IGBT temperature maximum value sampling circuit and method

Abstract

According to the sampling circuit and method for the IGBT temperature maximum value, two identical temperature sampling sub-circuits are integrated, signal collection can be conducted on two independent temperature sampling resistors, on the basis that only one sampling circuit PCB area is occupied, only one MCU data processing port is needed, and the sampling circuit is simple in structure, convenient to use and high in sampling efficiency. Therefore, acquisition, analysis and signal output of two paths or even multiple paths of temperature signals can be realized, errors caused by interference caused by overlong-path transmission can be avoided by the simplified sampling circuit, and the acquisition precision of the maximum temperature signal is improved. Specifically, target parameter processing functions such as operational amplification, voltage comparison and minimum voltage output are integrated in each temperature sampling sub-circuit, so that a relatively small voltage signal (corresponding to a relatively high temperature) in the two temperature sampling sub-circuits can be screened out and output, and it is ensured that even under complex and changeable working conditions, the temperature of the temperature sampling sub-circuits can be accurately detected. And the highest temperature of the IGBT can be accurately captured, so that the use safety and reliability of the sampling circuit are improved.

Description

Technical Field

[0001] The present application relates to the technical field of circuit temperature data acquisition, and particularly to a sampling circuit and method for the maximum IGBT temperature. Background Art

[0002] To ensure the stable and reliable operation of an inverter, it is particularly important to accurately monitor the temperature of three-phase insulated gate bipolar transistors (IGBTs) in the inverter. The main purpose of this monitoring is to track the highest temperature point in the IGBT in real time to prevent equipment damage caused by overheating.

[0003] In the prior art, the following method is usually adopted to achieve this goal: Transmit the temperature signals of each IGBT to the microcontroller unit (MCU). The MCU is then responsible for comparing all the received temperature data to determine the maximum value among them. Once the highest temperature value exceeds the preset IGBT temperature protection threshold, the system will immediately activate the protection mechanism to shut down the inverter to avoid further damage.

[0004] For a three-phase system, at least three IGBT temperature acquisition points need to be set. And when IGBTs are used in parallel in each phase, in order to accurately monitor the temperature of each parallel IGBT, the number of required temperature acquisition points will increase accordingly. However, this approach brings two main problems: one is occupying more printed circuit board (PCB) area, and the other is increasing the processing burden and resource consumption of the MCU. Summary of the Invention

[0005] The present application provides a sampling circuit and method for the maximum IGBT temperature, which can reduce the PCB area occupation ratio of the temperature sampling circuit, and at the same time improve the convenience and accuracy of obtaining the maximum temperature among multiple monitored temperature data.

[0006] To solve the above technical problems, in the first aspect of the present application, a sampling circuit for the maximum IGBT temperature is disclosed. The sampling circuit includes at least two identical temperature sampling sub-circuits, denoted as the first temperature sampling sub-circuit and the second temperature sampling sub-circuit, where:

[0007] The first end of the first temperature sampling sub-circuit is used to be electrically connected to the first end of the first temperature sampling resistor; the first end of the second temperature sampling sub-circuit is used to be electrically connected to the first end of the second temperature sampling resistor;

[0008] The second end of the first temperature sampling sub-circuit and the second end of the second temperature sampling sub-circuit are both used to be electrically connected to the data interaction end of the MCU;

[0009] The sampling circuit is configured to perform a preset target parameter processing on the input parameters input to the sampling circuit based on the first temperature sampling sub-circuit and the second temperature sampling sub-circuit, and obtain a target parameter processing result corresponding to the input parameters; the input parameters at least include an input voltage; the target parameter processing includes operational amplification, voltage comparison, and minimum voltage output; the target parameter processing result includes a target voltage corresponding to the minimum voltage output.

[0010] The sampling circuit is further configured to transmit the target parameter processing result to the MCU, so as to parse the target parameter processing result through the MCU and obtain a target temperature corresponding to the target parameter processing result, where the target temperature is the maximum temperature corresponding to the sampling circuit.

[0011] As an optional implementation manner, in the first aspect of the present application, the input parameters further include an input current, and the target parameter processing result further includes a target current corresponding to the target voltage; and the sampling circuit further includes a voltage isolation sub-circuit, where:

[0012] The second ends of the first temperature sampling sub-circuit and the second temperature sampling sub-circuit are both electrically connected to the input end of the voltage isolation sub-circuit; the output end of the voltage isolation sub-circuit is used to be electrically connected to the data interaction end of the MCU.

[0013] The voltage isolation sub-circuit is configured to perform parameter isolation on the target parameter processing result and obtain a parameter isolation result corresponding to the target parameter processing result; the parameter isolation includes voltage regulation for the target voltage, current amplification for the target current, and signal isolation for target signals; the target signals include the target current and the target voltage.

[0014] The voltage isolation sub-circuit is further configured to transmit the parameter isolation result to the MCU, so as to parse the parameter isolation result through the MCU and obtain a target temperature corresponding to the parameter isolation result.

[0015] As an optional implementation manner, in the first aspect of the present application, the first temperature sampling sub-circuit includes a first operational amplifier module and a first temperature isolation module; the second temperature sampling sub-circuit includes a second operational amplifier module and a second temperature isolation module, where:

[0016] The first end of the first operational amplifier module is used to be electrically connected to the first end of the first temperature sampling resistor; the second end of the first operational amplifier module is used to be connected to the positive electrode of the power supply; the third end of the first operational amplifier module is used to be grounded; the fourth end of the first operational amplifier module is electrically connected to the first end of the first temperature isolation module; the fifth end of the first operational amplifier module is electrically connected to the second end of the first temperature isolation module;

[0017] The first end of the second operational amplifier module is used to be electrically connected to the first end of the second temperature sampling resistor; the second end of the second operational amplifier module is used to be connected to the positive electrode of the power supply; the third end of the second operational amplifier module is used to be grounded; the fourth end of the second operational amplifier module is electrically connected to the first end of the second temperature isolation module; the fifth end of the second operational amplifier module is electrically connected to the second end of the second temperature isolation module;

[0018] The third end of the first temperature isolation module and the third end of the second temperature isolation module are both electrically connected to the input end of the voltage isolation sub-circuit.

[0019] As an optional implementation, in the first aspect of the present application, the first operational amplifier module is used to perform target operational amplifier processing on a first input signal input into the first operational amplifier module, obtain a first operational amplifier processing result corresponding to the first input signal, and add the first operational amplifier processing result to a target parameter processing result corresponding to the input parameter;

[0020] The second operational amplifier module is used to perform the target operational amplifier processing on the second input signal input to the second operational amplifier module, obtain a second operational amplifier processing result corresponding to the second input signal, and add the second operational amplifier processing result to the target parameter processing result corresponding to the input parameter;

[0021] The target operational amplifier processing includes target sub-operations and operational amplification, and the target sub-operations include voltage division processing, filtering processing, and current limiting processing.

[0022] As an optional implementation, in the first aspect of the present application, the first operational amplifier processing result includes a first sub-operation result corresponding to the target sub-operation; the second operational amplifier processing result includes a second sub-operation result corresponding to the target sub-operation;

[0023] The first temperature isolation module is used to transmit a first current corresponding to the first voltage to the second temperature isolation module when the first voltage corresponding to the first sub-operation result is greater than the second voltage corresponding to the second sub-operation result, and is also used to cut off the signal transmission path corresponding to the third end of the first temperature isolation module and the data interaction end of the MCU;

[0024] The second temperature isolation module is configured to connect to the first current and cut off the signal transmission path corresponding to the fifth terminal of the second operational amplifier module and the second terminal of the second temperature isolation module when the first voltage is greater than the second voltage; and is further configured to transmit the second voltage to the MCU.

[0025] As an optional implementation manner, in the first aspect of the present application, the first operational amplifier module includes a first voltage-dividing resistor, a first filtering capacitor, a first current-limiting resistor, and a first operational amplifier; the second operational amplifier module includes a second voltage-dividing resistor, a second filtering capacitor, a second current-limiting resistor, and a second operational amplifier, where:

[0026] The first end of the first voltage-dividing resistor, the first end of the first filtering capacitor, and the first end of the first current-limiting resistor are all configured to be electrically connected to the first end of the first temperature sampling resistor; the second end of the first voltage-dividing resistor is configured to be connected to the positive pole of the power supply; the second end of the first filtering capacitor is configured to be grounded; the second end of the first current-limiting resistor is electrically connected to the non-inverting input terminal of the first operational amplifier;

[0027] The first end of the first operational amplifier is configured to be connected to the positive pole of the power supply; the second end of the first operational amplifier is configured to be grounded; the output terminal of the first operational amplifier is electrically connected to the first end of the first temperature isolation module; the inverting input terminal of the first operational amplifier is electrically connected to the second end of the first temperature isolation module;

[0028] The first end of the second voltage-dividing resistor, the first end of the second filtering capacitor, and the first end of the second current-limiting resistor are all configured to be electrically connected to the first end of the second temperature sampling resistor; the second end of the second voltage-dividing resistor is configured to be connected to the positive pole of the power supply; the second end of the second filtering capacitor is configured to be grounded; the second end of the second current-limiting resistor is electrically connected to the non-inverting input terminal of the second operational amplifier;

[0029] The first end of the second operational amplifier is configured to be connected to the positive pole of the power supply; the second end of the second operational amplifier is configured to be grounded; the output terminal of the second operational amplifier is electrically connected to the first end of the second temperature isolation module; the inverting input terminal of the second operational amplifier is electrically connected to the second end of the second temperature isolation module.

[0030] As an optional implementation manner, in the first aspect of the present application, the first temperature isolation module includes a first isolation diode, a second isolation diode, and a third current-limiting resistor; the second temperature isolation module includes a third isolation diode, a fourth isolation diode, and a fourth current-limiting resistor; where:

[0031] The output terminal of the first operational amplifier is electrically connected to the positive electrode of the first isolation diode and the negative electrode of the second isolation diode respectively; the negative electrode of the first isolation diode and the first end of the third current-limiting resistor are both electrically connected to the inverting input terminal of the first operational amplifier; the second end of the third current-limiting resistor and the positive electrode of the second isolation diode are both electrically connected to the input terminal of the voltage isolation sub-circuit;

[0032] The output terminal of the second operational amplifier is electrically connected to the positive electrode of the third isolation diode and the negative electrode of the fourth isolation diode respectively; the negative electrode of the third isolation diode and the first end of the fourth current-limiting resistor are both electrically connected to the inverting input terminal of the second operational amplifier; the second end of the fourth current-limiting resistor and the positive electrode of the fourth isolation diode are both used for electrical connection with the data interaction terminal of the MCU.

[0033] As an optional implementation manner, in the first aspect of the present application, the voltage isolation sub-circuit includes a first voltage isolation module, a target optocoupler, and a second voltage isolation module, where:

[0034] The second ends of the first temperature sampling sub-circuit and the second temperature sampling sub-circuit are both electrically connected to the input terminal of the first voltage isolation module; the first end of the first voltage isolation module is electrically connected to the first end of the target optocoupler;

[0035] The second end of the target optocoupler is electrically connected to the first end of the second voltage isolation module; the second end of the second voltage isolation module is used for electrical connection with the data interaction terminal of the MCU.

[0036] As an optional implementation manner, in the first aspect of the present application, the first voltage isolation module includes a fifth current-limiting resistor, a first triode, a second triode, a third voltage-dividing resistor, and a fourth voltage-dividing resistor, where:

[0037] The second ends of the first temperature sampling sub-circuit and the second temperature sampling sub-circuit are both electrically connected to the first end of the fifth current-limiting resistor; the second end of the fifth current-limiting resistor is electrically connected to the base of the first triode and the first end of the target optocoupler respectively;

[0038] The first end of the third voltage-dividing resistor and the second end of the target optocoupler are both used for connecting to the positive electrode of the power supply; the second end of the third voltage-dividing resistor is electrically connected to the emitter of the first triode and the base of the second triode respectively;

[0039] The collector of the second triode is electrically connected to the third end of the target optocoupler; the emitter of the second triode is electrically connected to the first end of the fourth voltage-dividing resistor;

[0040] The collector of the first triode, the second end of the fourth voltage-dividing resistor, and the fourth end of the target optocoupler are all used for grounding.

[0041] As an optional implementation manner, in the first aspect of the present application, the second voltage isolation module includes a sixth current-limiting resistor, a third triode, a fourth triode, a pull-up resistor, a first voltage-stabilizing resistor, and a second voltage-stabilizing resistor, where:

[0042] The fifth end of the target optocoupler is respectively electrically connected to the base of the third triode and the first end of the sixth current-limiting resistor; the first end of the first voltage-stabilizing resistor and the first end of the pull-up resistor are both used for accessing the positive pole of the power supply;

[0043] The second end of the sixth current-limiting resistor, the second end of the pull-up resistor, and the collector of the fourth triode are all used for electrically connecting to the data interaction terminal of the MCU;

[0044] The second end of the first voltage-stabilizing resistor is respectively electrically connected to the emitter of the third triode and the base of the fourth triode; the emitter of the fourth triode is electrically connected to the first end of the second voltage-stabilizing resistor;

[0045] The sixth end of the target optocoupler, the collector of the third triode, and the second end of the second voltage-stabilizing resistor are all used for grounding.

[0046] The second aspect of the present application discloses a method for sampling the maximum IGBT temperature. The sampling method is applied to a sampling circuit for the maximum IGBT temperature. The sampling circuit includes at least two identical temperature sampling sub-circuits, denoted as a first temperature sampling sub-circuit and a second temperature sampling sub-circuit, where:

[0047] The first end of the first temperature sampling sub-circuit is used for electrically connecting to the first end of a first temperature sampling resistor; the first end of the second temperature sampling sub-circuit is used for electrically connecting to the first end of a second temperature sampling resistor; the second end of the first temperature sampling sub-circuit and the second end of the second temperature sampling sub-circuit are both used for electrically connecting to the data interaction terminal of the MCU;

[0048] The method includes:

[0049] Based on the first temperature sampling sub-circuit and the second temperature sampling sub-circuit, the sampling circuit performs a preset target parameter processing on the input parameters input to the sampling circuit to obtain a target parameter processing result corresponding to the input parameters; the input parameters at least include an input voltage; the target parameter processing includes operational amplification, voltage comparison, and minimum voltage output; the target parameter processing result includes a target voltage corresponding to the minimum voltage output;

[0050] The sampling circuit transmits the target parameter processing result to the MCU, so that the MCU can analyze the target parameter processing result to obtain the target temperature corresponding to the target parameter processing result, and the target temperature is the maximum temperature corresponding to the sampling circuit.

[0051] As an alternative implementation, in the second aspect of the present application, the input parameter further includes an input current, and the target parameter processing result further includes a target current corresponding to the target voltage; and, the sampling circuit further includes a voltage isolation sub-circuit, where:

[0052] The second ends of the first temperature sampling sub-circuit and the second temperature sampling sub-circuit are both electrically connected to the input end of the voltage isolation sub-circuit; the output end of the voltage isolation sub-circuit is used to be electrically connected to the data interaction end of the MCU;

[0053] The method further includes:

[0054] The voltage isolation sub-circuit performs parameter isolation on the target parameter processing result to obtain a parameter isolation result corresponding to the target parameter processing result; the parameter isolation includes voltage regulation for the target voltage, current amplification for the target current, and signal isolation for the target signal; the target signal includes the target current and the target voltage;

[0055] The voltage isolation sub-circuit transmits the parameter isolation result to the MCU, so that the MCU can analyze the parameter isolation result to obtain the target temperature corresponding to the parameter isolation result.

[0056] As an alternative implementation, in the second aspect of the present application, the first temperature sampling sub-circuit includes a first operational amplifier module and a first temperature isolation module; the second temperature sampling sub-circuit includes a second operational amplifier module and a second temperature isolation module, where:

[0057] The first end of the first operational amplifier module is used to be electrically connected to the first end of the first temperature sampling resistor; the second end of the first operational amplifier module is used to connect to the positive pole of the power supply; the third end of the first operational amplifier module is used to be grounded; the fourth end of the first operational amplifier module is electrically connected to the first end of the first temperature isolation module; the fifth end of the first operational amplifier module is electrically connected to the second end of the first temperature isolation module;

[0058] The first end of the second operational amplifier module is used for electrically connecting to the first end of the second temperature sampling resistor; the second end of the second operational amplifier module is used for accessing the positive electrode of the power supply; the third end of the second operational amplifier module is used for grounding; the fourth end of the second operational amplifier module is electrically connected to the first end of the second temperature isolation module; the fifth end of the second operational amplifier module is electrically connected to the second end of the second temperature isolation module;

[0059] The third end of the first temperature isolation module and the third end of the second temperature isolation module are both electrically connected to the input end of the voltage isolation sub-circuit.

[0060] As an optional implementation manner, in the second aspect of the present application, the sampling circuit performs a preset target parameter processing on the input parameter input to the sampling circuit based on the first temperature sampling sub-circuit and the second temperature sampling sub-circuit, and obtains a target parameter processing result corresponding to the input parameter, including:

[0061] The first operational amplifier module performs a target operational amplifier processing on the first input signal input to the first operational amplifier module, obtains a first operational amplifier processing result corresponding to the first input signal, and adds the first operational amplifier processing result to the target parameter processing result corresponding to the input parameter;

[0062] The second operational amplifier module performs the target operational amplifier processing on the second input signal input to the second operational amplifier module, obtains a second operational amplifier processing result corresponding to the second input signal, and adds the second operational amplifier processing result to the target parameter processing result corresponding to the input parameter;

[0063] Wherein, the target operational amplifier processing includes target sub-operations and operational amplification, and the target sub-operations include voltage division processing, filtering processing, and current limiting processing.

[0064] As an optional implementation manner, in the second aspect of the present application, the first operational amplifier processing result includes a first sub-operation result corresponding to the target sub-operations; the second operational amplifier processing result includes a second sub-operation result corresponding to the target sub-operations;

[0065] The sampling circuit performs a preset target parameter processing on the input parameter input to the sampling circuit based on the first temperature sampling sub-circuit and the second temperature sampling sub-circuit, and obtains a target parameter processing result corresponding to the input parameter, further including:

[0066] When the first voltage corresponding to the first sub-operation result is greater than the second voltage corresponding to the second sub-operation result, the first temperature isolation module transmits the first current corresponding to the first voltage to the second temperature isolation module, and at the same time cuts off the signal transmission path between the third end of the first temperature isolation module and the data interaction end of the MCU;

[0067] When the first voltage is greater than the second voltage, the second temperature isolation module accesses the first current and cuts off the signal transmission path between the fifth end of the second operational amplifier module and the second end of the second temperature isolation module;

[0068] Moreover, the sampling circuit transmitting the target parameter processing result to the MCU includes:

[0069] The second temperature isolation module transmits the second voltage to the MCU.

[0070] As an optional implementation manner, in the second aspect of the present application, the first operational amplifier module includes a first voltage dividing resistor, a first filtering capacitor, a first current limiting resistor, and a first operational amplifier; the second operational amplifier module includes a second voltage dividing resistor, a second filtering capacitor, a second current limiting resistor, and a second operational amplifier, where:

[0071] The first end of the first voltage dividing resistor, the first end of the first filtering capacitor, and the first end of the first current limiting resistor are all used to be electrically connected to the first end of the first temperature sampling resistor; the second end of the first voltage dividing resistor is used to access the positive pole of the power supply; the second end of the first filtering capacitor is used to be grounded; the second end of the first current limiting resistor is electrically connected to the non-inverting input end of the first operational amplifier;

[0072] The first end of the first operational amplifier is used to access the positive pole of the power supply; the second end of the first operational amplifier is used to be grounded; the output end of the first operational amplifier is electrically connected to the first end of the first temperature isolation module; the inverting input end of the first operational amplifier is electrically connected to the second end of the first temperature isolation module;

[0073] The first end of the second voltage dividing resistor, the first end of the second filtering capacitor, and the first end of the second current limiting resistor are all used to be electrically connected to the first end of the second temperature sampling resistor; the second end of the second voltage dividing resistor is used to access the positive pole of the power supply; the second end of the second filtering capacitor is used to be grounded; the second end of the second current limiting resistor is electrically connected to the non-inverting input end of the second operational amplifier;

[0074] The first terminal of the second operational amplifier is used to connect to the positive pole of the power supply; the second terminal of the second operational amplifier is used to connect to the ground; the output terminal of the second operational amplifier is electrically connected to the first terminal of the second temperature isolation module; the inverting input terminal of the second operational amplifier is electrically connected to the second terminal of the second temperature isolation module.

[0075] As an optional implementation manner, in the second aspect of the present application, the first temperature isolation module includes a first isolation diode, a second isolation diode, and a third current limiting resistor; the second temperature isolation module includes a third isolation diode, a fourth isolation diode, and a fourth current limiting resistor; wherein:

[0076] The output terminal of the first operational amplifier is respectively electrically connected to the positive pole of the first isolation diode and the negative pole of the second isolation diode; the negative pole of the first isolation diode and the first terminal of the third current limiting resistor are both electrically connected to the inverting input terminal of the first operational amplifier; the second terminal of the third current limiting resistor and the positive pole of the second isolation diode are both electrically connected to the input terminal of the voltage isolation sub-circuit;

[0077] The output terminal of the second operational amplifier is respectively electrically connected to the positive pole of the third isolation diode and the negative pole of the fourth isolation diode; the negative pole of the third isolation diode and the first terminal of the fourth current limiting resistor are both electrically connected to the inverting input terminal of the second operational amplifier; the second terminal of the fourth current limiting resistor and the positive pole of the fourth isolation diode are both used to be electrically connected to the data interaction terminal of the MCU.

[0078] As an optional implementation manner, in the second aspect of the present application, the voltage isolation sub-circuit includes a first voltage isolation module, a target optocoupler, and a second voltage isolation module, wherein:

[0079] The second terminal of the first temperature sampling sub-circuit and the second terminal of the second temperature sampling sub-circuit are both electrically connected to the input terminal of the first voltage isolation module; the first terminal of the first voltage isolation module is electrically connected to the first terminal of the target optocoupler;

[0080] The second terminal of the target optocoupler is electrically connected to the first terminal of the second voltage isolation module; the second terminal of the second voltage isolation module is used to be electrically connected to the data interaction terminal of the MCU.

[0081] As an optional implementation manner, in the second aspect of the present application, the first voltage isolation module includes a fifth current limiting resistor, a first triode, a second triode, a third voltage dividing resistor, and a fourth voltage dividing resistor, wherein:

[0082] The second end of the first temperature sampling sub - circuit and the second end of the second temperature sampling sub - circuit are both electrically connected to the first end of the fifth current - limiting resistor; the second end of the fifth current - limiting resistor is respectively electrically connected to the base of the first triode and the first end of the target optocoupler;

[0083] The first end of the third voltage - dividing resistor and the second end of the target optocoupler are both used to connect to the positive pole of the power supply; the second end of the third voltage - dividing resistor is respectively electrically connected to the emitter of the first triode and the base of the second triode;

[0084] The collector of the second triode is electrically connected to the third end of the target optocoupler; the emitter of the second triode is electrically connected to the first end of the fourth voltage - dividing resistor;

[0085] The collector of the first triode, the second end of the fourth voltage - dividing resistor, and the fourth end of the target optocoupler are all used to be grounded.

[0086] As an optional implementation manner, in the second aspect of the present application, the second voltage isolation module includes a sixth current - limiting resistor, a third triode, a fourth triode, a pull - up resistor, a first voltage - stabilizing resistor, and a second voltage - stabilizing resistor, where:

[0087] The fifth end of the target optocoupler is respectively electrically connected to the base of the third triode and the first end of the sixth current - limiting resistor; the first end of the first voltage - stabilizing resistor and the first end of the pull - up resistor are both used to connect to the positive pole of the power supply;

[0088] The second end of the sixth current - limiting resistor, the second end of the pull - up resistor, and the collector of the fourth triode are all used to be electrically connected to the data interaction terminal of the MCU;

[0089] The second end of the first voltage - stabilizing resistor is respectively electrically connected to the emitter of the third triode and the base of the fourth triode; the emitter of the fourth triode is electrically connected to the first end of the second voltage - stabilizing resistor;

[0090] The sixth end of the target optocoupler, the collector of the third triode, and the second end of the second voltage - stabilizing resistor are all used to be grounded.

[0091] Compared with the prior art, the embodiments of the present application have the following beneficial effects:

[0092] In an embodiment of the present application, a sampling circuit for the maximum IGBT temperature is provided. The sampling circuit includes at least two identical temperature sampling sub - circuits, denoted as the first temperature sampling sub - circuit 10 and the second temperature sampling sub - circuit 20, where: The first end of the first temperature sampling sub - circuit 10 is used to be electrically connected to the first end of the first temperature sampling resistor; The first end of the second temperature sampling sub - circuit 20 is used to be electrically connected to the first end of the second temperature sampling resistor; The second ends of the first temperature sampling sub - circuit 10 and the second temperature sampling sub - circuit 20 are both used to be electrically connected to the data interaction end of the MCU; The sampling circuit is used to perform preset target parameter processing on the input parameters input to the sampling circuit based on the first temperature sampling sub - circuit 10 and the second temperature sampling sub - circuit 20, and obtain a target parameter processing result corresponding to the input parameters; The input parameters at least include the input voltage; The target parameter processing includes operational amplification, voltage comparison, and minimum voltage output; The target parameter processing result includes the target voltage corresponding to the minimum voltage output; The sampling circuit is further used to transmit the target parameter processing result to the MCU, so as to parse the target parameter processing result through the MCU to obtain the target temperature corresponding to the target parameter processing result, and the target temperature is the maximum temperature corresponding to the sampling circuit. It can be seen that by implementing the present application, by integrating two identical temperature sampling sub - circuits, signal acquisition can be performed on two independent temperature sampling resistors (or temperature signals corresponding to the temperature sampling resistors), so that on the basis of only occupying the PCB area of one sampling circuit, only one data processing port of the MCU is required to realize the acquisition and analysis of two - way or even multi - way temperature signals, and the direct output of the maximum temperature signal among two - way or even multi - way temperature signals can be realized through the hardware structure corresponding to the sampling circuit. Compared with the conventional temperature data acquisition using multiple circuits, the streamlined sampling circuit can avoid errors caused by interference brought by long - path transmission, thereby improving the acquisition accuracy of the maximum temperature signal. Specifically, by integrating target parameter processing functions such as operational amplification, voltage comparison, and minimum voltage output in each temperature sampling sub - circuit, the smaller voltage signal (corresponding to the higher temperature) among the two temperature sampling sub - circuits can be automatically selected and output to the MCU as the target voltage. This mechanism ensures that even under complex and variable working conditions, the highest temperature of the IGBT can be accurately captured, which is beneficial to improving the use stability, safety, and reliability of the sampling circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0093] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following described drawings are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0094] Figure 1 It is a schematic structural diagram of a sampling circuit for the maximum IGBT temperature disclosed in an embodiment of the present application;

[0095] Figure 2 It is a schematic structural diagram of another sampling circuit for the maximum IGBT temperature disclosed in an embodiment of the present application;

[0096] Figure 3 It is a schematic structural diagram of a temperature sampling sub - circuit in a sampling circuit for the maximum IGBT temperature disclosed in an embodiment of the present application;

[0097] Figure 4 It is a schematic structural diagram of a voltage isolation sub - circuit in a sampling circuit for the maximum IGBT temperature disclosed in an embodiment of the present application;

[0098] Figure 5 It is a schematic flow diagram of a sampling method for the maximum IGBT temperature disclosed in an embodiment of the present application;

[0099] Figure 6 It is a schematic flow diagram of another sampling method for the maximum IGBT temperature disclosed in an embodiment of the present application. Detailed implementation manners

[0100] In order to enable those skilled in the art to better understand the solution of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present application.

[0101] The terms "first", "second", etc. in the specification and claims of the present application and the above - mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non - exclusive inclusion. For example, a process, method, device, product or terminal that includes a series of steps or units is not limited to the listed steps or units, but may optionally further include steps or units not listed, or may optionally further include other steps or units inherent to these processes, methods, products or terminals.

[0102] Referring to "embodiment" in this article means that a specific feature, structure or characteristic described in combination with the embodiment may be included in at least one embodiment of the present application. The phrase appears in various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein may be combined with other embodiments.

[0103] The present application discloses a sampling circuit and method for the maximum IGBT temperature. By integrating two identical temperature sampling sub - circuits, it can collect signals from two independent temperature sampling resistors (or the temperature signals corresponding to the temperature sampling resistors), enabling the collection and analysis of two or even multiple temperature signals with only one MCU data - processing port while only occupying the PCB area of one sampling circuit. Moreover, it can directly output the maximum temperature signal among two or even multiple temperature signals through the corresponding hardware structure of the sampling circuit. Compared with the conventional temperature data acquisition using multiple circuits, this streamlined sampling circuit can avoid errors caused by interference from long - path transmission, thereby improving the acquisition accuracy of the maximum temperature signal. Specifically, by integrating functions such as operational amplification, voltage comparison, and minimum voltage output in each temperature sampling sub - circuit, it can automatically select the smaller voltage signal (corresponding to the higher temperature) from the two temperature sampling sub - circuits and output it as the target voltage to the MCU. This mechanism ensures that even under complex and variable working conditions, the highest temperature of the IGBT can be accurately captured, which is beneficial to improving the stability, safety, and reliability of the sampling circuit. The following will be described in detail respectively.

[0104] Embodiment 1

[0105] Please refer to Figure 1 , Figure 1 which is a schematic structural diagram of a sampling circuit for the maximum IGBT temperature disclosed in the embodiment of the present application. As Figure 1 shown, the sampling circuit for the maximum IGBT temperature may include at least two identical temperature sampling sub - circuits, denoted as the first temperature sampling sub - circuit 10 and the second temperature sampling sub - circuit 20, where:

[0106] The first end of the first temperature sampling sub - circuit 10 is used for electrically connecting to the first end of the first temperature sampling resistor; the first end of the second temperature sampling sub - circuit 20 is used for electrically connecting to the first end of the second temperature sampling resistor;

[0107] The second ends of the first temperature sampling sub - circuit 10 and the second temperature sampling sub - circuit 20 are both used for electrically connecting to the data interaction end of the MCU;

[0108] A sampling circuit for performing preset target parameter processing on the input parameters input to the sampling circuit based on the first temperature sampling sub - circuit 10 and the second temperature sampling sub - circuit 20 to obtain a target parameter processing result corresponding to the input parameters; the input parameters at least include input voltage; the target parameter processing includes operational amplification, voltage comparison, and minimum voltage output; the target parameter processing result includes a target voltage corresponding to the minimum voltage output;

[0109] The sampling circuit is also used to transmit the target parameter processing result to the MCU, so that the MCU can parse the target parameter processing result to obtain the target temperature corresponding to the target parameter processing result. The target temperature is the maximum temperature corresponding to the sampling circuit.

[0110] It can be seen that implementing Figure 1 the described sampling circuit for the maximum IGBT temperature can collect signals from two independent temperature sampling resistors (or temperature signals corresponding to the temperature sampling resistors) by integrating two identical temperature sampling sub-circuits. On the basis of only occupying the PCB area of one sampling circuit, only one data processing port of the MCU is required to realize the collection and analysis of two or more temperature signals, and the direct output of the maximum temperature signal among two or more temperature signals can be realized through the hardware structure corresponding to the sampling circuit. Compared with the conventional temperature data collection using multiple circuits, this streamlined sampling circuit can avoid errors caused by interference brought by long-path transmission, thereby improving the collection accuracy of the maximum temperature signal. Specifically, by integrating target parameter processing functions such as operational amplification, voltage comparison, and minimum voltage output in each temperature sampling sub-circuit, the smaller voltage signal (corresponding to the higher temperature) in the two temperature sampling sub-circuits can be automatically selected and output to the MCU as the target voltage. This mechanism ensures that even under complex and changeable working conditions, the highest temperature of the IGBT can be accurately captured, which is beneficial to improving the use stability, safety, and reliability of the sampling circuit.

[0111] In an alternative embodiment, the above input parameter further includes an input current, and the target parameter processing result further includes a target current corresponding to the target voltage.

[0112] Please refer to Figure 2 , Figure 2 which is a schematic structural diagram of another sampling circuit for the maximum IGBT temperature disclosed in the embodiments of the present application. As Figure 2 shown, the sampling circuit further includes a voltage isolation sub-circuit 30, where:

[0113] The second ends of the first temperature sampling sub-circuit 10 and the second temperature sampling sub-circuit 20 are both electrically connected to the input end of the voltage isolation sub-circuit 30; the output end of the voltage isolation sub-circuit 30 is used to be electrically connected to the data interaction end of the MCU;

[0114] The voltage isolation sub-circuit 30 is used to perform parameter isolation on the target parameter processing result to obtain a parameter isolation result corresponding to the target parameter processing result; the parameter isolation includes voltage regulation for the target voltage, current amplification for the target current, and signal isolation for the target signal; the target signal includes the target current and the target voltage;

[0115] The voltage isolation circuit 30 is also used to transmit the parameter isolation result to the MCU, so as to parse the parameter isolation result through the MCU to obtain the target temperature corresponding to the parameter isolation result.

[0116] It can be seen that in this optional embodiment, by simultaneously monitoring the input voltage and the input current, the working state of the IGBT can be more comprehensively reflected, which is beneficial to improving the accuracy of temperature monitoring; and, by introducing the voltage isolation circuit, voltage regulation for the target voltage, amplification for the target current, and signal isolation for the target signal are realized, effectively preventing the influence of electrical interference and noise on the monitoring data (parameter isolation result), thereby being beneficial to improving the accuracy and stability of data transmission; in addition, by combining the data parsing ability of the MCU, the target signal can be accurately parsed to obtain the target temperature, and the high-efficiency parsing speed of the target temperature provides data support for the maintenance and fault warning of the sampling circuit, which is beneficial to improving the operation and maintenance efficiency and practicality of the sampling circuit and its associated power system to a certain extent.

[0117] In another optional embodiment, as Figure 2 shown, the first temperature sampling sub-circuit 10 includes a first operational amplifier module 101 and a first temperature isolation module 102; the second temperature sampling sub-circuit 20 includes a second operational amplifier module 201 and a second temperature isolation module 202, where:

[0118] The first end of the first operational amplifier module 101 is used to be electrically connected to the first end of the first temperature sampling resistor; the second end of the first operational amplifier module 101 is used to access the positive pole of the power supply; the third end of the first operational amplifier module 101 is used to be grounded; the fourth end of the first operational amplifier module 101 is electrically connected to the first end of the first temperature isolation module 102; the fifth end of the first operational amplifier module 101 is electrically connected to the second end of the first temperature isolation module 102;

[0119] The first end of the second operational amplifier module 201 is used to be electrically connected to the first end of the second temperature sampling resistor; the second end of the second operational amplifier module 201 is used to access the positive pole of the power supply; the third end of the second operational amplifier module 201 is used to be grounded; the fourth end of the second operational amplifier module 201 is electrically connected to the first end of the second temperature isolation module 202; the fifth end of the second operational amplifier module 201 is electrically connected to the second end of the second temperature isolation module 202;

[0120] The third ends of the first temperature isolation module 102 and the second temperature isolation module 202 are both electrically connected to the input end of the voltage isolation circuit 30.

[0121] In this optional embodiment, it should be noted that the first operational amplifier module 101 is configured to perform target operational amplifier processing on a first input signal input to the first operational amplifier module 101 to obtain a first operational amplifier processing result corresponding to the first input signal, and add the first operational amplifier processing result to a target parameter processing result corresponding to an input parameter;

[0122] The second operational amplifier module 201 is configured to perform target operational amplifier processing on a second input signal input to the second operational amplifier module 201 to obtain a second operational amplifier processing result corresponding to the second input signal, and add the second operational amplifier processing result to a target parameter processing result corresponding to an input parameter;

[0123] Among them, the target operational amplifier processing includes target sub-operations and operational amplification, and the target sub-operations include voltage division processing, filtering processing, and current limiting processing.

[0124] It can be seen that in this optional embodiment, the sampling circuit of the maximum IGBT temperature is further refined. By introducing a target operational amplifier processing module (the first operational amplifier module and the second operational amplifier module) including voltage division processing, filtering processing, current limiting processing, and operational amplification, and combining with a temperature isolation module (the first temperature isolation module and the second temperature isolation module), high-precision processing and isolated transmission of the IGBT temperature monitoring signal (corresponding to the above parameter isolation result) are achieved, and the acquisition accuracy of the IGBT temperature monitoring signal is improved. Specifically, the first operational amplifier module and the second operational amplifier module effectively remove noise and interference in the signal by performing voltage division processing, filtering processing, and current limiting processing on the input signal, ensuring the purity and stability of the signal; at the same time, the operational amplification function further enhances the amplitude of the signal, making the temperature monitoring signal easier to process and analyze.

[0125] In this optional embodiment, further, the first operational amplifier processing result includes a first sub-operation result corresponding to the target sub-operation; the second operational amplifier processing result includes a second sub-operation result corresponding to the target sub-operation;

[0126] The first temperature isolation module 102 is configured to transmit a first current corresponding to the first voltage to the second temperature isolation module 202 when the first voltage corresponding to the first sub-operation result is greater than the second voltage corresponding to the second sub-operation result, and is also configured to cut off the signal transmission path between the third terminal of the first temperature isolation module 102 and the data interaction terminal of the MCU;

[0127] The second temperature isolation module 202 is configured to connect to the first current and cut off the signal transmission path between the fifth terminal of the second operational amplifier module 201 and the second terminal of the second temperature isolation module 202 when the first voltage is greater than the second voltage; and is also configured to transmit the second voltage to the MCU.

[0128] It can be seen that in this alternative embodiment, through the intelligent selection mechanism of the first temperature isolation module and the second temperature isolation module, the automatic recognition and priority transmission of the higher temperature signal (with a relatively lower voltage value) in the two temperature sampling channels are realized. Specifically, when the output voltage (the first voltage) of the first temperature sampling channel is higher than the output voltage (the second voltage) of the second temperature sampling channel, the first temperature isolation module not only transmits the corresponding first current to the second temperature isolation module, but also automatically cuts off the signal transmission path between the first temperature isolation module and the MCU. At the same time, after receiving the first current, the second temperature isolation module also cuts off the signal connection with the second operational amplifier module, ensuring that only the highest temperature signal (corresponding to the second voltage) is accurately and interference-free transmitted to the MCU, realizing the determination of the minimum voltage based on the hardware structure. Relatively speaking, combined with the characteristics of the temperature sampling resistor, this minimum voltage corresponds to the maximum temperature. Therefore, compared with the traditional and complex multi-channel temperature signal acquisition, this sampling circuit can realize the intelligent comparison and output of the maximum temperature signal through the hardware structure, which is beneficial to improving the accuracy and convenience of obtaining the maximum temperature.

[0129] In another alternative embodiment, please refer to Figure 3 , Figure 3 which is a schematic structural diagram of a temperature sampling sub-circuit in a sampling circuit for the maximum IGBT temperature disclosed in the embodiments of the present application. As Figure 3 shown, the first operational amplifier module 101 includes a first voltage-dividing resistor R1, a first filter capacitor C1, a first current-limiting resistor R2, and a first operational amplifier U1; the second operational amplifier module 201 includes a second voltage-dividing resistor R3, a second filter capacitor C2, a second current-limiting resistor R4, and a second operational amplifier U2, where:

[0130] The first end of the first voltage-dividing resistor R1, the first end of the first filter capacitor C1, and the first end of the first current-limiting resistor R2 are all used to be electrically connected to the first end of the first temperature sampling resistor; the second end of the first voltage-dividing resistor R1 is used to be connected to the positive pole of the power supply; the second end of the first filter capacitor C1 is used to be grounded; the second end of the first current-limiting resistor R2 is electrically connected to the non-inverting input terminal of the first operational amplifier U1;

[0131] The first end of the first operational amplifier U1 is used to be connected to the positive pole of the power supply; the second end of the first operational amplifier U1 is used to be grounded; the output terminal of the first operational amplifier U1 is electrically connected to the first end of the first temperature isolation module 102; the inverting input terminal of the first operational amplifier U1 is electrically connected to the second end of the first temperature isolation module 102;

[0132] The first end of the second voltage-dividing resistor R3, the first end of the second filtering capacitor C2, and the first end of the second current-limiting resistor R4 are all used for electrically connecting to the first end of the second temperature sampling resistor; the second end of the second voltage-dividing resistor R3 is used for connecting to the positive electrode of the power supply; the second end of the second filtering capacitor C2 is used for grounding; the second end of the second current-limiting resistor R4 is electrically connected to the non-inverting input terminal of the second operational amplifier U2;

[0133] The first end of the second operational amplifier U2 is used for connecting to the positive electrode of the power supply; the second end of the second operational amplifier U2 is used for grounding; the output terminal of the second operational amplifier U2 is electrically connected to the first end of the second temperature isolation module 202; the inverting input terminal of the second operational amplifier U2 is electrically connected to the second end of the second temperature isolation module 202.

[0134] It can be seen that in this optional embodiment, through the sub-components of the first operational amplifier module and the second operational amplifier module, voltage division processing, filtering processing, and current limiting processing can be performed on the input signal, effectively removing the noise and interference in the signal, ensuring the purity and stability of the signal; at the same time, the operational amplification function further enhances the amplitude of the signal, which is beneficial to improving the signal processing efficiency of the subsequently obtained temperature monitoring signal (corresponding to the above parameter isolation result) and reducing the signal analysis difficulty.

[0135] In this optional embodiment, as Figure 3 shown, the first temperature isolation module 102 includes a first isolation diode D1, a second isolation diode D2, and a third current-limiting resistor R5; the second temperature isolation module 202 includes a third isolation diode D3, a fourth isolation diode D4, and a fourth current-limiting resistor R6; wherein:

[0136] The output terminal of the first operational amplifier U1 is respectively electrically connected to the positive electrode of the first isolation diode D1 and the negative electrode of the second isolation diode D2; the negative electrode of the first isolation diode D1 and the first end of the third current-limiting resistor R5 are both electrically connected to the inverting input terminal of the first operational amplifier U1; the second end of the third current-limiting resistor R5 and the positive electrode of the second isolation diode D2 are both electrically connected to the input terminal of the voltage isolation sub-circuit 30;

[0137] The output terminal of the second operational amplifier U2 is respectively electrically connected to the positive electrode of the third isolation diode D3 and the negative electrode of the fourth isolation diode D4; the negative electrode of the third isolation diode D3 and the first end of the fourth current-limiting resistor R6 are both electrically connected to the inverting input terminal of the second operational amplifier U2; the second end of the fourth current-limiting resistor R6 and the positive electrode of the fourth isolation diode D4 are both electrically connected to the input terminal of the voltage isolation sub-circuit 30.

[0138] In this optional embodiment, for Figure 3The specific circuit principle of the temperature sampling sub-circuit corresponding to the one that can output the target voltage from the first temperature sampling sub-circuit 10 and the second temperature sampling sub-circuit 20 is described as follows:

[0139] Suppose Figure 3 In the left first temperature sampling sub-circuit 10, the voltage of the 3rd pin of the operational amplifier U1 is V3, and the voltage of the 1st pin is V1; and, in the right second temperature sampling sub-circuit 20, the voltage of the 5th pin of the second operational amplifier U2 is V5, the voltage of the 6th pin is V6, and the voltage of the 7th pin is V7; and, suppose the voltage drops of the first diode D1, the second diode D2 in the first temperature sampling sub-circuit 10, the third diode D3, and the fourth diode D4 in the second temperature sampling sub-circuit 20 are all Vpn, and the minimum value of V3 and V5 is VNTCmax, the first temperature sampling resistor is NTC1, and the second temperature sampling resistor is NTC2.

[0140] Specifically, first assume that both the first operational amplifier U1 and the second operational amplifier U2 are in the normal amplification state, then V1 = V3 + Vpn, V7 = V5 + Vpn. If V3 > V5, then V1 > V7. There is a current at the output end of the first operational amplifier U1 passing through the upper end of D1, R5, flowing to the lower end of D4, and finally returning to the second operational amplifier U2. At this time, the lower end of D2 is not conducting, and the lower end of D4 is conducting. And since the upper end of D3 is not conducting, so V7 = V5 + Vpn does not hold. And because the upper end of D3 is cut off, there is no current on R6. Therefore, the voltages at both ends of R6 are equal, that is, VNTCmax = V6. The voltages at the positive and negative ends of the second operational amplifier U2 are equal, so V6 = V5, that is, VNTCmax = V5, corresponding to the maximum temperature of NTC2. Vice versa (this refers to the other case where V3 < V5, and the above reasoning process remains the same, and the result is adjusted to output the maximum temperature of NTC1).

[0141] Based on the above description, similarly, when the temperature sampling sub-module in the sampling circuit is extended to multiple, the above principle still holds. For example, the number of the temperature sampling sub-modules can be extended to 6, and the 6 temperature sampling sub-modules adopt the Figure 3 corresponding circuit connection relationship, then through a structure similar to that in the Figure 3 , it can automatically compare the magnitudes of the voltages at six points of NTC1 - NTC6 (the 6 temperature sampling sub-modules), and take the minimum value of the voltages at the 6 points as the voltage output at the NTCMAX point. That is, it realizes comparing the monitored temperature data of the six-way temperature sampling sub-modules simultaneously and outputting the corresponding maximum temperature.

[0142] It can be seen that in this alternative embodiment, through the intelligent selection mechanism of the first temperature isolation module and the second temperature isolation module, the automatic recognition and priority transmission of the higher temperature signal (with a relatively lower voltage value) in the two temperature sampling channels are realized, further improving the accuracy and convenience of obtaining the maximum temperature.

[0143] In another alternative embodiment, as Figure 2 shown, the voltage isolation sub-circuit 30 includes a first voltage isolation module 301, a target optocoupler U3, and a second voltage isolation module 302, where:

[0144] The second ends of the first temperature sampling sub-circuit 10 and the second temperature sampling sub-circuit 20 are both electrically connected to the input end of the first voltage isolation module 301; the first end of the first voltage isolation module 301 is electrically connected to the first end of the target optocoupler U3;

[0145] The second end of the target optocoupler U3 is electrically connected to the first end of the second voltage isolation module 302; the second end of the second voltage isolation module 302 is used to be electrically connected to the data interaction end of the MCU.

[0146] In this alternative embodiment, further, please refer to Figure 4 , Figure 4 which is a schematic structural diagram of the voltage isolation sub-circuit in a sampling circuit for the maximum IGBT temperature disclosed in the embodiments of the present application. As Figure 4 shown, the first voltage isolation module 301 includes a fifth current-limiting resistor R7, a first triode Q1, a second triode Q2, a third voltage-dividing resistor R8, and a fourth voltage-dividing resistor R9, where:

[0147] The second ends of the first temperature sampling sub-circuit 10 and the second temperature sampling sub-circuit 20 are both electrically connected to the first end of the fifth current-limiting resistor R7; the second end of the fifth current-limiting resistor R7 is respectively electrically connected to the base of the first triode Q1 and the first end of the target optocoupler U3;

[0148] The first end of the third voltage-dividing resistor R8 and the second end of the target optocoupler U3 are both used to connect to the positive pole of the power supply; the second end of the third voltage-dividing resistor R8 is respectively electrically connected to the emitter of the first triode Q1 and the base of the second triode Q2;

[0149] The collector of the second triode Q2 is electrically connected to the third end of the target optocoupler U3; the emitter of the second triode Q2 is electrically connected to the first end of the fourth voltage-dividing resistor R9;

[0150] The collector of the first triode Q1, the second end of the fourth voltage-dividing resistor R9, and the fourth end of the target optocoupler U3 are all used to be grounded.

[0151] In this alternative embodiment, further, asFigure 4 As shown, the second voltage isolation module 302 includes a sixth current-limiting resistor R10, a third triode Q3, a fourth triode Q4, a pull-up resistor R11, a first voltage-regulating resistor R12, and a second voltage-regulating resistor R13, where:

[0152] The fifth terminal of the target optocoupler U3 is electrically connected to the base of the third triode Q3 and the first terminal of the sixth current-limiting resistor R10 respectively; the first terminals of the first voltage-regulating resistor R12 and the pull-up resistor R11 are both used to connect to the positive pole of the power supply;

[0153] The second terminal of the sixth current-limiting resistor R10, the second terminal of the pull-up resistor R11, and the collector of the fourth triode Q4 are all used to be electrically connected to the data interaction terminal of the MCU;

[0154] The second terminal of the first voltage-regulating resistor R12 is electrically connected to the emitter of the third triode Q3 and the base of the fourth triode Q4 respectively; the emitter of the fourth triode Q4 is electrically connected to the first terminal of the second voltage-regulating resistor R13;

[0155] The sixth terminal of the target optocoupler U3, the collector of the third triode Q3, and the second terminal of the second voltage-regulating resistor R13 are all used to be grounded.

[0156] In this optional embodiment, R7 and R10 are current-limiting resistors, which play a role in adjusting the relationship between the input and output voltages. Moreover, in this voltage isolation sub-circuit, there is a voltage ratio relationship, specifically:

[0157]

[0158] In this optional embodiment, the first triode Q1 and the second triode Q2 play a role in amplifying the current, so that the light-emitting diodes corresponding to pins 1 and 2 in the target optocoupler U3 can work normally.

[0159] In this optional embodiment, R8 and R9 are voltage-dividing resistors, enabling the first triode Q1 and the second triode Q2 to work in the amplification region.

[0160] In this optional embodiment, the target optocoupler U3 is a linear optocoupler. Among them, the diodes corresponding to pins 1 and 2 are light-emitting diodes, and the diodes corresponding to pins 3, 4 and 5, 6 are all photosensitive diodes. After they receive the light from the diodes at pins 1 and 2, they will generate current, and the current flowing through pins 3 and 4 is equal to the current flowing through pins 5 and 6.

[0161] In this optional embodiment, the resistor R11 is an output pull-up resistor, ensuring that sufficient current can be provided when the load is too large and the output voltage will not be pulled down; the third triode Q3 and the fourth triode Q4 play a role in current amplification.

[0162] In this alternative embodiment, R12 and R13 enable the third triode Q3 and the fourth triode Q4 to operate in the amplification region, ensuring the normal operation of the amplified current. Further, the amplified current formed by the third triode Q3, the fourth triode Q4, R12, and R13 can ensure that when there is no input from the NTC MAX on the left side of R7, the output voltage of the NTC MAX ADC is 0V.

[0163] In this alternative embodiment, for Figure 4 the basic principle of the corresponding voltage isolation sub-circuit 30 is as follows:

[0164] Assume that the current flowing through pins 1 and 2 of the target optocoupler U3 is I 12 , the current flowing through pins 3 and 4 of the target optocoupler U3 is I 34 , and the current flowing through pins 6 and 5 of the target optocoupler U3 is I 65 . The base currents of Q1 and Q3 are relatively small and can be ignored. And then the following relationships exist among the currents of these three optocouplers:

[0165] I 34 = k1 * I 12

[0166] I 65 = k2 * I 12

[0167] And the input voltage and output voltage of this voltage isolation sub-circuit 30 have the following relationships:

[0168] V NTCMAX = k1 * I 12 * R 214

[0169] V NTCMAX_ADC = k2 * I 12 * R 213

[0170] Therefore

[0171]

[0172] Among them, the above k1 and k2 are linear coupling coefficients corresponding to the coupling coefficient of the target optocoupler U3 itself.

[0173] It can be seen that in this alternative embodiment, by introducing a voltage isolation sub-circuit and based on the detailed structure of this voltage isolation sub-circuit, voltage regulation for the target voltage, amplification for the target current, and signal isolation for the target signal are achieved, effectively preventing the influence of electrical interference and noise on the monitoring data (parameter isolation result). Thus, it is beneficial to improve the accuracy and stability of data transmission, and it is also beneficial to improve the practicability and reliability of this sampling circuit.

[0174] Embodiment 2

[0175] Please refer to Figure 5 , Figure 5 , which is a schematic flowchart of a sampling method for the maximum IGBT temperature disclosed in the embodiments of the present application. Among them, Figure 5 The described sampling method for the maximum IGBT temperature can be applied to the sampling circuit for the maximum IGBT temperature, and the embodiments of the present application do not make any limitations. For the circuit structure corresponding to the sampling circuit for the maximum IGBT temperature, please refer to the relevant descriptions in Embodiment 1, and the embodiments of the present application will not elaborate. And, as Figure 5 shown, the sampling method for the maximum IGBT temperature may include the following operations:

[0176] 401. The sampling circuit performs preset target parameter processing on the input parameters input to the sampling circuit based on the first temperature sampling sub-circuit and the second temperature sampling sub-circuit, and obtains a target parameter processing result corresponding to the input parameters.

[0177] In the embodiments of the present application, the input parameters at least include the input voltage; the target parameter processing includes operational amplification, voltage comparison, and minimum voltage output; the target parameter processing result includes the target voltage corresponding to the minimum voltage output.

[0178] 402. The sampling circuit transmits the target parameter processing result to the MCU, so that the MCU analyzes the target parameter processing result to obtain the target temperature corresponding to the target parameter processing result, and the target temperature is the maximum temperature corresponding to the sampling circuit.

[0179] It can be seen that the implemented Figure 1 The sampling circuit for the maximum IGBT temperature, by integrating two identical temperature sampling sub-circuits, can collect signals from two independent temperature sampling resistors (or temperature signals corresponding to the temperature sampling resistor), so that on the basis of only occupying the PCB area of one sampling circuit, only one data processing port of the MCU is required to realize the acquisition and analysis of two or more temperature signals, and the direct output of the maximum temperature signal among two or more temperature signals can be realized through the hardware structure corresponding to the sampling circuit. Compared with the conventional temperature data acquisition using multiple circuits, this simplified sampling circuit can avoid errors caused by interference brought by long-path transmission, thereby improving the acquisition accuracy of the maximum temperature signal. Specifically, by integrating functions such as operational amplification, voltage comparison, and minimum voltage output in each temperature sampling sub-circuit, the smaller voltage signal (corresponding to the higher temperature) in the two temperature sampling sub-circuits can be automatically selected and output to the MCU as the target voltage. This mechanism ensures that even under complex and variable working conditions, the highest temperature of the IGBT can be accurately captured, which is beneficial to improving the use stability, safety, and reliability of the sampling circuit.

[0180] In an alternative embodiment, the above step 401 is specifically implemented by the sampling circuit based on the first temperature sampling sub-circuit and the second temperature sampling sub-circuit to perform a preset target parameter processing on the input parameters input to the sampling circuit, and obtain a target parameter processing result corresponding to the input parameters, which specifically includes:

[0181] The first operational amplifier module performs a target operational amplification process on the first input signal input to the first operational amplifier module to obtain a first operational amplification result corresponding to the first input signal, and adds the first operational amplification result to the target parameter processing result corresponding to the input parameters;

[0182] The second operational amplifier module performs a target operational amplification process on the second input signal input to the second operational amplifier module to obtain a second operational amplification result corresponding to the second input signal, and adds the second operational amplification result to the target parameter processing result corresponding to the input parameters;

[0183] Wherein, the target operational amplification process includes target sub-operations and operational amplification, and the target sub-operations include voltage division processing, filtering processing, and current limiting processing.

[0184] It can be seen that in this alternative embodiment, by introducing a target operational amplification processing module (the first operational amplifier module and the second operational amplifier module) including voltage division processing, filtering processing, current limiting processing, and operational amplification, and combining with a temperature isolation module (the first temperature isolation module and the second temperature isolation module), high-precision processing and isolated transmission of the IGBT temperature monitoring signal (corresponding to the above parameter isolation result) are realized, and the acquisition accuracy of the IGBT temperature monitoring signal is improved. Specifically, the first operational amplifier module and the second operational amplifier module effectively remove noise and interference in the signal through voltage division processing, filtering processing, and current limiting processing on the input signal, ensuring the purity and stability of the signal; at the same time, the operational amplification function further enhances the amplitude of the signal, making the temperature monitoring signal easier to process and analyze.

[0185] In another alternative embodiment, the first operational amplification result includes a first sub-operation result corresponding to the target sub-operation; the second operational amplification result includes a second sub-operation result corresponding to the target sub-operation;

[0186] The above step 401 is specifically further implemented by the sampling circuit based on the first temperature sampling sub-circuit and the second temperature sampling sub-circuit to perform a preset target parameter processing on the input parameters input to the sampling circuit, and obtain a target parameter processing result corresponding to the input parameters, which specifically further includes:

[0187] When the first voltage corresponding to the first sub-operation result is greater than the second voltage corresponding to the second sub-operation result, the first temperature isolation module transmits the first current corresponding to the first voltage to the second temperature isolation module, and at the same time cuts off the signal transmission path between the third end of the first temperature isolation module and the data interaction end of the MCU;

[0188] When the first voltage is greater than the second voltage, the second temperature isolation module accesses the first current and cuts off the signal transmission path between the fifth end of the second operational amplifier module and the second end of the second temperature isolation module;

[0189] Moreover, the specific manner in which the sampling circuit transmits the target parameter processing result to the MCU in step 402 above includes:

[0190] The second temperature isolation module transmits the second voltage to the MCU.

[0191] It can be seen that in this optional embodiment, through the intelligent selection mechanism of the first temperature isolation module and the second temperature isolation module, automatic identification and priority transmission of the higher temperature signal (with a relatively lower voltage value) in the two temperature sampling channels are achieved. Specifically, when the output voltage (first voltage) of the first temperature sampling channel is higher than the output voltage (second voltage) of the second temperature sampling channel, the first temperature isolation module not only transmits the corresponding first current to the second temperature isolation module, but also automatically cuts off the signal transmission path between the first temperature isolation module and the MCU. At the same time, after receiving the first current, the second temperature isolation module also cuts off the signal connection with the second operational amplifier module, ensuring that only the highest temperature signal (corresponding to the second voltage) is accurately and interference-free transmitted to the MCU, realizing the determination of the minimum voltage based on the hardware structure. Relatively speaking, combined with the characteristics of the temperature sampling resistor, this minimum voltage corresponds to the maximum temperature; therefore, compared with the traditional and complex multi-channel temperature signal acquisition, this sampling circuit can realize the intelligent comparison and output of the maximum temperature signal through the hardware structure, which is beneficial to improving the accuracy and convenience of obtaining the maximum temperature.

[0192] Embodiment Three

[0193] Please refer to Figure 6 , Figure 6 which is a schematic flowchart of another sampling circuit for the maximum IGBT temperature disclosed in the embodiments of the present application. Among them, Figure 6 The described sampling circuit for the maximum IGBT temperature can be applied to the sampling circuit for the maximum IGBT temperature, and the embodiments of the present application do not make any limitations. For the circuit structure corresponding to this sampling circuit for the maximum IGBT temperature, please refer to the relevant descriptions in Embodiment One, and the embodiments of the present application will not be elaborated. Moreover, as Figure 6 shown, this sampling circuit for the maximum IGBT temperature can include the following operations:

[0194] 501. The sampling circuit performs preset target parameter processing on the input parameters input to the sampling circuit based on the first temperature sampling sub-circuit and the second temperature sampling sub-circuit, and obtains a target parameter processing result corresponding to the input parameters.

[0195] In the embodiments of the present application, the input parameters further include an input current, the target parameter processing result further includes a target current corresponding to a target voltage; and the sampling circuit further includes a voltage isolation sub-circuit.

[0196] 502. The voltage isolation sub-circuit performs parameter isolation on the target parameter processing result to obtain a parameter isolation result corresponding to the target parameter processing result.

[0197] In the embodiments of the present application, the parameter isolation includes voltage regulation for the target voltage, current amplification for the target current, and signal isolation for the target signal; the target signal includes the target current and the target voltage.

[0198] 503. The voltage isolation sub-circuit transmits the parameter isolation result to the MCU, so that the MCU analyzes the parameter isolation result to obtain a target temperature corresponding to the parameter isolation result.

[0199] In the embodiments of the present application, for other descriptions of step 501, please refer to the specific descriptions of step 401 in Embodiment 2, and the embodiments of the present application will not be elaborated here.

[0200] It can be seen that the Figure 6 sampling circuit for the maximum IGBT temperature described can more comprehensively reflect the working state of the IGBT by simultaneously monitoring the input voltage and input current, which is beneficial to improving the accuracy of temperature monitoring; and by introducing a voltage isolation sub-circuit, voltage regulation for the target voltage, amplification of the target current, and signal isolation for the target signal are realized, effectively preventing the influence of electrical interference and noise on the monitoring data (parameter isolation result), thereby being beneficial to improving the accuracy and stability of data transmission; in addition, it can combine the data analysis ability of the MCU to accurately analyze the target signal to obtain the target temperature, and the high-efficiency analysis speed of the target temperature provides data support for the maintenance and fault warning of the sampling circuit, which is beneficial to improving the operation and maintenance efficiency and practicality of the sampling circuit and its associated power system to a certain extent.

[0201] Finally, it should be noted that what is disclosed by a sampling circuit and method for the maximum IGBT temperature in the embodiments of the present application is only the preferred embodiments of the present application, which are only used to illustrate the technical solutions of the present application and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A sampling circuit for the maximum temperature of an IGBT, characterized in that: The sampling circuit includes at least two identical temperature sampling subcircuits, which are denoted as a first temperature sampling subcircuit and a second temperature sampling subcircuit, wherein: The first end of the first temperature sampling subcircuit is used to be electrically connected to the first end of the first temperature sampling resistor; the first end of the second temperature sampling subcircuit is used to be electrically connected to the first end of the second temperature sampling resistor; The second end of the first temperature sampling subcircuit and the second end of the second temperature sampling subcircuit are both used to be electrically connected to the data interaction end of the MCU; The sampling circuit is used to perform preset target parameter processing on input parameters input to the sampling circuit based on the first temperature sampling subcircuit and the second temperature sampling subcircuit to obtain a target parameter processing result corresponding to the input parameter; the input parameter at least includes an input voltage; the target parameter processing includes operational amplification, voltage comparison and minimum voltage output; the target parameter processing result includes a target voltage corresponding to the minimum voltage output; The sampling circuit is also used to transmit the target parameter processing result to the MCU, so that the target parameter processing result is analyzed by the MCU to obtain a target temperature corresponding to the target parameter processing result, and the target temperature is a maximum value temperature corresponding to the sampling circuit.

2. The IGBT temperature maximum value sampling circuit according to claim 1, characterized in that: The input parameter further includes an input current, and the target parameter processing result further includes a target current corresponding to the target voltage; and the sampling circuit further includes a voltage isolation subcircuit, wherein: The second end of the first temperature sampling subcircuit and the second end of the second temperature sampling subcircuit are both electrically connected to the input end of the voltage isolation subcircuit; the output end of the voltage isolation subcircuit is used to be electrically connected to the data interaction end of the MCU; The voltage isolation subcircuit is used to perform parameter isolation on the target parameter processing result to obtain a parameter isolation result corresponding to the target parameter processing result; the parameter isolation includes voltage regulation for the target voltage, current amplification for the target current, and signal isolation for the target signal; the target signal includes the target current and the target voltage; The voltage isolation sub-circuit is further used to transmit the parameter isolation result to the MCU, so that the parameter isolation result is analyzed by the MCU to obtain a target temperature corresponding to the parameter isolation result.

3. The IGBT temperature maximum value sampling circuit according to claim 2, characterized in that: The first temperature sampling subcircuit includes a first operational amplifier module and a first temperature isolation module; the second temperature sampling subcircuit includes a second operational amplifier module and a second temperature isolation module, wherein: The first end of the first operational amplifier module is used to be electrically connected to the first end of the first temperature sampling resistor; the second end of the first operational amplifier module is used to be connected to the positive electrode of the power supply; the third end of the first operational amplifier module is used to be grounded; the fourth end of the first operational amplifier module is electrically connected to the first end of the first temperature isolation module; the fifth end of the first operational amplifier module is electrically connected to the second end of the first temperature isolation module; The first end of the second operational amplifier module is used to be electrically connected to the first end of the second temperature sampling resistor; the second end of the second operational amplifier module is used to be connected to the positive electrode of the power supply; the third end of the second operational amplifier module is used to be grounded; the fourth end of the second operational amplifier module is electrically connected to the first end of the second temperature isolation module; the fifth end of the second operational amplifier module is electrically connected to the second end of the second temperature isolation module; The third end of the first temperature isolation module and the third end of the second temperature isolation module are both electrically connected to the input end of the voltage isolation sub-circuit.

4. The IGBT maximum temperature sampling circuit according to claim 3, characterized in that: The first operational amplifier module is used to perform target operational amplifier processing on a first input signal input to the first operational amplifier module, obtain a first operational amplifier processing result corresponding to the first input signal, and add the first operational amplifier processing result to a target parameter processing result corresponding to the input parameter; The second operational amplifier module is used to perform the target operational amplifier processing on the second input signal input to the second operational amplifier module, obtain a second operational amplifier processing result corresponding to the second input signal, and add the second operational amplifier processing result to the target parameter processing result corresponding to the input parameter; The target operational amplifier processing includes target sub-operations and operational amplification, and the target sub-operations include voltage division processing, filtering processing, and current limiting processing.

5. The IGBT maximum temperature sampling circuit according to claim 4, characterized in that: The first operation amplifier processing result includes a first sub-operation result corresponding to the target sub-operation; the second operation amplifier processing result includes a second sub-operation result corresponding to the target sub-operation; The first temperature isolation module is used to transmit a first current corresponding to the first voltage to the second temperature isolation module when the first voltage corresponding to the first sub-operation result is greater than the second voltage corresponding to the second sub-operation result, and is also used to cut off the signal transmission path corresponding to the third end of the first temperature isolation module and the data interaction end of the MCU; The second temperature isolation module is used to connect the first current and isolate the signal transmission path corresponding to the fifth end of the second operational amplifier module and the second end of the second temperature isolation module when the first voltage is greater than the second voltage; and is also used to transmit the second voltage to the MCU.

6. The IGBT temperature maximum value sampling circuit according to claim 4 or 5, characterized in that: The first operational amplifier module includes a first voltage-dividing resistor, a first filter capacitor, a first current-limiting resistor, and a first operational amplifier; the second operational amplifier module includes a second voltage-dividing resistor, a second filter capacitor, a second current-limiting resistor, and a second operational amplifier, wherein: The first end of the first voltage-dividing resistor, the first end of the first filter capacitor, and the first end of the first current-limiting resistor are all used to be electrically connected to the first end of the first temperature sampling resistor; the second end of the first voltage-dividing resistor is used to be connected to the positive electrode of the power supply; the second end of the first filter capacitor is used to be grounded; the second end of the first current-limiting resistor is electrically connected to the same-direction input end of the first operational amplifier; The first end of the first operational amplifier is used to connect to the positive electrode of the power supply; the second end of the first operational amplifier is used to be grounded; the output end of the first operational amplifier is electrically connected to the first end of the first temperature isolation module; the reverse input end of the first operational amplifier is electrically connected to the second end of the first temperature isolation module; The first end of the second voltage-dividing resistor, the first end of the second filter capacitor, and the first end of the second current-limiting resistor are all used to be electrically connected to the first end of the second temperature sampling resistor; the second end of the second voltage-dividing resistor is used to be connected to the positive electrode of the power supply; the second end of the second filter capacitor is used to be grounded; the second end of the second current-limiting resistor is electrically connected to the same-direction input end of the second operational amplifier; The first end of the second operational amplifier is used to connect to the positive pole of the power supply; the second end of the second operational amplifier is used to be grounded; the output end of the second operational amplifier is electrically connected to the first end of the second temperature isolation module; the reverse input end of the second operational amplifier is electrically connected to the second end of the second temperature isolation module.

7. The IGBT temperature maximum value sampling circuit according to claim 6, characterized in that: The first temperature isolation module includes a first isolation diode, a second isolation diode and a third current limiting resistor; the second temperature isolation module includes a third isolation diode, a fourth isolation diode and a fourth current limiting resistor; wherein: The output end of the first operational amplifier is electrically connected to the anode of the first isolation diode and the cathode of the second isolation diode respectively; the cathode of the first isolation diode and the first end of the third current limiting resistor are electrically connected to the reverse input end of the first operational amplifier; the second end of the third current limiting resistor and the anode of the second isolation diode are electrically connected to the input end of the voltage isolation sub-circuit; The output end of the second operational amplifier is electrically connected to the anode of the third isolation diode and the cathode of the fourth isolation diode, respectively; the cathode of the third isolation diode and the first end of the fourth current limiting resistor are electrically connected to the reverse input end of the second operational amplifier; the second end of the fourth current limiting resistor and the anode of the fourth isolation diode are used to be electrically connected to the data interaction end of the MCU.

8. The IGBT temperature maximum value sampling circuit according to claim 2, characterized in that: The voltage isolation subcircuit comprises a first voltage isolation module, a target optical coupler and a second voltage isolation module, wherein: The second end of the first temperature sampling subcircuit and the second end of the second temperature sampling subcircuit are both electrically connected to the input end of the first voltage isolation module; the first end of the first voltage isolation module is electrically connected to the first end of the target optical coupler; The second end of the target optocoupler is electrically connected to the first end of the second voltage isolation module; the second end of the second voltage isolation module is used to be electrically connected to the data interaction end of the MCU.

9. The sampling circuit for the maximum IGBT temperature according to claim 8, characterized in that: The first voltage isolation module includes a fifth current limiting resistor, a first transistor, a second transistor, a third voltage dividing resistor, and a fourth voltage dividing resistor, wherein: The second end of the first temperature sampling subcircuit and the second end of the second temperature sampling subcircuit are both electrically connected to the first end of the fifth current limiting resistor; the second end of the fifth current limiting resistor is electrically connected to the base of the first transistor and the first end of the target optocoupler respectively; The first end of the third voltage-dividing resistor and the second end of the target optical coupler are both used to connect to the positive electrode of the power supply; the second end of the third voltage-dividing resistor is electrically connected to the emitter of the first transistor and the base of the second transistor respectively; The collector of the second transistor is electrically connected to the third end of the target optical coupler; the emitter of the second transistor is electrically connected to the first end of the fourth voltage-dividing resistor; The collector of the first transistor, the second end of the fourth voltage-dividing resistor, and the fourth end of the target optical coupler are all grounded.

10. The IGBT temperature maximum value sampling circuit according to claim 9, characterized in that: The second voltage isolation module includes a sixth current limiting resistor, a third transistor, a fourth transistor, a pull-up resistor, a first voltage stabilizing resistor and a second voltage stabilizing resistor, wherein: The fifth end of the target optical coupler is electrically connected to the base of the third transistor and the first end of the sixth current limiting resistor respectively; the first end of the first voltage-stabilizing resistor and the first end of the pull-up resistor are both used to connect to the positive electrode of the power supply; The second end of the sixth current limiting resistor, the second end of the pull-up resistor, and the collector of the fourth transistor are all used to be electrically connected to the data interaction terminal of the MCU; The second end of the first voltage-stabilizing resistor is electrically connected to the emitter of the third transistor and the base of the fourth transistor respectively; the emitter of the fourth transistor is electrically connected to the first end of the second voltage-stabilizing resistor; The sixth end of the target optical coupler, the collector of the third transistor, and the second end of the second stabilizing resistor are all used for grounding.

11. A method for sampling the maximum temperature of an IGBT, characterized in that: The sampling method is applied to a sampling circuit for the maximum temperature of an IGBT, wherein the sampling circuit includes at least two identical temperature sampling subcircuits, which are denoted as a first temperature sampling subcircuit and a second temperature sampling subcircuit, wherein: The first end of the first temperature sampling subcircuit is used to be electrically connected to the first end of the first temperature sampling resistor; the first end of the second temperature sampling subcircuit is used to be electrically connected to the first end of the second temperature sampling resistor; the second end of the first temperature sampling subcircuit and the second end of the second temperature sampling subcircuit are both used to be electrically connected to the data interaction end of the MCU; The sampling method includes: The sampling circuit performs preset target parameter processing on input parameters input to the sampling circuit based on the first temperature sampling subcircuit and the second temperature sampling subcircuit to obtain a target parameter processing result corresponding to the input parameter; the input parameter at least includes an input voltage; the target parameter processing includes operational amplification, voltage comparison and minimum voltage output; the target parameter processing result includes a target voltage corresponding to the minimum voltage output; The sampling circuit transmits the target parameter processing result to the MCU, so that the MCU analyzes the target parameter processing result to obtain a target temperature corresponding to the target parameter processing result, and the target temperature is a maximum value temperature corresponding to the sampling circuit.

12. The method for sampling the maximum IGBT temperature according to claim 11, characterized in that: The input parameter further includes an input current, and the target parameter processing result further includes a target current corresponding to the target voltage; and the sampling circuit further includes a voltage isolation subcircuit, wherein: The second end of the first temperature sampling subcircuit and the second end of the second temperature sampling subcircuit are both electrically connected to the input end of the voltage isolation subcircuit; the output end of the voltage isolation subcircuit is used to be electrically connected to the data interaction end of the MCU; The method further comprises: The voltage isolation subcircuit performs parameter isolation on the target parameter processing result to obtain a parameter isolation result corresponding to the target parameter processing result; the parameter isolation includes voltage regulation for the target voltage, current amplification for the target current, and signal isolation for the target signal; the target signal includes the target current and the target voltage; The voltage isolation subcircuit transmits the parameter isolation result to the MCU, so that the MCU analyzes the parameter isolation result to obtain a target temperature corresponding to the parameter isolation result.

Images