CN108169610A - A kind of one-phase earthing failure in electric distribution network test method based on Real Time Digital Simulator - Google Patents

Abstract

The invention discloses a kind of one-phase earthing failure in electric distribution network test methods based on Real Time Digital Simulator; it is emulated by the Real-time modeling set to true distribution network structure structure, electric parameter, relay protection, load, fault model; the wave character of electrical quantity when one-phase earthing failure in electric distribution network occurs is simulated, builds singlephase earth fault test platform.The present invention method can it is convenient, flexible, comprehensively the Specifications of terminal single-phase earthing positioning function are tested, have higher actual application value.

Description

A single-phase-to-earth fault test method for distribution network based on real-time digital simulator

technical field

The invention belongs to the technical field of power distribution automation, and in particular relates to a method for testing a single-phase grounding fault of a power distribution network based on a real-time digital simulator.

Background technique

According to statistics, the probability of single-phase ground faults in distribution networks is the highest. At present, there are many mature algorithms for single-phase ground fault section location, and many manufacturers have also begun to develop terminals or terminals with single-phase ground fault section location functions Devices such as fault indicators. However, there is little research on the detection method of the single-phase-to-ground fault location function of the power distribution terminal device.

In the early stage of the development and on-site implementation of the single-phase grounding positioning function of power distribution, effective and reliable test methods are needed to verify the function and performance of the single-phase grounding positioning function under different neutral point grounding methods, different grid structures, and different operating modes index. This has always been a difficult problem. The usual testing methods include: building a physical testing system based on relay protection testers and distribution terminals. This method is simple and fast, but it cannot simulate the real distribution network, and the characteristics of single-phase ground faults cannot be flexibly configured; One approach is to install distribution terminals on the distribution network site and use grounding equipment to generate single-phase ground faults. This method can ensure the real characteristics of single-phase ground faults, but it requires a lot of labor costs, and it is easy to cause distribution faults. safety hazards of the power grid. It can be seen that the traditional test method has many limitations, and cannot well verify the fault handling logic and related performance of the single-phase grounding positioning function. Adverse effects of promotion. There is also a single-phase grounding simulation based on Simulink and Matlab platform. By establishing a 10kV distribution network simulation model, a single-phase grounding fault is simulated, but it often cannot meet the test requirements of the device.

Contents of the invention

In view of the above problems, the present invention proposes a real-time digital simulator-based test method for single-phase ground faults in distribution networks, which can effectively and accurately simulate the characteristics of single-phase ground faults in distribution networks, and build a single-phase ground fault simulation platform through terminals and RTDS The single-phase ground fault location function test system solves the difficult problem of terminal single-phase ground fault location function test.

Realize above-mentioned technical purpose, reach above-mentioned technical effect, the present invention realizes through the following technical solutions:

A method for testing a single-phase-to-earth fault in a distribution network based on a real-time digital simulator is characterized in that it comprises the following steps:

(1) Simulate distribution network topology, operation mode and line flow in real-time digital simulator;

(2) Analog power protection logic;

(3) Simulate the single-phase ground fault control logic to generate the final RTDS distribution network model;

(4) Connect the RTDS distribution network model with the single-phase grounding terminal of the distribution network, and conduct the single-phase grounding fault test of the distribution network.

A kind of distribution network single-phase ground fault test method based on real-time digital simulator, it is characterized in that: described step (1) is specifically: according to distribution network system zero-sequence parameter model, in real-time digital simulator Simulate the distribution network system where the neutral point is not grounded, the neutral point is grounded through the arc suppression coil, and the neutral point is grounded through a small resistance, and configure the required grid parameters.

The above-mentioned method for testing a single-phase-to-ground fault in a distribution network based on a real-time digital simulator is characterized in that: the required network parameters include: line parameters, power supply parameters, transformer parameters and load parameters.

The described method for testing a single-phase-to-ground fault in a distribution network based on a real-time digital simulator is characterized in that: the power supply protection logic is: when a fault trigger signal is detected and there is indeed an overcurrent in the line, a fault alarm signal is generated , after the trip delay time is set, a trip signal is issued;

The process of reclosing is as follows: After overcurrent tripping, reclosing is performed once after the reclosing delay time is set, and if overcurrent is detected again, the trip will be accelerated.

The described method for testing a single-phase-to-ground fault in a distribution network based on a real-time digital simulator is characterized in that: the single-phase-to-ground fault control logic is:

When the voltage crosses zero, trigger the fault signal, start the phase voltage phase setting, and output the corresponding single-phase Ground fault signal.

The described method for testing a single-phase ground fault in a distribution network based on a real-time digital simulator is characterized in that: the connection method between the RTDS distribution network model and the single-phase ground terminal of the distribution network is: the RTDS distribution network model The telemetry signal is connected to the single-phase grounding terminal of the distribution network through the power amplifier through the GTAO interface; the remote signaling signal of the RTDS distribution network model is connected to the single-phase grounding terminal of the distribution network through the GTDO interface; the remote control signal of the RTDS distribution network model is connected through the GTDI The interface is connected to the single-phase grounding terminal of the distribution network.

Beneficial effects of the present invention:

A real-time digital simulator-based test method for single-phase ground faults in distribution networks proposed by the present invention can effectively and accurately simulate the characteristics of single-phase ground faults in distribution networks, and build single-phase ground faults through terminals and RTDS single-phase ground simulation platforms The fault location function test system can well solve the difficult problem of terminal single-phase ground location function test.

Description of drawings

Fig. 1 is the flow chart of the distribution network single-phase ground fault test method based on real-time digital emulator of an embodiment of the present invention;

Fig. 2 is the RTDS topology model of an embodiment of the present invention;

Fig. 3 is a flow chart of implementing power supply protection logic in an embodiment of the present invention;

Fig. 4 is a flow chart of realizing single-phase-to-ground fault control logic in an embodiment of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention more clear, the present invention will be further described in detail below in conjunction with the examples. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

The application principle of the present invention will be described in detail below in conjunction with the accompanying drawings.

As shown in Figure 1, a single-phase-to-ground fault test method for distribution network based on real-time digital simulator includes the following steps:

Step 1. Simulate the distribution network topology, operation mode and line flow in a real-time digital simulator;

As shown in Figure 2, it is a simulated neutral point ungrounded distribution network system, and the specific parameters are:

1) The line adopts a 10kv overhead cable hybrid line, the tower height is 13m, the cross-sectional area of the conductor is 185mm ² , the distance between the conductor lines is 0.85m, and the DC resistance of the conductor is 0.1592Ω/km;

2) The neutral point grounding method of the distribution network adopts arc suppressing coil and neutral point ungrounded.

3) The capacity of distribution transformer is set to 0.9MVA;

4) The load model is balanced load;

5) 31, 312 and 32, 322 are switches on branch 1 and branch 2 respectively, denoted as BRKB31, BRKB312, BRKB32, BRKB322;

6) The phase current and zero sequence current corresponding to switch BRKB31 are IBRKB31A, IBRKB31B, IBRKB31C and IBRKB31O;

7) bus means bus, and its phase current and zero-sequence current are expressed as IBRKbusA, IBRKbusB, IBRKbusC and IBRKbusO;

8) N0 is the source outlet voltage; N1, N2, N3 and N4, N5, N6 are the voltages of branch 1 and branch 2 respectively; N1A, N1B, N1C represent the ABC three-phase voltage of N1;

(2) Analog power protection logic;

As shown in Figure 3, the power supply protection logic is specifically:

When a fault trigger signal is detected and there is an overcurrent in the line, a fault alarm signal is generated, and a trip signal is issued after the trip delay time is set;

The process of reclosing is as follows: After overcurrent tripping, reclosing is performed once after the reclosing delay time is set, and if overcurrent is detected again, the trip will be accelerated.

(3) Simulate the single-phase ground fault control logic to generate the final RTDS distribution network model;

As shown in Figure 4, a small cross-current has little effect on the non-fault lines of the distribution network. Therefore, according to the parameters of the distribution network, the single-phase ground fault control logic is simulated. When the voltage crosses zero, the fault signal is triggered and then starts Phase voltage and phase setting, and output the corresponding single-phase ground fault signal according to the delay or duration of the first fault, the duration of the second fault, the type of single-phase ground fault, ground resistance, and fault location information.

(4) Connect the RTDS distribution network model with the single-phase grounding terminal of the distribution network, and conduct the single-phase grounding fault test of the distribution network;

Specifically, the connection method between the RTDS distribution network model and the single-phase grounding terminal of the distribution network is as follows: the telemetry signal of the RTDS distribution network model is connected to the single-phase grounding terminal of the distribution network through the GTAO interface through a power amplifier; The remote signaling signal of the model is connected to the single-phase grounding terminal of the distribution network through the GTDO interface; the remote control signal of the RTDS distribution network model is connected to the single-phase grounding terminal of the distribution network through the GTDI interface.

In summary:

A real-time digital simulator-based test method for single-phase ground faults in distribution networks proposed by the present invention can effectively and accurately simulate the characteristics of single-phase ground faults in distribution networks, and build single-phase ground faults through terminals and RTDS single-phase ground simulation platforms The fault location function test system can well solve the difficult problem of terminal single-phase ground location function test.

The basic principles and main features of the present invention and the advantages of the present invention have been shown and described above. Those skilled in the industry should understand that the present invention is not limited by the above-mentioned embodiments, and what described in the above-mentioned embodiments and the description only illustrates the principles of the present invention, and the present invention will also have other functions without departing from the spirit and scope of the present invention. Variations and improvements are possible, which fall within the scope of the claimed invention. The protection scope of the present invention is defined by the appended claims and their equivalents.

Claims (6)

1. a kind of one-phase earthing failure in electric distribution network test method based on Real Time Digital Simulator, which is characterized in that including following Step：

(1) distribution net topology, the method for operation and Line Flow are simulated in Real Time Digital Simulator；

(2) analog power relay protective scheme；

(3) singlephase earth fault control logic is simulated, generates final RTDS electricity distribution network models；

(4) connection RTDS electricity distribution network models and power distribution network single-phase earthing terminal, carry out one-phase earthing failure in electric distribution network test.

2. a kind of one-phase earthing failure in electric distribution network test method based on Real Time Digital Simulator according to claim 1, It is characterized in that：The step (1) is specially：According to distribution network system Zero sequence parameter model, the mould in Real Time Digital Simulator Intend the distribution network system of isolated neutral, neutral by arc extinction coil grounding and Neutral Point Through Low Resistance, and be configured Required electrical network parameter.

3. a kind of one-phase earthing failure in electric distribution network test method based on Real Time Digital Simulator according to claim 2, It is characterized in that：The required electrical network parameter includes：Line parameter circuit value, power parameter, transformer parameter and load parameter.

4. a kind of one-phase earthing failure in electric distribution network test method based on Real Time Digital Simulator according to claim 1, It is characterized in that：The power protection logic is：

When detecting false trigger signals and circuit is there are during overcurrent, fault alarm signal is generated, delay time is set by tripping It postpones, sends out trip signal；

Reclosing realizes that process is：It after overcurrent tripping, is set by reclosing delay time, single shot reclosing is carried out, if again Detect overcurrent, then rear Accelerated trip.

5. a kind of one-phase earthing failure in electric distribution network test method based on Real Time Digital Simulator according to claim 1, It is characterized in that：The singlephase earth fault control logic is：

In voltage over zero, fault-signal is triggered, when starting the setting of phase voltage phase, and being delayed or continue according to primary fault Between, the secondary failure duration, singlephase earth fault type, ground resistance, fault location information, export corresponding single-phase earthing Fault-signal.

6. a kind of one-phase earthing failure in electric distribution network test method based on Real Time Digital Simulator according to claim 1, It is characterized in that：The RTDS electricity distribution network models are with power distribution network single-phase earthing terminal coupling method：RTDS electricity distribution network models Telemetered signal is connected by GTAO interfaces through power amplifier with power distribution network single-phase earthing terminal；The remote signalling of RTDS electricity distribution network models Signal is connected by GTDO interfaces with power distribution network single-phase earthing terminal；The remote signal of RTDS electricity distribution network models passes through GTDI interfaces It is connected with power distribution network single-phase earthing terminal.