考虑离散调压设备动作频次的高压直流输电系统控制优化
Control Optimization of HVDC System Considering Action Frequency of Discrete Voltage Regulation Equipment
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摘要: 目前中国在运行直流工程普遍采用传统控制模式,当直流功率和电压波动时可能引起直流离散调压设备的频繁动作,直接影响了直流工程的运行可靠性。针对降低直流系统离散调压设备动作频次的技术需求,首先分析了高压直流输电系统离散调压设备动作的影响因素;基于此,考虑分接开关、交流滤波器和动态无功补偿的协调,分别对直流传统定熄弧角和定直流电压控制模式进行了改进,提出了直流运行电压在选定功率区间内随直流功率变化;然后分析了所提策略的影响,并给出了相应优化建议;最后基于直流主回路计算和电磁暂态仿真,对上述分析进行验证。结果表明,所提策略能够有效降低直流系统离散调压设备的动作频次。Abstract: At present, the traditional control mode is commonly used in China’s running HVDC projects, which may lead to frequent action of DC discrete voltage regulation equipment with a fluctuation of DC power and voltage, and directly affect the HVDC project operation reliability. In view of the technical requirement for reducing the action frequency of DC discrete voltage regulating equipment, this paper firstly analyzes the action influencing factors of discrete voltage regulation equipment. Based on this, the HVDC traditional constant extinction angle and constant DC voltage control modes are respectively improved considering the coordination of tap-changer, AC filter and dynamic reactive compensation. And DC operating voltage varies with DC power within selected power range is proposed. Then the impact of the proposed strategy is analyzed and the corresponding optimization suggestions are given. Finally, the above analysis is verified based on DC main loop calculation and electromagnetic transient simulation. The results show that the proposed strategy can effectively reduce the action frequency of DC discrete voltage regulating equipment.