集散式光伏逆变系统低电压穿越控制策略

针对集散式光伏逆变系统低电压穿越时稳定性差的问题,提出了一种低电压穿越控制策略。该策略以智能控制器和逆变器相互耦合的直流母线电压为参考量,对智能控制器和逆变器进行协调控制,实现低电压穿越时的功率平衡。并通过负序电流指令补偿,抑制电网电压不平衡时直流母线电压2次纹波。1 MW集散式光伏逆变系统LVRT试验结果表明,该方法具有良好的动态响应和稳态性能,低电压穿越时,直流母线电压控制稳定;低电压穿越恢复时,有功功率恢复平稳快速。研究成果有重要的工程应用价值。

Low Voltage Penetration Control Strategy for Central Distributed Photovoltaic System

Aiming at the poor stability of central distributed photovoltaic system under low voltage ride through (LVRT), an efficient strategy was proposed. The strategy took the DC bus voltage as the reference value to coordinate the control of smart controller and inverter to achieve power balance. The second-order DC ripple voltage caused by voltage imbalance was suppressed by negative sequence current compensation. The 1 MW central distributed photovoltaic system LVRT experiment shows that the proposed method has good dynamic response and steady-state performance. When the grid voltage drops, the DC voltage surge is small. When the grid voltage restores, the active power restores smoothly and quickly. The research results has important engineering application value.