JP3950263B2 - Motor drive power converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor drive power converter suitable for driving a traction motor in an electric vehicle, an electric scooter and an electric bicycle. SOLUTION: A power converter includes a serial circuit consisting of a plurality of power supplies which include at least a rechargeable power supply, a motor 2, a power converter 4 with an output terminal connected to the motor 2, a switch circuit 101 provided corresponding to one or both of input terminals of the power converter 4 and connected to the whole of the serial circuit of the power converter 4 or to a power supply as part of members in the serial circuit, and a plurality of filter capacitors in parallel with each power supply included in the serial circuit. The switch circuit 101 is normally put in such a state where the power converter 4 is connected to the serial circuit comprising power supplies. At regenerative time, the power converter 4 is switched by the switch circuit 101 and connected with the rechargeable power supply as part of the serial circuit.

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a motor drive power conversion device particularly suitable for driving a power motor such as an electric vehicle, an electric scooter, and an electric bicycle.
[0002]
[Prior art]
As a motor drive power converter for driving a power motor for electric vehicles, electric scooters, and electric bicycles, a battery and a capacitor are connected in series, and a power conversion circuit (first power converter) is connected from the battery and the capacitor. The power is supplied to the motor via the power, and the regenerative power from the motor is stored in the capacitor via the power converter and another power converter (second power converter). is there. For example, Japanese Patent Application Laid-Open No. 10-84628 and Japanese Patent Application Laid-Open No. 10-84601 introduce this type of motor drive power conversion device. These are technologies developed by the present applicant, but have been further developed and have achieved many results. FIG. 8 shows a motor drive power converter as an example of the recent results.
[0003]
In the figure, reference numeral 2 denotes a motor, and 4 denotes a power converter composed of, for example, an inverter whose output end is coupled to the motor 2. The power converter includes a bridge unit 6 and a smoothing capacitor 8 connected in parallel to the input end. The bridge unit 6 performs voltage conversion and forms a main part of the power converter 4. Further, the smoothing capacitor 8 absorbs ripples generated by high-speed switching in the bridge unit 6.
[0004]
Reference numeral 101 denotes a first switching circuit, whose common terminal is connected to the negative terminal of the input end of the power converter 4. Reference numeral 102 denotes a second switching circuit, the common terminal of which is connected to the plus terminal at the input end of the power converter 4. 12 is a rechargeable battery, 14 is a capacitor, and the battery 12 and the capacitor 14 are connected in series. Specifically, the cathode of the battery 12 is connected to the positive terminal of the capacitor 14. The negative terminal of the capacitor 14 is connected to the switching terminal A of the first switching circuit 101, the anode of the battery 12 is connected to the switching terminal D of the second switching circuit 102, and the first The switching terminal B of the switching circuit 101 and the switching terminal C of the second switching circuit 102 are both connected to the connection point between the battery 12 and the capacitor 14. Reference numeral 16 denotes a diode connected in parallel with the capacitor 14, which serves to prevent the voltage applied to the capacitor 14 from becoming reverse polarity and prevent its damage.
[0005]
In such a motor drive power conversion device, normally, the first switching circuit 101 is switched to the switching terminal A side and the second switching circuit 102 is switched to the switching terminal D side. Then, power running power is supplied from the battery 12 and the capacitor 14 to the motor 2 via the power conversion unit 4. During regeneration, the first switching circuit 101 is switched to the switching terminal A side, and the second switching circuit 102 is switched to the switching terminal C side. Then, regenerative power is supplied from the motor 2 to the capacitor 14 via the power conversion unit 4, and power is stored.
[0006]
When the regenerative state continues and the capacitor 14 is fully charged, the first switching circuit 101 is switched to the switching terminal B side, and the second switching circuit 102 is switched to the switching terminal D side. Then, the electric power from the motor 2 side is stored in the battery 12 by continuing the continuous regeneration state. Accordingly, since the regenerative power can be stored in the battery 12 even after the capacitor 14 is fully charged, the regenerative power storage capacity of the motor drive power converter can be increased.
Of course, it is not indispensable to regenerate power only in the battery 12. This is because the storage capacity of the regenerative power can be increased remarkably, but the regenerative power can be stored by the capacitor 14 without it.
[0007]
According to such a power conversion device for driving a motor, the capacitor 14 functions to supply a large amount of power to the motor 2 in a short time according to the load fluctuation of the motor 2, and the battery is averaged over a long time with a small amount of power. It fulfills the function of supplying electric power to the motor 2. Thereby, the peak load of the battery can be reduced, the life of the battery can be extended, and the power capacity can be substantially increased. It can be said that it is excellent in that respect.
[0008]
However, the motor driving power converter described above requires a precharge circuit for the switching circuits 101 and 102, and it is necessary to operate the precharge circuit in a predetermined sequence. This is because, when the switching state is instantaneously changed by the first switching circuit 101 and the second switching circuit 102, the inrush current due to the charge accumulated in the ripple absorbing smoothing capacitor 8 at the input end of the power converter 4 This is because it flows into the switching circuit 101 or 102 and burns out.
[0009]
Therefore, in practice, first and second switching circuits 101 and 102 are configured as shown in FIG. In the motor drive power converter shown in FIG. 9, the main current paths MA and MB of the first switch circuit 101 and the main current paths MC and MD of the second switch circuit 102 are configured by IGBT, Each of the precharge current paths PA, PB, PC, and PD is configured by an FET. RA, RB, RC, and RD are precharge resistors.
[0010]
In this embodiment, even if the MA, MB, MC, and MD switches are in the OFF state, regeneration to the battery 12 and the capacitor 14 is possible by the IGBT parasitic diodes that constitute the MA and MD switches.
When the MA switch is turned on, the MB switch is turned off, the MC switch is turned off, and the MD switch is turned on, the battery 12 and the capacitor 14 can be powered. Good.) By turning off the MB switch, turning on the MC switch, and turning off the MD switch, it is possible to regenerate only the capacitor 14, turning off the MA switch, turning off the MB switch. By turning on, turning off the MC switch, and turning off the MD switch (may be on), regeneration to only the battery becomes possible.
[0011]
[Problems to be solved by the invention]
By the way, according to the above-described power conversion device for driving a motor, since precharge is necessary to prevent inrush current from flowing through each switching circuit, a precharge switching element and a precharge resistor are required. Since it is necessary to operate the elements in a certain sequence, there is a problem that a control means for performing the sequence operation is required, the number of parts is increased, and the control circuit system needs to be complicated.
[0012]
Accordingly, an object of the present invention is to eliminate the need to precharge the switching circuit in a motor drive power converter in which the switching circuit switches the power source for accumulating regenerative power and supplying powering power from the motor side. There is.
[0013]
[Means for Solving the Problems]
As means for solving the above-mentioned problems, a motor drive power conversion device according to the invention of claim 1 includes a series circuit including a plurality of power supplies including at least one rechargeable power supply; a motor; Consists of a bridge part A power converter; this A switching circuit that is provided corresponding to one or both of the input ends of the power conversion unit, and that couples the power conversion unit to the whole of the series circuit or to a part of the power source constituting the series circuit; Between the switching circuit and the series circuit A plurality of smoothing capacitors provided in parallel with each power supply constituting the series circuit; A power converter having an output end coupled to the motor; The switching circuit is normally in a switching state in which the power conversion unit is coupled to the series circuit composed of the plurality of power sources, and the regenerative part of the power conversion unit constituting the series circuit is configured during regeneration. It is characterized in that the switching state is coupled to the power source.
[0014]
According to a second aspect of the present invention, in the motor drive power conversion device according to the first aspect, the switching circuit is constituted by a semiconductor element.
[0016]
Claim 3 A power conversion device for driving a motor according to the described invention includes a series circuit including two power supplies including at least one rechargeable power supply; and a plurality of power supplies provided in parallel to each power supply constituting the series circuit. A smoothing capacitor; a DC motor; and a switching circuit provided corresponding to each of the power supplies. Each switching circuit is formed by connecting a plurality of switching elements capable of high-speed switching in series. A diode connected in parallel so as to allow a current flowing in the opposite direction to the current flowing to each of the elements, and a DC circuit comprising the switching elements is connected in parallel to the corresponding power supply, The connection point is Flow Connected to different terminals of the motor. The plurality of switching elements are configured to perform a chopper operation. It is characterized by.
[0017]
Claim 4 A power conversion device for driving a motor according to the invention described above is a series circuit including three power supplies including at least one rechargeable power supply; and a plurality of power supplies provided in parallel to the power supplies constituting the series circuit. Smoothing capacitors; three first switching circuits provided corresponding to the respective power supplies; two second switching circuits connected to the first switching circuit; and connected to the second switching circuit The first switching circuit directly connects a plurality of switching elements. Column And a diode connected in parallel so as to allow a current in a direction opposite to the current flowing to each switching element, and a series circuit comprising the switching elements corresponds to the power source The second switching circuit is formed by connecting a plurality of switching elements in series, and in parallel so as to allow a current flowing in the opposite direction to the switching elements. A series circuit composed of switching elements of one second switching circuit includes a connection point of the first switching element of the first switching circuit and the first first switching circuit; Connected to the connection point of the switching element of the second first switching circuit adjacent to the second switching circuit; comprising the switching element of the other second switching circuit A column circuit is connected between the connection point of the second switching element of the second switching circuit and the connection point of the third switching element of the second switching circuit; A connection point is connected to different terminals of the DC motor; each switching element of at least one of the first switching circuit and the second switching circuit is composed of an element capable of high-speed switching. .
[0018]
Claim 5 The invention described in claims 1 to 4 In the motor drive power conversion device according to any one of the above, one of a plurality of power supplies constituting the DC circuit is an electric double layer capacitor.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a block diagram of a first embodiment of a motor drive power converter according to the present invention. In the figure, 2 is a motor, 4 is a power converter whose output end is coupled to the motor 2, and 6 is a bridge part which constitutes a main part thereof, and performs power conversion by high speed switching. Reference numeral 101 denotes a first switching circuit, the common terminal of which is connected to the negative terminal of the input end of the bridge section (power conversion section) 6. Reference numeral 102 denotes a second switching circuit, the common terminal of which is connected to the plus terminal at the input end of the bridge unit 6.
[0020]
81 is a first smoothing capacitor, 82 is a second smoothing capacitor, the two smoothing capacitors 81 and 82 are connected in series, and the negative side terminal of the first smoothing capacitor 81 is connected to the first switching circuit 101. Connected to the switching terminal A, the connection point of the first and second smoothing capacitors 81 and 82 is connected to the switching terminal B of the first switching circuit 101 and the switching terminal C of the second switching circuit 102, and the smoothing capacitor 82 is connected. Is connected to the switching terminal D of the second switching circuit 102.
[0021]
The power converter 4 includes a bridge section 6 constituting the main part, the two switching circuits 101 and 102, and the two smoothing capacitors 81 and 82, and is housed in a casing of one power converter. In FIG. 1, reference numeral 18 denotes this casing. That is, the casing 18 houses the bridge portion 6, the two switching circuits 101, 102, and the two smoothing capacitors 81, 82 that constitute the main part of the power converter 4. ing. Thus, not only the smoothing capacitors 81 and 82 are housed in the casing 18 of the power converter as a part of the power converter 4, but also the switching circuits 101 and 102 are housed in the casing 18, thereby Integration and miniaturization of the motor drive power conversion device including the converter 4 can be achieved.
[0022]
Reference numeral 12 denotes a battery, and reference numeral 14 denotes a capacitor, which is composed of, for example, an electric double layer capacitor and has a relatively large capacitance. The battery 12 and the capacitor 14 are connected in series. Specifically, the cathode of the battery 12 is connected to the positive terminal of the capacitor 14. The negative terminal of the capacitor 14 is connected to the switching terminal A of the first switching circuit 101, the anode of the battery 12 is connected to the switching terminal D of the second switching circuit 102, and the first The switching terminal B of the switching circuit 101 and the switching terminal C of the second switching circuit 102 are both connected to the connection point between the battery 12 and the capacitor 14. Reference numeral 16 denotes a diode connected in parallel with the capacitor 14, which serves to prevent the voltage applied to the capacitor 14 from becoming reverse polarity and prevent its damage. Although the inverter (power converter 4) has three phases in FIG. 1, it goes without saying that it may be a single phase.
[0023]
In such a motor drive power conversion device, normally, the first switching circuit 101 is switched to the switching terminal A side and the second switching circuit 102 is switched to the switching terminal D side. Then, power running power is supplied from the battery 12 and the capacitor 14 to the motor 2 via the power conversion unit 4. During regeneration, the first switching circuit 101 is switched to the switching terminal A side, and the second switching circuit 102 is switched to the switching terminal C side. Then, regenerative power is supplied from the motor 2 to the capacitor 14 via the power conversion unit 4, and power is stored.
[0024]
When the regenerative state continues and the capacitor 14 is fully charged, the first switching circuit 101 is switched to the switching terminal B side, and the second switching circuit 102 is switched to the switching terminal D side. Then, the regenerative power from the motor 2 side is stored in the battery 12 by continuing the continuous regeneration state. Accordingly, since the regenerative power can be stored in the battery 12 even after the capacitor 14 is fully charged, the regenerative power storage capacity of the motor drive power converter can be increased. Of course, it is not indispensable to regenerate power only in the battery 12. This is because the storage capacity of the regenerative power can be increased remarkably, but the regenerative power can be stored by the capacitor 14 without it.
[0025]
According to such a motor drive power conversion device, the first smoothing capacitor 81 is connected in parallel to the capacitor 14 constituting the series circuit, and the second smoothing capacitor 82 is connected in parallel to the battery 12 constituting the series circuit. The smoothing capacitors 81 and 82 are closer to the series circuit composed of the battery 12 and the capacitor 14 than the switching circuits 101 and 102 when viewed from the bridge unit 6 side forming the main part of the power converter 4. Regardless, the voltage of the capacitor 16 is applied to the first smoothing capacitor 81, and the voltage of the battery 14 is applied to the second smoothing capacitor 82. Therefore, it is not necessary to adjust the voltage by precharging at the time of switching.
[0026]
Therefore, unlike the motor drive power converter shown in FIG. 9, there is no need for precharge switching elements and precharge resistors, and there is no need to operate the switching elements in a certain sequence. No control means for performing the sequence operation is required. Therefore, the number of parts can be reduced and the control circuit system can be simplified.
[0027]
FIG. 2 is a block diagram of a second embodiment of the motor driving power converter of the present invention. In this embodiment, the switches of the current paths MA and MB of the first switching circuit 101 and the current paths MC and MD of the second switching circuit 102 are constituted by semiconductor elements, particularly insulated gate bipolar transistors (IGBT). DA, DB, DC, and DD are parasitic diodes inevitably parasitic on the IGBT forming the switches of the current paths MA, MB, MC, and MD.
In this embodiment, a transistor having a parasitic diode is used as a switching element. However, a transistor having no parasitic diode can also be used as a switching element. However, in that case, it is necessary to provide a diode outside the switching element and combine this diode with the switching element. In the case of the combination, it is necessary to connect the diode in parallel with the switching element so that the current in the direction opposite to the current flowing through the switching element flows.
[0028]
In the present embodiment, even if the MA, MB, MC, and MD switches are in the OFF state, regeneration to the battery 12 and the capacitor 14 is possible by the IGBT parasitic diodes that constitute the MA and MD switches. This is not a particularly essential route (mode).
[0029]
When the MA switch is turned on, the MB switch is turned off, the MC switch is turned off, and the MD switch is turned on, the battery 12 and the capacitor 14 can be powered. Good.) By turning off the MB switch, turning on the MC switch, and turning off the MD switch, it is possible to regenerate only the capacitor 12, turning off the MA switch, turning off the MB switch. By turning on, turning off the MC switch and turning off the MD switch (may be on), regeneration to only the battery 12 becomes possible. The switches constituting the switch circuit are not limited to IGBTs, but may be other semiconductor elements such as FETs (field effect transistors), and may be normal switches or relays that can switch current by on / off operation. Anything can be used.
[0030]
FIG. 3 is a block diagram of a third embodiment of the motor driving power converter of the present invention. In this embodiment, each semiconductor element constituting a switch constituting the switching circuits 101 and 102 in the second embodiment (however, in the second embodiment, it is an IGBT, but in this embodiment, an FET is used. In this embodiment, it goes without saying that an IGBT may be used instead of the FET.) The DC brush motor is rotated by operating as a chopper by switching at high speed. There are parasitic diodes DA, DB, DC, and DD in the FET as well as the IGBT.
[0031]
In this embodiment, there is nothing corresponding to the bridge portion 6 in the second embodiment, and the DC brush motor 21 is directly coupled to the switching circuits 101 and 102. If the inductance on the load side, that is, the DC brush motor 21 side is insufficient in the chopper operation, a choke coil or the like may be added to compensate for the inductance.
[0032]
4A shows the operation as a step-down chopper (high voltage side → low voltage side) of the switching circuit by the high-speed switching operation of the FET, and FIG. 4B shows the operation as a step-up chopper (high voltage side ← low voltage side). It is a circuit diagram explaining operation | movement. 4A and 4B, generally, a power source (battery) is connected to the high voltage side and a load (motor) is connected to the low voltage side. Specifically, FIG. 4A shows the operating state of an FET that is switched at high speed, for example, that forms a switch in the current path MD. When the FET is turned on, the current flows from the power source (high voltage side) to the motor (low voltage). The current is stored by the inductance of the motor (and choke coil). When the FET is off, the stored current flows through the parasitic diode of another FET. FIG. 4B shows the operating state of the FET in the current path MC that is switched at high speed. When the FET is turned on, a current flows through the motor (and the choke coil), and the current is stored by the inductance. When the FET is turned off, the stored current flows through the parasitic diode of another FET toward the power supply (high voltage side).
[0033]
5A to 5C are circuit diagrams for explaining the operation of the power converter shown in FIG. 3 in three different powering modes, and FIG. 5A is a high-speed switching only of the FET in the current path MA. The operation in the power running mode in which the power running power is supplied only from the capacitor 14 will be described. That is, in this power running mode, the MB, MC, and MD FETs are all turned off, and only the MA FET is switched at high speed. In this configuration, a step-down chopper having the capacitor 14 on the high voltage side and the DC brush motor 21 on the low voltage side is formed by the MA FET, the parasitic FET DB of the MB FET, and the inductance of the DC brush motor 21. Accordingly, the power running current is supplied to the motor 21 only from the capacitor 14.
[0034]
FIG. 5B shows an operation in the power running mode in which only the FET of the current path MD is switched at high speed and power running power is supplied to the motor 21 only from the battery 12. That is, in this power running mode, the MA, MB, and MC FETs are all turned off, and only the MD FET is switched at high speed. In this configuration, a step-down chopper having the battery 12 on the high voltage side and the DC brush motor 21 on the low voltage side is formed by the MD FET, the parasitic FET DC of the MC FET, and the inductance of the DC brush motor 21. Accordingly, the power running current is supplied to the motor 21 only from the battery 12.
[0035]
FIG. 5C shows an operation in a power running mode in which both FETs in the current paths MA and MD perform high-speed switching operation in synchronization with each other and power running power is supplied to the motor 21 from both the battery 12 and the capacitor 14. . That is, in this power running mode, the MA and MD FETs are switched at high speed. In this configuration, the parasitic circuit DB DB and DC of both the MA and MD FETs, the MB and MC FETs, and the inductance of the DC brush motor 21 make the series circuit of the battery 12 and the capacitor 14 the high voltage side and the DC brush motor 21. A step-down chopper on the low voltage side is formed.
[0036]
FIGS. 6A to 6C are circuit diagrams for explaining the operation of the power converter shown in FIG. 3 in three different regeneration modes. FIG. 6A shows the FET of the current path MC turned on. The operation in the regenerative mode in which regenerative power is supplied only to the capacitor 14 by switching the FET of MB at high speed as it is is shown. That is, in this regeneration mode, the MC FET is kept on and only the MB FET is switched at high speed. In this configuration, a step-up chopper with the capacitor 14 on the high voltage side and the DC brush motor 21 on the low voltage side is formed by the MB FET, the MA FET parasitic diode DA, and the inductance of the DC brush motor 21. Therefore, the regenerative power from the motor 21 is regenerated only to the capacitor 14.
[0037]
FIG. 6B shows the operation in the regenerative mode in which the regenerative power from the motor 21 is supplied only to the battery 12 by switching the MC FET at high speed with the FET of the current path MB turned on. That is, in this regeneration mode, the MB FET is kept on and only the MC FET is switched at high speed. In this configuration, a step-up chopper having the battery 12 on the high voltage side and the DC brush motor 21 on the low voltage side is formed by the MC FET, the parasitic FET DD of the MD FET, and the inductance of the DC brush motor 21. Therefore, only the battery 12 is regenerated.
[0038]
FIG. 6C shows an operation in a regenerative mode in which regenerative power from the motor 21 is supplied to both the battery 12 and the capacitor 14 by simultaneously switching MB and MC FETs simultaneously and at high speed. That is, in this regeneration mode, the MB and MC FETs are switched at high speed. In this configuration, both the MB and MC FETs, the parasitic diodes MA and MD of the FETs of MA and MD, and the inductance of the DC brush motor 21 make the DC circuit of the battery 12 and the capacitor 14 the high voltage side and the DC brush motor 21. A step-up chopper on the low voltage side is formed. Therefore, regenerative power from the motor 21 is supplied to both the battery 12 and the capacitor 14.
[0039]
As described above, according to this embodiment, powering by a capacitor, powering by a battery, powering by both a capacitor and a battery, regeneration to a capacitor, regeneration to a battery, regeneration to both a capacitor and a battery are possible. become.
Then, the switching circuits 101 and 102 appropriately perform high-speed switching, control such as ON continuation, and the like, and also play a role of power conversion in the power running and regeneration modes by boosting and stepping down. Therefore, since the switching circuit also serves as a power converter, a bridge for power conversion is not required, the configuration of the power converter for driving the motor can be greatly simplified, and downsizing and cost reduction can be realized. Can do.
[0040]
FIG. 7 is a block diagram of a fourth embodiment of the motor driving power converter of the present invention. In this embodiment, the number of power supplies, which was two in the third embodiment, is changed to three.
In the figure, 32, 34, and 36 are power supplies connected in series, and at least one of them can be charged. Reference numerals 81, 82, and 83 denote smoothing capacitors connected in parallel to the respective power supplies 32, 34, and 36. Reference numerals 101, 102, and 103 denote first switching circuits, respectively, for switching the second embodiment of the present invention shown in FIG. The configuration is substantially the same as the circuits 101 and 102 (however, the switching element is an IGBT in the second embodiment, but an FET in the present embodiment). The first switching circuit is provided corresponding to the power source. In the present embodiment, the number of power sources is three, so the number is three.
[0041]
Reference numerals 201 and 202 denote second switching circuits, which are provided between the first switching circuits 101, 102, and 103 and the DC brush motor 21. The second switching circuits 201 and 202 have the same configuration as the first switching circuits 101, 102, and 103 in this embodiment. The first switching circuit 201 of the second switching circuits 201 and 202 includes the switching element connection point of the first one of the first switching circuits 101, 102 and 103, and the second The switching element connection point of the object 102 is connected.
[0042]
The second switching circuit 202 of the second switching circuits 201 and 202 includes a switching element connection point of the second one of the first switching circuits 101, 102, and 103, and a third one. It is connected between the switching element connection points of the thing 103. The switching element connection points of the second switching circuits 201 and 202 are connected to different terminals of the motor 21.
[0043]
Then, the first switching circuits 101, 102, 103 are caused to perform a path switching operation similar to the switching circuits 101, 102 of the second embodiment shown in FIG. 2, for example, and the second switching circuits 201, 202 are shown in FIG. Similarly to the switching circuits 101 and 102 of the third embodiment, the path switching operation and the voltage adjustment (step-up / step-down) operation by high-speed switching of the switching element are performed. The voltage adjustment may be performed not by the second switching circuits 201 and 202 but by the first switching circuits 101, 102, and 103.
[0044]
According to the present embodiment, it is possible to increase the power source for power running and regeneration, and the combination thereof, and the power storage capacity can be further increased.
Note that the number of power supplies can be increased from three. For example, when the number of power supplies is four, four first switching circuits, three second switching circuits, and two third switching circuits are required, and the first, The second and third switching circuits are interposed.
[0045]
In each of the third and fourth embodiments, it is not essential that the motor is a direct current brush motor. For example, a piezoelectric motor or the like can be used.
In each of the above embodiments, the battery 12 and the capacitor 14 are used as power sources. However, if at least one of a plurality of power sources connected in series is a DC power source and can be charged (regenerated), the power source The type may be a battery, a capacitor, a solar cell, a fuel cell, or a DC generator.
[0046]
[Effects of the invention]
As described above, according to the motor drive power conversion device of the present invention, in the motor drive power conversion device in which the power source for regeneration and power running is switched by the switching circuit, the ripple generated by the power supply conversion unit is reduced. Since the smoothing capacitor to absorb is provided on the series circuit side of the power supply from the switching circuit, the voltage on the power supply side is applied to the smoothing capacitor regardless of the operation on the switching circuit side, and the applied voltage is applied to the smoothing capacitor due to the instantaneous change of the switching state. There is no fear of joining. Therefore, it is not necessary to adjust the voltage by precharging at the time of switching, no precharging switching element and precharging resistor are required, and no control means for operating the switching element in a certain sequence is required. The number of control circuits can be reduced, and the configuration of the control circuit system can be simplified.
[0047]
When the switching circuit for switching the power source for power running or regeneration is boosted or stepped down by high-speed switching so as to function as a power converter, the switching circuit serves as a power converter. As a result, a bridge for power conversion is not required, the configuration of the power converter for driving the motor can be greatly simplified, and downsizing and cost reduction can be realized.
[Brief description of the drawings]
FIG. 1 is a block diagram of a first embodiment of a power conversion apparatus for driving a motor according to the present invention.
2 shows a second example of the motor drive power conversion device of the present invention in which the switch circuit of the motor drive power conversion device shown in FIG. 1 is configured by a semiconductor element, particularly an IGBT (insulated gate bipolar transistor). It is a block diagram of an Example.
FIG. 3 is a block diagram of a third embodiment of the motor driving power converter of the present invention.
4A is a circuit diagram illustrating an operation as a step-down chopper of a switching circuit by a high-speed switching operation of an FET, and FIG. 4B is a circuit diagram illustrating an operation as a step-up chopper.
FIGS. 5A to 5C are circuit diagrams illustrating the operation of each powering mode of the motor drive power conversion device of FIG. 3;
6A to 6C are circuit diagrams for explaining the operation of different regeneration modes of the motor-driven power conversion device of FIG. 3;
FIG. 7 is a block diagram of a fourth embodiment of the power conversion apparatus for driving a motor according to the present invention.
FIG. 8 is a block diagram for explaining the principle of one conventional example of a power converter for driving a motor.
9 is a block diagram showing a specific configuration example of the conventional example shown in FIG. 8 of the power conversion device for driving a motor.
[Explanation of symbols]
2, 21 Motor
4 Power converter
6 Bridge part
81, 82 Smoothing capacitor
101, 102, 103, 201, 202 switching circuit
12 Power supply (battery)
14 Power supply (capacitor)
16 Capacitor protection diode
18 Power converter housing

Claims (5)

A series circuit composed of a plurality of power supplies including at least one rechargeable power supply;
A motor,
A power conversion unit comprising a bridge unit, provided in correspondence to one or both of the input terminals of the power converting unit, a part of the power conversion unit constituting the binding the whole or a series circuit of the series circuit a switching circuit for coupling to a power source, and a plurality of smoothing capacitor provided in parallel with each power constituting the series circuit between the該切circuit and the series circuit, the output end to the motor A combined power converter, and
The switching circuit is normally in a switching state in which the power conversion unit is coupled to the series circuit including the plurality of power supplies, and the power conversion unit is coupled to a part of the rechargeable power source constituting the series circuit during regeneration. A power conversion device for driving a motor, characterized by being configured to be in a switching state.   2. The motor drive power converter according to claim 1, wherein the switching circuit is constituted by a semiconductor element. A series circuit composed of two power sources including at least one rechargeable power source;
A plurality of smoothing capacitors provided in parallel with each power supply constituting the series circuit;
A DC motor;
And a switching circuit provided corresponding to each power source,
Each switching circuit is formed by connecting a plurality of switching elements capable of high-speed switching in series, and further diodes connected in parallel so as to allow currents flowing in the opposite direction to the respective switching elements. has its DC circuit consisting of a switching element is connected in parallel to said power supply corresponding connection point of the switching element is connected to different terminals of the dc motor,
The power conversion device for driving a motor, wherein the plurality of switching elements are configured to perform a chopper operation . A series circuit composed of three power supplies including at least one rechargeable power supply;
A plurality of smoothing capacitors provided in parallel with each of the power supplies constituting the series circuit;
Three first switching circuits provided corresponding to the power sources;
Two second switching circuits connected to the first switching circuit;
A DC motor connected to the second switching circuit,
Said first switching circuit, each constituted by connecting a plurality of switching elements in series, are further connected in parallel to as respectively to permit a current in the opposite direction of the current flowing to it against its respective switching elements diodes A series circuit comprising the switching elements is connected in parallel to the corresponding power source;
Each of the second switching circuits includes a plurality of switching elements connected in series, and each of the switching elements has a diode connected in parallel so as to allow a current in a direction opposite to a current flowing therethrough. And
A series circuit consisting of switching elements of one second switching circuit includes a connection point of the first switching element of said first switching circuit, of the second adjacent to said first first switching circuit of the Connected to the connection point of the switching element of one switching circuit,
A series circuit consisting of the switching elements of the second switching circuit of the other, a connection point of the second switching element of said second switching circuit, is also connected between the connection point of the third switching element ,
The connection point of the switching elements of each of the second switching circuits is connected to different terminals of the DC motor,
The motor drive power conversion device, wherein each switching element of at least one switching circuit of each of the first switching circuits and each of the second switching circuits is an element capable of high-speed switching.   The motor drive power conversion device according to any one of claims 1 to 4, wherein one of a plurality of power sources constituting the DC circuit is an electric double layer capacitor.

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