Signal sampling model, filter capacitor failure detection method and related equipment

Abstract

The present invention discloses a signal sampling model, a filter capacitor failure detection method and related equipment, including: using an analog interface to obtain an external input voltage value at the power-on time to obtain an initial voltage value Vin At time T1, the analog interface is configured as a digital push-pull output, and a high level is output to charge capacitor C. At time T2, the analog interface is configured as an analog input pin; the external input voltage signal of several cycles is continuously collected and archived through the analog interface, and the initial voltage value is calculated based on the initial voltage value. Vin and the archived external input voltage signals of several cycles to obtain the archived voltage signal value; the current capacitance value is estimated based on the archived voltage signal value to obtain the estimated capacitance value; if the deviation from the preset value of the control system is too large, it is judged that the capacitance value is reduced or failed. The adoption of the present invention is conducive to saving costs and improving the timeliness and efficiency of filter capacitor detection.

Description

Technical Field

[0001] The present invention relates to the field of motor control technology, and in particular to a signal sampling model, a failure detection method for a filter capacitor, and related equipment. Background Art

[0002] In the brushless DC motor control system, the microcontroller unit MCU is the core of the system control, responsible for the current information collection of the IPM (Intelligent Power Module), bus voltage sampling / speed command signal sampling / power device temperature information sampling, and real-time adjustment of the PWM (pulse width modulation is a control method) control signal, control of the conduction sequence of the power tube in the IPM, and realization of motor drive control. During the operation of the motor, in order to ensure the sampling quality of the motor voltage and current signals, the existing solution is to filter out the signals of the specific frequency band through the RC filter and then connect the signals to the ADC input pins in the microcontroller unit MCU to ensure that the normal signals of the specific frequency band can be sampled smoothly.

[0003] In the process of implementing the present invention, the inventors found that the existing methods have at least the following problems: During normal use of the controller, the sampled signals are generally processed by hardware RC filtering and software mean filtering. It is common for the filter capacitor to reduce its capacity or even fail due to aging, which will reduce or even fail the hardware filtering effect. If only the subsequent software filtering is relied on, the filtering effect will deteriorate, resulting in abnormal subsequent system control. Summary of the invention

[0004] The embodiments of the present invention provide a signal sampling model, a filter capacitor failure detection method and related equipment to improve the timeliness and accuracy of failure detection of a brushless DC motor filter capacitor.

[0005] In order to solve the above technical problems, an embodiment of the present application provides a signal sampling model, including: a microcontroller unit MCU, a sampling resistor Rs and an RC filter, wherein the RC filter includes a first resistor R and a capacitor C, the microcontroller unit includes an internal analog-to-digital conversion module, and the external input voltage signal flows to the ground line through the sampling resistor Rs. Above the sampling resistor Rs, the signal is also filtered through a low-pass filter composed of the first resistor R and the capacitor C, and then input into the ADC module inside the microcontroller unit MCU to realize signal acquisition.

[0006] In order to solve the above technical problems, the embodiment of the present application further provides a failure detection method of a filter capacitor, which is applied to the above signal sampling model. The failure detection method of the filter capacitor includes:

[0007] Use the analog interface to obtain the external input voltage value at the power-on time to obtain the initial voltage value Vin ;

[0008] At time T1, the analog interface is configured as a digital push-pull output and outputs a high level to charge the capacitor C. At time T2, the analog interface is configured as an analog input pin;

[0009] The external input voltage signal of several cycles is continuously collected and archived through the analog interface, and the initial voltage value is calculated based on the Vin and the archived external input voltage signals of several cycles to obtain archived voltage signal values;

[0010] estimating a current capacitance value based on the archived voltage signal value to obtain an estimated capacitance value;

[0011] If the deviation from the preset value of the control system is too large, it is judged that the capacitance value is reduced or failed.

[0012] Optionally, at time T2, the charging of the capacitor C in the RC filter is completed and the voltage reaches a maximum value.

[0013] Optionally, the capacitor C in the RC filter is discharged through the first resistor R and the sampling resistor Rs connected in series, and the voltage gradually decreases exponentially over time and is consistent with the initial Vin voltage after stabilization.

[0014] Optionally, AD sampling signal collection is synchronously started at time T2, and the discharge curve of the capacitor C is sampled at a certain period. When the voltage of the capacitor C drops to the threshold voltage Vthreshold, the current time T△ is recorded.

[0015] Optionally, if the capacitance of the capacitor decreases or fails, the time T△ is used as the current filter coefficient.

[0016] Optionally, after the step of determining that the capacitance value of the capacitor is reduced or failed if the deviation from the preset value of the control system is too large, the failure detection method of the filter capacitor further includes:

[0017] The current filter coefficient is recalculated according to the estimated capacitance value, and the current capacitance value is calculated according to the current filter coefficient to obtain a corrected capacitance value.

[0018] In order to solve the above technical problems, the embodiment of the present application further provides a failure detection device for a filter capacitor, comprising:

[0019] The first acquisition module is used to obtain the external input voltage value at the power-on time using the analog interface to obtain the initial voltage value Vin ;

[0020] The interface conversion module is used to configure the analog interface to a digital push-pull output at time T1 and output a high level to charge the capacitor C, and to configure the analog interface to an analog input pin at time T2;

[0021] The second acquisition module is used to continuously acquire a plurality of cycles of external input voltage signals through an analog interface and archive them, and according to the initial voltage value Vin and the archived external input voltage signals of several cycles to obtain archived voltage signal values;

[0022] A capacitance estimation module, used to estimate a current capacitance value based on the archived voltage signal value to obtain an estimated capacitance value;

[0023] The failure judgment module is used to judge that the capacitance value is reduced or failed if the deviation from the preset value of the control system is too large.

[0024] In order to solve the above technical problems, an embodiment of the present application also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above-mentioned filter capacitor failure detection method when executing the computer program.

[0025] In order to solve the above technical problems, an embodiment of the present application further provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the above-mentioned filter capacitor failure detection method are implemented.

[0026] The signal sampling model, filter capacitor failure detection method and related equipment provided by the embodiment of the present invention obtain the external input voltage value at the power-on time by using an analog interface to obtain the initial voltage value Vin At time T1, the analog interface is configured as a digital push-pull output, and a high level is output to charge capacitor C. At time T2, the analog interface is configured as an analog input pin; the external input voltage signal of several cycles is continuously collected and archived through the analog interface, and the initial voltage value is calculated based on the initial voltage value. Vin and the archived external input voltage signals of several cycles to obtain the archived voltage signal value; based on the archived voltage signal value, the current capacitance value is estimated to obtain the estimated capacitance value; if the deviation from the preset value of the control system is too large, it is judged that the capacitance value is reduced or failed. The embodiment does not need to add additional hardware short circuit, but realizes the capacitance detection in the RC filter through software programming. It can realize the inspection of abnormal conditions such as reduced capacitance or even failed open circuit, provide an effective judgment basis for subsequent control strategies, help save costs, and improve the timeliness and efficiency of capacitance detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0028] Figure 1 This is a schematic diagram of the conventional brushless DC motor control topology;

[0029] Figure 2 It is a simplified model schematic diagram of the analog-to-digital converter sampling voltage and current signals of the present application;

[0030] Figure 3 It is a flow chart of an embodiment of a method for detecting a failure of a filter capacitor of the present application;

[0031] Figure 4 It is a schematic diagram of the implementation process of an embodiment of the failure detection method of the filter capacitor of the present application;

[0032] Figure 5 is a structural schematic diagram of an embodiment of a filter capacitor failure detection device according to the present application;

[0033] Figure 6 It is a structural diagram of an embodiment of a computer device according to the present application. DETAILED DESCRIPTION

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of the present application; the terms used in the specification of the application herein are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "including" and "having" and any variations thereof in the specification and claims of the present application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of the present application or the above-mentioned drawings are used to distinguish different objects, not to describe a specific order.

[0035] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0036] Some of the names involved in the application examples are explained as follows:

[0037] ADC: The abbreviation of Analog-to-Digital Converter, which refers to analog / digital converter or analog-to-digital converter. It refers to a device that converts continuously changing analog signals into discrete digital signals.

[0038] RC: Also known as RC filter circuit, it is a circuit composed of resistors and capacitors, used to filter signals. Its main function is to select signals of a specific frequency, retain frequencies in a certain frequency band, and filter out frequencies outside the frequency band.

[0039] MCU: Microcontroller unit, also known as single chip microcomputer, is the core of system sampling and control

[0040] PWM: Pulse Width Modulation is a control method

[0041] IPM: In motor drive, IPM (Intelligent Power Module) is a highly integrated semiconductor device specifically used to control and drive high-power electronic devices such as AC motor drives, frequency converters, inverters, etc. The IPM module integrates multiple functional modules, including but not limited to power switches, drive circuits, protection circuits, and control circuits.

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] See also Figure 1 ,like Figure 1 As shown, Figure 1 This is a common brushless DC motor control topology in existing methods. The MCU is the core of system control, responsible for the current information collection of the IPM, bus voltage sampling / speed command signal sampling / power device temperature information sampling, and real-time adjustment of the PWM control signal to control the conduction sequence of the power tubes in the IPM to achieve motor drive control. During the operation of the motor, in order to ensure the sampling quality of the motor voltage and current signals, the existing solution filters these signals through an RC filter to remove the signals in a specific frequency band and then connects the signals to the ADC input pins in the MCU to ensure that the normal signals in the specific frequency band can be sampled smoothly.

[0044] Please continue reading Figure 2 , Figure 2It is a simplified model schematic diagram of an analog-to-digital converter sampling voltage and current signals in this embodiment, including: a microcontroller unit MCU, a sampling resistor Rs and an RC filter, wherein the RC filter includes a first resistor R and a capacitor C, and the microcontroller unit includes an internal analog-to-digital conversion module. The external input voltage signal flows to the ground line through the sampling resistor Rs, and the signal is also low-pass filtered by the first resistor R and the capacitor C above the sampling resistor Rs, and then input to the ADC module inside the microcontroller unit MCU to realize signal acquisition.

[0045] In this embodiment, there is no need to add additional hardware short circuit, but the capacitance detection in the RC filter is realized through software programming. It can realize the detection of abnormal conditions such as reduced capacitance or even failure open circuit, and provide an effective judgment basis for subsequent control strategies. It is conducive to saving costs and improving the timeliness and efficiency of capacitance detection.

[0046] See also Figure 3 , Figure 3 A method for detecting a failure of a filter capacitor provided by an embodiment of the present invention is shown. Figure 2 The signal sampling model in is explained as follows:

[0047] S201: using an analog interface to obtain an external input voltage value at the power-on time to obtain an initial voltage value Vin.

[0048] Specifically, this embodiment generates an excitation level signal for the signal sampling port when the system is powered on, and then samples the analog voltage value of the signal after the external circuit discharges for a certain period of time. Subsequently, by comparing this value with the initial value of the system when it leaves the factory, the current system hardware RC filter time is estimated, and the software matches the corresponding filter depth. Signal acquisition and software compensation are achieved by adjusting the filter depth. Signal accuracy and real-time performance are guaranteed. An effective data source is provided for the subsequent control loop, thereby ensuring efficient and stable operation of the system.

[0049] S202: At time T1, the analog interface is configured as a digital push-pull output, and outputs a high level to charge the capacitor C. At time T2, the analog interface is configured as an analog input pin.

[0050] S203: Continuously collect external input voltage signals for several cycles through the analog interface and archive them, and then calculate the initial voltage value according to the initial voltage value. V i n and the archived external input voltage signals of several cycles to obtain archived voltage signal values.

[0051] Furthermore, at time T2, the charging of the capacitor C in the RC filter is completed and the voltage reaches the maximum value.

[0052] Furthermore, the capacitor C in the RC filter is discharged through the first resistor R and the sampling resistor Rs connected in series, and the voltage gradually decreases exponentially over time and is consistent with the initial Vin voltage after stabilization.

[0053] Furthermore, AD sampling signal collection is synchronously started at time T2, and the discharge curve of the capacitor C is sampled at a certain period. When the voltage of the capacitor C drops to the threshold voltage Vthreshold, the current time T△ is recorded.

[0054] Specifically, at time T2, the charging of capacitor C in the RC filter is completed and the voltage reaches the maximum value Vmax. At this time, the pin is reconfigured as an analog pin. At this time, the capacitor C in the RC filter is discharged through the series connection of resistor R and sampling resistor Rs, and the voltage gradually decreases exponentially over time, and after stabilization, it is consistent with the initial Vin voltage. Since the pin is configured as an analog pin, the internal impedance is very high, reaching the megohm level, and the discharge of capacitor C through the IO hardware in the MCU can be ignored.

[0055] Figure 4 1 is a schematic diagram of the implementation process of an embodiment of the filter capacitor failure detection method of the present application, wherein Vthreshold is the threshold voltage, and Vmax is the maximum voltage.

[0056] In this embodiment, the threshold voltage Vthreshold is a reference voltage set by software. When the capacitor voltage drops to the reference voltage, the time length T△ to this moment is recorded.

[0057] It should be noted that in this embodiment, for the capacitor discharge curve after charging, the charging and discharging timing is not required, and the charging curve can be charged first and then detected, or discharged first and then detected. However, the overall idea of ​​detecting the charging and discharging time of the RC filter by generating an excitation signal remains unchanged. The algorithm processing after sampling the capacitor charging / discharging is not unique.

[0058] S204: estimating a current capacitance value based on the archived voltage signal value to obtain an estimated capacitance value.

[0059] S205: If the deviation from the preset value of the control system is too large, it is determined that the capacitance value of the capacitor is reduced or failed.

[0060] Furthermore, if the capacitance of the capacitor decreases or fails, the time T△ is used as the current filter coefficient.

[0061] Further, after the step of determining that the capacitance value of the capacitor is reduced or failed if the deviation from the preset value of the control system is too large, the failure detection method of the filter capacitor further includes:

[0062] The current filter coefficient is recalculated according to the estimated capacitance value, and the current capacitance value is calculated according to the current filter coefficient to obtain a corrected capacitance value.

[0063] If the difference between the T△ time and the system initialization time reaches a certain range, it is determined that the capacitance in the circuit is abnormal at this time, and the time T△ is added as a filter coefficient to the post-stage system control, and the impact caused by the reduction of the RC filter effect is compensated. It should be understood that the compensation for the impact caused by the reduction of the RC filter effect is to avoid the failure of software control due to the abnormality of the RC filter circuit.

[0064] In this embodiment, an analog interface is used to obtain the external input voltage value at the power-on time to obtain the initial voltage value. Vin At time T1, the analog interface is configured as a digital push-pull output, and a high level is output to charge capacitor C. At time T2, the analog interface is configured as an analog input pin; the external input voltage signal of several cycles is continuously collected and archived through the analog interface, and the initial voltage value is calculated based on the initial voltage value. Vin and the archived external input voltage signals of several cycles to obtain the archived voltage signal value; based on the archived voltage signal value, the current capacitance value is estimated to obtain the estimated capacitance value; if the deviation from the preset value of the control system is too large, it is judged that the capacitance value is reduced or failed. This embodiment does not require additional hardware short circuits, but implements capacitance detection in RC filters through software programming. It can realize abnormal situation inspections such as reduced capacitance or even failed open circuits, providing an effective judgment basis for subsequent control strategies. It is conducive to saving costs and improving the timeliness and efficiency of capacitance detection.

[0065] It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0066] Figure 5 The principle block diagram of the filter capacitor failure detection device corresponding to the filter capacitor failure detection method of the above embodiment is shown. Figure 5 As shown, the filter capacitor failure detection device includes a first acquisition module 31, an interface conversion module 32, a second acquisition module 33, a capacitance estimation module 34 and a failure judgment module 35. The functional modules are described in detail as follows:

[0067] The first acquisition module 31 is used to obtain the external input voltage value at the power-on time by using an analog interface to obtain the initial voltage value Vin ;

[0068] The interface conversion module 32 is used to configure the analog interface to a digital push-pull output at time T1 and output a high level to charge the capacitor C, and configure the analog interface to an analog input pin at time T2;

[0069] The second acquisition module 33 is used to continuously acquire a plurality of cycles of external input voltage signals through an analog interface and archive them, and according to the initial voltage value Vin and the archived external input voltage signals of several cycles to obtain archived voltage signal values;

[0070] A capacitance estimation module 34, configured to estimate a current capacitance value based on the archived voltage signal value to obtain an estimated capacitance value;

[0071] The failure judgment module 35 is used to judge that the capacitance value is reduced or failed if the deviation from the preset value of the control system is too large.

[0072] The specific definition of the failure detection device of the filter capacitor can be found in the definition of the failure detection method of the filter capacitor mentioned above, which will not be repeated here. Each module in the above-mentioned failure detection device of the filter capacitor can be implemented in whole or in part by software, hardware and a combination thereof. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above modules.

[0073] To solve the above technical problems, the present application also provides a computer device. Figure 6 , Figure 6 This is a basic structural block diagram of the computer device in this embodiment.

[0074] The computer device 4 includes a memory 41, a processor 42, and a network interface 43 that are interconnected through a system bus. It should be noted that the figure only shows a computer device 4 with components connected to the memory 41, the processor 42, and the network interface 43, but it should be understood that it is not required to implement all the components shown, and more or fewer components can be implemented instead. Among them, those skilled in the art can understand that the computer device here is a device that can automatically perform numerical calculations and / or information processing according to pre-set or stored instructions, and its hardware includes but is not limited to microprocessors, application specific integrated circuits (Application Specific Integrated Circuit, ASIC), programmable gate arrays (Field-Programmable Gate Array, FPGA), digital processors (Digital Signal Processor, DSP), embedded devices, etc.

[0075] The computer device may be a computing device such as a desktop computer, a notebook, a PDA, a cloud server, etc. The computer device may interact with a user through a keyboard, a mouse, a remote controller, a touch pad, or a voice control device.

[0076] The memory 41 includes at least one type of readable storage medium, and the readable storage medium includes flash memory, hard disk, multimedia card, card-type memory (for example, SD or D interface display memory, etc.), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), programmable read-only memory (PROM), magnetic memory, disk, optical disk, etc. In some embodiments, the memory 41 can be an internal storage unit of the computer device 4, such as a hard disk or memory of the computer device 4. In other embodiments, the memory 41 can also be an external storage device of the computer device 4, such as a plug-in hard disk equipped on the computer device 4, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), etc. Of course, the memory 41 can also include both the internal storage unit of the computer device 4 and its external storage device. In this embodiment, the memory 41 is usually used to store the operating system and various application software installed on the computer device 4, such as the program code of the failure detection method of the filter capacitor, etc. In addition, the memory 41 can also be used to temporarily store various types of data that have been output or are to be output.

[0077] The processor 42 may be a central processing unit (CPU), a controller, a microcontroller, a microprocessor, or other data processing chips in some embodiments. The processor 42 is generally used to control the overall operation of the computer device 4. In this embodiment, the processor 42 is used to run the program code stored in the memory 41 or process data, such as running the program code of the failure detection method of the filter capacitor.

[0078] The network interface 43 may include a wireless network interface or a wired network interface. The network interface 43 is generally used to establish a communication connection between the computer device 4 and other electronic devices.

[0079] The present application also provides another implementation, namely, providing a computer-readable storage medium, wherein the computer-readable storage medium stores an interface display program, and the interface display program can be executed by at least one processor to enable the at least one processor to perform the steps of the failure detection method of the filter capacitor as described above.

[0080] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), and includes a number of instructions for a terminal device (which can be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in each embodiment of the present application.

[0081] Obviously, the embodiments described above are only some embodiments of the present application, rather than all embodiments. The preferred embodiments of the present application are given in the accompanying drawings, but they do not limit the patent scope of the present application. The present application can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive. Although the present application is described in detail with reference to the aforementioned embodiments, for those skilled in the art, it is still possible to modify the technical solutions recorded in the aforementioned specific implementation methods, or to replace some of the technical features therein with equivalents. Any equivalent structure made using the contents of the specification and drawings of this application, directly or indirectly used in other related technical fields, is similarly within the scope of patent protection of this application.

Claims

1. A signal sampling model, characterized in that: include: A microcontroller unit MCU, a sampling resistor Rs and an RC filter, wherein the RC filter includes a first resistor R and a capacitor C, and the microcontroller unit includes an internal analog-to-digital conversion module. The external input voltage signal flows to the ground line through the sampling resistor Rs, and above the sampling resistor Rs, the signal is also filtered by a low-pass filter composed of the first resistor R and the capacitor C, and then input to the ADC module inside the microcontroller unit MCU to realize signal acquisition.

2. A method for detecting failure of a filter capacitor, characterized in that: Applied to the above signal sampling model, the failure detection method of the filter capacitor includes: Use the analog interface to obtain the external input voltage value at the power-on time to obtain the initial voltage value Vin ; At time T1, the analog interface is configured as a digital push-pull output and outputs a high level to charge the capacitor C. At time T2, the analog interface is configured as an analog input pin; The external input voltage signal of several cycles is continuously collected and archived through the analog interface, and the initial voltage value is calculated based on the V i n and the archived external input voltage signals of several cycles to obtain archived voltage signal values; estimating a current capacitance value based on the archived voltage signal value to obtain an estimated capacitance value; If the deviation from the preset value of the control system is too large, it is judged that the capacitance value is reduced or failed.

3. The failure detection method of the filter capacitor according to claim 2, characterized in that: At time T2, the charging of capacitor C in the RC filter is completed and the voltage reaches the maximum value.

4. The method for detecting failure of a filter capacitor according to claim 3, characterized in that: The capacitor C in the RC filter is discharged through the first resistor R and the sampling resistor Rs in series, and the voltage decreases exponentially over time and is consistent with the initial Vin voltage after stabilization.

5. The failure detection method of the filter capacitor according to claim 3, characterized in that: At time T2, AD sampling signal acquisition is synchronously started, and the discharge curve of capacitor C is sampled at a certain period. When the voltage of capacitor C drops to the threshold voltage Vthreshold, the current time T△ is recorded.

6. The failure detection method of the filter capacitor according to claim 5, characterized in that: If the capacitance value of the capacitor decreases or fails, the time T△ is used as the current filter coefficient.

7. The method for detecting failure of a filter capacitor according to claim 6, characterized in that: After the step of determining that the capacitance value of the capacitor is reduced or failed if the deviation from the preset value of the control system is too large, the failure detection method of the filter capacitor further includes: The current filter coefficient is recalculated according to the estimated capacitance value, and the current capacitance value is calculated according to the current filter coefficient to obtain a corrected capacitance value.

8. A filter capacitor failure detection device, characterized in that: include: The first acquisition module is used to obtain the external input voltage value at the power-on time using the analog interface to obtain the initial voltage value Vin ; The interface conversion module is used to configure the analog interface to a digital push-pull output at time T1 and output a high level to charge the capacitor C, and to configure the analog interface to an analog input pin at time T2; The second acquisition module is used to continuously acquire a plurality of cycles of external input voltage signals through an analog interface and archive them, and according to the initial voltage value Vin and the archived external input voltage signals of several cycles to obtain archived voltage signal values; A capacitance estimation module, used to estimate a current capacitance value based on the archived voltage signal value to obtain an estimated capacitance value; The failure judgment module is used to judge that the capacitance value is reduced or failed if the deviation from the preset value of the control system is too large.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the failure detection method for the filter capacitor according to any one of claims 2 to 7 is implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the failure detection method for a filter capacitor as claimed in any one of claims 2 to 7 is implemented.

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