A functional safety control device and method for power electronic system

Abstract

The present invention discloses a functional safety control device and method for a power electronic system. The device includes a power electronic switch tube, a power electronic switch tube drive circuit, and is characterized in that it also includes an overload control module, a host computer and a main control circuit, wherein the overload control module is respectively connected to the power electronic switch tube, the power electronic switch tube drive circuit, the host computer and the main control circuit, and the overload control module determines the safe current or safe power based on the control command from the host computer and the collected temperature data of the power electronic switch tube, so as to adjust the main control circuit to generate a corresponding pulse width modulation wave to drive the power electronic switch tube. The present invention can calculate the optimal safe current or safe power in real time, thereby ensuring that the temperature of the power electronic equipment does not exceed the safe range when the power electronic equipment is overloaded.

Description

Technical Field

[0001] The present invention relates to the field of power electronics technology, and more specifically, to a power electronics system functional safety control device and method. Background Art

[0002] The rated current or power of existing power electronic systems such as motor drives, power supplies, rectifiers, and inverters are the current or power corresponding to the power electronic system when the power electronic devices (switches) can operate below the temperature limit for a long time. However, in actual use, due to differences in ambient temperature, equipment start-stop frequency, and full-load operating time, the rated operating current and power of power electronic equipment will have a large margin. These margins cause the rated current or power of the switch tube of electrical and electronic equipment to be too large, and also cause the size and weight of the power electronic equipment to be too large, resulting in a lot of unnecessary expenses and costs for the overall product.

[0003] At present, there is no device or equipment that can accurately control the overload operation of power electronic equipment. When designing power electronic equipment, overly conservative power electronic switch tube selection and control schemes are often adopted. For example, according to the rated current or power of the load and with a certain margin, when the temperature of the power electronic switch tube is too high, the device is shut down to cool down. Therefore, the existing scheme adds a lot of extra expenses and costs to the final product and affects the product performance. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a functional safety control device and method for a power electronic system, which can maximize the overload performance of the system while ensuring that the temperature of the power electronic switch tube is not greater than the maximum operating temperature.

[0005] According to a first aspect of the present invention, a functional safety control device for a power electronic system is provided. The device comprises a power electronic switch tube, a power electronic switch tube drive circuit, an overload control module, a host computer and a main control circuit, wherein the overload control module is respectively connected to the power electronic switch tube, the power electronic switch tube drive circuit, the host computer and the main control circuit, and the overload control module determines the safety current I based on the control command from the host computer and the collected temperature data of the power electronic switch tube. max Or safety power P e_max , so as to adjust the main control circuit to generate a corresponding pulse width modulation wave to drive the power electronic switch tube via the power electronic switch tube driving circuit.

[0006] In one embodiment, the control command sent by the host computer indicates that the current is less than I max Or the power is less than P e_maxIn this case, the overload control module directly transmits the control command of the host computer to the main control circuit, and the main control circuit generates a pulse width modulation wave of corresponding frequency and duty cycle to drive the power electronic switch tube.

[0007] In one embodiment, when the control command sent by the host computer indicates that the current is greater than I max Or the power is greater than P e_max In this case, the overload control module sends the received control command of the host computer to the main control circuit and instructs the host computer to reduce power or current.

[0008] In one embodiment, the overload control module is configured to determine the safety current I according to the following method: max :

[0009] Set the prediction time range and prediction time step, and obtain the total heat dissipation of the power electronic switch tube within the prediction time range based on the heat dissipated by the power electronic switch tube within different prediction time steps.

[0010] Based on total heat dissipation Determine the maximum energy absorbed by the power electronic switch within the predicted time range

[0011] According to the obtained and the temperature variation information of the power electronic switch tube, determine Corresponding safety current I max .

[0012] In one embodiment, the overload control module is configured to determine the output current or power based on a limit PI controller, including:

[0013] The temperature limit T of the power electronic switch tube lim With the temperature measurement value T S The difference input limit PI controller;

[0014] In T lim Greater than or equal to T S In the case of a load condition, the output of the PI controller is limited to 0, the output of the PI controller plus the current or power indicated by the host computer is used as the output of the overload control module, and is output to the main control circuit for generating a corresponding pulse width modulation wave;

[0015] In T lim Less than T S In the case where the output of the limiting PI controller is a negative value, limiting the output of the PI controller will reduce the current or power indicated by the host computer and reduce the output of the overload control module until T limGreater than or equal to T S until.

[0016] In one embodiment, the overload control module is configured as an independent module, or is integrated into the host computer or the main control circuit in the form of a submodule.

[0017] According to a second aspect of the present invention, a method for functional safety control of a power electronic system is provided, the method comprising: collecting temperature data of a power electronic switch tube in real time; determining a safe current or a safe power based on the collected temperature data of the power electronic switch tube, so as to adjust a main control circuit to generate a corresponding pulse width modulation wave to drive the power electronic switch tube.

[0018] Compared with the prior art, the advantage of the present invention is that by monitoring the temperature and current of the power electronic switch tube and controlling the overload of the power electronic device, the current or power of the power electronic system can be regulated, and the overload performance of the system can be maximized while ensuring that the temperature of the power electronic switch tube is not higher than the maximum operating temperature.

[0019] Further features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0021] Figure 1 is a schematic diagram of a functional safety control device for a power electronic system according to an embodiment of the present invention;

[0022] Figure 2 is a flowchart of the processing of the current or power command transmitted by the host computer by the overload control module according to one embodiment of the present invention;

[0023] Figure 3 is a schematic diagram of calculating a safe current or safe power based on model predictive control according to an embodiment of the present invention;

[0024] Figure 4 is a schematic diagram of solving a safety current or safety power based on a PI controller according to an embodiment of the present invention;

[0025] Figure 5 is a schematic diagram of an overload control module according to an embodiment of the present invention. DETAILED DESCRIPTION

[0026] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless otherwise specifically stated.

[0027] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0028] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0029] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0030] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0031] The present invention provides a functional safety control device for a power electronic system, see Figure 1 As shown, the device includes a power electronic switch tube 120 (or simply a switch tube), a power electronic switch tube drive circuit 140, a host computer 130 and an overload control module 110 (or a power electronic system overload operation control device). The host computer 130 is used to control the power electronic system. For example, the host computer 130 is a computer that directly sends control commands, and a variety of signal changes can be displayed on the screen. The overload control module 110 can exist in various forms, such as being set as an independent module, or integrated in the main control circuit or integrated in the host computer in the form of a submodule. For example, the overload control module 110 can be connected in series between the power electronic drive circuit and the controller of the main control circuit, or integrated in the controller. The overload control module 110 monitors the temperature and current of the power electronic switch tube 120, and realizes the regulation of the current or power of the power electronic system through the overload control algorithm, while ensuring that the temperature of the switch tube is not greater than the maximum operating temperature, to maximize the overload performance of the power electronic system.

[0032] Specifically, combined Figure 1 and Figure 2 As shown in FIG. 1 , the host computer first sends the current or power command to the overload control module of the present invention, and the overload control module also collects the current, temperature and other data of the controlled power electronic switch tube in real time. Based on the collected current, temperature and other information of the power electronic switch tube, the overload control module can calculate the optimal safety current (I max ) or safety power (Pe_max ), the optimal safe current or safe power mentioned in the present invention refers to the maximum current or maximum power that the power electronic system can carry while ensuring that the temperature of the switch tube is not greater than the maximum operating temperature.

[0033] In one case, when the current or power command from the host computer is less than I max or P e_max When the overload control module transmits the current, power and other commands of the host computer directly to the main control circuit of the power electronic equipment, the main control circuit will generate a PWM wave (pulse width modulation wave) with a certain frequency and a certain duty cycle (or modulation ratio) according to the current or power command. The generated PWM wave will be sent to the power electronic switch tube drive circuit, thereby driving the power electronic switch to turn on or off, realizing the regulation of electric energy.

[0034] In another case, when the current command sent by the host computer is greater than I max Or the power command is greater than P e_max When the overload control module will I max or P e_max It is sent to the main control circuit and notified to the host computer, which makes the host computer reduce the power, current command and action frequency according to the actual situation to cool the system.

[0035] It should be noted that, since the rated power and current of the power electronic system are the maximum current or power at which the temperature of the power electronic switch tube does not exceed the safety value when the system works for a long time, the I max or P e_max It will always be greater than or equal to the rated current and power of the system. Therefore, the present invention can ensure that the power electronic system can fully utilize the extra power provided by the overload operation of the power electronic system under safe conditions (temperature does not exceed the maximum temperature), thereby improving the power density of the system.

[0036] The overload control module provided by the present invention can calculate I in a variety of ways. max and P e_max , for example including but not limited to model-based predictive control or PI controller regulation.

[0037] 1) About model-based predictive control

[0038] Considering the power electronic switch tube as a lumped parameter node, according to the definition of specific heat capacity, the temperature rise of the power electronic switch tube can be expressed as:

[0039]

[0040] Among them, Q inW is the heat generated by the power electronic switch tube, that is, the heat generated by turn-on loss, turn-off loss, conduction loss, etc. in The power of heat generated by the switch tube in each time step Δt; Q out is the amount of heat transferred from the switch tube to the radiator or the environment through conduction, radiation and convection; C is the equivalent specific heat capacity, m is the equivalent mass of the switch tube, and the heat dissipation power W out It can be approximately expressed as:

[0041]

[0042] Among them, T S is the temperature of the switch tube, T amb is the ambient temperature, R T is the equivalent thermal resistance, which can be obtained through steady-state experiments based on formulas (1) and (2) and stored in a data table whose input is the switching frequency and current amplitude of the switch tube and whose output is the equivalent thermal resistance. T It can be expressed as W out The nonlinear relationship between the switching tube temperature.

[0043] Assume that the number of time steps in the prediction range of the model predictive control is N, and the temperature rise of the switch tube in each prediction time step is the same. According to formula (2), the heat dissipated in different time steps can be predicted as:

[0044]

[0045]

[0046]

[0047] …

[0048]

[0049] The superscripts in equations (3) to (6) above represent the sequence number of the time step, ΔT S is the temperature rise of the switch tube in each prediction step, and the total heat dissipation within the prediction range can be expressed as:

[0050]

[0051]

[0052] The control goal of the model predictive control is to adaptively limit the temperature of the switch tube to a preset temperature value T when the power electronic system is overloaded. lim Below. Under extreme conditions, the switch tube temperature should be equal to T in steady state. limTherefore, the maximum energy absorbed by the switch within the predicted time range is It can be expressed as:

[0053]

[0054] Among them, T S is the temperature of the switch tube, and the equivalent heat m of the switch tube can be obtained through experiments or calculated according to the package size of the switch tube. Therefore, the maximum temperature rise of the corresponding switch tube in each prediction step is:

[0055]

[0056] By measuring T S , we can substitute formula (8) and formula (10) into formula (9) to obtain

[0057] According to the maximum energy absorbed by the switch tube within the predicted time range Based on the relationship between the switch loss and the switching frequency, current and other factors, we can infer The corresponding maximum current value and the corresponding switching frequency. It is related to both the switching frequency and the current value, and the switching frequency is determined by the load characteristics. Therefore, the minimum switching frequency that meets the working performance should be determined first according to the load characteristics, and then the maximum current amplitude should be determined on this basis.

[0058] Figure 3 It is based on model predictive control calculation I max or P e_max Principle block diagram. Figure 3 T lim and N are the temperature limit of the switch tube and the number of time steps in the prediction range, respectively. S and T amb They are the measured value of the switch tube temperature and the ambient temperature value respectively. max It is to ensure that the temperature of the switch tube does not exceed T in steady state. lim Since the minimum PWM switching frequency of the switch tube is determined by the load characteristics, after determining the minimum switching frequency, it can be based on Get I max . Assume that in each prediction step, the current increases with the same amplitude ΔI a Increase or decrease based on The maximum current amplitude change within a time step can be calculated Right now Figure 3 In All prediction steps The current measured with the current I a Add them together to get Imax It should be understood that in obtaining I max After that, P can be further calculated based on the relationship between current and power. e_max .

[0059] 2) About the adjustment method using PI controller

[0060] Figure 4 It is based on the PI controller to solve I max or P e_max The PI controller is used to form a control deviation based on the given value and the actual output value, and the proportion and integral of the deviation are linearly combined to form the control quantity to control the controlled object. Specifically, T lim and the switch tube temperature T S The difference is input into the limit PI controller. If T lim Greater than or equal to T S , the output of the PI controller is limited to 0, otherwise it is a negative value. Add the output of the PI controller to the current command I of the host computer. a_ref , which is the output of the invented overload control module, and is output to the main control circuit of the power electronic equipment for generating the corresponding PWM. Figure 5 It can be seen that when T lim Less than T S When the actual temperature of the switch tube is greater than the maximum temperature limit allowed, limiting the output of the PI controller will reduce the current command I a_ref and the output of the proposed overload control module until T lim Greater than or equal to T S If T lim Greater than or equal to T S , then the output of the PI controller is limited to 0, and the output of the overload control is equal to the command I of the host computer a_ref It should be understood that Figure 4 I a_ref and I max It can also be the power command P of the host computer. e_ref and P e_max .

[0061] To further understand the present invention, Figure 5 The hardware structure block diagram of the overload control module is shown, including an analog-to-digital signal converter (AD), a microcontroller unit (MCU), a communication interface for communicating with a host computer, and a communication interface for communicating with a power electronic switch tube drive circuit, wherein the temperature and current information of the power electronic switch tube can also be directly sent by the microcontroller unit to the overload control module of the present invention through the communication interface. The microcontroller unit is mainly used to implement the overload control algorithm of the present invention.

[0062] It should be noted that the parameter units in the formulas involved in the present invention are commonly used standard units, such as the power unit is watt (W), the current unit is ampere (A), etc., which will not be repeated here. In addition, the electronic circuit components involved, such as PI controllers, switch tubes, power electronic switch tube drive circuits, etc., can be general components or special components, and the present invention does not limit this.

[0063] The simulation results show that the overload control module provided by the present invention can calculate the optimal safety current (I max ), safety power (P e_max ) and the corresponding power electronic switch tube safety PWM switching frequency, etc., and use them to limit the current, power command or other load-related commands output by the host computer, and to assist the host computer in planning the operation status of the power electronic system, so as to ensure that the temperature of the power electronic equipment does not exceed the safety range when the overload operation is in progress. The switch tube safety current (I max ), safety power (P e_max ) and the corresponding PWM switching frequency information can be sent to the host computer in real time to assist the host computer in planning the operation status of the power electronic system, and pass the PWM command after the host computer limit to the power electronic switch tube drive circuit to drive the switch tube to turn on or off, so that the temperature of the switch tube does not exceed the maximum temperature.

[0064] The present invention may be a system, a method and / or a computer program product. The computer program product may include a computer-readable storage medium carrying computer-readable program instructions for causing a processor to implement various aspects of the present invention.

[0065] A computer-readable storage medium may be a tangible device that can hold and store instructions used by an instruction execution device. A computer-readable storage medium may be, for example, but not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. More specific examples of computer-readable storage media (a non-exhaustive list) include: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a static random access memory (SRAM), a portable compact disk read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanical encoding device, such as a punch card or a raised structure in a groove on which instructions are stored, and any suitable combination of the foregoing. As used herein, a computer-readable storage medium is not to be interpreted as a transient signal per se, such as a radio wave or other freely propagating electromagnetic wave, an electromagnetic wave propagating through a waveguide or other transmission medium (e.g., a light pulse through a fiber optic cable), or an electrical signal transmitted through a wire.

[0066] The computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to each computing / processing device, or downloaded to an external computer or external storage device via a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. The network can include copper transmission cables, optical fiber transmissions, wireless transmissions, routers, firewalls, switches, gateway computers, and / or edge servers. The network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions for storage in the computer-readable storage medium in each computing / processing device.

[0067] The computer program instructions for performing the operation of the present invention may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-related instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages, such as Smalltalk, C++, etc., and conventional procedural programming languages, such as "C" language or similar programming languages. Computer-readable program instructions may be executed entirely on a user's computer, partially on a user's computer, as an independent software package, partially on a user's computer, partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., using an Internet service provider to connect via the Internet). In some embodiments, an electronic circuit, such as a programmable logic circuit, a field programmable gate array (FPGA), or a programmable logic array (PLA), may be personalized by utilizing the state information of the computer-readable program instructions, and the electronic circuit may execute the computer-readable program instructions, thereby realizing various aspects of the present invention.

[0068] Various aspects of the present invention are described herein with reference to the flow charts and / or block diagrams of the methods, devices (systems) and computer program products according to embodiments of the present invention. It should be understood that each box of the flow chart and / or block diagram and the combination of each box in the flow chart and / or block diagram can be implemented by computer-readable program instructions.

[0069] These computer-readable program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, thereby producing a machine, so that when these instructions are executed by the processor of the computer or other programmable data processing device, a device that implements the functions / actions specified in one or more boxes in the flowchart and / or block diagram is generated. These computer-readable program instructions can also be stored in a computer-readable storage medium, and these instructions cause the computer, programmable data processing device, and / or other equipment to work in a specific manner, so that the computer-readable medium storing the instructions includes a manufactured product, which includes instructions for implementing various aspects of the functions / actions specified in one or more boxes in the flowchart and / or block diagram.

[0070] Computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device so that a series of operating steps are performed on the computer, other programmable data processing apparatus, or other device to produce a computer-implemented process, thereby causing the instructions executed on the computer, other programmable data processing apparatus, or other device to implement the functions / actions specified in one or more boxes in the flowchart and / or block diagram.

[0071] The flow charts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the systems, methods and computer program products according to multiple embodiments of the present invention. In this regard, each box in the flow chart or block diagram can represent a part of a module, a program segment or an instruction, and a part of the module, a program segment or an instruction contains one or more executable instructions for realizing the specified logical function. In some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flow chart, and the combination of the boxes in the block diagram and / or flow chart can be implemented by a dedicated hardware-based system that performs the specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions. It is well known to those skilled in the art that it is equivalent to implement it by hardware, implement it by software, and implement it by combining software and hardware.

[0072] Embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements in the marketplace, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein. The scope of the present invention is defined by the appended claims.

Claims

1. A functional safety control method for a power electronic system, comprising: Real-time collection of temperature data of power electronic switch tubes; Determine the safe current I based on the collected temperature data of the power electronic switch tube max Or safety power P e_max , so as to adjust the main control circuit to generate a corresponding pulse width modulation wave to drive the power electronic switch tube; The safety current I is determined according to the following method: max : Set the prediction time range and prediction time step, and obtain the total heat dissipation of the power electronic switch tube within the prediction time range based on the heat dissipated by the power electronic switch tube within different prediction time steps. Based on total heat dissipation Determine the maximum energy absorbed by the power electronic switch within the predicted time range According to the obtained and the temperature variation information of the power electronic switch tube, determine Corresponding safety current I max ; Among them, the total heat dissipation of the power electronic switch tube is It is expressed as: The maximum energy absorbed by the power electronic switch tube within the predicted time range It is expressed as: Combined with the total heat dissipation of the power electronic switch tube The maximum temperature rise of the power electronic switch tube and the maximum energy absorbed by the power electronic switch tube within the predicted time range Determine the corresponding safe current I max ; Among them, the maximum temperature rise of the power electronic switch tube is expressed as T S is the measured temperature of the power electronic switch tube, m is the equivalent mass of the power electronic switch tube, T amb is the ambient temperature, R T is the equivalent thermal resistance, N is the number of time steps in the prediction time horizon, ΔT S is the temperature rise of the power electronic switch tube in each prediction time step, and C is the equivalent specific heat capacity.

2. A power electronic system functional safety control device, used to implement the method according to claim 1, the device comprises a power electronic switch tube, a power electronic switch tube drive circuit, an overload control module, a host computer and a main control circuit, wherein: The overload control module is respectively connected to the power electronic switch tube, the power electronic switch tube drive circuit, the host computer and the main control circuit. The overload control module determines the safety current I based on the control command from the host computer and the collected temperature data of the power electronic switch tube. max Or safety power P e_max , so as to adjust the main control circuit to generate a corresponding pulse width modulation wave to drive the power electronic switch tube via the power electronic switch tube driving circuit; The overload control module determines the safety current I according to the following method: max : Set the prediction time range and prediction time step, and obtain the total heat dissipation of the power electronic switch tube within the prediction time range based on the heat dissipated by the power electronic switch tube within different prediction time steps. Based on total heat dissipation Determine the maximum energy absorbed by the power electronic switch within the predicted time range According to the obtained and the temperature variation information of the power electronic switch tube, determine Corresponding safety current I max ; Among them, the total heat dissipation of the power electronic switch tube is It is expressed as: The maximum energy absorbed by the power electronic switch tube within the predicted time range It is expressed as: Combined with the total heat dissipation of the power electronic switch tube The maximum temperature rise of the power electronic switch tube and the maximum energy absorbed by the power electronic switch tube within the predicted time range Determine the corresponding safe current I max ; Among them, the maximum temperature rise of the power electronic switch tube is expressed as T S is the measured temperature of the power electronic switch tube, m is the equivalent mass of the power electronic switch tube, T amb is the ambient temperature, R T is the equivalent thermal resistance, N is the number of time steps in the prediction time horizon, ΔT S is the temperature rise of the power electronic switch tube in each prediction time step, and C is the equivalent specific heat capacity.

3. The power electronic system functional safety control device according to claim 2, characterized in that: When the control command sent by the host computer indicates that the current is less than I max Or the power is less than P e_max In this case, the overload control module directly transmits the control command of the host computer to the main control circuit, and the main control circuit generates a pulse width modulation wave of corresponding frequency and duty cycle to drive the power electronic switch tube.

4. The power electronic system functional safety control device according to claim 2, characterized in that: When the control command sent by the host computer indicates that the current is greater than I max Or the power is greater than P e_max In this case, the overload control module sends the received control command of the host computer to the main control circuit and instructs the host computer to reduce power or current.

5. The power electronic system functional safety control device according to claim 2, characterized in that: The overload control module is configured to determine the output current or power based on a limit PI controller, including: The temperature limit T of the power electronic switch tube lim With the temperature measurement value T S The difference input limit PI controller; In T lim Greater than or equal to T S In the case of a load condition, the output of the PI controller is limited to 0, the output of the PI controller plus the current or power indicated by the host computer is used as the output of the overload control module, and is output to the main control circuit for generating a corresponding pulse width modulation wave; In T lim Less than T S In the case where the output of the limiting PI controller is a negative value, limiting the output of the PI controller will reduce the current or power indicated by the host computer and reduce the output of the overload control module until T lim Greater than or equal to T S until.

6. The power electronic system functional safety control device according to claim 2, characterized in that: The overload control module includes an analog-to-digital signal converter and a microcontroller unit. The analog-to-digital signal converter is used to convert the received temperature information or current information of the power electronic switch tube into a digital signal. The microcontroller unit is configured to determine the safety current I according to the output of the analog-to-digital signal converter. max Or safety power P e_max , and the micro control unit is provided with a communication interface for communicating with the host computer, and a communication interface for communicating with the power electronic switch tube drive circuit.

7. The power electronic system functional safety control device according to claim 2, characterized in that: The overload control module is configured as an independent module, or integrated into the host computer or the main control circuit in the form of a submodule.

8. A computer-readable storage medium having a computer program stored thereon, wherein: When the program is executed by a processor, the steps of the power electronic system functional safety control method described in claim 1 are implemented.

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