多机系统PSVR与PSS的参数协调

Coordination of PSVR and PSS parameters in multi-machine system

目的为了整体改善多机电力系统的功角和电压振荡特性,方法在包含电力系统稳定器(power system stabilizer,PSS)的多机系统中引入电力系统电压调节器(power system voltage regulator,PSVR),考虑电压振荡模式与功角振荡模式的相互影响,合理整定PSVR参数。本文首先采用相频特性分析法和根轨迹法选择PSS与PSVR的参数初值;其次以控制器的增益系数和时间常数为控制变量,系统功角振荡模式和电压振荡模式的稳定性指标为优化目标,控制器参数取值范围为约束条件,建立多机系统PSS与PSVR的参数联合优化模型;最后采用非线性规划方法求解。结果通过实际算例分析,经过协调优化PSS与PSVR参数,系统的功角振荡模式和电压振荡模式得到了改善,二者阻尼比均能达到期望水平。在8机系统中,经过优化最小阻尼功角模式的阻尼比由0.0841变为0.1029,最小阻尼电压模式的阻尼比由0.0475变为0.0911;在某实际系统算例中,优化后功角、电压振荡模式中的最小阻尼模式也均能满足阈值要求。结论在包含PSS的多机系统中引入PSVR,利用本文所提多机系统PSS与PSVR参数联合优化模型,可以整体改善系统的功角和电压振荡特性。

Objective To improve the power angle and voltage oscillation characteristics of the multi-machine power system as a whole,Methods the power system voltage regulator(PSVR)was introduced into the multi-machine power system with PSS,the interaction between voltage oscillation modes and power angle oscillation modes was considered,and PSVR parameters were set reasonably.In this paper,the initial values of PSS and PSVR parameters were set by phase-frequency characteristic analysis and root locus method respectively.Then,gain coefficients and time constants of the controllers were used as control variables,stability indices of power angle oscillation modes and voltage oscillation modes as optimization objective,and the permitted range of controller parameters as the constraint condition,the joint optimization model of PSS and PSVR parameters were established.Finally,the optimization model was solved by the nonlinear programming method.Results Through the analysis of practical examples,through coordinated optimization of PSS and PSVR parameters,the power angle oscillation modes and voltage oscillation modes of the system improved,and the damping ratio of both reached the expected level.In the 8-machine system,the damping ratio of the minimum damping power angle mode increased from 0.0841 to 0.1029,and the damping ratio of the minimum damping voltage mode increased from 0.0475 to 0.0911.In the practical system,the minimum damping mode of power angle and voltage oscillation modes could also reach the threshold value after optimizing.Conclusion Introducing PSVR into the multi-machine system with PSS,the joint optimization model of PSS and PSVR parameters proposed in this paper could improve the power angle and voltage oscillation characteristics of the system as a whole.