构网型变流器对交流系统低频振荡的影响分析与阻尼控制  

Impact Analysis and Damping Control of Grid-forming Converter for Low-frequency Oscillation of AC System

作　　者：薛翼程 张哲任[1] 徐政[1] 黄莹[1] XUE Yicheng;ZHANG Zheren;XU Zheng;HUANG Ying(College of Electric Engineering,Zhejiang University,Hangzhou 310027,China)

机构地区：[1]浙江大学电气工程学院,浙江省杭州市310027

出　　处：《电力系统自动化》2023年第16期103-113,共11页Automation of Electric Power Systems

基　　金：中国南方电网有限责任公司科技项目(构网型变流器及通用控制装置研制,GDKJXM20212057)。

摘　　要：构网型变流器的控制环会影响交流系统的低频振荡模态,并且不同构网型控制策略的影响机理差异明显。为了研究不同构网型控制策略对交流系统低频振荡的影响,文中针对模块化多电平变流器,建立了同步机并联构网型变流器供电系统的阻尼转矩分析模型。基于此模型,对比分析了采用虚拟同步机控制、下垂控制和幅相控制的变流器典型控制回路对系统阻尼转矩分量的影响,并利用频率响应法揭示了主导控制环引发振荡失稳的机理。最后,利用所提模型研究了构网型变流器的关键控制回路改造方案,以提升系统阻尼。基于PSCAD/EMTDC开展电磁暂态仿真,验证了所提模型在机理分析和阻尼控制设计方面的有效性。The control loops of grid-forming(GFM) converters affect the low-frequency oscillation(LFO) mode of the AC system,and the influence mechanism of different GFM control strategies are obviously different.Focusing on the modular multilevel converters(MMCs),this paper establishes a damping torque analysis model for the paralleled system with synchronous generators and GFM converters,to study the impact of different GFM control strategies on the LFO of AC systems.Based on the model,this paper studies the influence of typical control loops of the converters using virtual synchronous generator(VSG) control,droop control,and magnitude-phase control on the damping torque component of the system.Meanwhile,the oscillation instability mechanism induced by the dominant control loops is explained by using the frequency response method.Finally,the modification method for the critical loop of GFM converters is analyzed by using the proposed model for system damping improvement.The electromagnetic transient simulation is performed in PSCAD/EMTDC to verify the effectiveness of the proposed model in theoretical analysis and the damping control design.

关 键 词：新型电力系统 新能源 构网型变流器 同步稳定性 转矩分析法 振荡抑制 虚拟同步机 下垂控制 幅相控制 

分 类 号：TM712[电气工程—电力系统及自动化] TM46