Islanding state detection method for large-scale wind power

Abstract

The invention discloses an islanding state detection method for large-scale wind power. The islanding state detection method comprises the steps of initializing a node type table and a node connecting table; monitoring a circuit breaker tripping signal in a power grid, and updating the node connecting table according to the monitored circuit breaker tripping signal, and judging whether an islanding state is formed or not according to the updated node connecting table. The islanding detection and the anti-islanding protection are performed in the power supply side high-voltage main grid for a large-scale wind power generation system; and the islanding state detection method has the advantages of rapidness, accuracy, effectiveness, safety and stability; and meanwhile, the circuit weight is not taken into consideration by the technical scheme of the islanding state detection method, so that the anti-islanding protection action can be performed more rapidly.

Description

Technical field [0001] The invention relates to the field of anti-islanding protection for large-scale wind power generation, in particular to a detection method for islanding state of large-scale wind power generation. Background technique [0002] The island state of a large-scale wind farm (base) refers to an operating state in which some wind turbines are separated from the main grid and continue to supply power to the loads below it. In large-scale wind power generation systems, effective and timely detection of islands is of great significance to wind turbines and local loads. The principles and situations caused by large-scale wind power access to islands are different from the islands in the distribution network. Therefore, the hazards of large-scale wind power access to islands are also different from the hazards of islands in the distribution network. First of all, after large-scale wind power is connected to islands, power quality is also uncontrollable. But the more...

AI Technical Summary

Problems solved by technology

2) The unique fault characteristics of the wind turbine. The wind turbine converter generally performs current control. The wind turbine is boosted through a step-by-step transformer. The wind turbine also needs to send electric energy to the booster station through a long collector feeder. In this system There is a large reactance, the system impedance is large, and the electromagnetic environment is relatively complex. Under sudden power failure, a large transient overvoltage will be generated

3) The island system is an unstable system, and its damping is small, which will generate a large transient overvoltage

4) If the system is not powered off at the beginning of reclosing, there will be an impulse voltage, and the more serious situation is that non-synchronous reclosing occurs. At this time, a large transient overvoltage will appear

Disadvantages of this method: additional equipment is required, high implementation cost, complex operation, many certifications are required, and low economy

[0028] The paper "Distributed Power Generation Islanding Method Based on Improved Prim Algorithm" proposes a minimum spanning tree algorithm based on the Prim method for the islanding problem of the user-side low-voltage distribution network. This method does not involve the high-voltage main network on the power supply side. Anti-islanding detection, and because the line weight needs to be considered, the anti-islanding protection action delay is relatively large

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