JP2020051901A - Test system and test method for protective relay - Google Patents

Abstract

To provide a test device and a test method, capable of objectively and accurately testing a protective relay installed in a site electric facility.SOLUTION: A test system 100 comprises a protective relay tester 102, a controller 104, and a temperature sensor 106 that measures a temperature of an environment in which a protective relay 202 is installed. The protective relay tester supplies a predetermined test signal to the protective relay, acquires an operation signal output from the protective relay, calculates an operation time from the operation signal, and then transmits it, and the control device receives the operation time, a relay drive voltage and the measured temperature, calculates an evaluated value from the operating time, the relay drive voltage and the measured temperature, compares the evaluated value with a predetermined reference value, and thus determines the state of the protective relay. Consequently, the quality of the protective relay can be determined objectively and accurately.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a test system and a test method capable of objectively and accurately testing a protective relay installed in an electric facility at a special high-voltage or high-voltage site.

  The protective relay detects a short circuit or ground fault accident that has occurred in the power equipment that composes the power system through the instrument transformer, and sends a control signal to a circuit breaker etc. in order to quickly disconnect the fault section from the power system. It is a device for outputting. With the protective relay, it is possible to suppress the influence of the short circuit or ground fault accident from spreading.

  Periodic inspection of protective relays is carried out using a dedicated protective relay tester. That is, a protection relay tester is connected to a protection relay installed on site electrical equipment, a test current or a test voltage is supplied from the protection relay tester to operate the protection relay, and a signal output from the protection relay (hereinafter, referred to as a signal output from the protection relay). Based on the operating signal), the characteristics of the protective relay are confirmed. In general, the tester operates the protective relay tester, and determines whether the protective relay is operating within the range of the control value, and based on the input of the test current (test voltage) and the relay operation of the protective relay. The tester visually checks the result (numerical value) displayed on the protective relay tester to determine whether the operation time up to the contact output is within the management value.

  Regarding the test and inspection of a protection relay, for example, Patent Literature 1 below stores a management value of an operation time and an operation value in a protection relay itself in a protection relay test system, and protects a test procedure (test items and test conditions). A configuration is disclosed in which the test result is stored in one of a relay and a test device, and the test device compares the value of the test result with a control value.

Patent No. 3265337

Makoto Hojingo, "Introduction to the Distance of Mahalanobis", Quality Engineering, Volume 9, 2001, PP.13-21, [Search on July 20, 2018], Internet <URL: https: //www.jstage.jst.go .jp / article / qes / 9/1 / 9_13 / _pdf / -char / ja>

  However, if the protection relay to be measured does not store the management value, the test according to the technology disclosed in Patent Document 1 cannot be executed. In addition, in the method of simply comparing the test result with the control value to determine the quality, the test result is within the control value range, but is determined to be “good” even when the test result is near the boundary, and the deterioration tendency and the deterioration There is a problem that it is not possible to determine whether or not there is a possibility. For example, when the test results are A + 4.8% and A-4.9% with respect to the control value A ± 5% (A is a predetermined value according to the test), the deterioration is due to the vicinity of the control value boundary. Despite what you may be doing, there is no standard to judge it.

  Therefore, an object of the present invention is to provide a test system and a test method that can objectively and accurately test a protective relay installed in an electric facility.

  A test system according to a first aspect of the present invention includes a protection relay tester, a control device that communicates with the protection relay tester, and a temperature sensor that measures a temperature of an environment in which the protection relay to be tested is installed. Including. Under the control of the control device, the protection relay tester obtains an output unit that supplies a predetermined test signal to the protection relay and an operation signal output from the protection relay due to the operation of the protection relay due to the supply of the test signal. An input unit for calculating the operation time of the protection relay from the operation signal, and a communication unit for transmitting the operation time to the control device. The control device receives the operation time, the temperature measured by the temperature sensor, the relay drive voltage generated by the power supply to the protection relay, and a receiving unit, and calculates the evaluated value from the operation time, the relay drive voltage and the measured temperature, and A determination unit that determines a state of the protection relay by comparing the value with a predetermined reference value.

  In this way, the tester can automatically execute the protection relay test by instructing the controller to execute the test without directly operating the protection relay tester and performing individual tests. Can be determined.

  The relay drive voltage generated by the power supply to the protection relay may be obtained by an input of the protection relay tester.

  Preferably, the reference value is a Mahalanobis distance determined from a set of samples including an operation time and a relay driving voltage that are test results of a normally operating protection relay, and a measured temperature of an environment in which the protection relay is installed. And the evaluated value is the Mahalanobis distance calculated from the set of operating time, relay drive voltage, and measured temperature received by the receiving unit. The judging unit judges that the protection relay to be tested is normal if the evaluated value is equal to or less than the reference value, and if the evaluated value is larger than the reference value, the protection relay to be tested may be abnormal. It is determined that there is a possibility.

  Thereby, the quality of the protection relay can be accurately determined.

  More preferably, the reference value is a product of a standard deviation calculated from a set of one sample of the operation time and the relay drive voltage, which is a test result of the normally operating protective relay, and a predetermined coefficient, and the predetermined coefficient is , 0.1 or more and 3 or less. The evaluated value is an average value calculated from a set of one of the samples, and one of the operation time and the relay drive voltage received by the receiving unit, the value corresponding to the set from which the standard deviation is calculated. And the difference. The determining unit determines that the protection relay to be tested is normal if the absolute value of the difference is equal to or less than the reference value, and that the protection relay to be tested is abnormal if the absolute value of the difference is greater than the reference value. Is determined to be possible.

  Thereby, the quality of the protection relay can be accurately determined.

  The test system according to the second aspect of the present invention is a protection relay tester, a control device that communicates with the protection relay tester, a temperature sensor that measures the temperature of the environment in which the protection relay to be tested is installed, It includes an imaging device provided in the protection relay for imaging an area including an LED, and a lighting information generation device that detects lighting of the LED from an image captured by the imaging device and generates lighting information. The protection relay tester is controlled by the control device, and outputs a predetermined test signal to the protection relay by gradually increasing or decreasing the value of the test signal, and a test signal from the lighting information generation device. An acquisition unit that acquires lighting information of an LED that is turned on in accordance with the operation of the protection relay by the supply of the protection relay; and, when the acquisition information is acquired by the acquisition unit, a value of the test signal supplied from the output unit. It has a determining unit that determines an operation value and a communication unit that transmits the operation value to the control device. The control device is configured to receive the operating value and the temperature measured by the temperature sensor, and to calculate the evaluated value from the operating value and the measured temperature, and to compare the evaluated value with a predetermined reference value, thereby providing protection. A determination unit for determining a state of the relay.

  In this way, the tester can automatically execute the protection relay test by instructing the controller to execute the test without directly operating the protection relay tester and performing individual tests. Can be determined. Further, the pass / fail judgment of the protection relay can be performed more easily than when the operation signal of the protection relay is received.

  A test method according to a third aspect of the present invention is a method for testing a protective relay, comprising the steps of: acquiring a measured temperature of an environment in which the protective relay is installed; and controlling the protective relay tester by a control device. Causing the protection relay to supply a predetermined test signal; and, by the protection relay tester, acquiring an operation signal output from the protection relay along with the operation of the protection relay by the supply of the test signal. Calculating the operation time and the relay drive voltage of the protection relay from the operation signal; calculating a value to be evaluated from the operation time, the relay drive voltage and the measured temperature by the control device; and evaluating the value to be evaluated by the control device. Determining a state of the protection relay by comparing the protection relay with the predetermined reference value.

  In this way, the tester can automatically execute the protection relay test by instructing the controller to execute the test without directly operating the protection relay tester and performing individual tests. Can be determined.

  According to the present invention, the tester automatically performs the test of the protection relay by directly instructing the control device to execute the test without directly operating the protection relay tester and performing each test. In addition, the quality can be objectively determined. Therefore, the burden on the tester can be reduced.

  In addition, the value to be evaluated is a Mahalanobis distance calculated using a set of test results of normally operating protective relays, or a predetermined coefficient of a standard deviation calculated using a set of test results of normally operating protective relays. By comparing the value with the doubled value, the quality of the protection relay can be accurately determined. In addition, when the test result is located at the boundary of the control value, it can be prevented that the protection relay is determined to be “good” despite the fact that the protection relay tends to deteriorate.

FIG. 1 is a block diagram illustrating a configuration of a test system according to an embodiment of the present invention. It is a block diagram which shows the internal structure of the control apparatus of FIG. 1, and a protection relay tester. 2 is a flowchart illustrating a test of a protection relay performed by the control device of FIG. 1. 4 is a flowchart illustrating a pass / fail determination process in FIG. 3. It is a graph which shows the distance of Mahalanobis. 5 is a flowchart illustrating another pass / fail judgment process different from FIG. 4. FIG. 9 is a block diagram illustrating a configuration of a test system according to a first modification. It is a block diagram showing the composition of the test system concerning the 2nd modification. It is a schematic diagram which shows the front surface of a protection relay. FIG. 9 is a block diagram illustrating an internal configuration of a third wireless module of FIG. 8.

  In the following embodiments, the same components are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

(Configuration of test system)
With reference to FIG. 1, a protection relay test system (hereinafter, also simply referred to as a test system) 100 according to an embodiment of the present invention includes a protection relay tester 102, a control device 104 that controls the protection relay tester 102, And a temperature sensor 106. The protection relay tester 102 is a known tester for testing a protection relay. The test target of the protection relay tester 102 is a protection relay 202 arranged on the switchboard 200. The control device 104 receives the test result of the protection relay 202 from the protection relay tester 102, and directly receives a drive voltage (hereinafter, referred to as an internal relay drive voltage) when a relay inside the protection relay 202 operates from the protection relay 202. I do.

  The temperature sensor 106 is a sensor for measuring the temperature of the environment where the protection relay 202 is installed. The temperature sensor 106 includes a known sensor element such as a resistance temperature detector or a thermocouple. The output result of the temperature sensor 106 is input to the control device 104. If the output (temperature) of temperature sensor 106 is analog, control device 104 performs A / D conversion and stores it as digital data. When the temperature sensor 106 has an A / D conversion function and outputs digital data, the control device 104 stores the received data as it is.

  Although one protection relay 202 is shown in FIG. 1, a plurality of protection relays may be arranged on the switchboard 200. The protection relay tester 102 performs a test described below for each protection relay.

(Control device)
Referring to FIG. 2, control device 104 includes CPU 110, storage unit 112, IF unit 114, operation unit 116, display unit 118, and bus 120. The control device 104 is, for example, a computer. A CPU (Central Processing Unit) 110 controls the entire control device 104 and executes a protection relay test program described later. The CPU 110 may be a microcomputer (hereinafter, referred to as a microcomputer).

  The storage unit 112 stores data and is, for example, a rewritable nonvolatile semiconductor memory. The storage unit 112 stores a test program executed by the CPU 110. The storage unit 112 stores the data of the test result received from the protection relay tester 102. Data exchange between the units constituting the control device 104 is performed via the bus 120.

  The IF unit 114 is an interface for exchanging data with the outside. The IF unit 114 has a function for communicating with the protection relay tester 102, and can perform, for example, parallel communication (GPIB or the like) or serial communication (RS-232C or the like). The IF unit 114 has an A / D conversion function (A / D converter). When an analog signal is input from the temperature sensor 106, the IF unit 114 generates digital data and stores the digital data in the storage unit 112. Remember. The IF unit 114 also receives the internal relay drive voltage from the protection relay 202 and, when input as an analog signal, generates digital data and stores the digital data in the storage unit 112.

  The operation unit 116 is operated by a user and receives an input of an instruction. The operation unit 116 is, for example, a computer keyboard, a computer mouse, or the like. The display unit 118 displays information such as text and images, and is, for example, a liquid crystal display, a CRT, or the like.

(Protective relay tester)
2, the protection relay tester 102 includes a CPU 130, a storage unit 132, an IF unit 134, an operation unit 136, a display unit 138, an output unit 140, an input unit 142, and a bus 144. The CPU 130 controls the entire protection relay tester 102. CPU 130 may be a microcomputer.

  The storage unit 132 stores data and is, for example, a rewritable nonvolatile semiconductor memory. The storage unit 132 stores a program executed by the CPU 130. Further, as described later, the storage unit 132 stores the data (operation signal) received from the protection relay 202. Data exchange between the units constituting the protection relay tester 102 is performed via the bus 144.

  The IF unit 134 is an interface for exchanging data with the outside. The IF unit 134 has a function of communicating with the IF unit 114 of the control device 104, and can perform communication using a communication method such as GPIB or RS-232C, for example.

  The operation unit 136 is operated by a user and receives an input of an instruction. The operation unit 136 is, for example, a key (a switch, a button, or the like). The operation unit 136 may be a touch panel.

  The display unit 138 displays the state of the protection relay tester 102 and numerical values such as measured values. The display unit 138 is, for example, an LED, a 7-segment display for displaying numerical values, a liquid crystal display, or the like.

  The output unit 140 functions as a power supply that supplies a predetermined voltage or current as a test signal to the protection relay 202. The strength of the supplied test signal is determined with reference to the information stored in the storage unit 132 according to the test item.

  The input unit 142 measures an operation signal (contact output) output from the protection relay 202 when the protection relay 202 operates (for example, a relay is turned on) according to a test signal supplied to the protection relay 202. More specifically, the input unit 142 samples a continuously input analog signal at a predetermined period, converts the analog signal into digital data, transmits the digital data as measurement data to the storage unit 132 via the bus 144, and stores the same.

(Test method)
The test operation of the protection relay by the test system 100 will be described with reference to FIG. 3 is executed by the CPU 110 of the control device 104. That is, in response to the tester instructing the test of the protection relay via the operation unit 116, the CPU 110 reads out the test program from the storage unit 112 and executes it.

  The test program includes protection relay elements such as overcurrent elements (generally referred to as 51 elements, OC elements, etc., according to the control device number, etc.) as test items, and for each of a plurality of test items, the protection relay tester This is for causing the test 102 to sequentially execute tests. The test program is created including a command corresponding to the protection relay tester 102. At present, a general protection relay tester is provided with an external control port (a port for externally controlling the protection relay tester), and a control command is provided. Here, it is assumed that the test program includes a control command and its parameters (such as the strength of a test signal supplied from the output unit 140) as information for each test item (hereinafter also referred to as “test information”).

  In step 300, the CPU 110 acquires an output signal from the temperature sensor 106 and stores it in the storage unit 112 as temperature data.

  In step 302, the CPU 110 specifies one test item (protection relay element). Specifically, the CPU 110 selects one piece of untested test information from among a plurality of pieces of test information included in the test program. Thereby, the control command and its parameters are specified.

  In step 304, the CPU 110 transmits the test information (control command and its parameters) specified in step 302 to the protection relay tester 102 via the IF unit 114. The CPU 130 of the protection relay tester 102 receives the test information via the IF unit 134 and performs a test according to the received test information.

  Specifically, the CPU 130 of the protection relay tester 102 determines the type (voltage or current) and the signal strength of the test signal based on the received control command and parameter, and the determination is made via the output unit 140. The test signal is supplied to the protection relay 202. Thereafter, the CPU 130 receives, via the input unit 142, an operation signal generated as a result of the operation of the protection relay 202 supplied with the test signal (relay ON / OFF). The operation signal received for a predetermined time is stored in the storage unit 132 as digital data as described above. Further, CPU 130 reads the operation signal stored from storage unit 132, calculates a test result, and transmits the result to control device 104. For example, the CPU 130 supplies a test signal for turning on the relay inside the protection relay 202 to the protection relay 202 to measure and store the operation signal, and from the stored data (operation signal) to the operation time (after supplying the test signal) Time until the relay turns on). Regarding the relay drive voltage, the CPU 110 measures, via the IF unit 114, the internal relay drive voltage, which is the drive voltage when the relay inside the protection relay 202 operates, without passing through the protection relay tester 102. As will be described later, it is determined as a relay drive voltage and stored in the storage unit 112.

  In step 306, CPU 110 determines whether or not the test of the test item specified in step 302 has been completed. Specifically, CPU 110 determines whether or not a test result has been received from protection relay tester 102 via IF unit 114, or whether or not the internal relay drive voltage of protection relay 202 has been measured. If it is determined that the processing has been completed, the control proceeds to step 310. Otherwise, control proceeds to step 308.

  In step 308, the CPU 110 determines whether or not a predetermined time has elapsed since the transmission of the test information in step 304. If it is determined that the time has elapsed, the control proceeds to step 314. Otherwise, control returns to step 306. Thereby, CPU 110 waits for the test result transmitted from protection relay tester 102 until the predetermined time elapses, or repeats the measurement of the internal relay drive voltage of protection relay 202. The elapse of the predetermined time is obtained, for example, by acquiring the time at which the test information was transmitted in step 304 from an internal timer, storing the time in the storage unit 112 as a reference time, and each time step 308 is executed, the timer This can be performed by acquiring the time and comparing it with the reference time.

  In step 310, the CPU 110 stores the test result received from the protection relay tester 102 in step 306 or the internal relay drive voltage (relay drive voltage) of the protection relay 202 measured in step 306 in the storage unit 112.

  In step 312, CPU 110 determines whether or not the test has been completed, that is, whether or not all the test items have been executed. If it is determined that the processing has been completed, the control proceeds to step 316. Otherwise, control returns to step 302, where an untested test item is identified and the test is performed as described above. As a result, the test result for each test item is stored in the storage unit 112.

  On the other hand, if it is determined in step 308 that the predetermined time has elapsed before the test of the test item is completed, in step 314, the CPU 110 executes error processing. For example, the CPU 110 displays on the display unit 118 that an error has occurred. Thereafter, the program ends. As a result, the tester can carry out a retest or respond to an error.

  In step 316, the CPU 110 executes the pass / fail determination process using the test result (including the relay drive voltage) and the temperature data stored in the storage unit 112. Specifically, CPU 110 executes the processing shown in FIG.

  In step 400, the CPU 110 reads from the storage unit 112 the normal Mahalanobis distance D0 calculated from the set of measurement samples related to the normal protective relay. Mahalanobis distance is one of distance measures in a multivariate (multidimensional) space and is known (for example, see Non-Patent Document 1).

For example, assuming that the normalized correlation coefficient between the two parameters X and Y is r, the Mahalanobis distance D is obtained by Expression 1.
^{D 2 = (X 2 -2rXY +} Y 2) / {k (1-r 2)} ··· ( Equation 1)
Here, k = 2 (the number of parameters). The normalized value is calculated by dividing the difference from the average value by the standard deviation. For example, the normalized value _{X i} of the measurement data _{x i,} using the average value mu _x and a standard deviation sigma _x, is calculated by _{X i = (x i -μ x} ) / σ x.

  FIG. 5 schematically shows the relationship between the measurement data and the Mahalanobis distance. In FIG. 5, square points are plots of measured values (normalized values) of two parameters, and each of the ellipses 220, 222, and 224 has a constant Mahalanobis distance value (hereinafter, “equal Mahalanobis distance”). "). For example, if D = 2.0 for a point on the ellipse 220, the size of the ellipse is small, such as D = 1.5 for a point on the ellipse 222 and D = 1.0 for a point on the ellipse 224. Indeed, the value of the distance of equal Mahalanobis becomes smaller.

Here, data on test results for normal protective relays are collected, and the data (a set of measurement samples) is used to calculate the Mahalanobis distance as described above. Is determined, and stored in the storage unit 112. For example, the same protection relay element (for example, 51 elements, etc. under the same setting conditions (test conditions), such as past in-house test data and on-site test data, including those having different types of protection relays) ), And a set (each data is a normalized value) composed of data of the ambient temperature of the protection relay measured at the time of measuring each of the pass data. A plurality of parameters (protection relay elements) P _i (where i is an integer of i = 1 to n; n is the number of parameters) are determined, and among the data in the set, the determined parameters P _i (i = 1 to n) ), And a set of mutually corresponding data p _ij {p _1j , p _2j ,..., P _nj } (j represents a set, j = 1 to an integer of 1 to m. The number of Mahalanobis is calculated for each of the numbers. Then, a closed surface of the Mahalanobis distance (ellipse in the case of two dimensions) including all the data {p _1j , p _2j ,..., P _nj } (j = 1 to m) used for calculating the Mahalanobis distance Is determined, and the Mahalanobis distance representing the closed surface is defined as the normal Mahalanobis distance D0. That is, all data used for calculating the Mahalanobis distance are located in a space surrounded by a closed curved surface whose Mahalanobis distance is D0. For example, the maximum value of the calculated Mahalanobis distance can be taken as the normal Mahalanobis distance D0.

  For example, the operating time and the relay driving voltage are determined as two parameters, the temperature is determined as a third parameter, and a point corresponding to a data set of these three parameters is determined from all the passing data. , The value of the Mahalanobis distance representing the curved surface of the Mahalanobis distance including these points is defined as the normal Mahalanobis distance D0. Not only a curved surface of Mahalanobis distance including all data used for calculating a distance of Mahalanobis but also a curved surface of Mahalanobis distance including a predetermined ratio (for example, 90%, 80%, etc.) of all data. The value of the Mahalanobis distance may be the Mahalanobis distance D0 in a normal state.

  In step 402, the CPU 110 reads the test result data stored in the storage unit 112 in step 310.

  In step 404, the CPU 110 calculates the Mahalanobis distance D1 using the data of the test result read in step 402. Specifically, the CPU 110 calculates the Mahalanobis distance using the data of the test result corresponding to the parameter used for calculating the normal Mahalanobis distance. For example, if the normal Mahalanobis distance is obtained for two parameters, the Mahalanobis distance is calculated by the above equation (1). FIG. 5 shows the measurement result 230 and the corresponding distance D1 of Mahalanobis.

  In step 406, the CPU 110 determines whether or not the Mahalanobis distance D1 calculated in step 404 is less than or equal to the normal Mahalanobis distance D0 read in step 400. If it is determined that D1 ≦ D0, the control proceeds to step 408. Otherwise (D1> D0), control proceeds to step 410.

  In step 408, the CPU 110 determines that the protection relay 202 to be tested is normal (good state), and stores information specifying the determination in the storage unit 112. For example, the CPU 110 stores “0” in the storage unit 112.

  In step 410, the CPU 110 determines that the protection relay 202 to be tested may be abnormal (defective), and stores information specifying the determination in the storage unit 112. For example, the CPU 110 stores “1” in the storage unit 112.

  As described above, the state of the protection relay 202 is determined from the test result of the protection relay 202, and information indicating the determination result is stored in the storage unit 112. Thereafter, control proceeds to step 318 in FIG.

  In step 318, CPU 110 reads the data stored in storage unit 112 in step 408 or 410, and displays a corresponding message on display unit 118. If the read data is “0”, the CPU 110 displays, for example, “judgment result: no problem”. On the other hand, if the read data is “1”, the CPU 110 displays, for example, “Recommend replacement because there is a tendency for failure (deterioration)” and announces the tendency for deterioration.

  As described above, in the test system 100, the tester does not directly operate the protection relay tester 102 to perform individual tests on the protection relay 202, but only instructs the control device 104 to execute the test. The test of 202 is executed, and the result of the pass / fail judgment is displayed on the display unit 118. Therefore, the burden on the tester can be reduced, and the tester can objectively, quickly and accurately determine the quality of the protective relay 202.

  In addition, the tester can be shown the tendency of the protection relay to deteriorate. Therefore, conventionally, when the test result is located at the boundary of the control value, it is possible to prevent the protection relay from being determined to be “good” despite the fact that the protection relay tends to deteriorate.

  Fluctuations in the relay driving voltage of the protective relay affect changes in the operation time of the relay contact output. This voltage fluctuation may be caused by deterioration of an electronic circuit constituting the protection relay. Also, a change in the ambient temperature may affect the deterioration of the electronic circuit constituting the protection relay, and thus affect the operation time fluctuation of the relay contact output. Therefore, as described above, it is preferable to use the relay drive voltage and the ambient temperature of the protection relay as parameters.

  In general, it is conceivable to correct the operation time with a characteristic curve obtained from the "voltage-operation time" characteristic and the "temperature-operation time" characteristic.However, the amount of change is small for a normal protective relay. In addition, acquiring such characteristic data in advance is complicated. On the other hand, by using the relay drive voltage and the ambient temperature as parameters, calculating the Mahalanobis distance as described above, and using the calculated distance as a reference for evaluation, it is possible to easily determine the quality (deterioration tendency) of the protective relay.

  In the above description, the case where the pass / fail of the protection relay is determined only by comparing the magnitude with the distance D0 of one normal Mahalanobis, but the present invention is not limited to this. For example, if the pass data is classified according to its level, and a plurality of normal Mahalanobis distances are obtained using the pass data of each classification, the Mahalanobis distance D1 obtained from the test result is calculated for a plurality of normal times. By comparing with the Mahalanobis distance, it is possible to determine how good the protective relay is.

  In addition, the pass / fail determination process (step 316) in FIG. 3 does not need to use the Mahalanobis distance shown in FIG. The CPU 110 may execute, for example, a process illustrated in FIG. 6 as the pass / fail determination process.

  The flowchart of FIG. 6 is different from the flowchart of FIG. 4 in that steps 400, 404, and 406 are replaced by steps 420, 422, and 424, respectively. In FIG. 6, the processes in the steps denoted by the same reference numerals as those in FIG. 4 are the same as those in FIG. Hereinafter, steps that are different from FIG. 4 will be mainly described without repeating the repeated description.

  In step 420, CPU 110 reads average value μ and standard deviation σ from storage section 112 as reference values for determination. The average value μ and the standard deviation σ are calculated for each protection relay element using, for example, all the passing data used for calculating the normal Mahalanobis distance. The average value μ and the standard deviation σ of all the pass data are calculated in advance by a known method using, for example, the operation time, and stored in the storage unit 112. Similarly, an average value μ and a standard deviation σ are calculated in advance for other protection relay elements, for example, a relay drive voltage, and stored in the storage unit 112.

  Thereafter, CPU 110 reads test result data d stored in storage unit 112 in step 310 of FIG. 3 (step 402), and in step 420, CPU 110 determines the average value of the protective relay element corresponding to test result data d. Using μ, a difference (hereinafter, referred to as a deviation) Δ from the average value μ of the test result data d is calculated (Δ = d−μ).

  In step 424, the CPU 110 determines whether or not the absolute value of the deviation Δ calculated in step 422 is equal to or less than a value (a · σ) of the standard deviation σ of the protection relay element corresponding to the test result data d. I do. If it is determined that | Δ | ≦ a · σ, the control proceeds to step 408. Otherwise (| Δ |> a · σ), control proceeds to step 410. The value of the coefficient a is, for example, 0.5, and may be stored in the storage unit 112 in advance.

  Then, by executing step 408 or 410, data “0” or “1” representing normal (good state) or abnormal (bad state) is stored in the storage unit 112, respectively. Therefore, if the test result data d falls within the range of μ ± 0.5σ (a range including about 38% of all total data) in the normal distribution of the average value μ and the standard deviation σ, “Judgment: Problem "None" is displayed on the display unit 118, and if the value is out of the range of ± 0.5 sigma, an announcement such as "Recommend replacement because there is a tendency for failure (deterioration)" may be displayed on the display unit 118. it can.

  Thus, when the test result is located at the boundary of the control value, it can be prevented that the protection relay is determined to be “good” despite the fact that the protection relay tends to deteriorate.

  Note that the value of the coefficient a is not limited to 0.5. For example, even if a = 1 (approximately 68% of the total data is included in the range of μ ± σ), a = 2 (the range of μ ± 2σ) It may be about 95% of the total tabulated data) or a = 3 (about 99.7% of the total tabulated data is included in the range of μ ± 3σ). The coefficient a may be in the range of 0.1 ≦ a ≦ 3.

  It is also preferable to change the value of the coefficient a according to the type of the protection relay to be tested. For example, when the protection relay to be tested is a digital protection relay, it is preferable to use a smaller value for the coefficient a, considering that the digital type has a small variation in characteristics.

  Further, the pass / fail judgment processing (step 316) in FIG. 3 may not be the one shown in FIGS. For example, conventionally, when the control value is A ± 5% (A is a numerical value corresponding to the protective relay element), for example, A ± 3% is set as a stricter range (safer range). Is also good. In this case, the pass / fail judgment is made by judging whether or not the value of the test result falls within the range of A ± 3%. If it is within the range of A ± 3%, it is determined to be normal, and for example, an announcement “judgment: no problem” is displayed on the display unit 118. If it does not fall within the range of A ± 3%, it is determined that there is a possibility of abnormality, and for example, an announcement “recommended replacement because of a tendency to failure (deterioration)” is displayed on the display unit 118.

  When test results of a plurality of protective relay elements (for example, operation time and relay drive voltage) are used, for example, it is determined whether all test results are within a stricter set range than before. I just need. Only when all the test results fall within the set range is determined to be normal, and when at least one test result does not fall within the set range, it is determined that there is a possibility of abnormality.

  As described above, by determining the acceptability using a range that is stricter than the conventional control value, when the test result is located at the boundary of the conventional control value, the test result is determined to be “good” despite the tendency of deterioration. The determination can be prevented.

(First Modification)
In the configuration shown in FIGS. 1 and 2, the case where the protection relay tester 102 acquires the operation signal from the protection relay 202 by wire has been described, but the present invention is not limited to this. The protection relay tester 102 may acquire the operation signal from the protection relay 202 via a device having a wireless communication function (hereinafter, also referred to as a wireless module).

  Referring to FIG. 7, a test system 150 according to the first modification includes a protection relay tester 102, a control device 104, a temperature sensor 106, a first wireless module 152, and a second wireless module 154. The configuration in FIG. 7 is obtained by adding a first wireless module 152 and a second wireless module 154 to the configuration illustrated in FIG. The protection relay tester 102, the control device 104, and the temperature sensor 106 have the functions described above with reference to FIGS. In this modification, the control device 104 has a wireless communication function in addition to the above-described functions.

  In this modification, an operation signal generated as a result of the operation of the protection relay 202 supplied with the test signal (relay ON / OFF) is not directly input to the protection relay tester 102 but is transmitted to the first wireless module 152. Is entered. The first wireless module 152 has a function of performing wireless communication with the second wireless module 154 and a function of performing A / D conversion of an input signal. That is, the first wireless module 152 converts the input analog operation signal into digital data by A / D conversion, and transmits the converted data to the second wireless module 154 by wireless communication. Note that the internal relay drive voltage (relay drive voltage) of the protection relay 202 is directly measured by the control device 104, similarly to the configuration shown in FIGS.

  The second wireless module 154 has a function of performing wireless communication with the control device 104 and the first wireless module 152, and a function of performing wired communication with the protection relay tester 102 by using GPIB or RS-232C or the like. The second wireless module 154 receives the data (operation signal) transmitted from the first wireless module 152, and transmits the received data to the protection relay tester 102 by wire.

  Hereinafter, the test of the protection relay by the test system 150 will be described. As described above, the control device 104 configuring the test system 150 performs the processing illustrated in FIG. That is, after acquiring and storing the temperature data from the temperature sensor 106, the control device 104 transmits the test information (the control command and its parameter) to the protection relay tester 102. At this time, the test information is transmitted to the protection relay tester 102 via the second wireless module 154.

  The protection relay tester 102 generates a test signal according to the received test information and supplies the test signal to the protection relay 202. The operation signal output from the protection relay 202 to which the test signal has been supplied is input to the first wireless module 152 and A / D converted by the first wireless module 152 as described above. Sent to module 154. The second wireless module 154 transmits the data (operation signal) received from the first wireless module 152 to the protection relay tester 102 by wire communication. On the other hand, the relay drive voltage is directly measured by the control device 104 as described above.

  The protection relay tester 102 receives data (operation signal) from the second wireless module 154 for a predetermined time and stores the data. The CPU 130 (see FIG. 2) of the protection relay tester 102 reads out the operation signal stored in the storage unit 132, calculates a test result, and transmits the test result to the control device 104. At this time, the transmission of the test result from the protection relay tester 102 to the control device 104 is performed via the second wireless module 154.

  Upon receiving the test result from the protection relay tester 102 and measuring the relay drive voltage, the control device 104 executes a pass / fail determination process (see FIGS. 4 and 6) and presents the result.

  As described above, similarly to the test system 100 shown in FIGS. 1 and 2, the tester can directly operate the protection relay tester 102 in the test system 150 without performing individual tests on the protection relay 202 without using the control device. By simply instructing the execution of the test to the 104, the test of the protection relay 202 is executed and the result of the pass / fail judgment is presented. Therefore, the burden on the tester can be reduced, and the tester can objectively, quickly and accurately determine the quality of the protective relay 202.

(Second Modification)
Further, the configuration shown in FIG. 7 may be changed, for example, as shown in FIG. In the configuration of FIG. 8, the lighting information of the LED disposed on the front surface of the protection relay 202 is transmitted to the protection relay tester 102.

  Referring to FIG. 8, a test system 160 according to the second modified example includes a protection relay tester 102, a control device 104, a temperature sensor 106, a second wireless module 154, an imaging device 162, and a third wireless module 164. The configuration in FIG. 8 is obtained by adding an imaging device 162 to the configuration illustrated in FIG. 7 and replacing the first wireless module 152 with a third wireless module 164. The protection relay tester 102 and the temperature sensor 106 have the functions described above with reference to FIGS. 1 and 2, and the control device 104 has a wireless communication function in addition to the functions described above.

  On the front surface of the protection relay 202, a plurality of LEDs are arranged in an LED arrangement area 212 as shown in FIG. The operation state of the protection relay 202 is displayed by lighting of each LED. In FIG. 9, “A”, “B”, and “C” represent three systems of relays, and “51H” and “51L” represent high-voltage and low-voltage relays for overcurrent protection, respectively, for each system. . When the test signal is input, the LED is turned on according to the state of the relay inside the protection relay 202 according to the test signal. For example, when a test signal for turning on the relay inside the protection relay 202 is gradually changed (increased or decreased) and supplied to the protection relay 202, when a predetermined test signal value is reached, the corresponding LED is turned on. Light. The test signal value when the LED is turned on is stored as a check result of the operation value of the protection relay 202.

  The imaging device 162 takes an image of a region including the LED on the front surface of the protection relay 202 (for example, the imaging region 210 in FIG. 9) as an imaging target at predetermined time intervals (frame rate). The imaging device 162 inputs the captured image to the third wireless module 164. The imaging device 162 is, for example, a digital camera, and outputs a captured image as a predetermined digital video signal (for example, in a format of HDMI (registered trademark), DVI, or the like). The imaging device 162 may output an analog signal.

  Referring to FIG. 10, third wireless module 164 includes CPU 170, storage unit 172, IF unit 176, wireless communication unit 178, and bus 180. The CPU 170 controls the entire third wireless module 164. The storage unit 172 stores data and is, for example, a rewritable nonvolatile semiconductor memory. The storage unit 172 stores a program executed by the CPU 170 for controlling each unit. The storage unit 172 stores the image data received from the imaging device 162. Further, the storage unit 172 stores a plurality of image data to be compared with the image data received from the imaging device 162 as a database 174, as described later. Data exchange between the units is performed via a bus 180.

  The IF unit 176 is an interface with the imaging device 162, takes in a video signal input from the imaging device 162, and stores the video signal in the storage unit 172. If the input signal is digital data, the IF unit 176 stores the input signal as it is in the storage unit 172, and if the input signal is an analog signal, converts the input signal into digital data using an A / D converter and stores the digital data in the storage unit 172. The wireless communication unit 178 has a function of performing wireless communication with the second wireless module 154.

  The second wireless module 154 has a function of performing wireless communication with the control device 104 and the third wireless module 164, and a function of performing wired communication with the protection relay tester 102 by using GPIB or RS-232C or the like. The second wireless module 154 receives the data transmitted from the third wireless module 164 and transmits the received data to the protection relay tester 102 by wire.

  Hereinafter, the test of the protection relay by the test system 160 will be described. As described above, the control device 104 configuring the test system 160 executes the processing illustrated in FIG. That is, after acquiring and storing the temperature data from the temperature sensor 106, the control device 104 transmits the test information (the control command and its parameter) to the protection relay tester 102. At this time, the test information is transmitted to the protection relay tester 102 via the second wireless module 154.

  The protection relay tester 102 supplies the test signal to the protection relay 202 while gradually changing (increase or decrease) the value of the test signal according to the received test information. The result of the operation of the protection relay 202 supplied with the test signal is indicated by the LED on the front face of the protection relay 202 as described above. As described above, the imaging device 162 captures an image of a predetermined area including an LED at predetermined time intervals, and outputs image data of the captured image. The output (image data) of the imaging device 162 is input to the third wireless module 164.

  Referring to FIG. 10, images input to third wireless module 164 are stored in storage unit 172 in a time series. The CPU 170 compares the images stored in the storage unit 172 in time series with the images stored in the database 174 in advance, specifies the lit LED, and information indicating the specified LED (hereinafter, lighting information). ) Is stored in the storage unit 172. For example, if the database 174 previously stores an image of an LED lighting pattern obtained by imaging the same region as the imaging region of the imaging device 162 with respect to the protection relay 202, the CPU 170 executes the respective image data received from the imaging device 162. Is read from the storage unit 172, and the degree of similarity with the image of the lighting pattern is evaluated, whereby the lit LED can be specified. The determination of the image similarity can be realized by known image processing. The CPU 170 reads out the lighting information indicating the specified LED from the storage unit 172, and transmits the lighting information to the second wireless module 154 via the wireless communication unit 178.

  The second wireless module 154 transmits the lighting information received from the third wireless module 164 to the protection relay tester 102 by wire communication. When receiving the lighting information from the second wireless module 154, the protection relay tester 102 stops the change (increase or decrease) of the test signal, determines the test signal value at the time of the stop as the operation value, and stores it in the storage unit 132. Remember. The CPU 130 (see FIG. 2) of the protection relay tester 102 reads the operation value stored in the storage unit 132 and transmits the operation value to the control device 104 via the second wireless module 154.

  Upon receiving the test result (operation value), the control device 104 executes a pass / fail determination process (see FIGS. 4 and 6) and presents the result.

  As described above, as in the test system 100 shown in FIGS. 1 and 2, the tester can directly operate the protection relay tester 102 in the test system 160 without performing individual tests on the protection relay 202 without using the control device. By simply instructing the execution of the test to the 104, the test of the protection relay 202 is executed and the result of the pass / fail judgment is presented. Therefore, the burden on the tester can be reduced, and the tester can objectively, quickly and accurately determine the quality of the protective relay 202. In addition, since the test result is obtained as the lighting information of the LED on the front of the protection relay, the test can be performed more easily than when the operation signal of the protection relay is received.

  In the first and second modifications, the case where the output signal (temperature data) of the temperature sensor 106 is transmitted to the control device 104 by wire has been described. However, the output signal of the temperature sensor 106 is transmitted to the control device by wireless communication. 104. For example, in the first modification (see FIG. 7), after the output signal of the temperature sensor 106 is input to the first wireless module 152 and A / D converted, the first wireless module 152 sends the second wireless signal to the control device 104. It may be transmitted wirelessly via the module 154 or directly. Similarly, in the second modification (see FIG. 8), after the output signal of the temperature sensor 106 is input to the third wireless module 164 and A / D converted, the second wireless module 164 sends the second wireless module 164 The wireless transmission may be performed via the wireless module 154 or directly. Further, a wireless module different from the first wireless module 152 and the third wireless module 164 may be provided, and the output signal of the temperature sensor 106 may be wirelessly transmitted to the control device 104.

  In the first and second modifications, the case where the second wireless module 154 is provided separately from the protection relay tester 102 and the control device 104 has been described, but the present invention is not limited to this. For example, the protection relay tester 102 may have a wireless communication function with the first wireless module 152 or the third wireless module 164. In addition, the control device 104 wirelessly communicates with the first wireless module 152 or the third wireless module 164, receives information (operation signal, LED lighting information) of the protection relay 202, and performs wired communication with the protection relay tester 102. May be transmitted.

  Although the case where the control device 104 directly measures the internal relay drive voltage (relay drive voltage) of the protection relay 202 has been described above, the present invention is not limited to this. In the configuration illustrated in FIG. 2, the internal relay drive voltage of the protection relay 202 may be input to the input unit 142 of the protection relay tester 102 and transmitted to the control device 104 via the IF unit 134. Further, in the configuration illustrated in FIG. 7, the internal relay drive voltage of the protection relay 202 may be input to the first wireless module 152 and transmitted to the control device 104 via the second wireless module 154.

  As described above, the present invention has been described by describing the embodiment. However, the above-described embodiment is an exemplification, and the present invention is not limited to the above-described embodiment. The scope of the present invention is shown by each claim of the claims, in consideration of the description of the detailed description of the invention, and all changes within the meaning and range equivalent to the language described therein are described. Including.

100, 150, 160 Test system 102 Protection relay tester 104 Controller 106 Temperature sensor 110, 130, 170 CPU
112, 132, 172 Storage unit 114, 134, 176 IF unit 116, 136 Operation unit 118, 138 Display unit 120, 144, 180 Bus 140 Output unit 142 Input unit 152 First wireless module 154 Second wireless module 162 Imaging device 164 Third wireless module 174 Database 178 Wireless communication unit 200 Switchboard 202 Protective relay 210 Imaging area 212 LED arrangement area 220, 222, 224 Ellipse 230 Measurement result

Claims (5)

A protective relay tester,
A control device for communicating with the protection relay tester,
A temperature sensor that measures the temperature of the environment in which the protective relay to be tested is installed,
The protection relay tester,
Under control of the control device, an output unit that supplies a predetermined test signal to the protection relay,
With the operation of the protection relay by the supply of the test signal, input means for acquiring an operation signal output from the protection relay,
From the operation signal, computing means for calculating the operation time of the protection relay,
Communication means for transmitting the operation time to the control device,
The control device includes:
The operating time, the temperature measured by the temperature sensor, and receiving means for receiving a relay drive voltage generated by power supply to the protection relay,
A determining unit that calculates a value to be evaluated from the operation time, the relay drive voltage, and the measured temperature, and compares the value to be evaluated with a predetermined reference value to determine a state of the protection relay. A test system. The reference value is a Mahalanobis distance determined from a set of samples including an operation time and a relay driving voltage, which are test results of a normally operating protection relay, and a measurement temperature of an environment in which the protection relay is installed. ,
The evaluated value is a distance of the Mahalanobis calculated from the set of the operation time received by the receiving unit, the relay drive voltage and the measured temperature,
The determining means includes:
If the evaluated value is equal to or less than the reference value, the protection relay to be tested is determined to be normal,
The test system according to claim 1, wherein if the evaluated value is larger than the reference value, it is determined that the protection relay to be tested has a possibility of abnormality. The reference value is a product of a standard deviation and a predetermined coefficient calculated from a set of one sample of the operation time and the relay drive voltage, which are test results of the normally operating protection relay,
The predetermined coefficient is a value of 0.1 or more and 3 or less,
The evaluated value is an average value calculated from the one set of samples, and one of the operation time and the relay drive voltage received by the receiving unit, and calculates the standard deviation. Difference from the value corresponding to the set
The determining means includes:
If the absolute value of the difference is equal to or less than the reference value, it is determined that the protection relay to be tested is normal,
The test system according to claim 1, wherein if the absolute value of the difference is larger than the reference value, it is determined that the protection relay to be tested has a possibility of abnormality. A protective relay tester,
A control device for communicating with the protection relay tester,
A temperature sensor for measuring the temperature of the environment where the protective relay to be tested is installed,
An imaging device for imaging an area including an LED provided in the protection relay;
A lighting information generation device that detects lighting of the LED from an image captured by the imaging device and generates lighting information,
The protection relay tester,
Under control of the control device, a predetermined test signal to the protection relay, output means for supplying the test signal by gradually increasing or decreasing the value of the test signal,
From the lighting information generation device, an acquisition unit that acquires the lighting information of the LED that is lit according to the operation of the protection relay by the supply of the test signal,
When the lighting information is obtained by the obtaining unit, a determining unit that determines a value of the test signal supplied from the output unit as an operation value of the protection relay,
Communication means for transmitting the operation value to the control device,
The control device includes:
Receiving means for receiving the operation value, and the temperature measured by the temperature sensor,
Calculating the evaluated value from the operating value and the measured temperature, by comparing the evaluated value and a predetermined reference value, having a determination unit that determines the state of the protection relay, Testing system. A method of testing a protective relay,
Obtaining a measured temperature of the environment in which the protective relay is installed,
Controlling a protection relay tester by a control device to supply a predetermined test signal to the protection relay;
By the protection relay tester, with the operation of the protection relay by the supply of the test signal, obtaining an operation signal output from the protection relay,
By the protection relay tester, from the operation signal, the operation time of the protection relay and a step of calculating a relay drive voltage,
Calculating a value to be evaluated from the operation time, the relay drive voltage and the measured temperature by the control device;
Determining a state of the protection relay by comparing the evaluated value with a predetermined reference value by the control device.

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