Physical simulation platform and detection method for power distribution fault indicator detection

Abstract

The embodiment of the present application provides a physical simulation platform and detection method for power distribution fault indicator detection, the platform includes: 380V system and 10kV system; the 380V system includes: fault generator, 380V bus and simulation line, the simulation line includes 10kV system access points connected in sequence, parameter units for simulating the corresponding simulation line capacitance to ground and load units for simulating user loads, and the simulation line is also provided with a fault access point for connecting the fault generator; the 10kV system includes a high-voltage feeder unit for connecting the power distribution fault indicator, and the high-voltage feeder unit is connected to the 10kV system access point. The structure of the present application is reliable and highly reusable, and can perform performance detection on power distribution fault indicators of different manufacturers or models, ensure the application reliability of the power distribution fault indicator, effectively improve the convenience, efficiency and reliability of power distribution fault indicator detection, and reduce detection costs.

Description

Technical Field

[0001] The present application relates to the technical field of electric power equipment, and in particular to a physical simulation platform and a detection method for power distribution fault indicators. Background Art

[0002] As people's production and life rely more and more on electricity, the safety and stability of the distribution network are becoming more and more important. In a small current grounding system, when a grounding fault occurs, it is difficult to determine the fault line and fault section due to the small fault current. The manual pull test method results in a long fault handling time and power outages on non-fault lines. By installing a distribution fault indicator, the fault section can be directly located, the fault handling time can be reduced, and the scope of power outage can be reduced. Therefore, the reliability of the distribution fault indicator is crucial. Since the fault characteristic quantity of the small current grounding system is not obvious, the algorithms of various types of distribution fault indicators are different, and the positioning accuracy is also very different. In order to ensure the reliable operation of the distribution network, it is necessary to carry out network access detection of the distribution fault indicator.

[0003] However, existing equipment for performance testing of distribution fault indicators has problems such as poor structural reliability or inability to achieve reuse. In addition, due to different technical levels of manufacturers, the quality of products produced varies. Therefore, existing distribution fault indicator testing equipment cannot guarantee the application reliability of distribution fault indicators. Summary of the invention

[0004] In response to the problems in the prior art, the present application provides a physical simulation platform and a detection method for power distribution fault indicator detection. The physical simulation platform for power distribution fault indicator detection has a reliable structure and high reusability, and can perform performance testing on power distribution fault indicators of different manufacturers or models. Furthermore, on the basis of ensuring the application reliability of the power distribution fault indicator, it can effectively improve the convenience, efficiency and reliability of power distribution fault indicator detection and reduce the detection cost.

[0005] In order to solve the above technical problems, this application provides the following technical solutions:

[0006] In a first aspect, the present application provides a physical simulation platform for power distribution fault indicator detection, including: a 380V system and a 10kV system;

[0007] The 380V system includes: a fault generator, a 380V bus and a simulation line connected to the 380V bus, the simulation line includes a 10kV system access point connected in sequence, a parameter unit for simulating the corresponding simulation line-to-ground capacitance and a load unit for simulating the user load, and a fault access point is also provided on the simulation line; the fault access point is used to connect the fault generator;

[0008] The 10kV system includes a high-voltage feeder unit for connecting to a power distribution fault indicator, and the high-voltage feeder unit is connected to the 10kV system access point to perform performance detection on the power distribution fault indicator based on the 380V system.

[0009] Further, the high-voltage feeder unit includes: an access point, a switch, a step-up transformer, a first fuse and a 10kV feeder connected in sequence, and the high-voltage feeder unit also includes: a current transformer, a second fuse and a voltage transformer connected in sequence to the 10kV feeder, the primary side of the voltage transformer is grounded, and the secondary side of the voltage transformer is connected to the second fuse;

[0010] The 10kV feeder is used to connect the power distribution fault indicator;

[0011] The access point is connected to the 10kV system access point.

[0012] Further, the fault generator comprises: a ground fault unit;

[0013] The ground fault unit includes: a ground fault access point, a main switch, an arc ground fault switch, a metal and resistance ground fault switch, a first ground resistance unit and a second ground resistance unit;

[0014] The ground fault access point, the main switch, the arc ground fault switch and the second ground resistance unit are connected in sequence, the metal and resistance ground fault switch is connected in parallel with the arc ground fault switch, and the arc ground fault switch and the metal and resistance ground fault switch are both connected to the first ground resistance unit;

[0015] The ground fault access point is used to connect to the fault access point.

[0016] Further, the first grounding resistance unit includes: a first grounding resistance branch, a second grounding resistance branch, a third grounding resistance branch and a fourth grounding resistance branch connected in parallel, and the first grounding resistance branch, the second grounding resistance branch, the third grounding resistance branch and the fourth grounding resistance branch are all grounded;

[0017] Wherein, the first grounding resistance branch includes a switch, and the second grounding resistance branch to the fourth grounding resistance branch each include a switch and a resistor connected in series;

[0018] Each of the switches in the first grounding resistance unit is connected to an arc grounding fault switch and a metal and resistance grounding fault switch.

[0019] Further, the second grounding resistance unit comprises: a grounding resistance branch, three grounded resistors sequentially connected to one side of the grounding resistance branch, and the grounding resistance branch comprises a resistor and a switch connected in series;

[0020] The other side of the grounding resistance branch is connected to an arc grounding fault switch and a metal and resistance grounding fault switch;

[0021] The grounding resistance branch is connected in parallel with a switch, a branch consisting of the grounding resistance branch and an adjacent resistor is connected in parallel with a switch, and another branch consisting of the grounding resistance branch and two adjacent resistors in sequence is connected in parallel with a switch.

[0022] Further, the fault generator includes: a short circuit fault unit;

[0023] The short-circuit fault unit comprises: a phase power selection switch and three short-circuit branches, and one side of each short-circuit branch is provided with a short-circuit fault access point, and the other side is sequentially connected to a switch and a resistor; each of the short-circuit branches is respectively connected in parallel to a corresponding branch consisting of a switch and a resistor connected to each other;

[0024] The phase power selection switch is arranged between one side of each short-circuit branch and the corresponding short-circuit fault access point;

[0025] Each of the resistors in the short-circuit fault unit is grounded via a switch;

[0026] The short-circuit fault access point is used to connect to the fault access point.

[0027] Furthermore, each of the simulated circuits includes three simulated branches, and each of the simulated branches is connected one-to-one to the three-phase lines of the 380V bus.

[0028] Further, the parameter unit includes: at least one grounding capacitor subunit, each grounding capacitor subunit includes three grounding capacitor branches, and each of the grounding capacitor branches is connected to each of the analog branches one-to-one;

[0029] Each of the grounding capacitor branches is provided with capacitors and switches connected to each other, and each capacitor in the grounding capacitor subunit is grounded.

[0030] Further, the load unit comprises: a first load subunit and a second load subunit;

[0031] The first load subunit comprises: three first load branches, and each of the first load branches is connected to each of the simulation branches one by one; each of the first load branches is provided with a switch and a resistor connected to each other;

[0032] The first load subunit comprises: three second load branches, and each of the second load branches is connected to each of the simulation branches one by one;

[0033] Each of the second load branches is provided with a switch, and the switches in each of the second load branches are respectively connected to the corresponding resistor or are all connected to a start button.

[0034] Furthermore, it also includes: a 380V power supply, which is connected to the 380V bus via an isolation transformer.

[0035] Furthermore, it also includes: two 380V bus voltage transformers both connected to the 380V bus.

[0036] Furthermore, it also includes: a neutral point unit, which is connected to the 380V bus via a grounding transformer;

[0037] The neutral point unit includes a first resistor, a second resistor and an arc extinguishing coil connected in parallel, and the first resistor and the second resistor have different resistance values.

[0038] Furthermore, it also includes: a capacitance parameter unit;

[0039] The capacitance parameter unit includes a first capacitance-to-ground simulation subunit and a second capacitance-to-ground simulation subunit;

[0040] The first ground capacitance simulation subunit includes three first capacitance branches, each of which is connected one-to-one to the three-phase line of the 380V busbar; each of the first capacitance branches includes a capacitor, a switch and an isolating switch connected in sequence;

[0041] The two-to-ground capacitance simulation subunits include three second capacitance branches, each of which is connected one-to-one to the three-phase line of the 380V busbar; each of the second capacitance branches includes a capacitor and an isolating switch connected in sequence;

[0042] The capacitors in the capacitance parameter unit are all grounded.

[0043] Furthermore, the 380V busbar is connected with a fault access point and a transfer arc extinguishing device;

[0044] The transfer type arc extinguishing device comprises three grounded switches connected in parallel, and each of the switches in the transfer type arc extinguishing device is connected one-to-one to the three-phase lines of the 380V busbar.

[0045] In a second aspect, the present application provides a power distribution fault indicator detection method, which is implemented using the power distribution fault indicator detection physical simulation platform, and the power distribution fault indicator detection method includes:

[0046] Connecting a high-voltage feeder unit provided with a power distribution fault indicator to the 10kV system access point, and connecting the fault generator to the fault access point;

[0047] The 380V system is controlled to simulate fault conditions and non-fault conditions, and a performance test result of the power distribution fault indicator is determined according to the operating state of the power distribution fault indicator, wherein the performance test result includes at least one of fault location, low current power supply and false alarm detection results.

[0048] It can be seen from the above technical scheme that the physical simulation platform and detection method for power distribution fault indicator detection provided by the present application, the physical simulation platform for power distribution fault indicator detection includes: a 380V system and a 10kV system; the 380V system includes: a fault generator, a 380V bus and a simulated line connected to the 380V bus, the simulated line includes a 10kV system access point connected in sequence, a parameter unit for simulating the corresponding simulated line-to-ground capacitance and a load unit for simulating the user load, and a fault access point is also provided on the simulated line; the fault access point is used to connect The fault generator; the 10kV system includes a high-voltage feeder unit for connecting a distribution fault indicator, the high-voltage feeder unit is connected to the 10kV system access point to perform performance detection on the distribution fault indicator based on the 380V system, the physical simulation platform for distribution fault indicator detection has a reliable structure and high reusability, and can perform performance detection on distribution fault indicators of different manufacturers or models, thereby effectively improving the convenience, efficiency and reliability of distribution fault indicator detection and reducing detection costs on the basis of ensuring the application reliability of the distribution fault indicator. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0050] Figure 1 It is a schematic diagram of the connection structure of the physical simulation platform for power distribution fault indicator detection in the embodiment of the present application.

[0051] Figure 2 This is a schematic diagram of the connection structure of a 380V system in a physical simulation platform for power distribution fault indicator detection in an embodiment of the present application.

[0052] Figure 3This is a schematic diagram of the connection structure of specific components of a 380V system in a physical simulation platform for power distribution fault indicator detection in an embodiment of the present application.

[0053] Figure 4 It is a structural schematic diagram of a high-voltage feeder unit in a physical simulation platform for power distribution fault indicator detection in an embodiment of the present application.

[0054] Figure 5 It is a structural schematic diagram of a ground fault unit in a physical simulation platform for power distribution fault indicator detection in an embodiment of the present application.

[0055] Figure 6 It is a structural schematic diagram of a short-circuit fault unit in a physical simulation platform for power distribution fault indicator detection in an embodiment of the present application.

[0056] Figure 7 It is a flow chart of the power distribution fault indicator detection method in the embodiment of the present application.

[0057] Figure Number:

[0058] 1. 380V system;

[0059] 11. Fault generator;

[0060] 12. 380V busbar;

[0061] 13. Analog circuit;

[0062] 131, 10kV system access point;

[0063] 132. Faulty access point;

[0064] 1321, first fault access point;

[0065] 1322, second fault access point;

[0066] 1323, third fault access point;

[0067] 1324, fourth fault access point;

[0068] 1325, fifth fault access point;

[0069] 133. Parameter unit;

[0070] 1331, first parameter unit;

[0071] 1332, second parameter unit;

[0072] 1333, third parameter unit;

[0073] 1334, fourth parameter unit;

[0074] 134. Load cell;

[0075] 1341, first load unit;

[0076] 1342, a second load unit;

[0077] 1343, third load unit;

[0078] 1344, fourth load unit;

[0079] 14. First line;

[0080] 15. Second line;

[0081] 16. The third line;

[0082] 17. Fourth line;

[0083] 2. 10kV system;

[0084] 22. High voltage feeder unit;

[0085] 221. Secondary detuning test interface;

[0086] 222. Primary detuning test interface;

[0087] 223, 10kV feeder;

[0088] 4. Power distribution fault indicator;

[0089] 5. 380V power supply;

[0090] 6. Transfer type arc extinguishing device;

[0091] 7. Bus voltage transformer unit;

[0092] 8. Neutral point unit;

[0093] 91. A first ground capacitance simulation subunit;

[0094] 92. A second ground capacitance simulation subunit. DETAILED DESCRIPTION

[0095] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0096] In one or more embodiments of the present application, the power distribution fault indicator may also be referred to as a fault indicator, which refers to a device installed on a power line (overhead line, cable and busbar) to indicate the fault current. Since the single-phase grounding fault current in a small current grounding system is small, it is difficult to achieve fault ranging, and the fault location often requires manual search by line patrol personnel. Therefore, in order to determine the fault point as early as possible, a fault indicator is installed on the line to achieve rapid positioning of the fault point. The fault indicator mainly includes fault identification, energy acquisition and communication units. The fault identification unit identifies the fault through characteristic quantities such as fault current changes and transient zero-sequence current changes, and determines the fault location; the energy acquisition unit obtains electrical energy from the line to ensure the power supply of the fault identification and communication unit; the communication unit can communicate with the main station and alarm after a fault occurs.

[0097] In order to provide structural reliability and reusability of a device for detecting a power distribution fault indicator, the present application provides a physical simulation platform for detecting a power distribution fault indicator. Figure 1 The physical simulation platform for power distribution fault indicator detection specifically includes the following contents:

[0098] 380V system 1 and 10kV system 2; the 380V system 1 specifically includes: a fault generator 11, a 380V bus 12 and a simulation line 13 connected to the 380V bus 12, the simulation line 13 specifically includes a 10kV system access point 131 connected in sequence, a parameter unit 133 for simulating the corresponding simulation line-to-ground capacitance and a load unit 134 for simulating the user load; a fault access point 132 is also provided on the simulation line 13; the fault access point 132 is used to connect the fault generator 11; the 10kV system 2 specifically includes a high-voltage feeder unit 22 for connecting a distribution fault indicator 4, the high-voltage feeder unit 22 is connected to the 10kV system access point 131 to perform performance detection on the distribution fault indicator 4 based on the 380V system 1.

[0099] See also Figures 2 to 6 The 380V bus 12 in the 380V system 1 specifically refers to a simulated 380V bus, which includes three-phase lines: a first line A, a second line B and a third line C. Correspondingly, each simulated line 13 includes three simulated branches, and each simulated branch is connected one-to-one to the first line A, the second line B and the third line C of the 380V bus.

[0100] Understandably, Figure 2The same components arranged on the three lines shown in the figure are represented by one symbol, and it can be understood that the components on the three lines can all be represented by this symbol. For example, the isolating switch QS-X1 on the first line 14 means that isolating switches are respectively provided on each analog branch of the first line 14, and for the convenience of identification and expression, the isolating switches on each analog branch of the first line 14 are uniformly marked as QS-X1.

[0101] In a specific example of the present application, see Figures 2 to 6 The analog branch 13 may consist of four, namely a first line 14, a second line 15, a third line 16 and a fourth line 17.

[0102] First, the first line 14 specifically includes an isolating switch QS-X1 and a circuit breaker QF-X1 connected to each other, and each analog branch of the first line 14 is respectively provided with a current transformer X1TAa, a current transformer X1TAb and a current transformer X1TAc connected to the circuit breaker QF-X1, and the current transformer X1TAa, the current transformer X1TAb and the current transformer X1TAc are all connected to the current transformer X1TAo, and the current transformer X1Tao is respectively connected to the 10kV system of each analog branch of the first line 14. The 10kV system access point 131 of each simulated branch is connected to the corresponding second fault access point 1322, a parameter unit 133 for simulating the corresponding simulated line-to-ground capacitance, and a load unit 134 for simulating the user load; the second fault access point 1322 is used to connect the fault generator 11, wherein the parameter unit 133 corresponding to the first line 14 can specifically select the first parameter unit 1331, and the load unit 134 corresponding to the first line 14 can specifically select the first load unit 1341.

[0103] The first parameter unit 1331 specifically includes: at least one grounding capacitor subunit, each grounding capacitor subunit includes three grounding capacitor branches, and each of the grounding capacitor branches is connected to each of the analog branches one by one; one of the grounding capacitor branches is provided with a capacitor C11 and a switch KM-C11 connected to each other, and the capacitance value C 11 =5.1μF; the other grounding capacitor branch is provided with a capacitor C12 and a switch KM-C12 connected to each other, and the capacitance value C 12 =5.1 μF, and each capacitor in the grounded capacitor subunit is grounded. In addition, the current value Ic1 of the first parameter unit 1331 is Ic1=2A.

[0104] The first load unit 1341 specifically includes: a first load subunit and a second load subunit; the first load subunit specifically includes: three first load branches, and each of the first load branches is connected to each of the simulation branches one by one; each of the first load branches is provided with a switch KM-X1R1 and a resistor R11 connected to each other, and the specification of the resistor R11 is 55Ω, 4A; the first load subunit also specifically includes: three second load branches, and each of the second load branches is connected to each of the simulation branches one by one; each of the second load branches is provided with a switch KM-X1M, and the switch KM-X1M in each of the second load branches is connected to a start button SF1, and the current value I of the second load branch L1 =1A, and the load current of the first load unit 1341 is 5A.

[0105] Secondly, the second line 15 specifically includes an isolating switch QS-X2 and a circuit breaker QF-X2 connected to each other, and each analog branch of the second line 15 is respectively provided with a current transformer X2TAa, a current transformer X2TAb and a current transformer X2TAc connected to the circuit breaker QF-X2, and the current transformer X2TAa, the current transformer X2TAb and the current transformer X2TAc are all connected to the current transformer X2TAo, and the current transformer X2Tao is respectively connected to the 10kV system of each analog branch of the second line 15. The 10kV system access point 131 of each simulated branch is connected to the corresponding third fault access point 1323, the parameter unit 133 for simulating the corresponding simulated line-to-ground capacitance and the load unit 134 for simulating the user load; the third fault access point 1323 is used to connect the fault generator 11, wherein the parameter unit 133 corresponding to the second line 15 can specifically select the second parameter unit 1332, and the load unit 134 corresponding to the second line 15 can specifically select the second load unit 1342.

[0106] The second parameter unit 1332 specifically includes: at least one grounding capacitor subunit, each grounding capacitor subunit includes three grounding capacitor branches, and each of the grounding capacitor branches is connected to each of the analog branches one by one; one of the grounding capacitor branches is provided with a capacitor C21 and a switch KM-C21 connected to each other, and the capacitance value C 21 =15μF; the other grounding capacitor branch is provided with a capacitor C22 and a switch KM-C22 connected to each other, and the capacitance value C 22 =15 μF, and each capacitor in the grounding capacitor subunit is grounded. In addition, the current value Ic2 of the second parameter unit 1332 is Ic2=6A.

[0107] The second load unit 1342 specifically includes: a first load subunit and a second load subunit; the first load subunit specifically includes: three first load branches, and each of the first load branches is connected one-to-one to each of the analog branches; each of the first load branches is provided with a switch KM-X2R1 and a resistor R21 connected to each other, and the specification of the resistor R21 is 44Ω, 5A; the first load subunit also specifically includes: three second load branches, and each of the second load branches is connected one-to-one to each of the analog branches; each of the second load branches is provided with a switch KM-X2R2, and the switch KM-X2R2 in each of the second load branches is connected to its corresponding resistor R22, and the specification of the resistor R22 is 44Ω, 5A, and the load current of the second load unit 1342 is 10A.

[0108] Third, the third line 16 specifically includes an isolating switch QS-X3 and a circuit breaker QF-X3 connected to each other, and each analog branch of the third line 16 is respectively provided with a current transformer X3TAa, a current transformer X3TAb and a current transformer X3TAc connected to the circuit breaker QF-X3, and the current transformer X3TAa, the current transformer X3TAb and the current transformer X3TAc are all connected to the current transformer X3TAo, and the current transformer X3Tao is respectively connected to the 10kV system of each analog branch of the third line 16. The 10kV system access point 131 of each simulated branch is respectively connected to a parameter unit 133 for simulating the corresponding simulated line-to-ground capacitance, a fourth fault access point 1324 corresponding to each of the simulated branches, and a load unit 134 for simulating the user load; the fourth fault access point 1324 is used to connect the fault generator 11, wherein the parameter unit 133 corresponding to the third line 16 can specifically select the third parameter unit 1333, and the load unit 134 corresponding to the third line 16 can specifically select the third load unit 1343.

[0109] The third parameter unit 1333 specifically includes: at least one grounding capacitor subunit, each grounding capacitor subunit includes three grounding capacitor branches, and each of the grounding capacitor branches is connected to each of the analog branches one by one; one of the grounding capacitor branches is provided with a capacitor C31 and a switch KM-C31 connected to each other, and the capacitance value C 31 =5.1μF; the other grounding capacitor branch is provided with a capacitor C32 and a switch KM-C32 connected to each other, and the capacitance value C 32 =15 μF, and each capacitor in the grounding capacitor subunit is grounded. In addition, the current value Ic3 of the third parameter unit 1333 is Ic3=4A.

[0110] The third load unit 1343 specifically includes: a first load subunit and a second load subunit; the first load subunit specifically includes: three first load branches, and each of the first load branches is connected one-to-one to each of the analog branches; each of the first load branches is provided with a switch KM-X3R1 and a resistor R31 connected to each other, and the specification of the resistor R31 is 55Ω, 5A; the first load subunit also specifically includes: three second load branches, and each of the second load branches is connected one-to-one to each of the analog branches; each of the second load branches is provided with a switch KM-X3R2, and the switch KM-X3R2 in each of the second load branches is connected to its corresponding resistor R32, and the specification of the resistor R32 is 55Ω, 4A, and the load current of the third load unit 1343 is 8A.

[0111] Fourthly, the fourth line 17 specifically includes an isolating switch QS-X4 and a circuit breaker QF-X4 connected to each other, and each analog branch of the fourth line 17 is respectively provided with a current transformer X4TAa, a current transformer X4TAb and a current transformer X4TAc connected to the circuit breaker QF-X4, and the current transformer X4TAa, the current transformer X4TAb and the current transformer X4TAc are all connected to the current transformer X4TAo, and the current transformer X4Tao is respectively connected to the 10kV system of each analog branch of the fourth line 17. The 10kV system access point 131 of each simulated branch is respectively connected to a parameter unit 133 for simulating the corresponding simulated line-to-ground capacitance, a respective fifth fault access point 1325 and a load unit 134 for simulating the user load; the fifth fault access point 1325 is used to connect the fault generator 11, wherein the parameter unit 133 corresponding to the fourth line 17 can specifically select the fourth parameter unit 1334, and the load unit 134 corresponding to the fourth line 17 can specifically select the fourth load unit 1344.

[0112] The fourth parameter unit 1334 specifically includes: a grounding capacitor subunit, including three grounding capacitor branches, and each of the grounding capacitor branches is connected to each of the analog branches one-to-one; the grounding capacitor branch is provided with a capacitor C41 and a switch KM-C41 connected to each other, and the capacitance value C4=15μF; and each capacitor in the grounding capacitor subunit is grounded. In addition, the current value Ic4 of the fourth parameter unit 1334 is 3A.

[0113] The fourth load unit 1344 specifically includes: a first load subunit and a second load subunit; the first load subunit specifically includes: three first load branches, and each of the first load branches is connected to each of the simulation branches one by one; each of the first load branches is provided with a switch KM-X4R1 and a resistor R41 connected to each other, and the specification of the resistor R41 is 44Ω, 5A; the first load subunit also specifically includes: three second load branches, and each of the second load branches is connected to each of the simulation branches one by one; each of the second load branches is provided with a switch KM-X4M, and the switch KM-X4M in each of the second load branches is connected to a start button SF2, and the current value I of the second load branch L2 =1A, and the load current of the fourth load unit 1344 is 6A.

[0114] Also, see Figures 2 to 6 The physical simulation platform for power distribution fault indicator detection also specifically includes: a 380V power supply 5, which can be connected to the 380V busbar via an isolation transformer ZT. The circuit where the 380V power supply 5 is located specifically includes: a first power supply line connected to the first line A, a second power supply line connected to the second line B, and a third power supply line connected to the third line C. The first power supply line, the second power supply line, and the third power supply line are all provided with interconnected isolation switches QS-Z1, and each isolation switch QS-Z1 is respectively connected to its corresponding switch KM-Z1, and each switch KM-Z1 is respectively connected to a current transformer Z1TA, a current transformer Z2TA, and a current transformer Z3TA one-to-one. Each of the switches KM-Z1 and the corresponding current transformers are directly connected to the 380V busbar voltage transformer ZTV via a circuit breaker QF-PT, and the current transformers Z1TA, Z2TA, and Z3TA are all connected to the isolation transformer. The isolating transformer ZT is respectively connected to the isolating switches QS-Z2 corresponding to the first power supply line, the second power supply line and the third power supply line, and each isolating switch QS-Z2 is respectively connected to the switch KM-Z2 one-to-one, and each switch KM-Z2 is respectively connected to the current transformer Z2TAa, the current transformer Z2TAb and the current transformer Z2Tac corresponding to the first power supply line, the second power supply line and the third power supply line, and the current transformer Z2TAa, the current transformer Z2TAb and the current transformer Z2Tac are all connected to one current transformer Z2TAa.

[0115] The 380V bus of the physical simulation platform for power distribution fault indicator detection is also connected to a first fault access point 1321 and a transfer type arc extinguishing device 6; the transfer type arc extinguishing device 6 specifically includes three grounded switches in parallel, namely switch KM-XHC, switch KM-XHB and switch KM-XHA, and the switches KM-XHC, switch KM-XHB and switch KM-XHA in the transfer type arc extinguishing device are respectively connected one-to-one to the third line C, the second line B and the first line A of the 380V bus.

[0116] The physical simulation platform for power distribution fault indicator detection also specifically includes: two bus voltage transformer units 7, each bus voltage transformer unit 7 includes a 380V bus voltage transformer connected to the 380V bus, namely 380V bus voltage transformer ZTV1 and 380V bus voltage transformer ZTV2. The 380V bus voltage transformer ZTV1 is connected to the 380V bus via switch KM-PT2 and circuit breaker QF-PT2 respectively; the 380V bus voltage transformer ZTV2 is connected to the 380V bus via circuit breaker QF-PT1.

[0117] The physical simulation platform for power distribution fault indicator detection also specifically includes: a neutral point unit 8, which can be connected to the 380V busbar via a grounding transformer JDB; the neutral point unit specifically includes a first resistor, a second resistor and an arc suppression coil connected in parallel, and the resistance values ​​of the first resistor and the second resistor are different. The first resistor is a small resistor NR1, and the small resistor NR1 is connected to the current transformer NTA via a switch KM-N1, the second resistor is a high resistor NR2, and the high resistor NR2 is connected to the current transformer NTA via a switch KM-N2, the arc suppression coil NXH is connected to the current transformer NTA via a switch KM-N3, the current transformer NTA is connected to the grounding transformer JDB, and the grounding transformer JDB is connected to the 380V busbar via a switch KM-JDB and a circuit breaker QF-JDB.

[0118] The physical simulation platform for power distribution fault indicator detection further specifically includes: a capacitance parameter unit, and the capacitance parameter unit specifically includes a first ground capacitance simulation subunit 91 and a second ground capacitance simulation subunit 92 .

[0119] The first ground capacitance simulation subunit 91 specifically includes three first capacitance branches, each of which is connected one-to-one to the three-phase lines of the 380V bus; each of the first capacitance branches includes a capacitor, a switch and an isolating switch connected in sequence; specifically, the capacitor MCa2 on a first capacitance branch is connected to the isolating switch QF-MC2A via the switch KM-MC2, the capacitor MCb2 on another first capacitance branch is connected to the isolating switch QF-MC2B via the switch KM-MC2, and the capacitor MCc2 on another first capacitance branch is connected to the isolating switch QF-MC2C via the switch KM-MC2. The isolating switch QF-MC2A, the isolating switch QF-MC2B and the isolating switch QF-MC2C are all connected to the 380V bus, and the resistance value Cm1 of the first ground capacitance simulation subunit 91 is 2.55μF.

[0120] The two-to-ground capacitance simulation sub-unit 92 specifically includes three second capacitance branches, each of which is connected one-to-one to the three-phase lines of the 380V bus; each of the second capacitance branches includes capacitors and isolating switches connected in sequence; specifically, the capacitor MCa1 on one second capacitance branch is connected to the 380V bus via the isolating switch QF-MC1A, the capacitor MCb1 on another second capacitance branch is connected to the 380V bus via the isolating switch QF-MC1B, and the capacitor MCc1 on another second capacitance branch is connected to the 380V bus via the isolating switch QF-MC1C. The capacitors in the capacitance parameter unit are all grounded, and the resistance value Cm1 of the two-to-ground capacitance simulation sub-unit 92 is 5.1μF.

[0121] In one embodiment of the physical simulation platform for power distribution fault indicator detection of the present application, the high-voltage feeder unit 22 specifically includes: a high-voltage feeder access point, a switch, a step-up transformer, a first fuse and a 10kV feeder 223 connected in sequence, and the 10kV feeder 223 is used to connect the power distribution fault indicator 4; the high-voltage feeder unit also specifically includes: a current transformer, a second fuse and a voltage transformer connected in sequence to the 10kV feeder, and the primary side of the voltage transformer is grounded; a secondary deharmonic test interface 221 is provided between the secondary side of the voltage transformer and the second fuse; the high-voltage feeder access point is connected to the 10kV system access point.

[0122] See also Figure 4 There are three groups of high voltage feeder access points, one of which is access point A. L and access point A N , used to connect the 10kV system access point 131 of the first analog branch in the analog line 13, the first analog branch is the line connected to the first line A of the 380V bus 12; the second is the access point B L and access point BN , a 10kV system access point 131 for connecting the second analog branch in the analog line 13, the second analog branch being a line connected to the second line B of the 380V bus 12; the third is an access point C L and access point C N , used to connect a 10kV system access point 131 of the third simulated branch in the simulated line 13, where the third simulated branch is a line connected to the third line C of the 380V bus 12.

[0123] The access point A in the high voltage feeder unit 22 L 、Access Point A N 、Access Point B L 、Access Point B N , Access Point C L and access point C N The step-up transformer PT-XGs is connected to the step-up transformer PT-XGs through the switch KM-XG, and the step-up transformer PT-XGs is connected to the first fuse FU-XGs corresponding to each group of high-voltage feeder access points, and the first fuse FU-XGs is connected to the current transformer TA-XGc corresponding to each group of high-voltage feeder access points, and the current transformer TA-XGc is connected to the second fuse FU-XGc corresponding to each group, and the second fuse FU-XGc is connected to the secondary side of the voltage transformer PT-XGc, and a secondary detuning test interface 221 is provided between the secondary side of the voltage transformer PT-XGc and the second fuse FU-XGc; the secondary detuning test interface 221 is used to connect the secondary detuning device. The primary side of the voltage transformer PT-XGc is grounded, and the primary side of the voltage transformer PT-XGc is provided with a primary detuning test interface 222, and the primary detuning test interface 222 is used to connect the primary detuning device.

[0124] In one embodiment of the physical simulation platform for power distribution fault indicator detection of the present application, the fault generator specifically includes: a ground fault unit;

[0125] See also Figure 5The ground fault unit specifically includes: a ground fault access point JGZ, a main switch KM-JZ-1, a current transformer JTA, an arc ground fault switch KM-J1, a metal and resistance ground fault switch KM-J2, a first ground resistance unit and a second ground resistance unit; the ground fault access point JGZ, the main switch KM-JZ-1, the arc ground fault switch KM-J1 and the second ground resistance unit are connected in sequence, the metal and resistance ground fault switch KM-J2 is connected in parallel with the arc ground fault switch KM-J1, and the arc ground fault switch KM-J1 and the metal and resistance ground fault switch KM-J2 are both connected to the first ground resistance unit; the ground fault access point JGZ is used to connect to the fault access point 132.

[0126] The first grounding resistor unit specifically includes: a first grounding resistor branch, a second grounding resistor branch, a third grounding resistor branch and a fourth grounding resistor branch connected in parallel, and the first grounding resistor branch, the second grounding resistor branch, the third grounding resistor branch and the fourth grounding resistor branch are all grounded;

[0127] The first grounding resistor branch specifically includes a switch KM-J3, with a resistance value of R=0Ω; the second grounding resistor branch specifically includes a switch KM-J4 and a resistor J1R connected in series, with a resistance value of R=7.5Ω; the third grounding resistor branch specifically includes a switch KM-J5 and a resistor J2R connected in series, with a resistance value of R=15Ω; the fourth grounding resistor branch specifically includes a switch KM-J6 and a resistor J3R connected in series, with a resistance value of R=30Ω. Each of the switches in the first grounding resistor unit is connected to an arc grounding fault switch and a metal and resistance grounding fault switch.

[0128] Among them, the second grounding resistance unit specifically includes: a grounding resistance branch, three grounding resistors connected to one side of the grounding resistance branch in sequence, namely, a resistor J7R with a resistance value of R=60Ω, a resistor J6R with a resistance value of R=60Ω, a resistor J5R with a resistance value of R=60Ω, a resistor J4R with a resistance value of R=60Ω and a switch KM-J10, a switch KM-J9 is connected in parallel between switch KM-J10 and resistor J4R, a switch KM-J8 is connected in parallel between resistor J5R, resistor J4R and switch KM-J10, and a switch KM-J7 is connected in parallel between resistor J6R, resistor J5R, resistor J4R and switch KM-J10.

[0129] In one embodiment of the physical simulation platform for power distribution fault indicator detection of the present application, the fault generator specifically includes: a short circuit fault unit;

[0130] See also Figure 6The short-circuit fault unit specifically includes: a phase power selection switch KM-DZ and three short-circuit branches, and each short-circuit branch is provided with a short-circuit fault access point DGZ on one side, and the other side is connected to a corresponding switch and a resistor respectively through a one-to-one corresponding current transformer DTAa, a current transformer DTAb and a current transformer DTAc; each of the short-circuit branches is respectively connected in parallel with a corresponding branch consisting of a switch and a resistor connected to each other; the phase power selection switch KM-DZ is arranged between one side of each of the short-circuit branches and the corresponding short-circuit fault access point; each of the resistors in the short-circuit fault unit is grounded via a switch; the short-circuit fault access point is used to connect to the fault access point 132. Specifically, the current transformer DTAa connects the switch KM-D2-A and the resistor with a resistance value of R=3.8Ω in sequence, and the branch where the switch KM-D2-A and the resistor with a resistance value of R=3.8Ω are located is connected in parallel with the branch where the switch KM-D1-A and a resistor with a resistance value of R=1.8Ω are located; the current transformer DTAb connects the switch KM-D2-B and the resistor with a resistance value of R=3.8Ω in sequence, and the branch where the switch KM-D2-B and the resistor with a resistance value of R=3.8Ω are located is connected in parallel with the branch where the switch KM-D1-B and a resistor with a resistance value of R=1.8Ω are located; the current transformer DTAc connects the switch KM-D2-C and the resistor with a resistance value of R=3.8Ω in sequence, and the branch where the switch KM-D2-C and the resistor with a resistance value of R=3.8Ω are located is connected in parallel with the branch where the switch KM-D1-C and a resistor with a resistance value of R=1.8Ω are located.

[0131] In order to provide structural reliability and reusability of a device for detecting a power distribution fault indicator, the present application embodiment provides a method for detecting a power distribution fault indicator implemented by using a physical simulation platform for detecting a power distribution fault indicator provided by the present application, see Figure 7 , the power distribution fault indicator detection method specifically includes the following contents:

[0132] Step 100: Connecting a high-voltage feeder unit provided with a power distribution fault indicator to the 10 kV system access point, and connecting the fault generator to the fault access point;

[0133] Step 200: Control the 380V system to simulate fault conditions and non-fault conditions, and determine the performance test result of the power distribution fault indicator according to the operating status of the power distribution fault indicator, wherein the performance test result includes at least one of: fault location, low current power supply and false alarm detection result.

[0134] From the above description, it can be seen that the distribution fault indicator detection method provided in the embodiment of the present application can perform performance testing on power distribution fault indicators of different manufacturers or models, and thus can effectively improve the convenience, efficiency and reliability of power distribution fault indicator detection and reduce the detection cost while ensuring the application reliability of the power distribution fault indicator.

[0135] To further illustrate this solution, in a specific application example of this application, a power distribution physical simulation platform is used to realize the simulation of ferromagnetic resonance and various fault conditions. The platform includes a 380V system and a 10kV system. The 380V system includes a main transformer, a busbar, an outgoing line unit, a neutral point grounding module, a short-circuit fault simulation unit, a grounding fault simulation unit, a control unit, and a protection unit; the 10kV system includes a step-up transformer, a simulated line, a PT, and a capacitor. The 380V system simulates various operating and fault conditions, and the 10kV system realizes the performance detection of the distribution device.

[0136] The system is powered by a 380V power supply, and the 380V simulated bus is powered by an isolation transformer ZT. The bus leads to the system neutral point through the grounding transformer JDB, and the system neutral point grounding method is selected through the conversion switch (ungrounded, high-resistance grounding, low-resistance grounding, arc suppression coil grounding, one of the four options). For detailed descriptions, see the neutral point device description in the module description. ZTV1 and ZTV2 are 380V bus voltage transformers used to measure bus voltage. KM-MC2 is a capacitance parameter unit used to simulate the real bus capacitance parameters to ground.

[0137] The platform includes 4 simulation lines, including 10kV system access point (colored dots in the CAD image), fault access point, parameter unit, and load unit. The 10kV system access point can be connected to the high-voltage feeder unit to realize the performance detection of 10kV distribution fault indicator, detuning device and other devices; the fault access point can be connected to the ground fault generator or short circuit fault generator to simulate various faults; the parameter unit simulation line realizes the simulation of real line parameters; the load unit is used to simulate the user load.

[0138] Select the fault mode (grounding or short circuit) through the selection switch; select the short circuit fault mode (50A three-phase; 50A two-phase) through the conversion switch; the fault simulation unit is controlled by the switching switch according to the fault simulation type, and the control unit relay is selectively controlled according to the fault type (high resistance grounding, metal grounding, arc grounding, two-phase short circuit, three-phase short circuit), but the above two faults are not allowed to occur at the same time (software lockout);

[0139] When the system grounding mode is "neutral point ungrounded, low resistance grounding, high resistance grounding, grounding through arc suppression coil", the control node closing time of the fault type (high resistance grounding, metal grounding, arc grounding, two-phase short circuit, three-phase short circuit) is 1s (time adjustable);

[0140] When a single-phase grounding fault occurs in the system, the controller calculates a delay of 0.3S (the time is adjustable) from the beginning of the fault, and then the system quickly switches on the busbar arc extinguishing device.

[0141] (I) Control unit and protection device

[0142] The control unit is controlled according to different functions of the system. A centralized control unit is installed in each cabinet, including the power transformer cabinet, neutral point cabinet, first feeder cabinet, second feeder cabinet and fault simulation cabinet. Siemens S7-200PLC is used for independent modular control. The on-site communication system communicates with the background host, and the operator can complete the debugging and fault simulation of the physical simulation platform at the engineer station.

[0143] The main transformer incoming and outgoing lines and feeder lines are equipped with separate protection devices with voltage and current protection functions; they are also equipped with voltage and current precise measurement functions.

[0144] Each feeder outgoing line switch is equipped with a separate measuring device with voltage and current protection functions; it has the function of accurate voltage and current measurement.

[0145] (II) Technical indicators

[0146] System power supply: three-phase, 380V, 100A, 50Hz;

[0147] Line full load working current: 10A;

[0148] Line short-circuit current: 1000A;

[0149] System current capacity: 30A;

[0150] Normal operation voltage transformer PT secondary voltage: 100V;

[0151] Normal operation current transformer CT secondary current: <=5A;

[0152] The overall measurement accuracy of the system is 0.5 level.

[0153] (III) Main equipment and parameters

[0154] 3.1. Cabinet size (GGD)

[0155] Power transformer cabinet: 1000×800×2200mm (width×depth×height);

[0156] Neutral point cabinet: 1200×800×2200mm (width×depth×height)

[0157] Feeder line 1 cabinet: 1000×800×2200mm (width×depth×height);

[0158] Feeder 2 cabinet: 1000×800×2200mm (width×depth×height)

[0159] High-voltage feeder cabinet: 1500×800×2200mm (width×depth×height);

[0160] Fault simulation cabinet: 1200×800×2200mm (width×depth×height);

[0161] Fault recording screen: 800×800×2200mm (width×depth×height);

[0162] Comprehensive test screen: 800×800×2200mm (width×depth×height).

[0163] 3.2. Main Transformer

[0164] Rated voltage: 380V;

[0165] Rated current: 60A;

[0166] Transformation ratio: 380V / 380V;

[0167] Insulation type: epoxy resin casting;

[0168] Rated capacity: 40kVA;

[0169] Group: YN / zn11;

[0170] 1min power frequency withstand voltage: 35kV.

[0171] 3.3. Arc suppression coil

[0172] Rated voltage: 220V;

[0173] Rated current: 33A;

[0174] Adjustment range: 3~30A;

[0175] 1min power frequency withstand voltage: 3kV.

[0176] 3.4. Neutral point resistance (high resistance)

[0177] Resistance: 220Ω;

[0178] Short-time rated current: 20A.

[0179] 3.5. Neutral point resistance (low resistance)

[0180] Resistance: 3.34Ω;

[0181] Short-time rated current: 66A, 10S.

[0182] 3.6. Class I load

[0183] Load type: resistance;

[0184] Rated current: 3A, 2A, 1A;

[0185] Temperature rise: 30K.

[0186] Design Description:

[0187] Single group design parameters: 1A, 220Ω, 220W*3, star wiring.

[0188] Selection: single parameter 5A, 220Ω, 5500W, 3 star wiring (1 group). The power of a single resistor is 25 times the rated power, mainly considering its surface temperature rise;

[0189] Based on the single parameter 5A, 220Ω, 5500W, 3 star connections (1 group) as the reference control, a single group of 1A is achieved.

[0190] There are 4 groups of resistive loads, in the combination of 3A, 2A, and 1A. The first group of loads IR1 = 1A, the second group of loads IR2 = 2A, the third group of loads IR3 = 1A, and the fourth group of loads IR4 = 3A.

[0191] 3.7. Class II load

[0192] Load type: Motor

[0193] Rated current: 0.3A, 0.6A

[0194] Design Description:

[0195] Fan design parameters: three-phase, 380V, 0.3A, 100W per set;

[0196] Design parameters of the blower: three-phase, 380V, 0.2A, 40W four groups (feeder cabinet and fault simulation cabinet);

[0197] There are three groups of impact loads (motors) in total, the first group of loads I1 = 0.3A, the second group of loads IR2 = 0.6A, and the third group of loads IR3 = 0.9A.

[0198] 3.8. Fault simulation resistance

[0199] Type: resistor;

[0200] Rated current: 100A(5s), 50A(5s), 5A.

[0201] 3.9. Inductance

[0202] Rated current: 50A;

[0203] Voltage drop: 2% for each unit, two units connected in series when used in a single line;

[0204] Rated voltage: 0.38kV;

[0205] Rated capacity: 18.5KW.

[0206] 3.10. Power capacitor

[0207] Type: three-phase capacitor;

[0208] Rated current: 5A;

[0209] Rated voltage: 1.9kV;

[0210] Working voltage: 0.38kV;

[0211] Rated capacitance: 16.5uF;

[0212] Rated capacity: 14.5Kvar.

[0213] 3.11. Step-up transformer

[0214] Rated voltage: 10.5kV;

[0215] Voltage transformation ratio: 0.38 / / 10 / ;

[0216] Insulation type: epoxy resin casting (three-phase combination Y / y0);

[0217] Rated capacity: 20VA.

[0218] 3.12. Voltage transformer - high voltage measurement

[0219] Rated voltage: 10kV;

[0220] Voltage transformation ratio: 10 / √3 / 0.1 / √3 / 0.1 / 3 (three-phase combination Y0 / y0 / △, 0.2 level);

[0221] Insulation type: epoxy resin casting, three-phase five-column type;

[0222] Rated capacity: 15VA.

[0223] 3.13. Voltage transformer-busbar low voltage measurement

[0224] Rated voltage: 0.38kV;

[0225] Voltage transformation ratio: 0.38 / √3 / 0.1 / √3 / 0.1 / 3 (three-phase combination Y0 / y0 / △, 0.2 level);

[0226] Insulation type: non-encapsulated structure, three-phase five-column type;

[0227] Rated capacity: 20VA.

[0228] 3.14. High voltage fuse

[0229] Model: XRNP-12 / 0.5A, including fuse and holder;

[0230] Quantity: 6 sets, for step-up transformer and 10kV voltage transformer.

[0231] 3.15. Circuit Breaker

[0232] Molded case circuit breaker 1 (main circuit + outgoing line + short circuit fault simulation)

[0233] Brand: Schneider;

[0234] Model:CVS160B;

[0235] Order number: LV516303;

[0236] Type: Fixed front connection, 3 poles, In=160, electromagnetic TM-D protection;

[0237] Dimensions: (W x H x D, mm) = 105 x 161 x 86;

[0238] Quantity: To be determined.

[0239] 3.16. Current transformer

[0240] Model:LMZ1-0.66;

[0241] Parameters: 10VA, 100 / 5, 0.2S;

[0242] Insulation type: epoxy casting.

[0243] 3.17. Fault recording

[0244] Sampling rate:

[0245] The maximum sampling rate of the host single channel A / D is 100KSBS, and the actual sampling rate is 5kHz (100 points per cycle). The 4 cycles before the fault and the 8 cycles after the fault are recorded.

[0246] Fault recording start conditions:

[0247] Zero-sequence voltage start: As long as the system zero-sequence voltage exceeds the set start value (secondary value, default 10V, adjustable), the host will immediately start recording;

[0248] Phase current start: As long as the phase current at any point in the system exceeds the set start value (secondary value, default 2A, adjustable), the host will immediately start recording;

[0249] Set the startup value: The file for setting the startup value is in the "CTPT" subfile in the XDL folder of the host NANDFLASH disk. Open the "CTPT" subfile and you will see 4 lines of numbers. The third line is the zero-sequence voltage startup value; the fourth line is the phase current startup value. You can change the startup value according to actual needs and save it after changing it.

[0250] (IV) Module Unit

[0251] 4.1. Interface reservation

[0252] Several access points are reserved in the system, all of which are multiplexed interfaces that can access multiple modules such as single-phase grounding fault, short circuit fault, power supply, load, and communication.

[0253] 4.2. Load cell

[0254] Various types of load units can be easily connected through the access port.

[0255] Equipped with 1 set of load units, composed of continuously adjustable resistance, inductance and capacitance load system, it can generate a maximum load current of 10A, and can simulate various power conditions such as three-phase load imbalance, sudden load addition and unloading, and different power factors leading and lagging.

[0256] 4.3. Fault simulation unit

[0257] Through the access port, the fault simulation unit module can be connected, including short circuit fault and single-phase grounding fault.

[0258] Short circuit fault unit: can simulate two-phase short circuit and three-phase short circuit, and the short circuit current is controllable. Configure protection device. Select two-phase interphase fault or three-phase interphase fault through switch, and the switch can select the fault resistance of interphase fault.

[0259] Ground fault unit: Single-phase ground fault unit, can simulate single-phase ground faults including: metallic grounding, grounding with different resistance values, arc grounding, arc grounding faults with transition resistance, etc. Ground resistance selection switch, can select 0-240Ω grounding resistance adjustment. Through different switch combinations, simulate metallic grounding, grounding with different resistance values, metallic arc grounding, arc grounding with transition resistance.

[0260] 4.4. Neutral point equipment

[0261] An independent grounding transformer is configured to lead out the system neutral point. The conversion switch can be used to achieve the neutral point being ungrounded (all switches are turned on), the neutral point being grounded through a low resistance, the neutral point being grounded through an arc suppression coil, etc. The grounding transformer JDB adopts a Z-type connection with a capacity of 8.8kVA; the arc suppression coil capacity is 8.8kVA, 11 gears, manual adjustment, current compensation range of 10-40A, the step difference does not exceed 3A, manual adjustment; low resistance uses 3.34Ω66A 10s; high resistance uses 220Ω1A 10s; and a signal source interface is reserved.

[0262] 4.5. High voltage feeder unit

[0263] The high-voltage feeder unit increases the voltage from 380V to 10kV through a step-up transformer. The 10kV feeder 223 is a closed circular ring. The circular ring can be used to install an actual 10kV distribution fault indicator for performance verification of the distribution fault indicator. The step-up transformer is a 10kV true PT. The primary neutral point has a primary detuning device installation interface reserved for it, and the secondary side has a secondary detuning device interface reserved for performance verification of the detuning device.

[0264] (V) Platform Function Description

[0265] The platform simulates the switching of four lines and knife switch operations by opening and closing the QS-X1-4 and QF-X1-4 switches; the inductive load is input by closing the switches KM-X1M and KM-X4M, and the resistive load is input by switches KM-X1R1 to KM-X4R1, thereby simulating load changes and adjusting the load current.

[0266] Component Status:

[0267] 1) Fault location test:

[0268] Test steps:

[0269] a. Install a power distribution fault indicator on the platform;

[0270] b. Start the platform and set the fault parameters in the power distribution fault indicator installation section;

[0271] c. Put the faulty unit into operation and record whether the power distribution fault indicator operates correctly;

[0272] d. Remove the fault;

[0273] e. Change the fault parameters and repeat steps cd;

[0274] f. Complete all types of faults at all fault locations;

[0275] g. Close the platform and end the test;

[0276] h. Summarize the correctness of the operation of the distribution fault indicator.

[0277] Testing and evaluation criteria:

[0278] The accuracy of identifying short circuit faults, metallic grounding faults, and medium resistance grounding faults should reach 100%, the accuracy of arc grounding faults should reach 80%, and the accuracy of high resistance grounding faults should reach 70%; after the distribution fault indicator identifies the fault, it should be able to correctly issue a flip or flash alarm and send data to the master station at the same time.

[0279] 2) Small current power supply test:

[0280] When the power distribution fault indicator is underpowered, the recording and data transmission will be incomplete, thus reducing reliability. The simulated line current can be changed by adjusting the load of the simulation platform. When the line current is set to 5A, the fault identification, alarm, and data transmission capabilities of the power distribution fault indicator can be verified.

[0281] Test steps:

[0282] a. Install a power distribution fault indicator on the platform;

[0283] b. Start the platform and set the fault parameters in the power distribution fault indicator installation section;

[0284] c. Adjust the load and set the line current to 5A;

[0285] d. Put the faulty unit into operation and check whether the alarm function of the power distribution fault indicator is normal;

[0286] e. Remove the fault;

[0287] f. Close the platform and end the test;

[0288] g. Check whether the recording and data transmission functions of the power distribution fault indicator are normal.

[0289] 3) False alarm test (new test content)

[0290] By simulating line switching and load change conditions on the platform, the distribution fault indicator should not misjudge it as a ground fault, thereby verifying the false alarm capability of the distribution fault indicator.

[0291] Test steps:

[0292] a. Install a power distribution fault indicator on the platform;

[0293] b. Start the platform;

[0294] c. Perform the switching on and off of each simulated line and record whether the power distribution fault indicator gives a false alarm;

[0295] d. Switch on and off the resistive and inductive loads respectively, and record whether the power distribution fault indicator gives false alarms;

[0296] e. Close the platform and end the test;

[0297] Testing and evaluation criteria:

[0298] The distribution fault indicator shall not give false alarms when lines are switched or loads change.

[0299] That is to say, this application has developed a distribution fault indicator performance detection device based on a distribution physical simulation platform, and proposed a corresponding detection method. The distribution physical simulation platform is used to simulate various grounding, short-circuit faults, normal switching, load changes and other working conditions to detect the fault identification accuracy of the distribution fault indicator. It can detect various principle types of distribution fault indicators, and at the same time simulate small current operating conditions, detect the energy supply capacity of the device, and realize comprehensive performance detection of the distribution fault indicator. The distribution physical simulation platform is used to realize the simulation of ferromagnetic resonance and various fault conditions. The platform includes a 380V system and a 10kV system. The 380V system includes a main transformer, a busbar, an outgoing line unit, a neutral point grounding module, a short-circuit fault simulation unit, a grounding fault simulation unit, a control unit, and a protection unit; the 10kV system includes a step-up transformer, a simulated line, a PT, and a capacitor. The 380V system simulates various operating and fault conditions, and the 10kV system realizes the performance detection of the distribution device.

[0300] The 10kV simulated conductor is an insulated conductor, and the distribution fault indicator can be directly installed on the simulated conductor. The 380V system relies on the short-circuit fault unit to simulate two-phase short circuit and three-phase short circuit, and the grounding fault unit simulates metallic grounding, grounding through different resistance values, arc grounding, arc grounding through transition resistance, etc. By setting various faults in the distribution fault indicator installation section (fault parameters are shown in Table 1), it is verified whether the distribution fault indicator can correctly identify and alarm; by setting various faults in other sections, it is verified whether the distribution fault indicator malfunctions; the distribution fault indicator installation line is switched, switched, and load transferred to verify whether the distribution fault indicator malfunctions; the load is adjusted to make the simulated line current 5A, and the fault is set. The distribution fault indicator can work reliably when the power is drawn from a small current. Since the platform simulates the real 10kV fault and operating conditions, it is suitable for performance testing of distribution fault indicators of various principles and types.

[0301] Table 1

[0302] Grounding location Busbar, feeder Ground resistance / Ω 0 (metallic), 60 (medium resistance), 180 (high resistance) Grounding method Continuous grounding, arc grounding Failure mode Single-phase grounding, phase-to-phase short circuit

[0303] The performance test of the power distribution fault indicator is carried out as follows:

[0304] 1) Fault location test:

[0305] Faults are set in the distribution fault indicator installation section and other sections according to various fault parameters shown in Table 1 to verify whether the distribution fault indicator can correctly locate the fault.

[0306] Test steps:

[0307] a. Install a power distribution fault indicator on the platform;

[0308] b. Start the platform and set the fault parameters in the power distribution fault indicator installation section;

[0309] c. Put the faulty unit into operation and record whether the power distribution fault indicator operates correctly;

[0310] d. Remove the fault;

[0311] e. Change the fault parameters and repeat steps cd;

[0312] f. Complete all types of faults at all fault locations;

[0313] g. Close the platform and end the test;

[0314] h. Summarize the correctness of the operation of the distribution fault indicator.

[0315] Testing and evaluation criteria:

[0316] The accuracy of identifying short circuit faults, metallic grounding faults, and medium resistance grounding faults should reach 100%, the accuracy of arc grounding faults should reach 80%, and the accuracy of high resistance grounding faults should reach 70%; after the distribution fault indicator identifies the fault, it should be able to correctly issue a flip or flash alarm and send data to the master station at the same time.

[0317] 2) Small current power supply test:

[0318] When the power distribution fault indicator is underpowered, the recording and data transmission will be incomplete, thus reducing reliability. The simulated line current can be changed by adjusting the load of the simulation platform. When the line current is set to 5A, the fault identification, alarm, and data transmission capabilities of the power distribution fault indicator can be verified.

[0319] Test steps:

[0320] a. Install a power distribution fault indicator on the platform;

[0321] b. Start the platform and set the fault parameters in the power distribution fault indicator installation section;

[0322] c. Adjust the load and set the line current to 5A;

[0323] d. Put the faulty unit into operation and check whether the alarm function of the power distribution fault indicator is normal;

[0324] e. Remove the fault;

[0325] f. Close the platform and end the test;

[0326] g. Check whether the recording and data transmission functions of the power distribution fault indicator are normal.

[0327] Testing and evaluation criteria:

[0328] When the load current is 5A, the recording, alarm and data transmission functions of the distribution fault indicator should be normal.

[0329] In order to solve the problem of incomplete performance of power distribution fault indicators, this application has developed a power distribution fault indicator performance detection device based on a power distribution physical simulation platform, and proposed a corresponding detection method. The main technical key points and protection points are as follows:

[0330] 1) Through the power distribution physical simulation platform, various grounding, short-circuit faults and normal operating conditions are simulated realistically. The 10kV simulation line reserves the installation position of the power distribution fault indicator, and realizes the function of detecting the fault location accuracy and small current power supply capability of the power distribution fault indicator. The platform simulates the real 10kV fault and operating conditions, so it is suitable for the performance detection of various principles and types of power distribution fault indicators.

[0331] 2) Propose test items, test steps and test evaluation standards for the performance detection of power distribution fault indicators.

[0332] It should be noted that, in this article, relational terms are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of more restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the process, method, article or device including the elements. The orientation or positional relationship indicated by the terms "upper", "lower", etc. is based on the orientation or positional relationship shown in the accompanying drawings, only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. Unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0333] In the description of the present invention, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of the present description. Similarly, it should be understood that in order to simplify the disclosure of the present invention and help understand one or more of the various inventive aspects, in the above description of the exemplary embodiments of the present invention, the various features of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, the disclosed method should not be interpreted as reflecting the following intention: the claimed invention requires more features than the features explicitly stated in each claim. More specifically, as reflected in the claims, the inventive aspects are less than all the features of the single embodiment disclosed above. Therefore, the claims following the specific embodiment are hereby expressly incorporated into the specific embodiment, wherein each claim itself is a separate embodiment of the present invention. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present invention is not limited to any single aspect, nor to any single embodiment, nor to any combination and / or permutation of these aspects and / or embodiments. Furthermore, each aspect and / or embodiment of the present invention may be used alone or in combination with one or more of the other aspects and / or embodiments thereof.

[0334] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A physical simulation platform for power distribution fault indicator detection, characterized in that: include: 380V system and 10kV system; The 380V system includes: a fault generator, a 380V bus and a simulation line connected to the 380V bus, the simulation line includes a 10kV system access point connected in sequence, a parameter unit for simulating the corresponding simulation line-to-ground capacitance and a load unit for simulating the user load, and a fault access point is also provided on the simulation line; the fault access point is used to connect the fault generator; The 10kV system comprises a high-voltage feeder unit for connecting a power distribution fault indicator, the high-voltage feeder unit being connected to the 10kV system access point to perform performance detection on the power distribution fault indicator based on the 380V system; The physical simulation platform for power distribution fault indicator detection also includes: a neutral point unit, which is connected to the 380V busbar via a grounding transformer; the neutral point unit includes a first resistor, a second resistor and an arc suppression coil connected in parallel, and the resistance values ​​of the first resistor and the second resistor are different; The physical simulation platform for detecting power distribution fault indicators also includes: a capacitance parameter unit; the capacitance parameter unit includes a first capacitance-to-ground simulation subunit and a second capacitance-to-ground simulation subunit; the first capacitance-to-ground simulation subunit includes three first capacitance branches, each of which is connected one-to-one to the three-phase line of the 380V bus; each of the first capacitance branches includes a capacitor, a switch and an isolating switch connected in sequence; the second capacitance-to-ground simulation subunit includes three second capacitance branches, each of which is connected one-to-one to the three-phase line of the 380V bus; each of the second capacitance branches includes a capacitor and an isolating switch connected in sequence; the capacitors in the capacitance parameter unit are all grounded.

2. The physical simulation platform for power distribution fault indicator detection according to claim 1, characterized in that: The high-voltage feeder unit comprises: an access point, a switch, a step-up transformer, a first fuse and a 10kV feeder connected in sequence, and the high-voltage feeder unit further comprises: a current transformer, a second fuse and a voltage transformer connected in sequence to the 10kV feeder, the primary side of the voltage transformer is grounded, and the secondary side of the voltage transformer is connected to the second fuse; The 10kV feeder is used to connect the power distribution fault indicator; The access point is connected to the 10kV system access point.

3. The physical simulation platform for power distribution fault indicator detection according to claim 1, characterized in that: The fault generator comprises: a ground fault unit; The ground fault unit includes: a ground fault access point, a main switch, an arc ground fault switch, a metal and resistance ground fault switch, a first ground resistance unit and a second ground resistance unit; The ground fault access point, the main switch, the arc ground fault switch and the second ground resistance unit are connected in sequence, the metal and resistance ground fault switch is connected in parallel with the arc ground fault switch, and the arc ground fault switch and the metal and resistance ground fault switch are both connected to the first ground resistance unit; The ground fault access point is used to connect to the fault access point.

4. The physical simulation platform for power distribution fault indicator detection according to claim 3, characterized in that: The first grounding resistor unit comprises: a first grounding resistor branch, a second grounding resistor branch, a third grounding resistor branch and a fourth grounding resistor branch connected in parallel, and the first grounding resistor branch, the second grounding resistor branch, the third grounding resistor branch and the fourth grounding resistor branch are all grounded; Wherein, the first grounding resistance branch includes a switch, and the second grounding resistance branch to the fourth grounding resistance branch each include a switch and a resistor connected in series; Each of the switches in the first grounding resistance unit is connected to an arc grounding fault switch and a metal and resistance grounding fault switch.

5. The physical simulation platform for power distribution fault indicator detection according to claim 3, characterized in that: The second grounding resistance unit comprises: a grounding resistance branch, three grounding resistors sequentially connected to one side of the grounding resistance branch, and the grounding resistance branch comprises a resistor and a switch connected in series; The other side of the grounding resistance branch is connected to an arc grounding fault switch and a metal and resistance grounding fault switch; The grounding resistance branch is connected in parallel with a switch, a branch consisting of the grounding resistance branch and an adjacent resistor is connected in parallel with a switch, and another branch consisting of the grounding resistance branch and two adjacent resistors in sequence is connected in parallel with a switch.

6. The physical simulation platform for power distribution fault indicator detection according to claim 1 or 3, characterized in that: The fault generator comprises: a short circuit fault unit; The short-circuit fault unit comprises: a phase power selection switch and three short-circuit branches, and one side of each short-circuit branch is provided with a short-circuit fault access point, and the other side is sequentially connected to a switch and a resistor; each of the short-circuit branches is respectively connected in parallel to a corresponding branch consisting of a switch and a resistor connected to each other; The phase power selection switch is arranged between one side of each short-circuit branch and the corresponding short-circuit fault access point; Each of the resistors in the short-circuit fault unit is grounded via a switch; The short-circuit fault access point is used to connect to the fault access point.

7. The physical simulation platform for power distribution fault indicator detection according to claim 1, characterized in that: The simulation circuits each include three simulation branches, and each simulation branch is connected one-to-one to the three-phase line of the 380V busbar.

8. The physical simulation platform for power distribution fault indicator detection according to claim 7, characterized in that: The parameter unit comprises: at least one grounding capacitor subunit, each grounding capacitor subunit comprises three grounding capacitor branches, and each of the grounding capacitor branches is connected one-to-one to each of the analog branches; Each of the grounding capacitor branches is provided with capacitors and switches connected to each other, and each capacitor in the grounding capacitor subunit is grounded.

9. The physical simulation platform for power distribution fault indicator detection according to claim 7, characterized in that: The load unit comprises: a first load subunit and a second load subunit; The first load subunit comprises: three first load branches, and each of the first load branches is connected to each of the simulation branches one by one; each of the first load branches is provided with a switch and a resistor connected to each other; The first load subunit comprises: three second load branches, and each of the second load branches is connected to each of the simulation branches one by one; Each of the second load branches is provided with a switch, and the switches in each of the second load branches are respectively connected to the corresponding resistor or are all connected to a start button.

10. The physical simulation platform for power distribution fault indicator detection according to claim 1, characterized in that: Also includes: A 380V power supply is connected to the 380V busbar via an isolation transformer.

11. The physical simulation platform for power distribution fault indicator detection according to claim 1, characterized in that: Also includes: Two 380V bus voltage transformers are both connected to the 380V bus.

12. The physical simulation platform for power distribution fault indicator detection according to claim 1, characterized in that: The 380V busbar is connected with a fault access point and a transfer type arc extinguishing device; The transfer type arc extinguishing device comprises three grounded switches connected in parallel, and each of the switches in the transfer type arc extinguishing device is connected one-to-one to the three-phase lines of the 380V busbar.

13. A method for detecting a power distribution fault indicator, characterized in that: The power distribution fault indicator detection method is implemented using the physical simulation platform for power distribution fault indicator detection according to any one of claims 1 to 12, and the power distribution fault indicator detection method comprises: Connecting a high-voltage feeder unit provided with a power distribution fault indicator to the 10kV system access point, and connecting the fault generator to the fault access point; The 380V system is controlled to simulate fault conditions and non-fault conditions, and a performance test result of the power distribution fault indicator is determined according to the operating state of the power distribution fault indicator, wherein the performance test result includes at least one of fault location, low current power supply and false alarm detection results.

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