【摘要】 分析在直流小步长仿真过程中假设换流母线的交流电压不变对交直流系统双时步暂态稳定性仿真结果产生的影响及原因:该假设可能会延迟直流系统中一些具有开关特性的控制器的动作时间,造成仿真结果不准确;对于多馈入直流系统甚至可能引起直流开关特性控制的误动作,从而使仿真结果失真。所提出考虑直流控制器开关特性的变步长仿真方法,可正确计及直流开关特性控制的动作时间;实现传统的交直流双时步仿真方法和考虑直流开关特性控制的变步长仿真方法;通过算例证明所提出的变步长方法结果是准确的,且很好地保持了传统双时步方法的计算效率。更多还原

【Abstract】 The assumption of the AC commutating voltages being unchanged during the fast HVDC simulation can affect the results of the two-time-step transient stability simulation of the AC/DC power system. This effect and its origin are analyzed. The assumption may delay the action of some HVDC controls with switching characteristics, resulting in errors in simulation results, and may even cause misoperation of the HVDC switching controls in the case of the study of multi-infeed HVDC systems. A variable-step simulation method considering HVDC switching controls is proposed. It can make the HVDC switching controls act in time during the simulation. Both the conventional two-time-step method and the new variable-step method were implemented. Cases study shows that the proposed method can obtain a better accuracy than the conventional one, and the calculation efficiency is not eroded.更多还原