JP2011135666A - Power converter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power converter, which prevents the functional deterioration of a device in a hot environment or the acceleration of deterioration of structural components and besides suppresses the enlargement due to multi-functionality. <P>SOLUTION: The power converter includes a water path forming body, a power module which has a power semiconductor element and is fixed to the water path forming body, an electronic circuit which has a heat-resistant temperature larger than the heat-resistant temperature of the power semiconductor element, and a casing for housing the power module, the water path forming body, and discharge circuit parts. The water path forming body has a protrusion which projects from the specified face of the water path forming body and is fixed to the inwall side of the specified face of the casing via the protrusion. The electronic circuit parts are arranged in space formed by the protrusion between the water path forming body and the casing, and besides are fixed to the specified face side of the water path forming body. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a power conversion device, and more particularly to a power conversion device used for a hybrid electric vehicle.

  The power converter is mainly composed of an inverter main circuit, a smoothing capacitor connected in parallel to a DC power supply terminal of the inverter main circuit, and a control circuit for controlling the inverter main circuit. The inverter main circuit has a plurality of power semiconductors, and the plurality of power semiconductors constitute a power module with a predetermined number as a unit. For this reason, the inverter main circuit is configured as one or a plurality of power modules including a plurality of power semiconductors.

  In pure electric vehicles that operate by the output of an electric motor without using an internal combustion engine, or hybrid electric vehicles that use an internal combustion engine in combination, the ratio of the interior to the overall volume of the vehicle should be as large as possible to improve comfort. Is desired. For this reason, it is desired that the power conversion device be mounted in the smallest possible space outside the passenger compartment, particularly in the engine room.

  In addition, rotating electrical machines mounted on vehicles tend to have higher power and higher voltage, and as a solution to this, a power module arrangement with reduced inductance is provided so that the withstand voltage of components can be increased. (Patent Document 1).

  However, the temperature environment in the engine room is higher than the conventional use environment, and the use in a high temperature range, in particular, may accelerate the deterioration of the control function of the power conversion device and the deterioration of the structural components.

JP 2008-228502 A

  In view of the above, an object of the present invention is to provide a power conversion device that prevents deterioration of the function of the device due to a high temperature environment and the promotion of deterioration of structural parts, and suppresses the increase in size due to multi-function.

  In order to solve the above-described problems, a power conversion device according to the present invention is a power conversion device used in a hybrid vehicle driven by an engine driving force and a motor driving force, and forms a water channel for flowing a cooling medium. A water channel forming body, a power module having a power semiconductor element for converting a direct current into an alternating current, and fixed to the water path forming body, a smoothing capacitor module for smoothing the direct current, An electronic circuit component having a heat resistance temperature greater than the heat resistance temperature of the power semiconductor element, and a housing for storing the power module, the smoothing capacitor module, the water channel formation body, and the discharge circuit component, The power conversion device is disposed such that a predetermined surface of the outer wall of the housing faces the engine, and the water channel forming body is A projecting portion projecting from a predetermined surface of the path forming body, and fixed to an inner wall side of the predetermined surface of the housing via the projecting portion, and the electronic circuit component includes the water channel forming body and the housing Is disposed in a space formed by the protruding portion, and is fixed to the predetermined surface side of the water channel forming body.

  In the power conversion device according to the present invention, preferably, the electronic circuit component is a discharge resistor for discharging the electric charge stored in the smoothing capacitor module.

  The power conversion device according to the present invention preferably includes an AC bus bar that transmits the AC current output from the power module and is wired so as to pass through the space. It is a current sensor for detecting a current value for energizing the bus bar, and the current sensor is disposed in the space.

  The effects of the present invention can provide a power conversion device that prevents the deterioration of structural components even in a high temperature environment and suppresses an increase in size due to multifunctional functions.

It is a system diagram showing an example of a hybrid electric vehicle equipped with the power conversion device of the present embodiment. It is a see-through | perspective perspective schematic diagram of the engine room part of the hybrid electric vehicle with which the power converter device of this embodiment was provided. It is an external appearance perspective view which shows one Example of the power converter device by this embodiment. It is the figure which showed one Example of the power converter device by this embodiment from the side surface side. It is a perspective bird's-eye view of one example of the power converter by this embodiment. It is the external appearance perspective view which showed the water channel formation body with which the power converter device by this embodiment was provided from the lower side. It is the external appearance perspective view which showed the terminal block box with which the power converter device by this embodiment was equipped. 3 is a cross-sectional view taken along line VV. It is a temperature measurement arrangement | positioning figure of a power converter device. It is the temperature measurement result of the power converter device in a high temperature use environment. The calculation condition details and calculation results of heat transfer and thermal resistance. 3 is a cross-sectional view taken along line CC. 3 is a cross-sectional view taken along line VV.

  Hereinafter, embodiments of the power conversion device according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a circuit configuration diagram showing an example of a hybrid electric vehicle 110 provided with the power conversion device of the present embodiment. In this embodiment, the power system is indicated by a solid line and the signal system is indicated by a dotted line so that the power system and the signal system can be easily distinguished.

  Naturally, the power conversion apparatus 100 of the present embodiment can also be applied to a pure electric vehicle. In this case, the basic configuration and basic operation have many common parts between the hybrid electric vehicle and the pure electric vehicle. For this reason, in the following description, the example of the hybrid electric vehicle 110 is described on behalf of these.

  The hybrid electric vehicle 110 is provided with a power conversion device 100. Details of the system of the power conversion apparatus 100 in the present embodiment will be described below. The power conversion apparatus 100 includes a capacitor module 35 having a plurality of smoothing capacitors that suppresses voltage fluctuations of a DC power supply, a first power module 140 that incorporates a plurality of power semiconductors, a second power module 141, and an oil pump power. A board provided with a switching drive circuit for controlling the switching operation of the module 142 and the first power module 140, the second power module 141, and the oil pump power module 142 (hereinafter referred to as drive circuit boards 127, 128, and 129). And a board (hereinafter referred to as a control circuit board 3 and an oil pump control circuit board 6) provided with a rotating electrical machine control circuit that generates a signal for determining a time width of a switching operation, that is, a PWM signal for controlling pulse-wide modulation. Has been.

  The first power module 140 drives the first rotating electrical machine 193, the second power module 141 drives the second rotating electrical machine 194, and the third power module 142 drives the third rotating electrical machine 192, respectively.

  By electrically connecting the first power module 140, the second power module 141, and the oil pump power module 142, the first power module 140, the second power module 141, and the oil pump power module 142 are An inverter main circuit is configured by electrically connecting power semiconductors having the same. A signal for controlling the power semiconductor constituting the inverter main circuit is generated by the control circuit board 3 and sent to the drive circuit boards 127 and 128. The signal generated by the oil pump control circuit board 6 is sent to the oil pump drive circuit board 129.

  The drive circuit boards 127, 128, and 129 are so-called power semiconductor gate drive circuits, and generate gate drive signals supplied to the gate terminals of the power semiconductors. The gate drive signal is sent to the gate terminal of each power semiconductor, and each power semiconductor performs a switching operation based on the gate drive signal.

  Further, the DC power supplied from the high voltage battery 136 is supplied to the DC / DC converter device 135 via the DC capacitor module 18 having a smoothing capacitor that suppresses voltage fluctuation of the DC power supply.

  The hybrid electric vehicle 110 having the front wheels 112 is supplied with high-voltage DC power to the engine 117, the first rotating electrical machine 193, the second rotating electrical machine 194, the first rotating electrical machine 193, and the second rotating electrical machine 194. A high voltage battery 136 is mounted. Actually, the rear wheel 113, the rear wheel axle 115, and the low voltage battery 137 for supplying low voltage power (14 volt system power) are mounted, and power for supplying power to a control circuit described below is supplied. .

  Further, the rotational torque based on the engine 117 and the first rotating electrical machine 193 and the second rotating electrical machine 194 is transmitted to the power transmission mechanism 116. This rotational torque is transmitted to the front wheel 112 via the front wheel axle 114.

  The transmission control device 131 that controls the transmission 195, the engine control device 133 that controls the engine 117, the rotating electrical machine control circuit board 3 that controls the power conversion device 100, and the battery control device 132 that controls the high voltage battery 136 are local. It is connected to the general control device 130 via a communication line 134 such as an area network.

  In addition, the general control device 130 sends information representing the respective states from the transmission control device 131, the engine control device 133, the power conversion device 100, or the battery control device 132, which are lower-order control devices, to the communication line 134. Receive through. Such information is used for integrated control of the vehicle from the viewpoint of safety and the like.

  The integrated control of the vehicle is a control achieved by the cooperative operation of the control devices, and control commands to the control devices for realizing the integrated control of the vehicle are respectively sent from the general control device 130 via the communication line 134. To the control device.

  For example, the battery control device 132 reports the discharge status of the high voltage battery 136 and the state of each cell battery constituting the battery to the general control device 130. In addition, when it is determined from the above report that the high voltage battery 136 needs to be charged, the integrated control device 130 instructs the power conversion device 100 to generate power. The comprehensive control device 130 manages the output torque of the engine 117 and the first rotating electrical machine 193 and the second rotating electrical machine 194, and the overall output torque of the engine 117, the first rotating electrical machine 193, and the second rotating electrical machine 194. Torque or torque distribution ratio is obtained by calculation processing.

  A control command based on the processing result is transmitted to the transmission control device 131, the engine control device 133, or the power conversion device 100. Based on the torque command, the power conversion apparatus 100 controls the first rotating electrical machine 193 and the second rotating electrical machine 194 so as to generate a torque output of the command at one or both of the rotating electrical machines. In addition, these rotating electric machines are controlled.

  The first rotating electrical machine 193 and the second rotating electrical machine 194 have a structure that can operate as an electric motor or a generator. For example, when the first rotating electrical machine 193 operates as an electric motor, the second rotating electrical machine 194 can be operated as an electric motor or a generator.

  As described above, based on the driving state of the vehicle, the overall control device 130 determines each target torque by calculating the distribution between the output torque of the engine 117 and the output torque of the rotating electrical machine. Then, the target torque of the first rotating electrical machine 193 and the second rotating electrical machine 194 is transmitted to the power conversion device 100 via the communication line 134 as a torque command.

  Based on the command, the power conversion device 100 determines whether the first rotating electrical machine 193 and the second rotating electrical machine 194 are each operated as an electric motor or an electric generator by arithmetic processing, and performs the first rotation. The electric machine 193 and the second rotating electric machine 194 are controlled.

  As another embodiment, whether to operate the first rotating electric machine 193 and the second rotating electric machine 194 as an electric motor or an electric generator can be determined by calculation in the overall control device 130. According to this method, the first rotating electrical machine 193 or the second rotating electrical machine 194 is subjected to the generated torque in the case of motor operation, and the generated power in the case of generator operation. 130 is determined. The content is transmitted as a command to the power conversion apparatus 100 via the communication line 134.

  In any method, the power conversion apparatus 100 performs the switching operation of the power semiconductor that constitutes the inverter main circuit in order to operate the first rotating electrical machine 193 and the second rotating electrical machine 194 based on a command from the comprehensive control apparatus 130. To control. By the switching operation of these power semiconductors, the first rotating electrical machine 193 and the second rotating electrical machine 194 are operated as an electric motor or a generator.

  When the first rotating electrical machine 193 or the second rotating electrical machine 194 is operated as an electric motor, DC power from the high-voltage battery 136 is applied to the inverter main circuit of the power converter 100. By controlling the switching operation of the power semiconductor constituting the inverter main circuit, the DC power is converted into a three-phase AC current. This AC current is sent to the first rotating electrical machine 193 via the U-phase AC circuit 118-a, V-phase AC circuit 119-a, and W-phase AC circuit 120-a, and to the U-phase AC circuit 118-b and V-phase AC. The electric power is supplied to the second rotating electrical machine 194 via the circuit 119-b and the W-phase AC circuit 120-b. As a result, the first rotating electrical machine 193 or the second rotating electrical machine 194 generates rotational torque as an electric motor.

  In such a state where the first rotating electrical machine 193 or the second rotating electrical machine 194 is operated as an electric motor and the engine 117 is stopped, a mechanical oil pump connected to the engine 117 that supplies hydraulic pressure to the transmission. Has also stopped. In order to supply hydraulic pressure to the transmission even when the engine 117 is stopped, the power conversion device 100 is driven by an inverter main unit for operating the rotary electric machine 192 for driving the oil pump based on a command from the general control device 130. The switching operation of the power semiconductor constituting the circuit is controlled. When the oil pump driving rotary electric machine 192 is operated, DC power from the high voltage battery 136 is applied to the inverter main circuit of the power converter 100. By controlling the switching operation of the power semiconductor constituting the inverter main circuit, the DC power is converted into a three-phase AC current. The alternating current is supplied to the oil pump driving rotating electrical machine 192 via the U phase AC circuit 118-c, the V phase AC circuit 119-c, and the W phase AC circuit 120-c, and the oil pump driving rotating electrical machine 192 is supplied. Can drive and supply hydraulic pressure to the transmission.

  On the other hand, when the first rotating electrical machine 193 or the second rotating electrical machine 194 is operated as a generator, the rotor of the first rotating electrical machine 193 or the second rotating electrical machine 194 rotates with a rotational torque from the outside. . Based on this rotational torque, three-phase AC power is generated in the stator winding of the rotating electrical machine. The generated three-phase AC power is converted into DC power by the power converter 100. This DC power is supplied to the high voltage battery 136, and the high voltage battery 136 is charged.

  The engine 117 and the first rotating electrical machine 193 or the second rotating electrical machine 194 shown in FIG. 1 may be mechanically directly connected by a rotating shaft, or may be connected via a gear or a clutch. Also good. When the engine 117, the first rotating electrical machine 193, and the second rotating electrical machine 194 are directly connected, the first rotating electrical machine 193 and the second rotating electrical machine 194 are directly proportional to the rotational speed of the engine 117. Rotates. For this reason, the first rotating electrical machine 193 and the second rotating electrical machine 194 vary in rotational speed over a wide range from the rotation stopped state to the high speed rotating state. Therefore, the first rotating electrical machine 193 and the second rotating electrical machine 194 need mechanical strength so that they can withstand high-speed rotation.

  Next, FIG. 3 shows an external perspective view of the power conversion apparatus 100 in this embodiment, and FIG. 4 shows a side view thereof. As shown in FIGS. 3 and 4, the power conversion apparatus 100 is configured as a compact shape.

  The power conversion apparatus 100 has a case 14 made of a metal material such as aluminum. The case 14 is made of a metal material such as aluminum, has a substantially rectangular housing, and has an upper surface opened. The upper opening is finally closed by the cover 1. Further, a cooling water inlet pipe 15 for introducing cooling water and a cooling water outlet pipe 16 for discharging cooling water are provided in the power converter. Further, the side surface of the case 14 is opened, and a terminal block box 8 for fixing a terminal for power input / output is disposed.

  In addition, an airtight holding component such as a gasket or an O-ring is disposed at a joint portion between the case 14, the cover 1, and the terminal block box 8 to ensure waterproofness and airtightness. Each opening and cooling water pipe may be an upper surface portion or a bottom surface portion depending on the arrangement state of the power conversion device 100 in the vehicle.

  The configuration of the terminal block box 8 is shown in FIG. The terminal block box 8 is covered with a terminal block case 21 of a substantially rectangular housing made of a metal material such as aluminum and a terminal block cover 20 for closing the opening. Inside the terminal block case 21, a capacitor module 18 having a plurality of smoothing capacitors that suppress voltage fluctuations of the DC power supply is disposed.

  In addition, a current sensor 19 for detecting and controlling a three-phase alternating current converted from a direct current by the power conversion device 100 is disposed. Further, adjacent to the current sensor 19, an output from the power conversion device 100 is provided. The AC bus bar forming the three-phase AC current circuit and the terminals from the vehicle side of the high voltage battery 136, the first rotating electrical machine 193, and the second rotating electrical machine 194 as shown in FIG. Thus, a terminal block 38 for connection is arranged.

  An airtight holding component such as a gasket or an O-ring is arranged at a joint portion between the terminal block case 21, the terminal block cover 20, and the power conversion device main body to ensure waterproofness and airtightness.

  FIG. 5 is an exploded bird's-eye view of the power conversion apparatus 100. A water channel forming body 9 having a cooling water channel is disposed inside the case 14. A cooling water inlet pipe 15 for introducing cooling water into the water channel forming body 9 and a cooling water outlet pipe 16 for discharging cooling water from the water channel forming body 9 are provided on the front surface of the case 14 and the water channel forming body 9. ing.

  The oil pump power module 142 is disposed on the back surface of the water channel forming body 9 in contact with the cooling water channel of the water channel forming body 9 through a metal base incorporated in the oil pump power module 142. The

  Similarly, the base 5 on which the control circuit board 3 and the oil pump control circuit board 6 are mounted is disposed in contact with the cooling water channel on the back surface of the water channel forming body 9. Further, in order to shield the motor switching noise, the electromagnetic wave shielding plates 2, 10, 11, and 17 arranged with a sufficient insulation distance between the insulating material or the structural parts made of a conductor material are provided in the case. 14 is arranged inside.

  The shielding plate 2 also serves as a stopper, and binds and fixes various wirings such as the high-voltage DC connector 12 and the oil pump control connector 13 using bands and clips.

  Next, the cooling structure in the present embodiment will be described with reference to FIGS. As described above, in this embodiment, the power conversion apparatus 100 includes the water channel forming body 9 for cooling the component parts (particularly, electronic parts having low heat resistance and requiring cooling).

  The structure of the water channel formation body 9 disposed inside the case 14 is shown in FIG. The water channel case 23 serving as a base is provided with a fixing leg 33 for supporting the case 14 with screws or the like. The fixed leg 33 protrudes from the predetermined surface of the water channel formation body 9 to form a protrusion. The fixed leg 33 requires mechanical strength capable of supporting the water channel housing and the attached components, and further, the contact area between the case 14 and the fixed leg 33 is as small as possible in order to minimize heat transfer from the outside. Smaller is better.

  In addition, a gap 34 is provided in the bottom surface of the water channel case 23, and has a function of preventing current leakage by stopping energization when the circuit of the resistor 24, the resistor 25, and the power conversion device is disconnected. High-voltage leak detection board 26, output U-phase AC bus bars 27 and 30 for connecting the power module and the rotating electrical machine, V-phase AC bus bars 28 and 31, and W-phase AC bus bars 29 and 32 are arranged to form water channel forming body 9. is doing.

  A sectional view taken along line VV in FIG. 3 is shown in FIG. 8, and further details of the water channel formation body 9 will be described. As described above, the water channel formation body 9 is supported by the fixed legs 33 and disposed inside the case 14 of the power conversion device 100. In addition, the support to the power converter 100 of the water channel formation body 9 may be a component that forms an outer shell such as the cover 1 depending on the arrangement state of the components and the shape of the power converter 100.

  A capacitor module 35, a placement resistor 24, a resistor 25, a high voltage leak detection board 26, a first power module 140, a second power module 141, and both power modules are provided around the waterway case 23 serving as a base. U-phase AC bus bars 27 and 30, V-phase AC bus bars 28 and 31, and W-phase AC bus bars 29 and 32, which are circuits for supplying the output AC current to the rotating electrical machine, are arranged. It is fixed to the terminal block 38 via the current sensor 19 in the box 8.

  The water channel case 23 is provided with an opening. The opening is configured so that the metal base 39 constituting a part of the first power module 140 and the second power module 141 is fixed to the water channel case 23 using a screw or the like, and is closed so that the cooling water is supplied. It becomes the water channel 22 which can be flowed.

  The cooling water is a cooling water as shown in FIG. 5 in order to cool the heat generated by the first power module 140 and the second power module 141 having a plurality of power semiconductor elements and other components requiring cooling. It is introduced from the inlet pipe 15 and discharged from the cooling water outlet pipe 16.

  Incidentally, cooling fins 36 are formed on the metal base 39 in order to improve the cooling efficiency. As the main configuration of the cooling fin 36, a straight fin in which a plurality of linear protrusions are arranged in parallel, a pin fin in which a large number of pin-like fins are arranged, or the like is used.

  Further, as a means for improving the cooling efficiency, a gap 34 is provided between the case 14 of the power conversion device 100, the water channel 22 of the water channel forming body 9, and the first power module 140 and the second power module 141. Yes.

  The effect of providing a gap between the water channel 22, the first power module 140, and the second power module 141 will be described later.

  Next, the usage environment of the power conversion device 100 and the arrangement when the vehicle is mounted are shown in a perspective schematic view of the vehicle engine room portion of FIG. In the present embodiment, the power conversion device 100 is disposed directly above the engine 117 in the engine room of the vehicle 111. Further, in the engine room, there are a power conversion device 100, an engine 117, a cooling water pump 190, a radiator 191, a cooling water pipe 198, a generator 199, etc., and the vehicle has a front wheel 112, a front wheel axle 114, power transmission. Mechanisms for driving the vehicle such as the mechanism 116 and the transmission 195 are arranged. Of course, in addition to these mechanisms, a mechanism for driving a plurality of vehicles is arranged in the vehicle 111, but the illustration is omitted here.

  Inside the engine room is a mechanism for driving the vehicle, especially the radiant heat generated by the driving of the engine 117, and the outside air temperature is particularly high outside the vehicle. Becomes too hot. The power conversion device 100 disposed immediately above the engine 117 is strongly affected by the radiant heat emitted from the engine 117, and the ambient temperature of the power conversion device 100 becomes a high temperature environment equivalent to the radiant heat.

  Especially in such a use environment, in order to efficiently cool electronic components that generate heat due to the operation of electronic components that are restricted in use in high temperature environments and power modules themselves, and become hot. Therefore, it is necessary to provide a power conversion device having higher cooling performance.

  As a method for ensuring high cooling performance, it is possible to receive a supply of a cooling medium such as cooling water from the outside, but in this embodiment, as described above, a water channel forming body having a water channel through which cooling water flows is provided, By placing electronic components that require cooling in contact with the cooling water, each function can be achieved by absorbing the heat generated by itself and the radiant heat generated when the engine is driven or immediately after it is stopped, and cooling the electronic components. Secured. In addition, an efficient cooling function is ensured by bringing the structural parts that are preferably used avoiding high temperatures such as electronic parts and resin parts having a low heat-resistant temperature by bringing them into contact with cooling water. In this case, the structural components are placed in direct contact with the cooling water or indirectly through a cooling medium such as a base of a metal (copper or aluminum) with high heat conductivity or a cooling gel. It is preferable to place the components in contact.

  However, the power conversion device 100 is disposed immediately above the engine 117, and is strongly influenced by the radiant heat from the engine 117, so that the power conversion device 100 is supplied to the power conversion device 100 in a use environment where the power conversion device 100 is at a high temperature. The cooled cooling water is also affected by the radiant heat and becomes a high temperature equivalent to the ambient temperature of the power conversion device 100, and the cooling performance is lowered. There is a possibility of deteriorating the function and deterioration of the product.

  In order to solve this problem, in this embodiment, as shown in FIG. 8, the case 14 of the power conversion device 100, the water channel 22 of the water channel forming body 9, the first power module 140, and the second power module 141. By providing the gap 34 between them, the influence of the ambient temperature from the high temperature can be cut off, and the cooling water at a low temperature can be circulated in the water channel to maintain high cooling performance and to ensure the function of the power conversion device. .

  Details of the effect of the present embodiment in which a gap is provided between the case 14 and the water channel 22 and between the first power module 140 and the second power module 141, the analysis by the following calculation and the power conversion device in a high temperature use environment The temperature measurement result will be described. In the present embodiment, description will be made on the assumption that the temperature in the engine room is around 110 ° C. and the cooling water supply temperature is 75 ° C.

  Here, the amount of heat transfer and heat resistance transferred to the water when heat is applied to the outer shell side of the case where the outer shell and water are in contact with the outer shell and the case where the outer shell and water are in direct contact are derived. The effect of heat insulation by providing a gap from the difference will be described with reference to FIG.

  The details of the calculation conditions of the heat transfer amount (Q) and the thermal resistance (R) and the calculation results 123, 124, and 125 are shown as 126 in a shape of a rectangular parallelepiped under each condition. Moreover, the calculation formulas of the heat transfer amount (Q) and the thermal resistance (R) are shown in the formulas (1) and (2), respectively.

Ａ：幅（ｍ）、Ｂ：奥行（ｍ）、ｉ：複合壁要素（ｉ＝１〜ｎ）、ｋ_i：ｉ要素の熱伝導率（Ｗ／ｍ℃）、Ｌ_i：ｉ要素の長さ（ｍ）、ｎ：複合壁の個数（最大５）、Ｑ：伝熱量（Ｗ）、Ｔ₁：左面温度（℃）、Ｔ_n+1：右面温度（℃）、Ｒ：熱抵抗（℃／Ｗ）

A: width (m), B: depth (m), i: composite wall element (i = 1 to n), k _i : thermal conductivity of i element (W / m ° C.), L _i : length of i element (M), n: number of composite walls (maximum 5), Q: heat transfer (W), T ₁ : left side temperature (° C), T _{n + 1} : right side temperature (° C), R: thermal resistance (° C) / W)

  Condition 1 123: a rectangular parallelepiped in which L1 = a 3 mm long aluminum outer shell, L2 = 30 mm long air, L3 = 2 mm long water channel forming body, and L4 = 50 mm long water . The width A and the depth B are 10 mm.

  Condition 2 124: L1 = a 3 mm long aluminum outer shell, L2 = 5 mm long air, L3 = 2 mm long water channel forming body, and L4 = 50 mm long water in contact with a rectangular parallelepiped. The width A and the depth B are 10 mm.

  Condition 3 125: a rectangular parallelepiped in which L1 = a 3 mm long aluminum outer shell and L4 = 50 mm long water contact. The width A and the depth B are 10 mm.

  The water temperatures are T2 = 75 ° C. and outer shell temperature T1 = 110 ° C., respectively. The width A and the depth B are 10 mm.

  When the numerical values of the respective conditions are applied to the calculation formula of the heat transfer amount (Q) and the calculation formula of the thermal resistance (R) and the conditions 1 to 3 are compared, the heat transfer amount (W) of the condition 2124 with respect to the result of the condition 1123 And the ratio of thermal resistance (° C / W) are about 21.4 times and 5.7 times, respectively, and the ratio of heat transfer amount (W) and thermal resistance (° C / W) of Condition 3 125 is about 467 times, respectively. It is about 1863 times.

  In view of this, it can be said that the heat insulation effect of interposing a gap between the outer shell and water is high, and that the heat insulation effect increases as the width of the gap increases.

  Furthermore, it demonstrates from the temperature measurement result of the power converter device in a high temperature use environment.

  The temperature measurement conditions will be described with reference to FIG. Cooling water of 75 ° C. (temperature at the time of charging) is circulated through the water channel 22 of the water channel forming body 9 at a constant flow rate, and further, a power of 130 A is applied to each of the first power module 140 and the second power module 141. The conversion device 100 is put into a constant temperature bath 150 having an environmental temperature of 110 ° C. and is left until the temperature inside the bath is completely saturated. At that time, various thermocouples (thermocouple (water channel inlet side) 143, thermocouple (water channel formation bottom surface) 144, thermocouple (case bottom surface) 145, thermocouple (water channel outlet side) attached to each component of the power converter 100 ) 146, thermocouples (power modules) 147 and 148), the temperature of the bottom of the power module, case, water channel, and water channel forming body is measured, and the measurement result is monitored by the temperature measuring device 149.

  The effect of the present embodiment by providing a gap in the outer shell and the cooling water channel will be described with reference to FIG. 10 showing the temperature measurement result of the power converter in a high-temperature use environment. The temperature at the bottom of the case under the above environmental temperature condition is 103 ° C., and there is a tendency of temperature increase due to the influence from the environmental temperature 110 ° C. On the other hand, the temperature of the bottom surface of the water channel forming body provided with a gap of 29 mm from the bottom surface of the case is 98 ° C., and the temperature of the cooling formation body with respect to the case bottom temperature is −5 ° C. It is suppressed by the effect of voids.

  In addition, the temperature of the cooling water at the inlet side of the water channel in which a gap is provided with respect to the bottom surface of the case is 77 ° C., the temperature of the cooling water at the outlet side is 81 ° C., and the influence from the internal saturation temperature 110 ° C. No. Furthermore, the power module temperature that generates heat by itself and reaches the maximum temperature of 125 ° C. is suppressed to 108 ° C. in the heating element portion, and the cooling effect by the cooling water is sufficiently ensured.

  From the above, a certain gap (at least the high temperature outer shell and the cooling water channel are not in contact with each other, and the air is affected by the high temperature of the outside air temperature, and the water channel forming body is not in contact with air. It is an effective means for suppressing the cooling water and the cooling formed body from becoming high temperature and ensuring excellent cooling performance.

  The gap is preferably as large as possible. However, in order to provide a power converter having a small size and a low profile, it is preferable that the gap is at least 25 mm in view of arranging the components in the gap. Moreover, since the space | gap arrange | positioned in the position facing the outer shell which becomes high temperature becomes a high temperature environment similar to an outer shell, it is desirable to arrange | position especially these components excellent in heat resistance.

  In the present embodiment, as described above, the heat resistance mainly in the case 14 and the water channel 22 and the gap 34 provided between the first power module 140 and the second power module 141 as shown in FIG. Excellent electronic components are placed.

  The specific heat resistance temperature of the electronic component is such that the heat resistance temperature of the current sensor 19, the resistor 24, and the resistor 25 is 125 ° C., and the heat resistance temperature of the high voltage leak detection substrate 26 is 110 ° C. It can be said that the parts are arranged.

  In addition, as shown in FIG. 13, you may arrange | position the current sensor 19 arrange | positioned in the terminal block box 8 in the space | gap groove 34 instead of the said component. In this case, it may not be adjacent to the terminal block 38 in the terminal block box 8.

  In this way, by using the air gap 34 and arranging components having excellent heat resistance, the power converter can be reduced in height and size.

  Furthermore, as shown in FIG. 12, the oil pump power module 142, the control circuit board 3, and the oil pump control circuit board 6 are provided with a metal base 5 on the back surface of the water channel forming body 9 provided with the gap 34. It arrange | positions in the state which contacted the water channel provided in the water channel formation body 9 via. These components are introduced from the cooling water inlet pipe 15 and cooled by the cooling water discharged from the cooling water outlet pipe 16.

  As described above, according to the above-described embodiment, it is possible to provide a power conversion device that does not impair the cooling performance even when used in a high-temperature environment. Furthermore, the configuration in the power conversion device can be efficiently achieved with one cooling channel. It is possible to cool the entire part. Thereby, a small power converter can be provided.

  As mentioned above, although one Example of this invention was described in detail, this invention is not limited to the above-mentioned Example, It can change suitably within the range of technical thought. For example, in the above-described embodiment, the power module is designed to be cooled and brought into contact with the water channel, but may be brought into contact with the water channel to cool other components.

  In addition, the position where the air gap is arranged is between the case affected by temperature from the outside and the water channel and the power module, but is not limited to the case, other parts forming the outer shell such as a cover, You may arrange | position in the location which self-heats in components and becomes high temperature, and influences surrounding components.

  Furthermore, in order to ensure the cooling performance, not only the gap but also a cooling medium such as a cooling gel or a heat radiation sheet may be arranged in the gap.

DESCRIPTION OF SYMBOLS 1 Cover 2, 10, 11, 17 Electromagnetic wave shielding board 3 Control circuit board 5 Base 6 Control circuit board for oil pumps 8 Terminal block box 9 Water channel formation body,
12 High-voltage DC connector 13 Oil pump control connector 14 Case 15 Cooling water inlet piping 16 Cooling water outlet piping 18 DC capacitor module 19 Current sensor 20 Terminal block cover 21 Terminal block case 22 Water channel 23 Water channel cases 24 and 25 Resistor 26 High voltage leak Detection board 27, 30 U-phase AC bus bar 28, 32 W-phase AC bus bar 29, 31 V-phase AC bus bar 33 Fixed leg 34 Air gap 35 Capacitor module 36 Cooling fin 38 Terminal block 39 Metal base 100 Power converter 110 Hybrid electric vehicle 111 Vehicle 112 Front wheel 113 Rear wheel 114 Front wheel axle 115 Rear wheel axle 116 Power transmission mechanism 117 Engine 123 Calculation result 1 of heat transfer amount and thermal resistance
124 Calculation 2 of heat transfer and thermal resistance
125 Calculation of heat transfer and thermal resistance 3
126 Configuration diagram of heat transfer amount and thermal resistance calculation 127, 128 Drive circuit board 129 Oil pump drive circuit board 130 General control device 131 Transmission control device 132 Battery control device 133 Engine control device 134 Communication line 135 DC / DC converter device 136 High pressure Battery 137 Low-voltage battery 140 First power module 141 Second power module 142 Oil pump power module 143 Thermocouple (water channel inlet side)
144 Thermocouple (bottom of water channel formation body)
145 Thermocouple (case bottom)
146 Thermocouple (Waterway exit side)
147,148 Thermocouple (Power Module)
149 Temperature measuring device 150 Constant temperature bath 190 Cooling water pump 191 Radiator 192 Oil pump driving rotating electrical machine 193 First rotating electrical machine 194 Second rotating electrical machine 195 Transmission 198 Cooling water piping 199 Generator

Claims (3)

A power conversion device used in a hybrid vehicle driven by an engine driving force and a motor driving force,
A water channel former that forms a water channel for flowing a cooling medium;
A power module having a power semiconductor element for converting a direct current into an alternating current, and fixed to the water channel forming body;
A smoothing capacitor module for smoothing the DC current;
An electronic circuit component having a heat resistant temperature greater than the heat resistant temperature of the power semiconductor element;
A housing for housing the power module, the smoothing capacitor module, the water channel formation body, and the discharge circuit component;
The power converter is disposed such that a predetermined surface of the outer wall of the housing faces the engine,
The water channel forming body has a protruding portion protruding from a predetermined surface of the water channel forming body, and is fixed to the inner wall side of the predetermined surface of the housing through the protruding portion,
The power conversion device, wherein the electronic circuit component is disposed in a space formed by the protruding portion between the water channel forming body and the housing, and is fixed to the predetermined surface side of the water channel forming body. The power conversion device according to claim 1,
The power converter according to claim 1, wherein the electronic circuit component is a discharge resistor for discharging a charge stored in the smoothing capacitor module. The power conversion device according to claim 1,
An AC bus bar that transmits the AC current output from the power module and is wired so as to pass through the space,
The electronic circuit component is a current sensor for detecting a current value for energizing the AC bus bar, and the current sensor is a power conversion device arranged in the space.

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