Capacitor health degree detection method and device

Abstract

The invention discloses a capacitor health degree detection method and equipment, and the method comprises the steps: applying a sine wave test signal to a to-be-detected capacitor, obtaining a current signal and a voltage signal of the to-be-detected capacitor, calculating the phase angle of the to-be-detected capacitor through the current signal and the voltage signal, calculating the equivalent series resistance and capacitive reactance of the to-be-detected capacitor based on the phase angle, and obtaining the health degree of the to-be-detected capacitor. And calculating the capacitance of the to-be-measured capacitor based on the capacitive reactance, calculating the loss tangent value of the to-be-measured capacitor according to the equivalent series resistance and the capacitive reactance, and predicting the health degree of the capacitor according to the equivalent series resistance, the capacitance value and the change of the loss tangent value. Therefore, when the capacitor operates normally, current and voltage signals of the capacitor can be measured actively, and the health degree of the capacitor can be calculated by combining the equivalent series resistance, the capacity and the loss tangent value of the capacitor, so that the health condition of the capacitor can be evaluated more accurately and comprehensively, and early warning and troubleshooting can be carried out on the abnormal capacitor as soon as possible.

Description

Technical Field

[0001] This application relates to the field of capacitance testing, and more specifically, to a method and apparatus for testing the health of capacitance. Background Technology

[0002] In the field of capacitor testing, current mainstream testing methods suffer from significant lag, making it difficult to support accurate calculations of capacitor health status. Existing technologies largely rely on post-failure diagnosis or manual visual inspection. For example, the voltage threshold method only triggers an alarm when the capacitor has irreversibly failed, and visual inspection requires disassembling the motherboard to observe external features such as bulging and leakage. However, these methods cannot effectively identify early degradation phenomena, resulting in the inability to obtain the early status data needed for health status calculations. Furthermore, post-failure repairs can easily cause irreversible problems such as damage to printed circuit board pads, further affecting the completeness of capacitor health status assessments.

[0003] In addition, the industry lacks a unified standard for measuring capacitor health. Different manufacturers have different definitions of health, and cross-platform data is not comparable, resulting in no unified benchmark for health calculation.

[0004] Therefore, how to proactively and more accurately assess the health of capacitors and conduct early warnings and investigations of abnormal capacitors are issues that need attention. Summary of the Invention

[0005] In view of the above problems, this application provides a capacitor health detection method and device to proactively and more accurately assess the health of capacitors and to conduct early warning and investigation of abnormal capacitors.

[0006] To achieve the above objectives, the following specific solutions are proposed:

[0007] A method for detecting capacitance health, applied to a capacitance health detection device, the method comprising:

[0008] By applying a sinusoidal test signal to the capacitor under test, the current and voltage signals of the capacitor under test are obtained.

[0009] The phase angle and impedance of the capacitor under test are calculated using the current signal and the voltage signal.

[0010] Based on the phase angle and the impedance, the equivalent series resistance and capacitive reactance of the capacitor under test are calculated, and the capacitance of the capacitor under test is calculated based on the capacitive reactance.

[0011] Calculate the loss tangent of the capacitor under test based on the equivalent series resistance and the capacitive reactance.

[0012] The health status of the capacitor under test is calculated based on the equivalent series resistance, the capacitance, and the loss tangent.

[0013] Optionally, the health of the capacitor under test is calculated based on the equivalent series resistance, the capacitance, and the loss tangent, including:

[0014] The health status of the capacitor under test is calculated using the following formula:

[0015]

[0016] in, The equivalent series resistance is given. For the capacity, The loss angle tangent value is... The equivalent series resistance is measured during the initial use of the capacitor under test. The capacitance measured during the initial use of the capacitor under test. The value is the loss tangent measured during the initial use of the capacitor under test. This is the weighting factor for the equivalent series resistance. This is the capacity weighting coefficient. The weighting coefficient is the tangent of the loss angle. .

[0017] Optionally, the method further includes:

[0018] The current signal and the voltage signal are input into a pre-established capacitor health prediction model, and the health status of the capacitor under test is output.

[0019] The process of establishing the capacitor health prediction model includes:

[0020] Acquire training sample data, which includes the type, brand, usage time, and degradation data of each type of capacitor;

[0021] The regression model is trained using the training sample data to adjust the equivalent series resistance weight coefficient, the capacity weight coefficient, and the loss tangent weight coefficient used to calculate the capacitor health in the regression model, thereby obtaining a capacitor health prediction model.

[0022] Optionally, the acquisition circuit of the capacitor health detection device includes a sine wave generator, a current-to-voltage conversion circuit, an analog-to-digital converter, and a phase detection circuit.

[0023] Optionally, the capacitance health detection device includes two probes and a host unit. The host unit is connected to the two probes, the acquisition circuit is integrated into the probes, and the host unit houses the processing circuit of the capacitance health detection device.

[0024] Optionally, the capacitance health testing device includes two probes, and all circuitry of the device is integrated into the handles of the probes.

[0025] Optionally, the probes are connected in a four-wire Kelvin configuration for detection.

[0026] Optionally, the capacitor health testing device includes a display screen for displaying the test results of the capacitor under test.

[0027] Optionally, the capacitance health detection device further includes a Bluetooth module, and the method further includes:

[0028] The Bluetooth module sends the test results of the capacitor under test to the terminal.

[0029] A capacitor health testing device includes current and voltage test leads and an MCU (Microcontroller Unit). The MCU includes a phase angle and impedance calculation unit, an equivalent series resistance and capacitive reactance calculation unit, a capacitance calculation unit, a loss tangent calculation unit, and a health calculation unit.

[0030] The current and voltage test probes are used to obtain the current and voltage signals of the capacitor under test by applying a sinusoidal test signal to the capacitor under test.

[0031] The phase angle and impedance calculation unit is used to calculate the phase angle and impedance of the capacitor under test using the current signal and the voltage signal.

[0032] The equivalent series resistance and capacitive reactance calculation unit is used to calculate the equivalent series resistance and capacitive reactance of the capacitor under test based on the phase angle and the impedance.

[0033] The capacity calculation unit is used to calculate the capacity of the capacitor under test based on the capacitive reactance;

[0034] The loss tangent calculation unit is used to calculate the loss tangent of the capacitor under test based on the equivalent series resistance and the capacitive reactance.

[0035] The health calculation unit is used to calculate the health of the capacitor under test based on the equivalent series resistance, the capacitance, and the loss tangent.

[0036] Optionally, the health calculation unit includes:

[0037] The health calculation subunit is used to calculate the health of the capacitor under test using the following formula:

[0038]

[0039] in, The equivalent series resistance is given. For the capacity, The loss angle tangent value is... The equivalent series resistance is measured during the initial use of the capacitor under test. The capacitance measured during the initial use of the capacitor under test. The value is the loss tangent measured during the initial use of the capacitor under test. This is the weighting factor for the equivalent series resistance. This is the capacity weighting coefficient. The weighting coefficient is the tangent of the loss angle. .

[0040] Optionally, the capacitor health testing device may also include:

[0041] The health prediction unit is used to input the current signal and the voltage signal into a pre-established capacitor health prediction model and output the health of the capacitor under test.

[0042] The process of establishing the capacitor health prediction model includes:

[0043] Acquire training sample data, which includes the type, brand, usage time, and degradation data of each type of capacitor;

[0044] The regression model is trained using the training sample data to adjust the equivalent series resistance weight coefficient, the capacity weight coefficient, and the loss tangent weight coefficient used to calculate the capacitor health in the regression model, thereby obtaining a capacitor health prediction model.

[0045] Optionally, the acquisition circuit of the capacitor health detection device includes a sine wave generator, a current-to-voltage conversion circuit, an analog-to-digital converter, and a phase detection circuit.

[0046] Optionally, the capacitance health detection device includes two probes and a host unit. The host unit is connected to the two probes, the acquisition circuit is integrated into the probes, and the host unit houses the processing circuit of the capacitance health detection device.

[0047] Optionally, the capacitance health testing device includes two probes, and all circuitry of the device is integrated into the handles of the probes.

[0048] Optionally, the probes are connected in a four-wire Kelvin configuration for detection.

[0049] Optionally, the capacitor health testing device includes a display screen for displaying the test results of the capacitor under test.

[0050] Optionally, the capacitance health detection device further includes a Bluetooth module, and the capacitance health detection device also includes:

[0051] The transmitting unit is used to transmit the index detection results of the capacitor under test to the terminal via the Bluetooth module.

[0052] By employing the above technical solution, this application obtains the current and voltage signals of the capacitor under test by applying a sinusoidal test signal. The phase angle of the capacitor under test is calculated using the current and voltage signals. Based on the phase angle, the equivalent series resistance and capacitive reactance of the capacitor under test are calculated. The capacitance of the capacitor under test is then calculated based on the capacitive reactance. The loss tangent of the capacitor under test is calculated based on the equivalent series resistance and the capacitive reactance. The capacitor's health is predicted based on the changes in the equivalent series resistance, capacitance, and loss tangent. Therefore, during normal operation, the current and voltage signals of the capacitor can be actively measured, and the health of the capacitor can be calculated by combining the equivalent series resistance, capacitance, and loss tangent. This allows for a more accurate and comprehensive assessment of the capacitor's health, enabling early warning and troubleshooting of abnormal capacitors. Attached Figure Description

[0053] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0054] Figure 1 This is a schematic diagram of a process for implementing capacitor health detection provided in an embodiment of this application;

[0055] Figure 2 A schematic diagram of a single probe of a capacitance health testing device provided in an embodiment of this application;

[0056] Figure 3 This is a schematic diagram of a motherboard for a capacitor health detection device provided in an embodiment of this application;

[0057] Figure 4 A schematic diagram of a circuit principle for a four-wire resistance measurement method provided in an embodiment of this application;

[0058] Figure 5 This is a schematic diagram of the structure of a device for detecting capacitor health according to an embodiment of this application. Detailed Implementation

[0059] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0060] The proposed solution can be implemented based on a terminal with data processing capabilities, which can be a capacitor health detection device.

[0061] Next, combined Figure 1 The capacitance health detection method of this application may include the following steps:

[0062] Step S110: Obtain the current signal and voltage signal of the capacitor under test by applying a sinusoidal test signal to the capacitor under test.

[0063] Specifically, the VI conversion method (vector voltage method) can be used to generate a sinusoidal test signal of a specific frequency (100Hz, 1kHz / 10kHz) and apply it to the capacitor under test to obtain current and voltage signals.

[0064] Step S120: Calculate the phase angle and impedance of the capacitor under test using the current signal and voltage signal.

[0065] Specifically, the phase angle of the capacitor under test is the phase difference between the voltage waveform and the current waveform, and the impedance of the capacitor under test is the ratio of the root mean square value of the AC voltage signal to the root mean square value of the AC current signal.

[0066] Step S130: Based on the phase angle and impedance, calculate the equivalent series resistance and capacitive reactance of the capacitor under test, and calculate the capacitance of the capacitor under test based on the capacitive reactance.

[0067] Specifically, the equivalent series resistance of the capacitor under test is the product of the impedance and the cosine of the phase angle, the capacitive reactance of the capacitor under test is the product of the impedance and the sine of the phase angle, and the capacitance of the capacitor under test is C = 1 / (2*π*f*Xc), where f is the frequency of the sinusoidal test signal applied to the capacitor under test, and Xc is the capacitive reactance.

[0068] It is understandable that the equivalent series resistance (ESR) is related to the electrodes. The metal electrodes of a capacitor themselves have metallic resistance, and the contact interface between the electrodes and the electrolyte / dielectric will generate contact resistance due to the physical contact characteristics between the materials, which is an important component of the ESR. The ESR is also related to the electrolyte / dielectric. For electrolytic capacitors, the internal liquid electrolyte has a certain degree of conductivity, resulting in electrolyte resistance; for multilayer ceramic capacitors, the ceramic dielectric exhibits ionic conductivity under the influence of an electric field, resulting in dielectric leakage resistance. These resistances caused by the physical properties of the dielectric / electrolyte materials directly contribute to the formation of the ESR. Therefore, the ESR can reflect the degradation of internal materials. The ESR of an electrolytic capacitor is mainly determined by the ionic conductivity of the electrolyte and the quality of the electrode oxide film. During the aging of an electrolytic capacitor, electrolyte drying or electrode corrosion leads to increased ion migration resistance, resulting in a significant increase in the ESR.

[0069] At the same voltage, a larger capacitance can store more charge; conversely, a smaller capacitance stores less charge. For example, a 1μF capacitor at 5V stores far less charge than a 100μF capacitor at the same voltage. Capacitance directly affects the charging and discharging speed of a capacitor: in the same charging and discharging circuit, a larger capacitance takes longer to reach the target voltage during charging and releases charge more slowly during discharging; conversely, smaller capacitance capacitors charge and discharge faster, making them more suitable for high-frequency signal filtering or coupling. In engineering applications, capacitance is a nominal parameter explicitly marked at the factory, and the industry generally recognizes a certain percentage (e.g., 80%) of the nominal value as the failure threshold.

[0070] Step S140: Calculate the loss tangent of the capacitor under test based on the equivalent series resistance and capacitive reactance.

[0071] Specifically, the loss tangent of the capacitor under test is D=tan(δ)=ESR / Xc =(cos(θ) / sin(θ)), where θ is the phase angle, ESR is the equivalent series resistance, and δ is the loss angle, which is the complementary angle of θ.

[0072] Understandably, in an ideal capacitor, the current phase leads the voltage by 90°. However, in a real capacitor, due to parasitic parameters such as equivalent series resistance, the phase difference between the current and voltage is less than 90°. Therefore, the loss angle is the difference between 90° and the phase difference. Thus, the loss angle is a physical quantitative indicator of a real capacitor's deviation from ideal capacitance. The larger the loss angle, the further the capacitor deviates from its ideal characteristics, and the more severe the energy loss. From the formula for calculating the loss angle tangent, we know that the numerator, ESR, is the physical carrier of capacitor energy loss. When current flows through the ESR, electrical energy is converted into heat energy, which is the core source of capacitor energy loss. The denominator, capacitive reactance Xc, is the core function of the capacitor in storing / releasing charge. Capacitive reactance is the capacitive impedance of the capacitor to AC signals and is directly related to the capacitor's charging and discharging capability. The smaller the capacitive reactance, the stronger the capacitance, and the better the charging and discharging capability. Therefore, the loss angle tangent of the capacitor under test represents the degree of energy loss. Under the same capacitive function, the larger the loss angle tangent, the more severe the energy loss; conversely, the smaller the tangent, the closer the capacitor is to its ideal state, and the higher the energy utilization efficiency.

[0073] Step S150: Calculate the health of the capacitor under test based on the equivalent series resistance, capacitance, and loss tangent.

[0074] Understandably, calculating the health status by combining three indicators related to capacitor aging and usage time (equivalent series resistance, capacitance, and loss tangent) can provide a more accurate and comprehensive assessment of the capacitor's health.

[0075] Specifically, the health status of the capacitor under test can be calculated using the following formula:

[0076]

[0077] in, For equivalent series resistance, For capacity, This is the tangent of the loss angle. This is the equivalent series resistance measured when the capacitor under test is used for the first time. The capacitance value is the value measured when the capacitor under test is used for the first time. This is the loss tangent value measured when the capacitor under test is used for the first time. This is the weighting factor for the equivalent series resistance. This is the capacity weighting coefficient. The weighting coefficient is the tangent of the loss angle. The magnitude of each weighting coefficient is related to the capacitor type (electrolytic, ceramic, thin film).

[0078] Furthermore, , and Calibration can also be performed by training a model, and the trained model can also predict the health of the capacitor under test.

[0079] Specifically, current and voltage signals can be input into a pre-established capacitor health prediction model, which outputs the health status of the capacitor under test.

[0080] The process of establishing a capacitor health prediction model may include:

[0081] Obtain training sample data.

[0082] The training sample data may include the type, brand, usage time, and degradation data of each capacitor.

[0083] Specifically, capacitor types can include ceramic capacitors, electrolytic capacitors, and tantalum capacitors. Ceramic capacitors can be classified according to capacitance (0.1nF~100μF), voltage rating (6.3V~500V), and temperature coefficient (e.g., C0G, X7R, Y5V), with significant differences in dielectric loss characteristics among different subtypes. Electrolytic capacitors can be classified according to dielectric form and packaging type. For example, liquid electrolytic capacitors degrade faster due to the electrolyte drying out easily, while solid electrolytic capacitors have a longer lifespan; data needs to be collected separately for each. Tantalum capacitors can be classified according to anode material and electrolyte type to avoid the model's optimization of tantalum capacitor false negative rates failing due to subtype differences.

[0084] In terms of usage time, it can be divided into four stages. New stage (0 hours, not powered on): Collecting the capacitor's initial parameters at the factory ( , , This serves as the baseline data for 100% health. Short-term aging (100-1000 hours, light use): Simulates short-term operating conditions of consumer electronics and industrial control equipment, recording minor parameter changes. Mid-term aging (1000-10000 hours, normal service): Corresponds to long-term stable operating scenarios such as data center servers and factory machine tools, capturing linear parameter degradation. Long-term aging and critical failure (10000-100000+ hours): Simulates harsh operating conditions with high temperature and high ripple, recording parameter mutations and critical states before failure.

[0085] Furthermore, the regression model can be trained using training sample data to adjust the weighting coefficients of the equivalent series resistance, capacitance, and loss tangent used to calculate capacitor health, thereby obtaining a capacitor health prediction model.

[0086] Specifically, the regression model can be a linear regression model, a random forest model, or a neural network model. The trained capacitor health prediction model can be used to predict capacitor health and remaining life based on current and voltage signals.

[0087] Understandably, different types of capacitors have different specifications for equivalent series resistance, capacitance, and loss tangent. More stringent requirements necessitate a higher weighting. Therefore, model training allows the model to learn the weighting distribution of different types and brands of capacitors in the sample during training, thus yielding a more accurate result. , and .

[0088] The capacitor health detection method provided in this embodiment obtains the current and voltage signals of the capacitor under test by applying a sinusoidal test signal. The phase angle of the capacitor is calculated from the current and voltage signals. Based on the phase angle, the equivalent series resistance and capacitive reactance of the capacitor are calculated, and the capacitance is calculated based on the capacitive reactance. The loss tangent of the capacitor is calculated based on the equivalent series resistance and the capacitive reactance. The capacitor health is predicted based on the changes in the equivalent series resistance, capacitance, and loss tangent. Therefore, this method can actively measure the current and voltage signals of the capacitor during normal operation and comprehensively calculate its health based on the equivalent series resistance, capacitance, and loss tangent, thus providing a more accurate and comprehensive assessment of the capacitor's health and enabling early warning and troubleshooting of abnormal capacitors.

[0089] In some embodiments of this application, the capacitor health detection device mentioned in the above embodiments is further described. The acquisition circuit of the capacitor health detection device may include a sine wave generator, a current-to-voltage conversion circuit, an analog-to-digital converter, and a phase detection circuit.

[0090] Specifically, the sine wave generator can employ a Direct Digital Synthesis (DDS) chip or a precision programmable oscillator to produce a pure, frequency-tunable sine wave. The current-to-voltage conversion circuit can be a constant current source to ensure the stability of the current amplitude flowing through the capacitor, facilitating accurate measurement. The coordinated operation of the analog-to-digital converter (ADC) and phase detection circuit allows for simultaneous measurement of the voltage across the capacitor and the amplitude and phase difference of the current flowing through it, through synchronous sampling.

[0091] In some embodiments of this application, the capacitor health detection device mentioned in the above embodiments is further described. The capacitor health detection device can be designed in two ways.

[0092] The first approach, considering the higher spatial integration of capacitor health testing equipment to facilitate the inspection of capacitors distributed across various locations such as factory workshops, data centers, and wind power sites, can be designed with two probes. For example, the probes could be... Figure 2As shown, the tip of the probe is the detection area, the middle of the probe body is the core processing area, and the back / handle of the probe is the power interface area. Based on this, all circuits of the capacitance health detection device (including the acquisition circuit and functional circuit) can be integrated into the handle of the probe, making it convenient for maintenance personnel to carry.

[0093] The second type of capacitor health testing device can be designed with two probes and a main unit, such as... Figure 3 As shown, the main unit can house the processing circuitry of the capacitor health detection device, and is equipped with a PCB, battery, and FPC cable. The main unit provides interactive buttons, a display screen, and two probe ports. The two probes are connected to the two probe ports and to the main unit. The probe body integrates a data acquisition circuit to acquire the voltage and current signals of the capacitor under test and transmit them to the main unit, so that the main unit can evaluate and calculate the health status based on the voltage and current signals.

[0094] Furthermore, the probes can be connected using a four-wire Kelvin connection for testing, such as... Figure 4 As shown.

[0095] Understandably, in a four-wire Kelvin connection, one pair of wires provides the test current, while the other pair measures the actual voltage across the capacitor with high impedance, completely eliminating the influence of lead resistance and contact resistance on ESR measurement accuracy. The four-wire resistance measurement method separates the output current trace from the lead that reads the voltage across the resistor under test. Two of the four wires are used to provide a constant current, and the other two are used to measure the voltage across the resistor under test. With this design, the resistance of the test leads (Rwire) and the contact resistance in the current trace can be ignored, allowing direct measurement of the voltage drop across the resistor under test (Rsubject).

[0096] In some embodiments of this application, the capacitance health detection device mentioned in the above embodiments is further described, and the capacitance health detection device may include a display screen.

[0097] Specifically, the display screen can be used to show the test results of the capacitor under test, so that users can obtain the test information of the capacitor under test more conveniently and intuitively.

[0098] The test results can include the capacitance, capacitive reactance, equivalent series resistance, loss tangent, and health status of the capacitor under test. Users can customize one or more indicators to be displayed on the screen.

[0099] Furthermore, considering the ease of data transfer, the capacitor health testing equipment can also include a Bluetooth module. The Bluetooth module can send the test results of the capacitor under test to the terminal for data recording, trend analysis, and report generation.

[0100] The following describes the device for detecting capacitor health provided in the embodiments of this application. The device for detecting capacitor health described below and the method for detecting capacitor health described above can be referred to in correspondence.

[0101] See Figure 5 , Figure 5 This is a schematic diagram of a device for detecting capacitor health according to an embodiment of this application.

[0102] like Figure 5 As shown, the device may include a current and voltage test probe 11 and an MCU 12. The MCU 12 includes a phase angle and impedance calculation unit 121, an equivalent series resistance and capacitive reactance calculation unit 122, a capacity calculation unit 123, a loss tangent calculation unit 124, and a health calculation unit 125.

[0103] Specifically, the MCU12 can be selected from ARM Cortex-M series processors (such as the STM32G4 series) with built-in high-precision ADC and digital-to-analog converter (DAC). It has its own operational amplifier and ADC, making it very suitable for digital signal processing and vector computation.

[0104] The chip can be an integrated impedance analysis chip, such as ADI's AD5933. The AD5933 integrates a high sampling rate frequency generator. It can generate a specific frequency to excite an external resistor. The response signal obtained across the resistor is sampled by the ADC and subjected to a discrete Fourier transform by the on-chip Digital Signal Processor (DSP). The Fourier transform returns the real part R and the imaginary part I at the output frequency, thus making it easy to calculate the magnitude of the Fourier transform and the phase angle of the resistor at each scan frequency.

[0105] The current and voltage test probe 11 is used to obtain the current and voltage signals of the capacitor under test by applying a sinusoidal test signal to the capacitor under test.

[0106] The phase angle and impedance calculation unit 121 is used to calculate the phase angle and impedance of the capacitor under test using the current signal and the voltage signal.

[0107] The equivalent series resistance and capacitive reactance calculation unit 122 is used to calculate the equivalent series resistance and capacitive reactance of the capacitor under test based on the phase angle and the impedance.

[0108] The capacity calculation unit 123 is used to calculate the capacity of the capacitor under test based on the capacitive reactance;

[0109] The loss tangent calculation unit 124 is used to calculate the loss tangent of the capacitor under test based on the equivalent series resistance and the capacitive reactance.

[0110] The health calculation unit 125 is used to calculate the health of the capacitor under test based on the equivalent series resistance, the capacitance, and the loss tangent.

[0111] Optionally, the health calculation unit includes:

[0112] The health calculation subunit is used to calculate the health of the capacitor under test using the following formula:

[0113]

[0114] in, The equivalent series resistance is given. For the capacity, The loss angle tangent value is... The equivalent series resistance is measured during the initial use of the capacitor under test. The capacitance measured during the initial use of the capacitor under test. The value is the loss tangent measured during the initial use of the capacitor under test. This is the weighting factor for the equivalent series resistance. This is the capacity weighting coefficient. The weighting coefficient is the tangent of the loss angle. .

[0115] Optionally, the capacitor health testing device may also include:

[0116] The health prediction unit is used to input the current signal and the voltage signal into a pre-established capacitor health prediction model and output the health of the capacitor under test.

[0117] The process of establishing the capacitor health prediction model includes:

[0118] Acquire training sample data, which includes the type, brand, usage time, and degradation data of each type of capacitor;

[0119] The regression model is trained using the training sample data to adjust the equivalent series resistance weight coefficient, the capacity weight coefficient, and the loss tangent weight coefficient used to calculate the capacitor health in the regression model, thereby obtaining a capacitor health prediction model.

[0120] Optionally, the acquisition circuit of the capacitor health detection device includes a sine wave generator, a current-to-voltage conversion circuit, an analog-to-digital converter, and a phase detection circuit.

[0121] Optionally, the capacitance health detection device includes two probes and a host unit. The host unit is connected to the two probes, the acquisition circuit is integrated into the probes, and the host unit houses the processing circuit of the capacitance health detection device.

[0122] Optionally, the capacitance health testing device includes two probes, and all circuitry of the device is integrated into the handles of the probes.

[0123] Optionally, the probes are connected in a four-wire Kelvin configuration for detection.

[0124] Optionally, the capacitor health testing device includes a display screen for displaying the test results of the capacitor under test.

[0125] Optionally, the capacitance health detection device further includes a Bluetooth module, and the capacitance health detection device also includes:

[0126] The transmitting unit is used to transmit the index detection results of the capacitor under test to the terminal via the Bluetooth module.

[0127] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0128] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The various embodiments can be combined as needed, and the same or similar parts can be referred to each other.

[0129] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for detecting capacitor health, characterized in that, This method, applied to capacitor health testing equipment, includes: By applying a sinusoidal test signal to the capacitor under test, the current and voltage signals of the capacitor under test are obtained. The phase angle and impedance of the capacitor under test are calculated using the current signal and the voltage signal. Based on the phase angle and the impedance, the equivalent series resistance and capacitive reactance of the capacitor under test are calculated, and the capacitance of the capacitor under test is calculated based on the capacitive reactance. Calculate the loss tangent of the capacitor under test based on the equivalent series resistance and the capacitive reactance. The health status of the capacitor under test is calculated based on the equivalent series resistance, the capacitance, and the loss tangent.

2. The method according to claim 1, characterized in that, The health status of the capacitor under test is calculated based on the equivalent series resistance, the capacitance, and the loss tangent, including: The health status of the capacitor under test is calculated using the following formula: in, The equivalent series resistance is given. For the capacity, The loss angle tangent value is... The equivalent series resistance is measured during the initial use of the capacitor under test. The capacitance measured during the initial use of the capacitor under test. The value is the loss tangent measured during the initial use of the capacitor under test. This is the weighting factor for the equivalent series resistance. This is the capacity weighting coefficient. The weighting coefficient is the tangent of the loss angle. .

3. The method according to claim 2, characterized in that, Also includes: The current signal and the voltage signal are input into a pre-established capacitor health prediction model, and the health status of the capacitor under test is output. The process of establishing the capacitor health prediction model includes: Acquire training sample data, which includes the type, brand, usage time, and degradation data of each type of capacitor; The regression model is trained using the training sample data to adjust the equivalent series resistance weight coefficient, the capacity weight coefficient, and the loss tangent weight coefficient used to calculate the capacitor health in the regression model, thereby obtaining a capacitor health prediction model.

4. The method according to claim 1, characterized in that, The acquisition circuit of the capacitor health detection device includes a sine wave generator, a current-to-voltage conversion circuit, an analog-to-digital converter, and a phase detection circuit.

5. The method according to claim 4, characterized in that, The capacitance health detection device includes two probes and a main unit. The main unit is connected to the two probes. The acquisition circuit is integrated into the probes. The main unit houses the processing circuit of the capacitance health detection device.

6. The method according to claim 1, characterized in that, The capacitance health testing device includes two probes, and all the circuitry of the device is integrated into the handles of the probes.

7. The method according to claim 5 or 6, characterized in that, The probes are connected in a four-wire Kelvin configuration for detection.

8. The method according to claim 1, characterized in that, The capacitor health testing device includes a display screen, which is used to display the test results of the capacitor under test.

9. The method according to claim 8, characterized in that, The capacitance health detection device further includes a Bluetooth module, and the method further includes: The Bluetooth module sends the test results of the capacitor under test to the terminal.

10. A capacitor health testing device, characterized in that, It includes current and voltage test probes and an MCU. The MCU includes a phase angle and impedance calculation unit, an equivalent series resistance and capacitive reactance calculation unit, a capacity calculation unit, a loss tangent calculation unit, and a health status calculation unit; among which, The current and voltage test probes are used to obtain the current and voltage signals of the capacitor under test by applying a sinusoidal test signal to the capacitor under test. The phase angle and impedance calculation unit is used to calculate the phase angle and impedance of the capacitor under test using the current signal and the voltage signal. The equivalent series resistance and capacitive reactance calculation unit is used to calculate the equivalent series resistance and capacitive reactance of the capacitor under test based on the phase angle and the impedance. The capacity calculation unit is used to calculate the capacity of the capacitor under test based on the capacitive reactance; The loss tangent calculation unit is used to calculate the loss tangent of the capacitor under test based on the equivalent series resistance and the capacitive reactance. The health calculation unit is used to calculate the health of the capacitor under test based on the equivalent series resistance, the capacitance, and the loss tangent.

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