摘要
该文对弱电网下基于锁相控制并网变换器的小扰动同步稳定问题进行研究。首先,以机理化揭示并网变换器同步特性为目标,通过将其和传统同步机的同步动态进行类比等效,建立适用于并网变换器同步稳定分析的类Heffron-Phillips动力学模型。进而借鉴传统电力系统低频振荡分析思路,采用复转矩系统法分析思想,将锁相环主导的同步振荡模式阻尼分为两部分:锁相环自身固有阻尼分量和弱电网下复杂控制耦合引入的附加阻尼分量,进而从阻尼特性的角度揭示弱电网下并网变换器同步稳定机理,并从影响固有或附加阻尼分量的角度,研究电网阻抗、控制器参数等因素对小扰动同步稳定性的影响。该文研究结果清晰揭示了弱电网下并网变换器同步失稳机理,并为后续同步稳定控制指明了思路。
In this paper, the small signal synchronizing stability of phase locked loop(PLL) based voltage source converter(VSC) connected to weak AC grid was studied. First, based on the synchronizing dynamic similarities analysis of PLL-based VSC and traditional synchronous generator, the generalized Heffron-Phillips model of PLL-based VSC was developed to physically depict VSC’s synchronizing dynamics. Then the small signal synchronizing stability was revealed drawing lessons from the low frequency oscillation analysis in traditional power system. Based on the employed complex torque coefficient method, the damping characteristics of synchronizing oscillation mode dominated by PLL were explored, which can be divided into two parts: the inherent damping component provided by PLL and the additional damping component induced by control interaction in weak AC grid. Based on the analysis, the influences of grid impedance and controllers’ parameters on the small signal stability were investigated from affecting the inherent and additional damping component furtherly. The analysis results not only reveal the stability mechanism but also provide research ideas for future synchronizing stability control.
作者
胡祺
付立军
马凡
纪锋
张彦
王光宇
HU Qi;FU Lijun;MA Fan;JI Feng;ZHANG Yan;WANG Guangyu(National Key Laboratory of Science and Technology on Vessel Integrated Power System(Navy University of Engineering),Wuhan 430033,Hubei Province,China)
出处
《中国电机工程学报》
EI
CSCD
北大核心
2021年第1期98-108,共11页
Proceedings of the CSEE
基金
国家自然科学基金项目(51877211)。
关键词
锁相环
小扰动同步稳定
并网变换器
弱电网
phase locked loop(PLL)
small signal synchronizing stability
voltage source converter(VSC)
weak AC grid
