分布式潮流控制器控制保护策略研究

A control and protection strategy for a distributed power flow controller

近些年,随着波动性与间歇性新能源电源的大规模接入,具有成本效益与功能强大优势的分布式潮流控制器(Distributed Power Flow Controllers,DPFC)在国内外逐步得到关注,并有多个工程项目相继投产运行。为提高DPFC运行的安全可靠性,结合DPFC的组成结构,研究了DPFC运行时可能发生的故障类型,并构建了各故障类型对应的等效电路。基于等效电路模型,分析并提取了串联耦合变压器故障、IGBT器件故障、触发信号丢失/直流电源损坏等故障情况下DPFC装置子模块的外在表现特征。结合故障特征与DPFC的启停动作时序,提出了DPFC的保护配置方案,并提出了DPFC变压器过压、直流电容过流、直流电容过压以及直流电容失压的保护策略。基于PSCAD/EMTDC构建了含DPFC的电磁暂态模型。仿真结果表明,所提保护配置方案及保护策略可以有效兼顾DPFC多种故障保护的需求。

With the large-scale access of volatile and intermittent new energy sources,gradually increasing attention has been paid to distributed power flow controller(DPFC)technology with its cost-effectiveness and function advantages,and a number of engineering projects have been put into operation.To improve the safety and reliability of DPFC operation,combined with the structure of DPFC,this paper studies the types of faults that may occur during operation.The equivalent circuit corresponding to each fault type is constructed.Based on these,the external performance characteristics of the sub-modules of the DPFC device under fault conditions such as series coupled transformer failure,IGBT device failure,trigger signal loss/DC power supply damage,etc.,are analyzed and extracted.Combining the fault phenomenon and the DPFC start-stop action timing,a protection configuration scheme for the DPFC is developed.DPFC transformer over-voltage protection,DC capacitor over-current/over-voltage protection,as well as DC capacitor voltage loss protection strategies are proposed.The electromagnetic transient model containing DPFC is completed using PSCAD/EMTDC.Simulation results show that the protection configuration and strategy proposed can satisfy the protection requirements of DPFC.