Power conversion device and method of manufacturing the same

Abstract

The power conversion device includes a power conversion module, a phase change material, a heat dissipation component, a cooling mechanism and a control mechanism. The semiconductor switch element and the return diode constitute a power conversion circuit. The phase change material is provided on the main surface of the housing. The heat dissipation component includes a heat dissipation surface, and the heat dissipation surface is overlapped on the main surface in a manner of sandwiching the phase change material. The cooling mechanism cools the heat dissipation component. The control mechanism generates a drive signal for driving the power conversion circuit and controls the cooling mechanism. The control mechanism includes a pre-set heating operation. The heating operation can also drive the power conversion circuit in a state where the cooling mechanism is stopped or intermittently operated to generate heat in both the semiconductor switch element and the return diode.

Description

Technical Field

[0001] The present invention relates to a power conversion device using a phase change material and a method for manufacturing the same. Background Art

[0002] Conventionally, there is known a semiconductor device including a thermal interface material (TIM), as described in, for example, Japanese Patent No. 6540612. The TIM reduces the thermal resistance between the semiconductor element and the heat sink. In the above conventional technology, a phase change material is used as the TIM.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent No. 6540612 Summary of the invention

[0006] Problems to be solved by the invention

[0007] The phase change material softens by heating and improves adhesion. By improving adhesion, the contact thermal resistance can be reduced. As a result, heat is efficiently conducted from the power conversion module to the heat dissipation component via the phase change material.

[0008] In order to effectively reduce the contact thermal resistance of the phase change material, it is not preferred to have large heating unevenness in the contact surface between the power conversion module and the heat dissipation component. In this regard, the above-mentioned previous technologies lack research on temperature unevenness when the phase change material is heated, and there is still room for improvement.

[0009] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an improved power conversion device and a method for manufacturing the same in which unevenness in the heating and softening of a phase change material is suppressed.

[0010] Means used to solve problems

[0011] The power conversion device according to the present invention comprises a power conversion module, a phase change material, a heat dissipation component, a cooling mechanism and a control mechanism. The power conversion module comprises a housing having a main surface and a semiconductor switch element and a reflux diode which are accommodated in the housing and arranged in the plane direction of the main surface. The semiconductor switch element and the reflux diode constitute a power conversion circuit. The phase change material is arranged on the main surface of the housing. The heat dissipation component comprises a heat dissipation surface. The heat dissipation surface is overlapped on the main surface in a manner of sandwiching the phase change material. The cooling mechanism cools the heat dissipation component. The control mechanism generates a drive signal for driving the power conversion circuit and controls the cooling mechanism. The control mechanism includes a pre-set heating operation.

[0012] The heating operation may be performed by driving the power conversion circuit while the cooling mechanism is stopped or intermittently operated so that both the semiconductor switching element and the freewheeling diode generate heat.

[0013] The heating operation may be performed in a low power factor DC-AC conversion mode while the cooling mechanism is continuously driven. The low power factor DC-AC conversion mode may drive the power conversion circuit to generate AC power from DC power at a preset target power factor of less than 1.

[0014] The manufacturing method of the power conversion device of the present invention comprises: a process of preparing a power conversion module including a housing having a main surface and a phase change material provided on the main surface; a process of overlapping the heat dissipation surface of the heat dissipation component and the main surface in a manner of sandwiching the phase change material; and a process of performing a heating operation for heating the phase change material in a pre-shipment test of the product. The power conversion module includes a semiconductor switching element and a return diode. The semiconductor switching element and the return diode are housed in the housing and arranged in the planar direction of the main surface. The semiconductor switching element and the return diode constitute a power conversion circuit.

[0015] The step of performing the heating operation may include driving the power conversion circuit to generate heat in both the semiconductor switch element and the freewheeling diode while stopping or intermittently operating a cooling mechanism for cooling the heat dissipating member.

[0016] The heating operation may be performed in a low power factor DC-AC conversion mode while the cooling mechanism for cooling the heat dissipation component is continuously driven. The low power factor DC-AC conversion mode may also drive the power conversion circuit to generate AC power from DC power at a preset target power factor of less than 1.

[0017] Effects of the Invention

[0018] According to the above-mentioned power conversion device and manufacturing method, a heating operation can be performed to heat the semiconductor switch element and the return diode. According to the heating operation, the phase change material is heated and softened in a state where the temperature unevenness in the area near the semiconductor switch element and the return diode on the main surface is suppressed. As a result, it is possible to suppress the occurrence of unevenness in the heating and softening of the phase change material. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural diagram of a power conversion device according to an embodiment.

[0020] Figure 2 It is a diagram showing a power conversion device and a heat dissipation component according to an embodiment.

[0021] Figure 3 It is a top view of the power conversion module according to the embodiment.

[0022] Figure 4 It is a cross-sectional view of a power conversion module according to an embodiment.

[0023] Figure 5 This is a circuit diagram showing an example of a circuit configuration of a power conversion device according to an embodiment.

[0024] Figure 6 It is a diagram showing an example of a test device for the power conversion device according to the embodiment.

[0025] Figure 7 This is a flowchart for explaining a method for manufacturing a power conversion device according to an embodiment.

[0026] Figure 8 This is a flowchart for explaining the heating operation of the power conversion device according to the embodiment.

[0027] Fig. 9 This is a graph for explaining the operation of the heating operation of the power conversion device according to the embodiment.

[0028] Fig.10 : is a table showing changes in the heating operation of the power conversion device according to the embodiment.

[0029] Fig.11 : is a table showing changes in the heating operation of the power conversion device according to the embodiment.

[0030] Fig.12 This is a graph for explaining the operation of the heating operation of the power conversion device according to the modification of the embodiment.

[0031] Fig.13 This is a flowchart for explaining the heating operation of the power conversion device according to the modification of the embodiment.

[0032] Fig.14 This is a flowchart for explaining the heating operation of the power conversion device according to the modification of the embodiment.

[0033] Fig.15 This is a flowchart for explaining the heating operation of the power conversion device according to the modification of the embodiment. DETAILED DESCRIPTION

[0034] Figure 11 is a block diagram of a power conversion device 10 according to an embodiment. The power conversion device 10 includes a power conversion unit 1, a heat sink 50, a cooling mechanism 33, a control mechanism 20, and a temperature sensor 31. The power conversion device 10 accommodates the above-mentioned components in a housing. The housing is also provided with ventilation holes and the like.

[0035] The power conversion unit 1 includes a power conversion circuit 1a and a gate drive substrate 1b. The power conversion circuit 1a is a voltage-type three-phase inverter circuit including three arm circuits. There is no limitation on the specific type of the voltage-type three-phase inverter circuit. The power conversion circuit 1a includes a plurality of Figure 2 The power conversion module 100 described later.

[0036] The cooling mechanism 33 cools the heat dissipation component 50. The cooling mechanism 33 of the embodiment is, for example, an air-cooling cooling fan. As a modified example of the cooling mechanism 33, a refrigerant circulation system may be used instead of the cooling fan for air cooling. The refrigerant circulation system of the modified example may also include a refrigerant passage in contact with the heat dissipation component 50, a radiator provided in the middle of the refrigerant passage, and a circulation pump that circulates the refrigerant in the refrigerant passage. By controlling the speed of the air-cooling cooling fan or the driving speed of the circulation pump, the opening and closing of the cooling mechanism 33 and the cooling amount can be adjusted.

[0037] The control mechanism 20 includes a power conversion control unit 20a and a temperature control unit 20b. The power conversion control unit 20a generates a PWM signal S PWM The temperature control unit 20b transmits the fan control signal S to the power conversion unit 1. In order to control the cooling mechanism 33, the temperature control unit 20b transmits the fan control signal S f The heat is transmitted to the cooling mechanism 33 .

[0038] The control mechanism 20 may be constructed by one or more personal computers. An example of a specific hardware configuration of the control mechanism 20 will be described later.

[0039] The temperature sensor 31 detects the ambient temperature T1 of the power conversion module 100 . A temperature detection signal T1 of the temperature sensor 31 is transmitted to the control mechanism 20 .

[0040] Figure 2 1 is a diagram showing a power conversion device 10 and a heat sink 50 according to an embodiment. In the embodiment, as an example, the heat sink 50 is a heat pipe. Alternatively, the heat sink 50 may be transformed into a heat sink.

[0041] The heat dissipation component 50 has a heat dissipation surface 50a. Three power conversion modules 100 are arranged on the heat dissipation surface 50a. The heat dissipation surface 50a and the main surface 101 overlap in a manner of sandwiching a phase change material 120. This heat conduction layer provided on the heat dissipation surface 50a is also called a thermal interface material (TIM). Various materials are known in TIM, such as grease. In the embodiment, a phase change material is used in the TIM.

[0042] Figure 3 It is a top view of the power conversion module 100 according to the embodiment. Figure 4 It is a cross-sectional view of a power conversion module 100 according to the embodiment. Figure 4 It is along Figure 3 Cross-sectional view along line I-II. Figure 3 and Figure 4 The diagram shows the state of the phase change material 120 before being softened by heating.

[0043] The power conversion module 100 includes a housing 100 a , a substrate 112 accommodated in the housing 100 a , and a semiconductor switch element 110 and a freewheeling diode 111 mounted on the substrate 112 .

[0044] The housing 100a is composed of a resin seal 116 and a heat sink 114. The housing 100a has an upper surface 102, a lower surface 101, and four side surfaces 103. One surface of the heat sink 114 corresponds to the lower surface 101 of the housing 100a. In the embodiment, as an example, the lower surface 101 of the housing 100a is also referred to as a "main surface 101".

[0045] The semiconductor switch element 110 is turned on and off according to the gate drive signal. The semiconductor switch element 110 can be an IGBT, a MOSFET, or a GTO. The semiconductor material of the semiconductor switch element 110 and the return diode 111 can be silicon or a wide-bandgap semiconductor such as SiC.

[0046] exist Figure 3 In the figure, the semiconductor switch element 110 and the reflux diode 111 are shown by dotted lines by viewing the heat sink 114 from the main surface 101 side. Figure 3 As shown, the semiconductor switch element 110 and the freewheeling diode 111 are arranged in a predetermined layout in the plane direction of the main surface 101. In the embodiment, as an example, the housing 100a is a resin-molded sealing resin package. However, as a modified example, the housing 100a may also be a resin box having a cover and a box.

[0047] The power conversion module 100 includes two semiconductor switch elements 110 and three return diodes 111. One power conversion module 100 constitutes one branch circuit. Figure 2 As shown, by providing three power conversion modules 100 , a power conversion circuit 1 a is constructed as a three-phase inverter circuit.

[0048] The phase change material 120 is provided on the main surface 101 of the housing 100a. In the embodiment, the phase change material 120 is made into a small hexagonal piece as an example, and a plurality of phase change materials 120 are arranged on the main surface 101. However, as a modified example, a single phase change material sheet may be attached to the main surface 101. Figure 3 When the main surface 101 is viewed through in this manner, it is preferable that the semiconductor switch element 110 and the freewheeling diode 111 are sufficiently covered with the phase change material 120 .

[0049] The phase change material 120 has the property of softening due to heat. If the adhesion is improved by softening, the contact thermal resistance is reduced. As a result, the thermal conductivity to the heat dissipation component 50 becomes higher, so the heat dissipation can be improved. Since various materials of the phase change material 120 are already well known, a detailed description is omitted.

[0050] Figure 5 1 is a circuit diagram showing an example of a circuit configuration of a power conversion device 10 according to an embodiment. Figure 5 In the figure, it is also shown Figure 1 Circuit elements omitted in .

[0051] DC power is input from a DC power source 30 to DC input terminals P and N of the power conversion device 10. In the embodiment, as an example, the DC power source 30 is a solar panel. The AC output terminals U, V, and W of the power conversion device 10 are connected to a power system 40.

[0052] The power conversion circuit 1 a can perform inverter driving for converting DC power into three-phase AC power and converter driving for converting three-phase AC power into DC power in accordance with a drive signal from the control unit 20 .

[0053] The power conversion device 10 includes a DC side circuit connected to the DC side of the power conversion unit 1 and an AC side circuit connected to the AC side of the power conversion unit 1. The DC side circuit includes a DC side relay 3, a metering current transformer (CT) 8a, and a metering voltage transformer (VT) 8b.

[0054] The AC side circuit includes a transformer 2, a protection relay 4, an AC end relay 5, a reactor 6, a capacitor 7, a metering current transformer (CT) 9a, 9c and a metering voltage transformer (VT) 9b, 9d. The transformer 2 is connected to the AC end of the power conversion unit 1. The reactor 6 is connected in series with the transformer 2. One end of the capacitor 7 is connected between the transformer 2 and the reactor 6, and the other end of the capacitor 7 is connected to a reference potential such as a ground potential. The protection relay 4 is connected in series with the reactor 6. The AC end relay 5 is connected in series with the protection relay 4. The metering current transformer 9a and the metering voltage transformer 9b are provided between the protection relay 4 and the AC end relay 5. The metering current transformer 9c is provided between the AC end of the power conversion unit 1 and the transformer 2. The metering voltage transformer 9d is provided between the connection point between the transformer 2 and the capacitor 7 and the reactor 6. In addition, the DC side circuit and the AC side circuit can have various structures, and an example is shown in the embodiment.

[0055] The control mechanism 20 is a control circuit. The power conversion control unit 20a of the control mechanism 20 includes a PWM control unit 21 and a power control unit 22. The power control unit 22 obtains the DC side current value obtained via the metering current transformer 8a, the DC side voltage value obtained via the metering voltage transformer 8b, the AC side current value obtained via the metering current transformer 9a, and the AC side voltage value obtained via the metering voltage transformer 9b.

[0056] The power control unit 22 transmits a "power control signal" to the PWM control unit 21 based on the acquired parameters. In the embodiment, since the power control unit 22 has an MPPT control mode (maximum power point following control mode) as an example, the power control signal may also be a control command value based on the MPPT control. In addition, the power control signal may also be a charge and discharge control command value based on the active power command value and the reactive power command value.

[0057] The PWM control unit 21 obtains the AC side current value obtained via the measuring current transformer 9c and the AC side voltage value obtained via the measuring voltage transformer 9d. Based on the obtained parameters, the PWM control unit 21 generates a drive signal for the switching element according to the power control signal from the power control unit 22. In the embodiment, the drive signal is a pulse width modulation signal (PWM signal).

[0058] The temperature control unit 20b of the control mechanism 20 includes a cooling control unit 20b1 and a mode control unit 20b2. The temperature control unit 20b receives a temperature detection signal T1 from the temperature sensor 31. The cooling control unit 20b1 switches the cooling control mode of the cooling mechanism 33 (cooling fan) between constant drive (constant ON), intermittent drive (intermittent ON), and stop (OFF).

[0059] The mode control unit 20b2 can instruct the cooling control unit 20b1 on the cooling control mode and the power conversion circuit 1a on the power conversion mode. The mode control unit 20b2 instructs the power conversion circuit 1a to drive in at least one of the "AC-DC conversion mode" and the "low power factor DC-AC conversion mode".

[0060] The AC-DC conversion mode is a mode in which the power conversion circuit 1a is driven to generate DC power from AC power. In the AC-DC conversion mode, since the return diode 111 is used as a rectifier, current flows through the return diode 111. As a result, the return diode 111 can generate heat, and the phase change material 120 can be heated and softened by the heat.

[0061] This AC-DC conversion mode is also referred to as a "charging mode" for convenience in the embodiment. This is because the mode in which the power conversion unit 1 generates DC from AC is generally used as a mode in which DC power is generated from the power system 40 to charge the battery. Figure 6 In the test in the test apparatus 200 described later, the AC-DC conversion mode is used as the charging mode.

[0062] The "low power factor DC-AC conversion mode" is a mode in which the power conversion circuit 1a is driven to generate AC power from DC power at a target power factor Φ that is less than a preset power factor of less than 1. Since the low power factor DC-AC conversion mode performs low power factor power conversion, a relatively large amount of reactive current flows through the power conversion circuit 1a. As a result, the return diode 111 can generate heat, and the phase change material 120 can be heated and softened by the heat.

[0063] The value of the target power factor Φ is not limited, and the target power factor can be set arbitrarily in the range of 0<Φ<1.0. For example, it can also be Φ=0.9, 0.8, 0.7..., 0.2, 0.1, etc. For example, the setting range of the target power factor Φ can also be set. The upper limit target power factor can also be selected from Φ=0.99~0.5, and the lower limit target power factor can also be selected from Φ=0.49~0.01, or the setting range can be defined by an arbitrary upper limit target power factor and an arbitrary lower limit target power factor.

[0064] The low power factor DC-AC conversion mode is also referred to as a "low power factor discharge mode" for convenience in the embodiment. This is because the mode in which the power conversion unit 1 produces AC from DC is used as a mode for discharging power from the battery to the power system 40. Figure 6 In the test in the test apparatus 200 described later, the low power factor DC conversion mode is used as the low power factor discharge mode.

[0065] The control means 20 includes a preset “heating operation.” The heating operation drives the power conversion circuit 1 a while stopping or intermittently operating the cooling means 33 so that both the semiconductor switching element 110 and the freewheeling diode 111 generate heat.

[0066] During the heating operation, the cooling mechanism 33 is set to a cooling control mode of stop, intermittent operation, and constant drive. During the heating operation, the power conversion mode of the power conversion circuit 1a is set to at least one of the "AC-DC conversion mode" and the "low power factor DC-AC conversion mode".

[0067] As one example, the heating operation may be performed in the "AC-DC conversion mode" while the cooling mechanism 33 is stopped or intermittently operated. As another example, the heating operation may be performed in the "low power factor DC-AC conversion mode" while the cooling mechanism 33 is stopped or intermittently operated.

[0068] As another example, the heating operation may also be constructed such that the "first power conversion mode" is switched to the "second power conversion mode" while the cooling mechanism 33 is stopped or intermittently operated. One of the AC-DC conversion mode and the low power factor DC-AC conversion mode is set to the first power conversion mode, and the other is set to the second power conversion mode. The switching time may be when a preset time has passed after the start of the heating operation, or when the module temperature of the power conversion module 100 reaches a preset temperature after the start of the heating operation.

[0069] The control parameters when the heating operation is performed include “heating operation time” and “heating operation output power.” The heating operation time is the length of time that the heating operation is continued.

[0070] The heating operation output power is the size of the output power of the power conversion circuit 1a when the heating operation is performed. In fact, the heating operation output power can also be variably set by adjusting various control target values ​​used to control the power conversion circuit 1a. For example, if it is a charging mode, the heating operation output power can also be variably set by adjusting the size of the charging power and the charging current (active current). For example, if it is a low power factor discharge mode, the heating operation output power can also be variably set by adjusting the size of the discharge current (active current) and the reactive current.

[0071] Figure 6 1 is a diagram showing an example of a test device 200 for the power conversion device 10 according to the embodiment. The test device 200 has a system configuration of a power recirculation type.

[0072] The power recirculation type system structure is a structure in which the power supply 201, the AC power supply Vs, the power conversion device 10 as the test object, and the DC capacitor 202 are connected in a ring shape. By maintaining the output balance of the power supply 201 and the power conversion device 10, most of the power can be recirculated. As a result, the power consumption during the test can be suppressed.

[0073] exist Figure 6 2 shows the AC-DC conversion mode, i.e., the charging mode. As shown by the hollow arrows, the three-phase AC power output by the power supply 201 is transmitted to the AC end of the power conversion device 10. The power conversion device 10 generates DC power from the three-phase AC power and outputs it to the DC capacitor 202. On the other hand, in the case of the low power factor AC-DC conversion mode, i.e., the low power factor discharge mode, the power is transmitted to the AC end of the power conversion device 10. Figure 6 Cycle in the opposite direction.

[0074] Figure 7 1 is a flowchart for explaining a method for manufacturing the power conversion device 10 according to the embodiment. Figure 7 As shown, first, component preparation and assembly are performed (step S100). In this step, the power conversion module 100 is prepared with the phase change material 120 provided on the main surface 101. Furthermore, the heat dissipation surface 50a of the heat dissipation member 50 and the main surface 101 are overlapped so as to sandwich the phase change material 120.

[0075] Next, the product pre-shipment test described in steps S101 to S103 is carried out. At least step S102 in the product pre-shipment test is performed by the above-mentioned Figure 6 The test device is 200.

[0076] First, a withstand voltage test and a control voltage test are performed on the power conversion unit 1 and the power conversion device 10 (step S101 ).

[0077] Next, the main circuit is energized and the heating operation is performed (step S102). In this step, the power conversion unit 1 starts energizing the main current. The heating operation in step S102 is an operation in which the power conversion circuit 1a is driven to generate heat for both the semiconductor switch element 110 and the return diode 111 while the cooling mechanism 33 for cooling the heat dissipating component 50 is stopped or intermittently operated. For example, the heating operation mode signal S M1 When the information is input to the control unit 20, a heating operation is performed in response thereto. Thus, the phase change material 120 is heated and softened, and thus the adhesion can be improved.

[0078] Next, a steady-state performance test of the power conversion device 10 is performed (step S103). Then, the test is completed (step S104), and the product is shipped (step S105).

[0079] Figure 8 This is a flowchart for explaining the heating operation of the power conversion device 10 according to the embodiment. Figure 8 It is recorded in detail Figure 7 FIG. 1 is a diagram of the contents of step S102 in FIG. Figure 8 The routine is a process mainly executed by the mode control unit 20b2.

[0080] exist Figure 8 In the routine, first, the cooling mechanism 33 is stopped (step S1021). As a modification, instead of stopping, an intermittent operation in which the operation and the stop are switched at a certain interval may be implemented.

[0081] Next, the ambient temperature T1 of the power conversion module 100 is detected via the temperature sensor 31 (step S1022 ).

[0082] Next, calculate the heating operation time T OP (Step S1023) The specific calculation process of the heating operation time is performed using Fig. 9 This will be described later.

[0083] Next, the power conversion circuit 1a is driven in the charging mode (step S1024). Thus, the semiconductor switch element 110 and the freewheeling diode 111 are both heated while the cooling mechanism 33 for cooling the heat dissipating member 50 is stopped or intermittently operated.

[0084] The temperature of the phase change material 120 directly under the semiconductor switch element 110 when the phase change material 120 is heated by the heating operation is also referred to as the “first temperature”. The temperature of the phase change material 120 directly under the reflux diode 111 when the phase change material 120 is heated by the heating operation is also referred to as the “second temperature”.

[0085] In an embodiment, as an example, the first temperature and the second temperature are above the softening temperature of the phase change material 120, and the first temperature and the second temperature are substantially the same. For example, an error range of about 1°C to several degrees Celsius can also be regarded as substantially the same temperature. As long as the main surface 101 as a whole generates heat to the extent that the phase change material 120 is heated and softened without unevenness. Therefore, the first heat and the second heat can also be the same, but it is not limited to this, and one of the first heat and the second heat can also be greater than the other. There can also be a temperature difference of, for example, several degrees Celsius or more between the first temperature and the second temperature.

[0086] Next, it is determined whether the heating operation time set in step S1023 has passed (step S1025). Before the heating operation time has passed, the process returns to S1025, and when the heating operation time has passed, the current routine ends.

[0087] Fig. 9 Graphs for explaining the operation of the heating operation of the power conversion device 10 according to the embodiment. Specifically, Fig. 9 This is a diagram for explaining the calculation process of the heating operation time.

[0088] The control means 20 may be configured to variably set the heating operation time T1 as the time for executing the heating operation based on the ambient temperature T1 detected by the temperature sensor 31. OP The control mechanism 20 may also include a setting that increases the heating operation time T as the ambient temperature T1 increases. OP The shorter the first prescribed function or the first prescribed model is calculated.

[0089] The first predetermined function or the first predetermined model is set to have a heating operation time T corresponding to the ambient temperature T1. OP The trend of f1. Fig. 9 An example of the trend f1 is shown in FIG. The trend f1 can also be Fig. 9 As a variation example, it is also possible to replace Fig. 9 The characteristic of the heating operation time T1 can be changed by using a curve trend such as a quadratic function or a step-like function, where the ambient temperature T1 increases by a certain temperature and the heating operation time T1 increases by a certain temperature. OP The shortened trend may be in the form of a line graph in which a plurality of straight lines having different rates of change are combined.

[0090] As described above, according to the power conversion device 10 and the manufacturing method thereof of the embodiment, the heating operation is performed at a specific time of the product pre-shipment test, etc. The heating operation can form an operating state in which both the semiconductor switch element 110 and the return diode 111 are heated while suppressing the driving of the cooling mechanism 33.

[0091] This heating operation can heat and soften the phase change material 120 while suppressing temperature variations in the vicinity of the semiconductor switching element 110 and the freewheeling diode 111 on the main surface 101. As a result, variations in heating and softening of the phase change material 120 can be suppressed.

[0092] In addition, among the heating methods of the phase change material 120, there are heating by driving heat generated by the power conversion module 100 and heating by external devices such as heaters. Here, in the MPPT drive mode, etc., the power supply to the semiconductor switch element 110 is dominant, and the heat generated by the return diode 111 is usually small compared to the semiconductor switch element 110. As a result, in the MPPT drive mode, etc., there is a problem that temperature unevenness is easily formed during heating. In addition, the heating performed by external devices such as heaters has a problem of reduced production efficiency due to the increase in dedicated equipment and work workload. In this regard, according to the heating operation of the relevant embodiment, the heating and softening unevenness of the phase change material 120 can be reliably suppressed with higher production efficiency.

[0093] Modifications of the embodiment will be described below. Fig.10 and Fig.11 : is a table showing changes in the heating operation of the power conversion device 10 according to the embodiment.

[0094] exist Fig.10 and Fig.11 , the combination of heating operation mode numbers (No. 1 to No. 50), cooling control mode types, power conversion mode types, heating operation time determination methods, and heating operation output power determination methods are shown. The power conversion mode types include the number of modes and the contents of the first power conversion mode and the second power conversion mode.

[0095] For example, in the heating operation mode No. 1, the cooling mechanism 33 is stopped (OFF), the power conversion mode is only one of the charging modes, the heating operation time is calculated according to the above step S1023, and the heating operation output power is set to a preset fixed value. The other modes No. 2 to 50 can be changed from Fig.10 and Fig.11 Each table is read.

[0096] (Variable setting of heating operation output power)

[0097] In the heating operation modes No. 6 to 15, No. 21 to 30, No. 36 to 40, and No. 46 to 50, the "heating operation output power" is variably set by calculation. A modification example in which the heating operation output power is variably set will be described below.

[0098] Fig.12 This is a graph for explaining the operation of the heating operation of the power conversion device 10 according to the modification of the embodiment. Fig.13This is a flowchart for explaining the heating operation of the power conversion device 10 according to a modification of the embodiment. In this modification, the control unit 20 calculates various control target values ​​so that the heating operation output power can be variably set based on the ambient temperature T1 detected by the temperature sensor 31.

[0099] The various control target values ​​may also include at least one of an active power target value, a reactive current target value, and a target power factor. The control mechanism 20 may also include a second predetermined function or a second predetermined model set to calculate the heating operation output power to be smaller as the ambient temperature T1 is higher. For the second predetermined function or the second predetermined model, a trend f2 for determining various control target values ​​corresponding to the ambient temperature T1 is set. Fig.12 An example of the trend f2 is shown in FIG.

[0100] This modification example is implemented by Fig.13 This is achieved by referring to the flow chart. Fig.13 Yes Figure 8 The content of step S1023 is changed to the figure of step S1123. In step S1123, by referring to Fig.12 According to the trend f2 of the ambient temperature T1, various control target values ​​corresponding to the ambient temperature T1 are adjusted. As an example of step S1123, the control mechanism 20 may also increase the active current target value in the AC-DC conversion mode (charging mode) as the ambient temperature T1 is higher. In addition, as another example of step S1123, the control mechanism 20 preferably increases the reactive current target value in the low power factor DC-AC conversion mode as the ambient temperature T1 is higher, in other words, the target power factor may be lowered.

[0101] Trend f2 can also be as in Fig.12 As a variation of trend f2, a curve-like trend such as a quadratic function or higher may be used, a trend such as a step-like trend in which the heating operation output power is shortened in a step-like manner whenever the ambient temperature T1 rises by a certain temperature, or a line graph-like trend in which a plurality of straight lines with different change rates are combined may be used.

[0102] (Continuous drive of cooling mechanism and low power factor discharge mode)

[0103] Fig.10 No.3, 8, 13, 18, 23 and Fig.11 Nos. 28, 33, 38, 43, and 48 are heating operation modes in which the cooling mechanism 33 is continuously operated (always on).

[0104] Fig.14This is a flowchart for explaining the heating operation of the power conversion device 10 according to a modification of the embodiment. In this modification, the above-mentioned steps S1021 and S1024 are replaced by steps S1121 and S1124. In this modification, the cooling mechanism 33 is continuously driven in step S1121. Furthermore, in step S1124, the low power factor DC-AC conversion mode is executed in a state where the cooling mechanism 33 is continuously driven.

[0105] As a modification of the manufacturing method of the embodiment, the content of step S102 may be modified so that the cooling mechanism 33 is continuously driven. That is, in the pre-shipment test of the product, while the cooling mechanism 33 for cooling the heat sink 50 is continuously driven, the power conversion circuit 1a may be driven to generate AC power from DC power at a preset target power factor of less than 1 in a low power factor direct-to-alternating conversion mode.

[0106] (Heating stops based on module protection temperature)

[0107] Fig.11 The heating operation time of the heating operation modes No. 31 to No. 50 is not determined by calculation but is determined based on the module protection temperature. Fig.15 This is a flowchart for explaining the heating operation of the power conversion device 10 according to the modification of the embodiment.

[0108] exist Fig.15 In the modified example, the above step S1025 is replaced by step S1125. In step S1125, the control mechanism 20 performs a heating operation on the power conversion module 100 to make it reach a preset module protection temperature, and ends the heating operation once the temperature of the power conversion module 100 reaches the module protection temperature. The module protection temperature is preset as the specification of the power conversion module 100. A module temperature sensor for accurately detecting the temperature of the power conversion module 100 may be provided in addition to the temperature sensor 31.

[0109] In addition, there are Fig.10 and Fig.11 Other alternative modifications not described in the specification. For example, both the heating operation time and the heating operation time may be fixed. This is because the time and output at which the phase change material 120 is sufficiently softened can be pre-set based on calculations or the like.

[0110] In addition, you can also Fig.10 and Fig.11The selected plurality of heating operation modes may be stored in the mode control unit 20b2. Thus, for example, different heating operation variations may be used according to the product specifications of the power conversion device 10, or according to the specifications of the test device 200, test conditions, etc.

[0111] The purpose of the power conversion device 10 is not limited. The power conversion device 10 can also be provided as a power conversion device 10 for a solar power generation system, can also be provided as a power conversion device 10 for a motor drive system, and can also be provided as a power conversion device 10 for an uninterruptible power supply system. That is, it is not limited to the DC power supply 30, and various structures can be applied. The DC power supply 30 can also be a battery. The DC power supply 30 can also be a DC power supply composed of a wind turbine and a converter. The DC power supply 30 can also be a DC power supply composed of an AC power supply and a converter. It is also possible to connect a motor or a load other than the motor instead of the power system 40.

[0112] The functions of the control mechanism 20 may also be realized by a processing circuit. The processing circuit may also be dedicated hardware. The processing circuit may also include a processor and a memory. The processing circuit may also be partially formed as dedicated hardware, or may also include a processor and a memory.

[0113] When at least a part of the processing circuit is at least one dedicated hardware, the processing circuit corresponds to, for example, a single circuit, a complex circuit, a programmed processor, a parallel programmed processor, an ASIC, an FPGA, or a structure combining these.

[0114] When the processing circuit has at least one processor and at least one memory, each function of the control mechanism 20 is implemented by software, firmware, or a combination of software and firmware. Software and firmware are described as programs and stored in the memory. The program stored in the memory is read out and executed by the processor to realize the functions of each part. The processor is also called CPU (Central Processing Unit), central processing unit, processing unit, computing unit, microprocessor, microcomputer, DSP. The memory corresponds to non-volatile or volatile semiconductor memory such as RAM, ROM, flash memory, EPROM, EEPROM, etc.

[0115] In this way, the processing circuit can implement the functions of the control mechanism 20 by hardware, software, firmware or a combination thereof.

[0116] Description of symbols

[0117] 1 power conversion unit; 1a power conversion circuit; 1b gate drive substrate; 2 transformer; 3 DC side relay; 4 protection relay; 5 AC side relay; 6 reactor; 7 capacitor; 8a, 9a, 9c current transformer (CT) for measurement; 8b, 9b, 9d voltage transformer (VT) for measurement; 10 power conversion device; 20 control mechanism; 20a power conversion control unit; 20b temperature control unit; 20b1 cooling control unit; 20b2 mode control unit; 21 PWM control unit; 22 power control unit; 30 DC power supply; 31 temperature sensor; 33 cooling mechanism (cooling fan); 40 power system; 50 heat dissipation component; 50a heat dissipation surface; 100 power conversion module; 100a housing; 101 main surface (lower surface); 102 upper surface; 103 side surface; 110 semiconductor switch element; 111 return diode; 112 substrate; 114 heat sink; 116 resin sealing member; 120 phase change material; 200 test device; 201 power supply; 202 DC capacitor; S f Fan control signal; S M1 Heating operation mode signal; S PWM PWM signal; T1 temperature detection signal (ambient temperature); T OP Heating operation time.

Claims

1. A power conversion device, characterized in that: have: A power conversion module, comprising a housing having a main surface, and a semiconductor switch element and a return diode accommodated in the housing and arranged in a plane direction of the main surface, wherein the semiconductor switch element and the return diode constitute a power conversion circuit; A phase change material is disposed on the main surface of the shell; A heat dissipation component having a heat dissipation surface, wherein the heat dissipation surface is overlapped on the main surface in a manner of sandwiching the phase change material; A cooling mechanism for cooling the heat dissipation component; as well as A control mechanism that generates a drive signal for driving the power conversion circuit and controls the cooling mechanism; The control mechanism includes a pre-set heating operation; The heating operation executes a low power factor direct-to-alternating conversion mode in which the power conversion circuit is driven to generate alternating current power from direct current power at a preset target power factor of less than 1 while the cooling mechanism is stopped or intermittently operated.

2. A power conversion device, characterized in that: have: A power conversion module, comprising a housing having a main surface, and a semiconductor switch element and a return diode accommodated in the housing and arranged in a plane direction of the main surface, wherein the semiconductor switch element and the return diode constitute a power conversion circuit; A phase change material is disposed on the main surface of the shell; A heat dissipation component having a heat dissipation surface, wherein the heat dissipation surface is overlapped on the main surface in a manner of sandwiching the phase change material; A cooling mechanism for cooling the heat dissipation component; as well as A control mechanism that generates a drive signal for driving the power conversion circuit and controls the cooling mechanism; The control mechanism includes a pre-set heating operation; The heating operation is constructed such that the AC-DC conversion mode and the low power factor DC-AC conversion mode are switched from one to the other while the cooling mechanism is stopped or intermittently operated; The AC-DC conversion mode drives the power conversion circuit to generate DC power from AC power. The low power factor DC-AC conversion mode drives the power conversion circuit so as to generate AC power from DC power at a preset target power factor less than 1.

3. A method for manufacturing a power conversion device, characterized in that: include: A step of preparing a power conversion module including a housing having a main surface and a phase change material provided on the main surface, wherein the power conversion module includes a semiconductor switch element and a return diode which are accommodated in the housing and arranged in a plane direction of the main surface, and the semiconductor switch element and the return diode constitute a power conversion circuit; A step of overlapping the heat dissipation surface of the heat dissipation component and the main surface so as to sandwich the phase change material; and A step of performing a heating operation to heat the phase change material in a pre-shipment test of the product; The heating operation executes a low power factor direct-to-alternating conversion mode for driving the power conversion circuit to generate alternating current power from direct current power at a preset target power factor of less than 1 while continuously driving a cooling mechanism for cooling the heat dissipating component.

Images