Circuit fault detection method and system, equipment, medium and product

Abstract

The invention relates to a circuit fault detection method and system, equipment, a medium and a product. The circuit fault detection method comprises the steps of obtaining an inductance value of a preset inductor, and determining a capacitance value of a to-be-detected capacitor in a to-be-detected circuit; the preset inductor is connected with the circuit to be tested; based on the capacitance value and the inductance value, determining the resonant frequency in the to-be-tested circuit; when the resonant frequency is greater than a preset first threshold value, sending out an early warning signal; the early warning signal indicates the fault of the circuit to be detected. By adopting the method, the resonant frequency in the to-be-detected circuit after the to-be-detected capacitor is attenuated can be determined through the inductance value of the preset inductor and the capacitance value of the to-be-detected capacitor, and when the resonant frequency is too large, the early warning signal is sent out, so that circuit resonance caused after the capacitor is attenuated is effectively early warned and avoided, and the reliability of the circuit is improved. And circuit performance reduction or circuit life shortening and the like are avoided.

Description

Technical Field

[0001] The present application relates to the technical field of circuit detection, and in particular, to a circuit fault detection method, system, device, medium, and product. Background Art

[0002] With the iterative upgrade of technology, new energy vehicles not only have significantly improved performance, but their quality and safety attributes have also been increasingly emphasized. As a key component of new energy vehicles, the capacitors inside the high-voltage system play a crucial role. Capacitors can quickly store and release electrical energy to provide necessary energy support for the vehicle, and can also filter out high-frequency clutter in the circuit to ensure the purity of circuit transmission, etc. In related technologies, a capacity attenuation coefficient model of a capacitor under different ambient temperatures and different operating voltages is established, and by obtaining the average operating voltage of the capacitor and the capacity attenuation coefficient corresponding to the ambient temperature, the remaining life after the capacitor attenuation is calculated and an alarm is issued. The related technologies only calculate the remaining life of the capacitor, but do not effectively warn and avoid circuit problems caused by capacitor attenuation, which easily leads to a decline in circuit performance or a shortening of circuit life, etc. Summary of the Invention

[0003] Based on this, a circuit fault detection method, system, device, medium, and product are provided to solve the problem that in the prior art, circuit problems caused by capacitor attenuation are not detected and warned.

[0004] In a first aspect, a circuit fault detection method is provided, and the detection method includes:

[0005] Obtain the inductance value of a preset inductor and determine the capacitance value of a capacitor to be measured in a circuit to be measured; the preset inductor is connected to the circuit to be measured;

[0006] Based on the capacitance value and the inductance value, determine the resonance frequency in the circuit to be measured;

[0007] In response to the resonance frequency being greater than a preset first threshold, issue a warning signal; the warning signal indicates a fault in the circuit to be measured.

[0008] Optionally, the circuit to be measured further includes a pulse signal generator, a buffer amplifier, a current-limiting resistor, and an equivalent circuit resistor; wherein,

[0009] The non-inverting input terminal of the buffer amplifier is connected to the output terminal of the pulse signal generator,

[0010] The output terminal of the buffer amplifier is connected to the inverting input terminal of the buffer amplifier and is also connected to the first end of the current-limiting resistor;

[0011] The second end of the current-limiting resistor is connected to the first end of the equivalent circuit resistor;

[0012] The second end of the equivalent circuit resistance is connected to the first end of the capacitor under test.

[0013] Optionally, the first end of the current detecting resistor is connected to the second end of the capacitor under test, the non-inverting input terminal of the second differential amplifier is connected to the first end of the current detecting resistor, the inverting input terminal of the second differential amplifier is connected to the second end of the current detecting resistor, the non-inverting input terminal of the third differential amplifier is connected to the first end of the capacitor under test, and the inverting input terminal of the third differential amplifier is connected to the second end of the capacitor under test;

[0014] Then determining the capacitance value of the capacitor under test in the circuit under test includes:

[0015] Measuring the reference signal output by the pulse signal generator and determining the frequency of the reference signal;

[0016] Determining the first voltage value output by the first differential amplifier and determining the second voltage value output by the second differential amplifier;

[0017] Based on the first voltage value and the second voltage value, respectively determining the circuit parameters of the capacitor under test and the phase difference between the circuit parameters and the reference signal; the circuit parameters include at least one of current amplitude, voltage amplitude, voltage and current, and the phase difference includes current phase difference and / or voltage phase difference;

[0018] Based on the circuit parameters and the phase difference, determining the impedance of the capacitor under test;

[0019] Based on the product of the impedance and the frequency of the reference signal, determining the capacitance value of the capacitor under test.

[0020] Optionally, the issuing of the warning signal in response to the resonance frequency being greater than a preset first threshold includes:

[0021] When the capacitor under test is a preset capacitance value, determining the first resonance frequency of the circuit under test and the first threshold corresponding to the first resonance frequency;

[0022] When the capacitor under test is a rated capacitance value, determining the second resonance frequency of the circuit under test and the second threshold corresponding to the second resonance frequency;

[0023] When the resonance frequency is between the first threshold and the second threshold, issuing a first warning signal;

[0024] When the resonance frequency is greater than or equal to the first threshold, or the resonance frequency is less than or equal to the second threshold, issuing a second warning signal.

[0025] Optionally, the step of sending a warning signal in response to the resonance frequency being greater than a preset first threshold value includes:

[0026] acquiring a current signal of the capacitor under test in response to the resonance frequency being greater than a preset first threshold value;

[0027] determining the ripple current of the circuit under test based on the peak-to-peak value or the effective value of the current signal;

[0028] sending a third warning signal in response to the ripple current being greater than a preset third threshold value.

[0029] Optionally, when the detection method is applied to a vehicle, after sending the third warning signal in response to the ripple current being greater than a preset third threshold value, the method further includes:

[0030] reducing the acceleration of the vehicle to a preset acceleration.

[0031] In a second aspect, a circuit fault detection system is provided. The detection system includes:

[0032] a first determination module, configured to acquire an inductance value of a preset inductor and determine a capacitance value of a capacitor under test in the circuit under test; the preset inductor is connected to the circuit under test;

[0033] a second determination module, configured to determine a resonance frequency in the circuit under test based on the capacitance value and the inductance value;

[0034] a warning module, configured to send a warning signal in response to the resonance frequency being greater than a preset first threshold value; the warning signal indicates a fault in the circuit under test.

[0035] In a third aspect, an electronic device is provided, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the detection method described in the first aspect is implemented.

[0036] In a fourth aspect, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the detection method described in the first aspect is implemented.

[0037] In a fifth aspect, a computer program product is provided, including a computer program. When the computer program is executed by a processor, the detection method described in the first aspect is implemented.

[0038] Based on common general knowledge in the art, the above preferred conditions can be combined arbitrarily to obtain various preferred examples of the present application.

[0039] The above-mentioned circuit fault detection method, system, equipment, medium, and product determine the resonant frequency in the circuit to be tested after the capacitor to be tested attenuates by presetting the inductance value of the inductor and the capacitance value of the capacitor to be tested. When the resonant frequency is too large, a warning signal is issued, thereby effectively warning and avoiding the circuit resonance caused by the capacitor attenuation, thereby avoiding circuit performance degradation or shortening of circuit life. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A schematic flow chart of a circuit fault detection method according to an embodiment;

[0041] Figure 2 A schematic diagram of the structure of a circuit to be tested in a circuit fault detection method according to an embodiment;

[0042] Figure 3 A schematic diagram of the structure of some components of a main circuit of a circuit fault detection method in one embodiment;

[0043] Figure 4 Schematic diagram of the structure of a circuit fault detection system in one embodiment;

[0044] Figure 5 FIG. 1 is a schematic structural diagram of an electronic device in an embodiment. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0046] It should be noted that the diagrams provided in the present embodiment are only schematic illustrations of the basic concept of the present application. The diagrams only show the components related to the present application rather than the number, shape and size of the components when actually implemented. The type, quantity and ratio of each component can be changed at will during actual implementation, and the component layout pattern may also be more complicated. The structures, ratios, sizes, etc. illustrated in the drawings of this specification are only used to match the content disclosed in the specification for people familiar with this technology to understand and read. They are not used to limit the restrictive conditions that can be implemented in this application. Therefore, they have no technical significance. Any modification of the structure, change of the proportional relationship or adjustment of the size should still fall within the scope of the technical content disclosed in this application without affecting the effect and purpose that can be achieved by this application. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description and are not used to limit the scope of the implementation of this application. The change or adjustment of their relative relationship should also be considered as the scope of the implementation of this application without substantial change in the technical content.

[0047] As used herein, the term "embodiment" means that the specific features, structures, or characteristics described in connection with an embodiment may be included in at least one embodiment of the present application. The phrase appears at various places in the text and 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 will explicitly and implicitly understand that the embodiments described herein may be combined with other embodiments.

[0048] As shown herein, unless the context clearly indicates otherwise, words such as "a", "an", "one", and / or "the" are not specifically singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of the steps and elements that have been explicitly identified, and these steps and elements do not constitute an exclusive list. A method or device may also include other steps or elements.

[0049] The definitions included herein, such as the terms "have", "may have", "include", or "may include" as used herein, indicate the existence of the corresponding functions, operations, elements, etc. in this article, and do not limit the existence of one or more other functions, operations, elements, etc. In addition, it should be understood that the terms "include" or "have" as used herein indicate the existence of the features, numbers, steps, operations, elements, components, or combinations thereof described in the specification, and do not exclude the existence or addition of one or more other features, numbers, steps, operations, elements, components, or combinations thereof.

[0050] In the embodiments of the present application, prefix words such as "first" and "second" are only used to distinguish different described objects, and have no restrictive effect on the position, order, priority, quantity, or content of the described objects. The use of ordinal words and other prefix words for distinguishing described objects in the embodiments of the present application does not constitute a limitation on the described objects. The statements of the described objects refer to the description in the context of the claims or embodiments, and should not be construed as redundant limitations due to the use of such prefix words. In addition, in the description of this embodiment, unless otherwise specified, the meaning of "a plurality" is two or more.

[0051] In a circuit, inductors and capacitors are two main energy storage components. Among them, inductors store magnetic field energy, while capacitors store electric field energy. In a circuit containing capacitors and inductors, when the sine frequency of the external input voltage reaches a certain specific frequency, the energy exchange between the capacitor and the inductor reaches a specific balance point. At this time, the inductive reactance and capacitive reactance of the circuit are equal, and the circuit exhibits pure resistive characteristics. This specific frequency is the resonance frequency, and this phenomenon is called the resonance phenomenon, or the resonance phenomenon.

[0052] At the resonant frequency, the circuit can effectively amplify the input signal, such as amplifying the input current and voltage. This is because when the circuit is in resonance, energy is efficiently converted between the inductor and the capacitor without loss due to the presence of inductive reactance or capacitive reactance.

[0053] The inductor and the capacitor together determine the resonant frequency of the circuit. When the capacitance value remains unchanged, if the inductance value decreases, the resonant frequency will increase because the decrease in the inductance value will lead to a decrease in inductive reactance, thereby increasing the resonant frequency; when the inductance value remains unchanged, if the capacitance value decreases, the resonant frequency will also increase because the decrease in capacitance will lead to an increase in capacitive reactance, thereby increasing the resonant frequency; if the inductor and the capacitor increase or decrease simultaneously, the change in the resonant frequency depends on the relative ratio of their changes.

[0054] During the operation of the circuit, as the capacitor decays, the capacitance value decreases, and the resonant frequency will also increase accordingly. If the actual resonant frequency is too high, it may have an adverse effect on the circuit. For example, if the resonant frequency is too high, the current in the circuit may increase sharply. If it exceeds the rated current of the components in the circuit, it may cause the components to overheat and even burn out, or if the resonant frequency is too high, the resonance phenomenon may cause the voltage in the circuit to exceed the normal operating voltage, thereby damaging the insulating material in the circuit and even causing breakdown. Therefore, for the problem of the increase in the resonant frequency caused by capacitor decay, effective early warning and avoidance should be carried out. The embodiment of the present application provides a circuit fault detection method for early warning and avoidance of the circuit resonance problem caused by capacitor decay.

[0055] Figure 1 A circuit fault detection method provided for an exemplary embodiment of the present application, the detection method includes:

[0056] S11. Obtain the inductance value of a preset inductor and determine the capacitance value of a to-be-tested capacitor in a to-be-tested circuit.

[0057] Among them, the inductance value of the preset inductor is a preset value, which is set according to the actual situation.

[0058] In the main circuit, a preset inductor and a to-be-tested circuit provided with a to-be-tested capacitor are included. The preset inductor is connected to the to-be-tested circuit so that the preset inductor and the to-be-tested capacitor form a resonant circuit, and the connection form can be series or parallel.

[0059] As Figure 2 shown, the embodiment of the present application provides a to-be-tested circuit for measuring the capacitance value of a to-be-tested capacitor. In order to improve the accuracy of measuring the to-be-tested capacitor, a pulse signal generator 11, a buffer amplifier 12, a current-limiting resistor R1, and an equivalent circuit resistor R2 are provided in the to-be-tested circuit.

[0060] The non-inverting input terminal of the buffer amplifier 12 is connected to the output terminal of the pulse signal generator 11, and the output terminal of the buffer amplifier 12 is connected to the inverting input terminal of the buffer amplifier 12. A current-limiting resistor R1, an equivalent circuit resistor R2, and a capacitor under test 13 are sequentially connected in series at the output terminal of the buffer amplifier 12.

[0061] Among them, the capacitor under test 13 is composed of a resistor R4 and a capacitor 111 connected in series. Because in practical applications, capacitors are not ideal and they will have some parasitic effects, such as leakage current, lead inductance, and lead resistance. Therefore, in the embodiment of the present application, an ideal resistor R4 and an ideal capacitor 111 are connected in series to form the capacitor under test 13, so that the formed capacitor under test 13 can represent the capacitor in practical applications and more accurately simulate the behavior of the capacitor in the circuit.

[0062] In the series configuration of the current-limiting resistor and the equivalent circuit resistor, the flow of current is jointly restricted, thereby protecting the circuit from overload. However, this configuration may result in a relatively high output impedance, and the current-limiting resistor may introduce additional signal distortion or matching loss, limiting the driving ability. Therefore, the current-limiting resistor and the equivalent circuit resistor can be connected in parallel to reduce the overall equivalent impedance, enabling the buffer amplifier to drive the load more effectively and improving the ability to output current.

[0063] That is, in another embodiment, the current-limiting resistor R1 can also be connected in parallel with the equivalent circuit resistor R2 to form a parallel circuit, and the buffer amplifier 12 sequentially connects the parallel circuit and the capacitor under test 13 in series at the output terminal.

[0064] Based on the pulse signal generator as the signal source, the embodiment of the present application adds a buffer amplifier, which can match the front-end impedance and the back-end impedance of the pulse signal sent by the pulse signal generator, so that the signal output at the output terminal of the buffer amplifier is infinitely close to the input pulse signal, the output signal frequency and voltage are infinitely close to the input pulse signal, maintaining signal integrity, preventing power loss and signal distortion, and ensuring the accuracy of the measurement of the capacitor under test. Since the signal output by the buffer amplifier has a short impact on the circuit under test, the current-limiting resistor can be set to limit the current passing through the capacitor under test and prevent the capacitor under test from being burned out due to excessive current. The equivalent circuit resistor is used to equivalent the resistance of the wire in the circuit under test, which can effectively reduce the influence of the wire resistance on the measurement result, thereby improving the measurement accuracy.

[0065] In addition to the above circuit elements, such as Figure 2 As shown, a first differential amplifier 14, a second differential amplifier 15, a third differential amplifier 16, and a current-detecting resistor R3 are also provided in the circuit under test.

[0066] Among them, the second end of the capacitor 13 to be measured is connected in series to the inverting input terminal of the first differential amplifier 14. The inverting input terminal of the first differential amplifier 14 is also connected in series to the first end of the current detection resistor R3. The non-inverting input terminal of the first differential amplifier 14 is grounded. By equating the output terminal of the first differential amplifier 14 to a virtual ground, a constant reference potential can be maintained, so that even if the value of the current detection resistor R3 changes, it will not affect the current measurement of the entire circuit to be measured. The output terminal of the first differential amplifier 14 is connected to its own inverting input terminal, thus forming a differential operational amplifier with negative feedback. The output terminal of the first differential amplifier 14 is also connected in series to the second end of the current detection resistor R3, thus forming an I / V converter (current-voltage converter) with the current detection resistor R3. By amplifying the voltage change across the current detection resistor R3, the voltage representation of the current signal is achieved, thus realizing the conversion between voltage and current.

[0067] The non-inverting input terminal of the second differential amplifier 15 is connected to the first end of the current detection resistor R3, and the inverting input terminal of the second differential amplifier 15 is connected to the second end of the current detection resistor R3. The non-inverting input terminal and the inverting input terminal of the second differential amplifier 15 are respectively connected in parallel to the first end and the second end of the current detection resistor R3 through an AC coupling unit, which is used to amplify the voltage signals on both sides of the current detection resistor R3. The AC coupling unit consists of a first capacitor 17 and a second capacitor 18. The first capacitor 17 is connected in series to the non-inverting input terminal of the second differential amplifier 15, and the second capacitor 18 is connected in series to the inverting input terminal of the second differential amplifier 15, allowing AC signals to pass through but blocking DC signals, thus achieving the elimination of DC components, reducing interference caused by DC components, and improving the quality and reliability of the signals.

[0068] The non-inverting input terminal of the third differential amplifier 16 is connected to the first end of the capacitor to be measured, and the inverting input terminal of the third differential amplifier 16 is connected to the second end of the capacitor to be measured. The non-inverting input terminal and the inverting input terminal of the third differential amplifier 16 are respectively connected in parallel to the first end and the second end of the capacitor 13 to be measured through an AC coupling unit, which is used to amplify the voltage signals on both sides of the capacitor 13 to be measured. The AC coupling unit consists of a third capacitor 19 and a fourth capacitor 110. The third capacitor 19 is connected in series to the non-inverting input terminal of the third differential amplifier 16, and the fourth capacitor 110 is connected in series to the inverting input terminal of the third differential amplifier 16, allowing AC signals to pass through but blocking DC signals, thus achieving the elimination of DC components, reducing interference caused by DC components, and improving the quality and reliability of the signals.

[0069] Next, based on Figure 2 the circuit to be measured in, a further explanation on how to determine the capacitance value of the capacitor to be measured will be given:

[0070] In one embodiment, a reference signal output by a pulse signal generator may be first obtained through a buffer amplifier 12 and a current-limiting resistor R1, and the frequency of the reference signal may be determined. The reference signal is a pre-set signal, and the form of the reference signal may be a square wave or a sine wave, and may be an analog signal or a digital signal. Then, a first voltage value is obtained by measuring the voltage at the output terminal of the second differential amplifier 15, and a second voltage value is obtained by measuring the voltage at the output terminal of the third differential amplifier 16. Then, according to the first voltage value and the second voltage value, the circuit parameters of the capacitance under test 13 and the phase difference between the circuit parameters and the reference signal are respectively determined. The circuit parameters include at least one of current amplitude, voltage amplitude, voltage, and current, and the phase difference includes the current phase difference between the current of the capacitance under test 13 and the current of the reference signal and / or the voltage phase difference between the voltage of the capacitance under test 13 and the voltage of the reference signal. Then, the impedance of the capacitance under test 13 is determined through the circuit parameters and the phase difference between the circuit parameters and the reference signal. Finally, the capacitance value of the capacitance under test 13 is determined according to the product of the impedance and the frequency of the reference signal.

[0071] First, obtain the pre-set reference signal ① in the circuit under test In the embodiment of the present application, the reference signal is represented by a digital expression form of a sine wave, where u r1 and u r2 are the reference signals, t is the time, then the first voltage value U i and the second voltage value U u can be expressed as ② U DUT and I DUT are the voltage or current excitations generated on the basis of the reference signal, which are the responses generated by the capacitance under test. It can be understood that U DUT is the voltage on the capacitance under test, I DUT is the current on the capacitance under test, U Z is the voltage amplitude, I Z is the current amplitude. is the voltage phase difference between the voltage of the capacitance under test and the voltage of the reference signal. is the current phase difference between the current of the capacitance under test and the current of the reference signal. If the current or voltage of the capacitance under test lags behind the voltage or current of the reference signal, the phase difference is negative.

[0072] Then, multiply Equation ① and Equation ②, and use the sum-to-product formula to obtain ③ Perform the operation of filtering out the second harmonic component (for example, cos(4πf + φ u ) - cosφ u is the sum frequency component, cosφ u is the difference frequency component. Filter out the sum frequency component and retain the difference frequency component), and retain the DC component to obtain where UDUT(t)_1 For U DUT(t) ·u r1(t) 's simplified expression, U DUT(t)_2 is the simplified expression of U DUT(t) ·u r2(t) 's simplified expression, I DUT(t)_1 is the simplified expression of I DUT(t) ·u r1(t) 's simplified expression, I DUT(t)_2 is the simplified expression of I DUT(t) ·u r2(t) 's simplified expression.

[0073] Then, through the above formula, calculate the current amplitude, voltage amplitude, current phase difference, and voltage phase difference of the capacitor to be measured, and obtain Through the current amplitude, voltage amplitude, current phase difference, and voltage phase difference, the modulus and impedance angle of the capacitor to be measured can be calculated. Z DUT is the impedance, and θ is the impedance angle. Then, through the impedance formula Z DUT =R + jX, the real part and imaginary part of the impedance can be obtained where R is the real part of the impedance and X is the imaginary part of the impedance.

[0074] Finally, through the capacitance value C of the capacitor to be measured is obtained now , where f is the frequency of the reference signal.

[0075] In one embodiment, in addition to the above method of calculating the capacitance value through the circuit to be measured, the capacitance value can also be measured using a charge-discharge circuit. By applying a known current-voltage relationship and using the integral relationship between the voltage and current of the capacitor, the capacitance value is measured. The capacitance value C = Q / V, where Q is the electric charge on both sides of the capacitor plates and V is the voltage across the capacitor. Also, since Q = I·t / V, if a constant current source is applied, the capacitance value can be calculated by measuring the change in voltage over time ΔV / Δt. It can be assumed that the constant current is Ic and the rate of change of the measured voltage is dV / dt, then the capacitance value is C = Ic / (dV / dt). A constant current source can be used to charge the capacitor, and the voltage of the capacitor to be measured can be monitored through an ADC (Analog-to-Digital Converter). The controller calibrates the time interval and calculates the capacitance in combination with the known constant current Ic. The related technology is prior art and will not be elaborated here.

[0076] S12. Based on the capacitance value and inductance value, determine the resonant frequency in the circuit to be measured.

[0077] The inductance and capacitance jointly determine the resonant frequency of the circuit. The relationship between capacitance, inductance, and resonant frequency can be expressed as: where f ris the resonant frequency, L is the inductance value, and C is the capacitance value. It can be seen that when the capacitance value remains unchanged, if the inductance value decreases, the resonant frequency will increase because the decrease in the inductance value will lead to a decrease in the inductive reactance, thereby increasing the resonant frequency; when the inductance value remains unchanged, if the capacitance value decreases, the resonant frequency will also increase because the decrease in the capacitance will lead to an increase in the capacitive reactance, thereby increasing the resonant frequency; if the inductance and capacitance increase or decrease simultaneously, the change in the resonant frequency depends on the relative ratio of their changes.

[0078] In Figure 2 the to-be-tested circuit of rnow : where C now is the capacitance value and L is the inductance value.

[0079] S13. In response to the resonant frequency being greater than a preset first threshold, an early warning signal is issued.

[0080] Among them, the early warning signal indicates a fault in the to-be-tested circuit.

[0081] During the operation of the circuit, the capacitance will gradually decay, the capacitance value will decrease, and the resonant frequency will also increase accordingly. If the capacitance value is not within the normal decay range, for example, the capacitance value is less than the normal value, it will cause the resonant frequency to be too high, which may have an adverse impact on the circuit. For example, if the resonant frequency is too high, the current in the circuit may increase sharply. If it exceeds the rated current of the components in the circuit, it may cause the components to overheat and even burn out. Or if the resonant frequency is too high, the resonance phenomenon may cause the voltage in the circuit to exceed the normal operating voltage, thereby damaging the insulating material in the circuit and even causing breakdown.

[0082] In order to timely determine whether the capacitance value is within the normal decay range, taking a vehicle as an example, the components in the to-be-tested circuit of the vehicle can be started each time the vehicle starts and powers on the high-voltage electricity to measure the capacitance value. Or when the main circuit in the vehicle is working, the capacitance value can be detected and calculated in real time through the components in the to-be-tested circuit of the main circuit. Or based on the 5-year lifespan of the capacitor, an empirical value of once every 15 days can be selected to measure the capacitance value.

[0083] As shown above, after determining the capacitance value at regular intervals, the resonant frequency can be determined based on the capacitance value and the inductance value. Then, it is judged whether the resonant frequency is greater than a preset first threshold value. The first threshold value can be set as the resonant frequency of the circuit under test when the capacitance value of the capacitance to be measured is the preset capacitance value. For example, when the capacitance value decays to 50% of the rated capacitance value, it is regarded as scrapped. Then the preset capacitance value can be 50% of the rated capacitance value, and the first threshold value is the resonant frequency of the capacitance to be measured with 50% of the rated capacitance value and the nominal inductance. At this time, the resonant frequency is relatively high and may affect the normal operation of the circuit. The first threshold value can be 10 kHz or 11 kHz.

[0084] If the resonant frequency is greater than the preset first threshold value, it indicates that the resonant frequency is too high and may have an adverse impact on the circuit. An early warning signal needs to be sent for early warning to reduce the circuit problems caused by capacitance decay.

[0085] Taking a vehicle as an example, if the resonant frequency in the main circuit of the vehicle is greater than the preset first threshold value, after sending an early warning, measures can be taken that except for the drive motor and the DCDC electrical appliance (DC-to-DC Converter) in the main circuit working normally, other high-voltage components work at half load, and the time interval for detecting the capacitance value of the capacitance to be measured is changed to once every 20 minutes, which can effectively reduce the damage to the vehicle caused by the circuit problems brought about by capacitance decay.

[0086] In order to achieve the accuracy of early warning of the resonant frequency, which helps to identify and early warn of resonant frequency risks at different levels, so as to take appropriate preventive measures. In one embodiment, in response to the resonant frequency being greater than the preset first threshold value, sending an early warning signal includes:

[0087] In response to the capacitance to be measured being the preset capacitance value, determining the first resonant frequency of the circuit under test and the first threshold value corresponding to the first resonant frequency;

[0088] In response to the capacitance to be measured being the rated capacitance value, determining the second resonant frequency of the circuit under test and the second threshold value corresponding to the second resonant frequency;

[0089] In response to the resonant frequency being between the first threshold value and the preset second threshold value, sending a first early warning signal;

[0090] In response to the resonant frequency being greater than or equal to the first threshold value, or the resonant frequency being less than or equal to the second threshold value, sending a second early warning signal.

[0091] Among them, the first threshold can be set as the first resonant frequency of the circuit under test when the capacitance to be measured is the preset capacitance value. For example, when the capacitance value decays to 50% of the rated capacitance value, it is regarded as scrapped. Then the preset capacitance value can be 50% of the rated capacitance value, and the first threshold is the resonant frequency under the capacitance to be measured of 50% of the rated capacitance value and the nominal inductance. At this time, the resonant frequency is relatively high, which may affect the normal operation of the circuit. The first threshold can be 10 kHz or 11 kHz.

[0092] The second threshold is set as the second resonant frequency of the circuit under test when the capacitance to be measured is the rated capacitance value. For example, the second threshold is the resonant frequency under the capacitance to be measured with 100% life and the nominal inductance. At this time, the resonant frequency is the lowest and can be 5 kHz or 6 kHz.

[0093] The main circuit includes the circuit under test and a preset inductor. If the resonant frequency is too high, the current in the main circuit may increase sharply. If it exceeds the rated current of the components in the main circuit, it may cause the components to overheat or even burn out. Or if the resonant frequency is too high, the resonance phenomenon may cause the voltage in the main circuit to exceed the normal operating voltage, thereby damaging the insulating materials in the circuit and even causing breakdown. And if the resonant frequency is too small, it will also cause the inductor and capacitor components in the main circuit to resonate at a specific frequency, generating voltages and currents several times higher than the power supply. The overvoltage and overcurrent may damage equipment such as capacitors, current transformers, and circuit breakers in the circuit, and even cause equipment explosion. Therefore, if the resonant frequency is less than the preset second threshold, it indicates that the resonant frequency is too low and may have an adverse impact on the circuit, and a warning signal needs to be issued for warning.

[0094] If the resonant frequency is between the first threshold and the preset second threshold, it is determined that the attenuation of the capacitance value is less, and a first warning signal can be issued. Taking a vehicle as an example, if the resonant frequency in the main circuit of the vehicle is between the first threshold and the preset second threshold, a first warning signal is issued. Measures can be taken that the vehicle does not need to be processed, and only the time interval for measuring the capacitance to be measured is changed to measure once when the vehicle is powered on and off.

[0095] If the resonant frequency is greater than or equal to the first threshold, or the resonant frequency is less than or equal to the second threshold, it is determined that the resonant frequency may have an impact on the main circuit, and a second warning signal can be issued. Taking a vehicle as an example, if the resonant frequency in the main circuit of the vehicle is greater than or equal to the first threshold, or less than or equal to the first threshold, a second warning signal is issued. Measures can be taken that except for the driving motor and DCDC electrical appliances (DC-to-DC Converter) in the main circuit operating normally, other high-voltage components operate at half load, and the time interval for detecting the capacitance value of the capacitance to be measured is changed to detect once every 20 minutes, which can effectively reduce the damage to the vehicle caused by circuit problems brought about by capacitance attenuation.

[0096] From the formula it can be seen that the attenuation of the capacitance value of the capacitance to be measured will not only cause the resonance frequency in the main circuit to be abnormal, but also increase the ripple current, resulting in a poor filtering effect. Among them, ΔI is the ripple current, V in is the input voltage of the main circuit, f s is the switching frequency of the MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) in the main circuit, D is the duty cycle of the PWM wave, L is the inductance value, and C is the capacitance value. Therefore, in order to reduce the influence of the ripple current on the main circuit and avoid the deterioration of the filtering effect of the main circuit, in one embodiment, in response to the resonance frequency being greater than a preset first threshold, a warning signal is issued, and it further includes:

[0097] In response to the resonance frequency being greater than a preset first threshold, obtain the current signal of the capacitance to be measured;

[0098] Based on the peak-to-peak value or the effective value of the current signal, determine the ripple current of the circuit to be measured;

[0099] In response to the ripple current being greater than a preset third threshold, issue a third warning signal and adjust the current value of the circuit to be measured to a preset current value.

[0100] The third threshold is a preset value, which can be set by itself according to the actual situation. For example, it is 60A or 65A.

[0101] When the resonance frequency is greater than the preset first threshold, it means that the resonance frequency is too high, which may have an adverse effect on the circuit and also increase the ripple current, resulting in a poor filtering effect. At this time, a third warning signal is issued. A current sensor, such as a Hall effect sensor, can be set in the main circuit to monitor the current waveform in the circuit in real time, and then an ADC analog-to-digital converter is set to convert the analog signal into a digital signal and upload it to the controller for processing.

[0102] Exemplarily, referring to Figure 3 , a Hall effect sensor 31 and an ADC analog-to-digital converter 38 are set in the main circuit.

[0103] Among them, the Hall effect sensor 31 includes a current input pin IP+ and IP-, IP+ is the forward current input pin, IP- is the reverse current input pin, and the current input pins IP+ and IP- are used to connect the main circuit to receive the current transmitted by the main circuit.

[0104] The Hall effect sensor 31 further includes a voltage output pin VIOUT and a filter pin FILTER. The voltage output pin VIOUT is the analog signal output terminal of the Hall effect sensor, and is used to output an analog voltage signal proportional to the input magnetic field strength or current. The filter pin FILTER is usually used to externally connect a filter capacitor, which forms an RC low-pass filter with a resistor to suppress high-frequency noise (such as switching power supply noise and electromagnetic interference).

[0105] The RC low-pass filter 32 is usually (resistor-capacitor low-pass filter) composed of a first resistor 33 and a first capacitor 34 connected in series. The voltage output pin VIOUT is connected to one end of the first resistor 33, that is, the input terminal of the RC low-pass filter 32, to input an analog voltage signal to the RC low-pass filter. The other end of the first resistor 33 is the output terminal of the RC low-pass filter 32. The filter pin FILTER is connected to one end of the first capacitor 34, and the other end of the first capacitor 34 is grounded.

[0106] A register 36 and an ADC analog-to-digital converter 38 are connected in series in sequence at the output terminal of the RC low-pass filter 32. The ADC analog-to-digital converter 38 is used to convert the input analog signal into a digital signal, and the register 36 is used to store the analog signal before conversion and the digital signal after conversion by the ADC analog-to-digital converter 38.

[0107] In order to avoid the voltage of the signal filtered by the RC low-pass filter 32 being too large and not meeting the signal input requirements of the input ADC analog-to-digital converter 38, a second resistor 35 can also be connected in series between the first resistor 33 and the first capacitor 34, and the excessive voltage can be divided by the second resistor 35.

[0108] Moreover, a first connection point can be set between the connection line of the register 36 and the ADC analog-to-digital converter 38, a second connection point can be set between the connection line of the first capacitor 34 and the second resistor 35, and a third capacitor 37 can be set between the first connection point and the second connection point to keep the voltage in the circuit stable.

[0109] In addition, the Hall effect sensor 31 further includes a power input pin VCC and a ground pin GND. The power input pin VCC is used to connect to the positive pole of the power supply U1, and U1 can provide the required electrical energy for the normal operation of the Hall effect sensor 31. Since the voltage output by the power supply U1 may be unstable, a connection point can also be set between the connection line of the power input pin VCC and the power supply U1, and the second capacitor 39 is connected to the ground wire GND1 through the connection point, thereby improving the voltage stability in the circuit and the signal quality of the Hall effect sensor 31. The ground pin GND is used to connect to the ground wire GND2 (ground) of the circuit, providing an electrical reference zero potential for the sensor, ensuring that the potentials of all points in the circuit have a unified reference, and is also part of the current loop.

[0110] For example, the ripple current is usually expressed in peak-to-peak value because it describes the full range of current fluctuations. The current signal can be digitally filtered to extract and calculate the peak-to-peak value or the effective value of the current, and the ripple current can be determined through the peak-to-peak value or the effective value. Given the waveform of the current signal, the magnitude of the ripple current can be directly determined by measuring the peak-to-peak value or the effective value of the current signal. Taking a sine wave as an example, through the peak-to-peak value ΔI = Imax - Imin or the effective value the ripple current ΔI is determined, and then the ripple current ΔI is compared with a preset third threshold I ripple，threshold If ΔI > I ripple，threshold , a third warning signal is issued, and the current value of the main circuit is adjusted to the preset current value to reduce the output voltage fluctuation of the main circuit caused by excessive ripple current, thereby improving the stability and reliability of the main circuit, reducing electromagnetic interference, and prolonging the service life of the main circuit.

[0111] In one embodiment, taking an automobile as an example, when the ripple current is greater than the preset third threshold and after the third warning signal is issued, the acceleration of the vehicle can also be reduced to the preset acceleration to obtain a lower input voltage Vin, thereby adjusting the current value of the main circuit to the preset current value. For example, the input voltage of the main circuit of the vehicle is 400V or 800V, the initial vehicle speed is 90km / h, the acceleration is 0.8g, the power output is 120kw, and the current is 300A. When the ripple current is greater than the preset third threshold and the third warning signal is issued, keeping the voltage unchanged and obtaining a low-value input current to adjust the current value of the main circuit to the preset current value, the vehicle speed can be reduced to below 30km / h, and the vehicle acceleration is less than 0.2g, the output power is 60kw, then the current is 150A, and the third warning signal is transmitted to the vehicle operator to indicate that maintenance or replacement of the filter capacitor is required at this time.

[0112] It is also possible to obtain the resonant frequency corresponding to the entire life cycle of the capacitor to be measured in the main circuit of the vehicle through vehicle calibration, and then make a state table SOH-fs table (State of Health-Full Scale), compare it with the working circuit frequencies under different working conditions, divide the frequency bands prone to resonance or calibrate the frequency bands that will generate resonance, and at the same time record the SOH corresponding to this frequency band and set it as the risk threshold for alarm.

[0113] When the ripple current is greater than a preset third threshold, in addition to the above intervention measures, a set of spare filter capacitors can also be added to the main circuit. When the capacitor under test decays or fails, it is switched to the spare filter capacitor through a relay or semiconductor switch in the main circuit, which can also be called a standby capacitor. For example, multiple filter capacitor groups (the capacitor under test and the standby capacitor) are connected in parallel in the main circuit in advance. When the Hall sensor monitors that the attenuation of the capacitor under test causes an increase in the ripple current, the controller triggers a control signal to turn on the standby capacitor switch, switch to the standby capacitor, and at the same time remove the capacitor under test from the main circuit.

[0114] Alternatively, the switching frequency of the switching device in the main circuit, such as a MOSFET, can also be adjusted. The microcontroller adjusts the switching frequency of the PWM signal according to the ripple current value obtained by the Hall sensor and the ADC digital-to-analog converter, and limits the ripple current below the preset third threshold to avoid the deterioration of the filtering effect caused by the increase in the ripple current.

[0115] Alternatively, the duty cycle of the PWM wave in the main circuit can also be adjusted. By designing an adaptive controller in the main circuit and using the PID (Proportional Integral Derivative) algorithm to adjust the duty cycle of the PWM signal in real time, the ripple current can be limited below the preset third threshold to avoid the deterioration of the filtering effect caused by the increase in the ripple current.

[0116] It should be understood that although Figure 1 the steps in the flowchart of Figure 1 are shown in sequence according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise clearly stated in this article, there is no strict order limit for the execution of these steps, and these steps can be executed in other orders. Moreover,

[0117] As Figure 4 shown, the present application also provides a circuit fault detection system. The detection system includes:

[0118] A first determination module 41, configured to obtain the inductance value of a preset inductor and determine the capacitance value of a capacitor under test in a circuit under test; the preset inductor is connected to the circuit under test;

[0119] A second determination module 42, configured to determine the resonance frequency in the circuit under test based on the capacitance value and the inductance value;

[0120] An early warning module 43, configured to issue an early warning signal in response to the resonance frequency being greater than a preset first threshold; the early warning signal indicates a fault in the circuit under test.

[0121] Optionally, the circuit under test further includes a pulse signal generator, a buffer amplifier, a current limiting resistor, and an equivalent circuit resistor; wherein,

[0122] The non-inverting input terminal of the buffer amplifier is connected to the output terminal of the pulse signal generator,

[0123] The output terminal of the buffer amplifier is connected to the inverting input terminal of the buffer amplifier and is also connected to the first end of the current limiting resistor;

[0124] The second end of the current limiting resistor is connected to the first end of the equivalent circuit resistor;

[0125] The second end of the equivalent circuit resistor is connected to the first end of the capacitor under test.

[0126] In one embodiment, the first end of the current detection resistor is connected to the second end of the capacitor under test, the non-inverting input terminal of the second differential amplifier is connected to the first end of the current detection resistor, the inverting input terminal of the second differential amplifier is connected to the second end of the current detection resistor, the non-inverting input terminal of the third differential amplifier is connected to the first end of the capacitor under test, and the inverting input terminal of the third differential amplifier is connected to the second end of the capacitor under test;

[0127] Then the first determination module 41 is further configured to:

[0128] Measure the reference signal output by the pulse signal generator and determine the frequency of the reference signal;

[0129] Determine the first voltage value output by the first differential amplifier and determine the second voltage value output by the second differential amplifier;

[0130] Based on the first voltage value and the second voltage value, respectively determine the circuit parameters of the capacitor under test and the phase difference between the circuit parameters and the reference signal; the circuit parameters include at least one of current amplitude, voltage amplitude, voltage, and current, and the phase difference includes current phase difference and / or voltage phase difference;

[0131] Based on the circuit parameters and the phase difference, determine the impedance of the capacitor under test;

[0132] Based on the product of the impedance and the frequency of the reference signal, determine the capacitance value of the capacitor under test.

[0133] In one embodiment, the early warning module 43 is further configured to:

[0134] When the capacitance to be measured is a preset capacitance value, determine a first resonance frequency of the circuit to be measured and a first threshold value corresponding to the first resonance frequency;

[0135] When the capacitance to be measured is a rated capacitance value, determine a second resonance frequency of the circuit to be measured and a second threshold value corresponding to the second resonance frequency;

[0136] When the resonance frequency is between the first threshold value and the second threshold value, send a first warning signal;

[0137] When the resonance frequency is greater than or equal to the first threshold value, or the resonance frequency is less than or equal to the second threshold value, send a second warning signal.

[0138] In one embodiment, the warning module 43 is further configured to:

[0139] The step of sending a warning signal when the resonance frequency is greater than a preset first threshold value includes:

[0140] When the resonance frequency is greater than a preset first threshold value, obtain a current signal of the capacitance to be measured;

[0141] Based on the peak-to-peak value or the effective value of the current signal, determine the ripple current of the circuit to be measured;

[0142] When the ripple current is greater than a preset third threshold value, send a third warning signal.

[0143] In one embodiment, the detection system further includes a speed reduction module, configured to:

[0144] Reduce the acceleration of the vehicle to a preset acceleration.

[0145] For the system embodiment, since it basically corresponds to the method embodiment, the relevant parts can refer to the partial description of the method embodiment. The system embodiments described above are only illustrative. The units described as separate components may or may not be physically separated. The components as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of the present application.

[0146] Figure 5 FIG. is a schematic structural diagram of an electronic device according to an exemplary embodiment of the present application. The electronic device includes a memory, a processor, and a computer program stored on the memory and configured to run on the processor. When the processor executes the computer program, the circuit fault detection method described in any of the above embodiments is implemented. Figure 5The displayed electronic device 50 is merely an example and shall not impose any limitation on the functions and scope of use of the embodiments of the present application.

[0147] As Figure 5 shown, the electronic device 50 may be presented in the form of a general-purpose computing device. For example, it may be a server device. The components of the electronic device 50 may include, but are not limited to: the at least one processor 51 described above, the at least one memory 52 described above, and a bus 53 connecting different system components (including the memory 52 and the processor 51).

[0148] The bus 53 includes a data bus, an address bus, and a control bus.

[0149] The memory 52 may include volatile memory, such as a random access memory (RAM) 521 and / or a cache memory 522, and may further include a read-only memory (ROM) 523.

[0150] The memory 52 may also include a program tool 525 (or utility) having a set of (at least one) program modules 524. Such program modules 524 include, but are not limited to: an operating system, one or more application programs, other program modules, and program data. Each or some combination of these examples may include the implementation of a network environment.

[0151] The processor 51 executes various functional applications and data processing by running computer programs stored in the memory 52, such as the circuit fault detection method provided in any of the above embodiments.

[0152] The electronic device 50 may also communicate with one or more external devices 54 (such as a keyboard, a pointing device, etc.). Such communication may be carried out through an input / output (I / O) interface 55. And, the electronic device 50 may also communicate with one or more networks (such as a local area network (LAN), a wide area network (WAN), and / or a public network, such as the Internet) through a network adapter 56. As shown in the figure, the network adapter 56 communicates with other modules of the electronic device 50 through the bus 53. It should be understood that although not shown in the figure, other hardware and / or software modules may be used in combination with the electronic device 50, including but not limited to: microcode, device drivers, redundant processors, external disk drive arrays, RAID (disk array) systems, tape drives, and data backup storage systems, etc.

[0153] It should be noted that although several units / modules or sub-units / modules of the electronic device are mentioned in the above detailed description, this division is merely exemplary and not mandatory. In fact, according to the embodiments of the present application, the features and functions of two or more units / modules described above can be embodied in one unit / modules. Conversely, the features and functions of one unit / modules described above can be further divided and embodied by multiple units / modules.

[0154] The embodiments of the present application also provide a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, it implements the circuit fault detection method provided in any one of the above embodiments.

[0155] Among them, the more specific forms that the readable storage medium can adopt may include but are not limited to: portable disks, hard disks, random access memories, read-only memories, erasable programmable read-only memories, optical storage devices, magnetic storage devices, or any suitable combination of the above.

[0156] Those of ordinary skill in the art can understand that all or part of the processes of implementing the methods in the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, storage, database, or other medium used in the embodiments provided by the present application can include non-volatile and / or volatile memories. Non-volatile memories can include read-only memories (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memories. Volatile memories can include random access memories (RAM) or external cache memories. By way of illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0157] The embodiments of the present application also provide a computer program product, including a computer program, and when the computer program is executed by a processor, it implements the circuit fault detection method described in any one of the above.

[0158] Among them, the program code for executing the computer program product of the present application can be written in any combination of one or more programming languages, and the program code can be executed entirely on the user device, partially on the user device, executed as an independent software package, partially on the user device and partially on a remote device, or entirely on a remote device.

[0159] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0160] The above-described embodiments merely represent several implementation manners of the present application, and the description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. A circuit fault detection method, characterized in that, The detection method includes: Obtaining the inductance value of a preset inductor and determining the capacitance value of a capacitance under test in a circuit under test; the preset inductor is connected to the circuit under test; Determining the resonance frequency in the circuit under test based on the capacitance value and the inductance value; In response to the resonance frequency being greater than a preset first threshold, sending out a warning signal; the warning signal indicates a fault in the circuit under test.

2. The detection method according to claim 1, wherein The circuit under test further includes a pulse signal generator, a buffer amplifier, a current-limiting resistor, and an equivalent circuit resistor; wherein, The non-inverting input terminal of the buffer amplifier is connected to the output terminal of the pulse signal generator, The output terminal of the buffer amplifier is connected to the inverting input terminal of the buffer amplifier and is connected to the first end of the current-limiting resistor; The second end of the current-limiting resistor is connected to the first end of the equivalent circuit resistor; The second end of the equivalent circuit resistor is connected to the first end of the capacitance under test.

3. The detection method according to claim 2, wherein The first end of a current detection resistor is connected to the second end of the capacitance under test, the non-inverting input terminal of a second differential amplifier is connected to the first end of the current detection resistor, the inverting input terminal of the second differential amplifier is connected to the second end of the current detection resistor, the non-inverting input terminal of a third differential amplifier is connected to the first end of the capacitance under test, and the inverting input terminal of the third differential amplifier is connected to the second end of the capacitance under test; Then the determining the capacitance value of the capacitance under test in the circuit under test includes: Measuring a reference signal output by the pulse signal generator and determining the frequency of the reference signal; Determining a first voltage value output by the first differential amplifier and determining a second voltage value output by the second differential amplifier; Based on the first voltage value and the second voltage value, respectively determining the circuit parameters of the capacitance under test and the phase difference between the circuit parameters and the reference signal; the circuit parameters include at least one of current amplitude, voltage amplitude, voltage, and current, and the phase difference includes current phase difference and / or voltage phase difference; Determining the impedance of the capacitance under test based on the circuit parameters and the phase difference; Determining the capacitance value of the capacitance under test based on the product of the impedance and the frequency of the reference signal.

4. The detection method according to claim 1, characterized in that, The in response to the resonance frequency being greater than a preset first threshold, sending out a warning signal includes: In response to the capacitance under test being a preset capacitance value, determining a first resonance frequency of the circuit under test and a first threshold corresponding to the first resonance frequency; In response to the capacitance under test being a rated capacitance value, determining a second resonance frequency of the circuit under test and a second threshold corresponding to the second resonance frequency; In response to the resonance frequency being between the first threshold and the second threshold, sending out a first warning signal; In response to the resonance frequency being greater than or equal to the first threshold, or the resonance frequency being less than or equal to the second threshold, sending out a second warning signal.

5. The detection method according to any one of claims 1-4, characterized in that, The in response to the resonance frequency being greater than a preset first threshold, sending out a warning signal includes: In response to the resonance frequency being greater than a preset first threshold, obtaining a current signal of the capacitance under test; Determining the ripple current of the circuit under test based on the peak-to-peak value or the effective value of the current signal; In response to the ripple current being greater than a preset third threshold, a third warning signal is issued.

6. The detection method according to claim 5, characterized in that, The detection method is applied to a vehicle. After issuing the third warning signal in response to the ripple current being greater than the preset third threshold, it further includes: Reducing the acceleration of the vehicle to a preset acceleration.

7. A circuit fault detection system, characterized in that The detection system includes: A first determination module for obtaining the inductance value of a preset inductor and determining the capacitance value of a capacitor under test in a circuit under test; the preset inductor is connected to the circuit under test; A second determination module for determining the resonance frequency in the circuit under test based on the capacitance value and the inductance value; A warning module for issuing a warning signal in response to the resonance frequency being greater than a preset first threshold; the warning signal indicates a fault in the circuit under test.

8. An electronic device, comprising a memory, a processor, and a computer program stored on the memory and configured to run on the processor, characterized in that, When the processor executes the computer program, the detection method according to any one of claims 1 to 6 is implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, the detection method according to any one of claims 1 to 6 is implemented.

10. A computer program product comprising a computer program, characterized in that, When the computer program is executed by a processor, the detection method according to any one of claims 1 to 6 is implemented.

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