基于改进模拟植物生长算法的PSS与直流调制的协调优化

Coordinative optimization of PSS and DC-modulation based on improved PGSA

为改善交直流系统的小干扰稳定性,研究了直流调制功能中的附加阻尼控制器和电力系统稳定器(PSS)之间的协调优化策略,并进一步改进了模拟植物生长优化算法(PGSA)用于求解优化策略。通过改进搜索步长和迭代中加入云模型理论寻找新生长点来提高算法的搜索效率和收敛速度。采用修改的4机2区域系统作为算例进行仿真,以多个运行方式下系统机电振荡模式最小阻尼比最大为目标,特征根分析和时域仿真结果证明改进PGSA能有效阻尼低频振荡并增强系统的小干扰稳定性。

An optimization strategy to coordinate the supplementary damping controller in DC-modulation and the PSS（Power System Stabilizer） of AC/DC system is researched for improving its small signal stability and an improved PGSA （Plant Growth Simulation Algorithm） is proposed to solve it.The search efficiency and convergence rate of the proposed algorithm are enhanced by improving the search step and integrating the cloud model theory into iteration to find new growth points.With the least damping ratio of electromechanical oscillation mode under different operating conditions as the objective,eigenvalue analysis and time-domain simulation are carried out for a modified four-generator two-area system as an example,and results show that the improved PGSA damps low frequency oscillation and enhances system small signal stability effectively.