Local refrigeration device and method for improving short-time pulse performance of high-power switching devices

Abstract

The present invention relates to a local refrigeration device and method for improving the short-time pulse performance of high-power switching devices, belonging to the field of flexible DC power transmission. The high-power switching device is connected to the IEGT radiator. The semiconductor refrigeration chip is arranged between the hot-end radiator and the IEGT radiator. The hot end of the semiconductor refrigeration chip is attached to the hot-end radiator, and the cold end is attached to the IEGT radiator. The first temperature sensor measures the temperature of the high-power switching device. The controller adjusts the input voltage of the semiconductor refrigeration chip according to the temperature of the high-power switching device to reduce the temperature of the high-power switching device. The semiconductor refrigeration chip is used to achieve local refrigeration and pre-refrigeration before device operation. The cold quantity generated at the cold end of the semiconductor refrigeration chip reduces the temperature of the high-power switching device, thereby reducing the device junction temperature and achieving the effect of improving the short-time pulse performance of the high-power device. The present invention does not need to increase the gate voltage and does not need to use water cooling, solves the service life problem of the DC circuit breaker, and reduces the cost.

Description

Technical Field

[0001] The present invention relates to the field of flexible DC power transmission, and particularly to a local refrigeration device and method for improving the short-time pulse performance of high-power switching devices. Background Art

[0002] In recent years, the flexible DC power transmission technology has developed rapidly, and many projects have been put into operation one after another. Especially with the successful commissioning of the Zhoushan five-terminal, Xiamen project, and Henan-Hubei flexible DC power transmission projects in China, the flexible DC power transmission technology has been pushed to a new application level. Since the damping of the DC system is relatively low, compared with the AC system, the fault development of the DC system is faster and the control and protection are more difficult. Therefore, in order to quickly limit and cut off the fault current to maintain the safe and stable operation of the DC grid and protect the key equipment in the grid, the high-voltage DC circuit breaker has become an effective and even the only technical means. The research hotspots of the high-voltage DC circuit breaker are fast breaking speed, large breaking current, and intelligent reclosing.

[0003] The core component of the DC circuit breaker, IGBT (Insulated Gate Bipolar Transistor), is a typical high-power switching device. In many projects, due to the limited current-carrying capacity of the IGBT under specific conditions, the current-carrying capacity is improved in parallel, that is, the desaturation current is increased. Combining the overall technical requirements of the Zhangbei flexible DC project for the DC circuit breaker, the transfer branch valve group needs to withstand and turn off a current of up to 25 kA for about 3 ms, and the turn-off overvoltage reaches 800 kV. However, the turn-off ability of the conventional IGBT far cannot meet the turn-off ability requirements of the transfer branch valve group for the IGBT. The current ambient temperature of the DC circuit breaker is about 50°C. Since the IGBT is affected by the ambient temperature, the increase in the ambient temperature will cause the on-state desaturation current value to decrease, reducing the short-time pulse performance. Most of the existing technologies improve the short-time pulse performance of the IGBT through the gate voltage, and this technology is very likely to reduce the life of the IGBT, thus affecting the use of the DC circuit breaker. And currently, the current cooling status of high-power switching devices such as IGBTs is mostly water cooling and natural cooling. Large-scale water cooling will lead to an increase in manufacturing costs, and natural cooling can only cool down to room temperature, and the cooling effect is not significant. Summary of the Invention

[0004] The purpose of the present invention is to provide a local refrigeration device and method for improving the short-time pulse performance of high-power switching devices, which can improve the short-time pulse performance of the DC circuit breaker by reducing the junction temperature of the high-power switching device on the basis of ensuring the service life of the DC circuit breaker.

[0005] To achieve the above purpose, the present invention provides the following solutions:

[0006] A local refrigeration device for improving the short - time pulse performance of high - power switching devices, the local refrigeration device comprising: a high - power device connection device, a semiconductor refrigeration chip, a hot - end radiator, a first temperature sensor and a controller;

[0007] The high - power switching device is connected to the IEGT radiator of the high - power device connection device;

[0008] The hot - end radiator is connected to the IEGT radiator, the semiconductor refrigeration chip is arranged between the hot - end radiator and the IEGT radiator, the hot - end of the semiconductor refrigeration chip is attached to the hot - end radiator, and the cold - end of the semiconductor refrigeration chip is attached to the IEGT radiator; the first temperature sensor is arranged on the IEGT radiator;

[0009] The signal output end of the first temperature sensor is connected to the input end of the controller, and the output end of the controller is connected to the input voltage control end of the semiconductor refrigeration chip; the controller is used to adjust the input voltage of the semiconductor refrigeration chip according to the temperature of the high - power switching device measured by the first temperature sensor, so that the temperature of the high - power switching device drops, realizing local refrigeration of the high - power switching device.

[0010] Optionally, the local refrigeration device further comprises: a second temperature sensor and a cooling fan;

[0011] The second temperature sensor is arranged on the hot - end radiator; the air flow direction of the cooling fan is parallel to the direction of the fins of the hot - end radiator;

[0012] The signal output end of the second temperature sensor is connected to the input end of the controller, and the input voltage control end of the cooling fan is connected to the output end of the controller;

[0013] The second temperature sensor is used to measure the hot - end temperature of the semiconductor refrigeration chip; the controller is used to control the input voltage of the cooling fan according to the hot - end temperature of the semiconductor refrigeration chip, adjust the air - cooled air flow of the cooling fan, and reduce the hot - end temperature of the semiconductor refrigeration chip.

[0014] Optionally, the local refrigeration device further comprises: a third temperature sensor;

[0015] The signal output end of the third temperature sensor is connected to the input end of the controller, and the third temperature sensor is used to measure the ambient temperature.

[0016] Optionally, the local refrigeration device further comprises: thermal conductive grease;

[0017] Both the hot - end and the cold - end of the semiconductor refrigeration chip are coated with thermal conductive grease.

[0018] Optionally, the local refrigeration device further comprises: an energy supply device;

[0019] The power supply device is respectively connected to the semiconductor refrigeration chip, the first temperature sensor, the second temperature sensor and the controller.

[0020] Optionally, the number of the semiconductor refrigeration chips, the hot-end radiators and the cooling fans is at least three.

[0021] Optionally, the high-power device connection device includes: two IEGT radiators and a plurality of busbars;

[0022] The high-power switching device is arranged between the two IEGT radiators; one side of each IEGT radiator is connected to at least one hot-end radiator, and the other side of each IEGT radiator is connected to a busbar.

[0023] Optionally, M3 tapped holes are formed on one side of the IEGT radiator and the hot-end radiator, M8 tapped holes are formed on the other side of the IEGT radiator, grooves are formed on the top surface of the IEGT radiator, and the bottom surface of the IEGT radiator is connected to the high-power switching device;

[0024] The M3 tapped holes of the IEGT radiator and the M3 tapped holes formed on the hot-end radiator are connected by M3 nylon screws; the IEGT radiator is connected to the busbar through the M8 tapped holes; the groove is used for placing the first temperature sensor.

[0025] A local refrigeration method for improving the short-time pulse performance of a high-power switching device, the local refrigeration method includes:

[0026] Measure the temperature of the high-power switching device at the current ambient temperature and preset the ideal temperature of the device;

[0027] When the difference between the temperature of the high-power switching device and the ideal temperature of the device is greater than the temperature threshold, gradually increase the input voltage of the semiconductor refrigeration chip until the change value of the temperature of the high-power switching device at adjacent sampling times is greater than the change threshold;

[0028] Gradually reduce the input voltage of the semiconductor refrigeration chip until the change value of the temperature of the high-power switching device at adjacent sampling times is equal to zero, record the input voltage at this time, and use the input voltage at this time as the optimal input voltage;

[0029] Control the semiconductor refrigeration chip with the optimal input voltage. When the temperature of the high-power switching device measured in real time is equal to the ideal temperature of the device or the temperature of the high-power switching device measured in real time remains unchanged within a preset time period, it is determined that the temperature of the high-power switching device has dropped to stability at the current ambient temperature, and the local refrigeration of the high-power switching device at the current ambient temperature is completed.

[0030] Optionally, when the difference between the temperature of the high-power switching device and the ideal temperature of the device is greater than the temperature threshold, gradually increase the input voltage of the thermoelectric cooler until the change value of the temperature of the high-power switching device at adjacent sampling moments is greater than the change threshold. After that, it further includes:

[0031] Control the input voltage of the cooling fan to increase to the maximum voltage.

[0032] According to the specific embodiments provided by the present invention, the following technical effects are disclosed:

[0033] The present invention discloses a local refrigeration device and method for improving the short-time pulse performance of high-power switching devices. The thermoelectric cooler is used to achieve local refrigeration and pre-cooling before device operation. The cold generated at the cold end of the thermoelectric cooler reduces the temperature of the high-power switching device, thereby reducing the device junction temperature and achieving the effect of improving the short-time pulse performance of high-power devices. The present invention does not require increasing the gate voltage and does not use water cooling, solves the life problem of DC circuit breakers, and reduces costs. Its device structure is simple and the operation reliability is improved. Description of the Drawings

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0035] Figure 1 It is a schematic diagram of the simple structure of the local refrigeration device provided by the present invention;

[0036] Figure 2 It is a schematic diagram of the detailed structure of the local refrigeration device provided by the present invention;

[0037] Figure 3 It is a schematic diagram of the structure of the high-power device connection device provided by the embodiment of the present invention;

[0038] Figure 4 It is a schematic diagram of the structure of the IEGT radiator provided by the embodiment of the present invention;

[0039] Figure 5 It is a schematic diagram of the structure of the hot-end radiator provided by the embodiment of the present invention;

[0040] Figure 6 It is a schematic diagram of the structure of the thermoelectric cooler provided by the embodiment of the present invention.

[0041] Symbolic Explanation: 1 - Hot - end radiator, 2 - IEGT radiator, 3 - Thermoelectric cooler, 4 - Bus bar, 5 - High - power switching device, 6 - Place for sensor, 7 - Flange, 8 - Epoxy pull rod, 9 - Locking nut, 10 - Pressing guide rod, 11 - Pressing seat, 12 - Disc spring gasket, 13 - M3 thread bottom hole, 14 - M8 thread bottom hole, 15 - Place for positioning pin, 16 - Groove. Detailed Implementation Manner

[0042] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0043] The purpose of the present invention is to provide a local refrigeration device and method for improving the short - time pulse performance of high - power switching devices. On the basis of ensuring the service life of the DC circuit breaker, the short - time pulse performance of the DC circuit breaker is improved by reducing the junction temperature of the high - power switching device.

[0044] To make the above - mentioned objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the drawings and specific implementation manners.

[0045] The present invention provides a local refrigeration device for improving the short - time pulse performance of high - power switching devices, as Figure 1 and 2 shown. The local refrigeration device includes: a high - power device connection device, a thermoelectric cooler 3, a hot - end radiator 1, a first temperature sensor, and a controller.

[0046] The high - power switching device 5 is connected to the IEGT radiator 2 of the high - power device connection device. The hot - end radiator 1 is connected to the IEGT radiator 2. The thermoelectric cooler 3 is disposed between the hot - end radiator 1 and the IEGT radiator 2. The hot end of the thermoelectric cooler 3 is in contact with the hot - end radiator 1, and the cold end of the thermoelectric cooler 3 is in contact with the IEGT radiator 2. The first temperature sensor is disposed on the IEGT radiator 2. The signal output end of the first temperature sensor is connected to the input end of the controller, and the output end of the controller is connected to the input voltage control end of the thermoelectric cooler 3. The controller is used to adjust the input voltage of the thermoelectric cooler 3 according to the temperature of the high - power switching device measured by the first temperature sensor, so that the temperature of the high - power switching device 5 drops, realizing local refrigeration of the high - power switching device 5.

[0047] The general idea of the present invention is to perform local refrigeration only on high-power devices without changing the ambient temperature, that is, with a constant ambient temperature. The key component of local refrigeration is the thermoelectric cooler 3. Under the influence of the ambient temperature, the cooling capacity of the thermoelectric cooler 3 is conducted to the high-power device, causing the temperature of the high-power device to decrease. With respect to the entire system, only the temperature of the high-power device and the connected part of the structure decreases, so it is called local refrigeration. As Figure 1 shown, a thermoelectric cooling device with the thermoelectric cooler 3 as the main body is added between the air and the connection device of the high-power device to achieve local refrigeration of the high-power device.

[0048] In one example, the controller is a control board with a single-chip microcomputer as the core, equipped with a peripheral sampling module and an output signal module. The structure of the thermoelectric cooler 3 is as Figure 6 shown. The side with words on the thermoelectric cooler 3 is the cold end, and the side without words is the hot end. The red connection line of the thermoelectric cooler 3 is connected to the positive pole of the power supply device, and the black connection line is connected to the negative pole of the power supply device.

[0049] The local refrigeration device further includes: a second temperature sensor and a cooling fan. The second temperature sensor is arranged on the hot-end radiator 1. The direction of the cooling fan is parallel to the direction of the fins of the hot-end radiator 1. The signal output end of the second temperature sensor is connected to the input end of the controller, and the input voltage control end of the cooling fan is connected to the output end of the controller. The second temperature sensor is used to measure the hot-end temperature of the thermoelectric cooler. The controller is used to control the input voltage of the cooling fan according to the hot-end temperature of the thermoelectric cooler, adjust the air-cooling airflow of the cooling fan, and reduce the hot-end temperature of the thermoelectric cooler 3. The cooling fan dissipates heat in the form of forced air cooling to inhibit the rapid rise of the hot-end temperature.

[0050] The local refrigeration device further includes: a third temperature sensor. The third temperature sensor is placed in the air, and the signal output end of the third temperature sensor is connected to the input end of the controller. The third temperature sensor is used to measure the ambient temperature.

[0051] The local refrigeration device further includes: thermal conductive grease. Thermal conductive grease is coated on both the hot end and the cold end of the thermoelectric cooler 3. Thermal conductive grease is selected as a substance with a relatively high thermal conductivity to ensure the effectiveness of heat conduction. Thermal conductive grease is coated on both the cold end and the hot end to ensure good heat transfer.

[0052] The local refrigeration device further includes: a power supply device. The power supply device is respectively connected to the thermoelectric cooler 3, the first temperature sensor, the second temperature sensor, and the controller. The power supply device is mainly composed of a switching power supply, and the power supply device should be a DC power supply device with adjustable and stable output voltage.

[0053] In one example, the number of thermoelectric coolers 3, hot-end radiators 1, and cooling fans is at least three. Refer to Figure 3 , the high-power device connection device includes: two IEGT radiators 2 and multiple busbars 4. The high-power switching device 5 is arranged between the two IEGT radiators 2. One side of each IEGT radiator 2 is connected to at least one hot-end radiator 1, and the other side of each IEGT radiator 2 is connected to a busbar 4. As Figure 4 shown, M3 tapped holes 13 are provided on one side of the IEGT radiator 2 and the hot-end radiator 1, M8 tapped holes 14 are provided on the other side of the IEGT radiator 2, a groove 16 is provided on the top surface of the IEGT radiator 2, and the bottom surface of the IEGT radiator 2 is connected to the high-power switching device 5. The M3 tapped holes 13 on the IEGT radiator 2 and the M3 tapped holes 13 on the hot-end radiator 1 are connected by M3 nylon screws. The IEGT radiator 2 is connected to the busbar 4 through the M8 tapped holes 14. The groove 16 is used to place the first temperature sensor. Figure 4 In

[0054] , a locating pin placement area 15 is provided at the center of the top surface of the IEGT radiator 2 for placing a locating pin. Figure 3 shown.

[0055] The present invention uses a thermoelectric cooler 3 to achieve local cooling and pre-cooling before device operation, and uses the cold generated at the cold end of the thermoelectric cooler to reduce the device temperature, thereby reducing the device junction temperature, achieving the effect of improving the short-time pulse performance of high-power devices. The present invention does not need to increase the gate voltage and does not need to use water cooling, solves the life problem of DC circuit breakers, and reduces costs. Its device structure is simple and the operation reliability is improved.

[0056] Taking the high-power device IEGT (Injection Enhanced Gate Transistor) as an example, the installation steps of the local cooling device of the present invention are as follows:

[0057] S1: Provide a semiconductor refrigeration device, a high-power device connection device, an energy supply device, a controller, and a temperature sensing module. The semiconductor refrigeration device includes a semiconductor refrigeration chip 3, a radiator, a fan, and thermal grease; the semiconductor refrigeration chip 3 includes a cold end and a hot end, and the radiator and the fan are used for dissipating heat from the hot end; the high-power device connection device is for connecting the high-power switching device 5. The energy supply device is used for the operation of the semiconductor refrigeration device, the controller, and the temperature sensing module, and is mainly composed of a switching power supply; the controller is mainly composed of a control board, and its main function is to receive input signals and control output signals. The temperature sensing module is mainly composed of a temperature sensor.

[0058] S2: The high-power device connection device adopts a traditional crimping device and is connected in the Figure 3 way, where the M3 threaded hole of the IEGT radiator 2 and the M3 hole of the hot-end radiator 1 are connected with an M3 nylon screw, the semiconductor refrigeration chip 3 is sandwiched between the IEGT radiator 2 and its hot-end radiator 1, its hot end is in contact with the hot-end radiator 1, the cold end is in contact with the IEGT radiator 2 to generate cold, and both the cold end and the hot end are coated with thermal grease to ensure good heat transfer. The structure of its hot-end radiator 1 is as shown in Figure 5 . The M8 threaded hole of the IEGT is connected to the busbar 4, and the structural diagram after connection is as shown in Figure 2 .

[0059] S3: Install a cooling fan. The semiconductor hot-end radiator 1 mainly dissipates heat from the hot end in the form of air cooling by the cooling fan, and the direction of the cooling fan is parallel to the direction of the fins of the hot-end radiator 1.

[0060] S4: Install a temperature sensor. Install the temperature sensor into the groove 16 of the IEGT radiator 2, and the position is as shown in Figure 4 . Another sensor placed on the surface of the hot-end radiator 1 is placed at the sensor placement location 6, and the position is as shown in Figure 2 . There is also one placed in the air, and all three temperature sensors are connected to the sampling module of the controller.

[0061] S5: Connect the energy supply device. Connect the power supply lines of the semiconductor refrigeration chip 3, the cooling fan, the temperature sensor, and the controller to each switching power supply to maintain power supply and ensure the normal operation of the device.

[0062] S6: Turn on the energy supply device, and all devices work normally.

[0063] The present invention also provides a local refrigeration method for improving the short-time pulse performance of a high-power switching device. The local refrigeration method includes:

[0064] Step 1, measure the temperature of the high-power switching device at the current ambient temperature and preset the ideal temperature of the device.

[0065] Step 2: When the difference between the temperature of the high-power switching device and the ideal temperature of the device is greater than the temperature threshold, gradually increase the input voltage of the thermoelectric cooler 3 until the change value of the temperature of the high-power switching device at adjacent sampling moments is greater than the change threshold.

[0066] After Step 2, to prevent the temperature at the hot end from rising due to the increase in the input voltage of the thermoelectric cooler 3, resulting in insufficient cooling capacity at the cold end, the controller controls the input voltage of the cooling fan to increase to the maximum voltage.

[0067] Step 3: Gradually reduce the input voltage of the thermoelectric cooler 3 until the change value of the temperature of the high-power switching device at adjacent sampling moments is equal to zero, record the input voltage at this time, and use the input voltage at this time as the optimal input voltage.

[0068] Step 4: Control the thermoelectric cooler 3 with the optimal input voltage. When the temperature of the high-power switching device measured in real time is equal to the ideal temperature of the device or the temperature of the high-power switching device measured in real time remains unchanged within a preset time period, it is determined that the temperature of the high-power switching device 5 has dropped to stability under the current ambient temperature, and the local cooling of the high-power switching device 5 under the current ambient temperature is completed.

[0069] The principle of the local cooling method of the present invention is as follows:

[0070] Use the temperature sensing module to measure the air temperature T1, the temperature of the high-power device T2, and the temperature of the hot end of the thermoelectric cooler T3, ensure that T1, T2, and T3 are close, and transmit the output signal of the sensor to the controller for processing based on T1, T2, and T3. Turn on the energy supply device to make the thermoelectric cooling device operate normally. After starting the cooling, process these temperature quantities T1, T2, and T3. The thermoelectric cooler 3 is composed of P-type and N-type semiconductor materials. The heat absorbed from the cold end, the heat conducted from the hot end, and the Joule heat generated by the current will eventually reach a thermal equilibrium, and the thermal equilibrium equation can be obtained: Q c = αIT2 + K(T2 - T3) - 0.5I 2 R. According to Ohm's law U = IR, the input voltage U of the thermoelectric cooler 3 can be adjusted TEC to adjust Q c and thus adjust the temperature T2. In the formula: Q c is the heat absorbed by the cold end of the thermoelectric cooler, unit: W; α is the Seebeck coefficient of the semiconductor device, unit: V / W; K is the total thermal conductivity of the semiconductor device, unit: W / K; I is the loop current, unit: A; R is the internal resistance of the semiconductor device, unit: Ω.

[0071] The controller receives the temperature signal output by the temperature sensing module, mainly to control the temperature T2 of the IEGT device. The main steps are as follows:

[0072] S7.1: Set an ideal final device temperature T4, and measure the air temperature T1, the IEGT device temperature T2, and the hot end temperature T3 of the thermoelectric cooler.

[0073] S7.2: When T2 - T4 is greater than a certain threshold, it means that the temperature difference between the cold end and the preset temperature is too large at this time. Therefore, the thermoelectric cooling device needs more cooling capacity, that is, Q c should be greater than the threshold. From this, the temperature condition is calculated. At this time, the input voltage U TEC of the thermoelectric cooler 3 should be increased, and at this time, the voltage U FAN of the fan of the semiconductor hot end radiator 1 is also increased, so that the hot end temperature T3 will not rise due to the increase of U TEC , resulting in insufficient cooling capacity at the cold end. The process of increasing U TEC and U FAN is realized by the controller.

[0074] S7.3: According to the heat balance equation, Q c =αIT2 + K(T2 - T3)-0.5I 2 R, it can be seen that during the process of increasing U TEC , due to the existence of the Joule heat of the thermoelectric cooler 3 itself, if U TEC is continuously increased, the heat absorbed at the cold end will decrease, and the cold end temperature will rise. Therefore, within a certain range, there is an optimal U TEC value, so that Q c reaches a maximum value. Therefore, when the semiconductor input voltage U TEC gradually increases, ΔT2 less than 0 means that the thermoelectric cooling device is still cooling and has not reached the optimal U TEC . Until ΔT2 is greater than 0, record the current U TEC at each time interval, and when ΔT2 is greater than a certain threshold, stop increasing the voltage and drop the voltage back to the voltage U TEC when ΔT2 is equal to 0. The U TEC at that moment is the optimal value.

[0075] S7.4: Continue to operate under the optimal U TEC . When T2 = T4 or T2 remains unchanged for a period of time, the local cooling of the high-power device at the ambient temperature T1 is completed, and it is considered that at the ambient temperature T1, the temperature T2 of the high-power device drops to a stable state.

[0076] The present invention can also use a heating device to change the ambient temperature T1, increase the number of thermoelectric cooling chips 3, and repeat the operation of the local refrigeration method, so as to achieve local refrigeration of high-power devices at different ambient temperatures T1.

[0077] Compared with the prior art, on the basis of ensuring the service life of the DC circuit breaker with the gate voltage being the same as that in the existing project, the present invention improves the short-time pulse performance of high-power devices by reducing the junction temperature of the high-power devices, without the need to use water cooling, and is convenient to implement with low cost.

[0078] In this specification, the various embodiments are described in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts among the various embodiments can be referred to each other.

[0079] In this article, specific examples are used to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A local refrigeration device for improving the short-time pulse performance of a high-power switching device, characterized in that, The local refrigeration device includes: a high-power device connection device, a semiconductor refrigeration chip, a hot-end radiator, a first temperature sensor, and a controller; The high-power switching device is connected to the IEGT radiator of the high-power device connection device; The hot-end radiator is connected to the IEGT radiator. The semiconductor refrigeration chip is arranged between the hot-end radiator and the IEGT radiator. The hot end of the semiconductor refrigeration chip is attached to the hot-end radiator, and the cold end of the semiconductor refrigeration chip is attached to the IEGT radiator. The first temperature sensor is arranged on the IEGT radiator. The number of the semiconductor refrigeration chips, the hot-end radiators, and the cooling fans is at least three. The high-power device connection device includes: two IEGT radiators and multiple busbars. The high-power switching device is arranged between the two IEGT radiators. One side of each IEGT radiator is connected to at least one hot-end radiator, and the other side of each IEGT radiator is connected to a busbar; The signal output end of the first temperature sensor is connected to the input end of the controller, and the output end of the controller is connected to the input voltage control end of the semiconductor refrigeration chip. The controller is used to adjust the input voltage of the semiconductor refrigeration chip according to the temperature of the high-power switching device measured by the first temperature sensor, so as to reduce the temperature of the high-power switching device and realize the local refrigeration of the high-power switching device; The local refrigeration device further includes: a second temperature sensor and a cooling fan; The second temperature sensor is arranged on the hot-end radiator. The wind direction of the cooling fan is parallel to the direction of the fins of the hot-end radiator; The signal output end of the second temperature sensor is connected to the input end of the controller, and the input voltage control end of the cooling fan is connected to the output end of the controller; The second temperature sensor is used to measure the hot-end temperature of the semiconductor refrigeration chip. The controller is used to control the input voltage of the cooling fan according to the hot-end temperature of the semiconductor refrigeration chip, adjust the air-cooling air flow of the cooling fan, and reduce the hot-end temperature of the semiconductor refrigeration chip; The process of realizing the local refrigeration of the high-power switching device includes: Measuring the temperature of the high-power switching device at the current ambient temperature and presetting the ideal temperature of the device; When the difference between the temperature of the high-power switching device and the ideal temperature of the device is greater than the temperature threshold, gradually increase the input voltage of the semiconductor refrigeration chip until the change value of the temperature of the high-power switching device at adjacent sampling moments is greater than the change threshold; Gradually reduce the input voltage of the semiconductor refrigeration chip until the change value of the temperature of the high-power switching device at adjacent sampling moments is equal to zero, record the input voltage at this time, and use the input voltage at this time as the optimal input voltage; Controlling the semiconductor refrigeration chip with the optimal input voltage. When the temperature of the high-power switching device measured in real time is equal to the ideal temperature of the device or the temperature of the high-power switching device measured in real time remains unchanged within a preset time period, it is determined that the temperature of the high-power switching device has dropped to stability at the current ambient temperature, and the local refrigeration of the high-power switching device at the current ambient temperature is completed.

2. The local refrigeration device for improving the short-time pulse performance of the high-power switching device according to claim 1, characterized in that, The local refrigeration device further includes: a third temperature sensor; The signal output end of the third temperature sensor is connected to the input end of the controller, and the third temperature sensor is used to measure the ambient temperature.

3. The local refrigeration device for improving the short-time pulse performance of the high-power switching device according to claim 1, characterized in that The local refrigeration device further includes: thermal conductive silicone grease; The hot end and the cold end of the semiconductor refrigeration chip are both coated with thermal conductive silicone grease.

4. The local refrigeration device for improving the short-time pulse performance of the high-power switching device according to claim 1, wherein The local refrigeration device further includes: an energy supply device; The energy supply device is respectively connected to the semiconductor refrigeration chip, the first temperature sensor, the second temperature sensor and the controller.

5. The local refrigeration device for improving the short-time pulse performance of the high-power switching device according to claim 1, characterized in that, M3 threaded bottom holes are opened on one side surface of the IEGT radiator and the hot end radiator, an M8 threaded bottom hole is opened on the other side surface of the IEGT radiator, a groove is opened on the top surface of the IEGT radiator, and the bottom surface of the IEGT radiator is connected to the high-power switching device; The M3 threaded bottom hole of the IEGT radiator and the M3 threaded bottom hole opened on the hot end radiator are connected by an M3 nylon screw; the IEGT radiator is connected to the bus bar through the M8 threaded bottom hole; the groove is used to place the first temperature sensor.

6. A local refrigeration method for improving the short-time pulse performance of high-power switching devices, characterized in that, The local refrigeration method is applied to the local refrigeration device according to any one of claims 1-5, and the local refrigeration method includes: Measuring the temperature of the high-power switching device at the current ambient temperature and presetting the ideal temperature of the device; When the difference between the temperature of the high-power switching device and the ideal temperature of the device is greater than the temperature threshold, gradually increase the input voltage of the semiconductor refrigeration chip until the change value of the temperature of the high-power switching device at adjacent sampling times is greater than the change threshold; Gradually reduce the input voltage of the semiconductor refrigeration chip until the change value of the temperature of the high-power switching device at adjacent sampling times is equal to zero, record the input voltage at this time, and use the input voltage at this time as the optimal input voltage; Controlling the semiconductor refrigeration chip with the optimal input voltage, when the temperature of the high-power switching device measured in real time is equal to the ideal temperature of the device or the temperature of the high-power switching device measured in real time remains unchanged within a preset time period, it is determined that the temperature of the high-power switching device has dropped to stability at the current ambient temperature, and the local refrigeration of the high-power switching device at the current ambient temperature is completed.

7. The local refrigeration method for improving the short-time pulse performance of a high-power switching device according to claim 6, characterized in that, After the step of when the difference between the temperature of the high-power switching device and the ideal temperature of the device is greater than the temperature threshold, gradually increasing the input voltage of the semiconductor refrigeration chip until the change value of the temperature of the high-power switching device at adjacent sampling times is greater than the change threshold, it further includes: Controlling the input voltage of the cooling fan to increase to the maximum voltage.

Images