特高压直流分层接入方式下阀组在线投入策略研究

Online deblocking strategies of valve group for UHVDC system under hierarchical connection mode

目前,受端分层接入技术在特高压直流工程中得到广泛运用。受分层接入影响,高低端无功分层控制、核心控制器下放至阀组层。如何优化阀组投入方式,使其成熟运用于分层接入工程中亟待研究。文中详细介绍了分层接入方式下阀组在线投入控制策略,着重指出在线投入过程中控制器切换与触发角变化的关系;通过与常规特高压直流比较,指出分层接入方式下阀组在线投入策略的新特点;通过实际建模以及试验支撑,提出阀组在线投入成功的关键步骤。现场试验结果表明,文中所提的控制策略适用于现有的特高压分层接入直流工程,分层接入逆变站在合理的时间区间内拉开阀组旁通开关可以确保阀组可靠投入。

Nowadays,the technology of the receiving end under hierarchical connection mode is widely adopted in the UHVDC project. With the affection of hierarchical connection mode,high and low-end reactive power is controlled respectively and core controller is put down to the valve group layer. How to optimize the mode of online valve group deblock and making it apply ripely into hierarchical connection mode should be explored urgently. This paper introduces the control strategy of online valve group deblock under hierarchical connection mode in detail,and points out the relationship between controller switch and trigger angle change in the process of online input. By comparing with the conventional one,it puts forward the new features of online valve group deblock strategy under hierarchical connection mode. It also indicates the key steps of online valve group deblock through the actual modeling and test support. The field test results show that the control strategy described in this paper is applicable to the existing UHVDC project under hierarchical connection mode,and the inverter station under hierarchical connection mode should open the BPS switch in a reasonable time interval to ensure the reliable operation of the valve group.