黑启动过程中空载变压器合闸过电压及其限制措施

The Overvoltage of No-load Transformer Closing in Black Start Process and Its Restrictions

空载变压器合闸时可能产生的幅值较高、持续时间较长的谐振过电压会导致避雷器吸收能量过大而损坏。研究黑启动电源通过升压变压器带空载长线路,在空载变压器合闸时导致的过电压情况,并提出了限制合闸过电压的措施。结论为:不采取措施下进行空载变压器合闸,在绝大多数情况下金属氧化物避雷器(MOA)吸收能量超过避雷器自身的能耗允许水平;若500 kV主变压器合闸前第三绕组带上一定容量的低压电抗器,可以有效地降低空载变压器合闸过电压水平及MOA吸收能量;加载地区负荷和在主变压器断路器安装选相合闸装置对抑制空载变压器合闸过电压的效果明显。

The resonance overvoltage of high amplitude and long duration,which likely occurs in no-load transformer closing,can lead to a damage to the metal oxide arrester（MOA） as the MOA absorbs excessive energy.This paper analyzes the overvoltage of no-load transformer closing in the condition of black start source connected with no-load long line,and puts forward restrictions for it.The results show that when without any restriction,the energy consumption of MOA is more than the allowable level in no-load transformer closing;but the consumption and the overvoltage level can be effectively reduced with a measure of setting some low resistance on the tertiary winding before 500 kV amin transformer closing;the other two effective measures to restrict the overvoltage are to load regional load and to install phase selectoion making device in the circuit breaker for main transformer.