Partial discharge sensor performance detection system and method based on programmable discharge pulse
By using a programmable discharge pulse-based partial discharge sensor performance testing system, a programmable pulse generator and a performance testing unit are employed to achieve simultaneous time-domain and frequency-domain performance testing of partial discharge sensors. This solves the problems of cumbersome operation and high cost of existing methods and provides an efficient performance evaluation method.
Patent Information
- Application Number
- CN202511276441.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-08
- Publication Date
- 2025-12-12
AI Technical Summary
Existing methods for testing the performance of partial discharge current sensors require the cooperation of multiple devices, which are cumbersome and costly, and make it difficult to simultaneously achieve time-domain accuracy and frequency-domain response analysis.
A partial discharge sensor performance testing system based on programmable discharge pulses is adopted, including a discharge pulse generation device, a partial discharge sensor under test, and a performance testing unit. The system generates programmable pulses to simulate partial discharge signals through programmable control, and performs time-domain and frequency-domain processing to calculate correlation coefficients, transfer functions, rise time errors, and DTW distances, thereby achieving comprehensive detection.
It can simultaneously reflect the time-domain dynamic characteristics and frequency-domain response characteristics of the sensor without the need for additional spectrum analysis equipment, providing a more realistic test benchmark, reducing testing costs and simplifying the process.
Smart Images
Figure CN121114892A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of power equipment testing technology, and in particular to a partial discharge sensor performance testing system and method based on programmable discharge pulses. Background Technology
[0002] Partial discharge current sensors are key components in the insulation condition monitoring of power equipment, and their performance directly affects the measurement accuracy and diagnostic reliability of partial discharge signals. Currently, common performance testing methods for partial discharge current sensors require the combined use of multiple devices, such as network analyzers, swept frequency signal generators, and high-speed signal generators, to complete the testing of various performance indicators, including time-domain accuracy and frequency-domain response analysis.
[0003] Common performance testing methods require numerous testing devices, are cumbersome to operate, and are costly, making it difficult to simultaneously achieve time-domain accuracy and frequency-domain response analysis. Therefore, there is an urgent need for a performance testing method for partial discharge sensors that can simultaneously test time-domain and frequency-domain performance, simplifying the performance testing process and reducing costs. Summary of the Invention
[0004] Based on the above analysis, the present invention aims to disclose a partial discharge sensor performance testing system and method based on programmable discharge pulses, thereby solving the performance testing problem of partial discharge sensors.
[0005] This invention discloses a partial discharge sensor performance testing system based on programmable discharge pulses, comprising: a discharge pulse generating device, a partial discharge sensor under test, and a performance testing unit;
[0006] The performance testing unit is connected to the discharge pulse generating device and the partial discharge sensor under test, respectively.
[0007] The discharge pulse generating device uses a programmable pulse with controlled parameters, including pulse amplitude, phase, and frequency, to simulate the partial discharge signal of the transformer under different operating conditions.
[0008] The partial discharge sensor under test receives partial discharge signals, performs discharge pulse measurement, and outputs a measurement signal.
[0009] The performance testing unit performs time-domain and frequency-domain processing on the partial discharge signal and the measurement signal, calculates the correlation coefficient, transfer function, rise time error, and DTW distance of the partial discharge signal and the detection signal, and performs comprehensive testing of the partial discharge sensor, including measurement accuracy, frequency response characteristics, transient response capability, and signal fidelity.
[0010] Furthermore, the performance testing unit includes a first measurement module, a second measurement module, a third measurement module, and a fourth measurement module; wherein,
[0011] The first measurement module is used to calculate and output the correlation coefficient between the partial discharge signal and the measurement signal in the time domain to measure the accuracy of the partial discharge sensor under test.
[0012] The second measurement module is used to solve the transfer function of the partial discharge sensor under test in the frequency domain. The output transfer function curve characterizes the frequency response characteristics of the partial discharge sensor under test, and the average gain of the output transfer function characterizes the gain impedance of the partial discharge sensor under test.
[0013] The third measurement module is used to solve the pulse rise time of the partial discharge signal and the measurement signal in the time domain, and to calculate and output the pulse rise time error of the partial discharge signal and the corresponding measurement signal to characterize the transient response capability of the partial discharge sensor under test.
[0014] The fourth measurement module is used to detect the pulse waveform fidelity of the partial discharge signal and the measurement signal in the time domain to obtain the DTW distance between the two signals, which characterizes the signal fidelity of the partial discharge sensor under test.
[0015] Furthermore, the discharge pulse generating device includes:
[0016] It includes a DC voltage control module, a pulse signal generation module, and a phase control module;
[0017] The DC voltage control module is used to generate a DC voltage with controlled amplitude under program control and output it to the pulse signal generation module to control the amplitude of the pulse output by the pulse signal generation module.
[0018] The phase control module is used to generate delayed trigger pulses under program control and output them to the pulse signal generation module, thereby controlling the phase of the output pulses from the pulse signal generation module.
[0019] The pulse signal generation module is used to generate a phase-controlled, nanosecond-level leading-edge programmable pulse under the triggering of a time-delayed trigger pulse; and the amplitude of the programmable pulse is controlled by the DC voltage output by the DC voltage control module.
[0020] Furthermore, the pulse signal generation module includes a first-stage avalanche transistor group, a first-stage base differentiating circuit, a first-stage discharge buffer circuit, a second-stage base differentiating circuit, a second-stage avalanche transistor group, a main discharge capacitor, and a second-stage discharge buffer circuit; wherein,
[0021] The first-stage avalanche transistor group consists of M avalanche transistor groups connected in parallel; the collector of each avalanche transistor in the first stage is connected to resistor R3, and DC voltage UCC is connected through resistor R3. The emitters of all transistors are grounded, and the bases are connected together and connected to the output terminal of the first-stage base differentiating circuit.
[0022] The first-stage base differentiating circuit includes resistors R1 and R2 and capacitor C1; resistor R1 is connected between one end of capacitor C1 and ground, and resistor R2 is connected between the other end of capacitor C1 and ground; the externally input trigger pulse is input from the end where resistor R1 and capacitor C1 are connected; the differentiated signal is output from the end where resistor R2 and capacitor C1 are connected to the base of the first-stage avalanche transistor group.
[0023] The first-stage discharge buffer circuit includes a resistor R10 and a fast recovery diode D2; the resistor R10 and the fast recovery diode D2 are connected in series between the base of the first-stage avalanche transistor and ground;
[0024] The second-stage base differentiator circuit includes capacitor C2 and resistor R8, which are connected in series. The connection point of capacitor C2 and resistor R8 is the output terminal of the second-stage base differentiator circuit. The other end of capacitor C2 is connected to the collector of each avalanche transistor in the first stage, and the other end of resistor R8 is grounded.
[0025] The second-stage avalanche transistor group consists of N avalanche transistors connected in parallel; the collector of each avalanche transistor in the second stage is connected to resistor R4, and DC voltage UCC is connected through resistor R4; the base of each avalanche transistor in the second stage is connected to the output terminal of the second-stage base differentiating circuit through its respective base resistor; the emitter of each avalanche transistor in the second stage is connected to the output terminal of the second-stage base differentiating circuit.
[0026] One end of the main discharge capacitor is connected to the collector of each avalanche transistor in the second stage, and the other end serves as the output terminal of the pulse signal generation module.
[0027] The second-stage discharge buffer circuit includes resistor R9 and fast recovery diode D1; resistor R9 and fast recovery diode D1 are connected in series between the output terminal of the first-stage pulse signal generation module and ground.
[0028] Furthermore, the DC voltage control module includes a digital potentiometer and an operational amplifier;
[0029] The SCL and SDA terminals of the digital potentiometer are configured by a programmable input, and the output terminal is connected to an operational amplifier. The operational amplifier is connected to a proportional amplifier circuit to proportionally amplify the voltage output by the digital potentiometer and then output it to the pulse signal generation module to control the amplitude of the pulse output by the pulse signal generation module.
[0030] The value of the programmable configuration word input at the SDA terminal corresponds to the amplitude of the pulse output by the pulse signal generation module, and the timing of the programmable control command at the SCL terminal corresponds to the timing of the pulse output by the pulse signal generation module.
[0031] Furthermore, the phase control module includes a trigger pulse generation circuit and a controllable timing circuit;
[0032] The trigger pulse generation circuit includes a sinusoidal signal source and a zero-crossing detection circuit;
[0033] The sinusoidal signal source generates a sinusoidal synchronization signal with the same frequency as the required trigger pulse and outputs it to the zero-crossing detection circuit; the zero-crossing detection circuit determines the phase zero point of the sinusoidal synchronization signal and outputs the trigger pulse sequence to the controllable timing circuit.
[0034] The controllable timing circuit adjusts the pulse interval of the trigger pulse sequence according to the set timing length to form a delayed trigger pulse sequence output.
[0035] Furthermore, it also includes a waveform modulation module, which is used to programmatically adjust the parameters of the programmable pulse output by the pulse signal generation module, including pulse width, rise time, and oscillation frequency, to simulate the partial discharge signal of various signal parameter ranges actually encountered by the partial discharge sensor under test.
[0036] Furthermore, the waveform modulation module includes a pulse width adjustment submodule, a rise time adjustment submodule, and an oscillation frequency adjustment submodule; wherein,
[0037] The pulse width modulation (PWM) submodule includes multiple parallel RC damping circuits. Each RC damping circuit includes a resistor and capacitor connected in series between the output of the pulse signal generation module and ground, with the connection point of the resistor and capacitor serving as the output of the RC damping circuit. The outputs of multiple RC damping circuits are connected together to form the output of the PWM submodule. Each RC damping circuit also has a switch connected in series to control whether that circuit participates in pulse width modulation. By controlling the closing of different numbers of switches, the pulse width can be adjusted.
[0038] The rise time adjustment submodule includes multiple resistors and capacitors arranged in parallel. These parallel resistors and capacitors are connected in series with their respective control switches and then connected between the output terminal of the pulse width adjustment submodule and ground, forming an RC differential circuit whose pulse rise time is controlled by the switches. By controlling the number of switches closed, the number of resistors and capacitors connected to the circuit to change the differential parameters is selected for adjusting the pulse rise time.
[0039] The oscillation frequency adjustment submodule includes multiple parallel LC resonant circuits. The input signal in each LC resonant circuit is output after passing through a series inductor and capacitor. The output terminals of the multiple LC resonant circuits are connected together as the output terminal of the waveform modulation module. Each LC resonant circuit also has a switch connected in series to control whether the LC resonant circuit participates in the oscillation frequency adjustment. By controlling the closing of different numbers of switches, the pulse oscillation frequency can be adjusted.
[0040] This invention also discloses a performance testing method for a partial discharge sensor performance testing system based on programmable discharge pulses as described above, comprising:
[0041] Step S1: Adjust the parameters of the discharge pulse generating device to ensure that the discharge pulse generating device can output a partial discharge signal with a set amplitude, phase and frequency;
[0042] Step S2: Measure the partial discharge signal using the partial discharge sensor under test;
[0043] Step S3: The performance testing unit receives the partial discharge signal and the measurement signal, performs time-domain and frequency-domain processing, calculates the correlation coefficient, transfer function, rise time error and DTW distance of the partial discharge signal and the detection signal, and performs a comprehensive test of the partial discharge sensor, including measurement accuracy, frequency response characteristics, transient response capability and signal fidelity.
[0044] Further, step S3 includes:
[0045] Step 301: Perform frequency domain transformation on the partial discharge signal and the measurement signal respectively to obtain the frequency domain signals;
[0046] Step 302: Calculate and output the correlation coefficient between the partial discharge signal and the measurement signal in the time domain to measure the accuracy of the partial discharge sensor under test;
[0047] Step 303: Solve for the transfer function of the partial discharge sensor under test in the frequency domain. The output transfer function curve characterizes the frequency response characteristics of the partial discharge sensor under test, and the average gain of the output transfer function characterizes the gain impedance of the partial discharge sensor under test.
[0048] Step 304: Solve for the pulse rise time of the partial discharge signal and the measurement signal in the time domain, and calculate and output the pulse rise time error of the partial discharge signal and the corresponding measurement signal to characterize the transient response capability of the partial discharge sensor under test.
[0049] Step 305: Detect the pulse waveform fidelity of the partial discharge signal and the measurement signal in the time domain to obtain the DTW distance between the two signals, which characterizes the signal fidelity of the partial discharge sensor under test.
[0050] One of the beneficial effects achievable by this invention is:
[0051] The present invention discloses a partial discharge sensor performance testing system and method based on programmable discharge pulses. The system uses a programmable discharge pulse generator to generate partial discharge pulses, calculates the time-domain and frequency-domain characteristics of the sensor's output signal and the partial discharge pulses of the transmitting device, thereby obtaining the sensor's measurement accuracy, frequency domain response characteristics and transient response capability, and completing the performance testing of the partial discharge current sensor. It does not require additional spectrum analysis equipment and simultaneously reflects the sensor's time-domain dynamic characteristics and frequency domain response characteristics.
[0052] The programmable discharge pulse generator has strong parameter adjustability: by independently or in combination adjusting parameters such as the amplitude, width, rise time, and oscillation frequency of the pulse signal, it can simulate various partial discharge signal characteristics, cover the complex scenarios of various partial discharge sensors in actual detection, and generate simulated signals that highly match the actual partial discharge characteristics inside power equipment, providing a more realistic test benchmark for the performance testing of partial discharge sensors. Attached Figure Description
[0053] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.
[0054] Figure 1 This is a schematic diagram showing the components and connections of the partial discharge sensor performance testing system in an embodiment of the present invention;
[0055] Figure 2 This is a schematic diagram showing the connection of the discharge pulse generating device in an embodiment of the present invention;
[0056] Figure 3 This is a schematic diagram of the pulse signal generation module circuit in an embodiment of the present invention;
[0057] Figure 4 This is a circuit schematic diagram of the DC voltage control module in an embodiment of the present invention;
[0058] Figure 5 This is a block diagram of the phase control module in an embodiment of the present invention;
[0059] Figure 6 This is a circuit schematic diagram of the waveform modulation module in an embodiment of the present invention;
[0060] Figure 7 This is a flowchart of the performance testing method of the partial discharge sensor performance testing system based on programmable discharge pulse in an embodiment of the present invention. Detailed Implementation
[0061] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and, together with the embodiments of the present invention, serve to illustrate the principles of the present invention.
[0062] Example 1
[0063] One embodiment of the present invention discloses a partial discharge sensor performance detection system based on programmable discharge pulses, such as... Figure 1 As shown, it includes: a discharge pulse generating device, a partial discharge sensor under test, and a performance testing unit;
[0064] The performance testing unit is connected to the discharge pulse generating device and the partial discharge sensor under test, respectively.
[0065] The discharge pulse generating device uses a programmable pulse with controlled parameters, including pulse amplitude, phase, and frequency, to simulate the partial discharge signal of the transformer under different operating conditions.
[0066] The partial discharge sensor under test is a discharge current sensor, which receives partial discharge signals, performs discharge pulse measurement, and outputs a measurement signal;
[0067] The performance testing unit performs time-domain and frequency-domain processing on the partial discharge signal and the measurement signal, calculates the correlation coefficient, transfer function, rise time error, and DTW distance of the partial discharge signal and the detection signal, and performs comprehensive testing of the partial discharge sensor, including measurement accuracy, frequency response characteristics, transient response capability, and signal fidelity.
[0068] Specifically, such as Figure 2 As shown, the discharge pulse generating device includes:
[0069] It includes a DC voltage control module, a pulse signal generation module, and a phase control module;
[0070] The DC voltage control module is used to generate a DC voltage with controlled amplitude under program control and output it to the pulse signal generation module to control the amplitude of the pulse output by the pulse signal generation module.
[0071] The phase control module is used to generate delayed trigger pulses under program control and output them to the pulse signal generation module, thereby controlling the phase of the output pulses from the pulse signal generation module.
[0072] The pulse signal generation module is used to generate a phase-controlled, nanosecond-level leading-edge programmable pulse under the triggering of a time-delayed trigger pulse; and the amplitude of the programmable pulse is controlled by the DC voltage output by the DC voltage control module.
[0073] In a preferred embodiment, the discharge pulse generating device further includes a waveform modulation module, which is used to programmatically adjust the parameters of the programmable pulse output by the pulse signal generating module, including pulse width, rise time, and oscillation frequency, to simulate a partial discharge signal that covers the range of various signal parameters encountered by the partial discharge sensor in actual detection.
[0074] In a preferred embodiment, the discharge pulse generating device further includes a power amplification module, which amplifies the power of each pulse in the waveform-adjusted pulse sequence to ensure that the output pulse signal has sufficient energy to effectively excite the partial discharge sensor, so that the signal strength received during performance testing is close to the actual working signal strength.
[0075] In an optional embodiment, for a partial discharge sensor capable of receiving ultra-high frequency signals, the discharge pulse generating device further includes a signal transmitting module connected to the power amplification module.
[0076] A broadband RF power amplifier (operating frequency band 300MHz-3GHz, gain ≥30dB) is preferred to ensure that the output signal power can reach more than 10W.
[0077] The signal transmission module is connected to the power amplifier module and is equipped with a 50Ω impedance-matched UHF transmitting antenna (operating frequency 300MHz-3000MHz) connected via a coaxial cable. It is used to output the amplified pulse signal to the UHF transmitting antenna. Its output port is matched with the input impedance of the UHF sensor (usually 50Ω) to ensure efficient signal transmission and coupling, and reduce signal loss and distortion during transmission.
[0078] Specifically, the pulse signal generation module in the discharge pulse generation device is composed of a multi-stage series avalanche transistor circuit. It uses a square wave trigger signal to control the avalanche breakdown of the transistor to generate a nanosecond-level leading pulse signal, and controls the amplitude of the nanosecond-level leading pulse signal by controlling the DC charging voltage.
[0079] More specifically, the pulse signal generation module includes a first-stage avalanche transistor group, a first-stage base differentiating circuit, a first-stage discharge buffer circuit, a second-stage base differentiating circuit, a second-stage avalanche transistor group, a main discharge capacitor, and a second-stage discharge buffer circuit; among which,
[0080] The first-stage avalanche transistor group consists of M avalanche transistor groups connected in parallel; the collector of each avalanche transistor in the first stage is connected to resistor R3, and DC voltage UCC is connected through resistor R3. The emitters of all transistors are grounded, and the bases are connected together and connected to the output terminal of the first-stage base differentiating circuit.
[0081] The first-stage base differentiating circuit includes resistors R1 and R2 and capacitor C1; resistor R1 is connected between one end of capacitor C1 and ground, and resistor R2 is connected between the other end of capacitor C1 and ground; the externally input trigger pulse is input from the end where resistor R1 and capacitor C1 are connected; the differentiated signal is output from the end where resistor R2 and capacitor C1 are connected to the base of the first-stage avalanche transistor group.
[0082] The first-stage discharge buffer circuit includes a resistor R10 and a fast recovery diode D2; the resistor R10 and the fast recovery diode D2 are connected in series between the base of the first-stage avalanche transistor and ground;
[0083] The second-stage base differentiator circuit includes capacitor C2 and resistor R8, which are connected in series. The connection point of capacitor C2 and resistor R8 is the output terminal of the second-stage base differentiator circuit. The other end of capacitor C2 is connected to the collector of each avalanche transistor in the first stage, and the other end of resistor R8 is grounded.
[0084] The second-stage avalanche transistor group consists of N avalanche transistors connected in parallel; the collector of each avalanche transistor in the second stage is connected to resistor R4, and DC voltage UCC is connected through resistor R4; the base of each avalanche transistor in the second stage is connected to the output terminal of the second-stage base differentiating circuit through its respective base resistor; the emitter of each avalanche transistor in the second stage is connected to the output terminal of the second-stage base differentiating circuit.
[0085] One end of the main discharge capacitor is connected to the collector of each avalanche transistor in the second stage, and the other end serves as the output terminal of the pulse signal generation module.
[0086] The second-stage discharge buffer circuit includes resistor R9 and fast recovery diode D1; resistor R9 and fast recovery diode D1 are connected in series between the output terminal of the first-stage pulse signal generation module and ground.
[0087] The number of transistors in the first-stage avalanche transistor group and the second-stage avalanche transistor group is determined according to the pulse current requirements; for example... Figure 3 As shown, a specific circuit example is given where both the first-stage avalanche transistor group and the second-stage avalanche transistor group consist of three transistors.
[0088] In the example, after differentiation, the trigger pulse is first connected to the base of transistors Q1-Q3 in the first-stage avalanche transistor group that are in a critical avalanche state; at least one of Q1-Q3 undergoes avalanche; the output signal of the transistor in the first-stage avalanche transistor group after avalanche is differentiated by the second-stage base differentiating circuit and output as a pulse signal, which is sent to the emitter of transistors Q4-Q6 in the second-stage avalanche transistor group, increasing the voltage drop between the collector and emitter of Q4-Q6, causing at least one of Q4-Q6 to undergo avalanche; the voltage drop of the newly turned-on transistor causes the voltage drop on the other two unturned transistors to be redistributed, ultimately causing each avalanche transistor to undergo avalanche. In the first-stage discharge buffer circuit and the second-stage discharge buffer circuit, the fast recovery diode is used to reduce the backlash during discharge and to play a role in temperature compensation.
[0089] The DC voltage UCC charges capacitor C2 through resistors R3 and R5. When a trigger pulse is applied, causing the transistor to avalanche, the first and second avalanche transistors conduct, causing capacitor C2 to discharge through the conducting second avalanche transistor and the resistor connected to its base. The output step signal is differentiated by capacitor C3 to obtain the output pulse. By changing C2 and UCC, the peak-to-peak value of the output pulse can be changed. Increasing C2 not only increases the peak-to-peak value but also increases the output pulse width.
[0090] Specifically, the DC voltage control module in the discharge pulse generating device includes a digital potentiometer and an operational amplifier;
[0091] The SCL and SDA terminals of the digital potentiometer are configured by a programmable input, and the output terminal is connected to an operational amplifier. The operational amplifier is connected to a proportional amplifier circuit to proportionally amplify the voltage output by the digital potentiometer and then output it to the pulse signal generation module to control the amplitude of the pulse output by the pulse signal generation module.
[0092] The value of the programmable configuration word input at the SDA terminal corresponds to the amplitude of the pulse output by the pulse signal generation module, and the timing of the programmable control command at the SCL terminal corresponds to the timing of the pulse output by the pulse signal generation module.
[0093] More specifically, the circuit connection of the DC voltage control module is as follows: Figure 4 As shown, the VDD and H pins of the digital potentiometer are connected to the power supply VCC, the SCL terminal is connected to the programmable control command, the SDA terminal is connected to the programmable configuration word, and the W pin outputs the voltage division value of the power supply VCC to the non-inverting input of the operational amplifier; the voltage division ratio is set by the programmable configuration word; the inverting input of the operational amplifier is grounded through resistor R1, and the output is fed back to the inverting input through resistor R2; the voltage is amplified by the ratio of R1 and R2 to obtain a controllable DC voltage.
[0094] Specifically, such as Figure 5 As shown, the phase control module in the discharge pulse generating device includes a trigger pulse generating circuit and a controllable timing circuit; wherein,
[0095] The trigger pulse generation circuit includes a sinusoidal signal source and a zero-crossing detection circuit;
[0096] The sinusoidal signal source generates a sinusoidal synchronization signal with the same frequency as the required trigger pulse and outputs it to the zero-crossing detection circuit; the zero-crossing detection circuit determines the phase zero point of the sinusoidal synchronization signal and outputs the trigger pulse sequence to the controllable timing circuit.
[0097] The controllable timing circuit adjusts the pulse interval of the trigger pulse sequence according to the set timing length to form a delayed trigger pulse sequence output.
[0098] More specifically, the controllable timing circuit is controlled through methods including the timing program inside the microcontroller. When the controllable timing circuit is controlled using the timing program inside the microcontroller, the TTL signal of the microcontroller pin is used as the control signal. When the timing length of the timing program is reached, the control trigger pulse is output.
[0099] Specifically, the waveform modulation module in the discharge pulse generating device includes a pulse width adjustment submodule, a rise time adjustment submodule, and an oscillation frequency adjustment submodule; among which,
[0100] The pulse width modulation (PWM) submodule includes multiple parallel RC damping circuits. Each RC damping circuit includes a resistor and capacitor connected in series between the output of the pulse signal generation module and ground, with the connection point of the resistor and capacitor serving as the output of the RC damping circuit. The outputs of multiple RC damping circuits are connected together to form the output of the PWM submodule. Each RC damping circuit also has a switch connected in series to control whether that circuit participates in pulse width modulation. By controlling the closing of different numbers of switches, the pulse width can be adjusted.
[0101] The rise time adjustment submodule includes multiple resistors and capacitors arranged in parallel. These parallel resistors and capacitors are connected in series with their respective control switches and then connected between the output terminal of the pulse width adjustment submodule and ground, forming an RC differential circuit whose pulse rise time is controlled by the switches. By controlling the number of switches closed, the number of resistors and capacitors connected to the circuit to change the differential parameters is selected for adjusting the pulse rise time.
[0102] The oscillation frequency adjustment submodule includes multiple parallel LC resonant circuits. The input signal in each LC resonant circuit is output after passing through a series inductor and capacitor. The output terminals of the multiple LC resonant circuits are connected together as the output terminal of the waveform modulation module. Each LC resonant circuit also has a switch connected in series to control whether the LC resonant circuit participates in the oscillation frequency adjustment. By controlling the closing of different numbers of switches, the pulse oscillation frequency can be adjusted.
[0103] For specific circuit connections of the waveform modulation module, please refer to [link / reference]. Figure 6 .
[0104] Preferably, the multiplexer in the waveform modulation module is a multi-tap switch composed of a relay array or a switching transistor array;
[0105] The control terminal of the switch is connected to the corresponding control signal after decoding by the decoder. The input of the decoder is the encoded signal set by the programmable control equipment according to the pulse width, rise time and oscillation frequency parameters. The decoder decodes the signal into the corresponding control signal and outputs it to the corresponding switch in the pulse width adjustment submodule, rise time adjustment submodule and oscillation frequency adjustment submodule to control the closing or opening of the switch and realize the adjustment of the pulse width, rise time and oscillation frequency of the pulse signal.
[0106] Specifically, the performance testing unit includes a first measurement module, a second measurement module, a third measurement module, and a fourth measurement module; among which,
[0107] The first measurement module is used to calculate and output the correlation coefficient between the partial discharge signal and the measurement signal in the time domain to measure the accuracy of the partial discharge sensor under test.
[0108] Correlation coefficient Where Cov(U1,U2) is the covariance of the time-domain signals U1(t) and U2(t). These are the standard deviations of the time-domain signals U1(t) and U2(t), respectively; U1(t) is the partial discharge pulse waveform of the discharge pulse generating device; and U2(t) is the output signal waveform of the partial discharge sensor.
[0109] The second measurement module is used to solve the transfer function of the partial discharge sensor under test in the frequency domain. The output transfer function curve characterizes the frequency response characteristics of the partial discharge sensor under test, and the average gain of the output transfer function characterizes the gain impedance of the partial discharge sensor under test.
[0110] transfer function Where U1(w) is the frequency domain signal of the partial discharge pulse waveform U1(t), and U2(w) is the frequency domain signal of the partial discharge sensor output signal waveform U2(t);
[0111] Average gain Where G(w) i ) represents the signal amplitude corresponding to the i-th frequency point in the frequency domain signal; n represents the number of frequency points in the frequency domain signal.
[0112] The third measurement module is used to solve the pulse rise time of the partial discharge signal and the measurement signal in the time domain, and to calculate and output the pulse rise time error of the partial discharge signal and the corresponding measurement signal to characterize the transient response capability of the partial discharge sensor under test.
[0113] In the third measurement module, the rise time τ1 of the partial discharge pulse and the rise time τ2 of the corresponding partial discharge sensor output signal are calculated. The error A between the sensor rise time and the rise time of the partial discharge pulse is calculated. When the error A is within the required error range p, the transient response capability of the sensor is considered to meet the requirements.
[0114] The rise time τ refers to the time it takes for the amplitude of the rising edge to rise from 10% to 90%.
[0115] rise time error
[0116] The fourth measurement module is used to detect the pulse waveform fidelity of the partial discharge signal and the measurement signal in the time domain to obtain the DTW distance between the two signals, which characterizes the signal fidelity of the partial discharge sensor under test; the DTW distance is the sum of the cumulative distances between the two signals.
[0117] In the fourth measurement module, the dynamic time warping algorithm is used to detect the signal fidelity of the partial discharge pulse waveform U1(t) and the partial discharge sensor output signal waveform U2(t), and the DTW distance between the two signals is used as the signal fidelity of the sensor.
[0118] In the dynamic time warping algorithm, the partial discharge pulse waveform U1(t) sequence is used as the reference sequence R with length n, and the partial discharge current sensor output signal waveform U2(t) sequence is used as the query sequence Q with length m. An n×m cumulative distance matrix D is defined, where the element D[i][j] represents the cumulative distance between the first i points of the query sequence Q and the first j points of the reference sequence R. The optimal path is a path from D[1][1] to D[n][m] that minimizes the sum of the cumulative distances on the path. This path can be obtained by dynamic programming. The sum of the cumulative distances on the optimal path is the DTW distance between the two sequences. The similarity of the waveforms is measured by the magnitude of the cumulative distance. The smaller the cumulative distance, the more similar the two waveforms are, and the higher the signal fidelity of the sensor.
[0119] Based on the correlation coefficient S and gain impedance output by the performance testing unit The transfer function G(w), rise time error A, and DTW distance measure the performance of a partial discharge sensor.
[0120] In summary, the partial discharge sensor performance testing system based on programmable discharge pulse disclosed in this embodiment uses a programmable discharge pulse generator to generate partial discharge pulses, calculates the time-domain and frequency-domain characteristics of the sensor's output signal and the partial discharge pulse of the transmitting device, thereby obtaining the sensor's measurement accuracy, frequency-domain response characteristics, and transient response capability, and completing the performance testing of the partial discharge current sensor. It does not require additional spectrum analysis equipment and simultaneously reflects the sensor's time-domain dynamic characteristics and frequency-domain response characteristics.
[0121] The programmable discharge pulse generator has strong parameter adjustability: by independently or in combination adjusting parameters such as the amplitude, width, rise time, and oscillation frequency of the pulse signal, it can simulate various partial discharge signal characteristics, cover the complex scenarios of various partial discharge sensors in actual detection, and generate simulated signals that highly match the actual partial discharge characteristics inside power equipment, providing a more realistic test benchmark for the performance testing of partial discharge sensors.
[0122] Example 2
[0123] One embodiment of the present invention discloses a performance testing method using the partial discharge sensor performance testing system based on programmable discharge pulses described in Embodiment 1, such as... Figure 7 As shown, it includes:
[0124] Step S1: Adjust the parameters of the discharge pulse generating device to ensure that the discharge pulse generating device can output a partial discharge signal with a set amplitude, phase and frequency;
[0125] Step S2: Measure the partial discharge signal using the partial discharge sensor under test;
[0126] Step S3: The performance testing unit receives the partial discharge signal and the measurement signal, performs time-domain and frequency-domain processing, calculates the correlation coefficient, transfer function, rise time error and DTW distance of the partial discharge signal and the detection signal, and performs a comprehensive test of the partial discharge sensor, including measurement accuracy, frequency response characteristics, transient response capability and signal fidelity.
[0127] Specifically, step S3 includes:
[0128] Step S301: Perform frequency domain transformation on the partial discharge signal and the measurement signal respectively to obtain frequency domain signals;
[0129] Step S302: Calculate and output the correlation coefficient between the partial discharge signal and the measurement signal in the time domain to measure the accuracy of the partial discharge sensor under test;
[0130] Step S303: Solve the transfer function of the partial discharge sensor under test in the frequency domain. The output transfer function curve characterizes the frequency response characteristics of the partial discharge sensor under test, and the average gain of the output transfer function characterizes the gain impedance of the partial discharge sensor under test.
[0131] Step S304: Solve for the pulse rise time of the partial discharge signal and the measurement signal in the time domain, and calculate and output the pulse rise time error of the partial discharge signal and the corresponding measurement signal to characterize the transient response capability of the partial discharge sensor under test.
[0132] Step S305: Detect the pulse waveform fidelity of the partial discharge signal and the measurement signal in the time domain to obtain the DTW distance between the two signals, which characterizes the signal fidelity of the partial discharge sensor under test.
[0133] More technical details in this embodiment are the same as those disclosed in Embodiment 1, and achieve the same technical effect. Please refer to them for details, and they will not be repeated here.
[0134] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.
Claims
1. A partial discharge sensor performance testing system based on programmable discharge pulses, characterized in that, include: Discharge pulse generating device, partial discharge sensor under test, and performance testing unit; The performance testing unit is connected to the discharge pulse generating device and the partial discharge sensor under test, respectively. The discharge pulse generating device uses a programmable pulse with controlled parameters, including pulse amplitude, phase, and frequency, to simulate the partial discharge signal of the transformer under different operating conditions. The partial discharge sensor under test receives partial discharge signals, performs discharge pulse measurement, and outputs a measurement signal. The performance testing unit performs time-domain and frequency-domain processing on the partial discharge signal and the measurement signal, calculates the correlation coefficient, transfer function, rise time error, and DTW distance of the partial discharge signal and the detection signal, and performs comprehensive testing of the partial discharge sensor, including measurement accuracy, frequency response characteristics, transient response capability, and signal fidelity.
2. The partial discharge sensor performance testing system based on programmable discharge pulses according to claim 1, characterized in that, The performance testing unit includes a first measurement module, a second measurement module, a third measurement module, and a fourth measurement module; among which, The first measurement module is used to calculate and output the correlation coefficient between the partial discharge signal and the measurement signal in the time domain to measure the accuracy of the partial discharge sensor under test. The second measurement module is used to solve the transfer function of the partial discharge sensor under test in the frequency domain. The output transfer function curve characterizes the frequency response characteristics of the partial discharge sensor under test, and the average gain of the output transfer function characterizes the gain impedance of the partial discharge sensor under test. The third measurement module is used to solve the pulse rise time of the partial discharge signal and the measurement signal in the time domain, and to calculate and output the pulse rise time error of the partial discharge signal and the corresponding measurement signal to characterize the transient response capability of the partial discharge sensor under test. The fourth measurement module is used to detect the pulse waveform fidelity of the partial discharge signal and the measurement signal in the time domain to obtain the DTW distance between the two signals, which characterizes the signal fidelity of the partial discharge sensor under test.
3. The partial discharge sensor performance testing system based on programmable discharge pulses according to claim 1, characterized in that, The discharge pulse generating device includes: It includes a DC voltage control module, a pulse signal generation module, and a phase control module; The DC voltage control module is used to generate a DC voltage with controlled amplitude under program control and output it to the pulse signal generation module to control the amplitude of the pulse output by the pulse signal generation module. The phase control module is used to generate delayed trigger pulses under program control and output them to the pulse signal generation module, thereby controlling the phase of the output pulses from the pulse signal generation module. The pulse signal generation module is used to generate a phase-controlled, nanosecond-level leading-edge programmable pulse under the triggering of a time-delayed trigger pulse; and the amplitude of the programmable pulse is controlled by the DC voltage output by the DC voltage control module.
4. The partial discharge sensor performance testing system based on programmable discharge pulses according to claim 3, characterized in that, The pulse signal generation module includes a first-stage avalanche transistor group, a first-stage base differentiating circuit, a first-stage discharge buffer circuit, a second-stage base differentiating circuit, a second-stage avalanche transistor group, a main discharge capacitor, and a second-stage discharge buffer circuit; among which, The first-stage avalanche transistor group consists of M avalanche transistor groups connected in parallel; the collector of each avalanche transistor in the first stage is connected to resistor R3, and DC voltage UCC is connected through resistor R3. The emitters of all transistors are grounded, and the bases are connected together and connected to the output terminal of the first-stage base differentiating circuit. The first-stage base differentiating circuit includes resistors R1 and R2 and capacitor C1; resistor R1 is connected between one end of capacitor C1 and ground, and resistor R2 is connected between the other end of capacitor C1 and ground; the externally input trigger pulse is input from the end where resistor R1 and capacitor C1 are connected; the differentiated signal is output from the end where resistor R2 and capacitor C1 are connected to the base of the first-stage avalanche transistor group. The first-stage discharge buffer circuit includes resistor R10 and fast recovery diode D2; resistor R10 and fast recovery diode D2 are connected in series between the base of the first-stage avalanche transistor and ground; The second-stage base differentiator circuit includes capacitor C2 and resistor R8, which are connected in series. The connection point of capacitor C2 and resistor R8 is the output terminal of the second-stage base differentiator circuit. The other end of capacitor C2 is connected to the collector of each avalanche transistor in the first stage, and the other end of resistor R8 is grounded. The second-stage avalanche transistor group consists of N avalanche transistors connected in parallel; the collector of each avalanche transistor in the second stage is connected to resistor R4, and DC voltage UCC is connected through resistor R4; the base of each avalanche transistor in the second stage is connected to the output terminal of the second-stage base differentiating circuit through its respective base resistor; the emitter of each avalanche transistor in the second stage is connected to the output terminal of the second-stage base differentiating circuit. One end of the main discharge capacitor is connected to the collector of each avalanche transistor in the second stage, and the other end serves as the output terminal of the pulse signal generation module. The second-stage discharge buffer circuit includes resistor R9 and fast recovery diode D1; resistor R9 and fast recovery diode D1 are connected in series between the output terminal of the first-stage pulse signal generation module and ground.
5. The partial discharge sensor performance testing system based on programmable discharge pulses according to claim 3, characterized in that, The DC voltage control module includes a digital potentiometer and an operational amplifier; The SCL and SDA terminals of the digital potentiometer are configured by a programmable input, and the output terminal is connected to an operational amplifier. The operational amplifier is connected to a proportional amplifier circuit to proportionally amplify the voltage output by the digital potentiometer and then output it to the pulse signal generation module to control the amplitude of the pulse output by the pulse signal generation module. The value of the programmable configuration word input at the SDA terminal corresponds to the amplitude of the pulse output by the pulse signal generation module, and the timing of the programmable control command at the SCL terminal corresponds to the timing of the pulse output by the pulse signal generation module.
6. The partial discharge sensor performance testing system based on programmable discharge pulses according to claim 3, characterized in that, The phase control module includes a trigger pulse generation circuit and a controllable timing circuit; The trigger pulse generation circuit includes a sinusoidal signal source and a zero-crossing detection circuit; The sinusoidal signal source generates a sinusoidal synchronization signal with the same frequency as the required trigger pulse and outputs it to the zero-crossing detection circuit; the zero-crossing detection circuit determines the phase zero point of the sinusoidal synchronization signal and outputs the trigger pulse sequence to the controllable timing circuit. The controllable timing circuit adjusts the pulse interval of the trigger pulse sequence according to the set timing length to form a delayed trigger pulse sequence output.
7. The partial discharge sensor performance testing system based on programmable discharge pulses according to claim 3, characterized in that, It also includes a waveform modulation module, which is used to programmatically adjust the parameters of the programmable pulse output by the pulse signal generation module, including pulse width, rise time, and oscillation frequency, to simulate the partial discharge signals of various signal parameter ranges encountered by the partial discharge sensor under test in actual detection.
8. The partial discharge sensor performance testing system based on programmable discharge pulses according to claim 7, characterized in that, The waveform modulation module includes a pulse width adjustment submodule, a rise time adjustment submodule, and an oscillation frequency adjustment submodule; wherein, The pulse width modulation (PWM) submodule includes multiple parallel RC damping circuits. Each RC damping circuit includes a resistor and capacitor connected in series between the output of the pulse signal generation module and ground, with the connection point of the resistor and capacitor serving as the output of the RC damping circuit. The outputs of multiple RC damping circuits are connected together to form the output of the PWM submodule. Each RC damping circuit also has a switch connected in series to control whether that circuit participates in pulse width modulation. By controlling the closing of different numbers of switches, the pulse width can be adjusted. The rise time adjustment submodule includes multiple resistors and capacitors arranged in parallel. These parallel resistors and capacitors are connected in series with their respective control switches and then connected between the output terminal of the pulse width adjustment submodule and ground, forming an RC differential circuit whose pulse rise time is controlled by the switches. By controlling the number of switches closed, the number of resistors and capacitors connected to the circuit to change the differential parameters is selected for adjusting the pulse rise time. The oscillation frequency adjustment submodule includes multiple parallel LC resonant circuits. The input signal in each LC resonant circuit is output after passing through a series inductor and capacitor. The output terminals of the multiple LC resonant circuits are connected together as the output terminal of the waveform modulation module. Each LC resonant circuit also has a switch connected in series to control whether the LC resonant circuit participates in the oscillation frequency adjustment. By controlling the closing of different numbers of switches, the pulse oscillation frequency can be adjusted.
9. A performance testing method for a partial discharge sensor performance testing system based on programmable discharge pulses as described in any one of claims 1-8, characterized in that, include: Step S1: Adjust the parameters of the discharge pulse generating device to ensure that the discharge pulse generating device can output a partial discharge signal with a set amplitude, phase and frequency; Step S2: Measure the partial discharge signal using the partial discharge sensor under test; Step S3: The performance testing unit receives the partial discharge signal and the measurement signal, performs time-domain and frequency-domain processing, calculates the correlation coefficient, transfer function, rise time error and DTW distance of the partial discharge signal and the detection signal, and performs a comprehensive test of the partial discharge sensor, including measurement accuracy, frequency response characteristics, transient response capability and signal fidelity.
10. The performance testing method for the partial discharge sensor performance testing system based on programmable discharge pulses according to claim 9, characterized in that, Step S3 includes: Step 301: Perform frequency domain transformation on the partial discharge signal and the measurement signal respectively to obtain the frequency domain signals; Step 302: Calculate and output the correlation coefficient between the partial discharge signal and the measurement signal in the time domain to measure the accuracy of the partial discharge sensor under test; Step 303: Solve for the transfer function of the partial discharge sensor under test in the frequency domain. The output transfer function curve characterizes the frequency response characteristics of the partial discharge sensor under test, and the average gain of the output transfer function characterizes the gain impedance of the partial discharge sensor under test. Step 304: Solve for the pulse rise time of the partial discharge signal and the measurement signal in the time domain, and calculate and output the pulse rise time error of the partial discharge signal and the corresponding measurement signal to characterize the transient response capability of the partial discharge sensor under test. Step 305: Detect the pulse waveform fidelity of the partial discharge signal and the measurement signal in the time domain to obtain the DTW distance between the two signals, which characterizes the signal fidelity of the partial discharge sensor under test.