大级差电源密集型电网短路电流直流分量对断路器的影响

西北电网电压级差大且电源密集易导致系统短路电流超标,常采用串联电抗器、高阻抗变压器等限流措施,但却增大了系统电抗,使短路电流直流分量衰减变慢,可能导致断路器开断失败。以新疆电网乌北区域为研究对象,基于PSASP短路模块的计算结果对大型电网进行等值简化,并在EMTP/ATP中重构简化后的等值网络。校验了EMTP/ATP的等值网络与原网络的短路电流交流分量基本一致,在此基础上定量计算短路电流直流分量对断路器的影响,若仍以短路电流交流分量校验断路器开断能力,则断路器需要留有一定的裕度。

Influence of DC Component in Short Circuit Current on Circuit Breaker in Large Voltage Difference and Power Dense Grid

Because of the large voltage differential and the dense power supply, the short circuit current of the system exceeds the standard. The current limiting measures such as series reactors and high-impedance transformers are often used, but the system reactance is increased, so that the DC component of the short-circuit current is slowed down, which may cause the breaker to break failure. In order to solve the above problems, this paper takes a certain area of the Northwest Grid as the research object, and performs the equivalent simplification of the large-scale grid based on the calculation result of the PSASP short-circuit module, and reconstructs the simplified equivalent network in EMTP/ATP. The EMTP/ATP equivalent network is verified to be basically the same as the short-circuit current AC component of the original network. On this basis, the impact of the short-circuit current DC component on the circuit breaker is quantitatively calculated. If the short-circuit current AC component is still used to verify the opened breaking capacity of the circuit breaker, the circuit breaker needs to have a certain margin.