpose of low resistance, the number of elements increases, leading to an increase in the size and cost of the entire system.
[First embodiment]
A schematic circuit configuration of the bidirectional AC switch 100 according to the first embodiment is expressed as shown in FIG.

As shown in FIG. 1, the bidirectional AC switch 100 according to the first embodiment includes first gates G1 _ij (i = 1, 2,..., M, j = 1, 2,..., N, m and n are integers of 1 or more), a first SiC-MOSFET Q1 _ij having a first source S1 _ij and a first drain D1 _ij, and a second gate short-circuited to the first gate G1 _ij and the first source S1 _ij , respectively. A gate for applying a gate voltage to the second SiC-MOSFET Q2 _ij having G2 _ij and the second source S2 _ij and having the second drain D2 _ij and the first gate G1 _ij and the second gate G2 _ij short-circuited to each other A cell 110 _{ij including} a drive circuit 13 _ij is connected in m series × n parallel.

Here, the rated current during energization between the respective drains _D1 ij · _{D2 ij} is connected switch output terminal of the 1SiC-MOSFET _{Q1 ij} and the SIC-MOSFET _{Q2 ij} is the source of the 1SiC-MOSFET _{Q1 ij} S1 _{When a} positive voltage is applied to the _ij side, the MOS current I _MOS flowing through the channel portion of the first SiC-MOSFET Q1 _ij and the BD current IBD flowing through the body diode (BD1 _ij ) portion of the first SiC-MOSEFT Q1 _ij are compared. The MOS current I _MOS flowing through the channel portion side is set within a current range that becomes larger. Here, the rated current will be described later with reference to FIG.

In the cell 110 _ij constituting the bidirectional AC switch 100 according to the first embodiment, the gate drive circuit 13 _ij operates the voltage applied between the input terminals 18A and 18B as shown in FIG. , A light emitting diode (LED) 8 _ij that can be controlled on and off. The gates G1 _ij and G2 _ij of the first SiC-MOSFET Q1 _ij and the second SiC-MOSFET Q2 _ij which are short-circuited with each other are connected to the light receiving element capable of receiving light from the light emitting diode (LED) 8 _ij and the light receiving element. A photoelectric conversion circuit including at least a charge / discharge circuit may be connected, but the illustration is omitted. That is, in the cell 110 _ij constituting the bidirectional AC switch 100 according to the embodiment, if the light emitting diode (LED) 8 _ij is continuously operated and the operation is stopped, the operation of the cell 110 _ij is also stopped. In FIG. 1, the gate control unit of the cell 110 _ij simply shows a short circuit between G1 _ij and G2 _ij .

In the cell _{110 ij} constituting a bidirectional AC switch 100 according to the first embodiment, and are connected to each other a second source _{S2 ij} of the first source _{S1 ij} and SiC-MOSFET _{Q2 ij} of SiC-MOSFET _{Q1 ij} In this way, a contact rated AC (700 × m) V / (5 is connected to a SiC-MOSFET Q1 _ij and Q2 _ij of 1200 V 80 mΩ and gate control is performed by a light receiving element that receives an optical signal from the LED 8 _ij and a charge / discharge circuit. Xn) A bidirectional AC switch can be configured.

A circuit representation of the SiC-MOSFET applicable to the cell 110 _ij constituting the bidirectional AC switch according to the first embodiment is expressed as shown in FIG. The circuit representation of FIG. 2 is the same for the Si-MOSFET.

As shown in FIG. 3, the explanatory diagrams of the forward and reverse current-voltage characteristics of the SiC-MOSFET and the Si-MOSFET applicable to the cell 110 _ij constituting the bidirectional AC switch according to the first embodiment. expressed.

Here, in the Si-MOSFET, the forward MOS current I _MOS (Si-MOS) generally has a high on-resistance as shown by the broken line in FIG. 3 even in the on-state. In addition, since the pn junction diffusion potential of the Si parallel diode (or body diode) is about 1 V or less in Si, which is a narrow band gap semiconductor, the reverse direction characteristic is, for example, up to about 0.6 V. according I _{MOS (Si-MOS)} characteristics, further about 0.6V or more reverse voltage is applied, are superimposed forward current of the body diode BD, as shown in broken line in FIG. _{3, I BD} ( Si-MOS) characteristics can be obtained.

On the other hand, in the SiC-MOSFET, the forward MOS current I _MOS (SiC-MOS) in the on state (for example, the gate voltage V _gs = 18V) is on as shown in the solid line of FIG. Low resistance. In addition, since the pn junction diffusion potential of the SiC body diode BD is about 3 V or less in SiC which is a wide gap semiconductor, the electrical characteristics of the body diode BD are, for example, the curve (SiC-MOS) of (2) in FIG. as shown in _{I BD} of up to about 0.6V is substantially non-conductive. Therefore, for example, the reverse characteristics follow the reverse MOS current I _MOS (SiC-MOS) characteristics up to about 0.6 V, and when a reverse voltage of about 0.6 V or more is further applied, As the current increases, the forward current of the body diode BD increases and the characteristic of I _MOS + I _BD (SiC-MOS) is obtained as shown by the solid line in (1) of FIG.

An example of forward and reverse drain current-drain voltage characteristics of the SiC-MOSFET applicable to the cell 110 _ij constituting the bidirectional AC switch 100 according to the first embodiment is expressed as shown in FIG. The In FIG. 4, a broken line RA indicates an example of a rated operation range when one SiC-MOSFET is air-cooled.

In FIG. 4, the forward MOS current I _MOS is not substantially conducted at the gate voltage V _gs = 0 V, and the reverse current is a current I _BD conducted to the body diode BD. On the other hand, at the gate voltage V _gs = 18 V, the SiC-MOSFET is turned on (conductive), and the forward and reverse MOS currents I _MOS both have current-voltage characteristics with good linearity within the range of the broken line RA. Has been obtained.

In the SiC-MOSFET applicable to the cell 110 _ij constituting the bidirectional AC switch according to the first embodiment, the order of the MOS current I _MOS that conducts the channel portion of the MOSFET in the ON state of the gate voltage V _gs = 18V. An example of the directional current-voltage characteristic and an example of the forward direction-voltage characteristic of the BD current I _BD that conducts the body diode BD are expressed as shown in FIG. The broken line represents the ratio of current I _BD / (I _BD + I _MOS ) (%) flowing through the body diode BD.

In the drain current-drain voltage characteristics (150 degrees: rated junction temperature) of the SiC-MOSFET, the body diode BD does not substantially operate in the region of ± 5 A or less, and the relationship reflects the electrical characteristics of the channel portion of the SiC-MOSFET. ing. That is, as shown in FIG. 5, since the drain-source on-voltage of the SiC-MOSFET at 5A is 0.68 V, the current D flowing in the channel portion and the body diode when a positive voltage is applied to the source side. The ratio I _BD / (I _BD + I _MOS ) (%) is 0.002% or less, and current flows almost completely only in the MOSFET portion. As for this tendency, at 25 ° C., the current ratio becomes 0.001% or less, and the same effect can be obtained.

  Since SiC is a wide band gap semiconductor, the diffusion potential when a pn junction is formed is very large compared to Si. For this reason, if SiC is used as a material, when a positive voltage is applied to the source side of the MOSFET in the gate-on state, the current flowing through the body diode can be suppressed, and the current can be selectively supplied only to the MOSFET portion. In other words, the pn junction diffusion potential of SiC is about 3V, and the body diode is difficult to conduct. Therefore, a bidirectional switch circuit is formed only by SiC-MOSFET, and the operating current is limited to only the MOSFET without moving the body diode. An excellent bidirectional AC switch can be manufactured.

With the circuit configuration shown in FIG. 1, a cell 110 _ij is formed by a bidirectional AC switch 100 configured such that SiC-MOSFETs Q1 _ij and Q2 _ij are connected to their sources S1 _ij and S2 _ij. The Here, the SiC-MOSFETs Q1 _ij and Q2 _ij have built-in body diodes BD1 _ij and BD2 _ij , but the diffusion potential of the pn junction is formed from SiC which is a wide band gap semiconductor, and is as high as about 3 V. On the other hand, since the dielectric breakdown electric field is high, the thickness of the drift layer can be made thin, the carrier concentration can be set high, and the drain-source on-resistance of the SiC-MOSFETs Q1 _ij and Q2 _ij can be set low. For example, the SiC-MOSFETs Q1 _ij and Q2 _ij have a withstand voltage of 1200 V, an input capacitance of 2080 pF, and a drain-source on-resistance of about 80 mΩ can be realized.

For this reason, when a positive voltage is applied to the sources S1 _ij and S2 _{ij of} the SiC-MOSFETs Q1 _ij and Q2 _ij , the on-resistance value of the channel-side current path is set to the on-resistance of the body diode BD1 _ij and BD2 _ij- side current path. The range that can be set lower can be dramatically expanded as compared with the Si-MOSFET, and current can be preferentially passed through the channel side. Even in Si-MOSFETs, if the number of parallels is increased in a large amount, the current range that can be supplied only to the channel portion can be increased. In this case, however, a control circuit corresponding to the number of MOSFET elements and the number thereof is required. The whole system becomes large and is not realistic.

  Here, if the rated current of the bidirectional AC switch is limited to a range where the current in the channel-side current path is mainly, the current-voltage characteristic of the bidirectional AC switch is the current-voltage characteristic of the current passing through the channel portion of the SiC-MOSFET. Since the main current path does not change in the middle, a sharp inflection point of the current-voltage characteristic does not appear. Further, the SiC-MOSFET has a low on-resistance, and there is almost no voltage drop even when a current flows only in the SiC-MOSFET. The contact output resistance of the switch output section is only the on-resistance of the SiC-MOSFET, and a non-voltage contact bidirectional AC switch in which a voltage drop due to other than the contact resistance hardly occurs can be configured.

  Since the bidirectional AC switch 100 according to the first embodiment uses only the linear region characteristics of the SiC-MOSFET, a bidirectional AC switch with no voltage contact with low distortion and excellent linearity is configured. can do. Further, there is no diode other than the body diode connected in reverse parallel, and the number of parts is reduced. Therefore, the device can be manufactured in a small size and at low cost, and the reliability is improved.

  In the bidirectional AC switch 100 according to the first embodiment, as shown in FIG. 5, when a positive voltage is applied to the source side of the first SiC-MOSFET, the rated current is applied to the body of the first SiC-MOSFET Q1. The current flowing to the diode BD1 side may be set within a current range in which the current is 1% or less.

That is, if the current I _BD flowing on the body diode BD side is set to be 1% or less of the total current value combined with the current I _MOS flowing on the channel side, the current can flow substantially only in the channel portion. Therefore, a bidirectional AC switch having a low current-voltage characteristic distortion rate and excellent linearity can be configured.

  Further, in the bidirectional AC switch 100 according to the first embodiment, as shown in FIG. 5, when a rated current flows, it is applied between the drain and source when the gate of the SiC-MOSFET is turned on. The absolute value of the voltage may be set to be 1.0 V or less.

  That is, by setting the drain-source on-voltage when the gate of the SiC-MOSFET is turned on within the rated current range of the bidirectional AC switch to 1.0 V or less, the current can flow substantially only through the channel portion. Therefore, a bidirectional AC switch having a low current-voltage characteristic distortion rate and excellent linearity can be configured.

  Since the body diode of the SiC-MOSFET does not substantially operate if the forward voltage is 1.0 V or less regardless of the chip area and the amount of integration, a current can substantially flow only in the channel portion. Furthermore, in the minute voltage region of 1.0 V or less, since only the linear region part of the current-voltage characteristic of the current path passing through the channel part of the MOSFET can be used, distortion of the output current waveform due to the influence of the saturation region property is also suppressed. Thus, a bidirectional AC switch having a very excellent linearity of current-voltage characteristics can be configured.

  It is an example of the current-voltage characteristic of the unit cell which comprises the bidirectional | two-way AC switch which concerns on 1st Embodiment, Comprising: The current-voltage characteristic of the bidirectional | two-way AC switch comprised from two parallel connection circuits of 1200V80m (ohm) SiC-MOSFET Is expressed as shown in FIG. A broken line RA indicates a rated operation range of a unit cell constituting a bidirectional AC switch composed of two parallel-connected circuits of SiC-MOSFETs.

  An explanatory diagram of the rated current operating range on the current-voltage characteristics of the unit cells constituting the bidirectional AC switch according to the first embodiment is expressed as shown in FIG.

The rated current is the same in the SiC-MOSFET applied to the unit cell constituting the bidirectional AC switch according to the first embodiment and in the bidirectional AC switch in which two of these SiC-MOSFETs are connected in series. Can be defined. That is, the rated current depends on the calorific value, the thermal resistance, and the cooling method, and is defined by the maximum current value that is not _more than the rated junction temperature T _jMAX under a certain cooling condition.

The current value _ID is expressed as a rated current in terms of current-voltage characteristics in the linear range of the unit cell constituting the bidirectional AC switch according to the first embodiment shown in FIG. + In current range ΔI between I _D and -I _D, the unit cells constituting the bidirectional AC switch according to the first embodiment, the linear current - voltage characteristics thereof are shown. For example, under a constant air cooling condition, a rated current I _D = 5 A is obtained at a rated junction temperature T _jMAX = 150 ° C.

  According to the bidirectional AC switch according to the first embodiment, it is possible to realize a non-voltage contact bidirectional AC switch in which each of the constituting MOSFETs does not have an antiparallel diode different from the body diode.

  According to the bidirectional AC switch according to the first embodiment, it is possible to apply an SiC-MOSFET in which the body diode does not operate in a desired current specification range, and therefore, the linearity of the current-voltage characteristic is kept good. A sagging no-voltage contact bidirectional AC switch can be realized.

In addition, the number of series-parallel cells can take an arbitrary value of 1 or more. When a sequence is formed using this bidirectional AC switch, the design complexity can be suppressed because it is a non-voltage contact. . For example, simplification of design, shortening of the design period, and avoiding malfunction due to voltage drop of the switch unit can be realized. As an example, the setting of the series / parallel number of cells in FIG. 1 will be described. And i the number of series connections each cell tolerance when the maximum value of the applied voltage was V _MAX, the maximum voltage applied to each cell obtained by dividing the maximum applied voltage V _MAX series connection number i of cells of each cell The number i of series connection of cells is set so as not to exceed the maximum voltage. Further, as described above, in order to set the current _IBD flowing on the body diode BD side to be 1% or less of the total current value including the current _IMOS flowing on the channel side, the rated current of each cell is set. When I _D = 5A is obtained, the parallel connection number j is set by dividing the maximum current I _MAX flowing through the load 24 by the rated current I _D. For example, if the on-resistance of the SiC-MOSFET is 40 mΩ, the drain-source voltage can be kept from exceeding 1 V by suppressing the drain-source current value to 5 A or less. Assuming that the maximum current I _MAX flowing through the load 24 is 100A, a value 20 obtained by dividing the maximum current I _MAX = 100A by 5A is the number of cells connected in parallel. By doing so, a bidirectional AC switch having excellent linearity can be obtained. It is preferably employed when the number j of parallel connections is 20 or more.

  Moreover, you may further provide the disconnector by the electromagnetic switch etc. which were connected in series outside the switch output terminal of the bidirectional AC switch. In a bidirectional AC switch using a semiconductor, the physical connection between the output terminals is not broken, and it is difficult to make the leakage current completely zero. A disconnector is connected in series to the output terminal of a bi-directional AC switch using semiconductors. After the bi-directional AC switch cuts off current conduction, the voltage is turned off by the disconnector, ensuring high safety. In addition, power consumption when the bidirectional AC switch is off can be suppressed. Since the bidirectional AC switch can complete the current interruption in a short time within 1 μsec, it completely eliminates the delay of the interruption time due to the discharge phenomenon peculiar to the electromagnetic switch and the possibility of the occurrence of a huge accident current. This realizes simplification of the current allowable design of wiring and electronic equipment connected to the system.

According to the bidirectional AC switch according to the first embodiment, the voltage-current characteristic is linear, and it is a small-sized, inexpensive, long-life, high withstand voltage, large-current capacity, high-speed response and non-voltage contact bidirectional An AC switch can be provided.
[Second Embodiment]
As shown in FIG. 8, a schematic circuit configuration of the bidirectional AC switch 102 according to the second embodiment is between the first drain D1 _ij and the second drain D2 _ij of each cell 111 _ij of the bidirectional AC switch 102. And a surge killer circuit 26 _ij connected thereto.

The surge killer circuit 26 _i may include a first avalanche breakdown diode (ABD) ABD1 _ij and a second avalanche breakdown diode ABD2 _ij having cathodes connected to each other.

In the bidirectional AC switch 102 according to the second embodiment, as shown in FIG. 8, a surge killer circuit 26 _i having ABD1 _ij and ABD2 _ij facing each other is connected between the output terminals of each stage. With this configuration, for example, the bidirectional AC switch 102 with the contact rated load AC (700 × m) V / (5 × n) A can be provided. Further, the voltage applied between the drain and source of the same i-th stage SiC-MOSFETs Q1 _ij and Q2 _ij can be limited by the surge killer circuit 26 _i connected to the i-th stage.

  Although SiC-MOSFET can make the thickness of the drift layer thin and carrier concentration high by utilizing the fact that SiC, which is a material, has a high breakdown electric field, there is a risk that strong electric field strength is applied to the gate insulating film. . On the other hand, because the drift layer conditions are set not for the avalanche breakdown voltage but for the purpose of reducing the electric field concentration on the gate insulating film, the device drain-source rated voltage and the avalanche breakdown voltage are greatly different. There are many.

  Here, if a SiC Schottky barrier diode (SiC-SBD: Silicon Carbide Schottky Barrier Diode) is connected in reverse parallel to the SiC-MOSFET, the voltage is limited by the avalanche breakdown of the SiC-SBD, but the SiC-MOSFET In the case where the bidirectional AC switch is configured only by this, when an unintended huge voltage is applied, there is a risk that the applied voltage continuously exceeds the drain-source rated voltage of the device without breakdown of the avalanche.

  Here, by arranging the ABDs connected in a face-to-face manner between the output terminals of each stage of the bidirectional AC switch, the voltage applied to each cell of the bidirectional AC switch can be defined by the avalanche breakdown voltage of the ABD.

  In addition, since the intermediate point of the ABD opposite to the intermediate point of the SiC-MOSFET is not connected, the influence of the forward characteristic of the ABD on the current-voltage characteristic of the bidirectional AC switch can be eliminated. The forward characteristics can be removed from the device selection criteria, and the degree of design freedom is improved.

  According to the bidirectional AC switch according to the second embodiment, the voltage applied to each cell of the bidirectional AC switch can be defined by the avalanche breakdown voltage of the ABD, has excellent linearity of voltage-current characteristics, and is compact. Low voltage, long life, high withstand voltage, large current capacity, high speed response, non-voltage contact bidirectional AC switch with reduced risk of SiC-MOSFET breakdown due to large voltage and non-uniform voltage balance can do.

  One or more surge suppressor circuits may be connected to each stage of the bidirectional switch, or may be connected to each cell. Further, the number of ABDs in series may be increased for the purpose of securing the ABD withstand voltage.

In addition, the series / parallel number of cells may take an arbitrary value of 1 or more. When a sequence is formed using this bidirectional AC switch, since it is a non-voltage contact, design complexity can be suppressed. it can. For example, it is possible to simplify the design, shorten the design period, and avoid malfunction due to the voltage drop of the switch unit.
[Third embodiment]
A schematic circuit configuration of the bidirectional AC switch 104 according to the third embodiment is expressed as shown in FIG. 9, and a schematic circuit configuration of the cell 202 _ij constituting the bidirectional AC switch 104 is shown in FIG. Represented as shown.

As shown in FIGS. 9 and 10, the bidirectional AC switch 104 according to the third embodiment includes two MOSFETs Q1 _ij and Q2 _ij whose sources are connected to each other, and a drain D1 _{ij of the} MOSFET Q1 _ij , the configuration including the surge suppressor circuit 26 _i which was facing the two _{ABD1 ij} · ABD2 ij between the drain _{D2 ij} of MOSFET Q2 _ij as a unit cell _{202 ij,} and connecting the unit cells _{202 ij} in m series × n parallel configuration Is provided.

The gate drive circuit 15 _i includes an E / O converter 22 _i connected to the input terminals 18A and 18B, an isolated DC / DC converter 16 _i supplied with a DC voltage (DC + 24V), and an E / O converter. an optical fiber 17 _i which is connected to the transmitter 22 _i, through an optical fiber 17 _i is connected to E / O converter 22 _i, and the insulation type DC / DC converter 16 _i and connected the O / E converter 14 _i and an FET driver 12 _i1 connected to the O / E converter 14 _i . Between the E / O converter 22 _i and the O / E converter 14 _i , a withstand voltage equal to or higher than that of the insulated DC / DC converter 16 _i is secured.

  According to the bidirectional AC switch 104 according to the third embodiment, for example, a bidirectional AC switch with a contact rated load AC (700 × m) V / (5 × n) A can be provided.

  According to the third embodiment, the noise resistance on the control side is enhanced by securing a sufficient insulation distance by the optical fiber, and the current drop due to the gate voltage drop, the gate breakdown due to the gate overvoltage, and the deterioration of the switching characteristics are suppressed. The bidirectional AC switch can be configured.

In addition, according to the third embodiment, it is difficult to fail by guaranteeing the applied voltage by the surge killer circuit, excellent in linearity of voltage-current characteristics, small and inexpensive, long life, high withstand voltage, large current capacity. Thus, it is possible to provide a bidirectional AC switch having a non-voltage contact that is capable of high-speed response and reduces the risk of destruction of the SiC-MOSFET due to a large voltage or non-uniform balance of voltage division.
(Configuration example of semiconductor device)
-SiC-DIMOSFET-
11 is an example of a semiconductor device 200 applicable to the bidirectional AC switch according to the first to third embodiments, and a schematic cross-sectional structure of a SiC-DI (Double Implanted) MOSFET is represented as shown in FIG. Is done.

As shown in FIG. 11, the SiC-DIMOSFET applicable to the bidirectional AC switch according to the first to third embodiments includes an n ⁺ SiC substrate 124 and an n ⁻ epitaxially grown on the n ⁺ SiC substrate 124. Drift layer 126, p body region 128 formed on the surface side of n ⁻ drift layer 126, n ⁺ source region 130 formed on the surface of p body region 128, and n ⁻ drift layer between p body regions 128 A gate insulating layer 132 disposed on the surface of 126, a gate electrode 138 disposed on the gate insulating layer 132, a source electrode 134 electrically connected to the n ⁺ source region 130 and the p body region 128; A drain electrode 136 electrically connected to the surface of the n ⁺ SiC substrate 124 opposite to the n ⁻ drift layer 126 is provided.

In FIG. 11, in the semiconductor device 200, a p body region 128 and an n ⁺ source region 130 formed on the surface of the p body region 128 are formed by double ion implantation (DI), and the source pad electrode SP is n ^+. Connected to source electrode 134 connected to source region 130 and p body region 128. The gate pad electrode GP (not shown) is connected to the gate electrode 138 disposed on the gate insulating layer 132. Further, as shown in FIG. 11, the source pad electrode SP / source electrode 134 and the gate pad electrode GP (not shown) are arranged on a passivation interlayer insulating film 144 that covers the surface of the semiconductor device 200.
-SiC-TMOSFET-
It is an example of the semiconductor device 200 applicable to the bidirectional | two-way AC switch which concerns on the 1st-3rd embodiment, Comprising: The typical cross-section of SiC-TMOSFET is represented as shown in FIG.

As shown in FIG. 12, the SiC-TMOSFET applicable to the bidirectional AC switch according to the first to third embodiments includes an n ⁺ SiC substrate 124 and an n ⁻ epitaxially grown on the n ⁺ SiC substrate 124. Drift layer 126N, p body region 128 formed on the surface side of n ⁻ drift layer 126N, n ⁺ source region 130 formed on the surface of p body region 128, p body region 128, and n ⁻ Trench gate electrode 138TG formed through gate insulating layer 132 and interlayer insulating films 144U and 144B in the trench formed up to drift layer 126N, and source electrode 134 connected to source region 130 and P body region 128, , the ⁿ + SiC substrate 124, n ^- are electrically connected to the opposite side of the surface and the drift layer 126N And a drain electrode 136.

  In FIG. 12, in the semiconductor device 200, a trench gate electrode 138TG formed through the gate insulating layer 132 and the interlayer insulating films 144U and 144B is formed in the trench formed through the p body region 128 to the semiconductor substrate 126N. The source pad electrode SP is connected to the source electrode 134 connected to the source region 130 and the P body region 128. The gate pad electrode GP (not shown) is connected to the gate electrode 138 disposed on the gate insulating layer 132. Further, the source pad electrode SP / source electrode 134 and the gate pad electrode GP (not shown) are disposed on a passivation interlayer insulating film 144U that covers the surface of the semiconductor device 200, as shown in FIG.

  Since the SiC-TMOSFET does not have a junction resistance extending from the p body region 128 in the drain current path, it is possible to provide a FET having a lower on-resistance than that of the SiC-DMOSFET, and more than 100 A per element. It is also possible to tolerate a drain pulse current.

  Further, a GaN-based FET or the like can be applied to the semiconductor device 200 applicable to the bidirectional AC switch according to the first to third embodiments instead of the SiC-based MOSFET.

  Since the SiC device has a high breakdown electric field (for example, about 3 MV / cm and about 3 times that of Si), the drift layer is made thinner and the carrier concentration is set higher than that of Si. Can withstand pressure. Due to the difference in dielectric breakdown electric field, the peak electric field strength of the SiC-MOSFET can be set higher than the peak electric field strength of the Si-MOSFET.

In the SiC-MOSFET, the resistance value of the n ⁻ drift layers 126 and 126N can be reduced and the on-resistance can be lowered by the merit of both the carrier concentration and the film thickness, and the chip area can be reduced (smaller chip size). Is possible. Furthermore, since the withstand voltage and on-resistance comparable to Si-IGBT can be realized with the MOSFET structure that is a unipolar device, it is considered that high withstand voltage and high speed switching can be performed, and reduction of switching loss can be expected.

As described above, according to the present embodiment, the voltage-current characteristic linearity is excellent, and it is a compact, inexpensive, long-life, high withstand voltage, high-current capacity, non-voltage contact bidirectional AC switch. Can be provided.
[Other embodiments]
As described above, the first to third embodiments have been described. However, it should be understood that the description and drawings constituting a part of this disclosure are exemplary and limit the present invention. Absent. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

Embodiments of the present invention will be described below with reference to the drawings.
[Example 1]
FIG. 13 is a diagram showing a form of the first embodiment of the present invention.

  In FIG. 13, a semiconductor circuit breaker 1 (1A) is a power supply line that connects R1, S1, T1 of the three-phase AC input unit 2 on the input side and R2, S2, T2 of the three-phase AC output unit 3 on the output side. The SiC bidirectional AC switch R, the SiC bidirectional AC switch S, and the SiC bidirectional AC switch T, which are independently installed in 4, 5, and 6, are provided. That is, this semiconductor circuit breaker 1 is a semiconductor circuit breaker provided with a semiconductor switch disposed on a power supply line that supplies power from a power supply device of a three-phase AC input device to a load device of an output device. Details of a typical case of the SiC bidirectional AC switch will be described later. The SiC bidirectional AC switch is connected in m series × n parallel, and the absolute value of the voltage applied between the drain and the source is 1. It has a feature that is set to be 0V or less. The SiC bidirectional AC switch includes a bidirectional AC switch composed of three SiC-MOSFETs provided independently for each phase of the three-phase alternating current provided in each power supply line that supplies power of each phase. Each bidirectional AC switch has a maximum current of 100A and is connected in parallel with 20 or more current-voltages which are non-voltage contacts capable of high-speed response that are turned on at the moment when the voltages on the input side and output side match. With characteristics.

  The semiconductor circuit breaker 1 is a bidirectional AC switch composed of three SiC-MOSFETs that are independently installed for each phase of a three-phase alternating current provided in each power supply line for supplying power for each phase. Composed.

  A measuring device for measuring the voltage on the input side and the output side of each bidirectional AC switch is provided. In the drawing, high-voltage probes R1, S1, and T1 are connected to input-side power supply lines 4, 5, and 6 as measuring devices, and output-side power supply lines 4, 5, and 6 are connected to high-voltage probes R2, S2, and T2 is connected.

  A control circuit A is provided for performing ON / OFF processing of each bidirectional AC switch from the open / close command signal 8 and the voltage measurement state of each bidirectional AC switch. The voltages measured by the high voltage probes R1, S1, T1 and the high voltage probes R2, S2, T2 are input to the control circuit A.

The control signal formed by the control circuit A is transmitted to the SiC bidirectional AC switch R, the SiC bidirectional AC switch S, and the SiC bidirectional AC switch T via the wirings 11, 12, and 13.
Description of operation In the initial state, the semiconductor circuit breaker 1 is in the “open” state when the switching command signal 8 is off, and the control circuit A has three SiC bidirectional AC switches R, SiC bidirectional AC switches S and SiC. All bidirectional AC switches T are turned off.
2. In this state, when the open / close command signal 8 is turned on from off, the control circuit A turns on the SiC bidirectional AC switch R, the SiC bidirectional AC switch S, and the SiC bidirectional AC switch T of each phase.
3. Therefore, when there is no three-phase AC distortion, control circuit A turns on all three SiC bidirectional AC switches R, SiC bidirectional AC switch S, and SiC bidirectional AC switch T at the same time. When there is distortion, the control circuit A sequentially delays the three SiC bidirectional AC switches R, the SiC bidirectional AC switch S, and the SiC bidirectional AC switch T with a time delay of about several tens of seconds to several milliseconds. Will be turned on.
4. When all of the three SiC bidirectional AC switches R, the SiC bidirectional AC switch S, and the SiC bidirectional AC switch T are turned on, the semiconductor circuit breaker 1 is turned on.
5). When the semiconductor circuit breaker 1 is in the “ON” state, the control circuit A calculates the current value flowing through each bidirectional AC switch from the voltage measurement result of each phase. For example, when the current value exceeds a specified value, an “overcurrent trip operation” is performed to turn off all bidirectional AC switches, thereby bringing the semiconductor circuit breaker 1 into an “open” state, and peripheral devices. To protect.
6). Or when the deviation beyond a regulation value is detected in the value of the current flowing in each phase of the three-phase alternating current, the semiconductor circuit breaker 1 is also put into the “open” state, assuming that a correlation short circuit or a leakage has occurred.

  In this way, when the open / close command signal 8 is on, the control circuit A turns on or off at the measured moment on the input side and output side of the three bidirectional AC switches, and responds with a predetermined voltage difference. The bi-directional AC switch of the phase is kept on or off, and the open state or the on-state between the power supply device and the load device is selected from the three states of the bi-directional AC switch of each phase, which is the on or off state. Form.

  When the control circuit A is in the on state between the power supply device and the load device when the opening / closing command signal 8 is on, the voltages on the input side and the output side of the three bidirectional AC switches are simultaneously or When the voltage at the moment of coincidence is measured with a time delay, the bidirectional AC switch of each phase is turned on, and the current value flowing through each bidirectional AC switch is calculated from the measured voltage difference of each phase. When the current value exceeds the specified value by comparing the current value with the specified value, all the bidirectional AC switches are changed from the on state to the off state, thereby forming the open state from the on state.

  By using the semiconductor circuit breaker 1 according to the present embodiment, the bi-directional AC switch of each phase is turned on from off when the input voltage and the output side voltage are completely matched. The current can be made zero.

  For example, when applied as a circuit breaker for a power receiving facility, a “rushing” operation with zero inrush current is possible even when a voltage remains on the load side due to the influence of a capacitive load.

  For example, when it is applied as a generator main circuit breaker, the inrush current at the time of insertion can be made zero.

In the semiconductor circuit breaker according to the present embodiment, since it can be turned on instantaneously (which means about 100 ns), it is measured that the voltages on the input side and the output side are exactly the same. Since the “open” operation can be performed, the load can be disconnected from the system before the accident current occurs. Since each phase current can always be measured and monitored, a protective relay function for overcurrent protection, ground fault protection, etc. can be incorporated at low cost. Since the bidirectional AC switch using the SiC-MOSFET of this embodiment has an impedance characteristic that suppresses the inrush current when it is turned on, it can be used in combination with bumpless.
[Example 2-1]
FIG. 14 is a diagram showing a form of Example 2-1 of the present invention.

  In FIG. 14, the semiconductor circuit breaker 1 </ b> B is independently installed on power supply lines 4, 5, 6 that connect R <b> 1, S <b> 1, T <b> 1 of the input side three-phase AC input unit 2 and DP of the output side DC output unit 3. Each SiC bidirectional AC switch R, SiC bidirectional AC switch S, and SiC bidirectional AC switch T are provided. That is, this semiconductor circuit breaker 1 is a semiconductor circuit breaker provided with a semiconductor switch disposed on a power supply line that supplies power from a power supply device of a three-phase AC input device to a load device of an output device. Details of a typical case of the SiC bidirectional AC switch will be described later. However, the SiC bidirectional AC switch is connected in parallel at a maximum current of 100 A, and the absolute voltage of the voltage applied between the drain and the source can be reduced. A feature is set such that the value is 1.0 V or less. The SiC bidirectional AC switch includes a bidirectional AC switch composed of three SiC-MOSFETs provided independently for each phase of the three-phase alternating current provided in each power supply line that supplies power of each phase. Each bidirectional AC switch has a current-voltage characteristic that is a non-voltage contact capable of high-speed response that is turned on at the moment when the voltages on the input side and the output side match.

  The power supply lines 4, 5, 6 on the output side are short-circuited to form a power supply line 7.

  The semiconductor circuit breaker 1 is a bidirectional AC switch composed of three SiC-MOSFETs that are independently installed for each phase of a three-phase alternating current provided in each power supply line for supplying power for each phase. Composed.

  A measuring device for measuring the voltage on the input side and the output side of each bidirectional AC switch is provided. In the drawing, high-voltage probes R1, S1, and T1 are connected to input-side power supply lines 4, 5, and 6 as measurement devices, and a high-voltage probe D2 is connected to an output-side power supply line 7.

  A control circuit B is provided for performing ON / OFF processing of each bidirectional AC switch from the open / close command signal 8 and the voltage measurement state of each bidirectional AC switch. The voltages measured by the high voltage probes R1, S1, T1 and the high voltage probe D2 are input to the control circuit B.

The control signal formed by the control circuit B is transmitted to the SiC bidirectional AC switch R, the SiC bidirectional AC switch S, and the SiC bidirectional AC switch T via the wirings 11, 12, and 13.
Description of operation In the initial state, the semiconductor circuit breaker 1B is in the “open” state when the switching command signal 8 is off, and the control circuit A has three SiC bidirectional AC switches R, SiC bidirectional AC switches S, and SiC. All bidirectional AC switches T are turned off.
2. When the control circuit B enters the “ON” state by the open / close command signal 8, the control circuit B first inputs the measured voltage on the bidirectional AC switch input side of each phase, and selects the phase having the highest voltage.
3. Next, input the measured “DC output side voltage” and turn it on at the moment when “the highest phase voltage” matches the “DC output side voltage”, then “the highest phase voltage”> “DC output side voltage” The bi-directional AC switch of the phase that satisfies the above condition is kept on.
4.2.3. When the above operation is performed with a sampling period of about 100 ns, the voltage value of the output voltage DP becomes equal to the DC voltage value obtained by half-wave rectification as shown in FIG.

  In this way, when the open / close command signal 8 is on, the control circuit B turns the corresponding phase bidirectional AC switch into a corresponding phase bidirectional AC switch with a predetermined voltage difference measured on the input side and output side of the three bidirectional AC switches. The on or off state is maintained, and the open state or the on state is formed between the power supply device and the load device from the three states of the on or off state formed in the bidirectional AC switch of each phase.

In addition, when the control circuit B is in the on state when the open / close command signal is on, the voltage on the input side of the bidirectional AC switch of each phase is measured, and the phase having the highest voltage is selected, Measure the DC output side voltage, turn on the moment when the highest phase voltage matches the DC output voltage, and continue to turn on the bidirectional AC switch of the corresponding phase in the state where the highest phase voltage> DC output voltage is satisfied Then, the DC output side voltage is generated, the other two-phase bidirectional AC switch is turned off, and positive output half-wave rectification is performed.
[Example 2-2]
FIG. 16 is a diagram showing a form of Example 2-2 of the present invention.

  In FIG. 16, the semiconductor circuit breaker 1 </ b> C is independently installed on the power supply lines 4, 5, 6 that connect R <b> 1, S <b> 1, T <b> 1 of the input side three-phase AC input unit 2 and DN of the output side DC output unit 3. Each SiC bidirectional AC switch R, SiC bidirectional AC switch S, and SiC bidirectional AC switch T are provided. In other words, the semiconductor circuit breaker 1 is a semiconductor circuit breaker including a semiconductor switch disposed on a power supply line that supplies power from a power supply device of a three-phase AC input device to a load device of an output device. Details of a typical case of the SiC bidirectional AC switch will be described later, but the SiC bidirectional AC switch is connected in parallel at a maximum current of 100 A, and the absolute value of the voltage applied between the drain and the source. Is set to be 1.0 V or less. The SiC bidirectional AC switch includes a bidirectional AC switch composed of three SiC-MOSFETs provided independently for each phase of the three-phase alternating current provided in each power supply line that supplies power of each phase. Each bidirectional AC switch has a current-voltage characteristic that is a non-voltage contact capable of high-speed response that is turned on at the moment when the voltages on the input side and the output side match.

  The power supply lines 4, 5, 6 on the output side are short-circuited to form a power supply line 7.

  The semiconductor circuit breaker 1 is a bidirectional AC switch composed of three SiC-MOSFETs that are independently installed for each phase of a three-phase alternating current provided in each power supply line for supplying power for each phase. Composed.

  A measuring device for measuring the voltage on the input side and the output side of each bidirectional AC switch is provided. In the drawing, high-voltage voltage dividers R1, S1, and T1 are connected to input-side power supply lines 4, 5, and 6 as measurement devices, and high-voltage voltage divider D2 is connected to an output-side power supply line 7.

  A control circuit C is provided for performing ON / OFF processing of each bidirectional AC switch from the open / close command signal 8 and the voltage measurement state of each bidirectional AC switch. The voltages measured by the high voltage dividers R1, S1, T1 and the high voltage divider D2 are input to the control circuit C.

A control signal formed by the control circuit C is transmitted to the SiC bidirectional AC switch R, the SiC bidirectional AC switch S, and the SiC bidirectional AC switch T via the wirings 11, 12, and 13.
Description of operation In the initial state, the semiconductor circuit breaker 1 is in the “open” state when the switching command signal 8 is OFF, and the control circuit A has both the three SiC bidirectional AC switches R, the SiC bidirectional AC switches S and SiC. All the direction AC switches T are turned off.
2. When the control circuit C enters the “ON” state by the open / close command signal 8, the control circuit C first inputs the measured voltage on the bidirectional AC switch input side of each phase, and selects the phase having the lowest voltage.
3. Next, the measured “DC output side voltage” is input and turned ON at the moment when “lowest phase voltage” matches “DC output side voltage”, and “lowest phase voltage” <“DC output side voltage” Continue on in the state where
4.2.3. When the above operation is performed with a sampling period of about 100 ns, the voltage value DN of the output voltage becomes equal to the DC voltage value obtained by half-wave rectification as shown in FIG.

  Thus, when the open / close command signal 8 is turned on, the control circuit C turns on the bidirectional AC switch of the corresponding phase based on the measured voltage difference between the input side and the output side of the three bidirectional AC switches. Alternatively, an off state is formed, and an open state or an on state is formed between the power supply device and the load device from the three states of the on or off state formed in the bidirectional AC switch of each phase.

When the control circuit C is in the on state when the open / close command signal 8 is on, the voltage on the input side of the bidirectional AC switch of each phase is measured, and the phase having the lowest voltage is selected. Measure the DC output side voltage, turn on at the moment when the lowest phase voltage matches the DC output voltage, and turn on the bidirectional AC switch for the corresponding phase in the state where the lowest phase voltage <DC output voltage is satisfied The state continues, a DC output side voltage is generated, the other two-phase bidirectional AC switch is turned off, and negative output half-wave rectification is performed.
[Example 2-3]
A semiconductor circuit breaker BC characterized by performing full wave rectification by combining positive output half wave rectification and negative output half wave rectification is provided. As shown in FIG. The value is equivalent to wave rectification.

  FIG. 19 is a diagram illustrating a configuration of a semiconductor full-wave rectifier.

  In FIG. 19, a semiconductor half-wave rectifier 21 shows the configuration of FIG. 14, and a semiconductor half-wave rectifier 22 shows the configuration of FIG.

  When the control circuit B is in the ON state when the open / close command signal is ON, measure the voltage on the input side of the bidirectional AC switch of each phase, select the phase with the highest voltage, and select the DC output side voltage When the condition of the highest phase voltage> DC output voltage is satisfied, the corresponding phase bidirectional AC switch is turned on, the DC output side voltage is generated, and the other two-phase bidirectional AC switch is turned on. Turn off and perform positive output half-wave rectification.

When the control circuit C is in the on state when the open / close command signal is ON, the voltage on the input side of the bidirectional AC switch of each phase is measured, the phase having the lowest voltage is selected, and the DC output Measure the side voltage, turn on at the moment when the lowest phase voltage coincides with the DC output voltage, continue to turn on the bidirectional AC switch of the corresponding phase in the state that the condition of the lowest phase voltage <DC output voltage is satisfied, A DC output side voltage is generated, the other two-phase bidirectional AC switch is turned off, and negative output half-wave rectification is performed. This is converted to positive output half-wave rectification.
[Example 3-1]
FIG. 20 is a diagram showing a form of Example 3-1 of the present invention.

  In FIG. 20, the semiconductor circuit breaker 1B is independently installed on the power supply lines 4, 5, 6 that connect R1, S1, T1 of the three-phase AC input unit 2 on the input side and DP of the DC output unit 3 on the output side. Each SiC bidirectional AC switch R, SiC bidirectional AC switch S, and SiC bidirectional AC switch T are provided. That is, this semiconductor circuit breaker 1 is a semiconductor circuit breaker provided with a semiconductor switch disposed on a power supply line that supplies power from a power supply device of a three-phase AC input device to a load device of an output device. Details of a typical case of the SiC bidirectional AC switch will be described later. However, the SiC bidirectional AC switch is connected in parallel at a maximum current of 100 A, and the absolute voltage of the voltage applied between the drain and the source can be reduced. A feature is set such that the value is 1.0 V or less. The SiC bidirectional AC switch includes a bidirectional AC switch composed of three SiC-MOSFETs provided independently for each phase of the three-phase alternating current provided in each power supply line that supplies power of each phase. Each bidirectional AC switch has a current-voltage characteristic that is a non-voltage contact capable of high-speed response that is turned on at the moment when the voltages on the input side and the output side match.

  The power supply lines 4, 5, 6 on the output side are short-circuited to form a power supply line 7.

  The semiconductor circuit breaker 1 is a bidirectional AC switch composed of three SiC-MOSFETs that are independently installed for each phase of a three-phase alternating current provided in each power supply line for supplying power for each phase. Composed.

  A measuring device for measuring the voltage on the input side and the output side of each bidirectional AC switch is provided. In the drawing, high-voltage probes R1, S1, and T1 are connected to input-side power supply lines 4, 5, and 6 as measurement devices, and a high-voltage probe D2 is connected to an output-side power supply line 7.

  A control circuit E is provided for performing ON / OFF processing of each bidirectional AC switch from the open / close command signal 8 and the voltage measurement state of each bidirectional AC switch. The voltages measured by the high voltage probes R1, S1, T1 and the high voltage probe D2 are input to the control circuit E.

  The control signal formed by the control circuit E is transmitted to the SiC bidirectional AC switch R, the SiC bidirectional AC switch S, and the SiC bidirectional AC switch T via the wirings 11, 12, and 13.

The configuration is substantially the same as the configuration shown in FIG. 14, but an “output voltage setting circuit 31” is added and the output voltage setting value is set in the control circuit E.
Description of operation In the initial state, the semiconductor circuit breaker 1E is in the “open” state when the switching command signal 8 is off, and the control circuit E has both the three SiC bidirectional AC switches R, the SiC bidirectional AC switches S and SiC. All the direction AC switches T are turned off.
2. When the control circuit B enters the “ON” state by the open / close command signal 8, the control circuit B first inputs the measured voltage on the bidirectional AC switch input side of each phase, and selects the phase having the highest voltage.
3. Next, input the measured “DC output side voltage”, select a phase AC switch that satisfies the condition “highest phase voltage”> “DC output side voltage”, and set the “DC output side voltage” to It is determined whether it is higher than the voltage set value from the “output voltage setting circuit 31”. At this time, when the “DC output side voltage” is higher than the voltage setting value from the “output voltage setting circuit 31”, the bidirectional AC switch is not turned on. Conversely, when the “DC output side voltage” is lower than the voltage setting value from the “output voltage setting circuit 31”, the bidirectional AC switch of the phase having the highest voltage selected is turned on.
4.2. And 3. When the above operation is performed at a sampling period of about 100 ns, the voltage value of the output voltage DP can be maintained at a value substantially equal to the DC voltage value corresponding to the voltage setting value of the “output voltage setting value”. For example, when the semiconductor circuit breaker of Example 3-1 is inserted into a three-phase AC200V line and the voltage setting value from the “output voltage setting circuit” is set to DC250V, the DP voltage value can be maintained around DC250V. In Example 2-1, the DP voltage value is maintained at about DC283V.

  In this way, when the control circuit E is ON, the corresponding phase bidirectional AC switch is turned on based on the measured voltage difference between the input side and the output side of the three bidirectional AC switches. Alternatively, an off state is formed, and an open state or an on state is formed between the power supply device and the load device from the three states of the on or off state formed in the bidirectional AC switch of each phase.

Further, when the control circuit E is in the on state when the open / close command signal 8 is on, the voltage on the input side of the bidirectional AC switch of each phase is measured, and the phase having the highest voltage is selected. Measure the DC output side voltage, turn on at the moment when the condition of the highest phase voltage> DC output voltage is met, and the DC output voltage matches the output set voltage, and respond in the state of DC output voltage <output set voltage The bi-directional AC switch of the phase is kept on, the on-DC output side voltage is generated, it is turned off when the DC output voltage> the output set voltage, and the other two-phase bi-directional AC switches are also turned on under the same conditions.・ By turning off, positive output half-wave rectification is performed.
[Example 3-2]
Similarly to Example 3-1, with reference to Example 2-2, when the control circuit is in the on state when the open / close command signal is on, the control circuit on the input side of the bi-directional AC switch of each phase Measure the voltage, select the phase with the highest voltage, measure the DC output side voltage, and at the moment when the condition of the lowest phase voltage <DC output voltage is satisfied and the DC output voltage matches the output setting voltage Turns on and continues to turn on the bidirectional AC switch of the corresponding phase in the state of DC output voltage <output set voltage, generates on DC output side voltage, and turns off when DC output voltage> output set voltage The other two-phase bidirectional AC switches can be turned on / off under the same conditions to perform negative output half-wave rectification.
[Example 3-3]
FIG. 19 shows a configuration of a semiconductor full-wave rectifier by applying Examples 3-1 and 3-2 to two half-wave rectifiers. A semiconductor circuit breaker BC is provided that performs full-wave rectification by combining positive output half-wave rectification and negative output half-wave rectification, and a voltage value between DC output terminals is equal to an output set voltage value. Value.

  DESCRIPTION OF SYMBOLS 1, 1A, 1B, 1C, 1D, 1E ... Semiconductor circuit breaker, 2 ... Three-phase alternating current output part, 3 ... Output part, 4, 5, 6, 7 ... Power supply line, 8 ... Opening / closing command signal, A, B , C, D, E ... control circuit, R, S, T ... SiC bidirectional AC switch, R1, R2, S1, S2, T1, T2 ... high voltage probe, voltage measuring device.

Claims (8)

In a semiconductor circuit breaker comprising a semiconductor switch arranged on a power supply line for supplying power from a three-phase AC input side device to an output side device,
A semiconductor switch is provided with a bidirectional AC switch by three SiC-MOSFETs installed independently for each phase of the three-phase alternating current provided in each power supply line for supplying power of each phase. The switch has a current-voltage characteristic that is a no-voltage contact capable of high-speed response that is turned on at the measurement moment when the input side voltage and the output side voltage are matched, with 20 or more switches connected in parallel at a maximum current of 100A.
A measuring device for measuring the voltage on the input side and output side of each bidirectional AC switch is provided,
A control circuit that performs ON / OFF processing of each bidirectional AC switch from the open / close command signal and the voltage measurement state of each bidirectional AC switch,
When the open / close command signal is on, the control circuit turns on or off at the measured moment of each input side and output side of the three bidirectional AC switches, and when the voltage difference is a predetermined voltage, An on or off state is maintained, and an open state or a closed state is formed between the three-phase AC input side device and the output side device from the three states of the on or off state formed in the bidirectional AC switch of each phase. A semiconductor circuit breaker characterized by In a semiconductor circuit breaker comprising a semiconductor switch arranged on a power supply line for supplying power from a three-phase AC input side device to an output side device,
A semiconductor switch is provided with a bidirectional AC switch by three SiC-MOSFETs installed independently for each phase of the three-phase alternating current provided in each power supply line for supplying power of each phase. The switch has a current-voltage characteristic that is a no-voltage contact capable of high-speed response that is turned on at the moment when the input side voltage and the output side voltage match with each other with 20 or more connected in parallel at a maximum current of 100A.
A measuring device for measuring the voltage on the input side and output side of each bidirectional AC switch is provided,
A control circuit for performing ON / OFF processing of each bidirectional AC switch from the open / close command signal and the voltage measurement results on the input side and output side of each bidirectional AC switch,
When the control circuit is in the on state between the three-phase AC input side device and the output side device when the open / close command signal is ON, the voltages on the input side and the output side of the three bidirectional AC switches are simultaneously or When the voltage at the moment of coincidence is measured with a time delay, the bidirectional AC switch of each phase is turned on, and the current value flowing through each bidirectional AC switch is calculated from the measured voltage difference of each phase. The semiconductor circuit is characterized in that when the current value exceeds a specified value by comparing the current value with a specified value, all bidirectional AC switches are turned from the on state to the off state to form the open state from the on state. vessel. In a semiconductor circuit breaker comprising a semiconductor switch arranged on a power supply line for supplying power from a three-phase AC input side device to an output side device,
A semiconductor switch is provided with a bidirectional AC switch by three SiC-MOSFETs installed independently for each phase of the three-phase alternating current provided in each power supply line for supplying power of each phase. 20 or more switches are connected in parallel, and have a current-voltage characteristic that is a non-voltage contact capable of high-speed response that is turned on at the moment when the voltages on the input side and the output side coincide with each other. The side is short-circuited,
A measuring device for measuring the voltages on the three-phase AC input side and DC output side of the bidirectional AC switch for each phase is provided,
It has a control circuit that performs on / off processing of each bidirectional AC switch from the open / close command signal and the voltage difference measurement result,
When the control circuit is in the on state when the open / close command signal is on, measure the voltage on the input side of the bi-directional AC switch of each phase, select the phase with the highest voltage, and select the DC output side voltage Is turned on at the moment when the highest phase voltage coincides with the DC output voltage, and the bidirectional AC switch of the corresponding phase is kept on in the state where the highest phase voltage> DC output voltage is satisfied. A semiconductor circuit breaker characterized by generating an output side voltage and turning off the other two-phase bidirectional AC switch to perform positive output half-wave rectification. In a semiconductor circuit breaker comprising a semiconductor switch arranged on a power supply line for supplying power from a three-phase AC input side device to an output side device,
A semiconductor switch is provided with a bidirectional AC switch by three SiC-MOSFETs installed independently for each phase of the three-phase alternating current provided in each power supply line for supplying power of each phase. The switch has a current-voltage characteristic that is a no-voltage contact that can be turned on at the moment when the input side voltage and the output side voltage coincide with each other with 20 or more connected in parallel at a maximum current of 100A. The output side of the direction AC switch is short-circuited,
A measuring device for measuring the voltages on the three-phase AC input side and DC output side of the bidirectional AC switch for each phase is provided,
It has a control circuit that performs on / off processing of each bidirectional AC switch from the open / close command signal and the voltage difference measurement result,
When the control circuit is in the on state when the open / close command signal is on, measure the voltage on the input side of the bi-directional AC switch of each phase, select the phase with the lowest voltage, and select the DC output side voltage Is turned on at the moment when the lowest phase voltage matches the DC output voltage, and the bi-directional AC switch of the corresponding phase is kept on while the condition of the lowest phase voltage <DC output voltage is satisfied. A semiconductor circuit breaker characterized in that a two-phase bidirectional AC switch is turned off to perform negative output half-wave rectification. The positive output half-wave rectification output from the semiconductor circuit breaker according to claim 3 is input to the + side of the output-side device, and the negative output half-wave rectification output from the semiconductor breaker according to claim 4 Is input to the negative side of the output side device, and full wave rectification is performed by switching the positive output half wave rectification and the negative output half wave rectification for each half wave of the corresponding phase of the three-phase AC input side device. A semiconductor circuit breaker characterized by performing. In a semiconductor circuit breaker comprising a semiconductor switch arranged on a power supply line for supplying power from a three-phase AC input side device to an output side device,
A semiconductor switch is provided with a bidirectional AC switch by three SiC-MOSFETs installed independently for each phase of the three-phase alternating current provided in each power supply line for supplying power of each phase. The switch has a current-voltage characteristic that is a no-voltage contact that can be turned on at the moment when the input side voltage and the output side voltage coincide with each other with 20 or more connected in parallel at a maximum current of 100A. The output side of the direction AC switch is short-circuited,
A measuring device for measuring the voltages on the three-phase AC input side and DC output side of the bidirectional AC switch for each phase is provided,
It has a control circuit that performs on / off processing of each bidirectional AC switch from the open / close command signal and the voltage difference measurement result,
Equipped with an output voltage setting circuit that sets the output voltage setting value in the control circuit,
When the control circuit is in the on state when the open / close command signal is on, measure the voltage on the input side of the bi-directional AC switch of each phase, select the phase with the highest voltage, and select the DC output side voltage Is turned on at the moment when the condition of the highest phase voltage> DC output voltage is met, and the DC output voltage matches the output setting voltage, and the DC output voltage is less than the output setting voltage. Generates a side voltage, turns off when DC output voltage> output set voltage, and turns on / off the other two-phase bidirectional AC switches under the same conditions to perform positive output half-wave rectification A semiconductor circuit breaker characterized by In a semiconductor circuit breaker having a semiconductor switch arranged on a power supply line for supplying power from a three-phase AC input side device to an output side device, a semiconductor switch is provided on each power supply line for supplying power of each phase. In addition, two bidirectional AC switches by three SiC-MOSFETs installed independently for each phase of the three-phase alternating current are provided, and each of the bidirectional AC switches is connected in parallel at a maximum current of 100 A, and the input side It has a current-voltage characteristic that is a non-voltage contact that can be turned on at the moment when the output side voltage matches and
The output side of each bidirectional AC switch is short-circuited,
A measuring device for measuring the voltages on the three-phase AC input side and DC output side of the bidirectional AC switch for each phase is provided,
It has a control circuit that performs on / off processing of each bidirectional AC switch from the open / close command signal and the voltage difference measurement result,
Equipped with an output voltage setting circuit that sets the output voltage setting value in the control circuit,
When the control circuit is in the on state when the open / close command signal is on, measure the voltage on the input side of the bi-directional AC switch of each phase, select the phase with the lowest voltage, and select the DC output side voltage When the condition of the lowest phase voltage <DC output voltage is satisfied and the DC output voltage matches the output setting voltage, it is turned on at the moment when the DC output voltage is less than the output setting voltage. Generate output side voltage, turn off when DC output voltage> output set voltage, turn on / off other two-phase bidirectional AC switch under the same conditions, perform negative output half-wave rectification A semiconductor circuit breaker characterized by The negative output half-wave rectification output from the semiconductor circuit breaker according to claim 7, wherein the positive output half-wave rectification output from the semiconductor circuit breaker according to claim 6 is input to the + side of the output-side device. Is input to the negative side of the output side device, and full wave rectification is performed by switching the positive output half wave rectification and the negative output half wave rectification for each half wave of the corresponding phase of the three-phase AC input side device. A semiconductor circuit breaker characterized by performing.

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