并网换流器控制参数安全域构建方法及控制交互作用分析  

Construction Method and Control-interaction Analysis of Security Region for Control Parameters of Grid-connected Converter

作　　者：王瑾媛 刘崇茹 苏晨博 吴文传[2] 房佳姝 WANG Jinyuan;LIU Chongru;SU Chenbo;WU Wenchuan;FANG Jiashu(State Key Laboratory for Alternate Electrical Power System with Renewable Energy Sources(North China Electric Power University),Beijing 102206,China;Department of Electrical Engineering,Tsinghua University,Beijing 100084,China)

机构地区：[1]新能源电力系统国家重点实验室(华北电力大学),北京市102206 [2]清华大学电机工程与应用电子技术系,北京市100084

出　　处：《电力系统自动化》2025年第7期80-90,共11页Automation of Electric Power Systems

基　　金：国家重点研发计划资助项目(2022YFB2402704);国家电网公司科技项目(52272222001J)。

摘　　要：弱电网条件下,电力电子换流器的锁相环(PLL)与直流电压控制环之间的交互作用可能引发振荡问题。为了降低并网换流器引发的振荡风险,提出了一种控制参数安全域边界选定方法,通过研究控制带宽的相对制约关系,定量分析各控制参数对并网换流器主要控制环节之间及控制器与弱电网之间交互作用的影响规律。首先,从控制器带宽重叠区域的动态响应特性具有相似性的角度出发,建立了涵盖电网强度及各控制环节的直流电压外环闭环传递函数数学解析模型。然后,在该传递函数解析表达式的基础上,利用Nyqusit稳定判据和稳定裕度约束求解控制带宽比安全域边界。所得结果可用于指导弱电网条件下PLL和直流电压控制带宽的设计,并映射为各控制参数安全域。此外,控制参数安全域直观地反映了并网换流器的参数设置差异对系统稳定性的影响,由此指导控制参数的调节方向。最后,通过PSCAD/EMTDC仿真验证了所提方法的有效性及准确性。The interaction between the phase-locked loop(PLL) and the DC voltage control loop of a power electronic converter under weak grid conditions may trigger oscillations.In order to reduce the risk of oscillation caused by the grid-connected converters,a method for determining the boundary of the security region for the control parameter is proposed.By studying the relative constraint relationship of the control bandwidth,the influence law of each control parameter on the interaction between the main control links of the grid-connected converter and between the controller and the weak grid is quantitatively analyzed.First,from the perspective that the dynamic response characteristics of the overlapped region of the controller bandwidth are similar,a mathematical analytical expression model of the closed-loop transfer function of the outer DC voltage loop covering the grid strength and each control link is established.Then,based on the analytical expression of this transfer function,the boundary of the security region for the control bandwidth ratio is solved by using the Nyquist stability criterion and stability margin constraints.The result can guide the design of the PLL and DC voltage control bandwidths under weak grid conditions and map it to the security region for each control parameter.In addition,the security region for control parameters intuitively reflects the influence of differences in parameter settings of the grid-connected converter on system stability,thereby guiding the adjustment direction of control parameters.Finally,the effectiveness and accuracy of the proposed method are verified through PSCAD/EMTDC simulations.

关 键 词：并网换流器 安全域 控制参数 稳定性 交互 锁相环 直流电压控制 

分 类 号：TM721[电气工程—电力系统及自动化]