Distribution network protection method taking randomness of photovoltaic power station into consideration

Abstract

A distribution network protection method taking the randomness of a photovoltaic power station into consideration mainly solves the problems that conventional distribution network protection equipment is seriously affected in protection range, selectivity, sensitivity and reliability after being accessed into a distributed power supply. The method comprises the following steps: dividing the distribution network into areas, and real-timely monitoring the current output by each area; building a dynamic Thevenin equivalent parameter model of the distributed power supply; detecting faults of the distribution network; positioning and separating the fault area; and reclosing to resume power supply. The method is not affected by the access number, capacity and positions of the distributed power supplies, such as the photovoltaic power station, can realize fault detection, fault area positioning and separating, reclosing and power supply resuming quickly and reliably, is not only suitable for the requirement of large-capacity DG injection in the future and can reliably work when large-capacity DG is injected, but also suitable for the distributed power supply with large output random variation, and has the characteristic of shorter time in cutting off instant faults.

Description

technical field [0001] The invention relates to the technical field of power system distribution network protection, in particular to a distribution network protection method considering the randomness of a photovoltaic power station. Background technique [0002] With the access of a large number of distributed power sources, the network structure of the distribution network will change from a radiating single power source to a dual power source, or even a complex topological structure where multiple power sources and loads coexist. Therefore, the protection scope and selection of the original feeder protection The performance, sensitivity, and reliability will be seriously affected, which will cause the protection device to malfunction or refuse to operate, seriously affect the safe and stable operation of the distribution network, and greatly reduce the reliability of power supply. [0003] Scholars at home and abroad have done a lot of work on the hot issue of distributi...

AI Technical Summary

Problems solved by technology

However, the operating characteristics of most distributed power sources such as photovoltaic power generation and wind power generation are significantly different from conventional power sources, and their operating parameters such as output power and equivalent impedance are affected by various uncontrollable natural conditions such as light intensity, ambient temperature and wind speed. The comprehensive influence of factors, with randomness

Therefore, the research on the protection scheme of distribution network using distributed power as a constant power source has certain limitations.

Images