JP2662406B2 - Data collection device for partial discharge measurement device - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a data collection device for a partial discharge measuring device capable of automatically obtaining characteristic data of a partial discharge generated inside an electrical equipment insulation system. It is about. 2. Description of the Related Art A partial discharge measuring device is widely used for detecting a pulse current accompanying a partial discharge generated inside an electrical equipment insulation system and early detecting insulation failure or deterioration of the electrical equipment insulation system. It is necessary for such a partial discharge measuring apparatus to be able to accurately collect all necessary partial discharge characteristic data within a short time as possible. [Prior Art] In order to detect insulation failure or deterioration of an electrical equipment insulation system, it is necessary to measure the magnitude and number of partial discharge pulses generated with partial discharge. For this reason, in the conventional measuring method, the partial discharge measuring device is provided with a variable attenuator for attenuating the magnitude of the partial discharge pulse in a stepwise manner and a rotary switch for selecting an attenuation rate of the variable attenuator. The measurer selects this rotary switch so as to measure a partial discharge pulse of a predetermined size, and determines the number of partial discharge pulses generated per unit time at that time. Reading by a counter connected to the measuring device has made it possible to determine insulation failure or deterioration. [Problems to be solved by the invention] In order to analyze the insulation failure and deterioration of the electrical equipment insulation system in detail and to follow the aging, plot the magnitude and number of partial discharge pulses generated. Several methods are commonly used. In such a case, if the conventional measurement method is used, the load becomes extremely large because the measurer must select the rotary switch and read and record the count value of the counter each time. There was a problem. This problem was even greater when averaging multiple measurements to improve the accuracy of the measurements. The present invention has been made in view of such circumstances,
It is an object of the present invention to provide a data collection device of a partial discharge measuring device which enables accurate collection of all necessary partial discharge characteristic data within a time as short as possible. [Means for Solving the Problems] FIG. 1 shows a configuration of the present invention which is adopted to solve such problems. In the figure, reference numeral 1 denotes a test specimen whose partial discharge is measured by application of a test voltage, and 10 detects a partial discharge pulse generated by the test specimen 1 and tunes a partial discharge pulse of a specific frequency component of the partial discharge pulse. A partial discharge measuring device 20 for generating a counting pulse corresponding to the detection output of the pulse is a data collecting device for collecting characteristic data of the partial discharging measuring device 10 regarding the counting pulse. The partial discharge measurement device 10 includes a tuning detector denoted by 11, a variable attenuator denoted by 12, a tuning amplifier denoted by 13, a detector denoted by 14, and a comparator denoted by 15. . The tuning detector 11 detects the partial discharge pulse emitted from the specimen 1, the variable attenuator 12 attenuates the partial discharge pulse detected by the tuning detector 11 in a stepwise manner, and the tuning amplifier 13 uses the variable attenuator 12 to reduce the partial discharge pulse. The specific frequency component of the attenuated partial discharge pulse is extracted and amplified, the detector 14 detects the specific frequency component of the partial discharge pulse extracted by the tuning amplifier 13, and the comparator 15 detects the detection output of the detector 14. By comparing with a predetermined reference voltage, a counting pulse corresponding to a tuning partial discharge pulse exceeding the reference voltage is generated. The data collection device 20 includes a processor unit indicated by 21, a counter unit indicated by 22, a variable attenuator control unit indicated by 23, and a data storage unit indicated by 24. The processor means 21 controls the counter means 22, the variable attenuator control means 23, and the data storage means 24,
The counter means 22 counts the counting pulse generated by the partial discharge measuring device 10, the variable attenuator control means 23 controls the attenuation rate of the variable attenuator 12 of the partial discharge measuring device 10, and the data storage means 24 , The count value of the counting pulse counted by the counter means 22 is stored. [Operation] In the present invention, the processor means 21 controls the variable attenuator control means 23 at predetermined time intervals to change the attenuation rate of the variable attenuator, thereby changing the number of generated counting pulses. , The counter 22 reads the integrated value of the counting pulse at the predetermined time interval, and stores it in the data storage 24. Therefore, according to the present invention, the magnitude and the number of partial discharge pulses representing the characteristic data of the partial discharge generated inside the electrical equipment insulation system can be collected automatically and accurately. Further, according to the present invention, these collected data are stored, so that various data processing can be performed and recording on a plotter or the like can be realized. Can be analyzed EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples. FIG. 2 shows a system configuration diagram of a data collection device of the partial discharge measuring device of the present invention. In the figure, 1 is a specimen, 2 is an applied power source, 10 is a partial discharge measuring device, and 20 is a data collection device.
Specimen 1 is an electrical equipment insulation system in which a partial discharge is to be measured. Applied power supply 2 is a power supply device for applying a test voltage to generate a partial discharge to this specimen 1, a partial discharge measuring device. 10 is a measuring device for measuring a partial discharge pulse generated by the specimen 1 without being affected by interference waves such as a radio broadcast wave, and a data collecting device 20 is a device for counting pulses generated by the partial discharge measuring device 10. Is a computer system for collecting data. As shown in this figure, the data collection device 20 is a partial discharge measurement device.
Measuring unit 31 that constitutes an interface with 10
A computer 32 for executing data processing, a communication line 33 connecting the measuring unit 31 and the computer 32, a console 34 comprising a CRT and a keyboard constituting a man-machine interface, and a floppy disk 35 for storing necessary data. , And a dot printer 36 for recording the collected data. FIG. 3 shows a system configuration diagram of the measurement unit 31 constituting the data collection device 20. As shown in FIG. 3, the measurement unit 31 includes a CPU 31a, a counter 31b, a digital voltmeter 31c, a DIO 31d, a ROM 31e, a RAM 31f, and a communication interface 31g.
A counting function for counting a counting pulse where the pulse occurs in response to the partial discharge pulse, an ATT level setting function for setting an attenuation rate of a variable attenuator of the partial discharge measuring device 10 described later, This implements a test voltage monitoring function of reading a test voltage applied from the power supply 2 to the specimen 1. Here, this counting function is realized by the counter 31b, the ATT level setting function is realized by the ATT code transmitted via the DIO 31d, and the test voltage monitoring function is realized by the digital voltmeter 31c. Next, the operation of the partial discharge measurement device 10 to be combined with the data collection device 20 of the present invention will be described with reference to the circuit configuration diagram of the partial discharge measurement device 10 shown in FIG.
The partial discharge pulse generated inside the specimen 1 is transmitted through the coupling capacitor 3 and the coaxial cable 4 to the partial discharge measuring device.
10 will be entered. As described with reference to FIG. 1, the tuning detector 11 detects the partial discharge pulse, and the subsequent variable attenuator 12 applies the partial discharge pulse detected by the tuning detector 11 to the ATT signal from the measurement unit 31. The signal is attenuated with the attenuation factor specified by the code, and is input to the next-stage tuning amplifier 13. This tuning amplifier 13
It is configured as a tuned partial discharge measuring circuit known in Japanese Patent Publication No. 42-23236, etc., and has a frequency band of little interference radio waves such as 400 KHz ±.
It is configured to have an amplification function at 45 KHz. Therefore, the partial discharge pulse attenuated by the variable attenuator 12 is 400 KHz
In addition to being converted to a vibration pulse, the pulse is attenuated with a decay time of about 20 μs by a bandwidth of ± 45 KHz, so that the pulse resolution can be increased. Following detector 14
Detects a partial discharge pulse converted into a vibration pulse of a specific frequency component by the tuning amplifier 13, and a comparator 15 compares the detected output with a predetermined reference voltage to generate a counting pulse. Will be. The counting pulse generated by the partial discharge measuring device 10 in this manner is
Is expressed without being affected by the jamming radio waves. Reference numeral 16 enclosed by a broken line is a gate circuit for discriminating the polarity of the partial discharge pulse. FIG. 5 shows an embodiment of a specific configuration of the variable attenuator 12 constituting the partial discharge measuring device 10. In the embodiment shown in FIG. 5, the variable attenuator 12 includes a selector switch 12a, a NOR gate 12b, a decoder 12c, and a code conversion gate 12d. The decoder 12c decodes the ATT code input from the measurement unit 31 via the code conversion gate 12d, and sets the selector switch 12a to NOR.
The branch point of the resistor connected in series is selected according to the decode signal input through the gate 12b. Thereby, the operation is performed so that the attenuation rate of the variable attenuator 12 is determined. FIG. 5 also shows an example of a code table for executing the switching. FIG. 6 shows a change in the detection output of the detector 14 when the attenuation rate is changed in this manner when the magnitude of the input partial discharge pulse is constant. As shown in this figure, the partial discharge pulse is attenuated by the instruction of the ATT code from the measurement unit 31, and is compared with the reference voltage of the comparator 15 to generate a counting pulse. Next, in accordance with the flowchart shown in FIG. 7, the data collection device 20 for collecting the characteristic data of the partial discharge of the present invention.
The operation performed by the computer 32 will be described. The computer 32 first receives a request for data collection from the operator, as shown in step 1, and starts the console 34.
Display graph frame and scale for displaying characteristic data on CRT. Subsequently, in step 2, the ATT is adjusted so that the attenuation rate of the variable attenuator 12 becomes the initial level with the smallest attenuation.
By setting the code and sending this ATT code to the code conversion gate 12d of the variable attenuator 12 via the measurement unit 31, the attenuation factor of the variable attenuator 12 is set to this initial level. In step 3, the number of counting pulses per unit time at which the partial discharge measuring device 10 generates at this attenuation rate is counted by the counter 31b of the measuring unit 31, and the count value is read via the communication line 33. Execute If it is determined in the subsequent step 4 that the count value is not "0", the test voltage value at that time is measured by the digital voltmeter 31c of the measurement unit 31 in a step 5, and in the subsequent step 6, The count value measured in the process of step 3 and the voltage value measured in the process of step 5 are displayed on the CRT, and are temporarily stored in the memory of the computer 32. With the above processing, the number of generated partial discharge pulses per unit time having a magnitude of, for example, 0.5 pico clones or more is obtained. Then, in step 7, the computer 32 sets an ATT code so as to increase the attenuation rate of the variable attenuator 12 by one step, and executes the same processing as the processing in step 2 to change the variable attenuator 12 to this attenuation rate. Set to. Then, returning to step 3, the processes from step 3 to step 6 are repeatedly executed. By executing this process, the number of generated partial discharge pulses per unit time, which is one step larger, for example, 1.0 pico clone or more, is obtained. When the attenuation rate of the variable attenuator 12 is increased in this way, the reference voltage of the comparator 15 exceeds the maximum value of the tuned partial discharge pulse. The count value of the discharge pulse becomes “0”. If the count value is determined to be "0" in the determination in step 4, step 8
To determine whether or not there is a designation for repeated measurement.
If it is determined in step 8 that there is a repeated measurement request, the process returns to step 2 and the same measurement is repeated. FIG. 8 shows an example of a printout of the measurement data of the partial discharge pulse measured in this way. In this example, repeated measurements are performed five times. These obtained characteristic data are transferred to and stored on the floppy disk 35 in accordance with a request from the measurer. The magnitude of the partial discharge pulse, such as 0.5 pico clone, specified by the attenuation factor of the variable attenuator 12 is, as shown in FIG. 4, a partial discharge calibrator 40 that generates a calibrated partial discharge pulse. Is connected in parallel with the test sample 1 and is adjusted by using an adjustment resistor (not shown) provided in the variable attenuator 12 so as to accurately reach the value. The printout data shown in FIG. 9 shows an example of the characteristic data when the test voltage is changed. In this example, the operator manually changes the test voltage so that the data collection device 20 collects the characteristic data. It is needless to say that such characteristic data can also be collected. FIG. 10 is a printout of the characteristic data of FIG. 9 as a graph. Although the detailed description is omitted, the graph displayed on the CRT by the process of step 6 in FIG. 7 is also such. As apparent from FIG. 10, according to the present invention, the characteristics of the partial discharge generated by the specimen 1 can be understood at a glance.
Further, if such data is stored in the floppy disk 35, the secular change of the characteristic of the partial discharge can be observed, so that it is possible to accurately determine the insulation failure or deterioration of the specimen. In the description of the present invention, the configuration example in which the attenuation rate of the variable attenuator 12 is controlled in a stepwise manner has been described. However, the present invention can also be implemented by changing the reference voltage of the comparator 15 in a stepwise manner. It is. However, in this method, when the reference voltage changes in a wide range (dynamic range), accurate measurement becomes difficult due to the influence of noise on small signals and the influence of saturation on large signals. On the other hand, the method of controlling the attenuation rate of the variable attenuator 12 according to the present invention can increase the dynamic range to 1000 times or more, and can perform accurate measurement even when a small signal and a large signal are mixed. In addition, the configuration of the measuring instrument can be simplified, and a more practical configuration can be achieved. [Effects of the Invention] As described above, according to the present invention, the magnitude and the number of partial discharge pulses representing the characteristic data of the partial discharge generated inside the electrical equipment insulation system are automatically and accurately determined. Will be able to collect. Moreover, collection can be performed in an extremely short time as compared with the related art. Furthermore, according to the present invention, various data processing can be performed on the characteristic data, and the characteristic data can be immediately recorded in an easy-to-read format using a plotter or the like. And degradation can be analyzed in detail.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram illustrating the principle of the present invention, FIG. 2 is a system configuration diagram of the present invention, FIG. 3 is a system configuration diagram of a measurement unit, and FIG. 4 is a circuit of a partial discharge measurement device. FIG. 5 is a block diagram of an embodiment of a variable attenuator, FIG. 6 is an operation explanatory diagram showing a change in detection output when the attenuation rate of the variable attenuator changes, and FIG. 7 is the present invention. 8 is an explanatory diagram showing an example of the measured data, FIG. 9 is an explanatory diagram showing another example of the measured data, and FIG. 10 is an example of a graph display of the measured data in FIG. FIG. In the figure, 1 is the specimen, 2 is the applied power, 10 is the partial discharge measurement device, 11
Is a tuning detector, 12 is a variable attenuator, 13 is a tuning amplifier, 14 is a detector, 15 is a comparator, 20 is a data acquisition device, 31 is a measurement unit, and 32 is a computer.

Claims (1)

(57) [Claims] A variable attenuator for attenuating the magnitude of the partial discharge pulse emitted from the test specimen to which the test voltage is applied; A partial discharge measuring device for comparing the detected output with a predetermined reference voltage; counter means for counting the counting pulses from the partial discharge measuring device; and an attenuation factor of the variable attenuator provided in the partial discharge measuring device. Variable attenuator control means for controlling the counter, data storage means for storing the count value of the counting pulse counted by the counter means, and a processor for controlling the counter means, the variable attenuator control means, and the data storage means Means, the processor means controlling the variable attenuator control means at a predetermined time interval, The number of pulses for counting is changed by changing the attenuation rate of the attenuator, and the integrated value of the counting pulses at the predetermined time interval counted by the counter is read and stored in the data storage. A data collection device for a partial discharge measurement device, characterized in that the data collection device is controlled to perform the measurement.