JP2013090511A - Power control unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power control unit used for an AC load having a charging function and capable of supplying power efficiently to a secondary battery.SOLUTION: Partial circuit of a charging circuit 33 and a three-phase rotary motor 11 is shared. Switching arms 21-24 constituting the circuit thus shared include a second switching arm 23 which functions both when the three-phase rotary motor 11 is driven and when the voltage is boosted in order to charge a secondary battery 12. A second drive circuit 60 for driving the second switching arm 23 is configured so that the on time of a high side arm element 23a of the second switching arm 23 is longer than the on time by a first drive circuit 50.

Description

  The present invention relates to a power control apparatus that performs power feeding from a secondary battery to an AC load and charging of the secondary battery from a charging power source.

  Patent Document 1 discloses that a charging device is configured using windings of an AC motor. Patent Document 2 discloses that a charging reactor is added between an AC power supply for charging and a three-phase inverter circuit to constitute a boosting power conversion circuit for charging.

JP 2010-45961 A JP 2007-195336 A

  In the prior art described in Patent Literatures 1 and 2, an electric motor such as an AC motor is configured to have the function of a charging device. When the electric motor has the function of the charging device as described above, a part of the circuit of the charging device and the electric motor is shared to simplify the configuration. However, if the circuit is simply shared, there is a problem that the switching operation of the switching means is restricted and charging cannot be performed efficiently.

  Accordingly, the present invention has been made in view of the above-described problems, and an object thereof is to provide a power control device that can be used for an AC load having a charging function and can efficiently supply power to a secondary battery. And

  The present invention employs the following technical means in order to achieve the aforementioned object.

In invention of Claim 1, a secondary battery (12),
AC load (11) operated by AC power;
A charging unit (33) for converting AC power from the AC power source (14) to DC power and supplying the secondary battery to charge the secondary battery,
A part of the circuit is shared between the charging part and the AC load.
The shared circuit includes a plurality of switching means (21 to 23) and drive circuits (50, 60) for individually driving the switching means,
The plurality of switching means include a common switching means that functions both when driving an AC load and when boosting to charge a secondary battery,
In the shared drive circuit (60) for driving the shared switching means (23), the ON time of the shared switching means is longer than the ON time of the other switching means by the other drive circuit (50). The power control apparatus is configured.

  According to the first aspect of the present invention, a part of the circuit is shared between the charging unit and the AC load. The plurality of switching means constituting the shared circuit include shared switching means that function both when driving an AC load and when boosting the secondary battery for charging. The shared drive circuit for driving the shared switching means is configured such that the ON time of the shared switching means is longer than the ON time of the other switching means by other drive circuits. By extending the ON time of the shared switching means, the time for charging the secondary battery can be extended. In the existing drive circuit, there is a problem that sufficient charging cannot be performed due to the restriction of the ON time of the switching means. However, in the present invention, the restriction of the switching means can be reduced. As a result, power can be efficiently supplied to the secondary battery.

  According to a second aspect of the present invention, the shared drive circuit includes a power supply (61) for supplying electric power for turning on the shared switching means.

  According to the second aspect of the present invention, the shared drive circuit includes a power source that supplies power for turning on the shared switching means. Therefore, on / off of the shared switching means can be controlled. As a result, the secondary battery can be charged more efficiently.

Furthermore, in the invention according to claim 3, each drive circuit includes a bootstrap circuit (50),
In the bootstrap circuit in the shared drive circuit, the capacity of the bootstrap capacitor (51) and the current capacity of the bootstrap diode (54) are larger than the bootstrap capacitors and diodes in the other drive circuits. It is characterized by that.

  According to the third aspect of the present invention, the bootstrap circuit in the shared drive circuit has a larger capacity of the bootstrap capacitor and a current allowable amount of the bootstrap diode than other drive circuits. Therefore, the shared switching means can be turned on for a longer time by the bootstrap circuit in the shared drive circuit. Therefore, power can be efficiently supplied to the secondary battery.

  Furthermore, the invention according to claim 4 is characterized in that the plurality of switching means are modularized.

  According to the invention of claim 4, the plurality of switch means are modularized. Thereby, the configuration can be simplified.

  In addition, the code | symbol in the bracket | parenthesis of each above-mentioned means is an example which shows a corresponding relationship with the specific means as described in embodiment mentioned later.

1 is a block diagram illustrating a power control apparatus 10 according to a first embodiment. It is a block diagram which shows the relay state when charging the secondary battery. 3 is an enlarged block diagram showing a first switching arm 21. FIG. It is a block diagram which expands and shows a part of electric power control apparatus 10 shown in FIG. It is the circuit diagram which modularized the switching arms 21-24. FIG. 6 is a circuit diagram showing a second drive circuit 60A.

  Hereinafter, a plurality of embodiments for carrying out the present invention will be described with reference to the drawings. In some embodiments, portions corresponding to the matters described in the preceding embodiments may be given the same reference numerals, or one letter may be added to the preceding reference numerals, and overlapping descriptions may be omitted. In addition, when a part of the configuration is described in each embodiment, the other parts of the configuration are the same as those of the embodiment described in advance. In addition to the combination of parts specifically described in each embodiment, the embodiments may be partially combined as long as the combination does not hinder the combination.

(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram showing a power control apparatus 10 according to a first embodiment to which the present invention is applied. FIG. 2 is a block diagram illustrating another relay state of the power control apparatus 10. FIG. 1 shows a relay state when the three-phase rotary motor 11 is driven. FIG. 2 shows a relay state when the secondary battery 12 is charged.

  The power control apparatus 10 includes a secondary battery 12 that is mounted on a vehicle and supplies DC power. The secondary battery 12 is a rechargeable battery, for example, a lithium ion battery. The rated voltage of the secondary battery 12 is, for example, 200V.

  The power control apparatus 10 includes an inverter circuit 13 that converts DC power supplied from the secondary battery 12 into AC power. The inverter circuit 13 includes a plurality of switching arms 21 to 23. In this embodiment, three switching arms 21 to 23 are provided. The inverter circuit 13 is a three-phase power conversion circuit. Each of the switching arms 21 to 23 includes a high-side arm element 21a to 23a and a low-side arm element 21b to 23b connected in series. Each arm element 21a-23a, 21b-23b is an IGBT (insulated gate bipolar transistor) element. Each of the arm elements 21a to 23a and 21b to 23b can be represented by a transistor element and a reverse diode connected in parallel to the transistor element. Each of the switching arms 21 to 23 has a DC input / output terminal at both ends, and has an AC input / output terminal between the low-side arm elements 21b to 23b and the high-side arm elements 21a to 23a. The switching arms 21 to 23 are arranged in parallel with each other. The inverter circuit 13 is an AC-DC power conversion circuit capable of orthogonal bidirectional power conversion.

  The power control apparatus 10 includes a three-phase rotary motor 11 that operates with AC power supplied from the inverter circuit 13. The three-phase rotating motor 11 is an auxiliary motor for driving an auxiliary machine such as a compressor mounted on a vehicle. The three-phase rotary motor 11 is also called a multiphase AC load.

  The power control device 10 is connected to an AC power supply 14 that supplies AC power for charging the secondary battery 12. The AC power supply 14 is also called an external power supply. AC power supply 14 supplies AC power having a maximum voltage value Vacmax higher than, for example, rated voltage VB of secondary battery 12. For example, the AC power supply 14 supplies Vrms 200 V, and the maximum voltage value Vacmax is about 282 V. The AC power supply may be a commercial Vrms 100V. The AC power supply 14 supplies single-phase AC power. The AC power supply 14 is a commercial power supply supplied from a local distribution network or a private power supply supplied from a generator installed in a house or the like.

  The power control device 10 and the AC power supply 14 are connected via an input filter 15. The input filter 15 includes a socket or a plug, and is configured to be intermittent by a user. When the user connects the AC power supply 14 to the input filter 15, the power control device 10 enters a charging mode in which the secondary battery 12 is charged from the AC power supply 14. The AC power supply 14 is connected only to some of the switching arms 21 and 22 among the three switching arms 21 to 23 of the inverter circuit 13. The part of the switching arms 21 and 22 includes two first switching arms 21 and 22.

  The power control apparatus 10 includes a first power conversion circuit 31 configured to include first switching arms 21 and 22 that constitute a part of the inverter circuit 13. The first power conversion circuit 31 includes first switching arms 21 and 22 that constitute a part of the inverter circuit 13. The first power conversion circuit 31 is an AC / DC bidirectional power conversion circuit that converts AC power supplied from the AC power supply 14 into DC power. The first power conversion circuit 31 can also be called an AC-DC power conversion circuit or a rectifier circuit. The first power conversion circuit 31 outputs an output voltage Vr that has been full-wave rectified.

  The power control apparatus 10 includes a third switching arm 24 that does not belong to the inverter circuit 13. The third switching arm 24 includes a high-side arm element 24a and a low-side arm element 24b connected in series. A reactor 25 is provided between the second switching arm 23 and the third switching arm 24. The second switching arm 23, the third switching arm 24, and the reactor 25 constitute a second power conversion circuit 32. The second power conversion circuit 32 is an H-bridge step-up / step-down chopper circuit. The second switching arm 23 provides a step-up type switching arm for the reactor 25. The third switching arm 24 provides a step-down switching arm for the reactor 25. The second power conversion circuit 32 boosts or steps down the DC power supplied from the first power conversion circuit 31. The second power conversion circuit 32 can also be referred to as a converter circuit capable of stepping up or down a voltage, or a DC-DC power conversion circuit capable of converting DC power.

  The power control device 10 includes a smoothing capacitor 26. The smoothing capacitor 26 is provided between the secondary battery 12 and the second power conversion circuit 32. The smoothing capacitor 26 becomes an input capacitor connected in parallel between the DC terminals of the second power conversion circuit 32 in the drive mode. On the other hand, in the charging mode, the smoothing capacitor 26 is an output capacitor that smoothes the output of the second power conversion circuit 32 serving as a boost chopper circuit.

  The power control apparatus 10 includes a plurality of relays 41 and 42. The plurality of relays 41 and 42 provide circuit switching means for switching the connection state among the secondary battery 12, the plurality of switching arms 21 to 24, the three-phase rotary motor 11, and the AC power supply 14. The circuit switching means is configured to change the connection state between the secondary battery 12 and the three-phase rotary motor 11, the connection state in which the inverter circuit 13 is configured, and the first power between the AC power source 14 and the secondary battery 12. It switches to the connection state in which the charging circuit (charging part) 33 containing the conversion circuit 31 and the 2nd power conversion circuit 32 is comprised. The circuit switching means includes a secondary battery 12 and a plurality of switching arms 21 so as to constitute an inverter circuit 13 that feeds power from the secondary battery 12 to the three-phase rotating motor 11 in the drive mode in which the AC power supply 14 is not connected. To 24 and the three-phase rotary electric motor 11 are connected. Further, the circuit switching means configures the first power conversion circuit 31 and the second power conversion circuit 32 that charge the secondary battery 12 from the AC power supply 14 in the charging mode in which the AC power supply 14 is connected. The secondary battery 12, the plurality of switching arms 21 to 24, and the AC power source 14 are connected.

  The load relay 41 includes a first switch 41 a and a second switch 41 b provided between the three-phase rotary motor 11 and the inverter circuit 13. The load relay 41 opens and closes a circuit so as to switch between a driving mode in which the secondary battery 12 drives the three-phase rotary motor 11 and a charging mode in which the secondary battery 12 is charged by the AC power supply 14. The state shown in FIG. 2 is a charging mode, and the load relay 41 is open. In the drive mode shown in FIG. 1, the load relay 41 is closed. The load relay 41 includes a switch only in two phases (U phase and W phase) of the three-phase rotary electric motor 11, and does not include a switch in the remaining one phase (V phase).

  The second switch 41 b is connected to the second switching arm 23 that constitutes the second power conversion circuit 32. Therefore, the second switching arm 23 constituting the second power conversion circuit 32 and the three-phase rotary motor 11 are closed when the secondary battery 12 supplies power to the three-phase AC electric machine, and the AC power supply 14 A second switch 41b that is opened when the secondary battery 12 is charged is provided. According to this configuration, when the second switching arm 23 is used as the second power conversion circuit 32 of the charging circuit 33, the second switch 41b is opened. For this reason, it is possible to prevent noise accompanying switching of the second switching arm 23 from being transmitted to the three-phase rotary electric motor 11.

  The switching relay 42 includes a third switch 42 a provided between the positive terminal of the secondary battery 12 and the positive DC terminal of the inverter circuit 13, the positive terminal of the secondary battery 12, and the AC terminal of the second switching arm 23. And a fourth switch 42b provided between them. The third switch 42 a is provided closer to the inverter circuit 13 than the connection between the secondary battery 12 and the reactor 25. The fourth switch 42 b is connected in series with the reactor 25. The switching relay 42 opens and closes the circuit so as to switch between the driving mode and the charging mode. In the drive mode, as shown in FIG. 1, the third switch 42a is closed and the fourth switch 42b is opened. In the charging mode, as shown in FIG. 2, the third switch 42a is opened and the fourth switch 42b is closed. In the charging mode, the circuit can be opened and closed so as to switch between the step-up mode and the step-down mode.

  The power control device 10 includes a control device 80. The control device 80 controls the arm elements 21a to 24a and 21b to 24b and the relays 41 and 42 that constitute the switching arm. The power control device 10 includes a current sensor (not shown) that detects an AC current Iac supplied from the AC power supply 14, a voltage sensor (not shown) that detects an AC voltage Vac supplied from the AC power supply 14, A voltage sensor (not shown) for detecting the voltage VB of the secondary battery 12. The control device 80 and the plurality of sensors constitute a control system of the power control device 10.

  The control device 80 is provided by a microcomputer provided with a computer-readable storage medium. The storage medium stores a computer-readable program. The storage medium can be provided by a memory.

  When in the charging mode, the control device 80 opens the third switch 42a and closes the fourth switch 42b as shown in FIG. The control device 80 controls the first switching arms 21 and 22 so that the AC voltage Vac is full-wave rectified and the output voltage Vr is supplied. The control device 80 controls the second switching arm 23 and the third switching arm 24 so as to convert the output voltage Vr into a voltage for charging the secondary battery 12, for example, a voltage VB. As a result, when Vr <VB, the second power conversion circuit 32 is controlled as a step-up chopper circuit, and when Vr> VB, the second power conversion circuit 32 is controlled as a step-down chopper circuit.

  FIG. 3 is an enlarged block diagram showing a part of the power control apparatus 10 shown in FIG. In FIG. 3, a drive circuit 50 that is not shown in FIG. 1 is additionally shown. The drive circuit 50 is individually provided in all the switching arms 21 to 23 constituting the inverter circuit 13. The drive circuit shown in FIG. 3 is a first drive circuit 50 provided in the first switching arms 21 and 22.

  The first drive circuit 50 is a bootstrap circuit, and includes a drive capacitor 51, a drive IC (Integrated Circuit) 52, a drive resistor 53, a drive diode 54, and a drive power supply 55. The bootstrap circuit is a circuit that can generate a positive voltage necessary for driving the switching element on the high side. The first drive circuit 50 charges the drive capacitor 51 and drives the drive IC 52 to switch the high-side arm element. And in order to charge, the low side arm element is turned ON and the path | route shown by the arrow in FIG. 3 is made. Here, the drive diode 54 is a diode that prevents current from flowing in the reverse direction. The drive resistor 53 is a resistor for adjusting the current flowing through the drive capacitor 51. The drive power supply 55 is a power supply for charging the drive capacitor 51.

  FIG. 4 is an enlarged block diagram showing a part of the power control apparatus 10 shown in FIG. In FIG. 3, a drive circuit 60 that is not shown in FIG. 1 is additionally shown. A drive circuit 60 shown in FIG. 4 is a second drive circuit 60 provided in the second switching arm 23.

  The second drive circuit 60 has an insulated power supply 61 as a power supply so that the high-side arm element 23a of the second switching arm 23 can be always turned on. In other words, among the switching means shared for the three-phase rotating motor 11 and for charging, the drive IC 62 for operating the high-side arm element 23a of the second switching arm 23 is switched using the insulated power supply 61. A power supply for making an ON / OFF signal used for the power supply is supplied. Accordingly, the first drive circuit 50 shown in FIG. 3 requires a period for turning on the low-side arm element of FIG. 3 in order to perform bootstrap charging, whereas the second drive circuit 60 shown in FIG. Then, the high-side arm element 23a can always be turned on without turning on the low-side arm element 23b. Therefore, charging can be performed efficiently without being restricted by switching means such as arm elements, and charging with boosting can be performed.

  FIG. 5 is a circuit diagram showing an example in which the switching arms 21 to 24 constituting the power control device 10 are modularized. As shown in FIG. 5, the switching arms 21 to 24 constituting the power control device 10 can be used as a module to constitute an element that can simultaneously drive the three-phase rotary motor 11 and charge the secondary battery 12. Here, modularization means that semiconductor elements such as the switching arms 21 to 24 are packaged into one. Therefore, handling becomes easier than modularization and handling individually.

  Since the switching arms 21 to 24 generate heat, it is necessary to cool them. However, since the elements that generate heat are modularized, the switching arms 21 to 24 can be cooled by cooling the modules. . As a result, the cooling locations can be gathered, so that the cooling efficiency can be improved.

  As described above, a part of the circuit is shared by the charging unit and the three-phase rotating motor 11 of the present embodiment. The switching arms 21 to 24, which are a plurality of switching means constituting a shared circuit, are used in both cases of driving the three-phase rotary motor 11 and boosting the secondary battery 12 for charging. A second switching arm 23 is included as a functioning shared switching means. In the second drive circuit 60 that is a shared drive circuit for driving the second switching arm 23, the on time of the high-side arm element 23 a of the second switching arm 23 is longer than the on time of the first drive circuit 50. It is configured to be long. By increasing the ON time of the second switching arm 23, the time for charging the secondary battery 12 can be increased. In the existing drive circuit, there is a problem that sufficient charging cannot be performed due to the restriction of the on-time of the second switching arm 23. However, in this embodiment, the restriction of the second switching arm 23 can be reduced. As a result, power can be efficiently supplied to the secondary battery 12.

  In the present embodiment, the second drive circuit 60 includes an insulated power supply 61 that supplies power for turning on the second switching arm 23. Therefore, on / off of the second switching arm 23 can be controlled. As a result, the secondary battery 12 can be charged more efficiently.

  Furthermore, in this embodiment, the plurality of switching arms are modularized. Thereby, the configuration can be simplified.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 6 is a circuit diagram showing the second drive circuit 60A. The present embodiment is characterized in that the configuration of the second drive circuit 60A is different from that of the first embodiment.

  In the second drive circuit 60 </ b> A of the present embodiment, the insulated power supply 61 is constituted by the insulated transformer 70. A switching element (not shown) is provided on the primary side of the insulating transformer 70. The switching element accumulates energy on the primary side of the transformer when the switching element is on, and rectifies the energy released from the secondary winding when the switching element is off. And half-wave rectification by the smoothing capacitor 72. Thereby, on / off of the second switching arm 23 can be controlled. Therefore, similarly to the first embodiment described above, the secondary battery 12 can be charged more efficiently.

(Other embodiments)
The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  The structure of the said embodiment is an illustration to the last, Comprising: The scope of the present invention is not limited to the range of these description. The scope of the present invention is indicated by the description of the scope of claims, and further includes meanings equivalent to the description of the scope of claims and all modifications within the scope.

  In the first embodiment described above, the second drive circuit 60 is configured to use the insulated power supply 61, but is not limited to such a configuration. For example, the second drive circuit 60 is the same as the first drive circuit 50. You may comprise. In this case, the set value of each element is adjusted so that the ON time of the high-side arm element is longer than that of the first drive circuit 50. Specifically, the current capacity of the drive capacitor 51 and the drive diode can be charged in a short time by using an element having a value larger than that of the first drive circuit 50, or the power consumption of the drive IC is reduced. Or change it to something. As a result, unlike the second drive circuit 60 of the first embodiment, the high-side arm element cannot always be turned on, but the on-period of the high-side arm element can be increased. It is possible to reduce.

  Further, for example, the three-phase rotary electric motor 11 may be a main power motor as a driving power source for the vehicle. The three-phase rotary motor 11 may be a generator motor that can also function as a generator in addition to the function as a motor.

DESCRIPTION OF SYMBOLS 10 ... Electric power control apparatus 11 ... Three-phase rotary motor (AC load)
12 ... Secondary battery 14 ... AC power supply 22 ... First switching arm (switching means)
23 ... 2nd switching arm (common switching means)
24. Third switching arm (switching means)
25 ... Reactor 26 ... Smoothing capacitor 33 ... Charging circuit (charging unit)
50 ... 1st drive circuit (other drive circuit, bootstrap circuit)
51 ... Drive capacitor (bootstrap capacitor)
54 ... Drive diode (bootstrap diode)
60 ... Second drive circuit (shared drive circuit)
61. Insulated power supply

Claims (4)

A secondary battery (12);
AC load (11) operated by AC power;
A charging unit (33) for converting AC power from an AC power source (14) to DC power and supplying the secondary battery to charge the secondary battery;
The charging unit and the AC load share a part of the circuit,
The shared circuit includes a plurality of switching means (21 to 23) and drive circuits (50, 60) for individually driving the switching means,
The plurality of switching means include a common switching means that functions both when driving the AC load and when boosting the secondary battery for charging,
In the shared drive circuit (60) for driving the shared switching means (23), the ON time of the shared switching means is longer than the ON time of the other switching means by the other drive circuit (50). It is comprised as follows. The power control apparatus characterized by the above-mentioned.   The power control apparatus according to claim 1, wherein the shared drive circuit includes a power supply (61) for supplying power for turning on the shared switching means. Each of the drive circuits includes a bootstrap circuit (50),
In the bootstrap circuit in the shared drive circuit, the capacity of the capacitor for bootstrap (51) and the current allowable amount of the diode for bootstrap (54) are such that the capacitor for bootstrap in the other drive circuit and the The power control device according to claim 1, wherein the power control device is larger than the diode.   The power control apparatus according to claim 1, wherein the plurality of switching units are modularized.

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