弱电网下考虑锁相环影响的三相并网系统相角补偿控制方法  

The Phase Compensation Control Method Considering the Effect of Phase Locked Loop for Three-phase Grid-connected System in the Weak Grid

作　　者：杨苓[1] 陈燕东[1] 陈智勇[1] 罗安[1] 周乐明[1] 周小平[1] 伍文华[1] 谢志为 YANG Ling;CHEN Yandong;CHEN Zhiyong;LUO An;ZHOU Leming;ZHOU Xiaoping;WU Wenhua;XIE Zhiwei(National Electric Power Conversion and Control Engineering Technology Research Center（Hunan University）,Changsha 410082,Hunan Province,China)

机构地区：[1]国家电能变换与控制工程技术研究中心(湖南大学)

出　　处：《中国电机工程学报》2018年第20期6099-6109,共11页Proceedings of the CSEE

基　　金：国家重点研发计划项目(2017YFB0902000);国家自然科学基金项目(51477045)~~

摘　　要：在多可再生能源发电主导的弱电网中,锁相环的带宽较大时,其引入负阻尼的频率范围也较大,导致系统的稳定性降低。减小锁相环的带宽可以提高系统的稳定性,但会对系统的动态性产生不利的影响。为此,提出一种考虑锁相环影响的三相并网系统相角补偿控制方法。该方法通过公共耦合点电压前馈来改变并网逆变器的输出导纳,维持了并网逆变器的输出导纳在系统截止频率处幅值基本不变,并增大系统的相角裕度,解决因锁相环带宽较大引起的系统不稳定问题,并保证了系统的动态响应速度。实验结果验证所提方法的有效性。In the weak grid dominated by multi renewable energy generation, as the bandwidth of the phase locked loop （PLL） is large, the frequency range of the negative damping is also great introduced by the PLL, which results in the decrease of the system stability. Though the system stability can be improved by reducing the PLL bandwidth, this will have a negative impact on the system dynamics. For this, considering the effect of PLL, the phase compensation control method was proposed for three-phase grid-connected system. The feedforward point of common coupling （PCC） voltage was introduced in this method to reshape the output admittance of the grid-connected inverter. The amplitude of the grid-connected inverter output admittance was maintained at the system cut-off frequency, and the system phase margin was increased. Meanwhile, this method not only solves the problem of the system instability due to the larger PLL bandwidth, but also ensures the system dynamic response speed. The experiment results verify the validity of the proposed method.

关 键 词：弱电网 三相LCL型并网逆变器 小扰动导纳建模 锁相环 相角补偿 稳定性 

分 类 号：TM464[电气工程—电器]