Control circuit for ptc and compressor

Abstract

A PTC and compressor two-in-one control circuit, comprising: a driving circuit and a temperature control circuit, the temperature control circuit comprising: a PTC, an IGBT1, a compressor, an IGBT2-H and an IGBT2-L, the positive pole of a high-voltage socket is connected with one end of the PTC and the C end of the IGBT2-H, the other end of the PTC is connected with the C end of the IGBT1, the output end of the IGBT driving 1 of the driving circuit is connected with the G end of the IGBT1, the E end of the IGBT2-H is connected with the C end of the IGBT2-L and the compressor, the output end of the IGBT driving 2 of the driving circuit is connected with the G end of the IGBT2-H and the IGBT2-L, the E end of the IGBT1 and the E end of the IGBT2-L are connected with the negative pole of the high-voltage socket. The above-mentioned driving circuit can control the PTC and the compressor at the same time, reduces the overall cost of the circuit, reduces the space occupied by the circuit, and simplifies the maintenance process.

Description

Technical Field

[0001] This utility model relates to control circuits, and more particularly to a control circuit that combines a PTC and a compressor. Background Technology

[0002] As the market share of new energy vehicles gradually increases, people's requirements for new energy vehicles are also getting higher and higher. At present, the temperature control system of new energy vehicles is usually equipped with a compressor and a PTC heater. The PTC is used to heat to achieve the heating function, and the compressor is used to compress the refrigerant to achieve the cooling function.

[0003] However, most existing new energy vehicles use two independent control circuits to control the compressor and PTC respectively. This design has poor coordination, which leads to a significant reduction in range. On the other hand, it increases the overall vehicle cost and size requirements. Utility Model Content

[0004] In order to overcome the shortcomings and deficiencies of the existing technology, the purpose of this utility model is to design a control circuit that combines PTC and compressor, so as to simultaneously control the PTC heater and compressor through the same control circuit, thereby improving their synergy and reducing the overall vehicle cost and size requirements.

[0005] To achieve the above objectives, this utility model provides a control circuit combining a PTC and a compressor, comprising: a drive circuit and a temperature control circuit. The drive circuit includes: a low-voltage side circuit, a high-voltage side circuit, an isolation transformer, an isolation communication chip, and an isolation optocoupler. The low-voltage side circuit includes: a low-voltage side MCU and a CAN interface chip. A low-voltage socket is connected to the power supply pin of the low-voltage side MCU, and a CAN bus is connected to the CAN interface chip. The high-voltage side circuit includes: a high-voltage side MCU, IGBT driver 1, and IGBT driver 2. The high-voltage side MCU is simultaneously connected to the input terminals of both IGBT driver 1 and IGBT driver 2. The low-voltage socket and the low-voltage side MCU are both connected to the input terminal of the isolation transformer. The output terminal of the isolation transformer is simultaneously connected to the power supply pin of the high-voltage side MCU, the power supply pin of IGBT driver 1, and the IGBT driver 2. The power supply pin of GBT driver 2 is connected. The CAN interface chip is interconnected with the high-voltage side MCU through an isolation communication chip, and the low-voltage side MCU is interconnected with the high-voltage side MCU through an isolation optocoupler. The temperature control circuit includes: PTC, IGBT1, compressor, IGBT2-H, and IGBT2-L. The positive terminal of a high-voltage socket is connected to one end of PTC and the C terminal of IGBT2-H. The other end of PTC is connected to the C terminal of IGBT1. The output terminal of IGBT driver 1 is connected to the G terminal of IGBT1. The E terminal of IGBT2-H is connected to the C terminal of IGBT2-L and the compressor. The output terminal of IGBT driver 2 is connected to the G terminals of both IGBT2-H and IGBT2-L. The E terminals of IGBT1 and IGBT2-L are both connected to the negative terminal of the high-voltage socket. The heating circuit integrates a PTC and a compressor, achieving a two-in-one heating and cooling function. Since the control circuit can be arranged on a single PCB or control box, space is saved. Since two sets of repetitive components can be avoided, the overall cost is reduced. Since the control logic of the PTC and compressor can be set using a unified software architecture, the maintenance process is simplified. The isolation transformer, isolation optocoupler and isolation communication chip isolate the low-voltage side and high-voltage side of the drive circuit.

[0006] Furthermore, the drive circuit also includes an EMI filter, LDO1, and LDO2. The low-voltage socket is connected to the input terminal of the EMI filter, and the output terminal of the EMI filter is connected to both LDO1 and LDO2. LDO1 is connected to the power supply pin of the low-voltage side MCU, the low-voltage side MCU is connected to the input terminal of LDO2, and the output terminal of LDO2 is connected to the input terminal of the isolation transformer. The EMI filter filters the current input to the low-voltage socket; LDO1 and LDO2 stabilize the power supply to the low-voltage socket and transmit the stabilized power to the low-voltage side MCU and the isolation transformer.

[0007] Furthermore, the high-voltage side circuit also includes an LDO3, the output terminal of which is connected to the input terminal of the isolation transformer, and the output terminal of the LDO3 is connected to the power supply pin of the high-voltage side MCU. The LDO3 serves to stabilize the power supply from the isolation transformer and transmit the stabilized power to the high-voltage side MCU.

[0008] Furthermore, the temperature control circuit also includes a voltage sampling module, a current sampling module 1, and a current sampling module 2. The positive terminal of the high-voltage socket is connected to the input terminal of the voltage sampling module. The output terminal (E) of IGBT 1 is connected to the input terminal of current sampling module 1, and the output terminal (E) of IGBT 2-L is connected to the input terminal of current sampling module 2. The sampling terminals of current sampling modules 1, 2, and 3 are all connected to the high-voltage side MCU. The output terminals of the voltage sampling module, current sampling module 1, and current sampling module 2 are all connected to the negative terminal of the high-voltage socket. The voltage sampling module, current sampling module 1, and current sampling module 2 can sample the voltage and current in the temperature control circuit, and the high-voltage side MCU can be used to determine whether the voltage and current values ​​are normal.

[0009] Furthermore, the voltage sampling module includes: a voltage divider resistor 1 and a sampling resistor. The positive terminal of the high-voltage socket, the voltage divider resistor 1, the sampling resistor, and the negative terminal of the high-voltage socket are connected in sequence. The input terminal of the sampling resistor is connected to the high-voltage side MCU. The current sampling module 1 includes: a shunt 1 and an operational amplifier 1. The output terminal of the IGBT 1 is connected to the input terminal of the shunt 1. The output terminal of the shunt 1 is connected to the negative terminal of the high-voltage socket. The input terminal of the shunt 1 is connected to the input terminal of the operational amplifier 1. The output terminal of the operational amplifier 1 is connected to the high-voltage side MCU. The current sampling module 2 includes: a shunt 2 and an operational amplifier 2. The output terminal of the IGBT 2-L is connected to the input terminal of the shunt 2. The output terminal of the shunt 2 is connected to the negative terminal of the high-voltage socket. The input terminal of the shunt 2 is connected to the input terminal of the operational amplifier 2. The output terminal of the operational amplifier 2 is connected to the high-voltage side MCU. Among them, setting voltage divider resistor 1 can achieve voltage reduction, thereby enabling sampling of large voltage; setting shunt 1 and shunt 2 can enable sampling of large current.

[0010] Furthermore, there are two PTCs and two IGBTs. The output terminal of the IGBT driver 1 is connected to the gate (G) terminals of both IGBTs simultaneously. The other terminals of the two PTCs are connected to the collector (C) terminals of the two IGBTs respectively, and the emitter (E) terminals of both IGBTs are connected to the input terminals of the shunt 1. The use of two PTCs enables separate heating of multiple locations within the vehicle.

[0011] Furthermore, there are three IGBT drivers 2, compressors, IGBT2-H, IGBT2-L, shunts 2, and operational amplifiers 2. The output of each IGBT driver 2 is simultaneously connected to the gate (G) terminal of one IGBT2-H and one IGBT2-L. The emitter (E) terminals of the three IGBT2-Hs are connected to the collector (C) terminals of the three IGBT2-Ls, the collector (C) terminals of the three IGBT2-Ls are connected to the three compressors, and the emitter (E) terminals of the three IGBT2-Ls are connected to the input terminals of the three shunts 2. The voltage divider at the input terminals of the three shunts 2 is connected to the input terminals of the three operational amplifiers 2. The use of multiple compressors enables separate cooling of multiple locations within the vehicle.

[0012] Furthermore, the control circuit also includes a temperature acquisition circuit, which is connected to the low-voltage side MCU. The temperature acquisition circuit is configured to collect the vehicle's temperature values.

[0013] Furthermore, the temperature acquisition circuit includes a voltage divider resistor 2 and an NTC. A temperature acquisition power supply is connected to one end of the voltage divider resistor 2, the other end of the voltage divider resistor 2 is connected to one end of the NTC, the other end of the NTC is grounded, and one end of the NTC is connected to the low-voltage side MCU. The temperature acquisition circuit uses the resistance value of the NTC to provide temperature feedback.

[0014] Furthermore, there are three temperature acquisition circuits, all of which are connected to the low-voltage side MCU. The presence of three temperature acquisition circuits allows for the separate acquisition of temperatures at multiple locations within the vehicle. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the control circuit involved in this utility model; Figure 2 This is a schematic diagram of the temperature control circuit involved in this utility model; Figure 3 This is a schematic diagram of the temperature acquisition circuit involved in this utility model. Detailed Implementation

[0016] The technical solution of this utility model will be further described below through embodiments: like Figure 1 As shown, this utility model provides a control circuit that integrates a PTC and a compressor, including: a drive circuit, a temperature control circuit, and a temperature acquisition circuit. The temperature acquisition circuit is connected to the drive circuit, and the drive circuit and the temperature control circuit are interconnected. When the control circuit is working, the temperature acquisition circuit transmits temperature information to the drive circuit, and the drive circuit controls the temperature control circuit according to the temperature information, thereby causing the PTC and the compressor to work.

[0017] Specifically, the drive circuit includes: a low-voltage side circuit, a high-voltage side circuit, an isolation transformer, an isolation communication chip, and an isolation optocoupler; the low-voltage side circuit includes: a low-voltage side MCU, an EMI filter, LDO1, LDO2, and a CAN interface chip. The low-voltage socket is connected to the input terminal of the EMI filter, and the output terminal of the EMI filter is connected to both the input terminals of LDO1 and LDO2. The output terminal of LDO1 is connected to the power supply pin of the low-voltage side MCU. The temperature acquisition circuit is connected to the low-voltage side MCU, and the low-voltage side MCU is connected to the input terminal of LDO2. The CAN bus is connected to the CAN interface chip; the high-voltage side circuit includes: a high-voltage side MCU, LDO3, IGBT driver 1, and... The outputs of IGBT driver 2 and LDO3 are connected to the power supply pins of the high-voltage side MCU. The high-voltage side MCU is also connected to the inputs of both IGBT driver 1 and IGBT driver 2. The outputs of IGBT driver 1 and IGBT driver 2 are respectively connected to the temperature control circuit, which is connected to the high-voltage side MCU. The output of LDO2 is connected to the input of the isolation transformer. The output of the isolation transformer is also connected to the input of LDO3, the power supply pins of IGBT driver 1 and IGBT driver 2. The CAN interface chip is interconnected with the high-voltage side MCU through an isolation communication chip, and the low-voltage side MCU is interconnected with the high-voltage side MCU through an isolation optocoupler.When the drive circuit is working, the low-voltage socket outputs 12V low-voltage power to the EMI filter. After filtering the current, the EMI filter outputs low voltage to LDO1 and LDO2. LDO1 reduces the voltage to 5V and outputs it to the low-voltage side MCU. LDO2 reduces the voltage to 5V and outputs it to the isolation transformer. The isolation transformer then transforms the voltage to 15V and outputs it to LDO3, IGBT driver 1, and IGBT driver 2. LDO3 reduces the voltage to 5V and outputs it to the high-voltage side MCU, thus powering the low-voltage side MCU, high-voltage side MCU, IGBT driver 1, and IGBT driver 2. LDO1, LDO2, and LDO3 are voltage regulators, and their working principle is the same as in existing technologies, so it will not be described further here. The temperature acquisition circuit inputs a temperature acquisition signal to the low-voltage side MCU. The low-voltage side MCU outputs a feedback signal based on the signal input from the temperature acquisition circuit and inputs the feedback signal to the high-voltage side MCU through an isolation optocoupler. The high-voltage side MCU outputs the feedback signal to IGBT driver 1 and IGBT driver 2. Control signals: IGBT driver 1 and IGBT driver 2 output drive signals to the temperature control circuit, thereby driving the PTC and compressor to work. In addition, the low-voltage side MCU can also control the on / off state of LDO2, thereby controlling the on / off state of the high-voltage side circuit. The isolation optocoupler is used to isolate interference between the low-voltage side circuit and the high-voltage side circuit. Its working principle is the same as that of the prior art. The low-voltage side MCU and the high-voltage side MCU act as microprocessors, and IGBT driver 1 and IGBT driver 2 act as IGBT drivers. Their working principles are also the same as those of the microprocessors and IGBT drivers in the prior art, and will not be described in detail here. The CAN bus outputs bus signals to the CAN interface chip. The CAN interface chip outputs feedback signals to the high-voltage side MCU through the isolation communication chip. The CAN interface chip is used to process CAN bus signals, and the isolation communication chip realizes signal coupling and transmission in an electrically isolated state. The working principles of the CAN interface chip and the isolation communication chip are the same as those of the prior art, and will not be described in detail here.

[0018] In this embodiment, the low-voltage side MCU uses the KF8A100CSD microprocessor from Shanghai ChipON Microelectronics Technology Co., Ltd.; the high-voltage side MCU uses the GD32A503RCT3 microprocessor from GigaDevice Semiconductor Co., Ltd.; the CAN interface chip uses the MCP2561E CAN transceiver from Microchip Technology Corporation; and the isolation communication chip uses the NSi8221N1-DSPR from Nanochip Technology Co., Ltd. Of course, in other embodiments, the low-voltage side MCU and the high-voltage side MCU can also use other models of microprocessors, and the CAN interface chip and the isolation communication chip can also use other models of chips.

[0019] Specifically, the temperature control circuit includes: a voltage sampling module, a PTC, IGBT1, a current sampling module 1, a compressor, IGBT2-H, IGBT2-L, and a current sampling module 2. The positive terminal HV+ of the high-voltage socket is simultaneously connected to the input terminal of the voltage sampling module, one end of the PTC, and the C terminal of IGBT2-H; the other end of the PTC is connected to the C terminal of IGBT1; the output terminal of IGBT driver 1 is connected to the G terminal of IGBT1; the E terminal of IGBT1 is connected to the input terminal of current sampling module 1; and the sampling terminal of current sampling module 1 is connected to the high-voltage side MCU. The E terminal of IGBT2-H is simultaneously connected to the C terminal of IGBT2-L and the compressor; the output terminal of IGBT driver 2 is simultaneously connected to the G terminals of both IGBT2-H and IGBT2-L; the E terminal of IGBT2-L is connected to the input terminal of current sampling module 2; and the sampling terminal of current sampling module 2 is connected to the high-voltage side MCU. The output terminals of the voltage sampling module, current sampling module 1, and current sampling module 2 are all connected to the negative terminal HV- of the high-voltage socket. When the temperature control circuit is operating, high-voltage electricity is input to the high-voltage socket. IGBT driver 1 is used to control the switching of IGBT1, thereby controlling the operation of the PTC. IGBT driver 2 is used to control the switching of IGBT2-H and IGBT2-L, thereby controlling the operation of the compressor motor. The voltage sampling module feeds back voltage information to the high-voltage side MCU, and current sampling modules 1 and 2 feed back current information to the high-voltage side MCU, thereby determining whether the voltage and current values ​​in the temperature control circuit are normal. IGBT2-H and IGBT2-L are both connected to the compressor motor, and the motor speed is controlled collaboratively by IGBT2-H and IGBT2-L.

[0020] More specifically, such as Figure 2As shown, the voltage sampling module includes: a voltage divider resistor 1 and a sampling resistor. The positive terminal HV+ of the high-voltage socket, the voltage divider resistor 1, the sampling resistor, and the negative terminal HV- of the high-voltage socket are connected in sequence. The input terminal of the sampling resistor is connected to the high-voltage side MCU. The current sampling module 1 includes: a shunt 1 and an operational amplifier 1. The E terminal of IGBT 1 is connected to the input terminal of the shunt 1. The output terminal of the shunt 1 is connected to the negative terminal HV- of the high-voltage socket. The input terminal of the shunt 1 is connected to the input terminal of the operational amplifier 1. The output terminal of the operational amplifier 1 is connected to the high-voltage side MCU. The current sampling module 2 includes: a shunt 2 and an operational amplifier 2. The E terminal of IGBT 2-L is connected to the input terminal of the shunt 2. The output terminal of the shunt 2 is connected to the negative terminal HV- of the high-voltage socket. The input terminal of the shunt 2 is connected to the input terminal of the operational amplifier 2. The output terminal of the operational amplifier 2 is connected to the high-voltage side MCU. When the temperature control circuit is operating, voltage divider resistor 1 is used to reduce the voltage at the input terminal of the sampling resistor, allowing the high-voltage side MCU to determine whether the voltage value of the heater circuit is normal. Shunt 1 is used to reduce the output voltage of IGBT1, and outputs it to the high-voltage side MCU through operational amplifier 1, thereby determining whether the current value of the PTC circuit is normal. Shunt 2 is used to reduce the output voltage of IGBT2-H and IGBT2-L, and outputs it to the high-voltage side MCU through operational amplifier 2, thereby determining whether the current value of the compressor circuit is normal. Operational amplifiers 1 and 2 are both operational amplifiers used to compare the difference between the current value of the heater circuit and the set current value.

[0021] In this embodiment, there are two PTCs and two IGBTs. The output terminal of IGBT driver 1 is connected to the gate (G) terminals of both IGBTs. The other terminals of the two PTCs are connected to the collector (C) terminals of the two IGBTs, respectively. The emitter (E) terminals of both IGBTs are connected to the input terminal of shunt 1. Of course, in other embodiments, the number of the above components can be three or more.

[0022] In this embodiment, there are three IGBT drivers 2, compressors, IGBT2-H, IGBT2-L, shunts 2, and operational amplifiers 2. The output of each IGBT driver 2 is simultaneously connected to the gate (G) terminal of one IGBT2-H and the gate (G) terminal of one IGBT2-L. The emitter (E) terminals of the three IGBT2-Hs are respectively connected to the collector (C) terminals of the three IGBT2-Ls. The collector (C) terminals of the three IGBT2-Ls are respectively connected to the three compressors. The emitter (E) terminals of the three IGBT2-Ls are respectively connected to the input terminals of the three shunts 2. The voltage divider at the input terminals of the three shunts 2 is connected to the input terminals of the three operational amplifiers 2. Of course, in other embodiments, the number of the above components can be four or more.

[0023] More specifically, such as Figure 3As shown, the temperature acquisition circuit includes: a voltage divider resistor 2 and an NTC. The temperature acquisition power supply is connected to one end of the voltage divider resistor 2, and the other end of the voltage divider resistor 2 is connected to one end of the NTC. The other end of the NTC is grounded, and one end of the NTC is connected to the low-voltage side MCU. When the temperature acquisition circuit is working, the temperature acquisition power supply supplies power to the voltage divider resistor 2. The temperature acquisition power supply is a 5V power supply. The voltage divider resistor 2 is used to reduce the voltage at the input terminal of the NTC. The NTC, or thermistor, reflects the ambient temperature value through its input terminal. It is connected to the low-voltage side MCU through its input terminal to achieve temperature information acquisition.

[0024] In this embodiment, there are three temperature acquisition circuits, all of which are connected to the low-voltage side MCU. Of course, in other embodiments, the number of temperature acquisition circuits can be four or more.

[0025] The above-mentioned control circuit combining the PTC and compressor has the following advantages: 1. Reduced vehicle space and weight: Traditional PTC and compressor control boards are designed independently, requiring separate PCBs, connectors, wiring harnesses, and heat dissipation structures, which occupy a lot of space in the vehicle, such as the battery pack, motor compartment, or passenger compartment. However, the control circuit of this invention can be arranged on the same PCB or in a compact control box, which significantly reduces the number of electronic components, such as capacitors, resistors, chips, and connectors, and also shortens the wiring harness length. The overall volume can be reduced by 30% to 50%, and the weight by about 20% to 30%, which is beneficial to the improvement of the range of new energy vehicles (i.e., reducing redundant mass) and the layout of the vehicle's interior space, freeing up space for the battery or passengers.

[0026] 2. Reduced costs and increased production efficiency: By reducing repetitive components such as power chips, MCUs, and sampling resistors, and by decreasing the use of auxiliary materials such as wire harnesses, material costs are saved. Furthermore, assembly processes such as welding, testing, and debugging can be simplified from two sets to one, shortening production line hours, increasing the utilization rate of labor and equipment, and reducing manufacturing costs by approximately 20% to 35%.

[0027] 3. Optimized Control Coordination for Improved Thermal Management Efficiency: Traditional PTC and compressor controllers are designed independently, often leading to energy waste due to thermal mismatch. However, in the control circuit of this invention, since the PTC and compressor are integrated on the same PCB and controlled by the same high-voltage side MCU, the model predictive control (MPC) algorithm can predict temperature change trends and adjust the compressor speed and PTC power distribution in advance, avoiding energy consumption peaks caused by frequent start-stop cycles. Furthermore, during heating, the PTC power can be dynamically adjusted according to the compressor speed, while during cooling, PTC false triggering can be suppressed, and the waste heat from the compressor exhaust can be used to preheat the PTC, improving energy recovery efficiency.

[0028] 4. Simplified Software Maintenance and Upgrades: A unified software architecture can be used to configure the control logic of the PTC and compressor, such as PID regulation and fault diagnosis, making maintenance more convenient. Furthermore, function upgrades only require updating one set of software, eliminating the need to debug two separate control boards, significantly reducing the complexity and time cost of OTA upgrades. In addition, underlying drivers, such as PWM output and ADC sampling, can be shared, thereby reducing code redundancy.

Claims

1. A control circuit combining a PTC and a compressor, comprising: The driving circuit and temperature control circuit are characterized by: The driving circuit includes: a low-voltage side circuit, a high-voltage side circuit, an isolation transformer, an isolation communication chip, and an isolation optocoupler; the low-voltage side circuit includes: a low-voltage side MCU and a CAN interface chip, a low-voltage socket connected to the power supply pin of the low-voltage side MCU, and a CAN bus connected to the CAN interface chip; the high-voltage side circuit includes: a high-voltage side MCU, IGBT driver 1, and IGBT driver 2, the high-voltage side MCU being connected to the input terminals of both IGBT driver 1 and IGBT driver 2; the low-voltage socket and the low-voltage side MCU are both connected to the input terminal of the isolation transformer, the output terminal of the isolation transformer being connected to the power supply pins of the high-voltage side MCU, IGBT driver 1, and IGBT driver 2; the CAN interface chip and the high-voltage side MCU are interconnected through the isolation communication chip; the low-voltage side MCU and the high-voltage side MCU are interconnected through the isolation optocoupler. The temperature control circuit includes: a PTC, IGBT1, a compressor, IGBT2-H, and IGBT2-L. The positive terminal of a high-voltage socket is connected to one end of the PTC and the C terminal of IGBT2-H. The other end of the PTC is connected to the C terminal of IGBT1. The output terminal of IGBT driver 1 is connected to the G terminal of IGBT1. The E terminal of IGBT2-H is connected to the C terminal of IGBT2-L and the compressor. The output terminal of IGBT driver 2 is connected to the G terminals of both IGBT2-H and IGBT2-L. The E terminals of IGBT1 and IGBT2-L are both connected to the negative terminal of the high-voltage socket.

2. The control circuit combining PTC and compressor according to claim 1, characterized in that: The driving circuit also includes an EMI filter, LDO1, and LDO2. The low-voltage socket is connected to the input terminal of the EMI filter, and the output terminal of the EMI filter is connected to both LDO1 and LDO2. LDO1 is connected to the power supply pin of the low-voltage side MCU, the low-voltage side MCU is connected to the input terminal of LDO2, and the output terminal of LDO2 is connected to the input terminal of the isolation transformer.

3. The control circuit combining PTC and compressor according to claim 1, characterized in that: The high-voltage side circuit also includes an LDO3, the output terminal of the isolation transformer is connected to the input terminal of the LDO3, and the output terminal of the LDO3 is connected to the power supply pin of the high-voltage side MCU.

4. The control circuit combining PTC and compressor according to claim 1, characterized in that: The temperature control circuit further includes a voltage sampling module, a current sampling module 1, and a current sampling module 2. The positive terminal of the high-voltage socket is connected to the input terminal of the voltage sampling module. The E terminal of IGBT 1 is connected to the input terminal of the current sampling module 1. The E terminal of IGBT 2-L is connected to the input terminal of the current sampling module 2. The sampling terminals of the current sampling modules 1, 2, and 2 are all connected to the high-voltage side MCU. The output terminals of the voltage sampling module, 1, and 2 are all connected to the negative terminal of the high-voltage socket.

5. The control circuit combining PTC and compressor according to claim 4, characterized in that: The voltage sampling module includes a voltage divider resistor 1 and a sampling resistor. The positive terminal of the high-voltage socket, the voltage divider resistor 1, the sampling resistor, and the negative terminal of the high-voltage socket are connected in sequence. The input terminal of the sampling resistor is connected to the high-voltage side MCU. The current sampling module 1 includes a shunt 1 and an operational amplifier 1. The output terminal of the IGBT 1 is connected to the input terminal of the shunt 1. The output terminal of the shunt 1 is connected to the negative terminal of the high-voltage socket. The input terminal of the shunt 1 is connected to the input terminal of the operational amplifier 1. The output terminal of the operational amplifier 1 is connected to the high-voltage side MCU. The current sampling module 2 includes a shunt 2 and an operational amplifier 2. The output terminal of the IGBT 2-L is connected to the input terminal of the shunt 2. The output terminal of the shunt 2 is connected to the negative terminal of the high-voltage socket. The input terminal of the shunt 2 is connected to the input terminal of the operational amplifier 2. The output terminal of the operational amplifier 2 is connected to the high-voltage side MCU.

6. The control circuit combining PTC and compressor according to claim 5, characterized in that: There are two PTCs and two IGBTs. The output terminal of the IGBT driver 1 is connected to the G terminal of both IGBTs. The other end of each PTC is connected to the C terminal of each IGBT. The E terminal of each IGBT is connected to the input terminal of the shunt 1.

7. The control circuit combining PTC and compressor according to claim 5, characterized in that: The IGBT driver 2, compressor, IGBT2-H, IGBT2-L, shunt 2, and operational amplifier 2 are all in three units. The output terminal of each IGBT driver 2 is simultaneously connected to the G terminal of one IGBT2-H and the G terminal of one IGBT2-L. The E terminals of the three IGBT2-H are respectively connected to the C terminals of the three IGBT2-L. The C terminals of the three IGBT2-L are respectively connected to the three compressors. The E terminals of the three IGBT2-L are respectively connected to the input terminals of the three shunt 2. The voltage divider at the input terminals of the three shunt 2 is connected to the input terminals of the three operational amplifiers 2.

8. The control circuit combining PTC and compressor according to claim 1, characterized in that: The control circuit also includes a temperature acquisition circuit, which is connected to the low-voltage side MCU.

9. The control circuit combining PTC and compressor according to claim 8, characterized in that: The temperature acquisition circuit includes: a voltage divider resistor 2 and an NTC. A temperature acquisition power supply is connected to one end of the voltage divider resistor 2, the other end of the voltage divider resistor 2 is connected to one end of the NTC, the other end of the NTC is grounded, and one end of the NTC is connected to the low-voltage side MCU.

10. The control circuit combining PTC and compressor according to claim 8, characterized in that: There are three temperature acquisition circuits, and all three temperature acquisition circuits are connected to the low-voltage side MCU.

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