Data display method

Abstract

To provide a data display method which contributes to improving reliability of a protective relay device.SOLUTION: A data display method includes: input processing for inputting data including a direction of a voltage applied between voltage terminals P1 and P2 of a protective relay device 10 in the case where one distribution line in three-phase distribution lines 31, to which the protective relay device 10 is connected, is grounded, and a direction of a current flowing via current terminals C1 and C2 of the protective relay device 10 in the case where the distribution line is grounded; and display processing for displaying on a display device phases of a ground-time zero-phase voltage and a ground-time zero-phase current which are recognized by the protective relay device 10 on the basis of the data.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a method for displaying data about a protective relay device. [Background technology]

[0002] Known technologies relating to protective relay devices are described, for example, in Patent Documents 1 and 2. Patent Document 1 describes that "a development connection diagram of the main circuit of the electric power equipment, the results of automatic calculation of the phases of each part of the development connection diagram, and the phases of the measurement signals of the plurality of instrument transformers are displayed."

[0003] Furthermore, Patent Document 2 describes that "zero-phase power is integrated for a predetermined period, and depending on the positive or negative sign of the obtained integral value, it is determined whether the location of the ground fault is on the power supply side or the load side." [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-176466 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-294806 Summary of the Invention [Problem to be solved by the invention]

[0005] Until now, in the design stage of a protective relay device, designers have shown the vectors of zero-phase sequence voltage and zero-phase sequence current during a ground fault on an exploded wiring diagram or the like, and then determined the correct connection relationship. However, because the concept of ground faults is complex and the process of creating the vectors of zero-phase sequence voltage and zero-phase sequence current during a ground fault is also cumbersome, there is a need for ingenuity to prevent errors during the design stage. Furthermore, if there is a connection error during the testing stage of the protective relay device, the test may not be performed correctly, so there is a need to improve reliability. Patent Documents 1 and 2 do not describe technologies that contribute to improving the reliability of such protective relay devices.

[0006] Therefore, an object of the present disclosure is to provide a data display method that contributes to improving the reliability of protective relay devices. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, the data display method according to the present disclosure includes an input process for inputting data including the direction of the voltage applied between the voltage terminals of the protective relay device when one of the three-phase distribution lines to which the protective relay device is connected has a ground fault, and the direction of the current flowing through the current terminals of the protective relay device when the distribution line has a ground fault, and a display process for displaying on a display device the respective phases of the zero-phase voltage and the zero-phase current at the time of a ground fault recognized by the protective relay device based on the data. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to provide a data display method that contributes to improving the reliability of protective relay devices. [Brief explanation of the drawings]

[0009] [Figure 1A] 1 is a functional block diagram of a protection relay device that is a target of a data display method according to a first embodiment. FIG. [Figure 1B] FIG. 2 is a functional block diagram of a computer that executes the data display method according to the first embodiment. [Figure 2] 3 is an explanatory diagram of voltage vectors and current vectors when a protective relay device is connected to a three-phase distribution line in the data display method according to the first embodiment. FIG. [Figure 3] 10 is an explanatory diagram of a ZVT terminal information list related to a protection relay device in the data display method according to the first embodiment. FIG. [Figure 4] 10 is an explanatory diagram of a ZCT terminal information list related to a protection relay device in the data display method according to the first embodiment. FIG. [Figure 5] 4 is a flowchart showing the processing of a computer when designing a protection relay device in the data display method according to the first embodiment. [Figure 6] 10 is a display example showing voltage and current vectors when the wiring at the time of designing the protective relay device is correct in the data display method according to the first embodiment. [Figure 7] 10 is a display example showing voltage and current vectors in the case where the wiring at the time of designing the protective relay device is incorrect, in the data display method according to the first embodiment. [Figure 8] 10 is an explanatory diagram showing voltage vectors and current vectors during testing of a protective relay device in a data display method according to a second embodiment. FIG. [Figure 9] 10 is a flowchart showing processing during testing of a protection relay device in a data display method according to a second embodiment. [Figure 10] 10 is a display example showing voltage and current vectors when the connection at the time of testing the protective relay device is correct in the data display method according to the second embodiment. [Figure 11] 10 is a display example showing voltage and current vectors when connections are incorrect during testing of a protective relay device in the data display method according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] First Embodiment <Configuration of protective relay device> FIG. 1A is a functional block diagram of a protection relay device 10 that is a target of a data display method according to a first embodiment. The protective relay device 10 is a device for protecting a power system from ground faults. That is, when a ground fault is detected, the protective relay device 10 electrically cuts off the faulty part, thereby suppressing the spread of the effects of the ground fault. Note that a "ground fault" is a phenomenon in which a part of an electric circuit that has a predetermined potential relative to the ground is electrically connected to the ground as an abnormal state.

[0011] Such a protective relay device 10 is connected to the main circuits of a generator (not shown) and a transformer (not shown), as well as to a power transmission line. The main circuit is a three-phase power distribution line connected to the generator and the transformer. By using the protective relay device 10, the generator and the transformer can be protected from damage to their cores and deterioration of the insulation of the electrical circuit even in the event of a ground fault.

[0012] 1A, the protective relay device 10 includes an abnormality detection unit 11, a CPU 12, a user interface 13, an input unit 14, and an output unit 15. The abnormality detection unit 11 has a function of detecting the occurrence of a ground fault. The CPU 12 loads a program stored in a nonvolatile memory such as a read-only memory (ROM) into a volatile memory such as a random access memory (RAM), and executes predetermined processing.

[0013] The user interface 13 has a function as an input device that accepts input operations by the user, as well as a function as a display device that displays the calculation results of the CPU 12 in a predetermined manner. The input operations by the user are performed, for example, by operating a predetermined button or touch panel of the protection relay device 10. The display function of the user interface 13 is performed, for example, by using a display.

[0014] The input unit 14 is a terminal to which a zero-phase sequence voltage or a zero-phase sequence current is input in the event of a ground fault. The output unit 15 outputs a predetermined detection signal to an external device (not shown) when a ground fault is detected by the abnormality detection unit 11. The zero-phase sequence voltage and the zero-phase sequence current will be described later.

[0015] FIG. 1B is a functional block diagram of a computer 20 that executes the data display method according to the first embodiment. The computer 20 shown in Fig. 1B is a device used for circuit design of the protection relay device 10 (see Fig. 1A), and includes a main body 21, an input device 22, and a display device 23. The main body 21 includes a storage unit 21a, a processing unit 21b, and an interface 21c. The storage unit 21a includes a non-volatile memory such as a ROM and a volatile memory such as a RAM. The storage unit 21a stores predetermined programs and also software used for circuit design of the protection relay device 10 (see Fig. 1A).

[0016] The processing unit 21b reads out a program from the storage unit 21a, develops it, and executes a predetermined process. The interface 21c converts data input by operating the input device 22 into a predetermined format and outputs the converted data to the processing unit 21b. The interface 21c also outputs the calculation results of the processing unit 21b to the display device 23 as image data.

[0017] The input device 22 is, for example, a keyboard or a mouse, and is used when a user inputs data. The display device 23 is, for example, a display, and is used to display the calculation results of the processing unit 21b. In the design stage of the protective relay device 10 (see FIG. 1A), for example, a circuit design is performed using an exploded schematic diagram (not shown). Here, the "exploded schematic diagram" is a diagram that shows the control of equipment and the like expanded based on its sequential operations.

[0018] FIG. 2 is an explanatory diagram of voltage vectors and current vectors when the protective relay device 10 is connected to a three-phase distribution line 31. Of the multiple frames shown in Fig. 2, the dashed frames (a), (A), (C), and (D) respectively indicate data set by operations via the input device 22 (see Fig. 1B) of the computer 20 (see Fig. 1B) during design of the protective relay device 10. Furthermore, the solid frames (B), (E), (F), (G), and (H) shown in Fig. 2 respectively indicate the results of calculations performed by the processing unit 21b (see Fig. 1B) of the computer 20 (see Fig. 1B) based on data set by the user. In Fig. 2, the protective relay device 10 is referred to as a "protective relay."

[0019] The three-phase distribution line 31 shown in Fig. 2 is an R-phase, S-phase, and T-phase power line, and is included in a main circuit 30 of a generator (not shown) and a transformer (not shown). The protective relay device 10 shown in Fig. 2 includes a ZVT10v (Zero-phase Voltage Transformer) and a ZCT10c (Zero-phase Current Transformer), and also includes a DGR (Directional Ground Relay), although not shown.

[0020] The ZVT10v is a zero-phase transformer for detecting the zero-phase voltage of the three-phase distribution line 31. The "zero-phase voltage" is the voltage to ground at the neutral point of the three-phase distribution line 31. The operating principle of the ZVT10v is to detect the zero-phase voltage by dividing the respective voltages to ground of the R, S, and T phases of the three-phase distribution line 31 using capacitors (not shown), transforming them, and then combining the resulting voltages.

[0021] The ZCT 10c is a zero-phase current transformer for detecting the zero-phase current of the three-phase distribution line 31. The "zero-phase current" refers to a ground current at the neutral point of the three-phase distribution line 31. In the ZCT 10c, the three-phase distribution line 31 is inserted through an annular core (not shown) around which a secondary winding 103c is wound, and the three-phase current is magnetically coupled. The ZCT 10c detects the zero-phase current flowing through the secondary winding 103c. For example, when the three-phase distribution line 31 is in a three-phase balanced state, the zero-phase voltage and zero-phase current are zero. When a line-to-ground fault or the like occurs in the three-phase distribution line 31, the three-phase is unbalanced, and a predetermined magnitude of zero-phase voltage and zero-phase current is generated.

[0022] The DGR (not shown) is a directional ground relay that determines whether a ground fault has occurred based on the zero-phase sequence voltage detected by the ZVT 10v and the zero-phase sequence current detected by the ZCT 10c. The DGR also has the function of determining whether a ground fault has occurred on the power supply side or the load side, as viewed from the installation location of the protective relay device 10. This DGR, together with the ZVT 10v and ZCT 10c, functions as the abnormality detection unit 11 (see FIG. 1A).

[0023] As shown in Fig. 2, the ZVT 10v has a pair of voltage terminals P1 and P2. The voltage terminals P1 and P2 are terminals for applying the zero-phase voltage of the three-phase distribution line 31 to the ZVT 10v. In Fig. 2, the voltage terminals P1 and P2 appear not to be connected to each other, but in reality, the voltage terminals P1 and P2 are electrically connected via a predetermined electric circuit (not shown) of the ZVT 10v.

[0024] 2 are a pair of terminals provided on the protection relay panel 40. The secondary wiring of the ZVT connection is connected to the voltage terminals P1 and P2 of the ZVT 10v via the voltage test terminals 41v and 42v of the protection relay panel 40. The voltage test terminals 41v and 42v are used not only when testing the protection relay device 10 but also during normal use.

[0025] As shown in Fig. 2, the ZCT 10c has a pair of current terminals C1 and C2. The current terminals C1 and C2 are terminals for passing the zero-phase current of the three-phase distribution line 31 through the ZCT 10c. In Fig. 2, the current terminals C1 and C2 appear to be disconnected from each other, but in reality, the current terminals C1 and C2 are electrically connected via a predetermined electric circuit (not shown) of the ZCT 10c.

[0026] 2 are a pair of terminals provided on the protection relay panel 50. The wiring of the ZCT connection is connected to the current terminals C1 and C2 of the ZCT 10c via the current test terminals 51c and 52c of the protection relay panel 50. The current test terminals 51c and 52c are used not only when testing the protection relay device 10 but also during normal use. The two protection relay panels 40 and 50 may be integrated.

[0027] 2 includes (a) main circuit power factor, (A) main circuit voltage, (B) main circuit current, (E) T-phase ground fault zero-phase voltage, and (F) T-phase ground fault zero-phase current. (a) Main circuit power factor is the power factor in the three-phase distribution line 31 of the main circuit 30, and is set by operation via the input device 22 (see FIG. 1B) of the computer 20 (see FIG. 1B) when the protective relay device 10 is designed.

[0028] (A) The voltage of the main circuit is the voltage vector of each of the R-phase, S-phase, and T-phase in the three-phase distribution line 31 of the main circuit 30, and is set by operation via the input device 22 (see FIG. 1B) when designing the protective relay device 10. As shown in FIG. 2, the voltage vector V of the R-phase R and the S-phase voltage vector V S and the T-phase voltage vector V T and are set at 120° intervals. For example, if a user wants to check the zero-phase voltage and current when a single-phase ground fault occurs in the T phase, the user selects the T phase from the three phases. As shown in Figure 2 (A), the voltage vector V of the T phase selected by the user is Tis shown as a horizontal arrow (towards the left on the paper). Note that instead of the T phase, the user can also select the R phase or the S phase.

[0029] (B) Main circuit current indicates the current vectors of the R-phase, S-phase, and T-phase in the three-phase distribution line 31 of the main circuit 30. The phases of these current vectors are calculated by the processing unit 21b (see FIG. 1B) of the computer 20 (see FIG. 1B) based on the (a) main circuit power factor θ enclosed in a dashed line and (A) main circuit voltage.

[0030] In FIG. 2, vectors that are oriented in the same direction on the paper are considered to be in phase with each other. For example, the T-phase vector V T and the T-phase current vector I T and are in phase (same for R and S phases). (E) Zero-phase sequence voltage during T-phase ground fault shown in Figure 2 is the vector of the zero-phase sequence voltage when a single line ground fault occurs in T-phase. Also, (F) Zero-phase sequence current during T-phase ground fault is the vector of the zero-phase sequence current when a single line ground fault occurs in T-phase.

[0031] The voltage direction recognized by the (C) protective relay is the voltage direction recognized by the CPU 12 (see FIG. 1A) of the protective relay device 10 (specifically, the ZVT 10v), and is set during design by operation via the input device 22 (see FIG. 1B). In the example of FIG. 2, the voltage direction recognized by the (C) protective relay is set to the direction from voltage terminal P1 to voltage terminal P2. Specifically, when a line-to-ground fault occurs in the T-phase and the voltage of the T-phase is positive, the protective relay device 10 is designed to recognize that voltage is being applied in the direction from voltage terminal P1 to voltage terminal P2.

[0032] The direction of current recognized by the (D) protective relay is the direction of current recognized by the CPU 12 (see FIG. 1A) of the protective relay device 10 (specifically, the ZCT 10c), and is set during design by operation via the input device 22 (see FIG. 1B). In the example of FIG. 2, the direction of current recognized by the (D) protective relay is set to the direction from current terminal C2 to current terminal C1. Specifically, when a line-to-ground fault occurs in the T-phase and the current in the T-phase is positive, the protective relay device 10 is designed to recognize that the current flows from current terminal C2 to current terminal C1.

[0033] The "voltage and current vectors recognized by the protective relay" shown in Figure 2 are voltage and current vectors that are recognized (i.e., used in the calculation) when the CPU 12 (see Figure 1A) of the protective relay device 10 (ZVT 10v or ZCT 10c) calculates the voltage and current phases during a ground fault. As shown in Figure 2, the information on the "voltage and current vectors recognized by the protective relay" includes the (G) T-phase ground fault zero-phase voltage and the (H) T-phase ground fault zero-phase current.

[0034] (G) The zero-phase sequence voltage at the time of a T-phase ground fault is a vector of the zero-phase sequence voltage recognized by the protective relay device 10 (specifically, the ZVT 10v) when a single-phase ground fault of the T-phase occurs. Also, (H) the zero-phase sequence current at the time of a T-phase ground fault is a vector of the zero-phase sequence current recognized by the protective relay device 10 (specifically, the ZCT 10c) when a single-phase ground fault of the T-phase occurs.

[0035] For example, when a ground fault occurs in a power system, the zero-phase sequence voltage and the zero-phase sequence current are normally in opposite phases. However, in the protective relay device 10, since the reference phase is set to be in opposite phase to the zero-phase sequence voltage, the zero-phase sequence voltage and the zero-phase sequence current are recognized as being in the same phase. Therefore, when the protective relay device 10 is designed, the protective relay device 10 is designed so that it recognizes the ground-fault zero-phase sequence voltage and the ground-fault zero-phase sequence current as being in the same phase even when the ground-fault zero-phase sequence voltage and the ground-fault zero-phase sequence current are actually in opposite phase. In order to prevent design errors due to human error in this regard, in the first embodiment, a predetermined display screen (see FIGS. 6 and 7) is presented to the user during design.

[0036] FIG. 3 is an explanatory diagram of the ZVT terminal information list 61 related to the protective relay device. The ZVT terminal information list 61 shown in Fig. 3 is a data table in which the connection patterns of the ZVT10v (see Fig. 2), the calculation formulas, and the angles for tilting the reference phase are associated with each other, and is set in advance. In the example of Fig. 3, "odd number connection" and "even number connection" are provided as connection patterns.

[0037] Here, "odd connection" means a connection in which, for example, when a line-to-ground fault occurs in the T phase and the T phase voltage is positive, a voltage is applied from voltage terminal P1 (see FIG. 2) to voltage terminal P2 (see FIG. 2). Also, "even connection" means a connection in which, when a line-to-ground fault occurs in the T phase and the T phase voltage is positive, a voltage is applied from voltage terminal P2 (see FIG. 2) to voltage terminal P1 (see FIG. 2).

[0038] As shown in Fig. 3, as a calculation formula for rotating the reference phase of a voltage vector, ei(0) is associated with odd connections, and ei(-π) is associated with even connections. Mathematically, "e" represents the base of the natural logarithm, and "i" represents the imaginary unit, but in the arithmetic processing of the processing unit 21b (see Fig. 1B), "ei(θ)" is used as an operator for rotating a predetermined vector by the angle θ.

[0039] In the example of Figure 3, in the case of odd-numbered connections, the reference phase of the voltage vector is rotated by 0° (i.e., the reference phase is maintained) based on the calculation formula ei(0). In the case of even-numbered connections, the voltage vector is rotated by -180° (i.e., the voltage vector is reversed) based on the calculation formula ei(-π). Note that the "reference phase" in the ZVT terminal information list 61 refers to the phase of the zero-phase sequence voltage during earth fault of the R-phase, S-phase, or T-phase selected by the user (for example, the T-phase), and corresponds to the (E) T-phase zero-phase sequence voltage during earth fault in Figure 2.

[0040] FIG. 4 is an explanatory diagram of the ZCT terminal information list 62 related to the protective relay device. The ZCT terminal information list 62 shown in Fig. 4 is a data table in which the connection patterns of the ZCT 10c (see Fig. 2), the calculation formulas, and the angles at which the reference phase is tilted are associated with each other, and is set in advance. In the example of Fig. 4, "odd connection" and "even connection" are provided as connection patterns.

[0041] Here, "odd connection" means a connection in which, for example, when a line-to-ground fault occurs in the T phase and the T phase current is positive, current flows from current terminal C1 (see FIG. 2) to current terminal C2 (see FIG. 2). Also, "even connection" means a connection in which, when a line-to-ground fault occurs in the T phase and the T phase current is positive, current flows from current terminal C2 (see FIG. 2) to current terminal C1 (see FIG. 2).

[0042] In the example of Figure 4, in the case of odd-numbered connections, the reference phase of the current vector is rotated by 0° (i.e., the reference phase is maintained) based on the calculation formula ei(0). In the case of even-numbered connections, the current vector is rotated by -180° (i.e., the current vector is reversed) based on the calculation formula ei(-π). Note that the "reference phase" in the ZCT terminal information list 62 refers to the phase of the zero-phase current during an earth fault selected by the user from the R, S, and T phases (for example, the T phase), and corresponds to the (F) T-phase zero-phase current during an earth fault in Figure 2.

[0043] FIG. 5 is a flowchart showing the processing of a computer during the design of a protective relay device (see also FIG. 1B as appropriate). In step S101, the processing unit 21b of the computer 20 receives input of a schematic diagram (not shown). As described above, the schematic diagram is a diagram in which the control of devices and the like are expanded based on their sequential operations. The schematic diagram includes predetermined symbols and characters indicating each electronic component of the protective relay device 10 (see FIG. 2) in addition to the main circuit 30 (see FIG. 2).

[0044] In step S102, the processing unit 21b receives inputs such as (a) the main circuit power factor θ. That is, the processing unit 21b receives inputs of the main circuit power factor θ and the phase relationship between the voltages on the primary and secondary sides of the protective relay device 10 based on the user's operation of the input device 22. In the example of Fig. 2, (a) the main circuit power factor θ is set to 1 (that is, the AC voltage and the AC current are in phase).

[0045] In step S103, the processing unit 21b receives an input of the voltage vector of the (A) main circuit. In the example of FIG. 2, the voltage vector of the (A) main circuit is the voltage vector V R ,V S ,V T is set.

[0046] In step S104, the processing unit 21b accepts a selection of (C) ZVT wiring information. Specifically, the processing unit 21b accepts a selection input of (C) the direction of voltage recognized by the protective relay (see FIG. 2) as the ZVT wiring information based on a user's operation of the input device 22. In the example of FIG. 2, the direction from the voltage terminal P1 to the voltage terminal P2 is set as the direction of voltage recognized by the (C) protective relay, and therefore "odd connection" is selected in the ZVT terminal information list 61 (see FIG. 3).

[0047] In step S105, processing unit 21b accepts the selection of (D) ZCT wiring information. Specifically, processing unit 21b accepts the selection input of (D) the direction of current recognized by the protective relay (see FIG. 2) as the ZCT wiring information based on the user's operation of input device 22. In the example of FIG. 2, the direction from current terminal C2 to current terminal C1 is set as the direction of current recognized by (D) the protective relay, and therefore "even connection" is selected in ZCT terminal information list 62 (see FIG. 4). Note that the order of processing for steps S102 to S105 may be changed as appropriate.

[0048] Furthermore, the "data" input in the "input process" (S102 to S105) during the design of the protective relay device 10 includes the following information: That is, the above-mentioned "data" includes information ((a) and (A) in FIG. 2) on the voltage and current of the three-phase distribution line 31 (see FIG. 2) to which the protective relay device 10 (see FIG. 2) is connected, the direction of the voltage applied between the voltage terminals P1 and P2 of the protective relay device 10 when a ground fault occurs in one of the three-phase distribution lines 31 (for example, the T-phase) ((C) in FIG. 2), and the direction of the current flowing through the current terminals C1 and C2 of the protective relay device 10 when a ground fault occurs in the distribution line ((D) in FIG. 2).

[0049] In the above-mentioned "input processing," the user inputs a selection of the wiring pattern when wiring is connected to voltage terminals P1 and P2 as the direction of voltage ((C) in Figure 2) included in the above-mentioned "data," and also a selection of the wiring pattern when wiring is connected to current terminals C1 and C2 as the direction of current ((D) in Figure 2).

[0050] Next, in step S106 of Fig. 5, the processing unit 21b calculates the phase of the T-phase ground-fault zero-phase-sequence voltage based on a predetermined algorithm. That is, the processing unit 21b calculates (E) the T-phase ground-fault zero-phase-sequence voltage (see Fig. 2) that is assumed when a ground fault occurs in the main circuit 30, and also calculates (G) the T-phase ground-fault zero-phase-sequence voltage (see Fig. 2) that is recognized by the protective relay.

[0051] In step S107, the processing unit 21b calculates the phase of the T-phase ground-fault zero-phase current based on a predetermined algorithm. That is, the processing unit 21b calculates (F) the T-phase ground-fault zero-phase current (see FIG. 2) that is assumed when a ground fault occurs in the main circuit 30, and also calculates (H) the T-phase ground-fault zero-phase current (see FIG. 2) that is recognized by the protective relay.

[0052] In step S108, the processing unit 21b displays the calculation results on the developed connection diagram. That is, the processing unit 21b displays the T-phase ground fault zero-phase voltage ((E) and (G) in FIG. 2) and the T-phase ground fault zero-phase current ((F) and (H) in FIG. 2), which are the calculation results of steps S107 and S108, on the developed connection diagram.

[0053] In this way, the processing unit 21b performs a "display process" (S108) that causes the display device 23 (see FIG. 2) to display the phases of the ground-fault zero-phase-sequence voltage ((G) in FIG. 2) and the ground-fault zero-phase-sequence current ((H) in FIG. 2) recognized by the protective relay device 10, based on the "data" including (a), (A), (C), and (D) in FIG. 2. Such a "display process" is performed at the time of designing the protective relay device 10, based on the "data" input in the above-mentioned "input process."

[0054] Furthermore, in the "display process" described above, the processing unit 21b causes the display device 23 (see FIG. 2) to display the vectors of the ground-fault zero-phase-sequence voltage ((G) in FIG. 2) and the ground-fault zero-phase-sequence current ((H) in FIG. 2) recognized by the protective relay device 10 based on predetermined calculation formulas (see FIGS. 3 and 4) corresponding to each wiring pattern. Specific methods for displaying the T-phase ground-fault zero-phase-sequence voltage and the T-phase ground-fault zero-phase-sequence current will be described later. After performing the process of step S108, the processing unit 21b ends the series of processes (END).

[0055] Next, we will explain the algorithm of zero-phase sequence vector conversion when the processing unit 21b calculates the phase of the T-phase ground fault zero-phase sequence voltage (S106) and the T-phase ground fault zero-phase sequence current (S107). First, the processing unit 21b calculates the current vector (FIG. 2(B)) of the main circuit 30 based on the following equation (1) using the main circuit power factor θ (FIG. 2(a)) input in step S102 and the voltage vector (FIG. 2(A)) of the main circuit 30 input in step S103. "A" and "B" in equation (1) represent predetermined physical quantities (including vectors) corresponding to the alphabets in parentheses in Figure 2. The same applies to equations (2) to (7) described later. "ei" in equation (1) is a rotation operator. For example, ei(π) represents the rotation of a predetermined vector by 180°.

[0056] B = A × ei(arccos(θ)) (1)

[0057] In the case of Figure 2, (a) the main circuit power factor θ is set to 1, so arccos(1) = 0, and the rotation angle of the voltage from the reference phase is 0°. As a result, (A) the voltage of the main circuit and (B) the current of the main circuit are in phase.

[0058] Next, the processing unit 21b reads out data corresponding to the ZVT connection information selected in step S104 from the ZVT terminal information list 61 (see FIG. 3), and identifies the voltage direction ((C) in FIG. 2) recognized by the protection relay device 10. In the example of FIG. 2, the voltage direction is set from voltage terminal P1 to voltage terminal P2, resulting in an odd-numbered connection. Furthermore, the processing unit 21b reads out data corresponding to the ZCT connection information selected in step S105 from the ZCT terminal information list 62 (see FIG. 4), and identifies the direction of the current recognized by the protective relay device 10 ((D) in FIG. 2). In the example of FIG. 2, the current is connected so that the direction of the current is from the current terminal C2 to the current terminal C1, which results in an even number connection.

[0059] There are three types of ground fault patterns in the main circuit 30: an R-phase ground fault, an S-phase ground fault, and a T-phase ground fault. In all cases, the calculation results of the zero-phase voltage and the zero-phase current are the same. In the example of Fig. 2, the T-phase ground fault-time zero-phase voltage (Fig. 2(E)) and the T-phase ground fault-time zero-phase current (Fig. 2(F)) are calculated when a T-phase ground fault occurs. If the T-phase component of the voltage (Fig. 2(A)) of the main circuit 30 is "AT", the T-phase ground fault-time zero-phase voltage (Fig. 2(E)) is expressed by the following equation (2).

[0060] E = AT × ei(-π) (2)

[0061] That is, the vector direction of the zero-phase sequence voltage ((E) in FIG. 2) when the T-phase is grounded is opposite to the vector direction of the T-phase component of the voltage ((A) in FIG. 2) of the main circuit 30. In addition, the zero-phase sequence current ((F) in FIG. 2) when the T-phase is grounded is expressed by the following equation (3).

[0062] F = E × ei(-π) (3)

[0063] In other words, the vector direction of the T-phase ground fault zero-phase sequence current (FIG. 2(F)) is opposite to (the phase is shifted by -π from) the vector direction of the T-phase ground fault zero-phase sequence voltage (FIG. 2(E)). As a result, the vector direction of the T-phase ground fault zero-phase sequence current (FIG. 2(F)) becomes the same as the vector direction of the T-phase component of the voltage (FIG. 2(A)) of the main circuit 30. The algorithm for calculating the T-phase ground fault zero-phase sequence voltage and the T-phase ground fault zero-phase sequence current is set based on the symmetric coordinate method.

[0064] Furthermore, when an odd-numbered connection (a connection in which the voltage flows from voltage terminal P1 to voltage terminal P2) is set in the ZVT 10v, the calculation formula is "ei(0)" in the ZVT terminal information list 61 (see FIG. 3). Therefore, the zero-phase sequence voltage ((G) in FIG. 2) recognized by the protective relay device 10 when the T-phase is grounded is calculated based on the following formula (4).

[0065] G = E × ei(0) (4)

[0066] For example, as shown in (C) of Figure 2, when the connection relationship of ZVT 10v is odd-numbered, the vector direction of the zero-phase sequence voltage ((G) of Figure 2) recognized by the protective relay device 10 when a T-phase ground fault occurs is the same as the vector direction of the zero-phase sequence voltage ((E) of Figure 2) of the main circuit 30 when a T-phase ground fault occurs.

[0067] On the other hand, when an even connection (a connection in which the voltage flows from voltage terminal P2 to voltage terminal P1) is set in ZVT 10v, the calculation formula is "ei(-π)" in the ZVT terminal information list 61 (see Figure 3), so the zero-phase voltage ((G) in Figure 2) at the time of a T-phase ground fault recognized by the protective relay device 10 is calculated based on the following formula (5).

[0068] G = E × ei(-π) (5)

[0069] As a result, when the connection relationship of ZVT10v is an even connection, although not shown in the figure, the direction of the vector of the zero-phase sequence voltage when a T-phase ground fault occurs recognized by the protective relay device 10 is opposite to the direction of the vector of the zero-phase sequence voltage when a T-phase ground fault occurs in the main circuit 30.

[0070] Furthermore, when an odd-numbered connection (a connection in which the current flows from the current terminal C1 to the current terminal C2) is set in the ZCT 10c, the calculation formula is "ei(0)" in the ZCT terminal information list 62 (see Figure 4), and therefore the zero-phase current ((H) in Figure 2) at the time of a T-phase ground fault recognized by the protective relay device 10 is calculated based on the following formula (6).

[0071] H = F × ei(0) (6)

[0072] As a result, when the connection relationship of ZCT 10c is an odd number connection, although not shown in the figure, the direction of the vector of the zero-phase current at the time of a T-phase earth fault recognized by the protective relay device 10 becomes the same as the direction of the vector of the zero-phase current at the time of a T-phase earth fault in the main circuit 30.

[0073] On the other hand, when an even connection (a connection in which the current flows from the current terminal C2 to the current terminal C1) is set in the ZCT 10c, the calculation formula is "ei(-π)" in the ZCT terminal information list 62 (see Figure 4), and therefore the zero-phase current ((H) in Figure 2) at the time of a T-phase ground fault recognized by the protective relay device 10 is calculated based on the following formula (7).

[0074] H=F×ei(-π) (7)

[0075] For example, when the connection relationship of the ZCT 10c is an even connection as shown in Fig. 2, the vector direction of the T-phase earth fault-occurring zero-phase current ((H) in Fig. 2) recognized by the protective relay device 10 is opposite to the vector direction of the T-phase earth fault-occurring zero-phase current ((F) in Fig. 2) of the main circuit 30. In this way, the phases (vector directions) of the earth fault-occurring zero-phase voltage and earth fault-occurring zero-phase current recognized by the protective relay device 10 are parameterized, in addition to the earth fault-occurring zero-phase voltage and earth fault-occurring zero-phase current of the main circuit 30 (see Fig. 2), and a series of processes are automated based on an algorithm that formulates the rules for vector phase conversion.

[0076] Figure 6 is an example of a display showing voltage and current vectors when the wiring of the protective relay device is correct at the time of design. Note that the dashed-line frames (a), (A), (C), and (D) in Fig. 6 correspond one-to-one to the dashed-line frames in Fig. 2. Also, the solid-line frames (B), (E), (F), (G), and (H) in Fig. 6 correspond one-to-one to the solid-line frames in Fig. 2. The display example in Fig. 6 may be displayed in an expansion and connection diagram when designing the protective relay device 10 (see Fig. 2), or may be displayed separately from the expansion and connection diagram.

[0077] When the (a) main circuit power factor, (A) main circuit voltage, (C) voltage direction recognized by the protective relay, and (D) current direction recognized by the protective relay, which are shown in the dashed line frames in FIG. 6, are set by the user's input operation, each piece of information (B), (E), (F), (G), and (H), which are shown in the solid line frames, is calculated by the processing unit 21b (see FIG. 1B), and the calculation results are displayed.

[0078] In the example of FIG. 6, information on the "main circuit voltage and current vectors" and information on the "voltage and current vectors recognized by the protective relay in the event of a ground fault" are displayed side by side. Regarding the "main circuit voltage and current vectors," (a) the main circuit power factor θ is displayed, as well as the following information. That is, as information on the voltage vector of the main circuit 30, (A) the main circuit voltage and (E) the zero-phase sequence voltage in the event of a T-phase ground fault are displayed side by side. In addition, (C) the direction of the voltage recognized by the protective relay is displayed below the (A) main circuit voltage. In the example of FIG. 6, corresponding to the connection relationship in FIG. 2, the fact that there is an "odd number connection (P1 → P2)" is displayed within a dashed frame in (C).

[0079] Furthermore, as information regarding the current vector of the main circuit 30 (see FIG. 2), (B) the current of the main circuit and (F) the zero-phase current at the time of a T-phase ground fault are displayed side by side. Also, (D) the direction of the current recognized by the protective relay is displayed below the (B) main circuit voltage. In the example of FIG. 6, the fact that it is an "even connection (C2 → C1)" is displayed within a dashed frame in (D), corresponding to the connection relationship in FIG. 2.

[0080] Regarding "voltage and current vectors recognized by the protective relay during a ground fault," (G) the zero-phase sequence voltage during a T-phase ground fault is displayed next to (A) the voltage of the main circuit and (E) the zero-phase sequence voltage during a T-phase ground fault. Also, (H) the zero-phase sequence current during a T-phase ground fault is displayed next to (B) the current of the main circuit and (F) the zero-phase sequence current during a T-phase ground fault. In this way, in the "display process" (S108 in FIG. 5), the processing unit 21b (see FIG. 1B) displays the respective phases of the zero-phase sequence voltage during a ground fault ((G) in FIG. 6) and the zero-phase sequence current during a ground fault ((H) in FIG. 6) recognized by the protective relay device 10 as predetermined vectors on the developed connection diagram of the protective relay device 10.

[0081] In the example of FIG. 6, when the (E) T-phase ground fault zero-phase voltage and the (F) T-phase ground fault zero-phase current are actually in opposite phase to each other, the protective relay device 10 (see FIG. 2) calculates the vector V of the (G) T-phase ground fault zero-phase voltage. t and (H) the zero-phase current vector I tAs described above, when a ground fault occurs in the three-phase distribution line 31 (see FIG. 2), the zero-phase voltage and the zero-phase current are in opposite phases, but the processing stage of the protective relay device 10 recognizes the zero-phase voltage and the zero-phase current as being in the same phase.

[0082] In the example of Figure 6, the vector V t and the vector I in (H) t are displayed in the same orientation (toward the right on the paper) on the display screen. This allows the designer to confirm that the wiring of the protective relay device 10 is correct. Specifically, the designer can confirm that it is correct to state in the instruction manual that the voltage terminal P1 in FIG. 2 is connected to the voltage test terminal 41v and the other voltage terminal P2 is connected to the voltage test terminal 42v. Note that the fact that the wiring of the protective relay device 10 is correct may be displayed on the display device 23 (see FIG. 1B).

[0083] Figure 7 shows an example of a display showing voltage and current vectors when the wiring of a protective relay device is incorrect during design. In addition, Fig. 7 shows the zero-phase current vector I t The only difference is that the direction of the arrows is opposite to that in Figure 6 (when the wiring is correct), but otherwise it is the same as Figure 6. Therefore, explanations of parts that overlap with Figure 6 will be omitted.

[0084] For example, if there is an error in the wiring of the ZVT 10v (see FIG. 2) or the ZCT 10c (see FIG. 2) at the design stage, the vector I of the zero-phase current at the time of the T-phase ground fault recognized by the protective relay device 10 will be t As a result, in the protective relay device 10, the direction of the zero-phase sequence voltage vector V t and (H) the zero-phase current vector I tand are recognized as being in opposite phase. In such a case, for example, an error message saying "ground fault connection direction incorrect" (see the bottom right of the page in FIG. 7) is displayed on the display device 23 (see FIG. 1B). This makes it possible to notify the designer that there is an error in the connection of the protective relay device 10.

[0085] In this way, in the "display process" (S108 in FIG. 5), if the phase of the ground-fault-time zero-phase-sequence voltage ((G) in FIG. 7) recognized by the protection relay device 10 differs from the phase of the ground-fault-time zero-phase-sequence current ((H) in FIG. 7) recognized by the protection relay device 10, the processing unit 21b causes the display device 23 (see FIG. 1B) to display a predetermined error message.

[0086] <Effects> According to the first embodiment, when designing the protective relay device 10, the designer can input conditions such as the main circuit power factor θ and the voltage and current of the main circuit 30, thereby displaying vectors of the ground-fault-time zero-phase-sequence voltage and the ground-fault-time zero-phase-sequence current on the display device 23. Displaying the ground-fault-time zero-phase-sequence voltage and the ground-fault-time zero-phase-sequence current as vectors in this way improves visibility for the user. Furthermore, since the designer does not need to create vectors of the zero-phase sequence voltage and the zero-phase sequence current during a ground fault, the time and effort required for circuit design of the protective relay device 10 can be significantly reduced.

[0087] Furthermore, if there is an error in the wiring of the protective relay device 10 at the design stage, a predetermined error message (see FIG. 7) is displayed, thereby preventing wiring errors at the time of design. Therefore, malfunction of the protective relay device 10 can be prevented, and ultimately the reliability of the protective relay device 10 can be improved.

[0088] Second Embodiment The second embodiment differs from the first embodiment in that it is a process performed during testing of the protective relay device 10 (see FIG. 8), but is otherwise similar to the first embodiment (such as the configuration of the protective relay device 10: see FIG. 8). Therefore, only the parts that differ from the first embodiment will be described, and a description of the overlapping parts will be omitted.

[0089] FIG. 8 is an explanatory diagram showing voltage vectors and current vectors during testing of the protective relay device 10 in the data display method according to the second embodiment. Of the multiple frames shown in Fig. 8, the dashed frames (C) and (D) each indicate data set by operation via the user interface 13 (see Fig. 1A) of the protective relaying device 10 when testing the protective relaying device 10. Also, the solid frames (E), (F), (G), (H), (I), and (J) shown in Fig. 8 each indicate the results of calculations performed by the CPU 12 (see Fig. 1A) of the protective relaying device 10 based on data set by the user. Note that the input and display of data related to the protective relaying device 10 may be performed by a computer 20 (see Fig. 1B) connected to the protective relaying device 10.

[0090] As shown in Fig. 8, when testing the protective relay device 10, a pair of voltage terminals P1, P2 of the ZVT 10v are connected to a voltage generator 71 via a protective relay panel 40. In the example of Fig. 8, one voltage terminal P1 is connected to the voltage generator 71 via a voltage test terminal 41v, and the other voltage terminal P2 is connected to the voltage generator 71 via a voltage test terminal 42v. The voltage generator 71 is a device that applies a predetermined AC voltage to the ZVT 10v when a ground fault is assumed.

[0091] Furthermore, when testing the protective relay device 10, a pair of current terminals C1, C2 of the ZCT 10c are connected to a current generator 72 via the protective relay panel 50. In the example of Fig. 8, one current terminal C1 is connected to the current generator 72 via a current test terminal 51c, and the other current terminal C2 is connected to the current generator 72 via a current test terminal 52c. The current generator 72 is a device that supplies a predetermined AC current to the ZCT 10c when a ground fault is assumed.

[0092] 8 shows the (E) T-phase ground fault zero-phase voltage and (F) T-phase ground fault zero-phase current as "voltage and current vectors during test," as well as the (I) input voltage and (J) input current. The (I) input voltage is the vector of the input voltage applied from voltage generator 71 to voltage terminals P1 and P2 of ZVT 10v. The (J) input current is the vector of the input current supplied from current generator 72 to current terminals C1 and C2 of ZCT 10c. These (I) input voltages and (J) input currents are determined by the settings and wiring of voltage generator 71 and current generator 72, so there is no particular need for the user to input data.

[0093] In addition to the (E) T-phase ground fault-occurring zero-phase voltage and (F) T-phase ground fault-occurring zero-phase current shown in FIG. 8, the (C) voltage direction recognized by the protective relay, (D) current direction recognized by the protective relay, (G) T-phase ground fault-occurring zero-phase voltage and (H) T-phase ground fault-occurring zero-phase current are the same as those in the first embodiment (see FIG. 2), and therefore will not be described again.

[0094] FIG. 9 is a flowchart showing the process during testing of the protective relay device (see also FIG. 1A as appropriate). 8, during "START," the ZVT 10v is connected to the voltage generator 71 via the protection relay panel 40, and the ZCT 10c is connected to the current generator 72 via the protection relay panel 50. Furthermore, it is assumed that the wiring between the voltage terminals P1, P2 of the protection relay device 10 and the protection relay panel 40, and the wiring between the current terminals C1, C2 and the protection relay panel 50 are properly performed based on the method of the first embodiment.

[0095] In step S201, the CPU 12 of the protective relay device 10 accepts the selection of (C) ZVT connection information. Specifically, the CPU 12 accepts the selection input of (C) the direction of voltage recognized by the protective relay (see FIG. 8) as the ZVT connection information based on the operation of the user interface 13.

[0096] In step S202, the CPU 12 accepts the selection of (D) ZCT wiring information. Specifically, the CPU 12 accepts the selection input of (D) the direction of current recognized by the protective relay (see FIG. 8) as the ZCT wiring information based on the operation of the user interface 13. Note that the order of the processes in steps S201 and S202 may be changed as appropriate.

[0097] Furthermore, the "data" input in the "input process" (S201, S202) during testing of the protective relay device 10 includes the following information: the direction ((C) of FIG. 8) of the voltage applied between the voltage terminals P1 and P2 of the protective relay device 10 (see FIG. 8) from the voltage generator 71 (see FIG. 8) used for testing, and the direction ((D) of FIG. 8) of the current flowing from the current generator 72 (see FIG. 8) used for testing via the current terminals C1 and C2 of the protective relay device 10.

[0098] More specifically, when a ground fault occurs in one of the three-phase distribution lines 31 (see FIG. 2) to which the protective relay device 10 is connected (for example, the T phase), information indicating the direction of the voltage shown in FIG. 8(C) is input as the direction of the voltage applied between the voltage terminals P1 and P2 of the protective relay device 10. In addition, when a ground fault occurs in one of the three-phase distribution lines 31 (see FIG. 2) to which the protective relay device 10 is connected (for example, the T phase), information indicating the direction of the current ((D) in FIG. 8) is input as the direction of the current flowing through the current terminals C1 and C2 of the protective relay device 10. The specific method of the above-mentioned "input processing" is the same as that in the first embodiment (S104 and S105 in FIG. 5), and therefore the description thereof will be omitted.

[0099] Next, in step S203, the CPU 12 identifies (I) the input voltage and (J) the input current. The phase of the input voltage is identified based on the voltage applied to the ZVT 10v (see FIG. 8) from the voltage generator 71 (see FIG. 8). The phase of the input current is identified based on the current supplied to the ZCT 10c (see FIG. 8) from the current generator 72 (see FIG. 8).

[0100] Next, in step S204, the CPU 12 calculates the phase of the T-phase ground-fault zero-phase-sequence voltage based on a predetermined algorithm. That is, the CPU 12 calculates (E) the T-phase ground-fault zero-phase-sequence voltage (see FIG. 8) that is assumed when a ground fault occurs in the main circuit 30, and also calculates (G) the T-phase ground-fault zero-phase-sequence voltage (see FIG. 8) that is recognized by the protective relay.

[0101] In step S205, the CPU 12 calculates the phase of the T-phase ground-fault zero-phase current based on a predetermined algorithm. That is, the CPU 12 calculates (F) the T-phase ground-fault zero-phase current (see FIG. 8) that is assumed when a ground fault occurs in the main circuit 30, and also calculates (H) the T-phase ground-fault zero-phase current (see FIG. 8) that is recognized by the protective relay.

[0102] In step S206, the CPU 12 displays the calculation result on the user interface 13. In this way, the CPU 12 performs a display process (S206) of displaying the phases of the ground-fault-time zero-phase-sequence voltage ((G) in FIG. 8) and the ground-fault-time zero-phase-sequence current ((H) in FIG. 8) recognized by the protective relay device 10 on the user interface 13 (display device) based on the "data" including (C) and (D) in FIG. 8. In this way, in the second embodiment, the "input process" (S201, 202) and the "display process" (S206) are performed when the protective relay device 10 is tested. After performing the process of step S206, the CPU 12 ends the series of processes (END).

[0103] Figure 10 is an example of a display showing voltage and current vectors when the connections during a protective relay device test are correct. Note that dashed-line frames (C) and (D) in Fig. 10 correspond one-to-one to the dashed-line frames in Fig. 8. Also, solid-line frames (E), (F), (G), (H), (I), and (J) in Fig. 10 correspond one-to-one to the solid-line frames in Fig. 8. When dashed-line frames (C) the direction of voltage recognized by the protective relay and (D) the direction of current recognized by the protective relay are set by a user input operation, the information shown in Fig. 10 is displayed on the user interface 13 (see Fig. 1B) as the calculation result of the CPU 12 (see Fig. 1B).

[0104] In the example of Fig. 10, information on "main circuit voltage and current vectors" and information on "voltage and current vectors recognized by the protective relay" are displayed side by side. Of the information on "main circuit voltage and current vectors," (I) input voltage and (E) T-phase ground fault zero-phase voltage are displayed side by side as information related to the voltage vector of the main circuit 30. In addition, (C) the direction of voltage recognized by the protective relay is displayed below the (I) input voltage on the screen.

[0105] Of the information on "main circuit voltage and current vectors," (J) input current and (F) T-phase ground fault zero-phase current are displayed side by side as information related to the current vector of the main circuit 30. In addition, below the (J) input current on the screen, (D) the direction of the current recognized by the protective relay is displayed.

[0106] Regarding the "voltage and current vectors recognized by the protective relay," (G) the T-phase ground fault zero-phase voltage is displayed next to the (I) input voltage and the (E) T-phase ground fault zero-phase voltage. Also, (H) the T-phase ground fault zero-phase current is displayed next to the (J) input current and the (F) T-phase ground fault zero-phase current. In this way, in the "display process" (S206 in FIG. 9), the CPU 12 (see FIG. 1A) displays the phases of the ground fault zero-phase voltage ((G) in FIG. 10) and the ground fault zero-phase current ((H) in FIG. 10) recognized by the protective relay device 10 as predetermined vectors on the user interface 13 (see FIG. 1A).

[0107] To properly test the protective relay device 10, it is necessary to make (I) the input voltage and (E) the T-phase ground fault zero-phase voltage in phase, and furthermore, to make (J) the input current and (F) the T-phase ground fault zero-phase current in phase. However, there is a possibility that the connection between the protective relay panel 40 (see FIG. 8) and the voltage generator 71 (see FIG. 8) is incorrect, or that the connection between another protective relay panel 50 (see FIG. 8) and the current generator 72 (see FIG. 8) is incorrect.

[0108] In the example of Figure 10, during the test, (I) the input voltage vector VT (E) The zero-phase voltage vector V T Furthermore, the input current vector (J) is T However, (F) the zero-phase current vector I T This allows the user to confirm that the connection of the protection relay device 10 during testing is correct. Note that the fact that the connection of the protection relay device 10 is correct may be displayed on the user interface 13 (see FIG. 1A).

[0109] FIG. 11 is an example of a display showing voltage and current vectors when the input current direction of a protective relay device is incorrect. In addition, Figure 11 shows the input current vector I T The difference is that the direction of is opposite to that in Figure 10 (when the input current direction is correct), but other than that it is the same as Figure 10. Therefore, explanations of parts that overlap with Figure 10 will be omitted. In the example of Figure 11, during the test, (J) the input current vector I T and (F) the zero-phase current vector V T For example, if the connection between the protection relay panel 50 (see FIG. 8) and the current generator 72 (see FIG. 8) is incorrect, the input current vector I T and (F) the vector V of the zero-phase current when the T phase is grounded T and are not in phase, but are in opposite directions.

[0110] For example, if the direction of the input current is incorrect, an error message saying "incorrect input current direction" (see the bottom of FIG. 11) is displayed on the user interface 13 of the protective relay device 10. This makes it possible to notify the user that there is an error in the input current direction of the protective relay device 10. In this way, in the "display process" (S206 in FIG. 9), the CPU 12 (see FIG. 1A) displays a predetermined error message on the user interface 13 (display device: see FIG. 1A) when the phase ((J) in FIG. 11) of the input current flowing from the current generator 72 (see FIG. 8) via the current terminals C1 and C2 differs from the phase ((F) in FIG. 11) of the zero-phase sequence current expected when a ground fault occurs.

[0111] If the phase ((I) in FIG. 11) of the input voltage applied between the voltage terminals P1 and P2 from the voltage generator 71 (see FIG. 8) differs from the phase ((E) in FIG. 11) of the zero-phase sequence voltage expected when a ground fault occurs, the CPU 12 (see FIG. 1A) may display a predetermined error message on the user interface 13 (display device: see FIG. 1A) (S206 in FIG. 9). By performing such display processing, the user can be made aware that there is an error in the input voltage direction of the protective relay device 10.

[0112] <Effects> According to the second embodiment, if a connection is made during testing of the protective relay device 10 and the direction of the input current or input voltage is incorrect, a predetermined error message is displayed (see FIG. 11). This makes it possible to prevent connection errors during testing of the protective relay device 10.

[0113] <<Variations>> Although the data display method for the protective relay device 10 according to the present disclosure has been described in each embodiment, it is not limited to these descriptions and various modifications can be made. For example, in the first embodiment, a case has been described in which (a) the main circuit power factor θ and (A) the main circuit voltage are input as information on the voltage and current of the three-phase distribution line 31 (see FIG. 2 ) when designing the protective relay device 10. However, this is not limiting. That is, (a) the main circuit power factor θ and (B) the main circuit current may be input as information on the voltage and current of the three-phase distribution line 31. Furthermore, (A) the main circuit voltage and (B) the main circuit current may be input as information on the voltage and current of the three-phase distribution line 31.

[0114] The grounding system of the generator including the main circuit 30 (see FIG. 2) described in each embodiment may be a direct grounding system, a resistance grounding system, or a reactor grounding system. The starting system of the generator may be a thyristor starting system, or another starting system such as a half-speed two-axis synchronous system.

[0115] In addition, in each embodiment, the phase of a voltage or current is shown as the direction of a vector on a display screen, but this is not limiting. For example, the phase of a voltage or current may be shown as a predetermined code (or a predetermined code and value). In addition, in each embodiment, the protective relay device 10 is described as including the ZVT 10v (see FIG. 2), the ZCT 10c (see FIG. 2), and the DGR (not shown), but this is not limiting. That is, some or all of the ZVT 10v, the ZCT 10c, and the DGR may be integrated.

[0116] Furthermore, the processing (data display method) of the protection relay device 10 and the computer 20 may be executed as a predetermined program. The program can be provided via a communication line, or can be written to a recording medium such as a CD-ROM and distributed.

[0117] Furthermore, the present disclosure is not limited to each embodiment and includes various modifications. For example, each embodiment has been described in detail to clearly explain the present disclosure, and is not necessarily limited to those including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another example to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace part of the configuration of each embodiment with other configurations.

[0118] Furthermore, the above-mentioned configurations, functions, processing units, processing means, etc. may be partly or entirely implemented in hardware, for example, by designing them as integrated circuits. Furthermore, the above-mentioned configurations, functions, etc. may be implemented in software, with a processor interpreting and executing a program that implements each function. Information such as the programs, tables, and files that implement each function can be stored in a memory, a recording device such as a hard disk or SSD (Solid State Drive), or a recording medium such as an IC card, SD card, or DVD. In addition, the control lines and information lines shown are those that are considered necessary for the explanation, and do not necessarily show all the control lines and information lines in the product. In reality, it can be assumed that almost all components are interconnected. [Explanation of symbols]

[0119] 10. Protective relay devices 10c ZCT 10v ZVT 11. Anomaly detection unit 12 CPU 13 User Interface (Display Device) 14 Input section 15 Output section 20 Computer 21 Main Unit 22 Input Devices 23 Display device 21a Storage section 21b Processing section 21c interface 30 Main circuit 31 Three-phase distribution line 40,50 Protection relay panel 61 ZVT terminal information list 62 ZCT terminal information list 71 Voltage Generator 72 Current Generator Test terminal for 41v, 42v voltage 51c, 52c Current test terminals 103c Secondary Winding C1,C2 current terminal P1, P2 voltage terminals S102, S103, S104, S105 steps (input processing) S108 step (display processing) S201, S202 steps (input processing) S206 Step (display processing)

Claims

1. an input process in which data including a direction of a voltage applied between voltage terminals of the protective relay device when one of three-phase distribution lines to which the protective relay device is connected suffers a ground fault, and a direction of a current flowing through a current terminal of the protective relay device when the distribution line suffers a ground fault; and displaying, on a display device, the phases of the ground-fault zero-phase-sequence voltage and the ground-fault zero-phase-sequence current recognized by the protective relay device based on the data.

2. The input processing and the display processing are performed when the protection relay device is designed, The data input in the input process further includes information on the voltage and current of the three-phase distribution line.

2. The data display method according to claim 1, wherein:

3. In the display process, the phases of the ground fault zero-phase voltage and the ground fault zero-phase current recognized by the protective relay device are displayed as predetermined vectors on an exploded connection diagram of the protective relay device.

3. The data display method according to claim 2, wherein:

4. In the display process, when a phase of a zero-phase sequence voltage at the time of a ground fault recognized by the protective relay device differs from a phase of a zero-phase sequence current at the time of a ground fault recognized by the protective relay device, a predetermined error message is displayed on the display device.

3. The data display method according to claim 2, wherein:

5. The input processing and the display processing are performed during testing of the protection relay device, In the input process, As the direction of the voltage, a direction of a voltage applied between the voltage terminals of the protective relay device from a voltage generator used for testing the protective relay device is used, The direction of the current is the direction of the current flowing from a current generator used in testing the protective relay device through the current terminal of the protective relay device.

2. The data display method according to claim 1, wherein:

6. the display device is a user interface of the protection relay device, In the display process, the phases of the ground fault zero-phase voltage and the ground fault zero-phase current recognized by the protective relay device are displayed on the user interface as predetermined vectors.

6. The data display method according to claim 5,

7. In the display process, when the phase of the input voltage applied between the voltage terminals from the voltage generator differs from the phase of the zero-phase sequence voltage assumed when a ground fault occurs, a predetermined error message is displayed on the display device.

6. The data display method according to claim 5,

8. In the display process, when a phase of an input current flowing from the current generator through the current terminal differs from a phase of a zero-phase sequence current assumed when a ground fault occurs, a predetermined error message is displayed on the display device.

6. The data display method according to claim 5,

9. In the input process, a wiring pattern when a wire is connected to the voltage terminal is selected by a user's input operation as the direction of the voltage included in the data, and a wiring pattern when a wire is connected to the current terminal is selected by a user's input operation as the direction of the current, In the display process, the vectors of the zero-phase-sequence voltage and the zero-phase-sequence current at the time of the earth fault recognized by the protective relay device are displayed on the display device based on predetermined calculation formulas corresponding to the respective connection patterns.

2. The data display method according to claim 1, wherein:

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