JP6476204B2 - Partial discharge discrimination device and partial discharge discrimination method - Google Patents

Description

  The present invention relates to a partial discharge discrimination device and a partial discharge discrimination method.

  Conventionally, a method of evaluating the similarity of a measured signal to a partial discharge signal by a neural network (Neural network) and determining the presence or absence of the partial discharge is known (for example, Patent Document 1). .

JP-A-8-338856

  However, in the conventional method, since the parameters of the waveform signal are not compared, the partial discharge may not be accurately determined.

  Accordingly, an object of the present invention is to provide a partial discharge determination method and a partial discharge determination device that can accurately determine a partial discharge signal from an alternating current signal including noise and the like.

In one embodiment of the present invention, the partial discharge discriminating apparatus stores a data indicating the first characteristic of the first signal level of the first partial discharge with respect to time or frequency, and an alternating current is supplied to the power equipment. Using a measurement unit that measures a second signal level of the discharge generated by flowing and measures a second characteristic of the second signal level of the alternating current with respect to time or frequency, and a characteristic parameter based on the time or signal level, A determination unit that compares the first characteristic with the second characteristic to determine whether the discharge is the first partial discharge; and the characteristic parameter includes a first characteristic parameter and a second characteristic parameter A first probability value calculated based on similarity based on the first characteristic parameter based on the first characteristic parameter, and the second characteristic parameter. A probability value calculation unit for calculating a second probability value calculated based on similarity based on the probability that the discharge is the first partial discharge, and the second probability value for the first probability value. And a mapping unit for mapping the points of discharge .

  It is possible to provide a partial discharge determination device and a partial discharge determination method capable of accurately determining a partial discharge signal from an alternating current signal including noise and the like.

It is a system configuration figure explaining an example of a system configuration using a partial discharge discriminating device concerning one embodiment of the present invention. It is a block diagram explaining an example of the hardware constitutions of the partial discharge discrimination device which concerns on one Embodiment of this invention. It is a sequence diagram which shows an example of the whole process by the system using the partial discharge discrimination device which concerns on one Embodiment of this invention. It is a flowchart which shows an example of the whole process of each apparatus in the system using the partial discharge discrimination device which concerns on one Embodiment of this invention. It is a figure which shows an example of the signal waveform which shows the partial discharge which concerns on one Embodiment of this invention. It is a figure which shows an example of the characteristic parameter of the signal which concerns on one Embodiment of this invention. It is a figure which shows an example of the signal strength of the signal which shows the partial discharge which concerns on one Embodiment of this invention. It is a figure which shows an example of the characteristic parameter which concerns on the signal strength of the signal which concerns on one Embodiment of this invention. It is a figure which shows an example of the frequency component of the signal which shows the partial discharge which concerns on one Embodiment of this invention. It is a figure which shows an example of the characteristic parameter which concerns on the frequency component of the signal which concerns on one Embodiment of this invention. It is a figure which shows an example of the mapping of the 2nd signal based on the probability value which concerns on one Embodiment of this invention. It is a figure which shows an example of (phi) -QN distribution map concerning one Embodiment of this invention. 1 is a system configuration diagram illustrating an example of a system configuration in which a φ-QN measurement board is connected to a partial discharge determination device according to an embodiment of the present invention. It is a figure explaining an example of attenuation of partial discharge concerning one embodiment of the present invention. It is a system configuration figure explaining an example of the system configuration which inputs the 1st signal using the pulse generator concerning one embodiment of the present invention. It is a system configuration figure explaining an example of a system configuration which inputs a plurality of 1st signals using a pulse generator concerning one embodiment of the present invention. It is a figure which shows an example of the calculation result of the attenuation factor by the partial discharge discrimination device which concerns on one Embodiment of this invention. It is a figure which shows an example of the prediction method of the 1st signal of the partial discharge which generate | occur | produces in the arbitrary distance based on the attenuation factor by the partial discharge discrimination apparatus which concerns on one Embodiment of this invention. It is a figure which shows an example of the method of calculating the distance of the generation source of the partial discharge by the partial discharge discrimination device which concerns on one Embodiment of this invention. It is a functional block diagram which shows an example of a function structure of the partial discharge discrimination device which concerns on one Embodiment of this invention.

  Hereinafter, a partial discharge discriminating apparatus and a partial discharge discriminating method for discriminating partial discharge generated in the power equipment of the present invention will be described.

<Embodiment 1>
FIG. 1 is a system configuration diagram illustrating an example of a system configuration using a partial discharge determination device according to an embodiment of the present invention.

  The partial discharge measuring device 100 is an example of a measuring unit. Hereinafter, a case where the measurement unit is the partial discharge measurement device 100 will be described as an example. The partial discharge measuring apparatus 100 measures an alternating current including a partial discharge flowing through the power facility and noise. The power equipment is, for example, a cable, a connection box, and GIS (Gas Insulated Switch). In the following description, a case where the power equipment is a cable will be described as an example. The alternating current is an alternating current having a voltage exceeding 600V, for example. The partial discharge measuring device 100 is connected to the partial discharge determination device 101.

  The partial discharge measuring apparatus 100 includes a sensor 100H1, an amplifier 100H2, and a waveform measurement board 100H3.

  The sensor 100H1 is connected to a cable on which partial discharge is measured. Specifically, the sensor 100H1 has a high frequency measurement impedance, and the sensor 100H1 measures an alternating current flowing through the cable using the high frequency measurement impedance. Next, the sensor 100H1 converts the measured current value of the alternating current into a voltage value. Furthermore, the voltage value converted by the sensor 100H1 is output as a signal to the amplifier 100H2. The output terminal of the sensor 100H1 is connected to the input terminal of the amplifier 100H2.

  The amplifier 100H2 amplifies the signal output from the sensor 100H1. The output terminal of the amplifier 100H2 is connected to the input terminal of the waveform measurement board 100H3.

  The waveform measurement board 100H3 samples the signal amplified by the amplifier 100H2.

  The waveform measurement board 100H3 includes an A / D (Analog / Digital) converter (Converter) 100H31, a memory (Memory) 100H32, and an MCU (Micro Controller Unit) 100H33.

  The waveform measurement board 100H3 is an electronic circuit board on which an FPGA (Field-Programmable Gate Array) or the like is mounted.

  The A / D converter 100H31 has an input terminal of the waveform measurement board 100H3. The A / D converter 100H31 performs A / D conversion on the signal input from the amplifier 100H2. Note that the output terminal of the A / D converter 100H31 is connected to the input terminal of the memory 100H32 and the input terminal of the MCU 100H33.

  The memory 100H32 stores various data and various parameters used by the waveform measurement board 100H3.

  The MCU 100H33 has a microprocessor 100H331.

  The microprocessor 100H331 controls each hardware included in the waveform measurement board 100H3.

  The output terminal of the waveform measurement board 100H3 is connected to the input terminal of the partial discharge determination device 101.

  The waveform measurement board 100H3 outputs the sampled signal as data to the partial discharge determination device 101, and the partial discharge determination device 101 determines partial discharge from the output data and the like.

  In addition, the measurement of the alternating current including the partial discharge flowing through the power facility and noise is not limited to the measurement by the partial discharge measuring device 100. The alternating current may be measured by a measuring device other than the partial discharge measuring device 100. Moreover, the hardware configuration of the partial discharge measuring apparatus 100 may include an analysis device such as an oscilloscope and a spectrum analyzer.

<Hardware configuration example of partial discharge discrimination device>
FIG. 2 is a block diagram illustrating an example of a hardware configuration of the partial discharge determination device according to the embodiment of the present invention.

  The partial discharge discriminating apparatus 101 is, for example, a PC (Personal Computer).

  The partial discharge discriminating apparatus 101 has a CPU (Central Processing Unit) 101H1, a storage device 101H2, an input I / F (interface) 101H3, and an output I / F 101H4. The hardware included in the partial discharge determination apparatus 101 is connected to each other via a bus, and the hardware transmits and receives data and the like to each other.

  The CPU 101H1 is an arithmetic device and a control device that realize various processes performed by the partial discharge determination device 101 by reading a program or data from the storage device 101H2 and executing the processing.

  The storage device 101H2 is a main storage device such as a memory and an auxiliary storage device such as an HD (Hard Disk). The storage device 101H2 stores various programs, various parameters, and various data.

  The input I / F 101H3 is an interface for inputting various data and various parameters to the partial discharge determination device 101. A measuring device such as the partial discharge measuring device 100 is connected to the input I / F 101H3. The input I / F 101H3 may be a communication interface for inputting data and the like via a network. Furthermore, the input I / F 101H3 may have an interface to which an input device such as a keyboard is connected.

  The output I / F 101H4 is an interface that outputs data, processing results, and the like from the partial discharge determination device 101. Specifically, the output I / F 101H4 is an output device such as a display. The output I / F 101H4 may be a communication interface that outputs data or the like via a network or an external interface that outputs data or the like to a recording medium.

  The input I / F 101H3 and the output I / F 101H4 may be input / output devices such as a touch panel instead of the input device and the output device.

  Further, the hardware configuration of the partial discharge determination device 101 is not limited to the configuration shown in FIG. The partial discharge determination device 101 may have a configuration including hardware of the partial discharge measurement device 100 such as the sensor 100H1. Further, the partial discharge determination device 101 may be an information processing device such as a tablet or a server. In addition, the hardware configuration of the partial discharge determination device 101 may be, for example, a configuration further including a device for assisting each hardware included in the partial discharge determination device 101 inside or outside. Furthermore, the partial discharge determination device 101 does not have to be a single device. For example, the partial discharge determination apparatus 101 may be configured by two or more information processing apparatuses connected via a network or the like.

  That is, the partial discharge determination device 101 may be configured to perform processing in parallel, distributed, or redundantly with an external device that connects part or all of the processing performed by the partial discharge determination device 101 via a network or the like.

<Example of overall processing>
FIG. 3 is a sequence diagram showing an example of the overall processing by the system using the partial discharge discrimination device according to the embodiment of the present invention.

  The partial discharge discriminating apparatus 101 inputs a reference signal (hereinafter referred to as a first signal SIG1) for discriminating the partial discharge. In this case, the first signal SIG1 is a signal indicating partial discharge in an ideal state, for example. Further, the first signal SIG1 is input to the partial discharge discriminating apparatus 101, for example, as data indicating a voltage value for every predetermined time (step S01).

  The partial discharge measuring apparatus 100 measures an alternating current flowing through the power facility, and outputs a signal indicating the measured alternating voltage as a voltage value (hereinafter referred to as a second signal SIG2) to the partial discharge determining apparatus 101. In this case, similarly to the first signal SIG1, the second signal SIG2 is output to the partial discharge discriminating apparatus 101 by data indicating a voltage value for each predetermined time (step S02).

  The partial discharge discriminating apparatus 101 compares the first signal SIG1 with the second signal SIG2, and discriminates whether or not the second signal SIG2 is partial discharge (step S03).

  The overall processing is not limited to the processing order shown in FIG. For example, the process of step S03 may be performed in parallel with step S02, that is, during measurement of alternating current.

  FIG. 4 is a flowchart showing an example of overall processing of each device in the system using the partial discharge determination device according to the embodiment of the present invention.

  FIG. 4A is a flowchart showing an example of the entire process of the partial discharge measuring apparatus 100 in the system using the partial discharge determination apparatus according to the embodiment of the present invention.

  In step SA01, partial discharge measuring apparatus 100 measures alternating current.

  In step SA02, partial discharge measuring apparatus 100 outputs the measured alternating current as the second signal. Specifically, in step SA02, partial discharge measuring apparatus 100 outputs the alternating current measured in step SA01 to partial discharge discriminating apparatus 101 as a second signal. Note that the processing in step SA01 and step SA02 corresponds to the processing in step S02 in FIG.

  FIG. 4B is a flowchart showing an example of the entire process of the partial discharge determination device 101 in the system using the partial discharge determination device according to the embodiment of the present invention.

  In step SB01, the partial discharge determination device 101 receives the first signal. Note that the process of step SB01 corresponds to the process of step S01 of FIG.

  In step SB02, the partial discharge discrimination device 101 receives the second signal. Note that the process of step SB02 corresponds to the process of step S02 of FIG. Specifically, the process of step SB02 is a process of inputting second signal data output from the partial discharge measuring apparatus 100 in step SA02.

  In step SB03, the partial discharge determination device 101 compares the characteristic parameters of the first signal and the second signal to determine whether or not the second signal is a partial discharge. Note that the processing in step SB03 corresponds to the processing in step S03 in FIG.

<Example of partial discharge signal waveform>
FIG. 5 is a diagram illustrating an example of a signal waveform indicating partial discharge according to an embodiment of the present invention.

  The signal input to the partial discharge discriminating apparatus 101 as the first signal SIG1 in step S01 is, for example, the signal illustrated in FIG. The first characteristic is indicated by the first signal SIG1 shown in FIG. The first partial discharge is a discharge indicated by the first signal SIG1 or the like.

  In FIG. 5, the horizontal axis is an axis indicating time. In FIG. 5, the vertical axis represents the signal level with respect to time. Furthermore, in FIG. 5, the signal level is indicated by a voltage value. In addition, the first signal level is indicated by a vertical axis in FIG.

  The signal shown in FIG. 5 is an example of a signal indicating partial discharge. In this case, as shown in FIG. 5, the signal indicating the partial discharge is characterized by a rise time of about 10 to 20 nsec (nanoseconds) in the ideal state. The ideal state is, for example, a measurement environment without noise or the like, a state in which the measurement characteristics of the sensor are not reflected, or a measurement result based on a theoretical value obtained by calculation. The partial discharge discriminating apparatus 101 discriminates whether or not it is a partial discharge by comparing characteristic parameters indicating signal characteristics.

  The characteristic parameter is a parameter indicating a partial discharge characteristic depending on a signal voltage or a signal intensity. The signal level is a value indicating a signal strength, an output value, and the like, and is indicated by a voltage or a signal strength.

  The characteristic parameter is a value of a characteristic point of the signal such as the maximum value and the maximum value of the voltage. Specifically, the characteristic parameter is, for example, the maximum absolute value of the voltage. The characteristic parameter is searched, converted, or calculated from the data of the first signal SIG1. As the characteristic parameter, a value used for comparison may be input to the partial discharge determination device 101 as data.

  Further, the characteristic parameter is a value indicating a slope of a graph indicating a voltage, a degree of change of a signal such as a voltage change amount, and a change tendency. Specifically, the characteristic parameter is, for example, a voltage rising change amount or a voltage falling change amount.

  In addition, the characteristic parameter is a time required for a predetermined change in voltage. Specifically, the characteristic parameters include, for example, a voltage rise time, a voltage fall time, a time from the reference value BL to a reference value again, and a time from the reference value BL to the maximum value. It is a ratio with respect to the time from the change from the reference value BL to the reference value BL again.

  The reference value BL is, for example, a value of 0 V (volt) that is a ground potential, an initial value, or a value that is arbitrarily set by a user or the like. Hereinafter, the reference value BL is described with the same meaning.

  The characteristic parameter is a value indicating the characteristic of the signal in signal strength. Specifically, the characteristic parameter is, for example, a signal intensity per unit time.

  Furthermore, the characteristic parameter is a value indicating the characteristic of the signal in the frequency component. Specifically, the characteristic parameter is, for example, a signal intensity indicated for each frequency component.

  Note that the characteristic parameters are not limited to the values described above. The characteristic parameter may be a value indicating another characteristic of the signal.

  FIG. 6 is a diagram illustrating an example of a characteristic parameter of a signal according to an embodiment of the present invention.

  The characteristic parameter is, for example, a parameter shown in FIG. The characteristic parameters are not limited to the parameters shown in FIG. Each figure shown in FIG. 6 is a figure explaining a characteristic parameter, respectively. In step S03, the partial discharge discriminating apparatus 101 normalizes the time axis indicated by the horizontal axis and the voltage axis indicated by the vertical axis with respect to the waveform shape, and calculates a standard deviation at each time from the normalized graph. The partial discharge discriminating apparatus 101 performs pattern matching based on the calculated standard deviation, and calculates the similarity. The degree of similarity is calculated by inverting the positive and negative with the zero point of the AC signal as the boundary, taking into account the case where the polarity is reversed, and the larger one is adopted as the probability value. The probability value is expressed as a percentage. When the probability value is equal to or greater than a predetermined value, the partial discharge determination device 101 determines that the second signal SIG2 is partial discharge.

  FIG. 6A illustrates an example of a rise time characteristic parameter. The rise time is the time until the voltage value of the signal reaches the maximum value that is the peak of the waveform from the reference value BL. Note that the first time is, for example, a rise time.

  Specifically, the rise time is the time from the time T1 at which the voltage value starts to change from the reference value BL to the time T2 at which the voltage value reaches the maximum value.

  When the characteristic parameter is the rise time, in step S01, the partial discharge determination device 101 inputs the rise time value or calculates the rise time value from the input signal. Next, in step S03, the partial discharge determination device 101 compares the rise times to determine whether or not the second signal SIG2 is partial discharge.

  FIG. 6B is a diagram illustrating an example of the characteristic parameter of the rising change amount. In FIG. 6B, the rising change amount is indicated by an angle, an inclination, and the like formed by a line segment indicating the voltage value of the signal and a line segment indicating the reference value BL. The rising change amount is a change amount of the voltage value per unit time in the change from the reference value BL to the maximum value. The amount of change in voltage per unit time is, for example, a rising change amount.

  Specifically, the rising change amount is the change amount of the voltage value per unit time in the time from the time T1 when the voltage value starts to change from the reference value BL to the time T2 when the voltage value becomes the maximum value.

  When the characteristic parameter is the rising change amount, in step S01, the partial discharge determination device 101 inputs the rising change value or calculates the rising change value from the input signal. Next, in step S03, the partial discharge discriminating apparatus 101 compares the rising change amount and discriminates whether or not the second signal SIG2 is partial discharge.

  FIG. 6C is a diagram illustrating an example of the fall time characteristic parameter. The fall time is the time from the time T2 when the voltage value becomes the maximum value to the time T3 when the voltage value becomes the minimum value. Note that the second time is, for example, a fall time.

  When the characteristic parameter is the fall time, in step S01, the partial discharge determination device 101 calculates the fall time value from the input or input signal. Next, in step S03, the partial discharge determination device 101 compares the falling times to determine whether or not the second signal SIG2 is partial discharge.

  FIG. 6D is a diagram illustrating an example of the characteristic parameter of the falling change amount. In FIG. 6D, the falling change amount is indicated by an angle or inclination formed by a line segment indicating the voltage value of the signal and a line segment indicating the reference value BL. The falling change amount is a change amount of the voltage value per unit time in the change from the maximum value to the minimum value. Note that the amount of change in voltage per unit time is, for example, the amount of fall change.

  Specifically, the falling change amount is a change amount of the voltage value per unit time in the time from the time T2 when the voltage value becomes the maximum value to the time T3 when the voltage value becomes the minimum value.

  When the characteristic parameter is the falling change amount, in step S01, the partial discharge determination device 101 inputs the falling change amount value or calculates the falling change amount value from the input signal. Next, in step S03, the partial discharge discriminating apparatus 101 compares the falling change amount and discriminates whether or not the second signal SIG2 is a partial discharge.

  FIG. 6E is a diagram illustrating an example of a characteristic parameter having a maximum absolute value. FIG. 6E is a diagram illustrating the absolute values of the waveforms in FIGS. 6A to 6D. The maximum absolute value is the maximum voltage value that is the peak of the signal waveform. Note that the maximum absolute value is the voltage value at time T2 when the voltage value becomes the maximum value in FIG.

  When the characteristic parameter is the maximum value of the absolute value, in step S01, the partial discharge determination apparatus 101 inputs the value of the maximum value of the absolute value or searches for the value of the maximum value of the absolute value from the input signal. Next, in step S03, the partial discharge determination device 101 compares the absolute maximum values to determine whether or not the second signal SIG2 is partial discharge.

  FIG. 6F is a diagram illustrating an example of a characteristic parameter of time from the reference value BL until it becomes the reference value BL again. FIG. 6F is a diagram illustrating the absolute values of the waveforms in FIGS. 6A to 6D. The time from the change from the reference value BL to the reference value BL again is the waveform duration. Specifically, the time from the change from the reference value BL to the reference value BL again in FIG. 6F is the time when the voltage value starts again from the time T1 when the voltage value starts to change from the reference value BL. This is the time until the time T4 converges. Note that the third time is, for example, a time until the reference value BL changes again from the reference value BL.

  In the case where the characteristic parameter is a time until it changes from the reference value BL and becomes the reference value BL again, in step S01, the partial discharge determination device 101 changes the time from the reference value BL and becomes the reference value BL again. Is calculated from the input or input signal. Next, in step S03, the partial discharge determination device 101 compares the time from the reference value BL to the reference value BL again, and determines whether or not the second signal SIG2 is a partial discharge. .

  FIG. 6G illustrates an example of a characteristic parameter of the ratio between the time from the reference value BL to the maximum value and the time from the reference value BL to the reference value BL again. It is. FIG. 6G is a diagram illustrating absolute values of the waveforms in FIGS. 6A to 6D. The time from the reference value BL to the maximum value is the time A from the time T1 at which the voltage value starts to change from the reference value BL to the time T2 at which the voltage value reaches the maximum value. The time from the change from the reference value BL to the reference value BL again is the time B from the time T1 at which the voltage value starts changing from the reference value BL to the time T4 at which the voltage value converges again to the reference value BL. is there. Therefore, the ratio of the time from the reference value BL to the maximum value and the time from the reference value BL to the reference value BL again is A: B in FIG. 6 (G). The ratio between the first time and the third time is, for example, A: B in FIG.

  In the case where the characteristic parameter is the ratio of the time from the reference value BL to the maximum value and the time from the change from the reference value BL to the reference value BL again, in step S01, the partial discharge determination device 101 The ratio value is calculated from the input or input signal. Next, in step S03, the partial discharge determination device 101 compares the ratio between the time from the reference value BL to the maximum value and the time from the reference value BL to the reference value BL again. Then, it is determined whether or not the second signal SIG2 is partial discharge.

  The characteristic parameter may be a change in signal intensity per unit time calculated from the waveform shown in FIG.

  FIG. 7 is a diagram illustrating an example of signal strength of a signal indicating partial discharge according to an embodiment of the present invention.

  FIG. 7 is a diagram showing the signal strength of the signal shown in FIG. FIG. 7 differs from FIG. 5 in that the vertical axis indicates the signal intensity per unit time. As shown in FIG. 7, the partial discharge discriminating apparatus 101 obtains the time change of the signal intensity of the first signal input in step S01 and the pulse waveform value of the second signal SIG2 measured in step S02 in step S03. A comparison is made to determine whether the second signal SIG2 is a partial discharge.

  FIG. 8 is a diagram illustrating an example of a characteristic parameter related to signal strength of a signal according to an embodiment of the present invention.

  FIG. 8A and FIG. 8B are diagrams illustrating an example of the same second signal SIG2. Similarly, FIG. 8C and FIG. 8D are diagrams illustrating an example of the same second signal SIG2. 8A and 8C are diagrams in which the horizontal axis is a time axis and the vertical axis is a voltage value, as in FIG. 5, and FIGS. 8B and 8D are FIGS. It is a figure which makes a horizontal axis a time axis and makes a vertical axis | shaft the signal strength per unit time similarly to FIG. Since the signal strength of the second signal SIG2 is often not the same as the signal strength of the first signal, normalization processing may be performed on the measured second signal SIG2. The signal intensity per unit time may be an average value of the signal intensity per unit time.

  The second characteristic is indicated by the second signal SIG2 or the like. When the second signal SIG2 shown in FIG. 8 is measured, in step S03, the partial discharge determination device 101 compares the first signal SIG1 and the second signal SIG2 shown in FIG. It is determined whether or not the second signal SIG2 is partial discharge.

  For comparison of the characteristic parameter related to the signal intensity, the partial discharge discriminating apparatus 101 calculates the standard deviation at each time, for example, in the same manner as the characteristic parameter shown in FIG. In addition, the partial discharge discriminating apparatus 101 performs pattern matching based on the calculated standard deviation and calculates the similarity. In consideration of the case where the polarities are reversed, the degree of similarity is adopted as a probability value whichever of the positive or negative values has the larger absolute value. The comparison of the characteristic parameters related to the signal intensity is similar when the partial discharge discriminating apparatus 101 performs pattern matching using the graph of the first signal shown in FIG. 7 and the graph of the second signal SIG2 shown in FIG. The degree may be calculated. Similar to the characteristic parameter shown in FIG. 6, when the probability value is equal to or greater than a predetermined value, the partial discharge determination device 101 determines that the second signal SIG2 is partial discharge.

  In the second signal SIG2 shown in FIGS. 8A and 8B and the second signal SIG2 shown in FIGS. 8C and 8D, per unit time shown in FIG. 8B. The time change of the signal strength is similar to the time change of the signal strength per unit time shown in FIG. 7 as compared with the time change of the signal strength per unit time shown in FIG. The graph shown in FIG. 8B has two local maximum values, for example, like the graph shown in FIG. In addition, the graph illustrated in FIG. 8B has common features such as a curvature that is close to the graph illustrated in FIG. In contrast, the graph illustrated in FIG. 8D has fewer features in common with the graph illustrated in FIG. 7 than the graph illustrated in FIG. Therefore, the second signal SIG2 shown in FIGS. 8A and 8B is more similar to the first signal shown in FIG. 7 than the second signal SIG2 shown in FIGS. 8C and 8D. I can say that.

  As shown in FIGS. 5 and 8A, the second signal SIG2 may be measured with a voltage value having a polarity opposite to that of the first signal. In this case, when the partial discharge discriminating apparatus 101 discriminates the partial discharge based on the signal intensity per unit time, the partial discharge discriminating apparatus 101 shows the partial discharge without leaking the second signal SIG2 shown in FIG. It can be determined that it is a signal.

  The second signal SIG2 may have a certain difference in voltage value at each time, that is, a so-called offset with respect to the first signal. Even in this case, the signal intensity per unit time is the same value even when there is an offset. Therefore, when the partial discharge discriminating apparatus 101 discriminates partial discharge based on the signal intensity per unit time, the partial discharge discriminating apparatus 101 discriminates the second signal SIG2 having an offset with respect to the first signal as the partial discharge signal. be able to.

  Therefore, the partial discharge discriminating apparatus 101 discriminates the partial discharge based on the signal intensity per unit time, so that the partial discharge discriminating apparatus 101 can discriminate the partial discharge accurately even when there is an offset.

  The characteristic parameter may be a frequency component of a voltage value calculated from the waveform shown in FIG.

  FIG. 9 is a diagram illustrating an example of frequency components of a signal indicating partial discharge according to an embodiment of the present invention.

  FIG. 9 is a diagram showing frequency components of the signal shown in FIG. FIG. 9 is a diagram in which the vertical axis indicates signal intensity and the horizontal axis indicates frequency. As shown in FIG. 9, the partial discharge discrimination device 101 compares the frequency component of the first signal input in step S01 and the frequency component of the second signal SIG2 measured in step S02 in step S03, It is determined whether or not the signal SIG2 is partial discharge. The partial discharge discriminating apparatus 101 performs frequency analysis, and the frequency component is indicated by the frequency distribution obtained by the frequency analysis. In the frequency analysis, frequency conversion such as FFT (Fast Fourier Transform) or wavelet conversion is performed. As in FIG. 8 and the like, normalization processing may be performed on the measured second signal SIG2. That is, FIG. 9 is an example of an analysis result obtained by performing frequency analysis such as FFT on the signal shown in FIG.

  FIG. 10 is a diagram illustrating an example of a characteristic parameter related to a frequency component of a signal according to an embodiment of the present invention.

  FIG. 10A and FIG. 8A are diagrams illustrating an example of the same second signal SIG2. FIG. 10A is an example of a diagram illustrating the second signal SIG2 illustrated in FIG. Similarly, FIGS. 10B and 8C are diagrams illustrating an example of the same second signal SIG2. FIG. 10B is an example of a diagram illustrating the second signal SIG2 illustrated in FIG.

  The graph shown in FIG. 10A has more frequency components and is distributed in a lower frequency band than, for example, FIG. 10B. Similarly, the graph shown in FIG. 9 includes many frequency components and is distributed in a low frequency band. Therefore, it can be said that the second signal SIG2 illustrated in FIG. 10A is more similar to the first signal SIG1 illustrated in FIG. 9 than the second signal SIG2 illustrated in FIG.

  The signal magnitude of the second signal SIG2 may be significantly different from that of the first signal SIG1. Even in this case, the frequency components have the same distribution even when the signal sizes differ greatly. Therefore, when partial discharge discriminating apparatus 101 discriminates partial discharge based on the frequency component, partial discharge discriminating apparatus 101 can discriminate second signal SIG2 having an offset with respect to first signal SIG1 as a partial discharge signal. .

  The second signal SIG2 may have an offset with respect to the first signal SIG1. The frequency component has the same value even when there is an offset. Therefore, when partial discharge discriminating apparatus 101 discriminates partial discharge based on the frequency component, partial discharge discriminating apparatus 101 can discriminate second signal SIG2 having an offset with respect to first signal SIG1 as a partial discharge signal. .

  Therefore, the partial discharge discriminating apparatus 101 discriminates the partial discharge based on the frequency component, so that the partial discharge discriminating apparatus 101 can discriminate the partial discharge accurately even when there is an offset.

  Note that the partial discharge determination device 101 may determine the second signal SIG2 using two or more characteristic parameters among the characteristic parameters shown in FIGS.

  For example, the partial discharge discriminating apparatus 101 discriminates the second signal SIG2 by using the signal strength characteristic parameter per unit time shown in FIG. 7 and the like and the frequency component characteristic parameter shown in FIG. In this case, the partial discharge discriminating apparatus 101 can discriminate the partial discharge with higher accuracy than discrimination using any one of the characteristic parameters.

  For example, the partial discharge discriminating apparatus 101 discriminates the second signal SIG2 using the rise time shown in FIG. 6A and the rise change amount characteristic parameter shown in FIG. Both the rise time and rise change amount characteristic parameters can be calculated with data up to the maximum value. Therefore, when the partial discharge discriminating apparatus 101 discriminates based on the characteristic parameters of the rise time and the rise change amount, it can discriminate the partial discharge with a small amount of data with high accuracy.

  For example, the partial discharge discriminating apparatus 101 discriminates each of the second signals SIG2 using the rise time shown in FIG. 6A and the maximum absolute characteristic parameter shown in FIG. In this case, the characteristic parameter of the rise time and the maximum value of the absolute value can be calculated with a small calculation cost. Therefore, when the partial discharge discriminating apparatus 101 discriminates based on the characteristic parameter of the rise time and the maximum value of the absolute value, the partial discharge discriminating apparatus 101 can discriminate the partial discharge accurately with a small calculation cost.

  For example, the partial discharge discriminating apparatus 101 discriminates the second signal SIG2 using the rising change amount shown in FIG. 6B and the maximum absolute characteristic parameter shown in FIG. In this case, the characteristic parameter of the rising change amount and the maximum absolute value can be calculated with little error even when the signal size is different. Therefore, the partial discharge discriminating apparatus 101 can discriminate the partial discharge with high accuracy even when discriminating based on the characteristic parameter of the rising change amount and the maximum value of the absolute value, even when the signal size is different.

  When two or more characteristic parameters are used, for example, the partial discharge determination device 101 calculates an average value from the probability values of each characteristic parameter, and performs determination based on the average value.

  Further, when two or more characteristic parameters are used, for example, the partial discharge determination device 101 determines the second signal SIG2 by each characteristic parameter, and the logical sum (OR), logical product (AND), and Discrimination is performed by arbitrarily combining exclusive ORs (XOR).

  When determining by logical sum, if it is determined that partial discharge is determined based on at least one of the two or more characteristic parameters, the partial discharge determination device 101 determines that the second signal is obtained in step S03. It is determined that SIG2 is a partial discharge. Therefore, when discriminating by logical sum, the probability of overlooking the case where the second signal SIG2 is a partial signal can be reduced compared to the case of discriminating by one characteristic parameter, and the partial discharge discriminating apparatus 101 can be accurately used. Partial discharge can be determined.

  When discriminating by logical product, if it is discriminated that all of the two or more characteristic parameters are partial discharges based on the discrimination based on each characteristic parameter, the partial discharge discriminating apparatus 101 determines that the second signal SIG2 is a partial signal in step S03. It is determined that it is a discharge. Therefore, when discriminating by logical product, the probability that the second signal SIG2 is a partial signal can be increased as compared with the case of discriminating by one characteristic parameter, and the partial discharge discriminating apparatus 101 can accurately perform partial discharge. Can be determined.

  When discriminating by exclusive OR, when different discrimination is made based on each of the two or more characteristic parameters, the partial discharge discriminating apparatus 101 determines that the second signal SIG2 is partial discharge in step S03. Determine that there is. Therefore, when discriminating by exclusive OR, compared with the case of discriminating by one characteristic parameter, it is possible to reduce the probability of overlooking the case where the second signal SIG2 is a partial signal. Partial discharge can be determined with high accuracy.

  When the partial discharge discriminating apparatus 101 uses two characteristic parameters for discrimination, the partial discharge discriminating apparatus 101 may map a probability value calculated based on each characteristic parameter.

  FIG. 11 is a diagram illustrating an example of mapping of the second signal SIG2 based on the probability value according to the embodiment of the present invention.

  Hereinafter, the case where the partial discharge discriminating apparatus 101 uses two characteristic parameters of the signal intensity per unit time shown in FIG. 7 and the like and the frequency component shown in FIG. 9 and the like will be described as an example. In FIG. 11, the vertical axis represents the probability value based on the frequency component characteristic parameter, and the horizontal axis represents the probability value based on the signal strength characteristic parameter per unit time. That is, FIG. 11 is a diagram illustrating an example in which the first characteristic parameter is a characteristic parameter of signal strength per unit time and the second characteristic parameter is a frequency component characteristic parameter.

  FIG. 11 is an example in which the horizontal axis indicates the first probability value and the vertical axis indicates the second probability value. Note that the mapping by the partial discharge discriminating apparatus 101 is not limited to the horizontal axis and the vertical axis shown in FIG. For example, the first probability value and the second probability value may be probability values based on characteristic parameters other than the characteristic parameters shown in FIG.

  When the partial discharge discriminating apparatus 101 measures a plurality of second signals SIG2, the partial discharge discriminating apparatus 101 determines a probability value for each second signal SIG2 based on two characteristic parameters of signal intensity and frequency component per unit time. Calculate Next, the partial discharge discriminating apparatus 101 maps each second signal SIG2 as a point to the coordinates corresponding to the calculated probability value.

  When the partial discharge discriminating apparatus 101 maps a plurality of second signals SIG2, the second signal SIG2 has the same value for each characteristic parameter, and the distribution is biased. For example, as illustrated in FIG. 11, the second signal SIG2 may have two concentrated distributions. Here, in FIG. 11, a group including all the second signals SIG2 in the entire range, that is, the second signals SIG2 to be measured is defined as a first group G1. In FIG. 11, among the second signals SIG2 included in the first group G1, one group of the second signals SIG2 is defined as a second group G2. Furthermore, in FIG. 11, among the second signals SIG2 included in the first group G1, a group of the second signals SIG2 different from the second group G2 is defined as a third group G3.

  In step S03, partial discharge discriminating apparatus 101 determines that there is a possibility of partial discharge, for example, if the probability value is 60% or more and less than 70%, and if the probability value is 70% or more and less than 80%, the partial discharge has a high probability. If it is a discharge and the probability value is 80% or more, it is determined as a partial discharge. Each value may be changed by setting depending on the input method of the first signal SIG1.

  Next, in step S03, the partial discharge discrimination device 101 generates distribution data based on the mapped distribution. The distribution data is, for example, data represented by a φ-QN distribution diagram.

  FIG. 12 is a diagram illustrating an example of a φ-QN distribution diagram according to an embodiment of the present invention.

  In FIG. 12, the horizontal axis is an axis indicating the phase φ of the AC current flowing through the power equipment indicated by the second signal SIG2, and the vertical axis is obtained by the phase φ of the AC current flowing through the power equipment indicated by the horizontal axis. It is an axis indicating charge. The charge is indicated by a charge amount Q. Further, in FIG. 12, the color of each point indicates the frequency N of occurrence of each charge obtained at the phase φ per unit time. The generation frequency N is obtained by integrating the cases where charges having the same phase φ and the same charge amount Q are generated per unit time.

  FIG. 12A is a diagram illustrating an example of a φ-QN distribution diagram of the first group G1 according to an embodiment of the present invention.

  FIG. 12A includes φ-QN distribution diagrams of the second group G2 and the third group G3.

  FIG. 12B is a diagram illustrating an example of a φ-QN distribution diagram of the second group G2 according to an embodiment of the present invention.

  FIG. 12C is a diagram illustrating an example of a φ-QN distribution diagram of the third group G3 according to an embodiment of the present invention.

  As shown in FIGS. 12B and 12C, the second group G2 and the third group G3 differ in the phase φ of the alternating current and the charge amount Q indicated by the signals included in each group, It can be seen that the alternating current has different properties. Therefore, the detailed analysis of the second signal SIG2 can be performed by generating the φ-QN distribution map.

  In addition, distribution data is not restricted to the structure which the partial discharge discrimination device 101 produces | generates.

  FIG. 13 is a system configuration diagram illustrating an example of a system configuration in which a φ-QN measurement board is connected to the partial discharge determination device according to an embodiment of the present invention.

  The φ-QN measurement board 104 includes an A / D converter 104H1, a memory 104H2, and an MCU 104H3.

  The φ-QN measurement board 104 is an electronic circuit board on which an FPGA or the like is mounted.

  The φ-QN measurement board 104 generates distribution data based on the second signal SIG2. The φ-QN measurement board 104 calculates a peak point, which is a local maximum point of each waveform included in the second signal SIG2, by digital filter processing. At this time, the φ-QN measurement board 104 calculates the phase φ at the peak point in the φ-QN measurement by using the phase reference point and the internal counter of the microprocessor 104H31.

  The memory 104H2 stores various data and various parameters used by the φ-QN measurement board 104. An output terminal included in the memory 104H2 is connected to an input terminal included in the MCU 104H3.

  The MCU 104H3 has a microprocessor 104H31.

  The microprocessor 104H31 controls each hardware included in the φ-QN measurement board 104.

  The input / output terminals included in the φ-QN measurement board 104 are connected to the input / output terminals included in the partial discharge determination device 101.

  The φ-QN measuring board 104 outputs the distribution data generated to the partial discharge discriminating apparatus 101, and the partial discharge discriminating apparatus 101 displays the distribution data in a φ-QN distribution diagram or the like.

  The detection processing circuit 105 performs detection processing. In the detection process, the presence or absence of each waveform included in the second signal SIG2 is detected. The output terminal of the detection processing circuit 105 is connected to the input terminal of the φ-QN measurement board 104. Further, the input terminal of the detection processing circuit 105 is connected to the output terminal of the filter 106.

  Note that the charge amount Q detected by the φ-QN measurement board 104 may be obtained by performing digital filter processing on the signal waveform sampled by the partial discharge measurement device 100.

  The filter 106 is a band-pass filter. The filter 106 extracts a signal in a specific frequency band from the second signal SIG2 amplified by the amplifier 100H2. Note that the input terminal of the filter 106 is connected to the output terminal of the amplifier 100H2.

  The phase detection sensor 107 is attached to a power facility such as a cable. The phase detection sensor 107 detects a high-voltage current or voltage flowing through the power equipment. The output terminal of the phase detection sensor 107 is connected to the input terminal of the phase signal processing circuit 108.

  The phase signal processing circuit 108 detects a zero-cross of the signal input from the phase detection sensor 107. Next, the phase signal processing circuit 108 outputs the reference point to the φ-QN measurement board 104 and the partial discharge measurement device 100 based on the detected zero cross. Note that the output terminal of the phase signal processing circuit 108 is connected to the input terminal of the φ-QN measurement board 104 and the input terminal of the partial discharge measurement device 100.

  The partial discharge discriminating apparatus 101 can accurately discriminate the partial discharge by mapping the second signal SIG2 based on the probability value calculated based on each characteristic parameter. Furthermore, the partial discharge determination apparatus 101 can perform detailed analysis of the second signal SIG2 by grouping the second signal SIG2 by mapping and generating a φ-QN distribution map.

  Note that the partial discharge determination device 101 is not limited to performing determination using two characteristic parameters. Specifically, the partial discharge determination apparatus 101 may perform determination using three or more characteristic parameters.

<Embodiment 2>
When a partial discharge occurs in a power facility such as a cable, the partial discharge is attenuated by a propagation characteristic of the cable through which the partial discharge flows and a joint installed on a path through which the partial discharge flows.

  FIG. 14 is a diagram for explaining an example of attenuation of partial discharge according to an embodiment of the present invention.

  FIG. 14A is a diagram for explaining the distance between the occurrence location of the partial discharge according to the embodiment of the present invention and the measurement location of the second signal SIG2 by the partial discharge measuring apparatus 100 according to the embodiment of the present invention. It is.

  For example, in FIG. 14, a location where the second signal SIG2 is measured by the partial discharge measuring device 100 is set as a measurement point P0. That is, the distance of the measurement point P0 is “0”. Furthermore, as illustrated in FIG. 14A, it is assumed that there are a point P1 and a point P2 that are different in distance from the measurement point P0, and the point P2 is a point far from the measurement point P0 that is longer than the point P1. Hereinafter, three points shown in FIG. 14A will be described as an example. FIG. 14 illustrates an example in which the same partial signal is generated at three points, and all the generated partial signals are measured by the partial discharge measuring device 100 at the measurement point P0.

  In FIG. 14, the second signal level of the discharge generated by the alternating current flowing through the power facility is measured at the second point, which is the measurement point P0. In FIG. 14, the first partial discharge is a partial discharge generated at the points P1 and P2.

  FIGS. 14B and 14C are diagrams illustrating an example of the second signal SIG2 measured at the measurement point P0 by the partial discharge measurement device 100 according to an embodiment of the present invention. Specifically, FIG. 14B is a diagram showing the second signal SIG2 with the horizontal axis as a time axis and the vertical axis as a voltage axis, as in FIG. FIG. 14C is a diagram showing the second signal SIG2 with the horizontal axis as the frequency axis and the vertical axis as the signal intensity axis, as in FIG. FIG. 14C shows the analysis result obtained by frequency analysis of the second signal SIG2 shown in FIG.

  Since the second signal SIG2 measured at the measurement point P0 is less attenuated, the waveform is steep and many high-frequency components are measured.

  FIGS. 14D and 14E are diagrams for explaining an example of the second signal SIG2 measured at the point P1 by the partial discharge measuring apparatus 100 according to an embodiment of the present invention. Specifically, FIG. 14D is a diagram showing the second signal SIG2 with the horizontal axis as the time axis and the vertical axis as the voltage axis, as in FIG. 14B. FIG. 14E is a diagram showing the second signal SIG2 with the horizontal axis as the frequency axis and the vertical axis as the signal intensity axis, as in FIG. 14C. FIG. 14E shows the result of frequency analysis of the second signal SIG2 shown in FIG.

  FIGS. 14F and 14G are diagrams illustrating an example of the second signal SIG2 measured at the point P2 by the partial discharge measurement device 100 according to an embodiment of the present invention. Specifically, FIG. 14 (F) is a diagram illustrating the second signal SIG2 with the horizontal axis as a time axis and the vertical axis as a voltage axis, as in FIG. 14 (B). FIG. 14G is a diagram showing the second signal SIG2 with the horizontal axis as the frequency axis and the vertical axis as the signal intensity axis, as in FIG. 14C. FIG. 14G shows the result of frequency analysis of the second signal SIG2 shown in FIG.

  As illustrated in each drawing of FIG. 14, the second signal SIG2 attenuates with distance, and the attenuation becomes more significant as the distance becomes longer. Therefore, as illustrated in FIG. 14F, the attenuated second signal SIG2 has a duller waveform due to attenuation than the second signal SIG2 illustrated in FIGS. 14B and 14D. Further, as illustrated in FIG. 14G, the attenuated second signal SIG2 has a signal strength of each frequency component due to attenuation, as compared with the second signal SIG2 illustrated in FIGS. 14C and 14E. descend. In particular, the high-frequency component is more significantly attenuated by the distance than the low-frequency component.

  FIG. 15 is a system configuration diagram illustrating an example of a system configuration for inputting the first signal using the pulse generator according to the embodiment of the present invention.

  The configuration shown in FIG. 15 is different from the configuration shown in FIG. 1 in that the sensor 100H1 is connected to a power facility to which a pulse generator 103 is connected. In an environment where foil-like electrodes are used, when driven, the pulse generator 103 performs indirect injection in which pulses are injected from an injection electrode provided next to the detection electrode. Alternatively, when the pulse generator 103 is driven, it directly injects a pulse between the high-voltage part and the ground part. In this case, the pulse injected by the pulse generator 103 is a signal corresponding to partial discharge. That is, the pulse generator 103 generates a pulse that simulates partial discharge. The first point is a point where, for example, an electrode for injection is provided.

  Further, the pulse injection is not limited to a method in which a foil-like electrode is used. For example, a method in which a pulse is injected between a conductor and ground or a method in which a pulse is injected by coupling of a capacitor. Etc.

  The partial discharge discriminating apparatus 101 inputs a pulse generated by the pulse generator 103 as the first signal SIG1. In this case, since the pulse generated by the pulse generator 103 is input to the partial discharge discriminating apparatus 101 through the power equipment, the connection method of the sensor 100H1, the structure of the power equipment to be measured, the length of the ground wire, etc. Affected by. Therefore, when the pulse generated by the pulse generator 103 is input as the first signal SIG1, the characteristics of the power equipment, the signal detection characteristics of the sensor 100H1, and the like are reflected in the first signal SIG1. Therefore, the partial discharge discriminating apparatus 101 can discriminate the second signal SIG2 more accurately when the pulse generated by the pulse generator 103 is input as the first signal SIG1 than the ideal first signal SIG1. .

  The first signal SIG1 may be a voltage value characteristic measured by the partial discharge measuring device 100 or the like. That is, for example, a signal that is considered to be a partial discharge signal among signals measured by the partial discharge measurement device 100 may be selected and stored as the first signal SIG1 by the partial discharge determination device 101. In this case, compared to the first signal SIG1 in the ideal state, the partial discharge determination device 101 uses the second signal SIG2 because the first signal SIG1 reflecting the characteristics of the power equipment and the signal detection characteristics of the sensor 100H1 is used. Can be determined accurately.

  Note that the pulse generator 103 may be connected at different points and inject pulses at each point, and the partial discharge determination device 101 may store a plurality of first signals SIG1.

  FIG. 16 is a system configuration diagram illustrating an example of a system configuration that inputs a plurality of first signals using a pulse generator according to an embodiment of the present invention.

  FIG. 16 is a diagram illustrating the same three points as in FIG. Specifically, as illustrated in FIG. 16, the pulse generator 103 is connected to, for example, the measurement point P0, the point P1, and the point P2. In this case, the sensor 100H1 measures the pulse injected by the pulse generator 103 at the measurement point P0, the point P1, and the point P2 at the measurement point P0. In FIG. 16, the measurement point P0 is the second point, and the points P1 and P2 are the first points.

  The partial discharge discriminating apparatus 101 stores the pulse injected at the measurement point P0 as the first signal SIG1. Similarly, the partial discharge discriminating apparatus 101 stores the pulses injected at the points P1 and P2 as the first signal SIG1. The first signal SIG1 due to the pulses injected at each point reflects the characteristics of the power equipment, the signal detection characteristics of the sensor 100H1, and the like, and also reflects the attenuation due to the distance shown in FIG. That is, the first signal SIG1 due to the pulse injected at the point P1 is a signal shown in FIGS. 14D and 14E than the first signal SIG1 in the ideal state than the first signal SIG1 in the ideal state. The signal is similar to. Similarly, the first signal SIG1 due to the pulse injected at the point P2 is shown in FIGS. 14F and 14G than the first signal SIG1 in the ideal state, compared to the first signal SIG1 in the ideal state. The signal is similar to the signal.

  In step S03, the partial discharge determination device 101 compares each of the plurality of first signals SIG1 storing the second signal SIG2, and determines whether or not the second signal SIG2 is partial discharge. In this case, since each of the plurality of first signals SIG1 reflects attenuation due to distance or the like, even if the second signal SIG2 is attenuated, the partial discharge determination device 101 can determine that it is partial discharge. .

  Therefore, the partial discharge discriminating apparatus 101 accurately discriminates whether or not the second signal SIG2 generated at the point P1, the point P2, etc. is a partial discharge by storing a plurality of first signals SIG1 at points having different distances. Can do.

  The partial discharge discriminating apparatus 101 may calculate an attenuation rate. The pulse generator 103 cannot always inject pulses from a long distance depending on the situation.

  FIG. 17 is a diagram illustrating an example of a calculation result of the attenuation rate by the partial discharge determination device according to the embodiment of the present invention.

  The partial discharge discriminating apparatus 101 calculates an attenuation rate DAR with respect to distance for each frequency, for example. As shown in FIG. 17, the vertical axis indicates the attenuation results due to the distance for each frequency indicated by the horizontal axis.

  The partial discharge discriminating apparatus 101 predicts a first signal SIG1 of partial discharge generated at an arbitrary distance, for example, based on the first signal SIG1 measured at the measurement point P0.

  FIG. 18 is a diagram illustrating an example of a method for predicting the first signal of partial discharge generated at an arbitrary distance based on the attenuation rate by the partial discharge determination device according to the embodiment of the present invention.

  In FIG. 18, the partial discharge discriminating apparatus 101 inputs partial discharge signal data DP0 of the first signal SIG1 measured at the measurement point P0. In this case, the partial discharge signal data DP0 is data indicating a waveform similar to the waveform shown in FIG. The partial discharge discriminating apparatus 101 predicts a first signal SIG1 of partial discharge generated at a point PN at an arbitrary distance.

  As illustrated in FIG. 18, the partial discharge determination device 101 specifies the attenuation rate DAR corresponding to the distance of the point PN that is an arbitrary distance. Next, the partial discharge discriminating apparatus 101 attenuates the frequency components of the waveform indicated by the partial discharge signal data based on the attenuation rate DAR, and generates the measurement data DPN of the point PN at an arbitrary distance. The measurement data DPN at the point PN at an arbitrary distance is a signal (hereinafter referred to as a third signal SIG3) indicating a partial discharge generated at the point PN at an arbitrary distance.

  The partial discharge discriminating apparatus 101 obtains the frequency distribution of the waveform indicated by the partial discharge signal data by frequency conversion using wavelet transform or the like. Next, the partial discharge discriminating apparatus 101 attenuates each frequency based on the attenuation factor DAR, and generates the third signal SIG3 by inverse transformation of wavelet transformation or the like. Furthermore, the partial discharge discriminating apparatus 101 stores the measurement data DPN of the point PN that is an arbitrary distance to be generated as the third signal SIG3. In this case, the second partial discharge is indicated by the third signal SIG3 or the like. The third characteristic is indicated by a third signal level that is, for example, a voltage value of the third signal SIG3.

  The embodiment is not limited to the case where the partial discharge determination device 101 generates the third signal SIG3. The partial discharge discriminating apparatus 101 may perform correction for attenuating each frequency based on the attenuation rate DAR. For example, as shown in FIG. 9, when the partial discharge discriminating apparatus 101 performs frequency analysis, the partial discharge discriminating apparatus 101 attenuates each frequency based on the attenuation rate DAR based on the result of the frequency analysis, and calculates the predicted frequency distribution. calculate. In this case, the partial discharge determination device 101 may determine the second signal SIG2 based on the calculated frequency distribution.

  The partial discharge discriminating apparatus 101 calculates an attenuation rate with respect to the distance. Next, the partial discharge discriminating apparatus 101 specifies the attenuation rate with respect to the distance, and attenuates the stored first signal SIG1 based on the attenuation rate to generate the third signal SIG3. Further, as in the case of using the first signal SIG1, the partial discharge determination device 101 compares the third signal SIG3 and the second signal SIG2, and determines whether or not the second signal SIG2 has partial discharge.

  When the partial discharge determination device 101 generates the third signal SIG3, the partial discharge determination device 101 can accurately determine the partial discharge generated at an arbitrary distance. Further, since the partial discharge discriminating apparatus 101 generates the third signal SIG3, the first signal SIG at the point corresponding to the third signal SIG3 is not necessary, and the work load for injecting pulses by connecting the pulse generator 103 is reduced. it can.

  The partial discharge discriminating apparatus 101 may calculate the distance at which partial discharge occurs.

  FIG. 19 is a diagram illustrating an example of a method of calculating the distance of the partial discharge generation source by the partial discharge determination device according to the embodiment of the present invention.

  The partial discharge discriminating apparatus 101 stores, for example, a first signal SIG or a third signal SIG3 at six points as illustrated. That is, the partial discharge signal data DP0 at the measurement point P0, the partial discharge signal data DP100 at the point where the distance is 100 m, the partial discharge signal data DP200 at the point where the distance is 200 m, and the partial discharge signal data DP300 at the point where the distance is 300 m. The partial discharge signal data DP400 at a point where the distance is 400 m and the partial discharge signal data DP500 at a point where the distance is 500 m are the first signal SIG1, based on the pulse generated by the pulse generator 103, as shown in FIG. This is data stored in the partial discharge discriminating apparatus 101 by the third signal SIG3 based on the attenuation rate shown in FIG.

  For example, the case where the second signal SIG2 of the second signal data DSIG2 illustrated in FIG. 19 is measured in step S02 will be described.

  In step S03, the partial discharge discriminating apparatus 101 compares the partial discharge signal data at each point and the second signal data DSIG2, respectively, obtains a probability value, and determines the point having the highest probability value as the partial discharge source. Judged as distance.

  For example, in FIG. 19, the probability value of the second signal data DSIG2 with respect to the partial discharge signal data DP0 at the measurement point P0 is “60%”. Similarly, in FIG. 19, the probability value of the second signal data DSIG2 with respect to the partial discharge signal data DP100 at a point where the distance is 100 m is “75%”. Similarly, in FIG. 19, the probability value of the second signal data DSIG2 with respect to the partial discharge signal data DP200 at the point where the distance is 200 m is “90%”. Similarly, in FIG. 19, the probability value of the second signal data DSIG2 with respect to the partial discharge signal data DP300 at the point where the distance is 300 m is “75%”. Similarly, in FIG. 19, the probability value of the second signal data DSIG2 with respect to the partial discharge signal data DP400 at a point where the distance is 400 m is “60%”. Similarly, in FIG. 19, the probability value of the second signal data DSIG2 with respect to the partial discharge signal data DP500 at the point where the distance is 500 m is “40%”. Accordingly, in FIG. 19, since the probability value of the second signal data DSIG2 with respect to the partial discharge signal data DP200 at the point where the distance is 200 m is the highest value, the partial discharge discriminating apparatus 101 determines that the source of partial discharge is the distance. Is determined to be at a point of 200 m.

  The partial discharge discriminating apparatus 101 compares the partial discharge signal data at each point with the second signal data. Therefore, the partial discharge discriminating apparatus 101 can calculate the distance of the partial discharge generation source.

  The partial discharge discriminating apparatus 101 is not limited to using six points of data. A configuration using data of six or more measurement points or less than six measurement points may be used.

<Functional configuration example>
FIG. 20 is a functional block diagram illustrating an example of a functional configuration of the partial discharge determination device according to the embodiment of the present invention.

  The partial discharge determination apparatus 101 includes a storage unit 101F1, a measurement unit 101F2, a determination unit 101F3, a probability value calculation unit 101F4, and a mapping unit 101F5.

  The storage unit 101F1 stores various data such as data related to the first signal SIG1 and various parameters. The storage unit 101F1 is realized by, for example, the storage device 101H2. The storage unit 101F1 outputs the data of the first signal SIG1 shown in FIG. 5 and the like, the parameter PARSIG1 which is various numerical values of the first signal SIG1 shown in FIG. 6 and the like, or the pulses generated by the pulse generator 103 shown in FIG. One signal SIG1 is stored as data. In addition, the storage unit 101F1 stores data of the third signal SIG3 in FIGS. 18 and 19.

  The measurement unit 101F2 measures the alternating current flowing through the power facility, and measures the second signal SIG2. The measurement unit 101F2 is realized by, for example, the partial discharge measurement device 100 and the input I / F 101H3.

  The determination unit 101F3 determines whether or not the second signal SIG2 is a partial discharge based on at least one of the characteristic parameters indicated by the various parameters PARSIG1 by the process of step S03. The determination unit 101F3 is realized by, for example, the CPU 101H1.

  The probability value calculation unit 101F4 calculates the probability value of the second signal SIG2 measured by the measurement unit 101F2 based on the data stored in the storage unit 101F1. The probability value calculation unit 101F4 is realized by, for example, the CPU 101H1.

  The mapping unit 101F5 performs the mapping illustrated in FIG. 11 based on the probability value calculated by the probability value calculation unit 101F4. The mapping unit 101F5 is realized by, for example, the CPU 101H1.

  The partial discharge discriminating apparatus 101 compares the first signal SIG1 and the like based on the data stored in the storage unit 101F1 and the second signal SIG2 measured by the measurement unit 101F2 with the probability value calculated by the probability value calculation unit 101F4 and the like. It is determined whether or not the two signal SIG2 is partial discharge. The partial discharge discriminating apparatus 101 accurately discriminates whether or not the second signal SIG2 is a partial discharge because the comparison is performed using the characteristic parameter based on the data of the first signal SIG1 stored in the storage unit 101F1. be able to.

  Further, the probability value calculation unit 101F4 calculates the probability value, and the mapping unit 101F5 performs mapping based on the probability value, whereby the partial discharge can be accurately determined from the mapping shown in FIG.

  As described above, the storage unit that stores data indicating the first characteristic of the first signal level of the first partial discharge with respect to the time or frequency according to the exemplary embodiment of the present invention, and the discharge generated by the alternating current flowing through the power facility Measuring the second signal level and measuring the second characteristic of the second signal level of the alternating current with respect to time or frequency, and using the characteristic parameter based on the time or signal level, the first characteristic and Although the partial discharge discriminating apparatus having the discriminating unit that compares the second characteristic and discriminates whether or not the discharge is the first partial discharge has been described, the present invention is specifically disclosed. The present invention is not limited to this embodiment, and various modifications or changes can be made without departing from the scope of the claims.

DESCRIPTION OF SYMBOLS 100 Partial discharge measuring device 101 Partial discharge discriminating device 101F1 Memory | storage part 101F2 Measuring part 101F3 Discriminating part 101F4 Probability value calculating part 101F5 Mapping part 103 Pulse generator 104 φ-QN measuring board 105 Detection processing circuit 106 Filter 107 Phase detection sensor 108 Phase signal processing circuit SIG1 First signal SIG2 Second signal SIG3 Third signal BL Reference value T1 Time when the voltage value starts to change from the reference value BL T2 Time when the voltage value becomes the maximum value T3 Time when the voltage value becomes the minimum value G1 1st group G2 2nd group G3 3rd group P0 Measurement point P1, P2 Point DAR Attenuation rate DP0 Measurement data DP100 Partial discharge signal data at a point where the distance is 100 m DP200 Partial discharge signal data at a point where the distance is 200 m DP30 Distance point of the partial discharge signal data is a partial discharge signal data DP500 distance 500m point partial discharge signal data DP400 distance point is 300m is 400m

Claims (11)

A storage unit for storing data indicating the first characteristic of the first signal level of the first partial discharge with respect to time or frequency;
A measurement unit that measures a second signal level of a discharge generated by an alternating current flowing through the power facility, and measures a second characteristic of the second signal level of the alternating current with respect to time or frequency;
A determination unit that compares the first characteristic and the second characteristic using a characteristic parameter based on time or a signal level, and determines whether or not the discharge is the first partial discharge ;
The characteristic parameters include two or more including a first characteristic parameter and a second characteristic parameter,
Based on the first characteristic parameter, the first probability value calculated based on the degree of similarity of the probability that the discharge is the first partial discharge, and on the basis of the second characteristic parameter, the discharge is the first partial discharge. A probability value calculation unit for calculating a second probability value calculated based on the similarity to the probability of being a discharge,
A partial discharge discriminating apparatus , comprising: a mapping unit that maps the discharge point to the second probability value with respect to the first probability value . The apparatus further includes a conversion unit that frequency-converts the first characteristic of the first signal level of the first partial discharge with respect to the time and frequency-converts the second characteristic of the second signal level of the discharge with respect to the time. And
The determination unit compares the first characteristic frequency-converted by the conversion unit with the second characteristic frequency-converted by the conversion unit, and determines whether the discharge is the first partial discharge. The partial discharge discrimination device according to claim 1. When the first characteristic is indicated by voltage or signal strength with respect to time,
The first characteristic parameter and the second characteristic parameter are a maximum value of the absolute value of the voltage, a reference value that is a reference value for the voltage to indicate the voltage, and a time until the voltage reaches the maximum value. The first time, the amount of change of the voltage per unit time, the second time required for the absolute value of the voltage to become the minimum value from the maximum value, the voltage changes from the reference value to become the reference value 3. The partial discharge determination device according to claim 1, wherein the partial discharge determination device is any one of a third time, a ratio between the first time and the third time, and the signal intensity per unit time. When the first characteristic is indicated by signal strength with respect to frequency,
The partial discharge discriminating apparatus according to claim 1 or 2, wherein the first characteristic parameter or the second characteristic parameter is a signal intensity with respect to a frequency of the first characteristic. A pulse generator for injecting into the power equipment a pulse for generating the discharge indicating a partial discharge is connected to the power equipment;
5. The portion according to claim 1, wherein the first characteristic is obtained by measuring the discharge generated by the pulse that is injected into the power equipment by the pulse generator when the pulse generator is driven. Discharge discrimination device. The pulse generator injects the pulse at a first point where the pulse generator is connected to the power facility;
The storage unit stores a plurality of data obtained by measuring the discharge generated at the first point where the distance between the first point and the second point where the measuring unit is connected to the power facility is different. And
The determination unit calculates an attenuation rate indicating attenuation of the first signal level with respect to a distance, and uses the attenuation rate to determine the third signal level of the second partial discharge generated at a predetermined distance with respect to time or frequency. Calculating the first characteristic parameter or the second characteristic parameter based on three characteristics, and using the first characteristic parameter or the second characteristic parameter to compare the second characteristic and the third characteristic; The partial discharge determination device according to claim 5, wherein the discharge determines whether the discharge is the first partial discharge or the second partial discharge.   The partial discharge discriminating apparatus according to any one of claims 1 to 6, wherein the first characteristic is a characteristic of the second signal level of the discharge with respect to time or frequency. The partial discharge discriminating apparatus according to claim 3 , wherein a signal intensity per unit time is used for the first characteristic parameter or the second characteristic parameter .   The partial discharge determination apparatus according to claim 1, wherein the similarity is calculated by pattern matching each graph showing the first characteristic and the second characteristic.   Group the points,
  The partial discharge discriminating apparatus according to claim 1, wherein the discharge indicated by the point is shown in a distribution diagram for each group. Partial discharge measuring device
A storage procedure for storing data indicative of a first characteristic of the first signal level of the first partial discharge with respect to time or frequency;
A measurement procedure for measuring a second signal level of a discharge generated by an alternating current flowing through the power facility, and measuring a second characteristic of the second signal level of the alternating current with respect to time or frequency;
Using a characteristic parameter based on time or signal level, comparing the first characteristic and the second characteristic, and determining whether or not the discharge is the first partial discharge ;
The characteristic parameters are two or more including a first characteristic parameter and a second characteristic parameter,
Based on the first characteristic parameter, the first probability value calculated based on the degree of similarity of the probability that the discharge is the first partial discharge, and on the basis of the second characteristic parameter, the discharge is the first partial discharge. A probability value calculation procedure for respectively calculating a second probability value obtained by calculating the probability of being a discharge based on the similarity;
A partial discharge discrimination method comprising: a mapping procedure for mapping the discharge point to the second probability value with respect to the first probability value .