Power electronic device thermal management system with combined heating power and cold plate regulation

Abstract

The application provides a power electronic device thermal management system with combined regulation of heating power and refrigeration sheet, and the system comprises a micro driver, a signal acquisition circuit, a sensor, an upper computer, a power electronic device, a refrigeration sheet, a fan, a controlled current source and a controlled voltage source. The system calculates the real-time junction temperature fluctuation amplitude of the power electronic device according to the current and temperature of the power electronic device, and controls the switching frequency and current of the power electronic device to indirectly regulate the heating power of the power electronic device, and controls the input current of the refrigeration sheet to realize refrigeration or heating of the power electronic device, so that the junction temperature fluctuation of the power electronic device is effectively inhibited, and the problem of too fast aging speed of the power electronic device is solved, and the service life of the power electronic device is prolonged.

Description

Technical Field

[0001] This invention belongs to the field of thermal management of power electronic devices, and specifically relates to a thermal management system for power electronic devices that combines the regulation of heating power and cooling element. Background Technology

[0002] Power electronic devices are primarily used for power processing and conversion, and are widely applied in non-stationary operating conditions such as aerospace, industrial automation, transportation, and renewable energy generation. Under non-stationary conditions, the power processed by power converters fluctuates significantly and randomly, causing drastic changes in the junction temperature of power electronic devices. Because the thermal expansion coefficients of the materials in different layers of power electronic devices are inconsistent, junction temperature fluctuations cause different expansion rates between layers, generating thermal stress shocks that lead to aging and failure of the power electronic devices. Therefore, thermal management of power electronic devices is often implemented to reduce junction temperature fluctuations, thereby improving the expected lifespan of the devices.

[0003] Currently, thermal management methods for power electronic devices are mainly divided into passive thermal management and active thermal management. Passive thermal management, by reducing the thermal resistance of power electronic devices, can only simply prevent the junction temperature from becoming too high, and its effect on suppressing junction temperature fluctuations is not good. Compared with passive thermal management, active thermal management can reduce junction temperature fluctuations by adjusting the heat output of power electronic devices, but the adjustment method is singular. Thermal management methods that combine the regulation of ambient convection and heat output can further reduce junction temperature fluctuations; however, these methods all achieve this by lowering the junction temperature, and their ability to smooth junction temperature fluctuations is limited. Therefore, proposing a thermal management method that can both lower the junction temperature when it is too high and raise the junction temperature when it is too low, thereby reducing junction temperature fluctuations, is of great significance for extending the service life of power electronic devices. Summary of the Invention

[0004] The purpose of this invention is to provide a thermal management system for power electronic devices that combines heating power and cooling chip regulation, so as to improve the service life of power electronic devices.

[0005] The technical solution for realizing the present invention is: a power electronic device thermal management system for joint regulation of heating power and cooling chip, including a micro-driver, a sensor module, a signal acquisition circuit, a serial communication circuit, a host computer, a controlled current source, a controlled voltage source, power electronic devices, a cooling chip, and a cooling fan.

[0006] The sensor module is used for the current feedback value I of power electronic devices. ref-d Case temperature T of power electronic devices h-d The current feedback value I of the cooling chip ref-T The cold junction temperature T of the thermoelectric cooler c-T and cooling fan speed Vfw-fdb The signal is acquired and output as a voltage signal.

[0007] The sensor module is used to acquire the current feedback value I of the power electronic device. ref-d Case temperature T of power electronic devices h-d The current feedback value I of the cooling chip ref-T The hot end temperature T of the cooling element h-T The cold junction temperature T of the thermoelectric cooler c-T and cooling fan speed V fw-fdb All of the above signals are output to the signal acquisition circuit as voltage signals.

[0008] The signal acquisition circuit block is used to adjust the voltage signal output by the sensor module so that the voltage meets the safety threshold requirements of the micro-driver pin voltage, including the current feedback value I of the power electronic device. ref-d Signal acquisition circuits and the case temperature T of power electronic devices h-d The signal acquisition circuit and the current feedback value I of the cooling chip. ref-T Signal acquisition circuit, hot junction temperature T of the cooling chip h-T The signal acquisition circuit and the cold junction temperature T of the thermoelectric cooler. c-T Signal acquisition circuit and cooling fan speed V fw-fdb The signal acquisition circuit.

[0009] The host computer is used to set a reference value for the junction temperature fluctuation amplitude of power electronic devices. and reference value of thermoelectric current in Used to calculate the current limit value of power electronic devices. Used to calculate the switching frequency limit value of power electronic devices. Used to calculate the current limit value of the thermoelectric cooler. It is used to calculate wind speed reference values ​​and transmit them to the central controller via a serial communication circuit.

[0010] The controlled current source provides current to the thermoelectric cooler; a forward current causes the semiconductor to cool, while a reverse current causes it to heat. The cooling and heating efficiencies vary depending on the level of current applied to the thermoelectric cooler.

[0011] The controlled voltage source is used to supply voltage to the cooling fan. The output fan speed varies depending on the voltage level applied to it.

[0012] The micro-driver is used to receive a voltage signal output from the signal acquisition circuit containing current, wind speed, and temperature information, as well as a reference value for the junction temperature fluctuation amplitude set by the host computer. and The current feedback value I of the power electronic device is obtained by extracting the voltage signal. ref-d Case temperature T of power electronic devices h-d The current feedback value I of the cooling chip ref-T The cold junction temperature T of the thermoelectric cooler c-T and the cooling air velocity V of the thermoelectric cooler fw-fdb Based on the current feedback value I of the power electronic device ref-d and shell temperature T h-d Feedback value for calculating junction temperature fluctuation amplitude Feedback value of junction temperature fluctuation amplitude Reference value for junction temperature fluctuation amplitude and Closed-loop control for junction temperature fluctuation amplitude is used to generate current limit values ​​I for power electronic devices. lim_Tj and switching frequency f pwm1 Reference value of input current for the thermoelectric cooler and wind speed reference value Current limit value I of power electronic devices lim_Tj For a given desired current I h-d Saturation limiting and generating current reference value I. ob_d and. Current reference value I ob_d and current feedback value I ref-d Used for closed-loop control of current in power electronic devices, generating the first duty cycle D. pwm1 The cold junction temperature T of the thermoelectric cooler. c-T Reference value for the cold end temperature of the thermoelectric cooler The hot end temperature T of the thermoelectric cooler h-T Reference value for the hot end temperature of the thermoelectric cooler Closed-loop control of the thermoelectric cooler temperature generates a second duty cycle D. pwm2 Wind speed reference value and cooling fan speed V fw-fdb Closed-loop control for wind speed generates a third duty cycle D. pwm3 First duty cycle D pwm1 and switching frequency f pwm1 Used to generate the first PWM signal. Second duty cycle D pwm2 The third PWM signal is generated using the duty cycle of the three-phase motor. The final output consists of three PWM signals.

[0013] The first PWM signal is used to control the heating power of the power electronic device; the second PWM signal is used to control the output current of the controlled current source, thereby controlling the cooling or heating temperature of the thermoelectric cooler; and the third PWM signal is used to control the cooling fan speed of the thermoelectric cooler.

[0014] Compared with the prior art, the significant advantages of this invention are: this invention can reduce or increase the junction temperature of the device by adjusting the heating power and the cooling chip, thereby effectively smoothing junction temperature fluctuations, fully reducing the fatigue loss caused by junction temperature fluctuations to power devices, extending the operating life of power electronics, and reducing the operating and maintenance costs of the device. Attached Figure Description

[0015] Figure 1 This is a diagram of the thermal management system for a power converter.

[0016] Figure 2 The diagrams show current sensors and current acquisition circuits, where (a) is the first current sensor and the first current acquisition circuit, and (b) is the second current sensor and the second current acquisition circuit.

[0017] Figure 3 These are the thermistors and temperature acquisition circuit diagrams, where (a) is the first temperature sensor and the first temperature acquisition circuit diagram, (b) is the second temperature sensor and the second temperature acquisition circuit diagram, and (c) is the third temperature sensor and the third temperature acquisition circuit diagram.

[0018] Figure 4 This is a diagram of a wind speed sensor and its wind speed acquisition circuit.

[0019] Figure 5 This is a block diagram showing the combined adjustment and control of heating power and cooling element.

[0020] Figure 6 This is a model diagram of the junction thermal network of a power electronic device.

[0021] Figure 7 This is a thermal network model diagram of a thermoelectric cooler. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0023] The design challenge of this invention lies in how to design an active thermal management method for power electronic devices that coordinates the control of heat generation power and the external cooling capacity of the cooling chip on the temperature and temperature fluctuation characteristics of the power electronic devices, and in combination with the loss model of the power electronic devices, the thermal network model of the power electronic devices, and the thermal network model of the cooling chip.

[0024] like Figure 1 As shown, a power electronic device thermal management system that uses a combination of heating power and a cooling chip for regulation includes a micro-driver 1, a signal acquisition circuit 2, a sensor module 3, a serial communication module 4, a host computer 5, a controlled current source 6, a controlled voltage source 7, power electronic devices 8, a cooling chip 9, and a cooling fan 10.

[0025] The sensor module 3 is used for the current feedback value I of the power electronic device. ref-d Case temperature T of power electronic devices h-d The current feedback value I of the cooling chip ref-T The cold junction temperature T of the thermoelectric cooler c-T and cooling fan speed V fw-fdb The signal is acquired and output as a voltage signal.

[0026] The signal acquisition circuit 2 is used to adjust the voltage signal acquired by the sensor module 3 so that the acquired voltage meets the safety threshold requirements of the pin voltage of the micro-driver 1.

[0027] The serial communication module 4 is used to transmit the reference value of the junction temperature fluctuation amplitude from the host computer 5. and reference value of thermoelectric current Transfer to microdriver 1.

[0028] The controlled current source 6 is used to provide current to the thermoelectric cooler 9. When a forward current is applied, the semiconductor cools; when a reverse current is applied, the thermoelectric cooler heats. The cooling and heating efficiencies vary depending on the level of current applied to the thermoelectric cooler.

[0029] The controlled voltage source 7 is used to provide voltage to the cooling fan 10. The output fan speed varies depending on the voltage level applied to the cooling fan 10.

[0030] The micro-driver 1 is used to receive the voltage signal output by the signal acquisition circuit 2, which includes current, wind speed, and temperature information, and the reference value of the junction temperature fluctuation amplitude set by the host computer 5. and Output the first PWM, second PWM and third PWM signals.

[0031] The power electronic device 8 outputs power according to the first PWM signal output by the micro-driver 2; the controlled current source 6 is controlled by a PWM signal and controls the current of the cooling chip 9 according to the second PWM signal output by the micro-driver 2; the cooling chip 9 is used for cooling and heating of the power electronic device 8, and the cooling and heating effects are adjusted according to the control current output by the controlled current source 6; the controlled voltage source 7 is controlled by a PWM signal and controls the voltage of the cooling fan 9 according to the third PWM signal output by the micro-driver 2; the cooling fan 10 is used for heat dissipation of the cooling chip 9, and the cooling speed is adjusted according to the control voltage output by the controlled voltage source 7.

[0032] The sensor module 3 includes a first current sensor 3-1 for measuring the current feedback value I of the power electronic device 8. ref-d The second current sensor 3-2 is used to measure the current feedback value I of the cooling chip 9. ref-TThe first thermistor 3-3 is used to measure the case temperature T of the power electronic device 8. h-d The second thermistor 3-4 is used to measure the cold junction temperature T of the cooling chip. c-T The third thermistor, 3-5, is used to measure the hot-end temperature T of the cooling chip. h-T Wind speed sensors 3-6 are used to measure the cooling air velocity V of the thermoelectric cooler. fw-fdb .

[0033] The acquisition circuit 2 includes a first current acquisition circuit 2-1, a second current acquisition circuit 2-2, a first temperature acquisition circuit 2-3, a second temperature acquisition circuit 2-4, a third temperature acquisition circuit 2-5, and a wind speed acquisition circuit 2-6. The first current acquisition circuit 2-1 converts the voltage signal output by the first current sensor 3-1, and the second current acquisition circuit 2-2 converts the voltage signal output by the second current sensor 3-2. The first temperature acquisition circuit 2-3 converts the voltage signal output by the first thermistor 3-3, the second temperature acquisition circuit 2-4 converts the voltage signal output by the second thermistor 3-4, and the third temperature acquisition circuit 2-5 converts the voltage signal output by the third thermistor 3-5.

[0034] like Figure 2As shown, the first current acquisition circuit 2-1 includes a first voltage divider resistor 2-1-1, a first voltage regulating resistor 2-1-2, a first filter circuit 2-1-3, and a first pin protection circuit 2-1-4. One end of the first voltage divider resistor 2-1-1 is connected to the current sensor 2-1, and the other end is connected to the first voltage regulating resistor 2-1-2 and the first filter circuit 2-1-3, with connection point A1. The other end of the first voltage regulating resistor 2-1-2 is grounded. The other end of the first filter circuit 2-1-3 is connected to the AD pin of the micro-driver 2 and the first pin protection circuit 2-1-4. The first voltage divider resistor 2-1-1 and the first voltage regulating resistor 2-1-2 are connected to form a voltage divider circuit, ensuring that the voltage signal at the point is within the acquisition range of the micro-driver 2. Simultaneously, the resistance accuracy between the designed point and ground can be guaranteed by fine-tuning the first voltage regulating resistor. The first filter circuit filters the voltage signal at point A1, reducing signal interference. The first pin protection circuit prevents voltage spikes from damaging the micro-driver 2. The second current acquisition circuit 2-2 includes a second voltage divider resistor 2-2-1, a second voltage regulating resistor 2-2-2, a second filter circuit 2-2-3, and a second pin protection circuit 2-2-4. One end of the second voltage divider resistor 2-2-1 is connected to the current sensor 2-2, and the other end is connected to the second voltage regulating resistor 2-2-2 and the second filter circuit 2-2-3, connecting to point A2. The other end of the second voltage regulating resistor 2-2-2 is grounded. The other end of the second filter circuit 2-2-3 is connected to the AD pin of the micro-driver 1 and the second pin protection circuit 2-2-4. The second voltage divider resistor 2-2-1 and the second voltage regulating resistor 2-2-2 are connected to form a voltage divider circuit, so that the voltage signal at the point is within the range that the micro-driver 2 can collect. At the same time, the resistance accuracy between the designed point and ground can be ensured by fine-tuning the second voltage regulating resistor. The second filter circuit filters the voltage signal at point A2 to reduce signal interference. The second pin protection circuit prevents voltage spikes from damaging the micro-driver 2.

[0035] like Figure 3As shown, the first temperature acquisition circuit 2-3 includes a 3.3V power supply 2-3-1, a third voltage regulating resistor 2-3-2, and a third pin protection circuit 2-3-3. One end of the third voltage regulating resistor 2-3-2 is connected to the connection point A3 of the first thermistor 3-3, and the other end is grounded. One end of the first thermistor 3-3 is connected to the 3.3V power supply 2-3-1, and the other end of the first thermistor 3-3 is connected to the AD pin of the microdriver 1 and the third pin protection circuit 2-3-3. The third voltage regulator 2-3-2 and the first thermistor 3-3 are connected to form a voltage divider circuit, ensuring that the voltage signal at point A3 is within the acquisition range of the microdriver 2. Simultaneously, the resistance accuracy requirements at both ends of the third voltage regulator 2-3-2 can be met by fine-tuning it. The third pin protection circuit 2-3-3 prevents voltage spikes from damaging the microdriver 2. The second temperature acquisition circuit 2-4 includes a 3.3V power supply 2-4-1, a fourth voltage regulator 2-4-2, and a fourth pin protection circuit 2-4-3. One end of the fourth voltage regulator 2-4-2 is connected to the connection point A4 of the second thermistor 3-4, and the other end is grounded. One end of the second thermistor 3-4 is connected to the 3.3V power supply 2-4-1, and the other end is connected to the AD pin of the microdriver 1 and the fourth pin protection circuit 2-4-3. The fourth voltage regulator 2-4-2 and the second thermistor 3-4 are connected to form a voltage divider circuit, ensuring that the voltage signal at point A4 is within the acquisition range of the microdriver 2. Simultaneously, the resistance accuracy requirements at both ends of the fourth voltage regulator 2-4-2 can be met by fine-tuning it. The fourth pin protection circuit 2-4-3 prevents voltage spikes from damaging the microdriver 2. The third temperature acquisition circuit 2-5 includes a 3.3V power supply 2-5-1, the fourth voltage regulator 2-5-2, and the fourth pin protection circuit 2-5-3. One end of the fourth voltage regulator 2-5-2 is connected to the connection point A5 of the third thermistor 3-5, and the other end is grounded. One end of the third thermistor 3-5 is connected to the 3.3V power supply 2-5-1, and the other end is connected to the AD pin of the microdriver 2 and the fifth pin protection circuit 2-5-3. The fifth voltage regulator 2-5-2 and the third thermistor 3-5 are connected to form a voltage divider circuit, so that the voltage signal at point A5 is within the range that the micro-driver 1 can acquire. At the same time, the fifth voltage regulator 2-5-2 can be finely adjusted to meet the resistance accuracy requirements at both ends of the fifth voltage regulator 2-5-2. The fifth pin protection circuit 2-5-3 prevents voltage spikes from damaging the micro-driver 1.

[0036] like Figure 4As shown, the wind speed acquisition circuit 2-6 includes a sixth voltage divider resistor 2-6-1, a sixth voltage regulating resistor 2-6-2, a sixth filter circuit 2-6-3, and a sixth pin protection circuit 2-6-4. One end of the sixth voltage divider resistor 2-6-1 is connected to the wind speed sensor 3-6, and the other end is connected to the sixth voltage regulating resistor 2-6-2 and the sixth filter circuit 2-6-3, with the connection point being V6. The other end of the sixth voltage regulating resistor 2-6-2 is connected to ground, and the other end of the sixth filter circuit 2-6-3 is connected to the AD pin of the micro-driver 2 and the sixth pin protection circuit 2-6-4. The sixth voltage divider resistor 2-6-1 and the sixth voltage regulator resistor 2-6-2 are connected to form a voltage divider circuit, so that the voltage signal at point V6 is within the range that the micro-driver 2 can acquire. At the same time, the resistance value between point V6 and ground can be ensured by fine-tuning the sixth voltage regulator resistor 2-6-2. The sixth filter circuit 2-6-3 filters the voltage signal at point V6 to reduce signal interference. The sixth pin protection circuit 2-6-4 prevents voltage spikes from damaging the micro-driver 2.

[0037] like Figure 5 As shown, the micro-driver 1 includes a signal acquisition module 1-1, a power device loss model 1-2, a junction-shell thermal network model 1-3, a cooling chip thermal network model 1-4, a low-pass filter 1-5, a first current limiting controller 1-6, a frequency limiting controller 1-7, a second current limiting controller 1-8, a wind speed limiting controller 1-9, a current limiting module 1-10, a current PI controller 1-11, a pulse width modulation module 1-12, a semiconductor cooling control module 1-13, and a wind speed control module 1-14.

[0038] The signal acquisition module 1-1 is used to acquire the current feedback value I of the power electronic device. ref-d Case temperature T of power electronic devices h-d The current feedback value I of the cooling chip ref-T The cold junction temperature T of the thermoelectric cooler c-T and cooling fan speed V fw-fdb , as the acquisition quantity of micro-driver 1.

[0039] The power electronic device loss model 1-2 is used to calculate the device loss power P. loss The power device P loss The junction temperature feedback value T for power devices is used in the junction-shell thermal network model 1-3. j Given the conditions at time. The calculation process is as follows:

[0040] The current feedback value I of the power device ref-d The switching frequency f(k-1) and junction temperature feedback value T at the previous moment j Substituting into formula (1), the power loss P of the power device can be calculated. loss ;

[0041]

[0042] Where I represents the power device current, and the current feedback value I of the power device is used in the calculation. ref-d f is the switching frequency of the power device, and the switching frequency f(k-1) from the previous moment is used in the calculation. j For the junction temperature of the power device, the junction temperature feedback value T from the previous moment is used in the calculation. j (k-1), p a,b,c The coefficients are the fitting coefficients, where a, b, and c are the exponents of the power electronic device current, the power electronic device switching frequency, and the power electronic device junction temperature, respectively, and n represents the highest order of fitting.

[0043] The junction-shell thermal network models 1-3 are used to calculate the junction temperature feedback value T of the power device. j ;like Figure 6 The aforementioned crust thermal network models 1-3 adopt a second-order Cauer structure model, where P loss The power loss P of power electronic devices loss T j T is the junction temperature of power electronic devices. h-d The case temperature T of power electronic devices h-d T1 is the temperature of node 1 in the thermal network between the junction and the shell. C1 is the heat capacity of node 1 and node 2 in the thermal network. R1 is the thermal resistance of node 1 and node 2 in the thermal network. The values ​​are provided in the power datasheet. Substituting these values ​​into formulas (2) and (3), the junction temperature feedback value T of the power device is calculated. j .

[0044]

[0045]

[0046] Among them, T j (k) represents the junction temperature feedback value of the power electronic device to be determined at the current moment, and T1(k) represents the temperature of node 1 of the thermal network between the junction and the shell at the current moment. j (k-1) represents the junction temperature at the previous moment, T1(k-1) represents the temperature of node 1 in the thermal network between the junction and the shell at the previous moment, and T c (k) represents the current case temperature of the power device. The case temperature T of the power device is used in the calculation. h-d P(k) represents the power loss of the power device at the current moment, and the power loss P of the power device is used in the calculation. loss Δt is the discrete time.

[0047] The thermal network models 1-4 of the cooling chip are used to calculate the cold end temperature feedback value T of the cooling chip. c-Tand hot end temperature feedback value T h-T The calculation process is as follows:

[0048] like Figure 7 As shown, the thermal network model of the refrigeration chip is shown, where I ref-T T is the current feedback value of the thermoelectric cooler. j Here, α represents the junction temperature of the power electronic device, α represents the Seebeck coefficient of the thermoelectric cooler, C3 represents the heat capacity at the cold end of the thermoelectric cooler, C4 represents the heat capacity at the hot end of the thermoelectric cooler, R3 represents the thermal resistance of the power electronic device, R4 represents the thermal resistance of the thermoelectric cooler, R5 represents the internal resistance of the thermoelectric cooler, and T represents the junction temperature of the power electronic device. a (k-1) represents the ambient temperature at the previous moment, and the current feedback value I of the cooler is... ref-T Substituting into formulas (4)-(7), the cold end temperature T of the thermoelectric cooler is calculated. c-T and hot end temperature T h-T .

[0049]

[0050]

[0051]

[0052]

[0053] Among them, T c (k) represents the current cold junction temperature of the thermostat to be determined, T h (k) represents the current temperature of the hot end of the thermoelectric cooler, and Q1(k) represents the current feedback value of the input thermoelectric cooler current I. ref-T The heat generated at the cooling end, Q2(k), is the current feedback value I of the input thermocouple current at the current moment. ref-T The heat generated at the hot end, T c (k-1) represents the cold end temperature of the thermoelectric cooler at the previous time, T h (k-1) represents the previous temperature value of the hot end of the cooling chip.

[0054] The low-pass filters 1-5 obtain the average junction temperature T through filtering. jm Junction temperature feedback value T of power electronic devices j With the average junction temperature T jm The feedback value ΔT of the junction temperature fluctuation amplitude is obtained by subtraction. j .

[0055] The current limiting controllers 1-6 are used to calculate the output current limiting value I. lim_Tj This value is used for a given desired current I. h-d Saturation limiting yields the current reference value I. ob_d The calculation process is as follows:

[0056] Output a reference value based on the set junction temperature fluctuation amplitude. The difference ΔT between the feedback value and the junction temperature fluctuation amplitude j Control output current limit value I lim_Tj .

[0057] The frequency limiting controllers 1-7 are used to adjust the switching frequency f. pwm1 The reference value for the junction temperature fluctuation amplitude With feedback value ΔT j The difference is calculated and input into the frequency limiting controllers 1-7. A hysteresis control algorithm is then used to adjust the switching frequency f. pwm1 Adjustments were made.

[0058] The current limiting controllers 1-8 for the cooling chip are used to adjust the output current reference value. Reference value of junction temperature fluctuation amplitude Feedback value ΔT of junction temperature fluctuation amplitude j Adjust the output current reference value based on the difference between them.

[0059] The wind speed limiting controllers 1-9 are used to control the wind speed reference value. Reference value of the hot end temperature of the thermoelectric cooler Feedback value T with hot end temperature c-T The difference between the two values ​​is input into the wind speed limiting controllers 1-9, which use a PI control algorithm to control the output wind speed reference value.

[0060] The current limiting module 1-10 sets the current limiting value I. lim_Tj As an upper limit, for a given desired current I h-d Saturation limiting yields the current reference value I. ob_d The specific process is as follows: compare the current limit value I. lim_Tj With the desired current I h-d The smaller of the values ​​is used as the output current reference value.

[0061] The current PI controller 1-11 is used to calculate the duty cycle D of the first PWM signal. pwm1 The specific process is as follows: The current feedback value I of the power electronic device... ref-d With current reference value I ob_d The difference is calculated and input into the current PI controller 1-11 to calculate the duty cycle D of the first PWM signal. pwm1 .

[0062] The cooling chip control module 1-12 is used to calculate the duty cycle D of the second PWM signal. pwm2 Specifically, it consists of: setting the cold end temperature reference value of the cooling chip. Feedback value T with cold junction temperature c-T The difference is calculated and input into the thermoelectric cooler control module 1-12 to calculate the duty cycle D of the second PWM signal. pwm2 .

[0063] The wind speed control modules 1-13 are used to calculate the duty cycle D of the third PWM signal. pwm3 Wind speed reference value With cooling fan speed V fw-fdb The difference is calculated and input into the wind speed control module 1-13 to calculate the duty cycle D of the third PWM signal. pwm3 .

[0064] The pulse width modulation modules 1-14 generate a first PWM signal, a second PWM signal, and a third PWM signal. Based on the switching frequency f... pwm1 and the first duty cycle D pwm1 Second duty cycle D pwm2 Third duty cycle D pwm3 The parameters of the microdriver's built-in PWM signal generation module are set to generate the first PWM signal, the second PWM signal, and the third PWM signal, which are then output by the microdriver 1.

Claims

1. A thermal management system for power electronic devices with combined regulation of heating power and cooling element, characterized in that: Includes sensor modules, signal acquisition circuits, serial communication circuits, host computer, micro-drivers, controlled current sources, controlled voltage sources, power electronic devices, thermoelectric coolers, and cooling fans; The sensor module is used to collect the current feedback value of the power electronic device. Case temperature of power electronic devices Current feedback value of the cooling chip The hot end temperature of the cooling element The cold junction temperature of the thermoelectric cooler and cooling fan speed All of the above signals are output to the signal acquisition circuit as voltage signals; The signal acquisition circuit block is used to adjust the voltage signal output by the sensor module so that the voltage meets the safety threshold requirements of the micro-driver pin voltage, including the current feedback value of the power electronic device. Signal acquisition circuits and case temperature of power electronic devices The signal acquisition circuit and the current feedback value of the cooling chip Signal acquisition circuit, hot junction temperature of the cooling chip The signal acquisition circuit and the cold junction temperature of the thermoelectric cooler. Signal acquisition circuit and cooling fan speed The signal acquisition circuit; The host computer is used to set a reference value for the junction temperature fluctuation amplitude of power electronic devices. , , and reference value of thermoelectric current ,in Used to calculate the current limit value of power electronic devices. Used to calculate the switching frequency limit value of power electronic devices. Used to calculate the current limit value of the thermoelectric cooler. It is used to calculate wind speed reference values ​​and transmit them to the central controller via a serial communication circuit. The controlled current source is used to provide current to the thermoelectric cooler. When a positive current is applied, the semiconductor cools; when a reverse current is applied, the thermoelectric cooler heats. The cooling and heating efficiencies vary depending on the level of current applied to the thermoelectric cooler. The controlled voltage source is used to provide voltage to the cooling fan; the output fan speed varies depending on the voltage level applied to the cooling fan. The micro-driver is used to receive a voltage signal output from the signal acquisition circuit, which includes information on current, wind speed, and temperature, as well as a reference value for the junction temperature fluctuation amplitude set by the host computer. , , ,and The current feedback value of the power electronic device is obtained by extracting the voltage signal. Case temperature of power electronic devices Current feedback value of the cooling chip The cold junction temperature of the thermoelectric cooler and the cooling airflow of the thermoelectric element Based on the current feedback value of the power electronic device and shell temperature Feedback value for calculating junction temperature fluctuation amplitude Feedback value of junction temperature fluctuation amplitude Reference value for junction temperature fluctuation amplitude , , ,and Closed-loop control for junction temperature fluctuation amplitude is used to generate current limit values ​​for power electronic devices. and switching frequency Reference value of input current for the thermoelectric cooler and wind speed reference value Current limit values ​​for power electronic devices For a given desired current Saturation limiting and generation of current reference value. and current feedback value Current reference value and current feedback value Used for closed-loop control of current in power electronic devices, generating the first duty cycle. Cold junction temperature of the thermoelectric cooler Reference value for the cold end temperature of the thermoelectric cooler Closed-loop control of the thermoelectric cooler temperature generates a second duty cycle. ; Wind speed reference value and cooling fan speed For closed-loop control of wind speed, a third duty cycle is generated. First duty cycle and switching frequency Used to generate the first PWM signal; second duty cycle The third duty cycle is used to generate the second PWM signal; the third duty cycle is used to generate the third PWM signal, and finally three PWM signals are output. The first PWM signal is used to control the heating power of the power electronic device; the second PWM signal is used to control the output current of the controlled current source, thereby controlling the cooling or heating temperature of the thermoelectric cooler; and the third PWM signal is used to control the cooling fan speed of the thermoelectric cooler. The micro-actuator includes a signal acquisition module, a power electronic device loss model, a power electronic device junction-shell thermal network model, a thermoelectric thermal network model, a low-pass filter, a power electronic device current limiting controller, a frequency limiting controller, a thermoelectric current limiting controller, a wind speed limiting controller, a current limiting module current PI controller, a pulse width modulation module, a thermoelectric controller module, and a wind speed control module. The signal acquisition module is used to obtain the cooling fan speed. Cold junction temperature of the thermoelectric cooler Hot end temperature Case temperature of power electronic devices and current feedback value , as the acquisition quantity of the micro-actuator; The power electronic device loss model is based on the current feedback value of the power electronic device. The junction temperature feedback value a moment ago Calculate the power loss of power electronic devices ; The junction-shell thermal network model of the power electronic device is based on the power loss of the power electronic device. and shell temperature Calculate the junction temperature feedback value of the output power electronic device. This value serves as the filtering target for the low-pass filter and is also used to calculate the feedback value for the junction temperature fluctuation amplitude. ; The thermal network model of the cooling chip is based on the input current of the cooling chip. Calculate and output the cold junction temperature of the thermostat. and hot end temperature feedback value ; The low-pass filter uses the junction temperature feedback value of the power device. Filtering yields the average junction temperature. Junction temperature feedback value of power electronic devices With average junction temperature The feedback value of the junction temperature fluctuation amplitude is obtained by subtraction. ; The power electronic device current limiting controller is based on a reference value set for the junction temperature fluctuation amplitude. The difference between the feedback value and the junction temperature fluctuation amplitude Control output current limit value ; The frequency limiting controller is based on a reference value set for the junction temperature fluctuation amplitude. Feedback value of junction temperature fluctuation amplitude The difference between them controls the output switching frequency. ; The current limiting controller for the cooling chip is based on a reference value set for the junction temperature fluctuation amplitude. Feedback value of junction temperature fluctuation amplitude The difference between them controls the reference value of the output current. ; The wind speed limiting controller is based on a reference value of the hot end temperature of the cooling element. Feedback value of hot end temperature The difference between them controls the output wind speed reference value. ; The current limiting module limits the current value. As an upper limit, for a given desired current Saturation limiting is used to obtain the current reference value. ; The current PI controller uses the current reference value. With current feedback value The difference between them controls the first duty cycle of the first PWM signal output. ; The cooling chip control module uses the reference value of the cold end temperature of the cooling chip. With cold end temperature The difference between them is used to calculate the second duty cycle of the second PWM signal. ; The wind speed control module is based on the wind speed reference value. With cooling fan speed The difference between them is used to calculate the third duty cycle of the third PWM signal. ; The pulse width modulation module is based on the switching frequency. and first duty cycle Second duty cycle Third duty cycle The parameters of the microdriver's built-in PWM signal generation module are set to generate the first PWM signal, the second PWM signal, and the third PWM signal, which are used as the output of the microdriver. Power electronic device loss model calculation of device power loss The process is as follows: The current feedback value of the power device The switching frequency at the previous moment and junction temperature feedback value Substituting into formula (1), the power loss of the power device can be calculated. ; （1） Where I represents the power device current, which is the current feedback value of the power device used in the calculation. , The switching frequency of the power device is used in the calculation; the switching frequency at the previous moment is used. , For the junction temperature of power devices, the junction temperature feedback value from the previous moment is used in the calculation. , The coefficients are the fitting coefficients, where a, b, and c are the exponents of the power electronic device current, the power electronic device switching frequency, and the power electronic device junction temperature, respectively, and n represents the highest order of fitting. The junction-shell thermal network model is used to calculate the junction temperature feedback value of the power device. The calculation process is as follows: Power loss of power electronic devices Case temperature of power electronic devices Substituting into equations (2) and (3), the junction temperature feedback value of the power device is calculated. : （2） （3） in, This is the junction temperature feedback value of the power electronic device at the current moment. The temperature of node 1 in the thermal network between the crusts at the current moment. This is the junction temperature value from the previous moment. The temperature of node 1 in the thermal network between the shells at the previous moment. The current case temperature of the power device is used in the calculation. , The power loss of the power device at the current moment is used in the calculation. , For discrete time, C1 represents the heat capacity of thermal network node 1, C2 represents the heat capacity of thermal network node 2, R1 represents the thermal resistance of thermal network node 1, and R2 represents the thermal resistance of thermal network node 2, all provided by the power manual.

2. The power electronic device thermal management system with combined regulation of heating power and cooling element as described in claim 1, characterized in that, The thermal network model of the thermoelectric cooler is used to calculate the cold junction temperature feedback value of the thermoelectric cooler. and hot end temperature feedback value The calculation process is as follows: Feedback value of the current of the cooling chip Substituting into equations (4)-(7), the cold end temperature of the thermoelectric cooler is calculated. and hot end temperature : （4） （5） （6） （7） in, The desired value is the cold junction temperature of the thermostat at the current moment. This represents the current hot-end temperature of the thermoelectric cooler. Input the current feedback value of the thermoelectric cooler at the current moment. The heat generated at the cold end, Input the current feedback value of the thermoelectric cooler at the current moment. The heat generated at the hot end, This is the cold junction temperature of the thermoelectric cooler at the previous moment. This is the previous hot-end temperature value of the thermoelectric cooler. R represents the Seebeck coefficient of the thermoelectric cooler; C3 represents the heat capacity at the cold end of the cooler; C4 represents the heat capacity at the hot end of the cooler; R3 represents the thermal resistance of the power electronic device; R4 represents the thermal resistance of the thermoelectric cooler; and R5 represents the internal resistance of the thermoelectric cooler. The ambient temperature at the moment before.

3. The power electronic device thermal management system with combined regulation of heating power and cooling element as described in claim 2, characterized in that, The micro-driver outputs three PWM signals. The first PWM signal controls the output power of the power electronic device, thereby regulating the heating power of the power device. The third PWM signal controls the current of the controlled current source, thereby controlling the cold and hot junction temperatures of the thermoelectric cooler, and regulating the cooling and heating capabilities of the power electronic device. The fourth PWM signal controls the voltage of the controlled power supply, further controlling the cooling fan speed, and regulating the ambient convection cooling capability of the thermoelectric cooler. By coordinating the heating power of the power electronic device and the cooling and heating capabilities of the thermoelectric cooler, the junction temperature of the power electronic device is smoothed.

4. The power electronic device thermal management system with combined regulation of heating power and cooling element as described in claim 1, characterized in that, The signal acquisition circuit includes a current acquisition circuit, a temperature acquisition circuit, and a wind speed acquisition circuit; the current acquisition circuit is used to convert the voltage signal output by the current sensor, the temperature acquisition circuit is used to convert the voltage signal output by the temperature sensor, and the wind speed acquisition circuit is used to convert the voltage signal output by the wind speed sensor.

5. The power electronic device thermal management system with combined regulation of heating power and cooling element according to claim 4, characterized in that, The current acquisition circuit includes a first voltage divider resistor, a first voltage regulating resistor, a first filter circuit, and a first pin protection circuit. One end of the first voltage divider resistor is connected to the current sensor, and the other end is connected to the first voltage regulating resistor and the first filter circuit. The other end of the first voltage regulating resistor is grounded, and the other end of the first filter circuit is connected to the AD pin of the micro-driver and the first pin protection circuit. The first voltage divider resistor and the first voltage regulating resistor are connected to form a voltage divider circuit.

6. The power electronic device thermal management system with combined regulation of heating power and cooling element as described in claim 5, characterized in that, The temperature acquisition circuit includes a power supply, a second voltage regulating resistor, a second filter circuit, and a second pin protection circuit. One end of the second voltage regulating resistor is connected to a thermistor and the second filter circuit, the other end of the second voltage regulating resistor is connected to the power supply, the other end of the thermistor is connected to ground, and the other end of the second filter circuit is connected to the AD pin of the microdriver and the second pin protection circuit. The second voltage regulating resistor and the thermistor are connected to form a voltage divider circuit.

7. The power electronic device thermal management system with combined regulation of heating power and cooling element as described in claim 6, characterized in that, The wind speed acquisition circuit includes a second voltage divider resistor, a third voltage regulating resistor, a third filter circuit, and a third pin protection circuit. One end of the second voltage divider resistor is connected to the wind speed sensor, and the other end of the second voltage divider resistor is connected to the third voltage regulating resistor and the third filter circuit. The other end of the second voltage regulating resistor is connected to ground, and the other end of the third filter circuit is connected to the AD pin of the micro-driver and the third pin protection circuit. The second voltage divider resistor and the third voltage regulating resistor are connected to form a voltage divider circuit.

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