装GCB的发电机组起停时厂用母线电压计算

The Calculating of House Service Bus Voltage when Generators with GCB Starting or Stopping

装设发电机断路器的发电机组起停时,高压厂用母线通过主变压器和高压工作厂变从系统取得电源。此时如何计算高压厂用母线的电压调整,有关规程未做出具体规定。而高压厂用母线的电压调整范围将直接影响高压工作厂变调压方式的选择。机组起停时,高压厂用母线上仅连接机组的起停负荷,可将其视为恒功率节点;而起停负荷远小于系统容量,可将系统电压视为恒电压节点。采用电力系统稳态分析方法,便可计算出机组起停时的高压厂用母线电压调整范围。该方法成功应用于外高桥第三发电厂2×1000MW机组工程。

When generators with GCB starting or stopping, all loads will be powered by the ultra-voltage power system through the main transformer and auxiliary transformers. Under this circumstance no method is provided in related regulations to calculate the voltage vibration of high-voltage auxiliary buses. The voltage vibration range is very important for optimal designing of power plants because it will directly affect the selection of voltage adjusting type of high-voltage auxiliary transformers. In the period of generators starting or stopping, high-voltage auxiliary buses can be treated as constant power points. The capacity of starting or stopping loads is much smaller than the ultra-voltage power system which can be treated as a constant voltage point. Refer to the traditional steady-state analysis method, the voltage vibration of the auxiliary buses can be calculated. This method has been successfully used in the Waigaoqiao No. 3 power plant project （21000MW） .