高压快切装置在电源切换时,会对系统产生冲击包括低电压和冲击电流,如冲击过大可能引起继电保护动作,造成切换失败。本文对电源切换过程进行了理论研究,给出了母线残压和冲击电流的数学表达式,分析了切换可能引起误动的保护的类型及其原因,同时提出了快切装置和继电保护配合的措施,可以有效减小电源切换冲击,防止继电保护误动,提高切换成功率,保证负荷供电可靠性,并以实际系统为例进行了仿真验证。
When there is a switching action, it will have the impact 6n power system including voltage sag and impulse current. And if the impact is too large, it can cause the action of the protective relaying equipments. In thispaper, the process of power transfer is theoretically studied; and the mathematical expressions for both residual voltage and impulse current are given. The paper analyzes the relay protection types likely to false operate when the power switches, as well as its reasons. Then the paper put forward some measures to make fast switch device cooperates with protective relaying. In these ways the impact of power switching will be decreased, and the false tripping of protective relaying can be prevented. Finally the success rate of power switching will be increased, and the reliability of power supply can be ensured.