An electrical parameter monitoring system for a lightning arrester action load test

Abstract

The application provides an electrical parameter monitoring system for lightning arrester action load test, and relates to the technical field of lightning arrester. The system comprises a multi-channel automatic switching acquisition circuit, an acquisition card, a controller and a data analysis unit. The multi-channel automatic switching acquisition circuit is connected with the data analysis unit through the acquisition card. The controller is connected with the multi-channel automatic switching acquisition circuit. The electrical parameter monitoring system for lightning arrester action load test can improve the electrical parameter monitoring efficiency and accuracy of lightning arrester action load test.

Description

Technical Field

[0001] This invention relates to the field of surge arrester technology, and more specifically to an electrical parameter monitoring system for surge arrester operation load testing. Background Technology

[0002] The requirements for surge arrester operating load tests include: applying a power frequency voltage to the test object in two stages within 100ms after the impulse is applied. In the first stage, the rated voltage is applied to the test object for a specified time, typically ranging from 0.1s to 3600s. In the second stage, a continuous operating voltage is applied to the test object for at least 30 minutes, during which the power consumption, resistive current, or temperature trend of the test object must be continuously monitored.

[0003] In the first stage, the focus is on whether the applied voltage duration and value meet the requirements. Due to the inaccurate measurement of the applied voltage duration using counters and the resulting voltage waveform distortion, an oscilloscope is currently used to read, store, and analyze the data from the first stage. Furthermore, in the first and second stages, the current variation of the test specimen ranges from microamps to amperes due to differences in specimen characteristics, applied voltage, and temperature variations. Therefore, using a suitable current acquisition device throughout the experiment is fundamental to ensuring the validity of the test data. During this process, the main focus is on the trend of power dissipation or resistive current changes over time, and both voltage and current need to be displayed in real time.

[0004] Currently, surge arrester operational load tests typically employ a combination of oscilloscopes and power consumption measurement systems to meet the monitoring requirements of the first and second stages, respectively. Throughout the entire test, the current measuring devices are manually selected by the test personnel, with a maximum of two different ranges used for each stage. However, this combination of oscilloscopes and power consumption measurement systems involves multiple instruments, requiring multiple manual operations for each instrument, increasing the possibility of human error leading to missing measurement data and adding to the manual workload. Furthermore, the current current measuring device selection strategy cannot guarantee the accuracy of data acquisition when the current varies from microamperes to amperes. Summary of the Invention

[0005] To address the problems in the prior art, embodiments of the present invention provide an electrical parameter monitoring system for surge arrester operation load testing, which can at least partially solve the problems existing in the prior art.

[0006] On the one hand, the present invention proposes an electrical parameter monitoring system for surge arrester operation load test, including a multi-channel automatic switching acquisition circuit, an acquisition card, a controller and a data analysis unit;

[0007] The multi-channel automatic switching acquisition loop is connected to the data analysis unit via the acquisition card; the controller is connected to the multi-channel automatic switching acquisition loop.

[0008] The multi-channel automatic switching acquisition circuit is used to provide multiple current measurement ranges; the multi-channel automatic switching acquisition circuit includes multiple measurement circuits connected in parallel; one end of each measurement circuit is provided with a full current signal input port, and the other end of each measurement circuit is connected to the acquisition card;

[0009] Each measurement circuit includes a measurement range resistance value and a relay connected in sequence, and the relays in each measurement circuit are connected to the controller; the measurement range resistance values ​​of each measurement circuit are different.

[0010] The acquisition card is used to acquire the voltage signal and reference capacitor current signal of the surge arrester, as well as the full current signal of the surge arrester through the multi-channel automatic switching acquisition circuit;

[0011] The controller is used to switch the conduction state of each measurement circuit of the multi-channel automatic switching acquisition circuit according to the current full current signal amplitude, so as to control the current full current signal amplitude to be within the current measurement range required by the current measurement level of the measurement circuit currently conducting the relay.

[0012] The data analysis unit is used to obtain the electrical parameter monitoring results of the surge arrester's operating load test based on the surge arrester's reference capacitor current signal, voltage signal, and the current full current signal corresponding to the current full current signal amplitude within the required measurement range of the current measurement range.

[0013] The multi-channel automatic switching acquisition circuit also includes a protection circuit connected in parallel with each measurement circuit;

[0014] The protection circuit includes a first diode and a second diode connected in reverse parallel.

[0015] The data analysis unit is also used for:

[0016] The monitoring results of electrical parameters during surge arrester operation load tests are displayed visually.

[0017] The electrical parameter monitoring system also includes a router;

[0018] The router is connected to the data analysis unit and is used to transmit the electrical parameter monitoring results of the surge arrester operation load test.

[0019] On one hand, the present invention proposes a method for monitoring electrical parameters of a surge arrester operating load test using the above-mentioned surge arrester operating load test electrical parameter monitoring system, comprising:

[0020] The voltage signal and reference capacitor current signal of the surge arrester are collected, as well as the full current signal of the surge arrester are collected through the multi-channel automatic switching acquisition circuit;

[0021] Based on the current full current signal amplitude, the conduction state of each measurement circuit of the multi-channel automatic switching acquisition circuit is switched to control the current full current signal amplitude to be within the current measurement range required by the current measurement level of the measurement circuit currently conducting.

[0022] Based on the surge arrester's reference capacitance current signal, voltage signal, and the current full current signal corresponding to the amplitude of the current full current signal within the required measurement range of the current measurement range, the electrical parameter monitoring results of the surge arrester's operating load test are obtained.

[0023] The step of switching the conduction state of each measurement circuit of the multi-channel automatic switching acquisition circuit according to the current full current signal amplitude includes:

[0024] If it is determined that the current full current signal amplitude is less than or equal to the minimum endpoint value of the current measurement range required by the current measurement range, then the first switching operation is periodically performed on the measurement circuit that is currently conducting the relay until the current full current signal amplitude is within the current measurement range required by the current measurement range of the measurement circuit that is currently conducting the relay.

[0025] The first switching operation includes disconnecting the currently active relay and connecting the relay at a lower current measurement level.

[0026] The step of switching the conduction state of each measurement circuit of the multi-channel automatic switching acquisition circuit according to the current full current signal amplitude includes:

[0027] If it is determined that the current full current signal amplitude is greater than or equal to the maximum endpoint value of the current measurement range required by the current measurement range, then the second switching operation is periodically performed on the measurement circuit that is currently conducting the relay until the current full current signal amplitude is within the current measurement range required by the current measurement range of the measurement circuit that is currently conducting the relay.

[0028] The second switching operation includes disconnecting the currently active relay and connecting the relay of the next higher current measurement range.

[0029] The electrical parameter monitoring results include resistive current waveforms; correspondingly, obtaining the electrical parameter monitoring results includes:

[0030] The reference capacitor current waveform is obtained based on the reference capacitor current signal;

[0031] The peak point of the reference capacitor current waveform is taken as the zero point of the resistive current waveform.

[0032] Multiply the reference capacitor current by the ratio of the peak value of the actual capacitor current to the peak value of the reference capacitor current to obtain the adjusted reference capacitor current. Subtract the full current waveform from the adjusted reference capacitor current waveform to obtain the resistive current waveform.

[0033] The electrical parameter monitoring results include resistive current waveforms; correspondingly, obtaining the electrical parameter monitoring results includes:

[0034] When the harmonic content of the voltage waveform is less than 5% of the fundamental frequency, the voltage waveform is advanced by 90° to generate the current waveform to be processed. A coefficient is used to multiply the current waveform to be processed, and then the coefficient is dynamically adjusted so that the difference between the current waveform to be processed and the full current waveform at the peak of the voltage is 0, thus obtaining the resistive current waveform.

[0035] The electrical parameter monitoring results include resistive current waveforms; correspondingly, obtaining the electrical parameter monitoring results includes:

[0036] When the harmonic content of the voltage waveform is higher than 5% of the fundamental waveform, the voltage waveform is expanded into a Fourier series waveform to obtain several levels of voltage Fourier series waveforms; and the total current waveform is decomposed into a series and several levels of voltage Fourier series waveforms that correspond one-to-one with the current Fourier series waveforms.

[0037] The Fourier series waveforms of each current are extracted according to the phase angle of the voltage waveform to obtain the extracted Fourier series waveforms of each current that are in phase with the voltage waveform.

[0038] By superimposing the waveforms extracted from the Fourier series of each current, the resistive current waveform is obtained.

[0039] The electrical parameter monitoring system for surge arrester operation load test provided in this embodiment of the invention includes a multi-channel automatic switching acquisition circuit, an acquisition card, a controller, and a data analysis unit. The multi-channel automatic switching acquisition circuit is connected to the data analysis unit via the acquisition card. The controller is connected to the multi-channel automatic switching acquisition circuit. The multi-channel automatic switching acquisition circuit provides multiple current measurement ranges. The multi-channel automatic switching acquisition circuit includes multiple parallel measurement circuits. One end of each measurement circuit is provided with a full current signal input port, and the other end of each measurement circuit is connected to the acquisition card. Each measurement circuit includes a measurement range resistance value and a relay connected in sequence, and the relays in each measurement circuit are connected to the controller. The measurement range resistance values ​​of each measurement circuit are different. The acquisition card is used to acquire the voltage signal and reference capacitor current signal of the surge arrester, as well as the total current signal of the surge arrester through the multi-channel automatic switching acquisition circuit. The controller is used to switch the conduction state of each measurement circuit of the multi-channel automatic switching acquisition circuit according to the current amplitude of the total current signal, so as to control the current amplitude of the total current signal to be within the current measurement range required by the current measurement range of the measurement circuit currently conducting. The data analysis unit is used to obtain the electrical parameter monitoring results of the surge arrester operation load test based on the reference capacitor current signal, voltage signal, and the current total current signal corresponding to the current amplitude of the current total current signal within the current measurement range required by the current measurement range, which can improve the efficiency and accuracy of electrical parameter monitoring of the surge arrester operation load test.

[0040] The present invention provides a method for monitoring electrical parameters of a surge arrester operating load test using an electrical parameter monitoring system. The method includes acquiring the voltage signal and reference capacitance current signal of the surge arrester, and acquiring the total current signal of the surge arrester through a multi-channel automatic switching acquisition circuit. Based on the current amplitude of the total current signal, the method switches the conduction state of each measurement circuit in the multi-channel automatic switching acquisition circuit to control the current amplitude of the total current signal to be within the current measurement range required by the current measurement setting of the currently conducting measurement circuit. Based on the reference capacitance current signal, voltage signal, and the current total current signal corresponding to the current amplitude of the total current signal within the required measurement range of the current measurement setting, the method obtains the electrical parameter monitoring results of the surge arrester operating load test. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings:

[0042] Figure 1 This is a schematic diagram of the electrical parameter monitoring system for surge arrester operation load test provided in an embodiment of the present invention.

[0043] Figure 2 This is a schematic diagram of the structure of a multi-channel automatic switching acquisition loop provided in an embodiment of the present invention.

[0044] Figure 3 This is a schematic diagram of the process for switching different current measurement levels according to an embodiment of the present invention.

[0045] Figure 4 This is a schematic diagram of analog waveform discretization provided in an embodiment of the present invention. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Here, the illustrative embodiments and descriptions of the present invention are used to explain the present invention, but are not intended to limit the present invention. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be arbitrarily combined with each other.

[0047] Explanation of relevant terms:

[0048] Total current: The current flowing through the surge arrester when a power frequency voltage is applied to it.

[0049] Resistive current: The resistive component of the surge arrester in the total current.

[0050] Power consumption: The integral of the instantaneous values ​​of resistive current and voltage of the surge arrester.

[0051] Operating load test: This test simulates the surge arrester being subjected to a series of current surges and power frequency overvoltages during an overvoltage process. The test mainly consists of an impulse current test and a thermal stability test.

[0052] Thermal stability test: In the final stage of the operating load test, the rated voltage and continuous operating voltage are applied to the test specimen for a certain period of time, and the test specimen's power consumption, resistive current or temperature trend is observed during this period.

[0053] Figure 1 This is a schematic diagram of the electrical parameter monitoring system for surge arrester operation load testing provided in an embodiment of the present invention, as shown below. Figure 1 As shown, the electrical parameter monitoring system for surge arrester operation load test provided in this embodiment of the invention includes a multi-channel automatic switching acquisition circuit 1, an acquisition card 2, a controller 3, and a data analysis unit 4;

[0054] The multi-channel automatic switching acquisition loop 1 is connected to the data analysis unit 4 via the acquisition card 2; the controller 3 is connected to the multi-channel automatic switching acquisition loop 1.

[0055] The multi-channel automatic switching acquisition circuit 1 is used to provide multiple current measurement ranges; the multi-channel automatic switching acquisition circuit 1 includes multiple measurement circuits connected in parallel; one end of each measurement circuit is provided with a full current signal input port, and the other end of each measurement circuit is connected to the acquisition card 2;

[0056] Each measurement circuit includes a measurement range resistance value and a relay connected in sequence, and the relay in each measurement circuit is connected to the controller 3; the measurement range resistance values ​​of each measurement circuit are different; for example... Figure 2 As shown, there are 10 measurement circuits, providing 10 current measurement ranges. The resistance values ​​for each measurement range are 500kΩ, 50kΩ, 5kΩ, 500Ω, 50Ω, 5Ω, 0.5Ω, 50mΩ, 5mΩ, and 1mΩ, respectively, to measure different range current values. Each resistor is connected to a corresponding relay (KM1~KM10), and the 10 relays control the on / off state to achieve switching between different current measurement ranges.

[0057] The relay switches of the multi-channel automatic switching acquisition loop 1 and the activation of each measurement loop can all be controlled by the controller 3. The multi-channel automatic switching acquisition loop 1 can be activated in two ways: permanent activation and activation upon trigger signal.

[0058] When permanently started, the relay switch of the multi-channel automatic switching acquisition circuit 1 is in the normally closed state; when started by a trigger signal, the relay switch is closed under the control of the inrush current ignition trigger signal.

[0059] The acquisition card 2 is used to acquire the voltage signal and reference capacitor current signal of the surge arrester, as well as the total current signal of the surge arrester through the multi-channel automatic switching acquisition circuit 1. The voltage, total current and capacitive current acquired by the acquisition card 2 can be analyzed to extract data such as the resistive current flowing through the surge arrester and the instantaneous power of the surge arrester. Then, a curve with time on the horizontal axis and current or power value on the vertical axis can be plotted on the computer interface for real-time display.

[0060] In addition, the acquisition card 2 collects multiple channels of analog data in real time. The host computer interface communicates with the acquisition card 2 in real time to obtain the real-time acquired signals, such as voltage signals, total current signals and capacitive current signals. The host computer curve display control displays the real-time waveforms of the surge arrester's electrical parameters. The software backend calculates the relationship between waveforms of different channels, thereby generating the digital signal waveforms of power and resistive current that need to be calculated and displayed on the front panel.

[0061] The controller 3 is used to switch the conduction state of each measurement circuit of the multi-channel automatic switching acquisition circuit 1 according to the current full current signal amplitude, so as to control the current full current signal amplitude to be within the current measurement range required by the current measurement level of the measurement circuit currently conducting. The controller 3 can be a PLC controller. The current measurement range required by the current measurement level can be set independently according to the actual situation, and can be selected from 10% to 100%.

[0062] The data analysis unit 4 is used to obtain the electrical parameter monitoring results of the surge arrester's operating load test based on the surge arrester's reference capacitor current signal, voltage signal, and the current full current signal corresponding to the current full current signal amplitude within the required measurement range of the current measurement setting. The electrical parameter monitoring results may include one or more of the following: voltage waveform, full current waveform, resistive current waveform, voltage peak value, current peak value, voltage RMS value, current RMS value, and voltage peak value and... The ratio, peak current and The ratio of the resistive current to the time-instantaneous power consumption, the trend of power consumption over time, and the trend of resistive current over time are all considered. The trend of resistive current over time can be represented by the resistive current waveform.

[0063] The multi-channel automatic switching acquisition loop 1 also includes a protection circuit connected in parallel with each measurement loop;

[0064] The protection circuit includes a first diode and a second diode connected in reverse parallel. For example... Figure 2 The two diodes shown can serve as the first and second diodes for each other. During current acquisition and measurement, the diodes are connected in reverse parallel as a protection circuit. Utilizing the forward conduction curve of the diodes, even when the actual current is much greater than the selected current measurement range, the output of the protection circuit will not exceed the forward conduction voltage of the diodes. Furthermore, because the forward conduction current of the diodes is large, the protection circuit can withstand high currents for extended periods without damage.

[0065] The data analysis unit 4 is also used for:

[0066] The monitoring results of electrical parameters during surge arrester operation load tests are displayed visually.

[0067] Data analysis unit 4 can display the monitoring results of electrical parameters of the surge arrester under operating load test in real time, such as voltage waveform, full current waveform, resistive current waveform, voltage peak value, current peak value, voltage RMS value, current RMS value, voltage peak value to current ratio, current peak value to current ratio, instantaneous power, periodic power consumption, power consumption trend over time, and resistive current trend over time.

[0068] The data analysis unit 4 is also used to acquire signals within a specified time period, extract the monitoring results of the electrical parameters of the surge arrester during the specified time period from the stored monitoring results of the electrical parameters of the surge arrester during the operating load test based on the signals within the specified time period, and visualize them, as well as to widen and scale the waveforms in the monitoring results of the electrical parameters of the operating load test on the horizontal and vertical axes.

[0069] The electrical parameter monitoring system also includes router 5;

[0070] The router 5 is connected to the data analysis unit 4 and is used to transmit the electrical parameter monitoring results of the surge arrester's operating load test. The electrical parameter monitoring system also includes a power supply, router 5, and a housing; router 5, data acquisition card 2, controller 3, and data analysis unit 4 are all connected to the power supply; the housing covers the power supply, router 5, multi-channel automatic switching acquisition circuit 1, data acquisition card 2, controller 3, and data analysis unit 4; router 5 is connected to data analysis unit 1 and is used to transmit the electrical parameter monitoring results of the surge arrester's operating load test.

[0071] The electrical parameter monitoring system for surge arrester operation load test provided in this embodiment of the invention includes a multi-channel automatic switching acquisition circuit, an acquisition card, a controller, and a data analysis unit. The multi-channel automatic switching acquisition circuit is connected to the data analysis unit via the acquisition card. The controller is connected to the multi-channel automatic switching acquisition circuit. The multi-channel automatic switching acquisition circuit provides multiple current measurement ranges. The multi-channel automatic switching acquisition circuit includes multiple parallel measurement circuits. One end of each measurement circuit is provided with a full current signal input port, and the other end of each measurement circuit is connected to the acquisition card. Each measurement circuit includes a measurement range resistance value and a relay connected in sequence, and the relays in each measurement circuit are connected to the controller. The measurement range resistance values ​​of each measurement circuit are different. The acquisition card is used to acquire the voltage signal and reference capacitor current signal of the surge arrester, as well as the total current signal of the surge arrester through the multi-channel automatic switching acquisition circuit. The controller is used to switch the conduction state of each measurement circuit of the multi-channel automatic switching acquisition circuit according to the current amplitude of the total current signal, so as to control the current amplitude of the total current signal to be within the current measurement range required by the current measurement range of the measurement circuit currently conducting. The data analysis unit is used to obtain the electrical parameter monitoring results of the surge arrester operation load test based on the reference capacitor current signal, voltage signal, and the current total current signal corresponding to the current amplitude of the current total current signal within the current measurement range required by the current measurement range, which can improve the efficiency and accuracy of electrical parameter monitoring of the surge arrester operation load test.

[0072] Furthermore, the multi-channel automatic switching acquisition loop also includes a protection circuit connected in parallel with each measurement loop;

[0073] The protection circuit includes a first diode and a second diode connected in reverse parallel. This can be referred to the above embodiment for further explanation, and will not be repeated here.

[0074] Furthermore, the data analysis unit is also used for:

[0075] The monitoring results of electrical parameters during the surge arrester's operational load test are displayed visually. Refer to the above embodiments for further explanation; details will not be repeated here.

[0076] Furthermore, the electrical parameter monitoring system also includes a router;

[0077] The router is connected to the data analysis unit and is used to transmit the electrical parameter monitoring results of the surge arrester operation load test. This can be referred to the above embodiment for further explanation, and will not be repeated here.

[0078] This invention provides a method for monitoring electrical parameters during a surge arrester operating load test using the aforementioned surge arrester operating load test electrical parameter monitoring system, comprising:

[0079] The voltage signal and reference capacitor current signal of the surge arrester are collected, as well as the full current signal of the surge arrester are collected through the multi-channel automatic switching acquisition circuit;

[0080] Based on the current full current signal amplitude, the conduction state of each measurement circuit of the multi-channel automatic switching acquisition circuit is switched to control the current full current signal amplitude within the current measurement range required by the current measurement level of the measurement circuit currently conducting with the relay; the switching of the conduction state of each measurement circuit of the multi-channel automatic switching acquisition circuit based on the current full current signal amplitude includes:

[0081] If it is determined that the current full current signal amplitude is less than or equal to the minimum endpoint value of the current measurement range required by the current measurement range, then the first switching operation is periodically performed on the measurement circuit that is currently conducting the relay until the current full current signal amplitude is within the current measurement range required by the current measurement range of the measurement circuit that is currently conducting the relay.

[0082] The first switching operation includes disconnecting the currently active relay and connecting the relay at a lower current measurement level.

[0083] The step of switching the conduction state of each measurement circuit of the multi-channel automatic switching acquisition circuit according to the current full current signal amplitude includes:

[0084] If it is determined that the current full current signal amplitude is greater than or equal to the maximum endpoint value of the current measurement range required by the current measurement range, then the second switching operation is periodically performed on the measurement circuit that is currently conducting the relay until the current full current signal amplitude is within the current measurement range required by the current measurement range of the measurement circuit that is currently conducting the relay.

[0085] The second switching operation includes disconnecting the currently active relay and connecting the relay of the next higher current measurement range.

[0086] The explanation is as follows:

[0087] When the current full current signal amplitude is within 10% to 100% of the current measurement range required by the current measurement range of the measurement circuit currently conducting, the conduction state of the relays in each measurement circuit is not changed.

[0088] When the current full current signal amplitude is less than 10% of the required measurement range of the current measurement range of the measurement circuit currently conducting, repeat the first switching operation until the current full current signal amplitude is between 10% and 100% of the required measurement range of the current measurement range of the measurement circuit currently conducting; wherein, the first switching operation includes: disconnecting the currently conducting relay and connecting the relay of the lower current measurement range.

[0089] When the current full current signal amplitude is greater than 100% of the required measurement range of the current measurement range of the measurement circuit currently conducting, repeat the second switching operation until the current full current signal amplitude is between 10% and 100% of the required measurement range of the current measurement range of the measurement circuit currently conducting; wherein, the second switching operation includes: disconnecting the currently conducting relay and connecting the relay of the next higher current measurement range.

[0090] like Figure 3 As shown, before the multi-channel automatic switching acquisition circuit starts working, it performs the first stage (Ur stage) measurement based on a manually set current measurement range. After being put into use, when the measured value is within 10% to 100% of the required measurement range for that current measurement range, it will not switch. When the value is below 10% or above 100%, it will automatically switch to a smaller or larger current measurement range. For example, if the current measurement range is 1A, then the required measurement range of 10% to 100% is 0.1 to 1A. If the value is less than 0.1A, the current measurement range will be lowered; if the value is higher than 1A, the current measurement range will be higher.

[0091] Based on the surge arrester's reference capacitance current signal, voltage signal, and the current total current signal corresponding to the amplitude of the current total current signal within the required measurement range of the current measurement setting, the electrical parameter monitoring results of the surge arrester's operating load test are obtained. The electrical parameter monitoring results include a resistive current waveform; correspondingly, obtaining the electrical parameter monitoring results includes:

[0092] The reference capacitor current waveform is obtained based on the reference capacitor current signal;

[0093] The peak point of the reference capacitor current waveform is taken as the zero point of the resistive current waveform.

[0094] Multiplying the reference capacitor current by the ratio of the peak value of the actual capacitor current to the peak value of the reference capacitor current yields the adjusted reference capacitor current. Subtracting the full current waveform from the adjusted reference capacitor current waveform gives the resistive current waveform. This step is the compensation method for obtaining the resistive current waveform. The basic principle of the compensation method is: the peak point of the reference capacitor current waveform is considered to be the zero point of the resistive current waveform. Based on this, by adjusting the value assigned to the reference capacitor current waveform, and then subtracting the full current waveform from the adjusted reference capacitor current waveform, the resistive current waveform can be obtained.

[0095] The method for adjusting the value of the reference capacitor current waveform is as follows: since the phase difference between the capacitive current and the resistive current is 90°, when the capacitor current is at its maximum, the resistive current is zero. Therefore, the total current at this time is the capacitive current; the amplitude of the total current at the peak of the capacitive current is the actual peak value of the capacitive current at this time.

[0096] The electrical parameter monitoring results include resistive current waveforms; correspondingly, obtaining the electrical parameter monitoring results includes:

[0097] When the harmonic content of the voltage waveform is less than 5% of the fundamental frequency, the voltage waveform is led by 90° to generate the current waveform to be processed. A coefficient is then multiplied with the current waveform to be processed, and the coefficient is dynamically adjusted so that the difference between the current waveform to be processed and the full current waveform at the voltage peak is 0, thus obtaining the resistive current waveform. The peak correspondence method is applied when the harmonic content of the voltage waveform is less than 5% of the fundamental frequency. In this scenario, the reference capacitor current waveform can be considered to be basically a standard sine wave. It can be assumed that the capacitive current waveform is 0 at the voltage peak. The voltage waveform is led by 90° to generate the current waveform to be processed. A coefficient is then multiplied with this current waveform to be processed, and the coefficient is dynamically adjusted so that the difference between the current waveform to be processed and the full current waveform is 0 at the voltage peak. The current waveform to be processed at this point is taken as the resistive current waveform.

[0098] The electrical parameter monitoring results include resistive current waveforms; correspondingly, obtaining the electrical parameter monitoring results includes:

[0099] When the harmonic content of the voltage waveform is higher than 5% of the fundamental waveform, the voltage waveform is expanded into a Fourier series waveform to obtain several levels of voltage Fourier series waveforms; and the total current waveform is decomposed into a series and several levels of voltage Fourier series waveforms that correspond one-to-one with the current Fourier series waveforms.

[0100] The Fourier series waveforms of each current are extracted according to the phase angle of the voltage waveform to obtain the extracted Fourier series waveforms of each current that are in phase with the voltage waveform.

[0101] The resistive current waveform is obtained by superimposing the waveforms extracted from the Fourier series of each current. The Fourier transform method is applied when the harmonic content of the voltage waveform is higher than 5% of the fundamental frequency. In this scenario, the reference capacitor current waveform and voltage waveform differ significantly. In this case, the voltage waveform can be expanded into a Fourier series, and the total current waveform can also be branched into Fourier series, corresponding one-to-one with the voltage waveform series. The total current waveform series is divided into two parts according to the phase angle of the voltage waveform: one part is the waveform in phase with the voltage waveform, which is the sub-resistive current waveform; the other part is the waveform with a 90° phase angle difference from the voltage waveform, which is the capacitive current waveform. The in-phase waveforms in all series are superimposed, i.e., all sub-resistive current waveforms are superimposed to obtain the resistive current waveform.

[0102] The data acquisition card acquires the voltage and total current signals of the surge arrester in real time. Since the acquisition card directly acquires the analog parameter waveforms, the voltage and total current waveforms can be obtained directly. Then, based on this, the actual analog parameter waveforms are discretized, and the peak value and peak value ratio can be calculated using software. The values ​​and valid values ​​of the parameters.

[0103] For details, see Figure 4 Peak value and peak ratio The value can be read directly from the discretized array: Upeak = Max[y1,y2,y3...yn], where n is the total sample value in one cycle; yi is the i-th sample value of the voltage waveform or current waveform, i∈(1~n).

[0104] The effective value of voltage or the effective value of current is obtained by the following formula:

[0105]

[0106] The instantaneous power is obtained by multiplying the analog voltage and analog current values ​​at the same moment; the periodic power consumption is obtained by integrating the instantaneous power over one period.

[0107] Specifically, voltage and current points are simultaneously collected, and the product of Ui × Ii × Δt is multiplied on the time axis to calculate the instantaneous power. Integrating the product of Ui × Ii × Δt over one period yields the total power for that period, which in turn allows for the calculation of the equivalent power of the sample. Here, Ui represents the instantaneous voltage value, Ii represents the instantaneous total current value, and Δt represents the time interval between adjacent sampling points.

[0108] Furthermore, the step of switching the conduction state of each measurement circuit of the multi-channel automatic switching acquisition circuit according to the current full current signal amplitude includes:

[0109] If it is determined that the current full current signal amplitude is less than or equal to the minimum endpoint value of the current measurement range required by the current measurement setting, then the first switching operation is periodically performed on the measurement circuit currently connected by the relay until the current full current signal amplitude is within the current measurement range required by the current measurement setting of the measurement circuit currently connected by the relay; this can be referred to the above embodiment for explanation, and will not be repeated here.

[0110] The first switching operation includes disconnecting the currently active relay and connecting the relay at the lower current measurement level. This can be referred to the above embodiment for further explanation and will not be repeated here.

[0111] Furthermore, the step of switching the conduction state of each measurement circuit of the multi-channel automatic switching acquisition circuit according to the current full current signal amplitude includes:

[0112] If it is determined that the current full current signal amplitude is greater than or equal to the maximum endpoint value of the current measurement range required by the current measurement setting, then the second switching operation is periodically performed on the measurement circuit currently connected by the relay until the current full current signal amplitude is within the current measurement range required by the current measurement setting of the measurement circuit currently connected by the relay; this can be referred to the above embodiment for explanation, and will not be repeated here.

[0113] The second switching operation includes disconnecting the currently active relay and connecting the relay of the next higher current measurement range. This can be referred to the above embodiment for explanation, and will not be repeated here.

[0114] Furthermore, the electrical parameter monitoring results include resistive current waveforms; correspondingly, acquiring the electrical parameter monitoring results includes:

[0115] The reference capacitor current waveform is obtained based on the reference capacitor current signal; this can be referred to the above embodiment for explanation, and will not be repeated here.

[0116] The peak point of the reference capacitor current waveform is taken as the zero point of the resistive current waveform; this can be referred to the above embodiment for explanation, and will not be repeated here.

[0117] Multiply the reference capacitor current by the ratio of the peak value of the actual capacitor current to the peak value of the reference capacitor current to obtain the adjusted reference capacitor current. Subtract the adjusted reference capacitor current waveform from the full current waveform to obtain the resistive current waveform. Refer to the above embodiment for further details.

[0118] Furthermore, the electrical parameter monitoring results include resistive current waveforms; correspondingly, acquiring the electrical parameter monitoring results includes:

[0119] When the harmonic content of the voltage waveform is less than 5% of the fundamental frequency, the voltage waveform is led by 90° to generate the current waveform to be processed. A coefficient is then multiplied by the current waveform to be processed, and the coefficient is dynamically adjusted so that the difference between the current waveform to be processed and the full current waveform at the peak voltage is 0, thus obtaining the resistive current waveform. This can be referred to the above embodiment for explanation, and will not be repeated here.

[0120] Furthermore, the electrical parameter monitoring results include resistive current waveforms; correspondingly, acquiring the electrical parameter monitoring results includes:

[0121] When the harmonic content of the voltage waveform is higher than 5% of the fundamental frequency, the voltage waveform is expanded into a Fourier series waveform to obtain several levels of voltage Fourier series waveforms; and the total current waveform is decomposed into a series and several levels of voltage Fourier series waveforms corresponding to current Fourier series waveforms; the above embodiments can be referred to for explanation, and will not be repeated here.

[0122] The Fourier series waveforms of each current are extracted according to the phase angle of the voltage waveform to obtain the extracted Fourier series waveforms of each current that are in phase with the voltage waveform; this can be referred to the above embodiment for explanation, and will not be repeated here.

[0123] The waveforms extracted from the Fourier series of each current are superimposed to obtain the resistive current waveform. This can be referred to the above embodiment for explanation, and will not be repeated here.

[0124] The electrical parameter monitoring method for surge arrester operating load tests using an electrical parameter monitoring system provided in this invention effectively reduces the possibility of missing measurement data due to human error, and also reduces the burden of manual operation, compared to existing collaborative monitoring using multiple instruments. Furthermore, by switching the conduction state of each measurement circuit in the multi-channel automatic switching acquisition circuit according to the current full current signal amplitude using a controller, the switching of current measurement ranges across different ranges is achieved, ensuring the accuracy of data acquisition when the current varies from microamperes to amperes, thus guaranteeing the accuracy of the test data.

[0125] The present invention provides a method for monitoring electrical parameters of a surge arrester operating load test using an electrical parameter monitoring system. The method includes acquiring the voltage signal and reference capacitance current signal of the surge arrester, and acquiring the total current signal of the surge arrester through a multi-channel automatic switching acquisition circuit. Based on the current amplitude of the total current signal, the method switches the conduction state of each measurement circuit in the multi-channel automatic switching acquisition circuit to control the current amplitude of the total current signal to be within the current measurement range required by the current measurement setting of the currently conducting measurement circuit. Based on the reference capacitance current signal, voltage signal, and the current total current signal corresponding to the current amplitude of the total current signal within the required measurement range of the current measurement setting, the method obtains the electrical parameter monitoring results of the surge arrester operating load test.

[0126] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0127] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0128] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0129] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0130] In the description of this specification, the references to terms such as "an embodiment," "a specific embodiment," "some embodiments," "for example," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0131] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An electrical parameter monitoring system for surge arrester operating load test, characterized in that, It includes a multi-channel automatic switching acquisition loop, acquisition card, controller, and data analysis unit; The multi-channel automatic switching acquisition loop is connected to the data analysis unit via the acquisition card; the controller is connected to the multi-channel automatic switching acquisition loop. The multi-channel automatic switching acquisition circuit is used to provide multiple current measurement ranges; the multi-channel automatic switching acquisition circuit includes multiple measurement circuits connected in parallel; one end of each measurement circuit is provided with a full current signal input port, and the other end of each measurement circuit is connected to the acquisition card; Each measurement circuit includes a measurement range resistance value and a relay connected in sequence, and the relays in each measurement circuit are connected to the controller; the measurement range resistance values ​​of each measurement circuit are different. The acquisition card is used to acquire the voltage signal and reference capacitor current signal of the surge arrester, as well as the full current signal of the surge arrester through the multi-channel automatic switching acquisition circuit; The controller is used to switch the conduction state of each measurement circuit of the multi-channel automatic switching acquisition circuit according to the current full current signal amplitude, so as to control the current full current signal amplitude to be within the current measurement range required by the current measurement level of the measurement circuit currently conducting the relay. The data analysis unit is used to obtain the electrical parameter monitoring results of the surge arrester's operating load test based on the surge arrester's reference capacitor current signal, voltage signal, and the current full current signal corresponding to the current full current signal amplitude within the required measurement range of the current measurement range.

2. The electrical parameter monitoring system for surge arrester operation load test according to claim 1, characterized in that, The multi-channel automatic switching acquisition loop also includes a protection circuit connected in parallel with each measurement loop; The protection circuit includes a first diode and a second diode connected in reverse parallel.

3. The electrical parameter monitoring system for surge arrester operation load test according to claim 1, characterized in that, The data analysis unit is also used for: The monitoring results of electrical parameters during surge arrester operation load tests are displayed visually.

4. The electrical parameter monitoring system for surge arrester operating load test according to any one of claims 1 to 3, characterized in that, The electrical parameter monitoring system also includes a router; The router is connected to the data analysis unit and is used to transmit the electrical parameter monitoring results of the surge arrester operation load test.

5. A method for monitoring electrical parameters during a surge arrester operating load test using the electrical parameter monitoring system for surge arrester operating load test as described in claim 1, characterized in that, The electrical parameter monitoring methods for the surge arrester operating load test include: The voltage signal and reference capacitor current signal of the surge arrester are collected, as well as the full current signal of the surge arrester are collected through the multi-channel automatic switching acquisition circuit; Based on the current full current signal amplitude, the conduction state of each measurement circuit of the multi-channel automatic switching acquisition circuit is switched to control the current full current signal amplitude to be within the current measurement range required by the current measurement level of the measurement circuit currently conducting. Based on the surge arrester's reference capacitance current signal, voltage signal, and the current full current signal corresponding to the amplitude of the current full current signal within the required measurement range of the current measurement range, the electrical parameter monitoring results of the surge arrester's operating load test are obtained.

6. The method for monitoring electrical parameters of a surge arrester under operating load according to claim 5, characterized in that, The step of switching the conduction state of each measurement circuit of the multi-channel automatic switching acquisition circuit according to the current full current signal amplitude includes: If it is determined that the current full current signal amplitude is less than or equal to the minimum endpoint value of the current measurement range required by the current measurement range, then the first switching operation is periodically performed on the measurement circuit that is currently conducting the relay until the current full current signal amplitude is within the current measurement range required by the current measurement range of the measurement circuit that is currently conducting the relay. The first switching operation includes disconnecting the currently active relay and connecting the relay at a lower current measurement level.

7. The method for monitoring electrical parameters of a surge arrester under operating load according to claim 5, characterized in that, The step of switching the conduction state of each measurement circuit of the multi-channel automatic switching acquisition circuit according to the current full current signal amplitude includes: If it is determined that the current full current signal amplitude is greater than or equal to the maximum endpoint value of the current measurement range required by the current measurement range, then the second switching operation is periodically performed on the measurement circuit that is currently conducting the relay until the current full current signal amplitude is within the current measurement range required by the current measurement range of the measurement circuit that is currently conducting the relay. The second switching operation includes disconnecting the currently active relay and connecting the relay of the next higher current measurement range.

8. The method for monitoring electrical parameters of a surge arrester under operating load according to claim 5, characterized in that, The electrical parameter monitoring results include resistive current waveforms; correspondingly, obtaining the electrical parameter monitoring results includes: The reference capacitor current waveform is obtained based on the reference capacitor current signal; The peak point of the reference capacitor current waveform is taken as the zero point of the resistive current waveform. Multiply the reference capacitor current by the ratio of the peak value of the actual capacitor current to the peak value of the reference capacitor current to obtain the adjusted reference capacitor current. Subtract the full current waveform from the adjusted reference capacitor current waveform to obtain the resistive current waveform.

9. The method for monitoring electrical parameters of a surge arrester under operating load according to claim 5, characterized in that, The electrical parameter monitoring results include resistive current waveforms; correspondingly, obtaining the electrical parameter monitoring results includes: When the harmonic content of the voltage waveform is less than 5% of the fundamental frequency, the voltage waveform is advanced by 90° to generate the current waveform to be processed. A coefficient is used to multiply the current waveform to be processed, and then the coefficient is dynamically adjusted so that the difference between the current waveform to be processed and the full current waveform at the peak of the voltage is 0, thus obtaining the resistive current waveform.

10. The method for monitoring electrical parameters of a surge arrester under operating load according to claim 5, characterized in that, The electrical parameter monitoring results include resistive current waveforms; correspondingly, obtaining the electrical parameter monitoring results includes: When the harmonic content of the voltage waveform is higher than 5% of the fundamental waveform, the voltage waveform is expanded into a Fourier series waveform to obtain several levels of voltage Fourier series waveforms; and the total current waveform is decomposed into a series and several levels of voltage Fourier series waveforms that correspond one-to-one with the current Fourier series waveforms. The Fourier series waveforms of each current are extracted according to the phase angle of the voltage waveform to obtain the extracted Fourier series waveforms of each current that are in phase with the voltage waveform. By superimposing the waveforms extracted from the Fourier series of each current, the resistive current waveform is obtained.

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