应对风电机组高压脱网的继电保护策略

Relay protection methods for preventing disconnection of wind turbines from grid due to voltage rising

在数次大规模风电机组脱网事故中,部分机组脱网是由于系统电压超过了机组过电压保护定值。此类事故一定程度上暴露出风电机组和无功补偿装置电压保护定值未能合理配合的问题,为解决此问题,应协调升压站电容器组和机组过电压保护定值,通过保护时限和保护定值两方面对二者进行配合。梳理了风电场无功补偿电容器组和风电机组的过电压保护的整定原则,研究了不同工况下机组电压与升压站母线电压的关系。通过简化和推理,提出了一种机组和升压站之间电压差值的工程计算方法,可用于风电场内过电压保护的整定。最后给出了风电机组和电容器组过电压保护定值的整定原则和配合策略。

During several large-scale wind-turbine-generator （WTG） dropout accidents, part of the WTGS were tripped off because the system voltage exceeded the overvoltage protection value of WTGs. One of the problems exposed in the WTG dropout accidents is that some of the relay protections are not properly set up. In this paper, the principles of overvoltage relay protection of WTGs and capacitor banks are investigated, then a method of calculating the voltage drop on WTG’s transformers and power collection lines is given;finally, several principles to set overvoltage protection of WTGs and capacitor banks are proposed.