基于全过程动态仿真的受端电网中长期稳定轨迹特征及防控策略研究

Mid-Long Term Stable Trajectory Characteristics and Control Strategies of Receiving-End Grid Based on Full Dynamic Simulation

发电机过励磁限制器和有载调压变压器等慢速动态元件的动态特性是受端电网中长期动态稳定水平的关键影响因素。以环状分区运行的特大型城市电网为研究对象,分析了中长期过程中慢动态元件动作对系统运行点在系统动态PV曲线上的迁移特征及主要电气量的影响。揭示了过励磁限制和有载调压动作引起系统中长期电压失稳机理,并在此基础上定义了中长期动态稳定控制判据及裕度计算方法,提出了网源配合改善中长期稳定水平的控制策略。最后通过对北京电网的全过程动态仿真分析验证了稳定判据及控制策略的有效性。

Dynamic characteristics of slow dynamic elements such as generator over-excitation limiter and on-load tap changing transformer are key factors influencing mid-long term dynamic stability of power grid. Taking cyclic partition running large urban power grid as study object, this paper analyzed effect of long process of slow dynamic elements action on transition characteristics of operating point in dynamic system＇s PV curves and main electrical quantities and revealed mechanism of long term voltage instability in the system due to over-excitation limiter and action of on-load tap changer. Based on this, mid-long term dynamic stability criterion and stability margin algorithm were defined, and corresponding improving measures in mid-long term and stable level of control strategy were puts forward. Finally, stability criterion and validity of the control strategy were verified with whole process dynamic simulation analysis of Beijing power grid.