直流电网用混合式直流断路器开断参数影响因素研究

Breaking Parameter Influencing Factors of Hybrid DC Circuit Breaker Applied to DC Power Grids

直流电网中应用的开断参数是高压直流断路器研究与设计的前提条件,其影响因素的探讨对系统与设备的协同设计有重要意义。基于功能要求提取了混合式高压直流断路器的核心开断参数,从电网运行方式、系统参数、故障特性、保护配合以及断路器参数设计等多个方面对核心开断参数的影响进行了定性和定量分析。搭建了张北四端柔直电网工程和混合式直流断路器电磁暂态仿真模型,对影响因素进行了仿真验证。结果表明系统电抗器参数、接地设计、保护出口时间和断路器重合闸动作逻辑对开断参数均有不同程度的影响,通过多参数优化可有效提升系统和断路器技术经济性能。所提分析方法和分析结果为直流电网用混合式直流断路器开发和设计提供了借鉴。

The breaking parameters of High-voltage DC circuit breakers(HVDC-CBs) in DC grids are the prerequisites for the research and design of circuit breakers, and the study of its influencing factors is of great significance to the collaborative design of the system and equipment. This paper extracts the core breaking parameters of DCCBs in DC grids applications based on the principles, then the qualitative and quantitative analysis of the impact of the core breaking parameters from aspects of power grid operation modes, system parameters, fault characteristics, protection coordination and circuit breaker equipment parameters are carried out. An electromagnetic transient simulating model of ±500 kV 4-terminal VSC-based DC grids and hybrid DCCBs is built. The simulation results verify that the reactors parameters, grounding design, protection timing and reclosing action logic of DCCBs have different degrees of influence on the breaking parameters. The multi-parameter optimization will effectively improve the technical and economic performance of the system and the DCCBs. The analysis methods and results provide a reference for the design of hybrid DCCBs.