并网光热发电场振荡稳定性影响因素分析与阻尼控制器设计

Analysis of Influencing Factors and Design of Damping Controller for Grid-connected CSP Farm Oscillation Stability

文中研究具有一般网络拓扑结构的、由相同光热发电机组成的太阳光热发电场的小干扰振荡稳定性。研究表明,影响光热发电场振荡稳定性的主要因素有两个:第1个因素是单台光热发电机与电场其余部分的动态联络,它决定了影响的正负情况,即有利于稳定性还是会降低稳定性;第2个因素是光电汇集网络的拓扑与参数,它主要决定了影响的程度。所以,当第1个影响因素会降低电场稳定性、而第2个影响因素较大时,光热发电场有振荡失稳风险。文中给出的算例演示,验证了理论分析结论:由于与光热发电机励磁系统相关的振荡模式阻尼为负,光热发电场出现振荡失稳。为抑制振荡,文中提出在光热发电机励磁系统中装设阻尼控制器。阻尼控制器的结构与常规的电力系统稳定器一样,但是,设计的理念完全不同。阻尼控制器设计针对第1个影响因素进行,目标是保持第1个因素对光热发电场振荡稳定性的影响为正,从而消除振荡失稳风险。文中通过仿真算例,验证所提阻尼控制器设计的有效性。

This paper studied the small-signal oscillation stability of a concentrated solar power(CSP)farm composed of the same CSP generators with a general network topology.Researches show that there are two main factors that affect the stability of the CSP farm oscillation:the first factor is the dynamic contact between a single CSP generator and the rest of the farm,which determines the positive and negative conditions of the influence,that is,whether it is beneficial to stability or undermines stability;the second factor is the topology and parameters of the collection network,which mainly determines the degree of the influence.Therefore,when the first influencing factor reduces the stability of the farm,and the second influencing factor is larger,the CSP farm has the risk of oscillation instability.The calculation example given in the article verified the conclusion of the theoretical analysis,because the damping of the oscillation mode related to the excitation system of the CSP generator was negative,and the CSP farm had oscillation instability.In order to suppress the oscillation,this paper proposed to install a damping controller in the CSP excitation system.The structure of the damping controller was the same as that of a conventional power system stabilizer,but the design concept was completely different.The damping controller was designed for the first influencing factor,for the purpose of keeping the first factor’s influence on the oscillation stability of the CSP farm positive,thereby eliminating the risk of oscillation instability.This paper verified the effectiveness of the proposed damping controller design through simulation examples.