Motor controller and electric driving system
By setting a temperature control circuit in the motor controller, the case temperature of the power semiconductor devices in the hybrid switch is collected and judged, and the high-temperature devices are disconnected, thus solving the problem of low efficiency caused by heat conduction and realizing the improvement of device efficiency and system performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ZHEJIANG GEELY HLDG GRP CO LTD
- Filing Date
- 2025-05-19
- Publication Date
- 2026-04-24
AI Technical Summary
Different types of power semiconductor devices have lower efficiency due to heat conduction during motor driving, and high-temperature devices affect the efficiency of low-temperature devices.
A temperature control circuit is set in the motor controller. The case temperature of each power semiconductor device in the hybrid switch is collected by a temperature sensor. A comparator and a subtractor are used to determine the device with the highest case temperature. The control unit disconnects the high-temperature device based on the processing result.
It reduces heat conduction between power semiconductor devices, improves device efficiency, protects low-temperature devices, and enhances system performance.
Smart Images
Figure CN224164793U_ABST
Abstract
Description
Technical Field
[0001] This application relates to motor technology, and more particularly to a motor controller and an electric drive system. Background Technology
[0002] During motor driving, a power module composed of power semiconductor devices can be used to invert DC power into AC power for motor use.
[0003] Currently, hybrid switches composed of various types of power semiconductor devices are used as power modules to improve their efficiency. However, different types of power semiconductor devices have different maximum operating temperatures. During use, due to heat conduction, power semiconductor devices with higher operating temperatures can affect those with lower operating temperatures, resulting in lower efficiency for the latter. Utility Model Content
[0004] This application provides a motor controller and an electric drive system to solve the problem of low efficiency in power semiconductor devices.
[0005] In a first aspect, this application provides a motor controller, including: a control unit, a plurality of hybrid switches, and a temperature control circuit corresponding to each hybrid switch, wherein each hybrid switch includes a first power semiconductor device and a second power semiconductor device connected in parallel; the first power semiconductor device and the second power semiconductor device are of different types; the hybrid switch is connected to the control unit, and the temperature control circuit is connected to the control unit;
[0006] The temperature control circuit is used to process the case temperature of each power semiconductor device in the hybrid switch corresponding to the temperature control circuit and output the processing result; wherein, the processing result represents the power semiconductor device with the highest current case temperature.
[0007] The control unit is used to control the power semiconductor device with the highest current case temperature to disconnect based on the received processing result.
[0008] In some possible implementations, the temperature control circuit includes a comparator, a temperature sensor corresponding to a first power semiconductor device, and a temperature sensor corresponding to a second power semiconductor device; the input terminal of the comparator is connected to the temperature sensor, and the output terminal of the comparator is connected to the control unit.
[0009] In some possible implementations, the temperature sensor corresponding to the first power semiconductor device is connected to the positive terminal of the comparator's input, and the temperature sensor corresponding to the second power semiconductor device is connected to the negative terminal of the comparator's input.
[0010] The comparator is configured to output a high-level signal when the case temperature of the first power semiconductor device is greater than that of the second power semiconductor device, and to output a low-level signal when the case temperature of the first power semiconductor device is less than that of the second power semiconductor device.
[0011] In some possible implementations, the temperature control circuit further includes a subtractor, the input of which is connected to the temperature sensor, and the output of which is connected to the input of the comparator.
[0012] The subtractor is used to determine the difference between the case temperature of the first power semiconductor device and the case temperature of the second power semiconductor device.
[0013] In some possible implementations, the temperature sensor corresponding to the first power semiconductor device is connected to the positive terminal of the input of the subtractor, and the temperature sensor corresponding to the second power semiconductor device is connected to the negative terminal of the input of the subtractor; the positive terminal of the input of the comparator is connected to the output of the subtractor, and the negative terminal of the input of the comparator is a preset positive threshold and a preset negative threshold.
[0014] The comparator is configured to output a high-level signal when the difference is greater than the positive threshold, and to output a low-level signal when the difference is less than the negative threshold.
[0015] In some possible implementations, the comparator output includes a high-level signal and a low-level signal, the temperature control circuit further includes a counter, the output of the comparator is connected to the counter, and the counter is connected to the control unit;
[0016] The counter is used to increment by one when the high-level signal is received, decrement by one when the low-level signal is received, and output the count value.
[0017] In some possible implementations, the control unit is specifically configured to receive the count value output by the counter, control the first power semiconductor device to disconnect when the count value is greater than a first value, and control the second power semiconductor device to disconnect when the count value is less than a second value.
[0018] In some possible implementations, the first power semiconductor device is a silicon device, and the second power semiconductor device is a silicon carbide device or a gallium nitride device.
[0019] In some possible implementations, the motor controller further includes a driver chip; the driver chip is connected to the control unit and the hybrid switch, respectively.
[0020] Secondly, this application provides an electric drive system, including a power supply, a motor, and a motor controller as described in any one of the first aspects, wherein the motor controller is connected to the motor and the power supply respectively.
[0021] The motor controller and electric drive system provided in this application acquire the case temperature of each power semiconductor device in the hybrid switch by setting a corresponding temperature control circuit for each hybrid switch in the motor controller, and perform judgment processing to obtain a processing result that can characterize the power semiconductor device with the highest current case temperature. Based on this processing result, the control unit can control the disconnection of the power semiconductor device with the highest current case temperature. In this way, the motor controller can achieve case temperature control of each power semiconductor device based on the temperature control circuit, reducing heat conduction between power semiconductor devices in the hybrid switch, thereby reducing the impact of high-temperature devices on low-temperature devices and improving the efficiency of the power semiconductor devices. Attached Figure Description
[0022] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.
[0023] Figure 1 A schematic diagram illustrating one application scenario provided in this application;
[0024] Figure 2 This application provides a schematic diagram of the structure of a hybrid power module;
[0025] Figure 3 This application provides a schematic diagram of the structure of a driver chip;
[0026] Figure 4 A schematic diagram of the structure of a motor controller provided in this application;
[0027] Figure 5 A schematic diagram of a temperature control circuit provided in this application;
[0028] Figure 6 A schematic diagram of another temperature control circuit provided in this application;
[0029] Figure 7 A schematic diagram of another temperature control circuit provided in this application;
[0030] Figure 8 A schematic diagram of another temperature control circuit provided in this application;
[0031] Figure 9 This is a schematic diagram of the structure of an electric drive system provided in this application.
[0032] Explanation of reference numerals in the attached figures:
[0033] 100: Motor controller;
[0034] 101: Control unit;
[0035] 102: Hybrid power module;
[0036] 103: Driver chip;
[0037] 201: Temperature control circuit;
[0038] 202: Comparator;
[0039] 203: Temperature sensor corresponding to the first power semiconductor device;
[0040] 204: Temperature sensor corresponding to the second power semiconductor device;
[0041] 205: Subtractor;
[0042] 206: Counter;
[0043] 300: Electric drive system;
[0044] 301: Power supply;
[0045] 302: Electric motor;
[0046] 1021: Hybrid switch;
[0047] 1022: First power semiconductor device;
[0048] 1023: Second power semiconductor device;
[0049] 1031: Driver module;
[0050] 1032: Driver chip for the first power semiconductor device;
[0051] 1033: Driver chip for second power semiconductor devices.
[0052] The accompanying drawings have illustrated specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to specific embodiments. Detailed Implementation
[0053] To make the objectives, technical solutions, and advantages of this utility model clearer, the embodiments of this utility model will be described in further detail below with reference to the accompanying drawings.
[0054] It should be understood that the described embodiments are merely some embodiments of this utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.
[0055] In the following description, when referring to the accompanying drawings, the same numbers in different drawings denote the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this invention. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this invention as detailed in the appended claims.
[0056] In the description of this utility model, it should be understood that the terms "first," "second," "third," etc., are only used to distinguish similar objects and are not necessarily used to describe a specific order or sequence, nor should they be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances. Furthermore, in the description of this utility model, unless otherwise stated, "multiple" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.
[0057] First, the terms used in this application will be explained:
[0058] Case temperature: The case temperature is measured through a small hole in the bottom of the power semiconductor device that penetrates the heat sink and the thermal interface material.
[0059] Silicon devices: These are power semiconductor devices whose main semiconductor material is silicon, such as insulated gate bipolar transistors (IGBTs).
[0060] Silicon carbide (SiC) devices: These are power semiconductor devices whose main semiconductor material is SiC. For example, they can be SiC-metal-oxide-semiconductor field-effect transistors (SiC-MOSFETs).
[0061] Gallium nitride (GaN) devices: These are power semiconductor devices whose primary semiconductor material is GaN, such as GaN-MOSFETs. It should be noted that in this application, SiC represents silicon carbide devices, and GaN represents gallium nitride devices.
[0062] Figure 1 This is a schematic diagram illustrating one application scenario provided by this application. For example... Figure 1 As shown, the motor controller 100 includes a control unit 101 and a hybrid power module 102, wherein the hybrid power module includes multiple hybrid switches 1021, and the control unit 101 is connected to the hybrid power module 102. It should be noted that... Figure 1 The following is an example illustrating the use of two hybrid switches.
[0063] Optionally, the motor controller 100 may also include a drive chip 103, which is connected to the control unit 101 and the hybrid power module 102 respectively. In other words, the drive chip 103 is connected to the control unit 101 and the hybrid switch 1021 respectively.
[0064] The aforementioned control unit 101 is used to monitor, adjust, and control the operating state of the motor, and output control signals and control strategies to the drive chip. The control signal may be, for example, a pulse width modulation (PWM) signal. This control unit may be a microcontroller unit (MCU) or a central processing unit (CPU), or other chip with processing capabilities; this embodiment of the application is not limited to these specific cases.
[0065] The aforementioned hybrid power module 102 is used to convert DC power into three-phase AC power with adjustable frequency and voltage, providing a suitable drive power for the three-phase motor so that the motor can operate at the desired speed and torque. It is understood that the motor winding current includes three phases: U, V, and W. (Refer to...) Figure 2 As shown, Figure 2 This is a schematic diagram of the structure of a hybrid power module provided in this application. The hybrid power module 102 is a three-phase full-bridge module. Each bridge arm is equipped with a hybrid switch 1021. The hybrid power module 102 is connected to the U, V, and W three-phase windings of the motor 302 and outputs U, V, and W three-phase currents to the motor.
[0066] Continue to refer to Figure 2As shown, the hybrid power module 102 includes multiple hybrid switches 1021. Each hybrid switch includes a first power semiconductor device 1022 and a second power semiconductor device 1023 connected in parallel. The first power semiconductor device 1022 and the second power semiconductor device 1023 are of different types. The first power semiconductor device 1022 can be a silicon device, such as an IGBT; the second power semiconductor device 1023 can be a silicon carbide device or a gallium nitride device, such as a SiC-MOSFET or a GaN-MOSFET. In other words, the hybrid switch can be a hybrid switch composed of IGBTs and SiC-MOSFETs connected in parallel, or a hybrid switch composed of IGBTs and GaN-MOSFETs connected in parallel, or other hybrid switch forms, which can be set according to actual needs. It should be noted that this application does not limit the number of first power semiconductor devices and second power semiconductor devices included in each hybrid switch. For example, the hybrid switch can be two SiC-MOSFETs connected in series and then in parallel with one IGBT, or one IGBT and one SiC-MOSFET connected in parallel. Figure 2 This example illustrates the concept of a system with six hybrid switches. It should be noted that... Figure 2 SiC is used to characterize silicon carbide devices, and GaN is used to characterize gallium nitride devices.
[0067] The aforementioned driver chip 103 is used to output a gate drive signal according to the control signal and control strategy from the control unit, so as to control the turn-on and turn-off of the power semiconductor devices in the hybrid power module. Figure 3 This application provides a schematic diagram of the structure of a driver chip, such as... Figure 3 As shown, the driver chip 103 may include multiple driver modules 1031. Each driver module 1031 includes a driver chip 1032 for a first power semiconductor device and a driver chip 1033 for a second power semiconductor device, which are used to control the on / off state of the first power semiconductor device 1022 and the second power semiconductor device 1023, respectively. It should be noted that the driver chip for the first power semiconductor device and the driver chip for the second power semiconductor device are respectively configured in a one-to-one correspondence with the first power semiconductor device and the second power semiconductor device.
[0068] The motor controller 100 can send control signals and control strategies to the drive chip 103 based on the control unit 101, so that the drive chip generates gate drive signals based on the control signals and control strategies to control the on / off of the first power semiconductor device and the second power semiconductor device in each hybrid switch in the hybrid power module 102. In this way, the input DC power can be simulated to have the waveform characteristics of AC power, realizing the inversion process from DC to AC power, and obtaining AC power that meets the motor operation requirements.
[0069] refer to Figure 2 As shown, the first and second power semiconductor devices in the hybrid switch are of different types and have different maximum operating temperatures. For example, the maximum operating temperature of an IGBT is 175℃, while that of a SiC-MOSFET is greater than or equal to 195℃. The device with the higher case temperature is called the high-temperature device, and the corresponding device is called the low-temperature device. Therefore, during operation, as the case temperature rises, the high-temperature device, through heat conduction, will affect the operation of the low-temperature device. For example, due to the temperature difference between the high-temperature and low-temperature devices, the temperature of the low-temperature device rises due to heat conduction, increasing its losses and reducing its efficiency, resulting in lower efficiency for the hybrid switch.
[0070] Therefore, it is necessary to control the case temperature of power semiconductor devices. This application sets up a temperature control circuit for each hybrid switch, and determines the high-temperature device in the power semiconductor device by judging the case temperature of each semiconductor power device in the collected hybrid switch, so as to control the high-temperature device to disconnect, reduce the influence of the high-temperature device on the low-temperature device, and improve the efficiency of the power semiconductor device.
[0071] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will be described below with reference to the accompanying drawings.
[0072] Figure 4 This is a schematic diagram of the structure of a motor controller provided in this application. Figure 4 As shown, in Figure 1 Based on the motor controller shown, a corresponding temperature control circuit 201 is set for each hybrid switch, and the temperature control circuit 201 is connected to the control unit 101. It should be noted that... Figure 4 The following is an example illustrating the use of two hybrid switches and two temperature control circuits.
[0073] The temperature control circuit 201 processes the case temperatures of each power semiconductor device in the hybrid switch corresponding to the temperature control circuit, and outputs a processing result; wherein the processing result represents the power semiconductor device with the highest current case temperature, i.e., the high-temperature device. For example, the temperature control circuit may include a temperature sensor, and the processing is based on the case temperatures of each power semiconductor device collected by the temperature sensor to obtain a processing result that represents the power semiconductor device with the highest current case temperature. For example, a comparator can be used to compare the case temperatures of each power semiconductor device to obtain the processing result.
[0074] The control unit 101 is used to control the power semiconductor device with the highest current case temperature to disconnect based on the received processing result. For example, after receiving the processing result, if the control unit determines that the processing result indicates that the case temperature of the first power semiconductor device is greater than that of the second power semiconductor device, it can send a control signal to the driver chip 103 to control the disconnection of the first power semiconductor device.
[0075] In this embodiment, a corresponding temperature control circuit is set up in the motor controller for each hybrid switch to collect the case temperature of each power semiconductor device in the hybrid switch, and perform judgment processing to obtain a processing result that can characterize the power semiconductor device with the highest current case temperature. Based on this processing result, the control unit can control the power semiconductor device with the highest current case temperature to disconnect. In this way, the motor controller can achieve case temperature control of each power semiconductor device based on the temperature control circuit, reducing heat conduction between power semiconductor devices in the hybrid switch, thereby reducing the impact of high-temperature devices on low-temperature devices and improving the efficiency of the power semiconductor devices.
[0076] In some embodiments, Figure 5 This is a schematic diagram of a temperature control circuit provided in this application. Figure 5 As shown, the temperature control circuit 201 includes a comparator 202, a temperature sensor 203 corresponding to a first power semiconductor device, and a temperature sensor 204 corresponding to a second power semiconductor device. The input terminal of the comparator 202 is connected to the temperature sensor, and the output terminal of the comparator 202 is connected to the control unit 101. The temperature sensor 203 corresponding to the first power semiconductor device and the temperature sensor 204 corresponding to the second power semiconductor device are disposed inside the hybrid switch 1021. This embodiment does not limit the location or method of the temperature sensors.
[0077] For example, the temperature sensor 203 corresponding to the first power semiconductor device can be used to collect the case temperature of the first power semiconductor device, and the temperature sensor 204 corresponding to the second power semiconductor device can be used to collect the case temperature of the second power semiconductor device. The comparator 202 can determine the processing result by comparing the case temperature of the first power semiconductor device with the case temperature of the second power semiconductor device.
[0078] For details, please refer to Figure 5 As shown, the temperature sensor 203 corresponding to the first power semiconductor device and the positive terminal of the input terminal of the comparator 202 ( Figure 5 The temperature sensor 204 corresponding to the second power semiconductor device is connected to the negative terminal of the input terminal of the comparator 202 via a "+" connection. Figure 5 Connect with "-" in the middle.
[0079] Comparator 202 can be used to output a high-level signal when the case temperature of the first power semiconductor device is greater than that of the second power semiconductor device, and to output a low-level signal when the case temperature of the first power semiconductor device is less than that of the second power semiconductor device. Optionally, if the case temperature of the first power semiconductor device is equal to that of the second power semiconductor device, a preset signal can be output. The form of the preset signal is not limited in this embodiment.
[0080] It should be noted that this application does not limit the connection method between the temperature sensor corresponding to the power semiconductor device and the positive and negative input terminals of the comparator.
[0081] Similarly, when the hybrid switch 1021 includes two or more power semiconductor devices, the comparator can also output the processing result. It is understandable that, taking an example including one first power semiconductor device and two second power semiconductor devices, the two second power semiconductor devices are connected in series and then in parallel with the first power semiconductor device. Therefore, although the comparator needs to compare the case temperatures of the three power semiconductor devices, since the two second power semiconductor devices are connected in series, they will be switched on and off simultaneously. The output level signal can be determined by identifying which type of power semiconductor device has the highest case temperature. That is, a high-level signal can be output when the case temperature of the first power semiconductor device is higher than that of the second power semiconductor device, and a low-level signal can be output when the case temperature of the first power semiconductor device is lower than that of the second power semiconductor device.
[0082] In some possible implementations, Figure 6 A schematic diagram of another temperature control circuit provided in this application. Figure 6 As shown, the temperature control circuit 201 also includes a counter 206. The output of the comparator 202 is connected to the counter 206, and the counter 206 is connected to the control unit 101.
[0083] Counter 206 increments by one when a high-level signal is received and decrements by one when a low-level signal is received, then outputs the count value. For example, the counter can count the received level signals within each PWM signal cycle, incrementing by one when a high-level signal is received and decrementing by one when a low-level signal is received, then outputting the count value. In this implementation, the count value represents the number of times within one cycle that the case temperature of the first power semiconductor device is greater than the case temperature of the second power semiconductor device, or vice versa.
[0084] Optionally, the counter value is reset to zero after each PWM signal cycle. This method allows for monitoring of the level signal within a cycle using a simple hardware structure.
[0085] In some possible implementations, the control unit 101 can use software to statistically analyze the level signal within a cycle and output a count value. This eliminates the need for a separate counter, reducing hardware costs.
[0086] Furthermore, the control unit 101 is specifically used to receive the count value output by the counter 206. When the count value is greater than a first value, it indicates that the case temperature of the first power semiconductor device has always been greater than that of the second power semiconductor device during this cycle, meaning the high-temperature device is the first power semiconductor device, and thus the first power semiconductor device is controlled to disconnect. When the count value is less than a second value, it indicates that the case temperature of the first power semiconductor device has always been less than that of the second power semiconductor device during this cycle, meaning the high-temperature device is the second power semiconductor device, and thus the second power semiconductor device is controlled to disconnect. In this way, the count value output by the counter can be adjusted in real time according to the comparator output during each control cycle of the PWM signal, and the switching state of the power semiconductor devices can be precisely controlled according to the count value, achieving more precise temperature control. In each cycle, heat conduction between power semiconductor devices in the mixed switching can be reduced, thereby reducing the impact of the high-temperature device on the low-temperature device, improving the efficiency of the power semiconductor devices, and thus more effectively protecting the power devices and improving system performance.
[0087] In this embodiment, a temperature control circuit equipped with a comparator, a temperature sensor corresponding to the first power semiconductor device, and a temperature sensor corresponding to the second power semiconductor device can collect the case temperatures of the first and second power semiconductor devices in the hybrid switch based on the temperature sensors. The comparator then compares and processes the collected case temperatures, outputting a processing result representing the power semiconductor device with the highest current case temperature. The control unit can then disconnect the power semiconductor device with the highest current case temperature based on this processing result. This method, using a comparator to compare and process the collected case temperatures, can accurately determine the differences in case temperatures. The hardware structure is relatively simple, requiring no complex software programs, thus reducing the design difficulty and cost of the system. Furthermore, using a comparator to monitor the case temperature offers higher real-time performance compared to software control and avoids interference from software vulnerabilities, resulting in higher reliability and accuracy.
[0088] In some embodiments, Figure 7 A schematic diagram of another temperature control circuit provided in this application. Figure 7 As shown, the temperature control circuit 201 also includes a subtractor 205. The input terminal of the subtractor 205 is connected to the temperature sensor, and the output terminal of the subtractor 205 is connected to the input terminal of the comparator 202.
[0089] Subtractor 205 is used to determine the difference between the case temperature of the first power semiconductor device and the case temperature of the second power semiconductor device.
[0090] Furthermore, comparator 202 can be used to compare the difference with a preset threshold and output the processing result.
[0091] For details, please refer to Figure 7 As shown, the temperature sensor 203 corresponding to the first power semiconductor device is the positive terminal of the input terminal of the subtractor 205. Figure 7 The "+" connection in the middle, the temperature sensor 204 corresponding to the second power semiconductor device and the negative terminal of the input terminal of the subtractor 205 ( Figure 7 The input of comparator 202 is connected by a "-" symbol; the positive input of comparator 202 is connected to the output of subtractor 205, and the negative input of comparator 202 is a preset positive threshold and a preset negative threshold. These preset positive and negative thresholds characterize the difference between the case temperature of the first power semiconductor device and the case temperature of the second power semiconductor device.
[0092] In this implementation, subtractor 205 is used to determine the difference between the case temperature of the first power semiconductor device and the case temperature of the second power semiconductor device; comparator 202 is used to output a high-level signal when the difference is greater than a positive threshold and a low-level signal when the difference is less than a negative threshold. For example, when the case temperature of the first power semiconductor device is greater than that of the second power semiconductor device, the difference after subtraction is positive; when the case temperature of the first power semiconductor device is less than that of the second power semiconductor device, the difference after subtraction is negative. This allows for comparison with a positive threshold when the difference is positive and with a negative threshold when the difference is negative, thus determining the power semiconductor device with the highest case temperature when the difference between the case temperatures of the first and second power semiconductor devices is significant. Optionally, if the comparator determines that the difference is between the positive and negative thresholds, it can output a preset signal to indicate that the temperature difference between the first and second power semiconductor devices is within a reasonable range.
[0093] It should be noted that this application does not limit the connection method between the temperature sensor corresponding to the power semiconductor device and the positive and negative terminals of the input terminal of the subtractor. The principle is similar to the connection method described above, and will not be repeated here.
[0094] Similarly, when the hybrid switch 1021 includes two or more power semiconductor devices, the subtractor can output the difference with the largest absolute value. For example, considering a first power semiconductor device and two second power semiconductor devices, the two second power semiconductor devices are connected in series and then in parallel with the first power semiconductor device. Therefore, the subtractor can first determine the temperature difference 1 between the first power semiconductor device and the first second power semiconductor device, and the temperature difference 2 between the first power semiconductor device and the second second power semiconductor device. After determining the absolute values of difference 1 and difference 2, the difference with the larger absolute value is taken as the final output of the subtractor. This allows the comparator to determine whether the temperature difference between the two types of power semiconductor devices exceeds a reasonable range, and output the processing result.
[0095] In some possible implementations, Figure 8 A schematic diagram of another temperature control circuit provided in this application. Figure 8 As shown, the temperature control circuit 201 also includes a counter 206. The output of the comparator 202 is connected to the counter 206, and the counter 206 is connected to the control unit 101.
[0096] Counter 206 increments by one when a high-level signal is received and decrements by one when a low-level signal is received, then outputs the count value. For example, the counter can count the received level signals within each PWM signal cycle, incrementing by one when a high-level signal is received and decrementing by one when a low-level signal is received, then outputting the count value. In this implementation, the count value can represent the number of times within one cycle that the case temperature of the first power semiconductor device is greater than that of the second power semiconductor device, and the temperature difference between the two exceeds a reasonable range; alternatively, it can represent the number of times that the case temperature of the first power semiconductor device is less than that of the second power semiconductor device, and the temperature difference between the two exceeds a reasonable range.
[0097] Optionally, the counter value is reset to zero after each PWM signal cycle. This method allows for monitoring of the level signal within a cycle using a simple hardware structure.
[0098] In some possible implementations, the control unit 101 can use software to statistically analyze the level signal within a cycle and output a count value. This eliminates the need for a separate counter, reducing hardware costs.
[0099] Furthermore, the control unit 101 is specifically used to receive the count value output by the counter 206. When the count value is greater than a first value, it indicates that the case temperature of the first power semiconductor device has always been greater than that of the second power semiconductor device during this cycle, and the temperature difference between the two exceeds a reasonable range, meaning the high-temperature device is the first power semiconductor device, and thus the first power semiconductor device is controlled to disconnect. When the count value is less than a second value, it indicates that the case temperature of the first power semiconductor device has always been less than that of the second power semiconductor device during this cycle, and the temperature difference between the two exceeds a reasonable range, meaning the high-temperature device is the second power semiconductor device, and thus the second power semiconductor device is controlled to disconnect. In this way, the count value output by the counter can be adjusted in real time according to the comparator output during each control cycle of the PWM signal, and the switching state of the power semiconductor devices can be precisely controlled according to the count value. This reduces temperature fluctuations between power semiconductor devices in the hybrid switch, achieves dynamic temperature balance between power semiconductor devices in the hybrid switch during each cycle, reduces heat conduction between power semiconductor devices in the hybrid switch, thereby reducing the impact of the high-temperature device on the low-temperature device, improving the efficiency of the power semiconductor devices, and thus more effectively protecting the power devices and improving system performance.
[0100] In this embodiment, by setting a temperature control circuit with a subtractor, a comparator, a temperature sensor corresponding to the first power semiconductor device, and a temperature sensor corresponding to the second power semiconductor device, the case temperature of the first power semiconductor device and the case temperature of the second power semiconductor device in the hybrid switch can be collected based on the temperature sensors. The subtractor is used to determine the temperature difference between the case temperatures of the first and second power semiconductor devices. The comparator is used to determine whether the temperature difference exceeds a preset threshold. When the temperature difference exceeds the preset threshold, the processing result representing the power semiconductor device with the highest current case temperature is output. This allows the control unit to control the power semiconductor device with the highest current case temperature to disconnect based on the processing result.
[0101] This method first uses a subtractor to determine the temperature difference between the case temperatures of the first and second power semiconductor devices. Then, a comparator determines whether the temperature difference exceeds a reasonable range. This achieves temperature fluctuation identification of power semiconductor devices based on a relatively simple hardware structure, enabling the first and second power semiconductor devices to reach temperature equilibrium without relying on complex software programs, thus reducing system design difficulty and cost. Simultaneously, using a subtractor to monitor case temperature fluctuations can prevent damage to devices caused by excessive temperature fluctuations, reducing the possibility of system failures due to temperature issues.
[0102] Figure 9 A schematic diagram of the structure of an electric drive system provided in this application is shown below. Figure 9As shown, the electric drive system 300 includes a motor controller 100, a power supply 301, and a motor 302. The motor controller 100 is connected to the motor 302 and the power supply 301 respectively.
[0103] The motor controller 100 can invert the DC power output from the power supply 301 into three-phase AC power to control the motor 302. Simultaneously, during the DC-to-AC conversion process, the temperature control circuit within the motor controller can control the temperature of the power semiconductor devices in the hybrid power module, reducing heat conduction during operation, improving the efficiency of the hybrid power module, and consequently, improving the efficiency of the motor controller.
[0104] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the utility models disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.
[0105] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.
Claims
1. An electric motor controller characterized by, The motor controller includes: a control unit, multiple hybrid switches, and a temperature control circuit corresponding to each hybrid switch. Each hybrid switch includes a first power semiconductor device and a second power semiconductor device connected in parallel. The first power semiconductor device and the second power semiconductor device are of different types. The hybrid switch is connected to the control unit, and the temperature control circuit is connected to the control unit. The temperature control circuit is used to process the case temperature of each power semiconductor device in the hybrid switch corresponding to the temperature control circuit and output the processing result; wherein, the processing result represents the power semiconductor device with the highest current case temperature. The control unit is used to control the power semiconductor device with the highest current case temperature to disconnect based on the received processing result.
2. The motor controller of claim 1, wherein, The temperature control circuit includes a comparator, a temperature sensor corresponding to a first power semiconductor device, and a temperature sensor corresponding to a second power semiconductor device; the input terminal of the comparator is connected to the temperature sensor, and the output terminal of the comparator is connected to the control unit.
3. The motor controller of claim 2, wherein, The temperature sensor corresponding to the first power semiconductor device is connected to the positive terminal of the comparator's input, and the temperature sensor corresponding to the second power semiconductor device is connected to the negative terminal of the comparator's input. The comparator is configured to output a high-level signal when the case temperature of the first power semiconductor device is greater than that of the second power semiconductor device, and to output a low-level signal when the case temperature of the first power semiconductor device is less than that of the second power semiconductor device.
4. The motor controller of claim 2, wherein, The temperature control circuit also includes a subtractor, the input of which is connected to the temperature sensor, and the output of which is connected to the input of the comparator. The subtractor is used to determine the difference between the case temperature of the first power semiconductor device and the case temperature of the second power semiconductor device.
5. The motor controller of claim 4, wherein, The temperature sensor corresponding to the first power semiconductor device is connected to the positive terminal of the input of the subtractor, and the temperature sensor corresponding to the second power semiconductor device is connected to the negative terminal of the input of the subtractor; the positive terminal of the input of the comparator is connected to the output of the subtractor, and the negative terminal of the input of the comparator is a preset positive threshold and a preset negative threshold. The comparator is used to output a high-level signal when the difference is greater than the positive threshold. When the difference is less than the negative threshold, a low-level signal is output.
6. The motor controller of any one of claims 2-5, wherein, The comparator output includes a high-level signal and a low-level signal. The temperature control circuit also includes a counter. The output of the comparator is connected to the counter, and the counter is connected to the control unit. The counter is used to increment by one when the high-level signal is received, decrement by one when the low-level signal is received, and output the count value.
7. The motor controller of claim 6, wherein, The control unit is specifically used to receive the count value output by the counter, and when the count value is greater than a first value, control the first power semiconductor device to disconnect, and when the count value is less than a second value, control the second power semiconductor device to disconnect.
8. The motor controller of claim 1, wherein, The first power semiconductor device is a silicon device, and the second power semiconductor device is a silicon carbide device or a gallium nitride device.
9. The motor controller of claim 1, wherein, The motor controller further comprises a drive chip; the drive chip is connected with the control unit and the hybrid switch respectively.
10. An electric drive system characterized by comprising: The motor controller of any one of claims 1-9 is connected with the motor and the power supply respectively.