Comparative isolated island detection and protection method based on wide range information phase difference

A technology of voltage phase difference and voltage phase, applied to emergency protection circuit devices, electrical components, etc., can solve problems such as short electrical distance, insufficient effect, and isolated islands relying on local information

Active Publication Date: 2013-09-11
KUNMING UNIV OF SCI & TECH +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] The technical problem to be solved by the present invention is to overcome the traditional voltage phase mutation island detection method, which only relies on detecting the phase mutation on both sides of the switch connected to the main network at the outlet of the DG to judge the island is too dependent on the amount of local information, and directly detects the phase on both sides Sudden mutation, too short electrical distance, the effect may not be obvious enough, the action criterion is difficult to determine, and the reliability is not good enough

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  • Comparative isolated island detection and protection method based on wide range information phase difference
  • Comparative isolated island detection and protection method based on wide range information phase difference
  • Comparative isolated island detection and protection method based on wide range information phase difference

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Embodiment approach 1

[0038] Implementation Mode 1: Distributed power generation system such as figure 1 As shown, there are three distributed power sources DG in the 10kV distribution network system 1 、DG 2 and DG 3 , DG 1 is a wind turbine with a capacity of 10kW, DG 2 is a micro gas turbine with a capacity of 55kW, DG 3 It is a group of photovoltaic power generation arrays with a capacity of 10kW. At the initial moment of the system, the PCC switch is closed, and the system is in the grid-connected operation state. 1.2s moment, DG 1 The load branch at the exit fails, and the load circuit breaker trips.

[0039] against DG 1 Correlation analysis is made on the impact of the load failure at the exit on the island protection. The steps of the island detection and island protection method based on the wide-area information phase difference comparison formula are:

[0040] (1) Synchronous acquisition based on wide-area information: FTU monitors the voltage phase at each DG outlet in real ti...

Embodiment approach 2

[0045] Implementation Mode 2: If the connection line or the connection short circuit between a certain DG and PCC breaks down, or the circuit breaker at the PCC node breaks down and breaks down, the system will operate partially or completely in an isolated manner. In this case, analyze the phase difference relationship between the voltage phase at the outlet of each DG and the voltage phase at the PCC. The simulated distribution network system is the same as that in Embodiment 1, and the system is still in grid-connected operation state at the initial moment. Action phase difference threshold set by this system for 3 。 . 3s moment, DG 1 Tie breaker BL at the exit 1 When a fault occurs, it is disconnected; at 6s, DG 2 Tie breaker BL at the exit 2 When a fault occurs, disconnect; at 9s, DG 3 Tie breaker BL at the exit 3 A fault disconnection occurred.

[0046] Similarly, the steps of the islanding detection and islanding protection method based on the wide-area inform...

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Abstract

The invention relates to a comparative isolated island detection and protection method based on a wide range information phase difference, and belongs to the technical field of electrical power system protective relaying. According to the comparative isolated island detection and protection method based on wide range information phase difference, in the grid-connected operation processes of a distribution network system which includes distributed generators such as wind power generators, photovoltaic power generators and micro gas turbines, a feeder automation terminal in a power grid conducts real-time synchronous monitoring on voltage phases in the system. If the break variable of a voltage phase on an exit of the distributed generator is detected to be larger than a threshold value, the voltage phase difference between the voltage phase and a public coupling point is obtained through comparative analysis after certain time delay, the phase difference is compared with the setting threshold, the fact whether isolated island operation happens in the system is judged, isolated island protection is started in time, the distributed generator which is in an isolated island operation state is logged off the system. According to the comparative isolated island detection and protection method based on wide range information phase difference, the isolated island detection and isolated island protection are based on wide range information and emphasize on the utilization of the wide range information and the realization of the safety function, the effect is obvious, and reliability is high.

Description

technical field [0001] The invention relates to an island detection and island protection method based on wide-area information voltage phase difference comparison, and belongs to the technical field of electric power system relay protection. Background technique [0002] During the grid-connected operation of the distributed generation system including DG (Distributed Generator, referred to as DG), after it is separated from the main grid, the power in the unplanned island is unbalanced, which will inevitably lead to voltage and power in the island system. A serious deviation of the frequency may cause a series of personal and operational hazards. In order to ensure the safe and normal operation of the distributed generation system, the current DG grid-connected operation regulations generally require the use of anti-islanding detection and protection, and require that the DG equipment that appears to be operating in an isolated manner be withdrawn in a timely manner. [0...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H02H7/26
Inventor 董俊束洪春徐丙垠王敬华段锐敏龚石磊荣潇
Owner KUNMING UNIV OF SCI & TECH
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