Temperature real-time acquisition circuit and over-temperature protection circuit of IGBT (Insulated Gate Bipolar Translator) of energy storage converter

Abstract

The utility model provides a temperature real-time acquisition circuit and an over-temperature protection circuit of an IGBT of an energy storage converter, and relates to the technical field of energy storage converters, a temperature sampling Wheatstone bridge circuit comprises a thermistor installed on the surface of a shell of a corresponding IGBT, and the thermistor is installed on the surface of the shell of the corresponding IGBT, so that the temperature of the IGBT can be acquired in real time. The influence of the radiator on the temperature of the IGBT is reduced, the temperature response speed is improved, the time delay of temperature monitoring is shortened, and the real-time performance of temperature monitoring is improved. By introducing the voltage-frequency conversion circuit and adopting a digital frequency signal mode to transmit IGBT real-time temperature signals, signal attenuation and signal interference in the analog signal transmission process are reduced, the accuracy of temperature monitoring is improved, and the temperature monitoring device is more stable and reliable. According to the temperature real-time acquisition circuit, each first diode is introduced, a first maximum voltage signal in six thermistors can be selected, analog-to-digital conversion resources of a processor are saved, and the processing efficiency of the processor is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of energy storage converters, in particular to a real-time temperature acquisition circuit and an over-temperature protection circuit of an IGBT of an energy storage converter. Background Art

[0002] In recent years, energy storage battery technology has continued to develop towards higher voltages and larger capacities, and the energy storage inverters that accompany these batteries have followed suit. However, these high voltages and large capacities pose significant challenges for energy storage inverters, as their components operate at high voltages and high currents. This leads to excessive voltage stress and energy loss, resulting in overheating of core components and potentially even thermal damage.

[0003] The core component of the energy storage converter is the bidirectional rectifier / inverter (DC / AC) module. The bidirectional DC / AC module is mainly based on the circuit topology of the insulated-gate bipolar transistor (IGBT).

[0004] IGBTs are often in rapid switching conditions. Furthermore, these high voltage and current conditions create very high IGBT temperatures. Severe overheating can lead to thermal damage, resulting in significant economic losses and safety hazards. Therefore, ensuring the safe operation of IGBTs has become a primary consideration for energy storage converter manufacturers.

[0005] At present, a thermistor is generally installed on the heat sink. The collected analog quantity is connected to the main control chip by connecting it in series with a known resistor for voltage division. The temperature of the thermistor is analyzed by the main control chip and this temperature is used as the temperature of the IGBT.

[0006] However, this implementation requires waiting for the IGBT temperature to be transmitted to the heat sink before the temperature can be collected through the thermistor, which will cause a time delay in the collected temperature and make it impossible to monitor the IGBT temperature in real time. Utility Model Content

[0007] The utility model provides a real-time temperature acquisition circuit and an over-temperature protection circuit of an IGBT of an energy storage converter, which are used to solve the defects existing in the related technology.

[0008] The utility model provides a real-time temperature acquisition circuit for an energy storage converter IGBT, comprising: a processor, a voltage-frequency conversion circuit for each phase, and a temperature sampling Wheatstone bridge circuit corresponding to each IGBT in each phase, a first operational amplifier circuit, and a first diode;

[0009] The temperature sampling Wheatstone bridge circuit includes a thermistor mounted on the surface of the housing of the corresponding IGBT;

[0010] The output end of the temperature sampling Wheatstone bridge circuit is connected to the input end of the first operational amplifier circuit, and the output end of the first operational amplifier circuit is connected to the anode of the first diode;

[0011] The processor is connected to the voltage-frequency conversion circuit, and the voltage-frequency conversion circuit is connected to the cathode of the first diode corresponding to each IGBT;

[0012] The voltage-frequency conversion circuit is configured to convert an input voltage signal into a digital frequency signal;

[0013] The processor is configured to determine a maximum digital frequency signal among the input digital frequency signals, and determine a maximum IGBT temperature of the energy storage converter according to the maximum digital frequency signal.

[0014] According to a temperature real-time acquisition circuit for an energy storage converter IGBT provided by the utility model, the temperature sampling Wheatstone bridge circuit further includes a driving power supply, a first bridge resistor, a second bridge resistor and a third bridge resistor;

[0015] The first operational amplifier circuit includes a first operational amplifier, a first non-phase terminal resistor, a second non-phase terminal resistor, a first inverting terminal resistor and a second inverting terminal resistor;

[0016] The driving power supply is grounded through the first bridge resistor and the second bridge resistor, and is grounded through the third bridge resistor and the thermistor;

[0017] A node between the first bridge resistor and the second bridge resistor is connected to the inverting input terminal of the first operational amplifier through the first inverting terminal resistor, and is connected to the output terminal of the first operational amplifier through the first inverting terminal resistor and the second inverting terminal resistor;

[0018] A node between the third bridge and the thermistor is connected to the non-inverting input terminal of the first operational amplifier through the first non-inverting terminal resistor, and is grounded through the first non-inverting terminal resistor and the second non-inverting terminal resistor.

[0019] According to a real-time temperature acquisition circuit for an energy storage converter IGBT provided by the utility model, the resistance values ​​of the first bridge resistor, the second bridge resistor, the third bridge resistor, the first positive phase terminal resistor, the second positive phase terminal resistor, the first negative phase terminal resistor and the second negative phase terminal resistor at the same point corresponding to each IGBT in each phase are respectively equal.

[0020] According to a temperature real-time acquisition circuit of an energy storage converter IGBT provided by the utility model, the voltage-frequency conversion circuit includes a voltage-to-frequency signal chip, a crystal oscillator, a first photoelectric coupler, a first pull-up resistor, a first current limiting resistor and a second pull-up resistor;

[0021] The signal input terminal of the voltage-to-frequency signal chip is connected to the output terminal of the voltage-to-frequency conversion circuit, the power supply terminal of the voltage-to-frequency signal chip is connected to the input terminal of the first photoelectric coupler via the first pull-up resistor and the first current-limiting resistor, and the frequency output terminal of the voltage-to-frequency signal chip is connected to the input terminal of the first photoelectric coupler via the first current-limiting resistor; the crystal oscillator is connected between the clock input terminal and the clock output terminal of the voltage-to-frequency signal chip;

[0022] The output end of the first photocoupler is connected to the processor and is connected to the first power supply through the second pull-up resistor.

[0023] According to the utility model, a real-time temperature acquisition circuit for an energy storage converter IGBT further includes: a voltage drop compensation circuit connected between the voltage-frequency conversion circuit and the cathode of the first diode corresponding to each IGBT in the same phase.

[0024] According to a temperature real-time acquisition circuit for an energy storage converter IGBT provided by the present invention, the voltage drop compensation circuit includes a signal sampling circuit and a second operational amplifier circuit connected in sequence, the signal sampling circuit includes a sampling power supply, a first sampling resistor, a second sampling resistor and a third sampling resistor, and the second operational amplifier circuit includes a second operational amplifier, a third inverting terminal resistor, a fourth inverting terminal resistor and a fifth inverting terminal resistor;

[0025] A first end of the first sampling resistor is connected to the cathode of the first diode corresponding to each IGBT, a second end of the first sampling resistor is connected to the non-inverting input terminal of the second operational amplifier and is grounded through the second sampling resistor, and the sampling power supply is grounded through the third sampling resistor and the second sampling resistor;

[0026] The first end of the third inverting terminal resistor and the first end of the fifth inverting terminal resistor are both grounded, the second end of the third inverting terminal resistor and the second end of the fifth inverting terminal resistor are both connected to the inverting input terminal of the second operational amplifier, and the inverting input terminal of the second operational amplifier is connected to the output terminal of the second operational amplifier through the fourth inverting terminal resistor;

[0027] The output end of the second operational amplifier is connected to the voltage-frequency conversion circuit.

[0028] According to a real-time temperature acquisition circuit for an energy storage converter IGBT provided by the present invention, the resistance values ​​of the first sampling resistor and the third inverting terminal resistor are equal, the resistance values ​​of the second sampling resistor and the fourth inverting terminal resistor are equal, and the resistance values ​​of the third sampling resistor and the fifth inverting terminal resistor are equal.

[0029] The utility model also provides an over-temperature protection circuit implemented based on the above-mentioned real-time temperature acquisition circuit of the energy storage converter IGBT, comprising: a third pull-up resistor, a comparator, a second photocoupler, or a logic operation chip, a plurality of second diodes, and a plurality of level conversion chips;

[0030] The anode of each second diode is connected to the output terminal of the voltage drop compensation circuit of one phase in a one-to-one correspondence, the cathode of each second diode is connected to the first input terminal of the comparator, and the second input terminal of the comparator is connected to the second power supply;

[0031] The output end of the comparator is connected to the input end of the second photoelectric coupler, and is connected to the driving power supply through the third pull-up resistor;

[0032] The output end of the second photoelectric coupler is connected to the first input end of the OR logic operation chip, the second input end of the OR logic operation chip is connected to the signal output end of the processor, the output end of the OR logic operation chip is connected to the enable end of each level conversion chip, the signal input end of each level conversion chip is used to receive the drive signal of the gate of each IGBT in one phase, and the signal output end of each level conversion chip is respectively connected to the gate of each IGBT in one phase;

[0033] The comparator is configured to compare the voltage signal inputted at the first input terminal with the second power supply voltage inputted at the second input terminal, and output a low level through the output terminal when the voltage signal inputted at the first input terminal is higher than or equal to the second power supply voltage;

[0034] The processor is configured to compare the maximum digital frequency signal with an over-temperature protection threshold frequency, and output a high level through the signal output terminal when the maximum digital frequency signal is higher than or equal to the over-temperature protection threshold frequency.

[0035] According to the utility model, an over-temperature protection circuit of an energy storage converter IGBT further includes: a PWM drive conditioning circuit;

[0036] The signal output end of each level conversion chip is connected to the gate of each IGBT in one phase through the PWM drive conditioning circuit.

[0037] According to the over-temperature protection circuit of the energy storage converter IGBT provided by the utility model, it also includes a fourth pull-up resistor, a fifth pull-up resistor and a second current limiting resistor;

[0038] The second input terminal of the OR logic operation chip is connected to the third power supply through the fourth pull-up resistor;

[0039] The output end of the second photocoupler is connected to the third power supply through the fifth pull-up resistor.

[0040] The utility model provides a real-time temperature acquisition circuit and over-temperature protection circuit for an energy storage converter IGBT. The temperature sampling Wheatstone bridge circuit includes a thermistor mounted on the surface of the corresponding IGBT housing. By mounting the thermistor on the surface of the corresponding IGBT housing, not only can the influence of the heat sink on the temperature of the IGBT be reduced, but the temperature response speed can also be increased, the time delay of temperature monitoring can be shortened, and the real-time performance of temperature monitoring can be improved. By introducing a voltage-frequency conversion circuit and using a digital frequency signal to transmit the real-time temperature signal of the IGBT, the signal attenuation and signal interference during the analog signal transmission process can be reduced, the accuracy of temperature monitoring can be improved, and the temperature monitoring can be more stable and reliable. Moreover, the real-time temperature acquisition circuit introduces each first diode to select the first maximum voltage signal from the six thermistors, saving the processor's analog-to-digital conversion resources and improving the processor's processing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the present invention or related technologies, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0042] Figure 1 The utility model provides a schematic diagram of the structure of a real-time temperature acquisition circuit for an energy storage converter IGBT.

[0043] Figure 2 This is a schematic diagram of the installation position of the thermistor provided by the utility model in the energy storage converter.

[0044] Figure 3 The utility model provides a bidirectional DC / AC circuit topology and a schematic diagram of the installation positions of the thermistors.

[0045] Figure 4 It is a structural schematic diagram of a temperature sampling Wheatstone bridge circuit provided by the utility model.

[0046] Figure 5It is a structural diagram of the voltage-frequency conversion circuit provided by the utility model.

[0047] Figure 6 It is a structural diagram of the voltage drop compensation circuit provided by the utility model.

[0048] Figure 7 The utility model is a schematic structural diagram of an over-temperature protection circuit of an IGBT of an energy storage converter.

[0049] Figure 8 It is a structural diagram of the electronic equipment provided by the utility model. DETAILED DESCRIPTION

[0050] To make the purpose, technical solutions, and advantages of the present invention more clear, the following will be combined with the accompanying drawings to clearly and completely describe the technical solutions of the present invention. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0051] Because existing IGBT temperature acquisition methods require waiting for the IGBT temperature to be transmitted to the heat sink before the temperature can be acquired through the thermistor, there is a time delay in the acquired temperature and the inability to monitor it in real time. Therefore, the present invention provides a real-time temperature acquisition circuit for an energy storage converter IGBT.

[0052] The real-time temperature acquisition circuit for the IGBT of the energy storage converter provided in the embodiment of the present invention (hereinafter referred to as the real-time temperature acquisition circuit) includes: a processor, a voltage-frequency conversion circuit for each phase, and a temperature sampling Wheatstone bridge circuit corresponding to each IGBT in each phase, a first operational amplifier circuit, and a first diode;

[0053] The temperature sampling Wheatstone bridge circuit includes a thermistor mounted on the surface of the housing of the corresponding IGBT;

[0054] The output end of the temperature sampling Wheatstone bridge circuit is connected to the input end of the first operational amplifier circuit, and the output end of the first operational amplifier circuit is connected to the anode of the first diode;

[0055] The processor is connected to the voltage-frequency conversion circuit, and the voltage-frequency conversion circuit is connected to the cathode of the first diode corresponding to each IGBT;

[0056] The voltage-frequency conversion circuit is configured to convert an input voltage signal into a digital frequency signal;

[0057] The processor is configured to determine a maximum IGBT temperature of the energy storage converter based on an input digital frequency signal.

[0058] Specifically, if Figure 1 As shown, the energy storage converter can include phases A, B, and C. Each phase includes six IGBTs, forming an IGBT module. The energy storage converter includes three IGBT modules, for a total of 18 IGBTs. Each phase in the real-time temperature acquisition circuit shares a processor U12, which can be a digital signal processor (DSP).

[0059] Each phase corresponds to a voltage-frequency conversion circuit 14 , and each IGBT in each phase corresponds to a temperature sampling Wheatstone bridge circuit 11 , a first operational amplifier circuit 12 and a first diode 13 .

[0060] Each temperature sampling Wheatstone bridge circuit 11 includes a thermistor mounted on the shell surface of the corresponding IGBT, and the temperature of the shell surface of the corresponding IGBT, that is, the temperature of the IGBT, is collected through the thermistor. The temperature of the IGBT can be represented by the voltage of the thermistor.

[0061] Figure 2 This is a schematic diagram of the installation position of the thermistor in the energy storage converter. The heat sink 1-1 in the energy storage converter is bonded to the IGBT 1-2. The thermistor 1-3 is installed on the shell surface of the IGBT and is connected to the real-time temperature acquisition circuit integrated in the circuit board device 1-4.

[0062] In the embodiment of the present invention, the thermistors used are all positive temperature coefficient thermistors, which have the characteristic that the higher the temperature, the greater the resistance value, and the greater the voltage obtained by series voltage division.

[0063] Therefore, the real-time temperature acquisition circuit may include 18 temperature sampling Wheatstone bridge circuits 11, 18 first operational amplifier circuits 12 and 18 first diodes 13, including 18 thermistors, which are respectively installed on the housing surface of an IGBT.

[0064] Compared with installing the thermistor on the radiator, it can not only reduce the impact of the radiator on the temperature of the IGBT, but also shorten the delay of temperature monitoring and improve the real-time performance of temperature monitoring.

[0065] Figure 3 The diagram below shows the bidirectional DC / AC circuit topology and the installation locations of the thermistors. Figure 3As shown, the bidirectional DC / AC circuit topology includes an energy storage battery BAT, a positive capacitor C1, a negative capacitor C2, a positive bus sampling voltmeter U1, a negative bus sampling voltmeter U2, an A-phase two-phase DC / AC circuit, a B-phase two-phase DC / AC circuit, and a C-phase two-phase DC / AC circuit, and also includes an AC LC filter circuit and an AC power grid connected to the A-phase two-phase DC / AC circuit, the B-phase two-phase DC / AC circuit, and the C-phase two-phase DC / AC circuit.

[0066] The A-phase dual-phase DC / AC circuit includes six IGBTs, namely IGBT1-IGBT6, the gate drive signals of the six IGBTs are respectively T1A-T6A, and the thermistors mounted on the housing surfaces of the six IGBTs are respectively Rc1-Rc6.

[0067] The B-phase two-phase DC / AC circuit includes six IGBTs, namely IGBT7-IGBT12, the gate drive signals of the six IGBTs are respectively T1B-T6B, and the thermistors mounted on the housing surfaces of the six IGBTs are respectively Rc7-Rc12.

[0068] The C-phase dual-phase DC / AC circuit includes six IGBTs, namely IGBT13-IGBT18, the gate drive signals of the six IGBTs are respectively T1C-T6C, and the thermistors mounted on the housing surfaces of the six IGBTs are respectively Rc13-Rc18.

[0069] For each IGBT, the output of the temperature-sampling Wheatstone bridge circuit 11 is connected to the input of a first operational amplifier circuit 12, and the output of the first operational amplifier circuit 12 is connected to the anode of a first diode 13. The first operational amplifier circuit 12 can be a differential operational amplifier circuit. The temperature-sampling Wheatstone bridge circuit 11 can determine the voltage across the thermistor, representing the temperature of the corresponding IGBT, and input the voltage as a differential signal to the first operational amplifier circuit 12 for amplification.

[0070] The voltage of the thermistor is amplified by the first operational amplifier circuit 12 and then output to the voltage-frequency conversion circuit 14 via the first diode 13 .

[0071] Since each IGBT in the same phase corresponds to a corresponding first diode 13, and the cathodes of all six first diodes 13 are connected to the voltage-frequency conversion circuit 14, the circuits corresponding to each IGBT are connected in parallel. Due to the unidirectional conductivity of the six first diodes 13, only one first diode 13 with the maximum voltage signal can conduct to the voltage-frequency conversion circuit 14, transmitting the maximum voltage signal among the six thermistors (labeled as the first maximum voltage signal) to the voltage-frequency conversion circuit 14. The first maximum voltage signal is the voltage of the thermistor mounted on the housing surface of the IGBT with the highest temperature. Thus, the six parallel first diodes 13 form a first maximum voltage signal selection circuit. Selecting the first maximum voltage signal conserves processor analog-to-digital converter (ADC) resources and simplifies the processor's software algorithm, which can be implemented using conventional software algorithms, thereby improving processor processing efficiency.

[0072] The voltage-frequency conversion circuit can convert the input voltage signal into a digital frequency signal. Since the first maximum voltage signal selected and output by the six first diodes 13 is a voltage analog signal, signal attenuation and signal interference may occur during its transmission. Therefore, by inputting the first maximum voltage signal into the voltage-frequency conversion circuit, the voltage analog signal is converted into a digital frequency signal, and the digital frequency signal is transmitted to the processor U12 in real time, which can reduce signal attenuation and signal interference during the analog signal transmission process.

[0073] The processor U12 can be connected to each voltage-frequency conversion circuit 14 and can determine the maximum digital frequency signal among the digital frequency signals output by each voltage-frequency conversion circuit 14 through comparison. The processor U12 can have a built-in correspondence between digital frequency signals and IGBT temperatures. By substituting the maximum digital frequency signal into this correspondence, the IGBT temperature can be obtained. This IGBT temperature is the maximum IGBT temperature, thereby achieving real-time temperature acquisition of the energy storage converter IGBT.

[0074] The present invention provides a real-time temperature acquisition circuit for an energy storage converter IGBT, comprising a processor, a voltage-frequency conversion circuit for each phase, a temperature sampling Wheatstone bridge circuit corresponding to each IGBT in each phase, a first operational amplifier circuit, and a first diode. The temperature sampling Wheatstone bridge circuit includes a thermistor mounted on the surface of the corresponding IGBT housing. Mounting the thermistor on the surface of the corresponding IGBT housing not only reduces the impact of the heat sink on the IGBT temperature but also improves temperature response speed, shortens temperature monitoring delay, and enhances the real-time performance of temperature monitoring. By introducing a voltage-frequency conversion circuit and transmitting the IGBT's real-time temperature signal as a digital frequency signal, the circuit reduces signal attenuation and interference during analog signal transmission, improves temperature monitoring accuracy, and enhances stability and reliability. Furthermore, the real-time temperature acquisition circuit incorporates each first diode to select the first maximum voltage signal from the six thermistors, conserving the processor's analog-to-digital converter (ADC) resources and improving processor processing efficiency.

[0075] On the basis of the above embodiment, the temperature sampling Wheatstone bridge circuit further includes a driving power supply, a first bridge resistor, a second bridge resistor and a third bridge resistor;

[0076] The first operational amplifier circuit includes a first operational amplifier, a first non-phase terminal resistor, a second non-phase terminal resistor, a first inverting terminal resistor and a second inverting terminal resistor;

[0077] The driving power supply is grounded through the first bridge resistor and the second bridge resistor, and is grounded through the third bridge resistor and the thermistor;

[0078] A node between the first bridge resistor and the second bridge resistor is connected to the inverting input terminal of the first operational amplifier through the first inverting terminal resistor, and is connected to the output terminal of the first operational amplifier through the first inverting terminal resistor and the second inverting terminal resistor;

[0079] A node between the third bridge and the thermistor is connected to the non-inverting input terminal of the first operational amplifier through the first non-inverting terminal resistor, and is grounded through the first non-inverting terminal resistor and the second non-inverting terminal resistor.

[0080] Specifically, each temperature sampling Wheatstone bridge circuit has the same structure, including a thermistor, a driving power supply VCC, a first bridge resistor, a second bridge resistor, and a third bridge resistor. The voltage signal of the driving power supply VCC can be 5V.

[0081] like Figure 4As shown, taking phase A as an example, the first bridge resistors in the temperature sampling Wheatstone bridge circuit corresponding to IGBT1-IGBT6 are R1, R8, R15, R22, R29 and R36 respectively, the second bridge resistors in the temperature sampling Wheatstone bridge circuit corresponding to IGBT1-IGBT6 are R2, R9, R16, R23, R30 and R37 respectively, and the third bridge resistors in the temperature sampling Wheatstone bridge circuit corresponding to IGBT1-IGBT6 are R3, R10, R17, R24, R31 and R38 respectively.

[0082] The resistance values ​​of the first bridge resistor and the third bridge resistor in the temperature sampling Wheatstone bridge circuit corresponding to each IGBT are equal, and the resistance value of the second bridge resistor is the resistance value of the thermistor when the IGBT temperature is lowest.

[0083] Each first operational amplifier circuit has the same structure, including a first operational amplifier, a first non-phase terminal resistor, a second non-phase terminal resistor, a first inverting terminal resistor, and a second inverting terminal resistor. Figure 4 As shown, the first operational amplifiers in the first operational amplifier circuit corresponding to IGBT1-IGBT6 are U1-U6 respectively, the first non-phase terminal resistors in the first operational amplifier circuit corresponding to IGBT1-IGBT6 are R4, R11, R18, R25, R32 and R39 respectively, the second non-phase terminal resistors in the first operational amplifier circuit corresponding to IGBT1-IGBT6 are R5, R12, R19, R26, R33 and R40 respectively, the first inverting terminal resistors in the first operational amplifier circuit corresponding to IGBT1-IGBT6 are R6, R13, R20, R27, R34 and R41 respectively, and the second inverting terminal resistors in the first operational amplifier circuit corresponding to IGBT1-IGBT6 are R7, R14, R21, R28, R35 and R42 respectively.

[0084] In each temperature-sampling Wheatstone bridge circuit, the driving power supply VCC is connected to ground via a first bridge resistor and a second bridge resistor, and is also connected to ground via a third bridge resistor and a thermistor. The node between the first bridge resistor and the second bridge resistor serves as one output terminal of the temperature-sampling Wheatstone bridge circuit, connected to the inverting input terminal of the first operational amplifier via a first inverting terminal resistor, and connected to the output terminal of the first operational amplifier via the first inverting terminal resistor and the second inverting terminal resistor. The node between the third bridge resistor and the thermistor serves as another output terminal of the temperature-sampling Wheatstone bridge circuit, connected to the non-inverting input terminal of the first operational amplifier via the first inverting terminal resistor, and is grounded via the first inverting terminal resistor and the second inverting terminal resistor.

[0085] Both output terminals of each temperature sampling Wheatstone bridge circuit can output differential signals. The voltage signal at the node between the first bridge resistor and the second bridge resistor is Va, and the voltage signal at the node between the third bridge resistor and the thermistor is Vb.

[0086] like Figure 4 As shown, the voltage signals outputted by the output terminals of the first operational amplifiers in the first operational amplifier circuits corresponding to IGBT1 - IGBT6 are V1 - V6 respectively.

[0087] The output ends of the first operational amplifiers in the first operational amplifier circuits corresponding to IGBT1 - IGBT6 are all connected to a first diode, D1 - D6 respectively, and ultimately output a first maximum voltage signal V7 .

[0088] Based on the above embodiment, the resistance values ​​of the first bridge resistor, the second bridge resistor, the third bridge resistor, the first positive phase terminal resistor, the second positive phase terminal resistor, the first negative phase terminal resistor and the second negative phase terminal resistor at the same point corresponding to each IGBT in each phase are respectively equal.

[0089] Specifically, the resistance values ​​of R1, R8, R15, R22, R29, and R36 can be equal, for example, they can all be r101; the resistance values ​​of R2, R9, R16, R23, R30, and R37 can be equal, for example, they can all be r102; the resistance values ​​of R3, R10, R17, R24, R31, and R38 can be equal, for example, they can all be r103. When the resistance values ​​of the first bridge resistor and the third bridge resistor in the temperature sampling Wheatstone bridge circuit corresponding to each IGBT are equal, r101=r103.

[0090] Similarly, the resistance values ​​of R4, R11, R18, R25, R32 and R39 can be equal, for example, they can all be r104; the resistance values ​​of R5, R12, R19, R26, R33 and R40 can be equal, for example, they can all be r105; the resistance values ​​of R6, R13, R20, R27, R34 and R41 can be equal, for example, they can all be r106; the resistance values ​​of R7, R14, R21, R28, R35 and R42 can be equal, for example, they can all be r107.

[0091] Taking the temperature sampling Wheatstone bridge circuit corresponding to IGBT1 as an example, according to the virtual short, virtual open, and Kirchhoff circuit laws of the operational amplifier, the relationship between V1 and the resistance value rc1 of Rc1 is calculated as follows:

[0092] ;

[0093] ;

[0094] ;

[0095] ;

[0096] According to the virtual short of the operational amplifier, we have:

[0097] ;

[0098] From the above formula we can get:

[0099] .

[0100] In this embodiment of the utility model, by setting the resistance values ​​of the resistors at the same points corresponding to each IGBT in each phase to be equal, the relationship between V1 and rc1 can be quickly determined, simplifying the relationship calculation process. Furthermore, the subsequent calculation process can be simplified, quickly determining the relationship between V7 and the resistance values ​​of each thermistor in phase A.

[0101] Since D1-D6 all have diode forward voltage drops, and the diode forward voltage drop is known to be 0.7V, V7 can be calculated using the following formula:

[0102] ;

[0103] ;

[0104] Where rc=max{rc1,...,rc6}, and rc1-rc6 are the resistance values ​​of Rc1-Rc6 respectively.

[0105] Based on the above embodiment, the real-time temperature acquisition circuit further includes: a voltage drop compensation circuit connected between the voltage-frequency conversion circuit and the cathode of the first diode corresponding to each IGBT in the same phase.

[0106] Specifically, the real-time temperature acquisition circuit includes three voltage drop compensation circuits, one for each phase. The cathode of the first diode corresponding to each IGBT in the same phase is connected to the input of the voltage drop compensation circuit, and the output of the voltage drop compensation circuit is connected to the voltage-frequency conversion circuit. This voltage drop compensation circuit compensates for inaccuracies in the voltage signal caused by the inherent characteristics of the first diode, further improving the accuracy of real-time IGBT temperature monitoring.

[0107] On the basis of the above embodiment, the voltage-frequency conversion circuit includes a voltage-to-frequency signal chip, a crystal oscillator, a first photocoupler, a first pull-up resistor, a first current-limiting resistor, and a second pull-up resistor;

[0108] The signal input terminal of the voltage-to-frequency signal chip is connected to the output terminal of the voltage-to-frequency conversion circuit, the power supply terminal of the voltage-to-frequency signal chip is connected to the input terminal of the first photoelectric coupler via the first pull-up resistor and the first current-limiting resistor, and the frequency output terminal of the voltage-to-frequency signal chip is connected to the input terminal of the first photoelectric coupler via the first current-limiting resistor; the crystal oscillator is connected between the clock input terminal and the clock output terminal of the voltage-to-frequency signal chip;

[0109] The output end of the first photocoupler is connected to the processor and is connected to the first power supply through the second pull-up resistor.

[0110] Specifically, taking phase A as an example, the input end of the voltage drop compensation circuit can be input with V7, the output end can be expressed as NET_A, and the compensated voltage signal V8 can be output.

[0111] like Figure 5 As shown, the voltage-frequency conversion circuit includes a voltage-to-frequency signal chip U10, a crystal oscillator Y1, a first photocoupler U11, a first pull-up resistor R50, a first current-limiting resistor R51 and a second pull-up resistor R52.

[0112] The signal input terminal VIN of the voltage-to-frequency signal chip U10 is connected to the output terminal NET_A of the voltage-to-frequency conversion circuit. The power supply terminal VDD of the voltage-to-frequency signal chip U10 is connected to the input terminal of the first optocoupler U11 through the first pull-up resistor R50 and the first current-limiting resistor R51. The power supply terminal VDD can be connected to the driving power supply VCC.

[0113] The frequency output terminal FOUT of the voltage-to-frequency signal chip U10 is connected to the input terminal of the first photocoupler U11 through a first current-limiting resistor R51. The output terminal of the first photocoupler U11 is connected to the processor U12 and to the first power supply through a second pull-up resistor R52. Here, the voltage of the first power supply can be 3.3V.

[0114] The first photocoupler U11 may include a light emitting diode and a phototransistor, the input end of the first photocoupler U11 may be the anode of the light emitting diode, the output end of the first photocoupler U11 may be the collector of the phototransistor, and the output end of the first photocoupler U11 may output a digital frequency signal Fout1.

[0115] The crystal oscillator Y1 is connected between the clock input terminal CLKIN and the clock output terminal CLKOUT of the voltage-to-frequency signal chip. The clock input terminal CLKIN can be grounded through a first capacitor C11, and the clock output terminal CLKOUT can be grounded through a second capacitor C12.

[0116] The corresponding relationship between the voltage signal input to the voltage-frequency conversion circuit and the digital frequency signal output can be expressed as:

[0117] ;

[0118] in, , The frequency of the clock signal input to the clock input terminal CLKIN.

[0119] In the embodiment of the present invention, the analog voltage signal is converted into a digital frequency signal through a crystal oscillator, the circuit structure is simple, and the construction cost is low.

[0120] Based on the above embodiments, Figure 6 As shown, taking phase A as an example, the voltage drop compensation circuit includes a signal sampling circuit and a second operational amplifier circuit connected in sequence. The signal sampling circuit includes a sampling power supply, a first sampling resistor R43, a second sampling resistor R44, and a third sampling resistor R45. The second operational amplifier circuit includes a second operational amplifier U7, a third inverting terminal resistor R46, a fourth inverting terminal resistor R47, and a fifth inverting terminal resistor R48. The sampling power supply voltage can be 2V.

[0121] The first end of the first sampling resistor R43 serves as the input of the voltage drop compensation circuit, is connected to the cathode of the first diode corresponding to each IGBT, and is connected to V7. The second end of the first sampling resistor R43 is connected to the non-inverting input terminal of the second operational amplifier U7 and is grounded through the second sampling resistor R44. The sampling power supply is grounded through the third sampling resistor R45 and the second sampling resistor R44.

[0122] The first end of the third inverting terminal resistor R46 and the first end of the fifth inverting terminal resistor R48 are both grounded, the second end of the third inverting terminal resistor R46 and the second end of the fifth inverting terminal resistor R48 are both connected to the inverting input terminal of the second operational amplifier U7, and the inverting input terminal of the second operational amplifier U7 is connected to the output terminal of the second operational amplifier U7 through the fourth inverting terminal resistor R47.

[0123] The output terminal NET_A of the second operational amplifier U7 is connected to the voltage-frequency conversion circuit and outputs V8 to the voltage-frequency conversion circuit.

[0124] Based on the above embodiment, the resistance values ​​of the first sampling resistor R43 and the third inverting terminal resistor R46 are equal, and can both be equal to r108; the resistance values ​​of the second sampling resistor R44 and the fourth inverting terminal resistor R47 are equal, and can both be equal to r109; and the resistance values ​​of the third sampling resistor R45 and the fifth inverting terminal resistor R48 are equal, and can both be equal to r110.

[0125] Specifically, the relationship between V8 and the resistance of each thermistor in phase A can be calculated based on the virtual short circuit, virtual open circuit, and Kirchhoff's circuit laws of the operational amplifier.

[0126] According to the virtual disconnection of the operational amplifier and Kirchhoff's circuit law, we have:

[0127] ;

[0128] ;

[0129] According to the virtual short of the operational amplifier, we have:

[0130] ;

[0131] From the above formula we can get:

[0132] .

[0133] In the embodiment of the present invention, the second sampling resistor R44 and the fourth inverting terminal resistor R47 can both be 7K resistors, the third sampling resistor R45 and the fifth inverting terminal resistor R48 can both be 20K resistors, and the first sampling resistor R43 and the third inverting terminal resistor R46 can both be 7K resistors.

[0134] From this we can conclude that:

[0135] .

[0136] In the embodiment of the present invention, by setting the resistance values ​​of the first sampling resistor and the third inverting terminal resistor to be equal, setting the resistance values ​​of the second sampling resistor and the fourth inverting terminal resistor to be equal, and setting the resistance values ​​of the third sampling resistor and the fifth inverting terminal resistor to be equal, the relationship between V8 and the resistance values ​​of each thermistor in phase A can be quickly determined.

[0137] In existing technologies, when an IGBT overheats, the drive signal to the IGBT can only be cut off through software algorithm control to prevent thermal damage to the IGBT. However, the software algorithm control process has a time delay, which greatly reduces its timeliness.

[0138] Based on this, on the basis of the above embodiment, as Figure 7As shown, the present invention also provides an over-temperature protection circuit based on the real-time temperature acquisition circuit of the energy storage converter IGBT in each of the above embodiments. The over-temperature protection circuit includes: a third pull-up resistor R61, a comparator U13, a second photocoupler U15, or a logic operation chip U16, multiple second diodes, and multiple level conversion chips. The second diodes are represented by D7-D9, and the level conversion chips are represented by U17-U19. The model of each level conversion chip can be SN74LVCC.

[0139] The truth table of each level conversion chip can be shown in Table 1:

[0140] Table 1 Truth table of the level conversion chip

[0141]

[0142] in, It is the enable terminal of the level conversion chip, L is low level and H is high level.

[0143] The anode of each second diode is connected to the output terminal of the voltage drop compensation circuit of one phase in a one-to-one correspondence. The output terminal NET_A of the voltage drop compensation circuit of phase A is connected to the anode of D7, the output terminal NET_B of the voltage drop compensation circuit of phase B is connected to the anode of D8, and the output terminal NET_C of the voltage drop compensation circuit of phase C is connected to the anode of D9.

[0144] The cathode of each second diode is connected to the first input of comparator U13. Due to the unidirectional conductivity of the three second diodes, only one second diode with the maximum voltage signal can conduct to the first input of comparator U13, transmitting the maximum voltage signal (labeled as the second maximum voltage signal V10) output by the output of the three-phase voltage drop compensation circuit to the first input of comparator U13. The second maximum voltage signal V10 is the voltage of the thermistor mounted on the housing surface of the IGBT with the highest temperature among the three phases. Thus, the three parallel second diodes form a second maximum voltage signal selection circuit.

[0145] The second input terminal of the comparator U13 is connected to a second power supply, and the second power supply voltage provided by the second power supply is the IGBT over-temperature protection threshold voltage Vth.

[0146] The comparator U13 can compare the voltage signal input to the first input terminal, i.e., the second maximum voltage signal, with the second power supply voltage input to the second input terminal, and output a low level through the output terminal when the voltage signal input to the first input terminal is higher than or equal to the second power supply voltage.

[0147] The output of the comparator U13 is connected to the input of the second photocoupler U15 and to the driving power supply VCC via the third pull-up resistor R61. The second photocoupler U15 converts the voltage of the driving power supply VCC into a 3.3V voltage.

[0148] The output end of the second photocoupler U15 is connected to the first input end B of the logic operation chip U16, or the second input end A of the logic operation chip U16 is connected to the signal output end GPIO1 of the processor U12, or the output end Y of the logic operation chip U16 is connected to the gate of each IGBT.

[0149] The processor U12 is configured to compare the maximum digital frequency signal Fout with the over-temperature protection threshold frequency Fth, and output a high level through the signal output terminal GPIO1 when the maximum digital frequency signal Fout is higher than or equal to the over-temperature protection threshold frequency Fth.

[0150] The implementation logic of the OR logic operation chip U16 is: if both the first input terminal B and the second input terminal A input a low level, the output terminal Y outputs a low level; otherwise, the output terminal Y outputs a high level.

[0151] The output terminal Y of the OR logic operation chip U16 and the enable terminal of each level conversion chip The signal input terminals of each level shifter chip are connected to the gate drive signals of each IGBT in a phase. That is, the signal input terminals B1-B6 of U17 are used to receive the gate drive signals of each IGBT in phase A, the signal input terminals B1-B6 of U18 are used to receive the gate drive signals of each IGBT in phase B, and the signal input terminals B1-B6 of U19 are used to receive the gate drive signals of each IGBT in phase C. The signal output terminals of each level shifter chip are respectively connected to the gates of each IGBT in a phase. That is, the signal output terminals A1-A6 of U17 are respectively connected to the gates of each IGBT in phase A, the signal output terminals A1-A6 of U18 are respectively connected to the gates of each IGBT in phase B, and the signal output terminals A1-A6 of U19 are respectively connected to the gates of each IGBT in phase C.

[0152] Therefore, at the software level of the processor U12, when Fout is greater than or equal to Fth, the processor U12 will output a high level, or the second input terminal A of the logic operation chip U16 is a high level, and the output terminal Y outputs a high level.

[0153] The output terminal Y of the logic operation chip U16 outputs a high level, which respectively turns on the enable terminals of U17-U19. Pulled to a high level, according to the truth table of the OR logic operation chip U16, the input and output are in an isolated state, that is, the drive signal transmission to the IGBT can be cut off in real time, and the IGBT stops working.

[0154] Based on the above embodiments, Figure 7 As shown, it also includes a fourth pull-up resistor R64, a fifth pull-up resistor and a second current limiting resistor;

[0155] The second input terminal A of the OR logic operation chip U16 is connected to the third power supply through the fourth pull-up resistor R64. Here, the voltage of the third power supply can be equal to the voltage of the first power supply, both of which are 3.3V.

[0156] The output end of the second photocoupler U15 is connected to the third power supply through the fifth pull-up resistor R63.

[0157] In addition, the output terminal of the comparator U13 may be connected to the input terminal of the second photocoupler U15 via the second current limiting resistor R62 .

[0158] The output terminal Y of the OR logic operation chip U16 is connected to the third power supply through the sixth pull-up resistor R65, so that the enable terminal of each level conversion chip is at a high level in the initial state.

[0159] A threshold resistor R60 is further connected between the second input terminal and the output terminal of the comparator U13.

[0160] thus, Figure 7 U12, R64 and U16 constitute the IGBT software over-temperature protection circuit.

[0161] Figure 7 The electronic components except U12, R64, and U16 2.3.1 constitute the IGBT hardware over-temperature protection circuit, and its working process is as follows:

[0162] D7-D9 are used to select the second maximum voltage signal V10 output from the output terminal of the voltage drop compensation circuit in phase A, phase B, and phase C. V10 is compared with Vth through U13. If V10 is greater than or equal to Vth, the output terminal of U13 outputs a low level, the input current of U15 is 0, and the output terminal of U15 is pulled up to VCC by the third pull-up resistor R61. The first input terminal B of U16 is high, and the output terminal Y of U16 outputs a high level. The output terminal Y of U16 outputs a high level, which will enable the enable terminals of U17-U19. When pulled to a high level, the input and output of U17-U19 are in an isolated state, that is, the transmission of the driving signal to the IGBT can be cut off in real time, and the IGBT stops working.

[0163] In the present embodiment, two types of IGBT overtemperature protection are implemented. Because IGBT software overtemperature protection requires processor mechanical energy processing and results in a significant delay, the IGBT hardware overtemperature protection circuit offers a very short delay, faster than software overtemperature protection. Combining the two, with hardware overtemperature protection as the primary and software protection as the supplementary, achieves dual overtemperature protection, accurately and promptly preventing IGBT thermal damage, reducing economic losses, and avoiding potential safety hazards, significantly improving the stability and safety of the IGBT.

[0164] Based on the above embodiments, Figure 7 As shown, the over-temperature protection circuit also includes a PWM drive conditioning circuit U20;

[0165] The signal output end of each level conversion chip is connected to the gate of each IGBT in one phase through the PWM drive conditioning circuit U20, that is, the signal output ends A1-A6 of U17 are respectively connected to the gate of each IGBT in phase A through the PWM drive conditioning circuit U20, the signal output ends A1-A6 of U18 are respectively connected to the gate of each IGBT in phase B through the PWM drive conditioning circuit U20, and the signal output ends A1-A6 of U19 are respectively connected to the gate of each IGBT in phase C through the PWM drive conditioning circuit U20.

[0166] Through the PWM drive conditioning circuit, the drive signal output from the output end of U17-U19 can be smoothly transmitted to each IGBT.

[0167] In summary, if Figure 8 The figure shows the working flow chart of the real-time temperature acquisition circuit and over-temperature protection circuit of the energy storage converter IGBT.

[0168] First, thermistors are installed on the surface of the IGBT housing to collect the temperature of the IGBT housing surface. There are 18 thermistors in total.

[0169] Then, the voltage signal of the thermistor mounted on the housing surface of each IGBT in the same phase is collected through 6 temperature sampling Wheatstone bridge circuits.

[0170] Thereafter, the voltage signal is amplified by the first operational amplifier circuit, and the first maximum voltage signal of each phase is selected through each first diode.

[0171] Thereafter, a voltage drop compensation circuit is used to perform voltage drop compensation on the first maximum voltage signal.

[0172] Afterward, the compensated voltage signal is converted into a digital frequency signal via a voltage-frequency conversion circuit. A second optocoupler is used to convert the drive power supply VCC to a third power supply level. The digital frequency signal of each phase is transmitted to the processor, which determines the maximum digital frequency signal among the three phases and calculates and displays the maximum IGBT temperature of the energy storage converter based on the maximum digital frequency signal. Furthermore, the maximum digital frequency signal Fout is compared with Fth. If Fout ≥ Fth, the processor's signal output terminal GPIO outputs a high level, or the second input terminal A of the logic operation chip U16 inputs a high level.

[0173] On the other hand, the second maximum voltage signal V10 is selected by each second diode, and then V10 is compared with Vth. If V10 ≥ Vth, the output end of the comparator U13 outputs a low level, the second photocoupler stops working, or the first input end B of the logic operation chip U16 inputs a high level.

[0174] After that, the output end of the OR logic operation chip U16 outputs a high level, the enable end of U17-U19 is a high level, the signal input end of U17-U19 stops transmitting data to the signal output end, and the IGBT stops working to protect the IGBT and avoid thermal damage to the IGBT.

[0175] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0176] Through the description of the above embodiments, those skilled in the art will clearly understand that each embodiment can be implemented using software plus a necessary general-purpose hardware platform, or of course, hardware. Based on this understanding, the essence of the above technical solution, or the portion that contributes to the relevant technology, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, or an optical disk, and includes a number of instructions for causing a computer device (such as a personal computer, server, or network device) to execute the methods described in each embodiment or certain portions of the embodiments.

[0177] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A real-time temperature acquisition circuit for an energy storage converter IGBT, characterized in that: include: A processor, a voltage-frequency conversion circuit for each phase, and a temperature sampling Wheatstone bridge circuit, a first operational amplifier circuit, and a first diode corresponding to each IGBT in each phase; The temperature sampling Wheatstone bridge circuit includes a thermistor mounted on the surface of the housing of the corresponding IGBT; The output end of the temperature sampling Wheatstone bridge circuit is connected to the input end of the first operational amplifier circuit, and the output end of the first operational amplifier circuit is connected to the anode of the first diode; The processor is connected to the voltage-frequency conversion circuit, and the voltage-frequency conversion circuit is connected to the cathode of the first diode corresponding to each IGBT; The voltage-frequency conversion circuit is configured to convert an input voltage signal into a digital frequency signal; The processor is configured to determine a maximum digital frequency signal among the input digital frequency signals, and determine a maximum IGBT temperature of the energy storage converter according to the maximum digital frequency signal.

2. The real-time temperature acquisition circuit of the energy storage converter IGBT according to claim 1, characterized in that: The temperature sampling Wheatstone bridge circuit further includes a driving power supply, a first bridge resistor, a second bridge resistor and a third bridge resistor; The first operational amplifier circuit includes a first operational amplifier, a first non-phase terminal resistor, a second non-phase terminal resistor, a first inverting terminal resistor and a second inverting terminal resistor; The driving power supply is grounded through the first bridge resistor and the second bridge resistor, and is grounded through the third bridge resistor and the thermistor; A node between the first bridge resistor and the second bridge resistor is connected to the inverting input terminal of the first operational amplifier through the first inverting terminal resistor, and is connected to the output terminal of the first operational amplifier through the first inverting terminal resistor and the second inverting terminal resistor; A node between the third bridge and the thermistor is connected to the non-inverting input terminal of the first operational amplifier through the first non-inverting terminal resistor, and is grounded through the first non-inverting terminal resistor and the second non-inverting terminal resistor.

3. The real-time temperature acquisition circuit of the energy storage converter IGBT according to claim 2, characterized in that: The resistance values ​​of the first bridge resistor, the second bridge resistor, the third bridge resistor, the first positive phase terminal resistor, the second positive phase terminal resistor, the first negative phase terminal resistor and the second negative phase terminal resistor at the same points corresponding to each IGBT in each phase are respectively equal.

4. The real-time temperature acquisition circuit of the energy storage converter IGBT according to claim 1, characterized in that: The voltage-frequency conversion circuit includes a voltage-to-frequency signal chip, a crystal oscillator, a first photoelectric coupler, a first pull-up resistor, a first current-limiting resistor, and a second pull-up resistor; The signal input terminal of the voltage-to-frequency signal chip is connected to the output terminal of the voltage-to-frequency conversion circuit, the power supply terminal of the voltage-to-frequency signal chip is connected to the input terminal of the first photoelectric coupler via the first pull-up resistor and the first current-limiting resistor, and the frequency output terminal of the voltage-to-frequency signal chip is connected to the input terminal of the first photoelectric coupler via the first current-limiting resistor; the crystal oscillator is connected between the clock input terminal and the clock output terminal of the voltage-to-frequency signal chip; The output end of the first photoelectric coupler is connected to the processor and is connected to the first power supply through the second pull-up resistor.

5. The real-time temperature acquisition circuit of the energy storage converter IGBT according to any one of claims 1 to 4, characterized in that: Also includes: A voltage drop compensation circuit is connected between the voltage-frequency conversion circuit and the cathode of the first diode corresponding to each IGBT in the same phase.

6. The real-time temperature acquisition circuit of the energy storage converter IGBT according to claim 5, characterized in that: The voltage drop compensation circuit includes a signal sampling circuit and a second operational amplifier circuit connected in sequence, the signal sampling circuit includes a sampling power supply, a first sampling resistor, a second sampling resistor and a third sampling resistor, and the second operational amplifier circuit includes a second operational amplifier, a third inverting terminal resistor, a fourth inverting terminal resistor and a fifth inverting terminal resistor; A first end of the first sampling resistor is connected to the cathode of the first diode corresponding to each IGBT, a second end of the first sampling resistor is connected to the non-inverting input terminal of the second operational amplifier and is grounded through the second sampling resistor, and the sampling power supply is grounded through the third sampling resistor and the second sampling resistor; The first end of the third inverting terminal resistor and the first end of the fifth inverting terminal resistor are both grounded, the second end of the third inverting terminal resistor and the second end of the fifth inverting terminal resistor are both connected to the inverting input terminal of the second operational amplifier, and the inverting input terminal of the second operational amplifier is connected to the output terminal of the second operational amplifier through the fourth inverting terminal resistor; The output end of the second operational amplifier is connected to the voltage-frequency conversion circuit.

7. The real-time temperature acquisition circuit of the energy storage converter IGBT according to claim 6, characterized in that: The first sampling resistor and the third inverting terminal resistor have the same resistance value, the second sampling resistor and the fourth inverting terminal resistor have the same resistance value, and the third sampling resistor and the fifth inverting terminal resistor have the same resistance value.

8. An over-temperature protection circuit, characterized in that: include: a third pull-up resistor, a comparator, a second photocoupler, or a logic operation chip, a plurality of second diodes, and a plurality of level conversion chips; The anode of each second diode is respectively connected to the output end of the voltage drop compensation circuit of one phase in the real-time temperature acquisition circuit of the energy storage converter IGBT according to any one of claims 5 to 7 in a one-to-one correspondence, the cathode of each second diode is connected to the first input end of the comparator, and the second input end of the comparator is connected to the second power supply; The output end of the comparator is connected to the input end of the second photoelectric coupler, and is connected to the driving power supply through the third pull-up resistor; The output end of the second photoelectric coupler is connected to the first input end of the OR logic operation chip, the second input end of the OR logic operation chip is connected to the signal output end of the processor, the output end of the OR logic operation chip is connected to the enable end of each level conversion chip, the signal input end of each level conversion chip is used to receive the drive signal of the gate of each IGBT in one phase in the real-time temperature acquisition circuit, and the signal output end of each level conversion chip is respectively connected to the gate of each IGBT in one phase; The comparator is configured to compare the voltage signal inputted at the first input terminal with the second power supply voltage inputted at the second input terminal, and output a low level through the output terminal when the voltage signal inputted at the first input terminal is higher than or equal to the second power supply voltage; The processor is configured to compare the maximum digital frequency signal with an over-temperature protection threshold frequency, and output a high level through the signal output terminal when the maximum digital frequency signal is higher than or equal to the over-temperature protection threshold frequency.

9. The over-temperature protection circuit according to claim 8, characterized in that: Also includes: PWM drive conditioning circuit; The signal output end of each level conversion chip is connected to the gate of each IGBT in one phase through the PWM drive conditioning circuit.

10. The over-temperature protection circuit according to claim 8, characterized in that: Also includes a fourth pull-up resistor, a fifth pull-up resistor and a second current-limiting resistor; The second input terminal of the OR logic operation chip is connected to the third power supply through the fourth pull-up resistor; The output end of the second photocoupler is connected to the third power supply through the fifth pull-up resistor.

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