多谐波源下分布式电源并网逆变器的谐波抑制策略  

Research on Harmonic Suppression Strategy of Grid Connected Inverterunder Multi-Harmonic Sources

作　　者：杨权 梁永昌 魏建荣 刘艺林 袁志聪 Yang Quan;Liang Yongchang;Wei Jianrong;Liu Yilin;Yuan Zhicong(Dongguan Power Supply Bureau of Guangdong Power Grid Co.Ltd,Dongguan 523008 China)

机构地区：[1]广东电网有限责任公司东莞供电局,东莞523008

出　　处：《电工技术学报》2023年第11期2908-2920,共13页Transactions of China Electrotechnical Society

基　　金：广东电网有限责任公司2019年营销费资助项目(031900MY62190054)。

摘　　要：在新型电力系统背景下,大量分布式电源与负荷经过电力电子接口接入配电网,由此导致的电网电压畸变将严重威胁分布式电源的并网电流质量,并恶化对配电网中关键负荷的供电电压质量。该文首先量化分析了用户侧分布式电源本地电压谐波与并网电流谐波同时抑制的制约关系,提出一种混合谐波抑制策略,包含电压谐波反馈控制环与电网流控电压补偿环,本地电压谐波控制环基于负反馈控制减小输出谐波阻抗,而并网电流控制补偿器通过产生补偿电压等效缩小并网线路谐波导纳,从而实现分布式电源对本地负载电压谐波与并网电流谐波的协同治理;然后,建立系统的小信号模型,研究系统参数摄动对其稳定性与鲁棒性的影响;最后,通过实验验证了所提策略的有效性。Nowadays,more and more power-electronics-interfaced distributed generations(DGs)and new loads are connected to the distribution network,which endows the electricity grids superior flexibility and controllability.However,with the penetration of DGs and intensive utilization of nonlinear loads,the resulting grid distortion will seriously threaten the grid current quality of DGs and deteriorates the voltage of critical loads in the distribution network.Recently,few researches geared toward the quantitative analysis of the fundamental limitation in the dual harmonics suppression,nor the adaptability improvement of DGs in the presents of both the local nonlinear loads and distorted grid.To address these issues,this paper proposes a hybrid harmonic suppression scheme,which leads to substantially lower total harmonic distortion for both the local load voltage and the grid current at the same time.First,the constraint involved in the simultaneous elimination of distortion for both the inverter local voltage and the grid current is quantitatively analyzed.The conventional method to restrain local voltage harmonicuhs was to abate the inverter output harmonic impedance Zhovia a negative feedforward.However,the suppression of grid current harmonicihg might be compromised sinceihg is also nonlinear with Zhofrom the numerical expression.Therefore,the restriction of the two distortions entirely and simultaneously appears infeasible for the intrinsic contradiction by using one control variable Zho.Then,a hybrid harmonic suppression based on multiple harmonic sequence component observer(MHSCO)is proposed,which mainly consists of a local voltage harmonic control loop and a grid current-controlled voltage compensator.MHSCO is introduced rather than conventional DFT for the accurate and exhaustive extraction of individual harmonics simultaneously,so that individual harmonic components in grid current and local voltage are extracted respectively and with superior time-varying response characteristics.A local voltage harmonic control

关 键 词：分布式电源 非线性负载 电网背景谐波 谐波治理 并网逆变器 

分 类 号：TM464[电气工程—电器]