基于阻抗重塑的集中式光伏电站谐波抑制策略研究

Research on Harmonic Suppression Strategy of Centralized Photovoltaic Power Station Based on Impedance Reshaping

摘要:

受线路的阻抗以及各级变压器阻抗存在的影响，电网与集中式电站间往往会因此产生负面的交互作用，很可能导致系统的稳态性能降低，主要体现为入网电流的谐波问题。针对集中式光伏电站输出电流传输过程中的谐波放大问题，以阻抗重塑为设计思路，通过串并联虚拟阻抗，在控制策略中引入网侧电压前馈与输出电流反馈补偿环节，仿真结果显示，该策略能有效改善集中式光伏电站输出电流因受系统各阻抗影响导致的谐波问题。

Abstract:

Affected by the impedance of the line and the impedance of various transformers, the negative interactions will be often generated between the power grid and the centralized power station, and it may cause a reduction in steady-state performance of the system, which is mainly reflected in the harmonic problem of grid current. Aiming at the problem about harmonic amplification in the transmission process of output current in the centralized photovoltaic power station, and taking the impedance reshaping as the design idea, the grid-side voltage feedforward and output current feedback compensation links is introduced in the control strategy through series and parallel virtual impedance. The simulation results show that the proposed strategy can effectively improve the harmonic problem caused by the influence of various impedance of the system on the output current of centralized photovoltaic power station.