换流变压器第1次空载合闸励磁涌流抑制的研究

Research on Suppression of Excitation Inrush Current of Converter Transformer Caused by First No-load Closing

为了有效地抑制换流变压器(以下简称"换流变")第1次合闸产生的励磁涌流,减少高幅值励磁涌流对交流系统的冲击以及对一次设备的伤害,研制了一种断路器动作时间精确量测装置,该装置可对断路器合闸控制装置进行预控。为此,首先分析了换流变第1次空充励磁涌流的机理及断路器的动作特性,在此基础上设计并开发了高压断路器的闭环动作时间测试装置,可在一次设备调试阶段精确测量高压断路器的闭环动作时间,在换流变第1次合闸前为分相合闸装置提供有效的时间校准定值。该装置已应用于某在运换流站中,换流变第1次合闸录波数据表明,测得的断路器静态闭环动作时间在分相合闸预控时间的预期范围内,换流变第1次合闸励磁涌流也能抑制在1 A(标幺值为0.001)内。

In order to effectively suppress excitation inrush current of the converter transformer caused by the first time closing and reduce impact of high amplitude excitation inrush current on the AC system and damage to the primary equipment,this paper designs a kind of measurement device for accurately measuring action time of the circuit breaker of the converter transformer which is able to conduct pre-control of the breaker closing control device.It firstly analyzes mechanism of the first time no-load excitation inrush current of the converter transformer and action characteristic of the breaker,and then develops a testing device for closing action time of the high voltage breaker which is able to accurately measure closing action time in commissioning stage of the primary equipment and provide effective time calibration value for the split phase closing device before the first time closing of the converter transformer.This device has been used in one operating converter station.The recording data of the first time closing indicates the measured static closing action time of the breaker is in the expected pre-control time range and excitation inrush current caused by the first time closing is less than 1 A (0.001 p.u.).