基于协同控制的独立电力系统频率响应优化控制策略

Optimal control strategy for frequency response of isolated power system based on synergetic control

以传统小火电机组为主的独立电力系统由于系统低惯性和火电机组存在固有延时,导致系统动态频率稳定性差。针对此问题,提出含辅助频率优化控制器的机组协调调频方案。首先借鉴风电机组利用转子动能快速调频的思想,将独立电力系统内的部分机组改造为变速恒频机组。然后在分析变速恒频机组惯量控制调频的基础上,以控制流形动态收敛为目标,基于协同控制理论,推导了惯量控制中附加功率的控制律。最后通过配合机组惯量控制利用变速恒频机组转子动能,实现对系统频率变化的快速响应。以某工业园区的独立电力系统为例进行仿真,对比分析所提方法和其他方法下的系统频率指标,仿真结果表明:所提控制策略能快速响应系统频率波动,改善了系统频率响应特性。

Isolated power system dominated by traditional small thermal units have poor dynamic frequency stability due to the low inertia of the system and the inherent delay of the thermal unit.To solve this problem,a coordinated frequency modulation scheme with auxiliary frequency optimization controller is proposed.Some units in the isolated power system are transformed into variable speed constant frequency units based on the idea of fast frequency modulation of wind turbine using rotor kinetic energy.Then,on the basis of analyzing the frequency modulation of inertia control of variable speed constant frequency unit,the control law of additional power in inertia control is derived based on the synergetic control theory,taking the dynamic convergence of the control manifold as a target.The kinetic energy of the variable speed constant frequency rotor is used by the inertia control of the unit to realize the rapid response to the frequency change of the system.Taking an isolated power system in an industrial park as an example,the system frequency indexes under the proposed method and other methods are compared and analyzed.The simulative results show that the proposed control strategy can quickly respond to the frequency fluctuations of the system and improve the system frequency response characteristics.