JP2012120382A - Inverter device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently perform air cooling of an inverter.SOLUTION: An inverter device includes: a first inverter 16 having a plurality of switching elements 18 and converting DC power to AC power to control operation of a first motor; and a second inverter 16 having a plurality of switching elements 18 and converting DC power to AC power to control operation of a second motor. The inverter device further includes: a first flat plate type heat pipe 14 mounted with the switching elements 18 of the first inverter 16; and a second flat plate type heat pipe 14 mounted with the switching elements 18 of the second inverter 16. An air cooling heat radiation fin part 12 is disposed, sandwiched between the first and second flat plate type heat pipes 14. Heat generated in the first and second inverters 16 is released by the air cooling heat radiation fin part 12 via the first and second flat plate type heat pipes 14.

Description

  The present invention relates to an inverter device having an air cooling mechanism using a heat pipe.

  A hybrid vehicle and an electric vehicle travel using the driving force of a motor. For this purpose, the vehicle is equipped with a battery, and the drive of the motor is controlled by converting DC power from the battery into a predetermined AC by an inverter and supplying the AC to the motor.

  Here, the inverter uses a power semiconductor element such as an IGBT as a switching element, switches the current and supplies it to the motor. A motor for a vehicle has a high output, and heat generated in the switching element becomes large, and this cooling mechanism is necessary.

  The cooling mechanism includes water cooling, air cooling, and the like, and the cooling capacity is preferably water cooling, but air cooling is preferable in order to simplify the mechanism.

  As a heat radiating device for semiconductor elements, a device using a heat pipe has been proposed (see Patent Document 1). That is, in Patent Document 1, a semiconductor element is attached to a main heat receiving body, a heat radiating fin is attached to the main heat receiving body, and a sub heat receiving body is disposed at an intermediate portion of the heat radiating fin. And the heat pipe is arrange | positioned between the main heat receiving body and the sub heat receiving body, and the heat transfer from the main heat receiving body to the sub heat receiving body is promoted.

JP-A-8-303969

  In patent document 1, the heat radiation in the whole radiation fin is achieved by providing a sub heat receiving body. However, since the sub heat receiving body is provided, the size is increased, and the heat pipe is also provided on the side of the radiation fin, so that the structure is complicated.

  The present invention includes a first inverter that has a plurality of switching elements, converts DC power to AC power, and controls driving of the first motor, and has a plurality of switching elements, and converts DC power to AC power. A second inverter that controls driving of the two motors, a first flat plate heat pipe having a switching element of the first inverter, a second flat plate heat pipe having a switching element of the second inverter, and the first and A cooling fin for air cooling disposed between the second flat plate heat pipes, and heat generated in the first and second inverters for the air cooling via the first and second heat pipes. Heat is radiated by the radiating fin portion.

  Further, it is preferable that a tubular heat pipe extending from the first or second flat plate heat pipe is provided in the air-cooling radiating fin portion.

  According to the present invention, since the radiating fins are disposed between the two flat plate heat pipes, the radiating fins dissipate heat transmitted from both sides, and the overall radiating effect can be improved. Further, by separately driving the two motors by the two inverters, the wiring to the motor can be efficiently routed even if the two inverters are separated. Furthermore, the heat radiation effect can be increased by embedding a heat pipe in the heat radiation fin portion 12.

1 is a perspective view illustrating an overall configuration of an inverter device 10 according to an embodiment. It is a top view showing the whole inverter device 10 composition concerning an embodiment. It is a front view showing the whole inverter device 10 composition concerning an embodiment. It is a figure which shows an electrical connection. It is a figure which shows the structure of a modification.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1-3 is a figure which shows the whole structure of the inverter apparatus 10 which concerns on embodiment, FIG. 1 is a perspective view, FIG. 2 is a top view, FIG. 3 is a front view. The inverter device 10 has a heat radiating fin portion 12. As the heat dissipating fin portion 12, various known heat dissipating fins that dissipate heat by passing an air flow, such as a configuration in which a large number of flat plates such as aluminum are disposed, for example, can be adopted. A pair of flat plate heat pipes 14 are arranged on both sides of the heat radiating fin portion 12.

  The flat plate heat pipe 14 has a heat radiating portion on the side of the radiating fin portion 12 and a heat absorbing portion on the outside. Here, the heat pipe 14 is obtained by injecting an appropriate amount of a heat medium (working fluid) such as water into the internal space of the flat plate in a vacuum state, in order to promote the return of the absorbed working fluid to the heat radiating side. A capillary structure called a wick is provided on the inner surface of the reflux path. The hydraulic fluid heated and evaporated on the heat absorption side moves to the heat dissipation side by the pressure, and the condensed hydraulic fluid that dissipated the heat returns to the heat absorption side via the wick to perform effective heat transfer.

  And in this embodiment, by connecting the radiation fin part 12 to the heat radiation side surface of the pair of flat plate heat pipes 14, the heat radiation from the pair of heat pipes 14 is sandwiched from both sides of the radiation fin part 12. It supplies to the radiation fin part 12.

  An inverter 16 is mounted on each heat absorption side of the pair of flat plate type heat pipes 14. The inverter 16 is composed of a plurality of switching elements 18 made of power elements such as IGBTs. In this example, six switching elements 18 for converting DC power into three-phase AC are mounted on the heat absorption side surface of the flat plate heat pipe 14. It is also preferable to mount the switching element 18 on the heat absorption side surface of the flat plate type heat pipe 14 via an aluminum substrate or the like that also functions as a heat sink.

  Although not shown, the six switching elements 18 constitute two arms connected in series, each arm is connected between the positive electrode bus and the negative electrode bus, and the middle point of each arm is the motor 3. It is connected to two terminals and supplies U, V, and W phase three-phase AC to the motor. In the present embodiment, the two inverters 16 control the driving of the corresponding motors. For example, one can be a motor / generator that mainly generates power, and the other can be a motor that mainly outputs driving force. Thus, since the two motors are driven separately by the two inverters 16, the wiring to the corresponding motors can be efficiently routed even if the two inverters 16 are separated in position.

  Further, the positive and negative buses of each inverter 16 are constituted by bus bars connected to the battery.

  Further, a tubular heat pipe 20 extending from the heat radiation side surface of the flat plate heat pipe 14 is embedded in the heat radiation fin portion 12. In the illustrated example, a quadrangular prism shape is used, but there is no problem with a cylindrical heat pipe. The heat pipe 20 has a heat absorbing portion on the flat plate heat pipe 14 side, a heat radiating portion on the tip side, and extends almost to the center of the heat radiating fin portion 12. The heat pipe 20 is preferably connected to the heat radiating fins of the heat radiating fin portion 12. The heat pipe 20 can further promote the heat radiation from the flat plate type heat pipe 14. The number of heat pipes 20 embedded in the radiating fin portion 12 may be determined as appropriate, and the number of heat pipes extending from the pair of flat plate heat pipes 14 may be different.

  FIG. 4 shows a circuit configuration of this embodiment. Thus, the wiring from the positive electrode and the negative electrode of the battery 30 is connected to the two inverters 16. In addition, a capacitor 32 is arranged between the positive and negative electrodes of the battery 30 to smooth the output of the battery 30.

  The outputs of the two inverters 16 are connected to the two motors 34, respectively. The DC power from the battery 30 is converted into AC power for driving the motor 34 connected to each of the two inverters 16 to control the driving of the motor 34. As described above, the motor 34 may mainly generate power or output mainly power, but may also perform regenerative braking.

  Note that the output from the battery 30 may not be input to the inverter 16 as it is, but may be input to the inverter 16 after the voltage is converted by the DCDC converter. In this case, the input voltage to the inverter 16 is controlled according to the output of the motor.

  FIG. 5 shows a modified example, in which the capacitor 32 is formed as a plate material connecting the two flat plate heat pipes 14. It is also preferable to form bus bars as wirings on the capacitor 32 in a constant manner. Thereby, the capacitor 32 also functions as a reinforcing material. In addition, since a part of the radiating fin portion 12 is covered by the capacitor 32, it is preferable to install the capacitor 32 at a position where the wind to the radiating fin portion 12 is not blocked. For example, if the wind at the time of running of the vehicle is taken in, the direction is basically limited to one direction. Therefore, when the condenser 32 is attached at a position not blocking this, and a cooling fan is provided, A capacitor should be installed in a position that does not block the wind from the cooling fan.

  According to this embodiment, the radiation fins are sandwiched by the flat plate heat pump having two inverters attached thereto. Therefore, the heat dissipating fins dissipate heat transmitted from both sides, and the heat dissipating effect as a whole can be improved. Moreover, the heat from a plurality of switching elements can be efficiently transmitted to the radiation fins by using the flat plate heat pipe. Further, by separately driving the two motors by the two inverters, the wiring to the motor can be efficiently routed even if the two inverters are separated. Furthermore, the heat radiation effect can be increased by embedding a heat pipe in the heat radiation fin portion 12.

  DESCRIPTION OF SYMBOLS 10 inverter apparatus, 12 radiation fin part, 14 flat plate type heat pipe, 16 inverter, 18 switching element, 20 heat pipe, 30 battery, 32 capacitor | condenser, 34 motor.

Claims (2)

A first inverter having a plurality of switching elements, converting DC power to AC power and controlling driving of the first motor;
A second inverter that has a plurality of switching elements, converts DC power to AC power, and controls driving of the second motor;
A first flat plate heat pipe on which the switching element of the first inverter is mounted;
A second flat plate heat pipe mounting the switching element of the second inverter;
An air-cooling radiating fin portion disposed between the first and second flat plate-type heat pipes;
Have
An inverter device characterized in that heat generated in the first and second inverters is radiated by the air-cooling radiating fin portion through the first and second flat plate heat pipes. The inverter device according to claim 1,
An inverter device comprising a tubular heat pipe extending from the first or second flat plate heat pipe in the air-cooling radiating fin portion.

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