IGBT module protection system for new energy commercial vehicle

Abstract

The utility model discloses an IGBT module protection system for a new energy commercial vehicle. The IGBT module protection system comprises an IGBT module, a PWM driving interlocking module, a driving overvoltage and undervoltage protection module, an overcurrent protection module, a short-circuit protection module and an over-temperature overload protection module. The IGBT module protection system detects the current and temperature of the IGBT module through software to carry out overcurrent, overload and over-temperature protection so as to deal with damage caused by long-time heat accumulation of the IGBT module, and hardware integrates PWM interlocking, driving VGE overvoltage and undervoltage, output overcurrent and VCE desaturation detection to deal with damage caused by excessive instantaneous loss.

Description

Technical Field

[0001] This utility model belongs to the technical field of IGBT module protection system, and relates to an IGBT module protection system for new energy commercial vehicles. Background Technology

[0002] As a core component of new energy vehicle controllers, IGBT modules are crucial for vehicle safety. Damage to an IGBT module can render the vehicle inoperable. Therefore, monitoring its operational status and providing appropriate protection against abnormal conditions is essential for safety. IGBT module failure is often caused by excessively high junction temperatures within the IGBT chip, leading to heat accumulation. This process can be divided into short-term and long-term accumulation. Short-term accumulation typically occurs under short-circuit conditions (10µs, generally five times the rated current) and overcurrent conditions (1ms, twice the rated current). Long-term accumulation occurs under overload conditions. Summary of the Invention

[0003] To address the problems existing in the background technology, this utility model proposes an IGBT module protection system for new energy commercial vehicles. By using IGBT module protection as a systematic strategy in new energy commercial vehicles, and through IGBT status monitoring and abnormal state protection, the risk of IGBT module damage can be significantly reduced.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0005] A protection system for IGBT modules in new energy commercial vehicles includes: an IGBT module, a PWM drive interlock module, a drive over / under voltage protection module, an overcurrent protection module, a short circuit protection module, and an over-temperature / overload protection module;

[0006] The first end of the PWM drive interlock module is connected to the second end of the over-temperature and overload protection module, the second end of the PWM drive interlock module is connected to the first end of the drive over-voltage and under-voltage protection module, the third end of the PWM drive interlock module is connected to the second end of the overcurrent protection module, the first end of the IGBT module is connected to the second end of the drive over-voltage and under-voltage protection module and the second end of the short-circuit protection module, the second end of the IGBT module is connected to the first end of the over-temperature and overload protection module, and the third end of the IGBT module is connected to the first end of the overcurrent protection module and the first end of the short-circuit protection module.

[0007] Furthermore, the drive over / under voltage protection module includes a drive over / under voltage protection circuit and an IGBT drive module, wherein the drive over / under voltage protection circuit is connected to the first terminal of the IGBT drive module;

[0008] The PWM drive interlock module is a DSP module, and the first terminal of the DSP module is connected to the second terminal of the IGBT drive module.

[0009] The overcurrent protection module includes a Hall current sampling module and a hardware overcurrent comparison module;

[0010] The first terminal of the Hall current sampling module is connected to the third terminal of the IGBT module, the second terminal of the Hall current sampling module is connected to the second terminal of the hardware overcurrent comparison module, and one terminal of the hardware overcurrent comparison module is connected to the second terminal of the DSP module.

[0011] The short-circuit protection module includes a short-circuit circuit. The first terminal of the short-circuit circuit is connected to the first terminal of the IGBT module and the third terminal of the IGBT drive module. The second terminal of the short-circuit circuit is connected to the third terminal of the IGBT module and the first terminal of the Hall current sampling module.

[0012] The over-temperature and overload protection module includes an IGBT temperature sampling module, which includes a thermistor NTC. The first terminal of the IGBT temperature sampling module is connected to the second terminal of the IGBT module, and the second terminal of the IGBT temperature sampling module is connected to the third terminal of the DSP module.

[0013] Furthermore, the IGBT module includes a thermistor NTC.

[0014] Furthermore, the DSP module includes a PWM output port and The IGBT driver module includes a first driver and a second driver. Each driver has an IP port, an IN port, and an output port.

[0015] The PWM output port is connected to the IP port of the first driver and the IN port of the second driver. The output port is connected to the IN port of the first driver and the IP port of the second driver;

[0016] The PWM output port outputs a PWM signal. Output port output Signals, PWM signals and The signals are a pair of complementary signals with dead time. When the PWM signal and When the signal is interfered with, a PWM signal appears and When both signals are at a high level, the outputs of the upper and lower bridge arms of the IGBT module enter an interlocked mode.

[0017] Furthermore, the hardware overcurrent comparison module includes a fourth comparator COMP3 and a Vref port;

[0018] The second terminal of the Hall current sampling module is connected to the inverting input terminal of the fourth comparator COMP3, the non-inverting input terminal of the fourth comparator COMP3 is connected to the Vref port, and the output terminal of the fourth comparator COMP3 is connected to the TZ6 pin of the DSP module.

[0019] The IGBT module's output current is converted into a voltage signal by a Hall current sampling module. This voltage signal is compared to the reference voltage Vref of the fourth comparator COMP3. If the voltage exceeds the reference voltage Vref threshold, the fourth comparator COMP3 reverses, the DSP module reports a hardware overcurrent fault, and simultaneously disables the drive PWM signal. Signal;

[0020] The DSP module pre-sets a safe current threshold as a supplement to the hardware overcurrent comparison protection module in case of failure. The hardware overcurrent comparison protection module detects overcurrent signals as spikes. After the current acquisition in the overcurrent signal is filtered, the DSP module is more sluggish in its response to spike overcurrent signals. When the hardware overcurrent protection fails, protection is provided by pre-setting a safe current threshold in the DSP module.

[0021] Furthermore, the drive over- and under-voltage protection circuit includes diodes D2, D3, and D4, resistors R1, R2, and R3, transistors Q2 and Q3, a first comparator AMP1, a second comparator COMP1, a third comparator COMP2, a Vref1 port, and a Vref2 port.

[0022] The non-inverting input of the first comparator AMP1 is connected to the collector of transistor Q2 and the cathode of diode D4. The base of transistor Q2 is connected to the base of transistor Q3. The emitter of transistor Q2 is connected to the collector of transistor Q3 and one end of resistor R1. The other end of resistor R1 is connected to the anode of diode D4, the cathode of diode D2, and the IGBT driver module. The anode of diode D2 is connected to the anode of diode D3. The cathode of diode D3 is connected to the inverting input of the first comparator AMP1, the emitter of transistor Q3, and the IGBT module pin U_L_E. One end of resistor R2 is connected to the 5V power supply and resistor R3. The other end of resistor R2 is connected to the TZ3 pin of the DSP module and the output of the third comparator COMP2. The other end of resistor R3 is connected to the TZ4 pin of the DSP module and the output of the second comparator COMP1. The inverting input of the second comparator COMP1 is connected to the Vref1 port. The non-inverting input of the second comparator COMP1 is connected to the output of the first comparator AMP1 and the inverting input of the third comparator COMP2. The non-inverting input of the third comparator COMP2 is connected to the Vref2 port.

[0023] When the collector voltage of transistor Q2 is lower than the reference voltage Vref1, the second comparator COMP1 will reverse; when the collector voltage of transistor Q2 is higher than the reference voltage Vref2, the third comparator COMP2 will reverse. Comparators COMP1 and COMP2 are push-pull outputs. The TZ4 pin of the DSP module transmits a drive undervoltage lockout fault signal, and the TZ3 pin transmits a drive overvoltage lockout fault signal. Upon receiving or transmitting a drive undervoltage lockout fault signal, the DSP module immediately shuts down the drive PWM signal. Signal, and upload driver undervoltage lockout fault.

[0024] Furthermore, the short-circuit protection circuit includes: resistor R4, diode D1, diode D5, transistor Q4, capacitor C1, Vref3 port, fifth comparator COMP4, VCE desaturation port, and TIs port;

[0025] The cathode of diode D4 is connected to the non-inverting input of the fifth comparator COMP4, the drain of transistor Q4, the input of capacitor C1, and the input of resistor R4. The inverting input of the fifth comparator COMP4 is connected to the Vref3 port. The output of the fifth comparator COMP4 is connected to the VCE desaturation port. The gate of transistor Q4 is connected to the cathode of diode D5. The TIs port is connected to the anode of diode D5 and the IGBT driver module. The source of transistor Q4 is connected to the output of capacitor C1 and the U_L_E pin of the IGBT module. The output of resistor R1 is connected to the anode of diode D1. The cathode of diode D1 is connected to the U_L_C pin of the IGBT module.

[0026] When a short circuit occurs, the voltage across the IGBT module rises, and the voltage at the non-inverting input of the fifth comparator COMP4 also rises. When the voltage at the non-inverting input of the fifth comparator COMP4 exceeds the reference voltage Vref3, the fifth comparator COMP4 is triggered, outputting a Vce desaturation signal. Upon detecting the Vce desaturation signal, the DSP module will disable the drive PWM signal and... The signal simultaneously transmits a short-circuit fault.

[0027] Furthermore, the IGBT temperature sampling module is connected to the thermistor NTC;

[0028] The IGBT temperature sampling module converts the resistance change of the thermistor (NTC) into a voltage signal. The DSP module acquires the temperature of the IGBT module, and the junction temperature is estimated using a thermal impedance model to determine the temperature of the IGBT module chip and diodes. The formula for calculating the junction temperature using the thermal impedance model is as follows: ,in This represents the total loss of the IGBT module. Here, TC represents the thermal resistance from junction temperature to case temperature. When the estimated junction temperature exceeds the IGBT module's junction derating value, an over-temperature fault will be triggered, limiting power or shutting down the system.

[0029] As a supplement to over-temperature protection, the IGBT module overload protection limits the IGBT power through the DSP module to further protect the IGBT module's operating junction temperature from falling below the maximum junction temperature derating value.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The IGBT module protection system uses software to detect the current and temperature of the IGBT module for overcurrent, overload, and overtemperature protection, addressing damage caused by prolonged heat accumulation. Hardware integration includes PWM interlocking, VGE over / under voltage detection, output overcurrent detection, and VCE desaturation detection to handle damage caused by excessive instantaneous power loss. By incorporating IGBT module protection as a system solution, it identifies and protects against various abnormal operating conditions, significantly reducing the risk of damage even when the IGBT module malfunctions. Attached Figure Description

[0032] Figure 1 This is a structural block diagram of an IGBT module protection system for new energy commercial vehicles according to this utility model;

[0033] Figure 2 This utility model provides a structural block diagram of an IGBT module protection circuit for a new energy commercial vehicle.

[0034] Figure 3 This is a schematic diagram of the overall IGBT module protection system of this utility model;

[0035] Figure 4 This is the connection diagram of the PWM drive circuit of this utility model;

[0036] Figure 5 This is the logic diagram of the PWM drive signal of this utility model;

[0037] Figure 6 This is the PWM drive interlock logic diagram of this utility model;

[0038] Figure 7 This is the circuit diagram for the over / under voltage protection of the drive in this utility model;

[0039] Figure 8 This is the circuit diagram for desaturation detection of this utility model;

[0040] Figure 9 This is a schematic diagram of the equivalent thermal resistance model of this utility model;

[0041] Figure 10 This utility model is an IGBT module. Data table. Detailed Implementation

[0042] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0043] like Figures 1-10 As shown, the technical solution adopted by this utility model is as follows: A protection system for IGBT modules of new energy commercial vehicles, including: IGBT module, PWM drive interlock module, drive over / under voltage protection module, overcurrent protection module, short circuit protection module, and over-temperature / overload protection module.

[0044] like Figure 1 As shown, the first end of the PWM drive interlock module is connected to the second end of the over-temperature and overload protection module, the second end of the PWM drive interlock module is connected to the first end of the drive over-voltage and under-voltage protection module, the third end of the PWM drive interlock module is connected to the second end of the overcurrent protection module, the first end of the IGBT module is connected to the second end of the drive over-voltage and under-voltage protection module and the second end of the short-circuit protection module, the second end of the IGBT module is connected to the first end of the over-temperature and overload protection module, and the third end of the IGBT module is connected to the first end of the overcurrent protection module and the first end of the short-circuit protection module.

[0045] like Figure 2 As shown, the PWM drive interlock module is a DSP module, and the first end of the DSP module is connected to the second end of the IGBT drive module.

[0046] The drive over / under voltage protection module includes a drive over / under voltage protection circuit and an IGBT drive module, wherein the drive over / under voltage protection circuit is connected to the first terminal of the IGBT drive module.

[0047] The overcurrent protection module includes a Hall current sampling module and a hardware overcurrent comparison module.

[0048] The first end of the Hall current sampling module is connected to the third end of the IGBT module, the second end of the Hall current sampling module is connected to the second end of the hardware overcurrent comparison module, and one end of the hardware overcurrent comparison module is connected to the second end of the DSP module.

[0049] The short-circuit protection module includes a short-circuit circuit. The first end of the short-circuit circuit is connected to the first end of the IGBT module and the third end of the IGBT drive module. The second end of the short-circuit circuit is connected to the third end of the IGBT module and the first end of the Hall current sampling module.

[0050] The over-temperature and overload protection module includes an IGBT temperature sampling module, which includes a thermistor NTC. The first terminal of the IGBT temperature sampling module is connected to the second terminal of the IGBT module, and the second terminal of the IGBT temperature sampling module is connected to the third terminal of the DSP module.

[0051] like Figure 4 As shown, the microcontroller in the DSP module includes a PWM output port and The output port of the IGBT driver module includes a first driver and a second driver. Both the first driver and the second driver include an IP port, an IN port, and an output port.

[0052] The PWM output port is connected to the IP port of the first driver and the IN port of the second driver. The output port is connected to the IN port of the first driver and the IP port of the second driver.

[0053] like Figure 5 As shown, PWM is a pair of complementary signals with dead time, used as the upper and lower bridge inputs of the IGBT driver module. HS and T IS This is for the upper and lower bridge outputs of the IGBT driver module.

[0054] PWM interlock function such as Figure 6 As shown, when When PWM is disturbed, the following will occur: When T is high at the same time as PWM, HS and T IS It will then enter interlock mode, T HS and T IS The drive level is all switched to low, meaning that neither the upper nor lower bridge of the IGBT module is conducting, to prevent short circuits between bridge arms.

[0055] like Figure 7 As shown, the drive over / under voltage protection circuit includes diodes D2, D3, and D4, resistors R1, R2, and R3, transistors Q2 and Q3, a first comparator AMP1, a second comparator COMP1, a third comparator COMP2, a Vref1 port, and a Vref2 port.

[0056] The non-inverting input of the first comparator AMP1 is connected to the collector of transistor Q2 and the cathode of diode D4. The base of transistor Q2 is connected to the base of transistor Q3. The emitter of transistor Q2 is connected to the collector of transistor Q3 and one end of resistor R1. The other end of resistor R1 is connected to the anode of diode D4, the cathode of diode D2, and the IGBT driver module. The anode of diode D2 is connected to the anode of diode D3. The cathode of diode D3 is connected to the inverting input of the first comparator AMP1, the emitter of transistor Q3, and the IGBT module pin U_L_E. One end of resistor R2 is connected to the 5V power supply and resistor R3. The other end of resistor R2 is connected to the TZ3 pin of the DSP module and the output of the third comparator COMP2. The other end of resistor R3 is connected to the TZ4 pin of the DSP module and the output of the second comparator COMP1. The inverting input of the second comparator COMP1 is connected to the Vref1 port. The non-inverting input of the second comparator COMP1 is connected to the output of the first comparator AMP1 and the inverting input of the third comparator COMP2. The non-inverting input of the third comparator COMP2 is connected to the Vref2 port.

[0057] Figure 7 Transistor Q1 in the diagram is an IGBT module. Pin U_L_G of transistor Q1 is the IGBT driver module, driving over / under voltage protection by maintaining the voltage at pin U_L_G between +20V and -20V. The active clamping device for over / under voltage protection is a bidirectional TVS converter composed of diodes D2 and D3, with clamping voltages of 17.8V~20.5V and -17.8V~20.5V. Simultaneously, diode D4 can clamp the voltage to the UL+ port. The passive detection system consists of a first comparator AMP1, a second comparator COMP1, and a third comparator COMP2. The drive power supply for the IGBT module pins U_L_G is the voltage at the UL+ and UL- ports. The operational amplifier detects the power supply voltage. When the input voltage UL+ is lower than the reference voltage Vref1, the second comparator COMP1 reverses; when the input voltage UL- is higher than the reference voltage Vref2, the third comparator COMP2 reverses. The second and third comparators COMP1 and COMP2 are push-pull outputs. The UVLO port is connected to the TZ4 pin of the DSP module to transmit a drive undervoltage lockout fault signal, and the OVLO port is connected to the TZ3 pin of the DSP module to transmit a drive overvoltage lockout fault signal. When the DSP module receives or transmits a drive undervoltage lockout fault signal, it immediately shuts down the drive PWM signal. And to prevent damage to the module by preventing overvoltage lockout faults in the upload driver.

[0058] like Figure 3As shown, the hardware overcurrent comparison module includes a fourth comparator COMP3 and a Vref port.

[0059] The second terminal of the Hall current sampling module is connected to the inverting input terminal of the fourth comparator COMP3, the non-inverting input terminal of the fourth comparator COMP3 is connected to the Vref port, and the output terminal of the fourth comparator COMP3 is connected to the TZ6 pin of the DSP module.

[0060] The IGBT module's output current is converted into a voltage signal by a Hall current sampling module. This voltage signal is compared with the reference voltage Vref of the fourth comparator COMP3. If the voltage exceeds the reference voltage Vref threshold, the fourth comparator COMP3 reverses, the DSP module reports a hardware overcurrent fault, and simultaneously disables the drive PWM and... .

[0061] The DSP module determines the output current by acquiring the voltage signal from the Hall current sensor. A safe current threshold is preset within the DSP module. Through program checks, if the acquired current exceeds the preset threshold, the PWM driver is shut down. The signal simultaneously transmits both software and hardware overcurrent faults.

[0062] The DSP module pre-sets a safe current threshold as a supplement to the hardware overcurrent comparison protection module in case of failure. Hardware overcurrent faults are directly shut down by the trip signal output from pin TZ6 of the DSP module, which drives the PWM and... It is faster than program judgment and execution in terms of time.

[0063] The hardware overcurrent comparison protection module detects the overcurrent signal as a spike. After the current acquisition in the overcurrent signal is filtered, the DSP module is more sluggish in its response to the spike overcurrent signal. When the hardware overcurrent protection fails, the DSP module will provide protection by setting a safe current threshold in advance.

[0064] like Figure 8 As shown, the short-circuit protection circuit includes: resistor R4, diode D1, diode D5, transistor Q4, capacitor C1, Vref3 port, fifth comparator COMP4, VCE desaturation port, and TIs port.

[0065] The UL+ port is connected to the non-inverting input of the fifth comparator COMP4, the drain of transistor Q4, the input of capacitor C1, and the input of resistor R4. The inverting input of the fifth comparator COMP4 is connected to the Vref3 port. The output of the fifth comparator COMP4 is connected to the VCE desaturation port. The gate of transistor Q4 is connected to the cathode of diode D5. The TIs port is connected to the anode of diode D5 and the IGBT driver module. The source of transistor Q4 is connected to the output of capacitor C1 and the U_L_E pin of the IGBT module. The output of resistor R1 is connected to the anode of diode D1. The cathode of diode D1 is connected to the U_L_C pin of the IGBT module.

[0066] Figure 8 In this diagram, transistor Q1 represents the IGBT module, and pin U_L_G of transistor Q1 represents the IGBT driver module. When a short circuit occurs in the IGBT module, the current in the IGBT module rises sharply, reaching five times the rated current. The current then stops increasing, and the voltage across the IGBT module rises to the bus voltage. At this point, the IGBT module enters desaturation. By detecting the voltage across the IGBT module while it is conducting, it is possible to determine whether a short circuit has occurred.

[0067] When the TIs port voltage is high, the IGBT module is turned on, transistor Q4 is turned on, and the current from the UL+ port charges capacitor C1 at a voltage of Vdesat. Vdesat = Idesat * R1 + VF + Vce, where Idesat is the current supplied by the UL+ port, VF is the voltage drop across transistor D1, and Vce is the voltage across the IGBT module.

[0068] When a short circuit occurs, the voltage across the IGBT module rises, and the voltage at the non-inverting input of the fifth comparator COMP4 also rises. When the voltage at the non-inverting input of the fifth comparator COMP4 exceeds the reference voltage Vref3, the fifth comparator COMP4 is triggered, outputting a Vce desaturation signal. Upon detecting the Vce desaturation signal, the DSP module will shut down the drive PWM and... The signal is transmitted simultaneously to detect short-circuit faults, preventing continuous short circuits from damaging the IGBT module.

[0069] like Figure 3 As shown, the IGBT temperature sampling module is connected to the thermistor NTC.

[0070] The IGBT temperature sampling module converts the resistance change of the thermistor (NTC) into a voltage signal, acquires the temperature of the IGBT module through the DSP module, and estimates the temperature of the IGBT module chip and diodes using a thermal impedance model. Figure 9 As shown, the formula for calculating the junction temperature in the thermal impedance model is: ,in This represents the total loss of the IGBT module. TC represents the thermal resistance from junction temperature to case temperature. When the estimated junction temperature exceeds the junction derating value of the IGBT module, an over-temperature fault will be triggered, limiting power or shutting down the system.

[0071] IGBT module overload protection serves as a supplement to over-temperature protection. Junction temperature estimation requires the case temperature as a calculated value and is performed using a thermal resistance model. The case temperature sampling time is affected by filtering parameters and exhibits a certain delay. For example... Figure 10 As shown, based on the junction temperature estimation curve, a power-time inverse curve is plotted. The junction temperature calculated from the power at each point on the inverse curve is less than the junction temperature derating value. Software-limited IGBT power further protects the IGBT module, ensuring the operating junction temperature remains below the maximum junction temperature derating value.

[0072] The IGBT module protection system uses software to detect the current and temperature of the IGBT module for overcurrent, overload, and overtemperature protection, addressing damage caused by prolonged heat accumulation. Hardware integration includes PWM interlocking, VGE over / under voltage detection, output overcurrent detection, and VCE desaturation detection to handle damage caused by excessive instantaneous power loss. By incorporating IGBT module protection as a system solution, it identifies and protects against various abnormal operating conditions, significantly reducing the risk of damage even when the IGBT module malfunctions.

[0073] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A protection system for IGBT modules in new energy commercial vehicles, characterized in that, It includes: PWM drive interlock module, drive over / under voltage protection module, overcurrent protection module, short circuit protection module, and over-temperature / overload protection module; The first end of the PWM drive interlock module is connected to the second end of the over-temperature and overload protection module, the second end of the PWM drive interlock module is connected to the first end of the drive over-voltage and under-voltage protection module, the third end of the PWM drive interlock module is connected to the second end of the overcurrent protection module, the first end of the IGBT module is connected to the second end of the drive over-voltage and under-voltage protection module and the second end of the short-circuit protection module, the second end of the IGBT module is connected to the first end of the over-temperature and overload protection module, and the third end of the IGBT module is connected to the first end of the overcurrent protection module and the first end of the short-circuit protection module.

2. The IGBT module protection system for new energy commercial vehicles according to claim 1, characterized in that, The drive over / under voltage protection module includes a drive over / under voltage protection circuit and an IGBT drive module, wherein the drive over / under voltage protection circuit is connected to the first terminal of the IGBT drive module; The PWM drive interlock module includes a DSP module, the first end of which is connected to the second end of the IGBT drive module; The overcurrent protection module includes a Hall current sampling module and a hardware overcurrent comparison module; The first terminal of the Hall current sampling module is connected to the third terminal of the IGBT module, the second terminal of the Hall current sampling module is connected to the second terminal of the hardware overcurrent comparison module, and the first terminal of the hardware overcurrent comparison module is connected to the second terminal of the DSP module. The short-circuit protection module includes a short-circuit circuit. The first terminal of the short-circuit circuit is connected to the first terminal of the IGBT module and the third terminal of the IGBT drive module. The second terminal of the short-circuit circuit is connected to the third terminal of the IGBT module and the first terminal of the Hall current sampling module. The over-temperature and overload protection module includes an IGBT temperature sampling module. The first end of the IGBT temperature sampling module is connected to the second end of the IGBT module, and the second end of the IGBT temperature sampling module is connected to the third end of the DSP module.

3. The IGBT module protection system for new energy commercial vehicles according to claim 1, characterized in that, The IGBT module is equipped with a thermistor NTC.

4. The IGBT module protection system for new energy commercial vehicles according to claim 2, characterized in that, The DSP module includes a PWM output port and The IGBT driver module includes a first driver and a second driver. Each driver has an IP port, an IN port, and an output port. The PWM output port is connected to the IP port of the first driver and the IN port of the second driver. The output port is connected to the IN port of the first driver and the IP port of the second driver; The PWM output port outputs a PWM signal. Output port output Signals, PWM signals and The signals are a pair of complementary signals with dead time. When the PWM signal and When the signal is interfered with, a PWM signal appears and When both signals are at a high level, the outputs of the upper and lower bridge arms of the IGBT module enter an interlocked mode.

5. The IGBT module protection system for new energy commercial vehicles according to claim 4, characterized in that, The hardware overcurrent comparison module includes a fourth comparator COMP3 and a Vref port; The second terminal of the Hall current sampling module is connected to the inverting input terminal of the fourth comparator COMP3, the non-inverting input terminal of the fourth comparator COMP3 is connected to the Vref port, and the output terminal of the fourth comparator COMP3 is connected to the TZ6 pin of the DSP module. The IGBT module's output current is converted into a voltage signal by a Hall current sampling module. This voltage signal is compared to the reference voltage Vref of the fourth comparator COMP3. If the voltage exceeds the reference voltage Vref threshold, the fourth comparator COMP3 reverses, the DSP module reports a hardware overcurrent fault, and simultaneously disables the drive PWM signal. Signal; The DSP module pre-sets a safe current threshold as a supplement to the hardware overcurrent comparison protection module in case of failure. The hardware overcurrent comparison protection module detects overcurrent signals as spikes. After the current acquisition in the overcurrent signal is filtered, the DSP module is more sluggish in its response to spike overcurrent signals. When the hardware overcurrent protection fails, protection is provided by pre-setting a safe current threshold in the DSP module.

6. The IGBT module protection system for new energy commercial vehicles according to claim 2, characterized in that, The drive overvoltage and undervoltage protection circuit includes diodes D2, D3, and D4, resistors R1, R2, and R3, transistors Q2 and Q3, a first comparator AMP1, a second comparator COMP1, a third comparator COMP2, a Vref1 port, and a Vref2 port. The non-inverting input of the first comparator AMP1 is connected to the collector of transistor Q2 and the cathode of diode D4. The base of transistor Q2 is connected to the base of transistor Q3. The emitter of transistor Q2 is connected to the collector of transistor Q3 and one end of resistor R1. The other end of resistor R1 is connected to the anode of diode D4, the cathode of diode D2, and the IGBT driver module. The anode of diode D2 is connected to the anode of diode D3. The cathode of diode D3 is connected to the inverting input of the first comparator AMP1, the emitter of transistor Q3, and the IGBT module pin U_L_E. One end of resistor R2 is connected to the 5V power supply and resistor R3. The other end of resistor R2 is connected to the TZ3 pin of the DSP module and the output of the third comparator COMP2. The other end of resistor R3 is connected to the TZ4 pin of the DSP module and the output of the second comparator COMP1. The inverting input of the second comparator COMP1 is connected to the Vref1 port. The non-inverting input of the second comparator COMP1 is connected to the output of the first comparator AMP1 and the inverting input of the third comparator COMP2. The non-inverting input of the third comparator COMP2 is connected to the Vref2 port. When the collector voltage of transistor Q2 is lower than the reference voltage Vref1, the second comparator COMP1 will reverse; when the collector voltage of transistor Q2 is higher than the reference voltage Vref2, the third comparator COMP2 will reverse. Comparators COMP1 and COMP2 are push-pull outputs. The TZ4 pin of the DSP module transmits a drive undervoltage lockout fault signal, and the TZ3 pin transmits a drive overvoltage lockout fault signal. Upon receiving or transmitting a drive undervoltage lockout fault signal, the DSP module immediately shuts down the drive PWM signal. Signal, and upload driver undervoltage lockout fault.

7. A protection system for IGBT modules in new energy commercial vehicles according to claim 2, characterized in that, The short-circuit protection circuit includes: resistor R4, diode D1, diode D5, transistor Q4, capacitor C1, Vref3 port, fifth comparator COMP4, VCE desaturation port, and TIs port; The cathode of diode D4 is connected to the non-inverting input of the fifth comparator COMP4, the drain of transistor Q4, the input of capacitor C1, and the input of resistor R4. The inverting input of the fifth comparator COMP4 is connected to the Vref3 port. The output of the fifth comparator COMP4 is connected to the VCE desaturation port. The gate of transistor Q4 is connected to the cathode of diode D5. The TIs port is connected to the anode of diode D5 and the IGBT driver module. The source of transistor Q4 is connected to the output of capacitor C1 and the U_L_E pin of the IGBT module. The output of resistor R1 is connected to the anode of diode D1. The cathode of diode D1 is connected to the U_L_C pin of the IGBT module. When a short circuit occurs, the voltage across the IGBT module rises, and the voltage at the non-inverting input of the fifth comparator COMP4 also rises. When the voltage at the non-inverting input of the fifth comparator COMP4 exceeds the reference voltage Vref3, the fifth comparator COMP4 is triggered, outputting a Vce desaturation signal. Upon detecting the Vce desaturation signal, the DSP module will disable the drive PWM signal and... The signal simultaneously transmits a short-circuit fault.

8. The IGBT module protection system for new energy commercial vehicles according to claim 3, characterized in that, The IGBT temperature sampling module is connected to the thermistor NTC; The IGBT temperature sampling module converts the resistance change of the thermistor (NTC) into a voltage signal. The DSP module acquires the temperature of the IGBT module, and the junction temperature is estimated using a thermal impedance model to determine the temperature of the IGBT module chip and diodes. The formula for calculating the junction temperature using the thermal impedance model is as follows: ,in This represents the total loss of the IGBT module. The junction temperature is the thermal resistance from the junction temperature to the case temperature, and TC is the case temperature. When the estimated junction temperature exceeds the junction temperature derating value of the IGBT module, an over-temperature fault will be triggered, limiting power or shutting down the system.

Images