An IPM overcurrent and overtemperature protection circuit

Abstract

The present invention relates to an IPM overcurrent and overtemperature protection circuit, comprising a signal input terminal connected to an IPM module, a signal output terminal connected to an MCU module, and a comparison circuit connected between the signal input terminal and the signal output terminal, wherein the comparison circuit comprises a reference voltage output circuit connected to a power supply; a comparator, one input terminal of which is connected to the reference voltage output circuit to receive a reference voltage signal, the other input terminal of which is connected to the IPM module through the signal input terminal, and the output terminal of the comparator is connected to the MCU module through the signal output terminal; the signal input terminal is connected to a common output port of the temperature detection and overcurrent signal of the IPM module; the comparator compares the reference voltage with the voltage of the signal input terminal, and transmits the comparison result to the MCU module, so that the MCU module controls the operating state of the IPM module according to the comparison result. The present invention only occupies one pin of a single-chip microcomputer, and can provide protection for the IPM in case of overcurrent and overtemperature.

Description

Technical Field

[0001] The invention relates to an IPM protection circuit, in particular to an IPM overcurrent and overtemperature protection circuit. Background Art

[0002] With the development of the power electronics industry, the application field of IPM is becoming wider and wider. Compared with the ordinary IGBT+ drive solution, engineers pay more attention to this intelligent and miniaturized IPM solution. When the IPM is in use, it needs to be protected. In the case of overcurrent and overtemperature, the IPM needs to stop working to avoid damage. The Chinese invention patent with application number 201620760332.4 discloses a frequency converter protection circuit based on DSP and IPM modules, including: main controller circuit, IPM module circuit, overvoltage protection circuit, overtemperature protection circuit, overcurrent protection circuit and fault blocking circuit; it uses TI's DSP control chip TMS320LF2406 and IR's intelligent power module IPM module IRAMS10UP60B, and samples the DC bus voltage, and transmits the temperature and current signals inside the IPM module to the main controller TMS320LF24 06, compare and analyze the data to determine whether the circuit has dangerous conditions such as overvoltage, overtemperature and overcurrent. If there is a danger, the main controller sends out blocking signals FAULT and PDPINTA, where FAULT is used to block the SVPWM pulse of the IPM module, and PDPINTA blocks the six SVPWM pulses generated by TMS320LF2406. At the same time, TMS320LF2406 sends out IPM_EN signal to block 74AC244, realizing multi-faceted and multiple closed-loop circuit protection based on software and hardware, and realizing safe and reliable operation of the inverter. The over-temperature protection circuit and over-current protection circuit of this patent occupy an input pin of the main controller (single-chip microcomputer) separately, resulting in a waste of pin resources, and its circuit structure is also relatively complex.

[0003] The present invention is proposed in view of the above. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and to provide an IPM overcurrent and overtemperature protection circuit which only occupies one pin of a single chip microcomputer and can provide protection for the IPM in the event of overcurrent and overtemperature.

[0005] In order to achieve this object, the present invention adopts the following technical solution:

[0006] An IPM overcurrent and overtemperature protection circuit includes a signal input terminal connected to an IPM module, a signal output terminal connected to an MCU module, and a comparison circuit connected between the signal input terminal and the signal output terminal, wherein the comparison circuit includes:

[0007] A reference voltage output circuit is connected to the power supply and configured to output a reference voltage;

[0008] A comparator, one input end of which is connected to the reference voltage output circuit to receive the reference voltage signal, the other input end of which is connected to the IPM module through the signal input end, and the output end of the comparator is connected to the MCU module through the signal output end;

[0009] The signal input terminal is connected to the temperature detection and overcurrent signal common output port of the IPM module;

[0010] The comparator is configured to compare the reference voltage with the voltage at the signal input terminal, and transmit the comparison result to the MCU module, so that the MCU module controls the operating state of the IPM module according to the comparison result.

[0011] Furthermore, when the voltage at the signal input terminal is greater than the reference voltage, the comparator is configured to output a high-level signal, and the MCU module controls the IPM module to maintain the running state; when the voltage at the signal input terminal is less than the reference voltage, the comparator is configured to output a low-level signal, and the MCU module controls the IPM module to stop running.

[0012] Furthermore, the comparison circuit further includes a comparison resistor R3, one end of which is connected to the power supply, and the other end of which is connected in series with the thermistor in the IPM module through the signal input end.

[0013] Furthermore, the resistance value of the comparison resistor R3 is configured to be the same as the resistance value of the thermistor at a certain temperature, and the temperature is the protection temperature of the IPM module.

[0014] Furthermore, the reference voltage output circuit includes a resistor R1 and a resistor R2 connected in series, and an input terminal of the comparator is connected between the resistor R1 and the resistor R2.

[0015] Furthermore, the resistance values ​​of the resistor R1 and the resistor R2 are the same, and the reference voltage is 1 / 2 of the power supply voltage.

[0016] Furthermore, a resistor R5 is provided between the output terminal and the signal output terminal of the comparator, and the resistor R5 is connected to the power supply through the resistor R4.

[0017] Furthermore, the input terminal and the output terminal of the comparator are also connected to the ground via a capacitor respectively.

[0018] Furthermore, the reference voltage is added to the inverting input terminal of the comparator, and the output signal of the IPM module is added to the non-inverting input terminal of the comparator.

[0019] Furthermore, the common output port of the temperature detection and overcurrent signal is the VFO output port of the IPM module, and the model of the IPM module is IKCM15L60.

[0020] The technical solution of the present invention brings the following beneficial effects:

[0021] The signal output end of the present invention only occupies one pin of the MCU module (single-chip microcomputer), and can trigger the MCU action when the IPM is over-current or over-temperature, so that it controls the IPM module to stop working, thereby protecting the IPM module. Compared with the traditional IPM protection circuit that needs to occupy at least two MCU pins, since the present invention only occupies one pin of the MCU, one MCU module can control more IPM modules, effectively reducing the purchase quantity and use cost of the MCU module, and the overall circuit structure is simpler and more stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 : A circuit diagram of an embodiment of the present invention;

[0023] Figure 2 : An internal electrical schematic diagram of an IPM module in an embodiment of the present invention;

[0024] Among them: 1. IPM module 2. comparison circuit 3. MCU module 4. signal input terminal 5. signal output terminal. DETAILED DESCRIPTION

[0025] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings.

[0026] like Figure 1 and Figure 2 As shown, an IPM overcurrent and overtemperature protection circuit includes a signal input terminal 4 for connecting to an IPM module 1, a signal output terminal 5 for connecting to an MCU module 3, and a comparison circuit 2 connected between the signal input terminal 4 and the signal output terminal 5. The model of the IPM module 1 described in this embodiment is IKCM15L60, but it is not limited to this. The IPM module 1 of the IKCM15L60 type outputs temperature protection and overcurrent protection as a pin VFO. A thermistor is provided inside, and the thermistor is connected in series between the pin VFO and the pin VSS, wherein the pin VSS is grounded.

[0027] The comparison circuit 2 includes a reference voltage output circuit, a comparator ICA and a comparison resistor R3.

[0028] The reference voltage output circuit is connected to a power supply VCC and is configured to output a reference voltage. Specifically, the reference voltage output circuit includes a resistor R1 and a resistor R2 connected in series, wherein one end of the resistor R1 is connected to the power supply VCC, one end of the resistor R2 is grounded, the resistance values ​​of the resistor R1 and the resistor R2 are the same, and the voltage on each resistor is 1 / 2 of the voltage of the power supply VCC.

[0029] The inverting input terminal of the comparator ICA is connected to the reference voltage output circuit to receive the reference voltage signal. Specifically, the inverting input terminal of the comparator ICA is connected between the resistor R1 and the resistor R2, so that the reference voltage input to the comparator ICA is 1 / 2 of the power supply VCC voltage. The in-phase input terminal of the comparator ICA is connected to the IPM module 1 through the signal input terminal 4, specifically, the signal input terminal 4 is connected to the temperature detection and overcurrent signal common output port of the IPM module 1, that is, the pin VFO. The output terminal of the comparator ICA is connected to the MCU module 3 through the signal output terminal 5.

[0030] The function of the comparator ICA is to compare the reference voltage with the voltage of the signal input terminal 4, and to reflect the comparison result with a high level or a low level at the output terminal, and to transmit the comparison result to the MCU module 3, so that the MCU module 3 controls the operation state of the IPM module 1 according to the comparison result. Specifically, when the voltage of the signal input terminal 4 is greater than the reference voltage, the comparator ICA is configured to output a high level signal, and the MCU module 3 controls the IPM module 1 to maintain the operation state; when the voltage of the signal input terminal 4 is less than the reference voltage, the comparator ICA is configured to output a low level signal, and the MCU module 3 controls the IPM module 1 to stop operating.

[0031] The overcurrent protection process is as follows: when IPM module 1 is overcurrent, the ITRIP current detection triggers the pin VFO to output a low level, which is compared with the reference voltage of the comparator ICA and outputs a low level to the MCU module 3. The MCU module 3 detects the level flip, thereby shutting off the six-channel PWM output, stopping the IPM module 1 from working, and protecting the IPM module 1 from damage.

[0032] One end of the comparison resistor R3 is connected to the power supply VCC, and the other end is connected in series with the thermistor in the IPM module 1 through the signal input terminal 4. The resistance of the thermistor changes with the temperature. Specifically, the thermistor is an NTC resistor, and the higher the temperature, the lower the resistance. Since the thermistor is connected in series with the comparison resistor R3, when the resistance of the thermistor changes, the voltage of the signal input terminal 4 will change. When the voltage of the signal input terminal 4 is less than the reference voltage, the MCU module 3 will be triggered to control the IPM module 1 to stop running.

[0033] Preferably, the resistance value of the comparison resistor R3 is configured to be the same as the resistance value of the thermistor Thermistor at a certain temperature, and the temperature is the protection temperature of the IPM module 1 .

[0034] The process of over-temperature protection is as follows: when the outside temperature is higher than the protection temperature, the resistance of the thermistor will be smaller than the comparison resistor R3, so that the voltage of the signal input terminal 4 is smaller than the reference voltage, and the comparator ICA outputs a low-level signal to the MCU module 3. The MCU module 3 detects the level flip, thereby turning off the six-way PWM output, stopping the IPM module 1 from working, and protecting the IPM from damage.

[0035] Preferably, a resistor R5 is further provided between the output end of the comparator ICA and the signal output end 5, and the resistor R5 is connected to the power supply VCC through the resistor R4.

[0036] Preferably, the input terminal and the output terminal of the comparator ICA are also connected to the ground via a capacitor respectively, so as to block direct current and pass alternating current.

[0037] The above is an embodiment of the present invention. It should be pointed out that for ordinary technicians in this field, various modifications and improvements can be made without departing from the principle of the present invention, which should also be regarded as the protection scope of the present invention.

Claims

1. An IPM overcurrent and overtemperature protection circuit, comprising a signal input terminal connected to an IPM module, a signal output terminal connected to an MCU module, and a comparison circuit connected between the signal input terminal and the signal output terminal, characterized in that: The comparison circuit comprises: A reference voltage output circuit is connected to the power supply and configured to output a reference voltage; A comparator, one input end of which is connected to the reference voltage output circuit to receive the reference voltage signal, the other input end of which is connected to the IPM module through the signal input end, and the output end of the comparator is connected to the MCU module through the signal output end; The signal input terminal is connected to the temperature detection and overcurrent signal common output port of the IPM module; the output port is the pin VFO of the IPM module; The comparator is configured to compare the reference voltage with the voltage at the signal input terminal, and transmit the comparison result to the MCU module, so that the MCU module controls the operation state of the IPM module according to the comparison result; When the voltage of the signal input terminal is greater than the reference voltage, the comparator is configured to output a high-level signal, and the MCU module controls the IPM module to keep running; when the voltage of the signal input terminal is less than the reference voltage, the comparator is configured to output a low-level signal, and the MCU module controls the IPM module to stop running; When the IPM module is over-current, the ITRIP current detection triggers the pin VFO to output a low level, which is compared with the reference voltage of the comparator and outputs a low level to the MCU module. The MCU module detects the level flip and turns off the six-way PWM output, causing the IPM module to stop working. The comparison circuit further includes a comparison resistor R3, one end of which is connected to the power supply, and the other end of which is connected in series with the thermistor in the IPM module through the signal input end; The resistance value of the comparison resistor R3 is configured to be the same as the resistance value of the thermistor at a certain temperature, and the temperature is the protection temperature of the IPM module; When the outside temperature is higher than the protection temperature, the resistance of the thermistor will be smaller than the comparison resistor R3, making the voltage at the signal input terminal smaller than the reference voltage. The comparator ICA outputs a low-level signal to the MCU module. The MCU module detects the level flip and shuts off the six-channel PWM output, causing the IPM module to stop working.

2. The IPM overcurrent and overtemperature protection circuit according to claim 1, characterized in that: The reference voltage output circuit includes a resistor R1 and a resistor R2 connected in series, and an input terminal of the comparator is connected between the resistor R1 and the resistor R2.

3. An IPM overcurrent and overtemperature protection circuit according to claim 2, characterized in that: The resistance values ​​of the resistor R1 and the resistor R2 are the same, and the reference voltage is 1 / 2 of the power supply voltage.

4. The IPM overcurrent and overtemperature protection circuit according to claim 1, characterized in that: A resistor R5 is further provided between the output end and the signal output end of the comparator, and the resistor R5 is connected to the power supply through the resistor R4.

5. The IPM overcurrent and overtemperature protection circuit according to claim 1, characterized in that: The input terminal and the output terminal of the comparator are also connected to the ground via a capacitor respectively.

6. The IPM overcurrent and overtemperature protection circuit according to claim 1, characterized in that: The reference voltage is added to the inverting input terminal of the comparator, and the output signal of the IPM module is added to the non-inverting input terminal of the comparator.

7. The IPM overcurrent and overtemperature protection circuit according to claim 1, characterized in that: The common output port of the temperature detection and over-current signal is the VFO output port of the IPM module, and the model of the IPM module is IKCM15L60.

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