晶闸管可控移相器继电保护策略研究

Research on the Relay Protection Strategy of TCPST

中文关键词:可控移相器  电流等幅特性  差动保护  串联变压器  并联变压器

keywords:thyristor controlled phase shifting transformer （TCPST）  the current equal-amplitude characteristic  differential protection  series transformer  shunt transformer

中文摘要:基于晶闸管可控移相器的拓扑与等值电路，推导得出其正常运行时的电流等幅特性。基于等幅特性提出幅值差动保护判据，根据磁链平衡原理提出了串联变压器和并联变压器差动保护判据，基于基尔霍夫电流定律提出可控移相器绕组差动保护判据，并构建了可控移相器主保护策略。分析了旁路开关偷合和晶闸管控制回路故障异常工况下的暂态特性，制定了针对异常工况保护策略，以及绕组过压过流后备保护配置方案，各保护范围相互重叠，构成了可控移相器继电保护策略。仿真模拟了不同位置故障，仿真结果表明，所配置的可控移相器继电保护策略均可有效反应可控移相器区内可能发生的各种类型故障，从而验证了该保护策略的完备性和有效性。

Abstract:Based on the topology and equivalent circuit of thyristor controlled phase shifting transformer（TCPST）， the current equal-amplitude characteristic of TCPST during normal operation is derived in this paper. The differential protection criterion based on the amplitude characteristics is proposed. Differential protection criteria for series transformers and shunt transformers are proposed based on the principle of flux balance. The differential protection criterion for the TCPSD windings is proposed based on Kirchhoff’s Current Law， and thereby the main protection strategy for the controllable phase shifter is established. Furthermore， the transient characteristics under abnormal conditions such as unauthorized closing of the bypass switch and thyristor control circuit faults are analyzed and protection strategies for these abnormal conditions are developed， along with backup protection configurations for winding overvoltage and overcurrent. The protection ranges overlap with each other， forming a relay protection strategy for the controllable phase shifter. Simulations of faults at different locations show that the configured relay protection strategy for the controllable phase shifting transformer can effectively respond to various types of faults that may occur within the protected zone of the TCPST， thereby verifying the completeness and effectiveness of the protection strategy.