JP5174873B2 - Power converter and elevator - Google Patents

Description

  The present invention relates to a power conversion device including a forward conversion circuit (converter) and an inverse conversion circuit (inverter), and an elevator driven by the power conversion device.

  In recent years, a variable speed drive for an elevator or the like has a method in which an AC commercial power source is converted into DC by a converter, and smoothed DC power is converted into AC of variable frequency via an inverter, and the motor is driven at a variable speed. It has become common.

  Here, as a heat dissipation structure of the converter and the inverter, in the case where the converter is configured only by a diode, in Patent Document 1, the converter side with a small loss is a heat radiation fin, and only the inverter side with a large loss is transported by a heat pipe. The configuration of the heatsink used.

  On the other hand, for elevators for high-rise buildings etc., converters and circuit configurations are often the same as inverters for potential energy regeneration, and all use semiconductor modules composed of semiconductor switching elements. It is. Therefore, in Patent Document 2, the number of components is reduced by attaching a semiconductor module constituting a converter on one side of a radiator and a semiconductor module constituting an inverter on the opposite side.

  Moreover, as another example in which semiconductor modules are attached to both sides of the heat receiving part of the radiator, as in Patent Document 3, a semiconductor module constituting an inverter is provided on one side, and a semiconductor module for a snubber circuit with a small loss is provided on the opposite side. The number of parts is reduced compared to the case where the semiconductor module for the snubber circuit is replaced with another heat radiator.

  On the other hand, as a method of reducing the loss of the semiconductor module, there is a method of reducing the switching loss by switching only two phases out of the three phases and leaving the remaining one phase on or off (two-phase modulation). . In the two-phase modulation, when the output voltage is low, a pulse with an extremely narrow width is generated, so there is a concern that the semiconductor switching element does not actually operate and current distortion occurs. There is a method of switching between phase modulation and two-phase modulation.

Japanese Patent Laid-Open No. 2007-197094 Japanese Patent Laid-Open No. 2002-84766 JP 2001-24123 A JP 2007-110780 A

  However, in the case of cooling using a heat pipe, in the elevator drive, when accelerating from a stop state, the motor output determined by the product of torque and angular frequency is small, so the converter current is small and the loss is low. Since a large current is required to generate a large torque on the inverter side, the loss of the semiconductor module increases. At this time, depending on the situation, the water inside the heat pipe which is a heat transport means may not boil, and the base temperature of the semiconductor module rises transiently. Thereafter, when the acceleration period ends, the current decreases and the loss is reduced, so that the temperature rise is suppressed. There is concern that cracks may occur in the solder between the semiconductor module base plate and the insulating substrate inside the module due to repeated transient temperature rise, thereby reducing the life of the semiconductor module. Therefore, in order to absorb this transient temperature rise, it is necessary to increase the heat capacity of the heat receiving portion from the attachment portion of the heat receiving portion to which the semiconductor module is attached to the heat pipe. However, in that case, there is a problem that the device size of the radiator is increased.

  Here, the configuration of Patent Document 1 cannot be applied to a converter using a semiconductor switching element because the heat dissipation performance is insufficient.

  Moreover, in patent document 2, sufficient examination is not made about the structure of a heat radiator.

  Moreover, in the structure of patent document 3, the problem of the crack by the transient temperature rise as mentioned above arises.

  Even when two-phase modulation is performed on the inverter side as in Patent Document 4, current distortion becomes large in an extremely low speed region, so that two-phase modulation cannot be performed. Therefore, since there is a period during which two-phase modulation cannot be performed, there is a period during which loss cannot be reduced, and the problem of cracks due to repeated transient temperature rise cannot be prevented.

  The problem to be solved by the present invention is to reduce a transient temperature rise of a semiconductor module in a power converter without increasing the size of the device.

  In addition, other problems other than the above-described problems will be made clear from the entire description of the present specification or the drawings.

In order to solve the above problems, in the present invention, a first semiconductor module constituting at least a part of a converter and a second semiconductor module constituting at least a part of an inverter are transported with a phase change. It is attached to the heat receiving part of the radiator using the means, and the heat capacity per unit area of the heat receiving part from the first semiconductor module to the heat transporting means, from the second semiconductor module to the heat transporting means. The heat capacity per unit area of the heat receiving part is increased.
At this time, at least one heat pipe is used as the heat transport means, and the average length of the perpendicular drawn from the center of the cross section of each heat pipe to the contact surface between the first semiconductor module and the heat receiving portion Thus, the average length of the perpendicular drawn from the center of the cross section of each heat pipe to the contact surface between the second semiconductor module and the heat receiving portion is increased.
Alternatively, the heat receiving portion from the second semiconductor module to the heat transport means is made of a material having a larger specific heat than the specific heat of the heat receiving portion from the first semiconductor module to the heat transport means.
Alternatively, the surface on which the first semiconductor module is mounted and the surface on which the second semiconductor module is mounted on the radiator are on opposite sides of the heat transporting means.
Alternatively, at least one heat pipe is used as the heat transporting means, and the first contact surface between the first semiconductor module and the heat receiving portion passes through the center of the cross section of the heat pipe and the longitudinal direction of the heat pipe. A second contact surface between the second semiconductor module and the heat receiving portion passes through the center of the cross section of the heat pipe with respect to the first region surrounded when projected onto a plane parallel to the surface of the heat pipe. The volume of the second region surrounded when projected onto a plane parallel to the longitudinal direction is larger.

  The above-described configuration is merely an example, and the present invention can be modified as appropriate without departing from the technical idea. Further, examples of the configuration of the present invention other than the above-described configuration will be clarified from the entire description of the present specification or the drawings.

  With the above-described configuration, a transient temperature rise of the semiconductor module of the power conversion device can be suppressed without enlarging the device so that the life of the semiconductor module can be extended. Other effects of the present invention will become apparent from the description of the entire specification.

The schematic structure of the power converter device in Example 1 of this invention is shown. The speed ratio v / Vo and loss ratio Q2 / Q1 with respect to the rated speed in Example 1 of the present invention will be described. The circuit structure of the power converter device of this invention and the schematic structure of the elevator driven by it are shown. The operation of the elevator of the present invention will be described. The schematic structure of the power converter device in Example 2 of this invention is shown. The schematic structure of the power converter device in Example 3 of this invention is shown. The schematic structure of the power converter device in Example 4 of this invention is shown. The detailed structure of the heat receiving part of the heat radiator in Example 4 of this invention is shown. The schematic structure of the power converter device in Example 5 of this invention is shown.

  Embodiments of the present invention will be described with reference to the drawings. In each drawing and each embodiment, the same or similar components are denoted by the same reference numerals, and description thereof is omitted.

  First, FIG. 3 shows a circuit configuration of the power converter of the present invention and a schematic configuration of an elevator driven by the circuit configuration. The power conversion apparatus shown in FIG. 3 uses a semiconductor switching element (here, a representative IGBT is described as an example) for an alternating current input from a power supply 8 that is an alternating-current commercial power supply having a constant frequency through a reactor 81. 111 to 132 (111, 112, 121, 122, 131, 132) is converted to direct current by a PWM forward conversion circuit (first conversion circuit) (converter), and the direct current smoothed by the smoothing capacitor 3 is converted to direct current. Inverter circuit (second converter circuit) (inverter) composed of semiconductor switching elements (IGBTs) 211 to 232 (211, 212, 221, 222, 231, 232) is converted into a variable frequency alternating current motor Arbitrary power is supplied to 90. Then, the sheave 91 is rotated by the motor 90 and the car 92 and the counterweight 93 suspended by the rope 94 are moved up and down.

  FIG. 4 shows the operation of the elevator of the present invention. Here, FIG. 4A shows the time change of the speed of the elevator during powering operation, FIG. 4B shows the current amplitude value of the converter, and FIG. 4C shows the current amplitude value of the inverter. . It accelerates from time To which is a stop state, and becomes rated speed Vo at time T3. In the initial stage of acceleration (until time T1), the jerk (time differentiation of acceleration) is constant, the acceleration is constant from time T1 to T2, and the jerk (negative value) is constant from time T2 to T3 to improve riding comfort. ing. Then, after traveling at a constant speed until time T4, the vehicle decelerates and arrives at the target floor at time T5. Although the time is not shown in the figure, the acceleration is changed at the beginning and the end also during deceleration to improve the ride comfort.

  As shown in FIG. 4B, the converter current increases with acceleration and reaches a maximum at time T2, the current decreases at the constant speed from time T3 to T4, and further decreases during deceleration. As shown in FIG. 4C, the inverter current increases from time To to T1 and continues to be large until time T2. The current decreases from time T2 and becomes a current necessary for traveling at the rated speed Vo at time T3. In general, the rated capacity of the motor is determined by the current at this time, and the current during acceleration is often two to three times as large as the rated current at this time.

  In FIG. 1, the schematic structure of the power converter device in Example 1 of this invention is shown. 1A is a side view, and FIG. 1B is a view taken along the line AA ′. Here, the power conversion device in FIG. 3 is structured in one housing 4, the semiconductor switching elements 111 to 132 constituting the converter are one semiconductor module 10, and the semiconductor switching elements 211 to 232 constituting the inverter are In this example, one semiconductor module 20 is configured. Both the semiconductor modules 10 and 20 are attached to both surfaces of the heat receiving part 52 of one radiator 5 as shown in FIG. The heat radiator 5 transports heat from the semiconductor modules 10 and 20 upward in the figure by the heat pipe 51 and dissipates heat by the heat radiation fin by the wind taken from the air inlet 61 by the fan 6. The air that has exited the heat radiating fins passes through the gap between the rear surface of the housing 4 and the radiator 5 by the air guide duct 62 and exits from the exhaust port 63 on the upper surface of the housing. In addition, the heat pipe 51 is a kind of heat transport means accompanied by a phase change, and water is contained in the heat pipe 51, for example. And the heat radiator 5 has the structure provided with the heat receiving part 52 around the heat transport means with a phase change.

  Peripheral circuits 71 and 72 such as a drive circuit are connected in the vicinity of both semiconductor modules 10 and 20, and the smoothing capacitor 3 is disposed below the radiator 5. Here, the wiring conductors between the semiconductor modules 10 and 20 and the smoothing capacitor 3 are not shown for simplification of the drawing.

  In the heat receiving part 52, the thickness from the heat pipe 51 to each surface satisfies D1 <D2 when D1 is the side where the converter-side semiconductor module 10 is attached and D2 is the side where the inverter-side semiconductor module is attached. By doing so, the heat capacity per unit area of the heat receiving part 52 from the converter-side semiconductor module 10 to the heat pipe 51 per unit area of the heat receiving part 52 from the inverter-side semiconductor module 20 to the heat pipe 51 is reduced. The heat capacity can be increased. On the converter side, a constant frequency alternating current is converted to direct current, so the transient temperature rise does not occur very much. On the inverter side, the direct current is converted to a variable frequency alternating current, so the transient temperature rise is repeated. Likely to happen. However, even if heat transfer cannot be sufficiently performed by the heat pipe 51 due to a short-term transient temperature rise or the like, since the heat capacity per unit area of the heat receiving portion 52 is large, the transient temperature rise can be absorbed. Since the temperature rise of the module can be reduced, the problem of cracking in the solder can be avoided, and the thickness of the heat receiving portion 52 on the inverter side where problems are likely to occur is made thicker than that on the converter side. There is an advantage that the size of the apparatus is not so large.

  FIG. 1 (c) is a modification of FIG. 1 (a). FIG. 1 (c) is different from FIG. 1 (a) in that the thick inverter side of the heat receiving portion 52 is the intake side (left in the figure). The thin converter side of the heat receiving portion 52 is arranged opposite (right side in the figure). In this case, the peripheral circuit 72 on the inverter side protrudes to the left in the drawing from the fan 6, and the heat radiator is shifted to the back side accordingly. As a result, the width DB2 of the air path to the exhaust port becomes smaller than the width DB1 in the case of FIG. 1A, the pressure loss increases, and the wind speed decreases. Therefore, in the case of front side exhaust with front intake, it is preferable to increase the thickness of the heat receiving portion with the semiconductor module 20 on the inverter side on the back side as shown in FIG. However, there is an advantage also in the case of FIG. 1C, and by increasing the heat receiving portion 52 on the side where the fan 6 is attached, the amount of protrusion of the fan 6 in the depth direction is reduced, and in FIG. 1 (c) is not shown in FIG. 1 (c), but the dimension in the depth direction of the casing 4 of the power converter is equivalent to that of FIG. 1 (a). It can be made smaller.

  The loss (thermal load) generated by the converter-side and inverter-side semiconductor modules during the acceleration period of FIG. 4 is almost linearly related to the respective current values, whereas the converter increases from time To to T2. The inverter increases rapidly from time To to T1. Therefore, the temperature rise is suppressed by increasing the heat capacity by increasing the thickness of the heat receiving portion 52. On the other hand, there is a concern that the weight of the radiator 5 is increased by increasing the thickness of the heat receiving portion 52. Therefore, it is not necessary to increase the heat capacity of the heat receiving part on the converter side where the rate of increase in current amplitude is not large compared to the inverter. Therefore, by increasing only the inverter side, the increase in the weight of the radiator 5 is minimized. ing.

  FIG. 2 shows the relationship between the ratio v / Vo of the speed v at the time t to the rated speed (speed at constant speed) Vo and the ratio of the inverter-side loss Q2 to the converter-side loss Q1 at the time t in a general elevator. Shown in The degree of transient temperature rise differs depending on the heat capacity and thermal resistance of the radiator 5, but after the time point when the speed v is accelerated to about half of the rated speed Vo (v / Vo is 0.5 or more), the heat pipe 51 Heat transport also becomes steady, and thereafter, the temperature rise suppression effect by increasing the heat capacity of the heat receiving portion 52 is reduced. Therefore, if the ratio D2 / D1 ≧ 1.2 of the thickness of the heat receiving portion is set, it can be said that there is an effect by increasing the heat capacity of the heat receiving portion.

  In FIG. 5, the schematic structure of the power converter device in Example 2 of this invention is shown. Here, a case where the pair of upper and lower semiconductor switching elements for one phase in FIG. 3 is configured by one semiconductor module as in the case where the current is larger than in the example of FIG. 1, and the semiconductor switching element 111 in FIG. The semiconductor module 11 is constituted by 112, the semiconductor module 12 is constituted by semiconductor switching elements 121 and 122, and the semiconductor module 13 is constituted by semiconductor switching elements 131 and 132. Similarly, on the inverter side, the semiconductor module 21 is constituted by the semiconductor switching elements 211 and 212, the semiconductor module 22 is constituted by the semiconductor switching elements 221 and 222, and the semiconductor module 23 is constituted by the semiconductor switching elements 231 and 232, respectively. .

  As shown in FIG. 5 (a), one phase each on the converter side and the inverter side is attached to both surfaces of the heat receiving portion 52 of the same radiator 5, and is a view taken along the line AA 'shown in FIG. 5 (c). As shown, the heat receiving portions 52 of the three radiators 5 are arranged side by side to constitute a power conversion device. Further, the smoothing capacitors 31 to 33 are also divided into phases, and these are connected by wiring conductors (not shown).

  As shown in FIG. 5A, the heat receiving portion thickness D2 for attaching the inverter-side semiconductor module 23 is made larger than the heat receiving portion thickness D1 for attaching the converter-side semiconductor module 13 as in the case of the first embodiment. This suppresses the temperature rise during the elevator acceleration period.

  Here, the air that has entered from the air inlet 61 by the fan 6 passes through the heat radiating fins of the radiator and passes through the air outlet 63 on the back side as it is (structure of front side intake and back side exhaust). In FIG. 5A, the heat receiving part on the inlet side (left side in the figure) is thickened and the semiconductor module 23 on the inverter side (the same applies to 21 and 22) is attached. The heat receiving part on the exhaust side (right side in the figure) is The semiconductor module 13 on the converter side (same for 11 and 12) was attached.

  On the other hand, FIG. 5B shows a case where the converter side is attached to the intake port side (left side in the figure) and the inverter side is attached to the exhaust port side (right side in the figure). In FIG. 5B, since the thickness of the heat receiving part on the back side is large, the peripheral circuit 723 on the inverter side protrudes from the depth of the radiator 5. Therefore, the housing depth DC2 in the case of FIG. 5B is larger than DC1 in comparison with the housing depth DC1 in the arrangement of FIG. 5A, and is not suitable for downsizing. Therefore, as shown in FIG. 5A, it is preferable to attach the inverter-side semiconductor module by thickening the heat receiving portion 52 on the inlet side (left side in the drawing). From another viewpoint, it is preferable to increase the thickness of the heat receiving portion 52 on the side where the fan 6 is attached.

  In FIG. 6, the schematic structure of the power converter device in Example 3 of this invention is shown. The same parts as those in FIG. 1 are denoted by the same reference numerals and description thereof is omitted, and only different parts will be described. Here, two rows of heat pipes 511 to 515 are arranged in the radiator 5. As shown in FIG. 6C, which is a view taken along the line B-B 'of FIG. 6A, there are two heat pipes 512 and 514 on the side close to the semiconductor module 10 on the converter side. A straight line connecting the centers of the cross sections is L1. On the other hand, there are three heat pipes 511, 513, and 515 on the inverter side near the semiconductor module 20, and a straight line connecting the centers of their cross sections is L2.

As shown in the figure, when the length of the perpendicular from each heat pipe to the surface of the heat receiving part 52 is D11 to D52, the average value D1 to the contact surface of the semiconductor module 10 on the converter side is an equation: It is represented by 1. On the other hand, the average value D2 of the length to the contact surface of the semiconductor module 20 on the inverter side is expressed by Equation 2.
(Formula 1)
D1 = (D11 + D21 + D31 + D41 + D51) / 5
(Formula 2)
D2 = (D12 + D22 + D32 + D42 + D52) / 5

  Here, by setting D1 <D2, the heat capacity for transient heat generation from the semiconductor module 20 on the inverter side is increased to suppress the temperature rise.

  In FIG. 7, the schematic structure of the power converter device in Example 4 of this invention is shown. The same parts as those in FIG. 1 are denoted by the same reference numerals and description thereof is omitted, and only different parts will be described. In this case, the heat pipes 511 to 513 are not vertically but inclined. The direction of intake and exhaust of the fan 6 is not horizontal, but is inclined so that the exhaust direction is obliquely upward. Thereby, the pressure loss until the exhaust from the radiation fin of the radiator 5 in the case of top exhaust with front intake reaches the exhaust outlet 63 provided on the upper surface of the housing 4 of the apparatus can be reduced.

  The converter-side semiconductor module 10 and the inverter-side semiconductor module 20 are attached to the same surface of the heat receiving portion 52 of the radiator 5. The smoothing capacitor 3 is connected to the vicinity of the semiconductor modules 10 and 20 by a printed board 70. FIGS. 7B and 7C show cross sections of the heat receiving portion 52 of the radiator 5 at substantially the center of the semiconductor module 10 on the converter side and the semiconductor module 20 on the inverter side, respectively. 7B is a cross-sectional view taken along the line AA ′ of FIG. 7A, and FIG. 7C is a cross-sectional view taken along the line BB ′ of FIG. 7A. The distance from the inverter-side semiconductor module 20 to the heat pipes 511 to 513 is longer than the distance from the converter-side semiconductor module 10 to the heat pipes 511 to 513.

  The detailed structure of the heat receiving part 52 of the radiator 5 is shown in FIG. 8B is a cross-sectional view taken along the line AA ′ of FIG. 8A, and FIG. 8C is a cross-sectional view taken along the line BB ′ of FIG. 8A. The hatched area 1 in FIG. 8 is a part that contributes to the heat capacity for heat from the semiconductor module 10 on the converter side, and the part represented by area 2 in the figure contributes to the heat capacity for heat from the semiconductor module 20 on the inverter side. Part. The region 1 is surrounded when the contact surface between the converter-side semiconductor module 10 and the heat receiving portion 52 is projected onto a plane parallel to the longitudinal direction LP of the heat pipes 511 to 513 through the center of the cross section of the heat pipes 511 to 513. It is an area. The region 2 is surrounded when the contact surface between the inverter-side semiconductor module 20 and the heat receiving portion 52 is projected onto a plane parallel to the longitudinal direction LP of the heat pipes 511 to 513 through the center of the cross section of the heat pipes 511 to 513. It is an area. The volume of the region 2 is increased compared with the volume of the region 1 to suppress a transient temperature rise of the semiconductor module 20 on the inverter side.

  In FIG. 9, the schematic structure of the power converter device in Example 5 of this invention is shown. FIG.9 (b) is an AA 'arrow line view of Fig.9 (a). Here again, the same parts as those in FIG. In this example, the heat receiving portions 521 and 522 of the radiator 5 are made of different materials, and are structured such that the heat pipes 511 to 513 are sandwiched by fastening them with fastening parts 53 (screws or the like). Further, the heat receiving portion 522 on the side where the inverter-side semiconductor module 20 is attached is made of a material having a larger specific heat than the heat receiving portion 521 on the side where the converter-side semiconductor module 10 is attached. For this reason, it is possible to increase the heat capacity with respect to the heat from the semiconductor module 20 on the inverter side, and the temperature rise of the semiconductor module 20 on the inverter side is suppressed.

  The entire heat receiving part of the radiator 5 is made of a material having a large specific heat like the heat receiving part 522 on the side where the inverter-side semiconductor module 20 is attached, thereby suppressing a transient temperature rise of the inverter-side semiconductor module 20. However, since the density of a material having a large specific heat is generally high, the mass of the entire radiator 5 is increased. Therefore, as shown in FIG. 9, the weight of the radiator 5 as a whole is obtained by making only the inverter side a material with a large specific heat and specific gravity (for example, copper) and the converter side with a material with a small specific heat and specific gravity (for example, aluminum). The increase is suppressed.

  As described above, the heat pipe type heat radiator with heat transport means with phase change is taken as an example, and the heat pipe is described as an example in a generally vertical orientation, but when the heat pipe is placed in a nearly horizontal state However, if it is the structure of this invention, the effect which suppresses the transient temperature rise with respect to an inverter side load will be acquired.

  In the first to fifth embodiments, in order to reduce heat due to loss, the number of switching times of the converter-side semiconductor module 10 may be shorter than the number of switching times of the inverter-side semiconductor module 20. desirable. For example, the semiconductor module 10 on the converter side is controlled by two-phase modulation control, and the semiconductor module 20 on the inverter side has at least a period of three-phase modulation control. Specifically, it is desirable that the converter is always controlled by two-phase modulation control, and the inverter is controlled by three-phase modulation control in the low frequency region and by two-phase modulation control in the high frequency region.

  The present invention has been described using the embodiments. However, the configurations described in the embodiments so far are only examples, and the present invention can be appropriately changed without departing from the technical idea. Further, the configurations described in the respective embodiments may be used in combination as long as they do not contradict each other.

DESCRIPTION OF SYMBOLS 3 Smoothing capacitor 4 Case 5 Radiator 6 Fan 8 Power supply 10, 11, 12, 13, 20, 21, 22, 23 Semiconductor module 51,511,512,513,514,515 Heat pipe 61 Inlet 62 Air guide duct 63 exhaust port 71, 72 peripheral circuit 81 reactor 90 motor 91 sheave 92 passenger car 93 counterweight 94 rope

Claims (14)

In a power conversion device having a first conversion circuit that converts alternating current into direct current, and a second conversion circuit that converts direct current converted by the first conversion circuit into variable frequency alternating current,
Having a heat radiator with a heat receiving part around the heat transport means with phase change,
A first semiconductor module that constitutes at least a part of the first conversion circuit and a second semiconductor module that constitutes at least a part of the second conversion circuit are attached to the heat receiving part,
The heat capacity per unit area of the heat receiving portion from the second semiconductor module to the heat transport means is larger than the heat capacity per unit area of the heat receiving portion from the first semiconductor module to the heat transport means. The
Using at least one heat pipe as the heat transport means, the average length of the perpendicular drawn from the center of the cross section of each heat pipe to the contact surface between the first semiconductor module and the heat receiving portion, The power converter according to claim 1, wherein an average length of a perpendicular drawn from a center of a cross section of each heat pipe to a contact surface between the second semiconductor module and the heat receiving portion is larger .   2. The thickness of the heat receiving part from the second semiconductor module to the heat transporting unit is larger than the thickness of the heat receiving part from the first semiconductor module to the heat transporting unit. The power converter characterized by this.   3. The thickness of the heat receiving portion from the second semiconductor module to the heat transport means is 1.2 times the thickness of the heat receiving portion from the first semiconductor module to the heat transport means. The power converter characterized by the above. In a power conversion device having a first conversion circuit that converts alternating current into direct current, and a second conversion circuit that converts direct current converted by the first conversion circuit into variable frequency alternating current,
Having a heat radiator with a heat receiving part around the heat transport means with phase change,
A first semiconductor module that constitutes at least a part of the first conversion circuit and a second semiconductor module that constitutes at least a part of the second conversion circuit are attached to the heat receiving part,
The heat capacity per unit area of the heat receiving portion from the second semiconductor module to the heat transport means is larger than the heat capacity per unit area of the heat receiving portion from the first semiconductor module to the heat transport means. ,
Wherein the relative specific heat of the heat receiving portion from the previous SL first semiconductor module to the heat transfer means, towards the said second semiconductor module of the heat receiving portion to the heat transfer means is a large specific heat material A power converter. 5. The method according to claim 1, wherein a surface on which the first semiconductor module is attached and a surface on which the second semiconductor module is attached are on opposite sides of the heat transporting means. Power converter. In a power conversion device having a first conversion circuit that converts alternating current into direct current, and a second conversion circuit that converts direct current converted by the first conversion circuit into variable frequency alternating current,
Having a heat radiator with a heat receiving part around the heat transport means with phase change,
A first semiconductor module that constitutes at least a part of the first conversion circuit and a second semiconductor module that constitutes at least a part of the second conversion circuit are attached to the heat receiving part,
The heat capacity per unit area of the heat receiving portion from the second semiconductor module to the heat transport means is larger than the heat capacity per unit area of the heat receiving portion from the first semiconductor module to the heat transport means. ,
Power conversion apparatus characterized by a surface for attaching the front Symbol radiator the second semiconductor module and the first a mounting surface semiconductor module is on the opposite side of said heat transfer means.   7. The power converter according to claim 6, wherein the radiator is configured to be cooled by forced air cooling, and the power conversion is performed after the cooling air that has been sucked from the front surface of the power conversion device and has passed through the radiation fins of the radiator is discharged to the back surface side. A power converter having a structure in which air is exhausted from an upper surface of the device, and the surface on which the second semiconductor module is attached is disposed on the back side.   7. The radiator according to claim 6, wherein the radiator is cooled by forced air cooling using a fan, and the second semiconductor module is placed in a heat receiving portion on the side where the fan of the radiator is installed. A power conversion device, wherein the first semiconductor module is attached to a heat receiving portion on the side where no heat sink is installed.   9. The structure according to claim 8, wherein the cooling air that has been sucked in from the front surface of the power conversion device and passed through the radiation fins of the radiator is exhausted from the back surface, and the surface on which the second semiconductor module is attached is the front side. The power converter characterized by arrange | positioning so that it may become. In a power conversion device having a first conversion circuit that converts alternating current into direct current, and a second conversion circuit that converts direct current converted by the first conversion circuit into variable frequency alternating current,
Having a heat radiator with a heat receiving part around the heat transport means with phase change,
A first semiconductor module that constitutes at least a part of the first conversion circuit and a second semiconductor module that constitutes at least a part of the second conversion circuit are attached to the heat receiving part,
The heat capacity per unit area of the heat receiving portion from the second semiconductor module to the heat transport means is larger than the heat capacity per unit area of the heat receiving portion from the first semiconductor module to the heat transport means. ,
Using at least one or more heat pipes as before Symbol heat transporting means, in the longitudinal direction of the first semiconductor module and the first central street the heat pipe of the contact surface section of the heat pipe and said heat receiving portion With respect to the first region surrounded when projected onto a parallel plane, the second contact surface of the second semiconductor module and the heat receiving part passes through the center of the cross section of the heat pipe and is the length of the heat pipe. A power converter characterized in that a volume of a second region surrounded when projected onto a plane parallel to a direction is larger.   The power conversion device according to claim 10, wherein a longitudinal direction of the heat pipe is inclined obliquely with respect to a vertical direction.   12. The method according to claim 1, wherein the number of switching times of the first semiconductor module constituting the first conversion circuit is compared with the number of switching times of the second semiconductor module constituting the second conversion circuit. A power converter characterized by having a short period.   13. The period of the first semiconductor module constituting the first conversion circuit according to claim 12, wherein the first semiconductor module constituting the first conversion circuit is in two-phase modulation control, and the second semiconductor module constituting the second conversion circuit is at least in a period of three-phase modulation control. There is a power converter characterized by that.   14. An elevator using the power conversion device according to claim 1, wherein the first conversion circuit is connected to a power source, and is driven by supplying power from the second conversion circuit to a motor.

Images