JP5405248B2 - Self-excited power conversion device and gate timing adjustment method thereof - Google Patents

Description

  The present invention relates to a self-excited power conversion device and a gate timing adjustment method thereof, and more particularly, a self-excited type using a self-extinguishing semiconductor switching element such as an IGBT (Insulated Gate Bipolar Transistor) connected in series. The present invention relates to a power conversion device and a gate timing adjustment method thereof.

  A self-excited power converter using self-extinguishing semiconductor switching elements connected in series usually has a high voltage specification. For this reason, the drive circuit for supplying a pulse signal to the gate of each self-extinguishing semiconductor switching element requires signal insulation, and is usually supplied with an optical signal.

  The optical signal given to the drive circuit is transmitted from the reference gate signal generator through a light guide (optical fiber). In order to easily adjust individual signals, the number of light guides corresponding to the number of self-extinguishing semiconductor switching devices in series is required.

  On the other hand, the light guide from the reference gate signal generator to the drive circuit is shared, and this signal is branched by the optical distribution circuit on the drive circuit side, and the individual collector voltage of the self-extinguishing semiconductor switching device is detected. Thus, a proposal has been made to maintain voltage balance by performing voltage clamping (see, for example, Patent Document 1).

Japanese Patent Laying-Open No. 2003-33004 (page 2-3, FIG. 1)

  The technique disclosed in Patent Document 1 is a method of subdividing light obtained from an optical cable by an optical distribution circuit. For this reason, it is possible to ensure the on-off signal simultaneity for driving the gate, but as a means to improve the voltage imbalance due to variations in the characteristics of the switching elements, it relies on the voltage clamping function of the gate driving circuit itself, so it is below the clamping voltage. Unbalance cannot be improved, and in some cases, the switching element may be in an overvoltage state.

  In addition, in this way, the light guide is directly distributed, if the number of series of self-extinguishing semiconductor switching elements of the main circuit changes, the light distribution circuit needs to be changed and the LED light intensity of the low-voltage side control circuit is changed. There was a complication that had to be adjusted.

  The present invention has been made in view of the above problems, and reduces the number of optical fibers as light guides, further reduces voltage imbalance due to variations in element characteristics, and easily changes the number of series. It is an object of the present invention to provide a self-excited power conversion device having a drive circuit that can be used and a gate timing adjustment method thereof.

In order to achieve the above object, a self-excited power conversion device according to a first aspect of the present invention includes a plurality of self-extinguishing semiconductor switching elements connected in series for simultaneous switching, and each of the self-extinguishing semiconductor switching devices. A plurality of gate driving circuits for driving the semiconductor switching element, an optical transmission means for remotely supplying and supplying an on / off signal, which is a reference gate signal to be supplied to the gate driving circuit, by the light, and the optical transmission means An optical distribution circuit that receives the transmitted on / off signal and converts it into a first electric signal, distributes the first electric signal to each of the gate drive circuits, and converts it back into an optical signal, and the optical distribution A light guide for supplying a pulse signal, which is an output of each circuit, to each of the plurality of gate driving circuits, and each of the gate driving circuits receives the pulse signal. To the second and converted to an electrical signal, the on-off timing via the timing adjustment means for adjusting so as to respectively drive the plurality of self-turn-off semiconductor switching devices, one substrate of said optical distribution circuit In addition, one of the gate drive circuits is mounted on a single substrate, and the two substrates are arranged in close contact with each other.

A self-excited power conversion device according to a second aspect of the present invention drives a plurality of self-extinguishing semiconductor switching elements connected in series for simultaneous switching and each of the self-extinguishing semiconductor switching elements. A plurality of gate driving circuits, an optical transmission means for remotely supplying an on / off signal as a reference gate signal to be supplied to the gate driving circuit by light, and an on / off signal transmitted by the optical transmission means. An optical distribution circuit that receives the light and converts it into a first electric signal, distributes the first electric signal to each of the gate drive circuits and converts it back into an optical signal, and outputs of each of the optical distribution circuits. A light guide for supplying a pulse signal to each of the plurality of gate drive circuits, and the light distribution circuit includes on / off timing of the distributed first electric signal. Have a timing adjustment means for adjusting, with mounting the optical distribution circuit on one substrate, said implement either of the gate driving circuit on one substrate, so as to disposed in close contact with both the substrate It is characterized in that the.

  Furthermore, a gate timing adjustment method for a self-excited power conversion device according to a third aspect of the present invention includes a plurality of self-extinguishing semiconductor switching elements connected in series for simultaneous switching, and each of the self-extinguishing semiconductor switching devices. A plurality of gate driving circuits for driving the semiconductor switching element; an optical transmission means for supplying an on / off signal, which is a reference gate signal to be supplied to the gate driving circuit, by insulating light remotely; and transmission by the optical transmission means The received on / off signal is received and converted into a first electric signal, and the first electric signal is distributed to each of the plurality of gate driving circuits, and again through timing adjusting means for adjusting the on / off timing, respectively. An optical distribution circuit for converting into an optical signal and a pulse signal that is an output of each of the optical distribution circuits are supplied to the plurality of gate drive circuits, respectively. In the self-excited power conversion device equipped with the light guide, the light distribution circuit arranged in the high-potential side housing is moved to the low-potential side, the light guide is changed and connected to the adjustment light guide, and the necessary control is performed. The timing adjusting means is adjusted by connecting a power source to operate the light distribution circuit.

  According to the present invention, a self-excited power conversion device having a drive circuit that can reduce the number of optical fibers, further reduce voltage imbalance due to variations in element characteristics, and easily change the number of series. And a gate timing adjustment method thereof.

1 is a circuit configuration diagram of a self-excited power conversion device according to Embodiment 1 of the present invention. FIG. 1 is a power supply configuration diagram of an optical / electrical / optical light distribution circuit of a self-excited power conversion device according to a first embodiment of the present invention. FIG. The circuit block diagram of the self-excitation power converter device which concerns on Example 2 of this invention. The circuit block diagram which shows the state at the time of the initial adjustment of the voltage imbalance in the self-excitation power converter device which concerns on Example 2 of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  Hereinafter, a self-excited power conversion device according to a first embodiment of the present invention will be described with reference to FIGS. 1 and 2.

  1 is a circuit configuration diagram of a self-excited power conversion device according to a first embodiment of the present invention. In FIG. 1, the high-potential side housing 1 houses n series-connected switching elements 11 to 1n, gate drive circuits 21 to 2n, light distribution circuit 91, and light guides 41 to 4n. The switching elements 11 to 1n are self-extinguishing semiconductor switching elements such as IGBTs, and are connected in series for simultaneous switching. And the main circuit arm of the power converter of a self-excited power converter is comprised using these switching elements. Note that illustration of other switching elements and main circuit arms connected in series for simultaneous switching is omitted. Further, although the light distribution circuit 91 is shown in the gate drive circuit 21, the light distribution circuit 91 is provided on the substrate of the gate drive circuit 21 in order to minimize the wiring of the light guides 41 to 4 n as will be described later. This means that the substrates are placed in close contact with each other.

  As a gate signal for the switching elements 11 to 1n, a pulse signal obtained by optically converting an on / off signal Pon / Poff given from a reference gate signal generator (not shown) by the light emitting diode 50 is given to the light distribution circuit 91 while being insulated by the light guide 4. ing. That is, the light emitting diode 50 and the light guide 4 constitute an optical transmission means. Then, the optical distribution circuit 91 supplies pulse signals obtained by optical conversion to the gate drive circuits 21 to 2n via the light guides 41 to 4n, respectively.

  The optical distribution circuit 91 receives the optical signal given from the light guide 4 by the optical receiver 30 and converts it into an electric signal, distributes the electric signal by the electric buffer circuits 71 to 7n, and the optical transmitters 51 to 5n respectively. The optical signal is converted into an optical signal. That is, the light distribution circuit 91 constitutes a light / electricity / light distribution circuit.

  The optical signals output from the optical transmitters 51 to 5n are given to the optical receivers 31 to 3n of the gate drive circuits 21 to 2n through the light guides 41 to 4n, respectively. The pulse signals converted into electrical signals by the optical receivers 31 to 3n are transmitted to the amplifying units 81 to 8n via the timing adjusters 61 to 6n, respectively. The amplifiers 81 to 8n drive the switching elements 11 to 1n, respectively.

  FIG. 2 is a power supply configuration diagram of the light / electricity / light optical distribution circuit of the self-excited power conversion device according to the first embodiment. The control power source of the light / electricity / light optical distribution circuit 91 is obtained from the direct-current voltage VCC via the DC / DC converter 91S. On the other hand, the control power supply of the gate drive circuit 21 is obtained from the direct-current voltage VDD via the DC / DC converter 21S. As shown in the figure, these control power supplies are shared as Vin1. As a result, the potential of the control power supply of the light distribution circuit 91 is fixed, and as a result, the electric buffer circuits 71 to 7n can operate stably.

  The DC / DC converter 21S of the gate drive circuit 21 stops the power input to the light distribution circuit 91 by light / electricity / light even if the switching element 11 fails and the output is lowered due to an overcurrent state. It is desirable to add an output stop function of the control power supply by overcurrent (hereinafter referred to as OC) so as not to overload. However, in the case where the series connection body of switching elements does not have so-called element redundancy, the series connection body of switching elements causes collector overvoltage when all of the elements fail, so this stop by OC The meaning of adding functions is thin.

  The timing adjusters 61 to 6n are provided to correct on / off time differences caused by variations in characteristics of the switching elements 11 to 1n. By adjusting the timing adjusters 61 to 6n, application of an overvoltage to a specific element due to a switching time difference between the switching elements 11 to 1n is prevented. Note that a fine voltage imbalance that cannot be completely covered by the adjustment of the timing adjusters 61 to 6n can be minimized by providing a minimum individual snubber circuit (not shown). The timing adjusters 61 to 6n can be easily configured with delay elements. For example, the timing adjustment can be performed by making the resistance of a filter formed of a resistor / capacitor variable.

  If all the circuits described above are positive logic, the switching element can be turned on when the reference gate signal is Pon, and the switching element can be turned off when the reference gate signal is Poff.

  Each of the gate drive circuits 21 to 2n is mounted on a single substrate, and the substrate of the light distribution circuit 91 is closely mounted as a grandchild substrate of any one of the gate drive circuits 21 to 2n. Wiring can be minimized. In addition, regardless of whether or not the substrate of the light distribution circuit 91 is a grandchild substrate, the gate drive circuits 21 to 2n can be made common only by preparing connectors.

  Due to the above action, the number of optical fibers over a long distance can be reduced. Further, by fixing the potential of the light distribution circuit by light / electricity / light to the potential of the control power supply of the gate drive circuit of the switching element on the high potential side, the potential of the electric signal of the light distribution circuit can be stabilized. it can. Further, in the conventional method of directly distributing the light guide, when the series number of switching elements changes, there is a trouble that the LED light intensity of the low-voltage side control circuit must be adjusted together with the change of the light distribution circuit. In the first embodiment, since the electric buffer circuits 71 to 7n are provided and amplified again, it is possible to easily increase the number of optical transmitters for increasing the number of series.

  Hereinafter, a self-excited power conversion device according to a second embodiment of the present invention will be described with reference to FIGS. 3 and 4.

  FIG. 3 is a circuit configuration diagram of the self-excited power conversion device according to the second embodiment of the present invention. The same parts of the second embodiment as those of the self-excited power conversion device according to the first embodiment of the present invention shown in FIG. The second embodiment is different from the first embodiment in that the timing adjusters 61 to 6n provided on the output sides of the optical receivers 31 to 3n of the gate drive circuits 21 to 2n are replaced with the electric buffers of the optical distribution circuit 91, respectively. The configuration is such that each of the circuits 71 to 7n is provided on the output side.

  As in the case of the first embodiment, the timing adjustment means 61 to 6n, which are electric circuits, can be easily configured by delay elements. For example, the resistance of a filter formed of a resistor / capacitor is made a variable resistor. As a result, the timing can be adjusted.

  FIG. 4 is a circuit configuration diagram illustrating a state at the time of initial adjustment of voltage imbalance in the self-excited power conversion device according to the second embodiment of the present invention. As shown here, the light / electricity / light optical distribution circuit 91 is separated from the high-potential side housing 1 and moved to the low-potential side, the power supply Vin2 is connected to operate the optical distribution circuit 91, and the light The timing adjustment of the switching elements 11 to 1n connected in series can be performed on the low pressure side by replacing the guides 41 to 4n with light guides for testing.

  With the above action, it is not necessary to cut off the high voltage applied to the high potential side housing 1 every time timing adjustment is performed, and easy adjustment is possible. By reconnecting the light / electricity / light optical distribution circuit 91, which has been sufficiently adjusted in the adjustment step on the low-voltage side, to the gate drive circuit 21, the same effects as those described in the first embodiment can be obtained. Become.

  In the first and second embodiments, it is described that the voltage imbalance can be minimized with a minimum snubber circuit (not shown) if the timing is sufficiently adjusted by the timing adjusters 61 to 6n. However, by providing a voltage detection resistor, the collector voltage of each switching element is detected. When an overvoltage occurs, the gate voltage is controlled to provide a means for clamping the overvoltage at turn-off to a certain level. It is also possible to improve the balance.

DESCRIPTION OF SYMBOLS 1 ... High potential side housing | casing 11-1n ... Switching element 21-2n ... Gate drive circuit 30-3n ... Light receiving element 4, 41-4n ... Light guide (optical fiber)
50 to 5n: light emitting diodes 61 to 6n: timing adjustment circuits 71 to 7n: electric buffer circuits 81 to 8n: voltage amplification unit 91: optical distribution circuit

Claims (4)

A plurality of self-extinguishing semiconductor switching elements connected in series for simultaneous switching;
A plurality of gate driving circuits for driving each of the self-extinguishing semiconductor switching elements;
An optical transmission means for remotely supplying an on / off signal, which is a reference gate signal to be supplied to the gate drive circuit, by light isolation; and
An optical distribution circuit that receives the on / off signal transmitted by the optical transmission means and converts it into a first electric signal, distributes the first electric signal to each of the gate drive circuits, and converts it again into an optical signal. When,
A light guide for supplying each of the plurality of gate drive circuits with a pulse signal that is an output of each of the light distribution circuits,
Each of the gate drive circuits is
Receiving the pulse signal and converting it to a second electrical signal, and driving each of the plurality of self-extinguishing semiconductor switching elements via timing adjusting means for adjusting the on / off timing ;
A self-excited power characterized in that the light distribution circuit is mounted on a single substrate, and any one of the gate drive circuits is mounted on a single substrate, and the two substrates are placed in close contact with each other. Conversion device. A plurality of self-extinguishing semiconductor switching elements connected in series for simultaneous switching; a plurality of gate driving circuits for driving each of the self-extinguishing semiconductor switching elements;
An optical transmission means for remotely supplying an on / off signal, which is a reference gate signal to be supplied to the gate drive circuit, by light isolation; and
An optical distribution circuit that receives the on / off signal transmitted by the optical transmission means and converts it into a first electric signal, distributes the first electric signal to each of the gate drive circuits, and converts it again into an optical signal. When,
A light guide for supplying each of the plurality of gate drive circuits with a pulse signal that is an output of each of the light distribution circuits,
The light distribution circuit includes:
Have a timing adjusting means for adjusting the on-off timing of the first electrical signal the distribution,
A self-excited power characterized in that the light distribution circuit is mounted on a single substrate, and any one of the gate drive circuits is mounted on a single substrate, and the two substrates are placed in close contact with each other. Conversion device.   3. The voltage of the first electric signal is fixed by using a common control power source for the optical distribution circuit and a control power source for any one of the gate drive circuits. Self-excited power converter. A plurality of self-extinguishing semiconductor switching elements connected in series for simultaneous switching; a plurality of gate driving circuits for driving each of the self-extinguishing semiconductor switching elements;
An optical transmission means for remotely supplying an on / off signal, which is a reference gate signal to be supplied to the gate drive circuit, by light isolation; and
Timing for receiving the ON / OFF signal transmitted by the optical transmission means and converting it to a first electric signal, distributing the first electric signal to each of the plurality of gate driving circuits, and adjusting the ON / OFF timing, respectively. An optical distribution circuit which converts the light signal again through the adjusting means;
In the self-excited power conversion device including a light guide that supplies a pulse signal that is an output of each of the light distribution circuits to each of the plurality of gate drive circuits,
Move the light distribution circuit arranged in the high-potential side housing to the low-potential side, change the light guide to the adjustment light guide, connect the necessary control power supply, and operate the light distribution circuit A method for adjusting the gate timing of a self-excited power converter, wherein the timing adjusting means is adjusted.

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