并联型多端高压直流输电系统的控制与保护策略及仿真

多端高压直流(multi-terminal direct current,MTDC)输电系统可以实现各换流站所连交流系统之间的功率输送或电力交换,能够解决多电源供电或多落点受电的输电问题,其接线形式总体分为串联型与并联型。针对4端并联型高压直流输电系统进行稳态运行和暂态故障过程的相关研究,基于EMTDC/PSCAD平台建立单极仿真模型,完成了多种解锁起动和闭锁停运组合的仿真分析,设计了直流功率平衡控制器实现各换流站功率协调控制,并提出了单个换流站紧急停运以及直流线路故障时的控制保护配合方式,仿真结果表明了控制与保护策略的有效性。

Control and Protection Strategies for Parallel Multi-Terminal HVDC Power Transmission System and Their Simulation

Multi-terminal high voltage direct current(MTDC) power transmission system can implement power transmission or power exchange between converter stations and the AC power transmission systems connecting to the formers.It can also solve the problem of power transmission while there are multi power sources or multi receiving ends.In general,the connection patterns of MTDC can be divided into two forms,i.e.,the connection in parallel and the connection in series.In this paper,the steady-state operation and transient fault process of four-terminal parallel HVDC power transmission system are researched.Based on the platform of EMTDC/PSCAD a monopole simulation model is built to carry out the simulation on multi combinations of deblock startup with block-caused outage,and a DC power balance controller is designed to implement the coordinated power control among converter stations.Besides,a cooperation mode of the controller with the protection under emergency outage of single converter station or under fault occurred in DC transmission line is put forward,and simulation results show that the proposed control and protection strategies are effective.