考虑交流滤波器扰动的换相失败预测控制策略改进

换相失败是高压直流输电系统中最常见的故障之一,而换相失败预测控制则是预防换相失败的重要手段。文中从断路器离散动作特性和控制原理等方面,详细分析了交流滤波器投入对换相失败预测控制造成扰动的机理,并从检测定值环节分析控制策略改进的可行性。另外,为彻底解决交流滤波器投入等轻微交流系统扰动对换相失败预测控制以及高压直流输电系统的影响,分析了直流电流在交流系统扰动以及交流系统故障期间的变化特征,引入新的电气参数作为辅助判据,完善换相失败预测控制原理。仿真测试结果表明,优化后的换相失败预测控制抵御交流系统扰动的能力更强,在高压直流工程中的适用性更高,更有利于高压直流系统的稳定运行。

Improvement of commutation failure predictive control considering AC filter disturbance

Commutation failure is one of the most common faults in HVDC system, and the predictive control of commutation fail-ure is an important means to prevent commutation failure. In this paper, the disturbance mechanism caused by the AC filter to the predictive control of commutation failure is analyzed in detail from the aspects of discrete action charac-teristics and control principle of circuit breaker. And at the same time, the feasibility of control strategy improvement is also analyzed from the detection. In order to thoroughly solve the influence of slight AC system disturbance on commutation failure predictive control and HVDC transmission system, such as the input of AC filter,the characteristics of DC current variation during AC system disturbance and failure are analyzed, and the new electrical parameters are introduced as auxiliary criteria to improve the commutation failure predictive control principle. The simulation results show that, the optimized commutation failure predictive control has stronger ability to resist the disturbance of AC sys-tem, higher applicability to HVDC project, and is more conducive to the stable operation of HVDC system.