JP2013223384A - Power conversion apparatus and vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve high speed switching, low loss and reliability improvement of a power conversion apparatus.SOLUTION: A power conversion apparatus converts a DC power outputted from a DC power source to an AC power and supplies the AC power to a load. The power conversion apparatus includes an insulating substrate on which a positive electrode terminal pattern connected to a positive electrode terminal of the DC power source, a negative electrode terminal pattern connected to a negative electrode terminal of the DC power source, and an output terminal pattern connected to the load are formed; and semiconductor elements for an upper arm and a lower arm are mounted. One or more smoothing capacitors, whose one end is connected to the positive electrode terminal pattern and the other end is connected to the negative electrode terminal pattern, are mounted on the insulating substrate.

Description

 The present invention relates to a power conversion device and a vehicle.

  In recent years, in order to realize a low-carbon society, research and development of hybrid vehicles using both an engine and a motor as a power source and electric vehicles using only a motor as a power source have been actively conducted. These hybrid vehicles and electric vehicles include an inverter that converts DC power output from an in-vehicle battery such as a nickel metal hydride battery or a lithium ion battery into AC power and supplies the AC power to the motor.

 As described in Patent Document 1 below, this inverter has a series circuit of a capacitor module having a smoothing capacitor and power semiconductor elements for upper and lower arms (for example, insulated gate bipolar transistors: IGBT). The power semiconductor module is electrically and mechanically joined.

JP 2010-63355 A

  In the inverter configured as described above, the wiring inductance between the capacitor module and the power semiconductor module (specifically, the wiring inductance between the insulating substrate on which the power semiconductor element is mounted and the smoothing capacitor) has conventionally been a cause of surge voltage. Therefore, how to reduce the wiring inductance has been a major issue in realizing high-speed switching, low loss, and improved reliability of the inverter.

 This invention is made | formed in view of the situation mentioned above, and aims at providing the vehicle provided with the power converter device which can implement | achieve high-speed switching, low loss, and a reliability improvement, and the power converter device. .

 In order to achieve the above object, in the present invention, as a first solving means related to a power converter, in a power converter that converts DC power output from a DC power source into AC power and supplies the AC power to a load, the DC converter A positive electrode terminal pattern connected to the positive electrode terminal of the power supply, a negative electrode terminal pattern connected to the negative electrode terminal of the DC power supply, and an output terminal pattern connected to the load are formed, and the semiconductor elements for the upper arm and the lower arm are formed. A means is adopted in which one or more smoothing capacitors, each having a mounted insulating substrate, one end connected to the positive terminal pattern and the other end connected to the negative terminal pattern, are mounted on the insulating substrate. .

 Further, in the present invention, as a second solving means relating to the power converter, in the first solving means, an external capacitor having one end connected to the positive terminal pattern and the other end connected to the negative terminal pattern Adopts a means in which one or more are attached to the insulating substrate.

 On the other hand, in the present invention, as a first solving means relating to a vehicle, a rechargeable DC power source, a motor used as a power source, and a DC power output from the DC power source are converted into AC power to convert the motor And the power converter is connected to the positive terminal pattern connected to the positive terminal of the DC power source, the negative terminal pattern connected to the negative terminal of the DC power source, and the motor. And a smoothing capacitor having an insulating substrate on which semiconductor elements for upper and lower arms are mounted, one end connected to the positive terminal pattern and the other end connected to the negative terminal pattern Adopts a means that at least one is mounted on the insulating substrate.

 According to the present invention, as the second solving means relating to the vehicle, in the first solving means, in the power conversion device, one end is connected to the positive terminal pattern and the other end is connected to the negative terminal pattern. Further, one or more external capacitors are externally attached to the insulating substrate.

 According to the present invention, since the wiring inductance between the insulating substrate on which the semiconductor element is mounted and the smoothing capacitor is greatly reduced, it is possible to realize high-speed switching, low loss, and improved reliability of the power converter.

FIG. 4 is a circuit configuration diagram (a) of an inverter 1 that is a power conversion device according to the first embodiment, and a plan view (b) of an insulating substrate 40 ′ for mounting a power semiconductor element included in the power semiconductor module 30 ′. It is a circuit block diagram of the inverter 2 which is the power converter device which concerns on 2nd Embodiment. It is a figure which shows the example of application of the inverter 1 or 2 with respect to an electric vehicle. FIG. 2 is a circuit configuration diagram (a) of a general inverter 10 and a plan view (b) of an insulating substrate 40 for mounting a power semiconductor element included in the power semiconductor module 30.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
First, in order to facilitate understanding of the power conversion device according to the present embodiment, a general configuration and problems of a conventional power conversion device (inverter) will be described with reference to FIG.

  FIG. 4A is a circuit configuration diagram of the conventional inverter 10. The inverter 10 converts DC power output from the DC power supply 100 into, for example, three-phase AC power (U-phase, V-phase, W-phase) and supplies it to the load 200. The capacitor module 20 and the power semiconductor module 30.

  The capacitor module 20 includes a positive electrode side input terminal 21, a negative electrode side input terminal 22, a positive electrode side output terminal 23, a negative electrode side output terminal 24, and a smoothing capacitor 25. The positive input terminal 21 is connected to the positive terminal of the DC power supply 100, and the negative input terminal 22 is connected to the negative terminal of the DC power supply 100. The positive output terminal 23 is connected to the positive input terminal 21 inside the capacitor module 20, and the negative output terminal 24 is connected to the negative input terminal 22 inside the capacitor module 20.

  The smoothing capacitor 25 has one end connected to the positive input terminal 21 and the positive output terminal 23 and the other end connected to the negative input terminal 22 and the negative output terminal 24 inside the capacitor module 20. That is, the smoothing capacitor 25 is connected to the DC power supply 100 in parallel.

  The power semiconductor module 30 includes a positive side input terminal 31, a negative side input terminal 32, a U phase output terminal 33, a V phase output terminal 34, a W phase output terminal 35, a power semiconductor element 36a for the upper arm, 36b, 36c, lower arm power semiconductor elements 36d, 36e, 36f, upper arm free-wheeling diodes 37a, 37b, 37c, and lower arm free-wheeling diodes 37d, 37e, 37f.

  The positive input terminal 31 is connected to the positive output terminal 23 of the capacitor module 20, and the negative input terminal 32 is connected to the negative output terminal 24 of the capacitor module 20. The U-phase output terminal 33, the V-phase output terminal 34, and the W-phase output terminal 35 are each connected to the load 200.

  The power semiconductor elements 36a, 36b, 36c for the upper arm and the power semiconductor elements 36d, 36e, 36f for the lower arm are, for example, IGBTs (insulated gate bipolar transistors), and are used for the upper arm and the lower arm that form a pair. The power semiconductor elements are connected in series to form three series circuits. That is, there are three series: a series circuit of power semiconductor elements 36a and 36d, a series circuit of power semiconductor elements 36b and 36e, and a series circuit of power semiconductor elements 36c and 36f.

  Specifically, for example, focusing on the series circuit of the power semiconductor elements 36a and 36d, the emitter terminal of the power semiconductor element 36a and the collector terminal of the power semiconductor element 36d are connected. The series circuit of the power semiconductor elements 36b and 36e and the series circuit of the power semiconductor elements 36c and 36f have the same connection form.

  The three series circuits including the power semiconductor elements for the upper arm and the lower arm are connected in parallel between the positive input terminal 31 and the negative input terminal 32 in the power semiconductor module 30. Specifically, for example, focusing on the series circuit of the power semiconductor elements 36a and 36d, the collector terminal of the power semiconductor element 36a is connected to the positive input terminal 31 and the emitter terminal of the power semiconductor element 36d is connected to the negative input terminal 32. Has been.

  The series circuit of the power semiconductor elements 36b and 36e and the series circuit of the power semiconductor elements 36c and 36f have the same connection form. That is, the three series circuits composed of the power semiconductor elements for the upper arm and the lower arm are connected in parallel to the DC power supply 100 and the smoothing capacitor 25.

  The midpoint portion of the series circuit of the power semiconductor elements 36a and 36d is connected to the U-phase output terminal 33, and the midpoint portion of the series circuit of the power semiconductor elements 36b and 36e is connected to the V-phase output terminal 34. A midpoint portion of the series circuit of the power semiconductor elements 36 c and 36 f is connected to the W-phase output terminal 35.

  The upper arm free-wheeling diodes 37a, 37b, and 37c are connected in parallel to the upper-arm power semiconductor elements 36a, 36b, and 36c, respectively, and the lower-arm free-wheeling diodes 37d, 37e, and 37f are respectively connected to the lower arm power semiconductor devices The semiconductor elements 36d, 36e, and 36f are connected in parallel. Specifically, for example, focusing on the freewheeling diode 37a, the anode terminal is connected to the emitter terminal of the power semiconductor element 36a, and the cathode terminal is connected to the collector terminal of the power semiconductor element 36a. The same applies to the other free-wheeling diodes 37b to 37f.

  Originally, the power semiconductor module 30 is provided with an external signal input terminal for inputting a switching control signal (for example, a PWM signal) to the gate terminals of the power semiconductor elements 36a to 36f. For convenience, illustration is omitted in FIG.

  FIG. 4B is a plan view of an insulating substrate 40 for mounting a power semiconductor element included in the power semiconductor module 30. As shown in this figure, on the surface layer of the insulating substrate 40 (for example, aluminum nitride plate), various conductor patterns made of, for example, copper or aluminum, for example, the positive electrode terminal of the DC power source 100 through the positive electrode side input terminal 31 are used. A positive terminal pattern 41 connected, a negative terminal pattern 42 connected to the negative terminal of the DC power source 100 via the negative input terminal 32, and an output terminal pattern connected to the load 200 via the U-phase output terminal 33 43, a first conductor pattern 44, and a second conductor pattern 45 are formed.

  On the insulating substrate 40, the upper arm power semiconductor element 36 a is mounted on the upper surface of the first conductor pattern 44 via solder, and the lower arm power is mounted on the upper surface of the second conductor pattern 45 via solder. A semiconductor element 36d is mounted. The positive electrode terminal pattern 41 and the first conductor pattern 44 are connected by an aluminum wire 46, and the power semiconductor element 36a and the second conductor pattern 45 are connected by an aluminum wire 47, and the power semiconductor element 36d and the negative electrode terminal pattern are connected. 42 is connected by an aluminum wire 48, and the second conductor pattern 45 and the output terminal pattern 43 are connected by an aluminum wire 49.

  Thus, on the insulating substrate 40, the series circuit of the power semiconductor elements 36a and 36d shown in FIG. 4A is formed. The positive electrode side input terminal 31 and the positive electrode terminal pattern 41 of the insulating substrate 40 are connected to each other by an aluminum wire (not shown) inside the power semiconductor module 30. Similarly, the negative electrode side input terminal 32 and the negative electrode terminal pattern 42 of the insulating substrate 40 are also connected within the power semiconductor module 30 by an aluminum wire (not shown), and the U phase output terminal 33 and the output terminal of the insulating substrate 40 are connected. The pattern 43 is also connected by an aluminum wire (not shown).

  4B illustrates the case where only the series circuit of the power semiconductor elements 36a and 36d is formed on one insulating substrate 40, the power semiconductor module 30 has the same configuration as the power semiconductor. An insulating substrate on which a series circuit of elements 36b and 36e is formed and an insulating substrate on which a series circuit of power semiconductor elements 36c and 36f is formed are also provided. Even if three series of power semiconductor elements 36a and 36d, a series circuit of power semiconductor elements 36b and 36e, and a series circuit of power semiconductor elements 36c and 36f are formed on one insulating substrate 40. good. In FIG. 4B, the free-wheeling diodes 37a and 37d connected in parallel to the power semiconductor elements 36a and 36d are omitted.

  In the inverter 10 having the above-described configuration, the wiring inductance between the capacitor module 20 and the power semiconductor module 30 (specifically, the wiring inductance between the smoothing capacitor 25 and the insulating substrate 40) has hitherto been noted as a cause of surge voltage generation. Thus, how to reduce the wiring inductance has been a major issue in realizing high-speed switching, low loss, and improved reliability of the inverter 10.

  The power conversion device according to the present embodiment solves the problems of the conventional inverter 10 as described above, and realizes high-speed switching, low loss, and improved reliability. Hereinafter, the power converters according to the first and second embodiments of the present invention will be described with reference to the drawings. For convenience of explanation, the same components as those of the conventional inverter 10 shown in FIG. A description thereof will be omitted.

[First Embodiment]
Fig.1 (a) is a circuit block diagram of the inverter 1 which is the power converter device which concerns on 1st Embodiment of this invention. As shown in this figure, in the inverter 1 according to the first embodiment, compared to the conventional inverter 10 (see FIG. 4A), the capacitor module 20 is deleted, and a power semiconductor module 30 (hereinafter, conventional) The positive side input terminal 31 of the power semiconductor module 30 'is directly connected to the DC power source 100. The positive side input terminal 31 of the power source module 30' is directly connected to the positive terminal of the DC power source 100. The smoothing capacitor 38 is further provided inside the power semiconductor module 30 ′.

  Specifically, as shown in FIG. 1B, one end is connected to a positive electrode terminal pattern 41 of an insulating substrate 40 (hereinafter, the reference numeral 40 ′ is used to distinguish it from the conventional one), and the other end is insulated substrate 40. One or more smoothing capacitors 38 (for example, chip capacitors) connected to the negative electrode terminal pattern 42 are mounted on the insulating substrate 40 ′.

  Further, in FIG. 1B, the positive electrode terminal pattern 41 has a convex portion, and the negative electrode terminal pattern 42 has a concave portion. The positive electrode terminal pattern 41 has a convex portion that is a concave portion of the negative electrode terminal pattern 42. The pattern is formed in the form inserted into the. By adopting such a pattern shape, the number of smoothing capacitors 38 to be mounted (the number of parallel connections) can be increased. The shape of the positive terminal pattern 41 and the negative terminal pattern 42 can be freely set as long as the required number of smoothing capacitors 38 can be secured.

  According to the inverter 1 having such a configuration, the wiring inductance between the smoothing capacitor 38 and the insulating substrate 40 ′ is greatly reduced, so that high-speed switching, low loss and improved reliability of the inverter 1 can be realized. . Further, since the capacitor module 20 is not necessary, the inverter 1 can be downsized.

[Second Embodiment]
FIG. 2 is a circuit configuration diagram of an inverter 2 that is a power conversion device according to the second embodiment of the present invention. As shown in this figure, in the inverter 2 according to the second embodiment, the capacitor module 20 is connected between the DC power supply 100 and the power semiconductor module 30 ′ as compared with the inverter 1 according to the first embodiment. It is different in point. That is, in the inverter 2 according to the second embodiment, an external capacitor (smoothing capacitor 25) having one end connected to the positive terminal pattern 31 of the insulating substrate 40 ′ and the other end connected to the negative terminal pattern 32 of the insulating substrate 40 ′. ) Are externally attached to the insulating substrate 40 '.

 In the inverter 1 according to the first embodiment, when the DC input voltage to the power semiconductor module 30 ′ becomes high, the capacity of the chip capacitor is reduced, and it is necessary and sufficient even if the number of mounted smoothing capacitors 38 is increased. A large capacity cannot be obtained. In this case, like the inverter 2 according to the second embodiment, the smoothing capacitor 38 that is a chip capacitor is mounted inside the power semiconductor module 30 ′, and the insufficient capacity is provided by an external capacitor (smoothing capacitor 25). Complementary configuration.

 As a result, the charge Qrr due to the recovery of the free-wheeling diodes 37a to 37f can be supplied by the smoothing capacitor 38 in the power semiconductor module 30 ′, and the occurrence of recovery surge that becomes a surge voltage and noise generation source in the inverter 2 is greatly increased. Can be suppressed.

[Application example]
FIG. 3 is a diagram illustrating an example in which the above-described inverter 1 or 2 is applied to a vehicle (in this case, an electric vehicle). As shown in this figure, the electric vehicle 300 according to this embodiment includes the above-described inverter 1 (or 2), in-vehicle battery 301, battery charger 302, connection destination switch 303, motor 304, and motor ECU (Electric Control Unit). 305 and a battery ECU 306.

  The in-vehicle battery 301 is composed of a plurality of battery cells connected in series (for example, lithium ion battery cells, nickel metal hydride battery cells, etc.), and is a rechargeable DC power source that outputs DC power of several hundred volts, for example. . Both terminals (a positive terminal and a negative terminal) of the in-vehicle battery 301 are connected to a connection destination switch 303.

  The battery charger 302 is a charging circuit that is connected to an AC power source 400 installed outside the electric vehicle 300 when the in-vehicle battery 301 is charged, and receives AC power supplied from the AC power source 400 under the control of the battery ECU 306. It is converted into DC power having a predetermined voltage value and output to the connection destination switch 303.

  Under the control of the battery ECU 306, the connection destination switch 303 switches the connection destination of both terminals of the in-vehicle battery 301 to both output terminals of the battery charger 302 during charging, and the inverter 1 during discharging (when driving the motor 304). (Or 2) both input terminals (in the case of the inverter 1, the positive input terminal 31 and the negative input terminal 32 of the power semiconductor module 30 ′, and in the case of the inverter 2, the positive input terminal 21 of the capacitor module 20. And the negative input terminal 22).

  The inverter 1 (or 2) is input from the in-vehicle battery 301 via the connection destination switch 303 by performing a switching operation in accordance with the PWM signal input from the motor ECU 305 to the gate terminals of the power semiconductor elements 36a to 36f. The high-voltage DC power that is generated is converted into three-phase AC power and output to the motor 304. The motor 304 is, for example, a three-phase AC motor used as a power source of the electric vehicle 300, and rotates according to the three-phase AC power supplied from the inverter 1 (or 2). The motor 304 rotationally drives the wheels via a transmission, an axle, etc. (not shown).

  The motor ECU 305 is communicably connected to the battery ECU 306, and when receiving a drive request for the motor 304 from the battery ECU 306 (when the connection destination of the vehicle-mounted battery 301 is switched to the inverter 1 (or 2)), the inverter A PWM signal to be supplied to 1 (or 2) is generated. The motor ECU 305 is also communicably connected to a host ECU (not shown), and changes the duty ratio and frequency of the PWM signal in accordance with driving information (for example, accelerator depression amount) transmitted from the host ECU. Thus, the rotation state of the motor 304 is controlled.

  The battery ECU 306 is an electronic control device that performs charge / discharge control of the in-vehicle battery 301. The battery ECU 306 controls the connection destination switch 303 to connect the connection destination of the in-vehicle battery 301 to the battery charger 302 during charging and to the inverter 1 (or alternatively) during discharging. Switch to 2). When charging the in-vehicle battery 301, the battery ECU 306 controls the battery charger 302 while monitoring the voltage state of the in-vehicle battery 301 so that the in-vehicle battery 301 is charged to an appropriate voltage value.

 The inverters 1 and 2 and the application examples thereof according to the first and second embodiments of the present invention have been described above, but the present invention is not limited to this, and various modifications can be made without departing from the spirit of the present invention. Of course there is. For example, in the above application example, the example in which the inverter 1 or 2 is applied to the electric vehicle 300 has been described. However, the present invention is used as a rechargeable DC power source and a power source, such as a hybrid vehicle or a plug-in hybrid vehicle. The present invention can be widely applied to vehicles including a motor to be used (of course, it can be applied to uses other than vehicles).

  DESCRIPTION OF SYMBOLS 1, 2, 10 ... Inverter (power converter), 20 ... Capacitor module, 30, 30 '... Power semiconductor module, 25, 38 ... Smoothing capacitor, 40, 40' ... Insulating substrate, 100 ... DC power supply, 200 ... Load , 300 ... Electric car

Claims (4)

In a power conversion device that converts DC power output from a DC power source into AC power and supplies it to a load,
A positive terminal pattern connected to the positive terminal of the DC power source, a negative terminal pattern connected to the negative terminal of the DC power source, and an output terminal pattern connected to the load are formed. It has an insulating substrate on which the element is mounted,
One or more smoothing capacitors having one end connected to the positive terminal pattern and the other end connected to the negative terminal pattern are mounted on the insulating substrate.   2. The power conversion according to claim 1, wherein at least one external capacitor having one end connected to the positive terminal pattern and the other end connected to the negative terminal pattern is externally attached to the insulating substrate. apparatus. Rechargeable DC power supply,
A motor used as a power source;
A power conversion device that converts DC power output from the DC power source into AC power and supplies the motor to the motor, and
The power converter is
A positive terminal pattern connected to the positive terminal of the DC power source, a negative terminal pattern connected to the negative terminal of the DC power source, and an output terminal pattern connected to the motor are formed, and semiconductors for the upper arm and the lower arm It has an insulating substrate on which the element is mounted,
One or more smoothing capacitors having one end connected to the positive terminal pattern and the other end connected to the negative terminal pattern are mounted on the insulating substrate.   2. The power converter according to claim 1, wherein at least one external capacitor having one end connected to the positive terminal pattern and the other end connected to the negative terminal pattern is externally attached to the insulating substrate. 3. The vehicle according to 3.

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