Partial discharge measurement system and its measuring device, partial discharge measurement method, and partial discharge measurement program

Abstract

To measure a partial discharge of a high-frequency drive high-voltage device without performing complex arithmetic processing.SOLUTION: A partial discharge measurement system 10 measures a stator coil 2, and comprises a coupling capacitor C, a detection impedance Z, an HPF 1, an HPF 2, an LPF, an oscilloscope 4, and a measuring device 6. A point sequence data file obtained by pairing an input voltage of the stator coil 2 or an output voltage through the HPF 1 or the HPF 2 with time information is inputted to a point sequence data file acquisition section of the measuring device 6. A noise deletion processing section regards an output voltage of the file as noise if it is within a range of a threshold and deletes it, but regards it as a PD voltage if the output voltage is outside the range of the threshold. A peak value takeout section compares positive and negative maximum values of the PD voltage and obtains the maximum absolute value. A graph drawing section draws the waveform of an input voltage with the waveform of the output voltage of the maximum absolute value along with the time information in a graph. A partial discharge energy estimation section estimates discharge energy of PD.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a technology for diagnosing insulation deterioration by detecting and measuring partial discharges (hereinafter referred to as PD) generated from high-voltage equipment such as rotating machines, inverters, and stationary equipment. [Background technology]

[0002] Conventional partial discharge measurement devices have been used to measure insulation deterioration in high-voltage equipment that is mainly powered by AC current at commercial frequencies (50Hz or 60Hz). However, in recent years, there has been an increase in device configurations that use inverters to adjust frequency and voltage for highly efficient operation.

[0003] For example, a method has been proposed in which a high voltage of 3 kV or more, a commercial frequency, is converted via an inverter to a frequency above the commercial frequency (60 Hz to several hundred Hz) to operate an electric motor. In this case, noise is generated due to the switching of the power semiconductors inside the inverter and their peripheral circuits, making it difficult to detect PD.

[0004] Patent Document 1 proposes a diagnostic device for such insulation deterioration due to PD, and Patent Document 2 proposes a device for removing noise from PD. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2016-223821 [Patent Document 2] Patent Publication No. 2020-076640 Summary of the Invention [Problem to be solved by the invention]

[0006] The devices of Patent Documents 1 and 2 have the following problems.

[0007] (1) The device in Patent Document 1 uses a current sensor to measure the current value when PD occurs via a coupling capacitor and records the measurement value. Based on the recorded measurement value, a phenomenon description model expressed in mathematical expressions and equivalent circuits within the device is determined. From this phenomenon description model, the probability of insulation degradation occurring and the degree of its progress are calculated, and the calculation results are presented to the user.

[0008] However, Patent Document 1 does not specify the power supply frequency to be diagnosed, and may not be suitable for rotating machines driven at high frequencies (for example, around 1 kHz).In addition, because it is specialized in PD (void discharge) caused by voids in the insulator, it may not be able to quantitatively evaluate PD caused by other causes (such as delamination and slot discharge).

[0009] (2) The partial discharge detector in Patent Document 2 identifies the source of PD generated in electrical equipment from the "φ-Q plot distribution" and attempts to remove PD noise. Specifically, it measures the waveform (= PD signal + noise superimposition) when PD is generated from sensors such as CT (current transformer), AE (acoustic emission detector), and TEV (electromagnetic transducer).

[0010] This measurement result is compared with the waveform of past noise accumulation data and statistically processed to extract only the noise-removed signal. The type of PD is then identified based on the data generated by machine learning and presented to the user.

[0011] However, as with Patent Document 1, the power supply frequency to be diagnosed is not specified, which may make it unsuitable for rotating machines driven at high frequencies (for example, around 1 kHz). Furthermore, noise processing is performed based on noise waveforms from past data and mixed waveforms containing noise and PD, resulting in complex calculations. Furthermore, identifying the type of PD by applying a machine-learned identification model requires even more complex calculations.

[0012] The present invention has been made to solve such conventional problems, and aims to achieve PD measurement of high-voltage equipment driven by high frequency without performing complex calculation processing. [Means for solving the problem]

[0013] (1) One aspect of the present invention is A partial discharge measurement system for measuring partial discharge of a measurement object, a circuit section for acquiring an input voltage and an output voltage of the measurement target; a measuring device for measuring partial discharge based on each voltage information acquired by the circuit unit; Equipped with The circuit unit includes a high-pass filter that removes a fundamental frequency signal of the output voltage to obtain a partial discharge signal; The measuring device is the input voltage of the measurement object and the output voltage that has passed through the high-pass filter are input from the circuit unit together with time information; a noise subtraction processing unit that removes noise within a predetermined threshold range from the waveform of the output voltage, and that determines voltages outside the threshold range as partial discharge voltages; a peak extraction processing unit that acquires the positive and negative maximum values ​​of the partial discharge voltage and compares the magnitudes of the acquired maximum values ​​to obtain a maximum absolute value; and a graph drawing unit that draws the waveform of the input voltage and the waveform of the output voltage with the maximum absolute value on a graph together with time information.

[0014] (2) Another aspect of the present invention is a circuit unit for acquiring an input voltage and an output voltage of an object to be measured; a measurement device for a partial discharge detection system, the measurement device including a high-pass filter in which the circuit unit removes a fundamental frequency signal of the output voltage to acquire a partial discharge signal, The input voltage of the measurement object and the output voltage that has passed through the high-pass filter are input together with time information; a noise subtraction processing unit that removes noise within a predetermined threshold range from the waveform of the output voltage, and that treats voltages outside the threshold range as partial discharge voltages; a peak extraction processing unit that acquires the positive and negative maximum values ​​of the partial discharge voltage and compares the magnitudes of the acquired maximum values ​​to obtain a maximum absolute value; and a graph drawing unit that draws the waveform of the input voltage and the waveform of the output voltage with the maximum absolute value on a graph together with time information.

[0015] (3) Yet another aspect of the present invention is a circuit section for acquiring an input voltage and an output voltage of the measurement target; a measuring device for measuring partial discharge based on each voltage information acquired by the circuit unit; Equipped with A method for performing a partial discharge measurement system including a high-pass filter in the circuit section, the high-pass filter removing a fundamental frequency signal of the output voltage to obtain a partial discharge signal, the method comprising: The measuring device acquiring the input voltage of the measurement target and the output voltage that has passed through the high-pass filter together with time information from the circuit unit; a step of removing a waveform of the output voltage within a predetermined threshold range as noise, and determining a waveform outside the threshold range as a partial discharge voltage; obtaining the maximum positive and negative values ​​of the partial discharge voltage and comparing the obtained maximum values ​​to obtain the maximum absolute value; and plotting the input voltage waveform and the maximum absolute value output voltage waveform together with time information on a graph.

[0016] (4) The present invention can be configured as a partial discharge measurement program that causes a computer to function as the measurement device. [Effects of the Invention]

[0017] According to the present invention, PD measurement of high-voltage equipment driven by high frequency can be performed without performing complex calculation processing. [Brief explanation of the drawings]

[0018] [Figure 1]1 is a diagram showing the overall configuration of a partial discharge measurement system according to an embodiment of the present invention; [Figure 2] 1A is a basic configuration diagram of the detection impedance, FIG. 1B is a configuration diagram of a first modified example thereof, and FIG. 1C is a configuration diagram of a second modified example thereof. [Figure 3] Functional block diagram of the measuring device [Figure 4] FIG. 2 is a flowchart showing the processing steps of the measuring device. [Figure 5] (a) is a schematic diagram of the point sequence data file of the output voltage, (b) is the output waveform diagram of the output voltage, and (c) is an enlarged view of one PD in (b). [Figure 6] (a) shows the noise subtraction process for the output waveform diagram in Fig. 5(a), and (b) is an enlarged view of one PD in (a). [Figure 7] (a) is a diagram of the situation where the maximum positive and negative values ​​of the peak value extraction process are determined from Fig. 6(b), (b) is a diagram of the situation where the maximum absolute value is determined from both maximum values ​​in (a), and (c) is the plotted graph. [Figure 8] Graph of discharge waveform pattern classification. [Figure 9] (a) is a graph showing PD due to delamination in the example, (b) is a graph showing PD due to internal voids in the example, (c) is a graph showing PD due to abnormalities in the electric field relaxation layer in the example, and (d) is a graph showing PD due to slot discharge in the example. [Figure 10] (a) Graph showing PD due to delamination in the comparative example, (b) graph showing PD due to internal voids in the comparative example, (c) graph showing PD due to abnormalities in the electric field relaxation layer in the comparative example, and (d) graph showing PD due to slot discharge in the comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0019] A partial discharge measurement system according to an embodiment of the present invention will be described below. This partial discharge measurement system measures the occurrence rate of PD and the magnitude of voltage by program processing of a measurement device (gauging device) configured by a computer, and further estimates the cause of PD and the discharge energy generated.

[0020] Here, we use a waveform processing program that can measure fundamental frequencies up to about 1 kHz without being affected by noise generated by the inverter. This makes it possible to handle input frequencies up to about 1 kHz, and we are attempting to measure PD for the high-frequency-driven rotating machines mentioned above.

[0021] 1 indicates an example of the configuration of the partial discharge measurement system 3. Here, the partial discharge measurement system 3 includes a circuit unit 7 that acquires the input voltage and output voltage of the stator coil 2, and a measurement device 6 that performs PD measurement based on the voltage values ​​acquired by the circuit unit 7.

[0022] The circuit unit 7 is connected to an AC power supply (high frequency, high voltage power supply) 1 via a stator coil 2. This stator coil 2 is a component of a rotating machine and constitutes the measurement target of the partial discharge measurement system 3. Although Fig. 1 shows the stator coil 2 of a rotating machine as an example of the measurement target, the measurement is not limited to this and can be performed on all types of high voltage equipment such as inverters and stationary equipment. Here, the explanation will be made by roughly dividing the circuit unit 7 and the measurement device 6.

[0023] ≪Circuit part 7≫ The circuit section 7 includes a high-voltage probe 5, a coupling capacitor C, a detection impedance Z, an LPF (low-pass filter), HPF1 and HPF2 (first high-pass filter, second high-pass filter), and an oscilloscope 4.

[0024] That is, the circuit unit 7 acquires an input voltage to the stator coil 2 to be measured via the high-voltage probe 5, and acquires an AC signal of the output voltage via the coupling capacitor C. The fundamental frequency of the acquired output voltage is removed by HPFs 1 and 2, and the PD output voltage is displayed on the oscilloscope 4.

[0025] Specifically, one end of the high-voltage probe 5 is connected to the stator coil 2 , the other end of the high-voltage probe 5 is connected to the oscilloscope 4 , and the input voltage of the stator coil 2 is input to the oscilloscope 4 .

[0026] One end of the coupling capacitor C is connected to the connection point between the stator coil 2 and the high-voltage probe 5, while the other end of the coupling capacitor C is connected to one end of the detection impedance Z, and the other end of the detection impedance Z is grounded.

[0027] The junction point between the coupling capacitor C and the detection impedance is connected to one end of the LPF and one end of HPF1, 2. The other end of the LPF and one end of HPF1, 2 are connected to an oscilloscope 4, and the output voltage of the stator coil 2 that has passed through the LPF and HPF1, 2 is input to the oscilloscope 4.

[0028] (1) Coupling capacitor To capture frequency components of the PD signal above the noise frequency band (approximately 40 MHz or less), it is preferable to select a vacuum capacitor with a capacitance (approximately 40 pF or less) whose cutoff frequency is at least twice the noise frequency band, i.e., 80 MHz or more, as the coupling capacitor C. However, a normal capacitor (with a capacitance of 100 pF or less due to power consumption considerations) may also be used as the coupling capacitor C.

[0029] (2) Detected Impedance The detection impedance Z will be explained based on Figure 2. This detection impedance Z is based on the configuration in Figure 2(a). Here, "In" indicates the connection to the low-voltage side of the coupling capacitor C, and "Out" indicates the connection from the "In" connection point to the LPF, HPF1 and 2, and oscilloscope 4.

[0030] Furthermore, "R" indicates a resistor, and "D" indicates a diode (either a "TVS diode" for preventing overvoltage application, a Zener diode, or a varistor). In the configuration of Figure 2(a), resistor R1 (for example, 2 kΩ) and diode D are connected in parallel.

[0031] However, there are many cases where it is necessary to consider the influence of the input impedance (50 Ω) of the LPF, HPF1, 2, and oscilloscope 4 connected to the "Out" side (output side). In such cases, the circuits shown in Figure 2(b) and (c) are used, which are combined so that the impedance seen from the "Out" side is approximately 50 Ω.

[0032] (3) LPF The LPF used has a cutoff frequency of 100 kHz or less to pass AC signals with a fundamental frequency of 50 Hz to 1 kHz. The high-voltage probe 5 is provided to correct the phase delay and voltage of the AC signal obtained through the LPF, and may be removed after the correction is complete.

[0033] (4)HPF1,2 HPF1 removes the AC signal of the fundamental frequency to obtain the PD signal. Specifically, to eliminate attenuation of the output pulse signal of the calibrator, which determines the relationship between the magnitude of the PD signal and the amount of discharge charge, a type with a cutoff frequency of several kHz to several tens of kHz is used. AC generally contains harmonics that affect PD signal processing, but it is necessary to remove at least the third-order harmonics (3 kHz for a frequency of 1 kHz) and the fifth-order harmonics (5 kHz for a frequency of 1 kHz). From this perspective, a cutoff frequency of 9 kHz is preferable for HPF1.

[0034] HPF2 removes noise caused by the fundamental frequency AC signal and inverter switching, etc., to obtain the PD signal. Here, it is preferable to use a type with a cutoff frequency of 50 MHz or higher for noise removal.

[0035] (5) Oscilloscope 4 Information about each input voltage is displayed on the oscilloscope 4. For example, the oscilloscope 4 used has the following specifications: Sample rate 2.5 GS / s (giga samples per second) = 2.5 x 10 9 per second (data interval: 0.4 nanoseconds) Frequency band Generally, the required frequency bandwidth of an oscilloscope is five times the highest frequency component contained in the measurement signal. Specifically, to capture a signal with a frequency bandwidth of 80 MHz, an oscilloscope with a frequency bandwidth of 450 MHz or more per channel is required. ·resolution If the resolution is 8 bits, it is 1 / 2 for a range of 1V. 8 =3.9mV. If the calibration signal is 1V (1000mV) = 1000pC, the resolution of the charge measurement value is 3.9pC. Input impedance LPF: If the input impedance is smaller than the resistance component of the detection impedance Z, it will not be possible to capture low frequency voltages, so it is preferable to set the input impedance to 1 MΩ.

[0036] HPF1, 2: To pass high frequency components, it is preferable that the input impedance is 50Ω.

[0037] <Measuring device 6> The measuring device 6 is connected via a LAN cable (not shown) to the oscilloscope 4 so as to be able to freely send and receive data. Specifically, the measuring device 6 is configured by a computer (such as a PC) and has the waveform processing program described above installed.

[0038] Here, as a result of cooperation between the computer's hardware resources (CPU, RAM, ROM, HDD, SSD, etc.) and software resources (OS, waveform processing program, etc.), the measuring device 6 is equipped with a point sequence data file acquisition unit 21, a noise subtraction processing unit 22, a peak value extraction unit 23, a graph drawing unit 24, and a partial discharge energy estimation unit 25, as shown in Fig. 3. The processing details (S01 to S05) of each of these units 21 to 25 will be explained with reference to Fig. 4.

[0039] S01: When the execution of the waveform processing program is started, the next point sequence data files (A) and (B) are automatically input from the oscilloscope 4 to the point sequence data file acquisition unit 21.

[0040] (A) A point sequence data file that stores pairs of character strings indicating the "time information; voltage value" of the input voltage of stator coil 2

[0041] (B) A point sequence data file containing pairs of character strings indicating the "time information; voltage value" of the output voltage of stator coil 2 through HPF1 or 2. Regarding the output voltage, it is preferable to switch between HPF1 and HPF2 as appropriate depending on the situation, for example, if a noise environment of the inverter is expected, input a point sequence data file (B) storing the output voltage of HPF2, and if that noise is not expected, input a point sequence data file (A) storing the output voltage of HPF1.

[0042] The number of inputs (acquisitions) of the point sequence data file can be specified as desired in the waveform processing program. However, as shown in Figure 5(a), from the viewpoint of accuracy stability, it is recommended to acquire the output voltage for one input voltage at least 50 times.

[0043] That is, for one cycle of the point sequence data file (A) acquired on the oscilloscope 4, "1 cycle x n (n≧50)" times of the point sequence data file (B) are input, and the processing from S02 onwards is executed on the input point sequence data files (A) (B) to be processed.

[0044] As a prerequisite, as shown in Figure 5(b) and (c), measurements have shown that when a PD occurs once, in addition to the PD pulse voltage represented by the rise and fall of one pulse, resonance and attenuation occur due to the impedance in the measurement circuit.

[0045] Furthermore, as a precondition 2, measurements have shown that the number of plots required from the occurrence of one PD until it converges due to resonance and attenuation is approximately 200 plots when the sampling rate of the oscilloscope 4 is 1 GS / s.

[0046] S02: The noise subtraction processor 22 acquires a group of point sequence data files (B) to be processed. One point sequence data file (B) is extracted from the acquired processing targets, and the following processing is performed on the output voltage waveform of the extracted point sequence data file (B).

[0047] That is, as shown in Figure 6(a), the voltage value is "±V noise If the voltage value is within the range, it is not considered to be PD but noise from the power supply, etc. On the other hand, if the voltage value is "±V noise If the value exceeds ", it is assumed that PD has occurred, and the voltage value is recorded as shown in Figure 6(b). This is called noise subtraction processing.

[0048] The threshold value is "±V noise The size of " is determined in advance according to the "VOLTS / DIV" setting (size of the vertical axis) of the oscilloscope 4, and this can be adjusted as appropriate depending on the situation, etc.

[0049] S03: The peak value extracting unit 23 determines whether the voltage value is "±V noise " and the time when the PD rises or falls is the starting point, 200 plots are obtained from the voltage record of S03 and the following processing is performed.

[0050] That is, as shown in Fig. 7(a), the acquired voltage values ​​are compared in time series, and the maximum positive value (V m1 ) and the negative maximum (V m2 ) and its time information are recorded. Then, as shown in Figure 7(b), the recorded maximum positive value (V m1 ) and the negative maximum (V m2 ) and the larger of the two (V m1 ) and identify each PD with a single voltage value. This is called peak value extraction processing. If multiple PDs occur in the point sequence data file (B), peak value extraction processing is performed for all PDs.

[0051] S04: The graph drawing unit 24 checks whether the noise subtraction process (S02) and the peak value extraction process (S03) have been completed for all of the input point sequence data files (B).

[0052] If the result of the check is that the processing has been completed, the process proceeds to S05, whereas if the processing has not been completed, the unprocessed point sequence data file is subjected to noise subtraction processing (S02) and peak value extraction processing (S03).

[0053] S05: The graph drawing unit 24 acquires the point sequence data file (A) to be processed and the output voltage values ​​recorded in S03, and executes the graph drawing shown in Fig. 7(c). That is, a waveform graph is created from the input voltage and time information stored in the point sequence data file (A) acquired in S01.

[0054] This graph has the input voltage value on the vertical axis and the time information on the horizontal axis (see Figure 9), and the output voltage values ​​recorded in S03 are superimposed at positions corresponding to the time information and plotted on a single graph. This graph makes it possible to determine the occurrence rate of PD and the magnitude of the PD voltage relative to the phase of the input voltage.

[0055] In addition, the cause (origin of PD occurrence) can be determined by comparing with a predetermined discharge waveform pattern distribution (classification). For example, the graph of discharge waveform pattern classification in "IEC / TS 60034-27-2" shown in Figure 8 is used for comparison. This graph shows the PD discharge voltage group against the phase of the input voltage, (1) Delamination on the wire side (2) Internal voids in the insulating layer (3) Abnormality in the electric field relaxation layer at the coil end (4) Coil slot discharge It is preferable to use a comparison of these patterns with the graph.

[0056] S06: The estimation unit 25 calculates the discharge energy generated by the PD using the formulas (1) to (3).

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[0060] <Measurement results of the example> An example of PD measurement using the partial discharge measurement system 3 will be described. In this example, the measurement target is a bar coil simulating the rotor end of a high-voltage rotating machine. A total of four types of coils with defects A to D are prepared, and each type is treated so that the PD in parentheses occurs. These coils are referred to as coils A to D, respectively. A: Coil with large separation between the main insulation layers (discharge due to separation between layers) B: Coil with small voids in the main insulation layer (discharge due to internal voids) C: Coil with a contaminated electric field buffer layer (discharge due to an abnormality in the electric field buffer layer) D: Coil in which part of the corona prevention layer has disappeared and there is a gap between the iron core slots (slot discharge) Then, a sine wave input of "8kVrms-1kHz" was applied to each of the coils, and point sequence data file (A) was obtained once for one cycle of the input voltage, and point sequence data file (B) was obtained 50 times for one cycle of the output voltage of HPF1.

[0061] Measurements were performed on each of these point sequence data files (A) and (B) after processing steps S02 to S06. In this measurement, a vacuum capacitor (24.06 pF) was used for the coupling capacitor C, the detection impedance Z was the type shown in Figure 2(a), and the HPF1 was a type with a cutoff frequency of 9 kHz.

[0062] Figures 9(a) to 9(d) show graphs of the respective measurement results. These graphs confirm that an output voltage is generated by the PD. Specifically, the graph in Figure 9(a) shows the measurement results for coil A, the graph in Figure 9(b) shows the measurement results for coil B, the graph in Figure 9(c) shows the measurement results for coil C, and the graph in Figure 9(d) shows the measurement results for coil D.

[0063] When comparing the graphs in Figures 9(a) to (d) with the graph of discharge waveform pattern classification in Figure 8, in Figure 9(a) a group of PD voltages appeared symmetrically with the positive and negative input voltages, confirming a phenomenon similar to the delamination in Figure 8.

[0064] In Figure 9(b), a group of PD voltages appeared when the input voltage switched from negative to positive, confirming a phenomenon similar to the internal voids in Figure 8. In Figure 9(c), a group of PD voltages appeared when the input voltage switched from positive to negative, confirming a phenomenon similar to the abnormality in the field relaxation layer in Figure 8.

[0065] In Fig. 9(d), a group of PD voltages appeared only on the positive side of the input voltage, confirming a phenomenon similar to the slot discharge in Fig. 8. As a result, it was found that PD measurement using the partial discharge measurement system 3 described above makes it possible to accurately classify the cause of PD occurrence by comparing and matching with the graph of discharge waveform pattern classification in Fig. 8.

[0066] <<Measurement results of comparative example>> Fig. 10 shows a graph of the measurement results of the comparative example. This graph shows the following for point sequence data files (A) and (B) of coils A to D, respectively: Noise reduction processing (S03) threshold "V noise Set the value of " as small as possible Peak value extraction process (S04) is not performed The measurement results are shown in the figure.

[0067] The graph in Figure 10(a) shows the measurement results for coil A, the graph in Figure 10(b) shows the measurement results for coil B, the graph in Figure 10(c) shows the measurement results for coil C, and the graph in Figure 10(d) shows the measurement results for coil D, each of which has the following defects.

[0068] (1) Because power supply noise and noise due to resonance and attenuation are also displayed, it is difficult to distinguish them from actual PD, making it difficult to identify the cause of PD.

[0069] (2) The number of unnecessary output voltage values ​​recorded increases, which increases the calculation process of the waveform processing program. In particular, when calculating the discharge energy in step S06, noise components are also calculated, making it difficult to accurately estimate the discharge energy.

[0070] This proves the superiority of the noise subtraction process (S03) and peak value extraction process (S04) performed by the measuring device 6. It is possible to measure partial discharges in high-frequency-driven high-voltage equipment without performing particularly complex calculations, and is effective for measuring PD for input voltage frequencies up to about 1 kHz, which is higher than the commercial frequency.

[0071] The present invention is not limited to the above-described embodiments, and can be modified and implemented within the scope of the claims. For example, the present invention can be configured as a waveform processing program (partial discharge measurement program) that causes a computer to function as the measurement device 6. This program makes it possible to cause the computer to execute the partial discharge measurement method processes S01 to S06. [Explanation of symbols]

[0072] C: Coupling capacitor HPF1,2...High-pass filters LPF: Low-pass filter Z: Detected impedance 1…AC power supply 2...Stator coil 4...Oscilloscope 5...Coupling capacitor 6...Measuring equipment 7...Circuit section 10. Partial discharge measurement system 21...Point sequence data file acquisition section 22...Noise subtraction processing section 23...Peak value extraction section 24...Graph drawing section 25...Partial discharge energy estimation section

Claims

1. A partial discharge measurement system for measuring partial discharge of a measurement object, a circuit unit for acquiring an input voltage and an output voltage of the measurement target; a measuring device for measuring partial discharge based on each voltage information acquired by the circuit unit; Equipped with The circuit unit includes a high-pass filter that removes a fundamental frequency signal of the output voltage to obtain a partial discharge signal; The measuring device is the input voltage of the measurement object and the output voltage that has passed through the high-pass filter are input from the circuit unit together with time information; a noise subtraction processing unit that removes noise within a predetermined threshold range from the waveform of the output voltage, and that determines voltages outside the threshold range as partial discharge voltages; a peak extraction processing unit that acquires the positive and negative maximum values ​​of the partial discharge voltage and compares the magnitudes of the acquired maximum values ​​to obtain a maximum absolute value; a graph drawing unit that draws a waveform of the input voltage and a waveform of the output voltage with the maximum absolute value on a graph together with time information; A partial discharge measurement system comprising:

2. a circuit unit for acquiring an input voltage and an output voltage of an object to be measured; a measurement device for a partial discharge measurement system, the measurement device including a high-pass filter in which the circuit unit removes a fundamental frequency signal of the output voltage to acquire a partial discharge signal, The input voltage of the measurement target and the output voltage that has passed through the high-pass filter are input together with time information; a noise subtraction processing unit that removes noise within a predetermined threshold range from the waveform of the output voltage, and that determines voltages outside the threshold range as partial discharge voltages; a peak extraction processing unit that acquires the positive and negative maximum values ​​of the partial discharge voltage and compares the magnitudes of the acquired maximum values ​​to obtain a maximum absolute value; a graph drawing unit that draws a waveform of the input voltage and a waveform of the output voltage with the maximum absolute value on a graph together with time information; A measuring device comprising:

3. The point sequence data file acquisition unit Obtain at least 50 output voltages for one input voltage, The graph drawing unit draws the graph by superimposing the output voltages of the maximum absolute values ​​on the waveform of the input voltage.

3. The measuring device according to claim 2.

4. The graph drawing unit The cause of partial discharge is estimated by comparing and matching the graph with a predetermined partial discharge pattern distribution.

4. The measuring device according to claim 2 or 3.

5. Converting the maximum absolute voltage value into a discharge charge amount per partial discharge, Calculating a current value corresponding to the discharge charge amount, a partial discharge energy estimation unit that estimates discharge energy generated by partial discharge by calculating Joule heat from the current value for the total number of partial discharges; 4. The measuring device according to claim 2, further comprising:

6. The partial discharge energy estimation unit 6. The measuring device according to claim 5, wherein the discharge energy of the partial discharge is estimated using the formulas (1) to (3). [Equation 1] Q ｊ = Charge V oｕｔ（ｊ） = Output voltage j = 1 to n K = constant [Equation 2] I = total partial discharge current [Equation 3] R t = Resistance value at the location where partial discharge occurs W = discharge energy

7. a circuit section for acquiring an input voltage and an output voltage of the measurement target; a measuring device for measuring partial discharge based on each voltage information acquired by the circuit unit; Equipped with A method for performing a partial discharge measurement system including a high-pass filter in the circuit section, the high-pass filter removing a fundamental frequency signal of the output voltage to obtain a partial discharge signal, the method comprising: The measuring device acquiring the input voltage of the measurement target and the output voltage that has passed through the high-pass filter together with time information from the circuit unit; a step of removing a waveform of the output voltage within a predetermined threshold range as noise, and determining a waveform outside the threshold range as a partial discharge voltage; obtaining the maximum positive and negative values ​​of the partial discharge voltage and comparing the obtained maximum values ​​to obtain the maximum absolute value; plotting the waveform of the input voltage and the waveform of the output voltage with the maximum absolute value on a graph together with time information; A partial discharge measuring method, comprising:

8. A partial discharge measurement program that causes a computer to function as the measurement device according to any one of claims 2 to 6.

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