基于功角同步的下垂控制型逆变器低压穿越控制策略

A Low Voltage Ride Through Control Strategy of the Droop-Controlled Inverter Based on Power Angle Synchronization

中文关键词:下垂控制型逆变器  暂态稳定性  低压穿越  功角稳定控制  输出电流限幅控制  功角同步算法

keywords:droop-controlled inverter  transient stability  low-voltage ride-through  power angle stability control  output current limiting control  power angle synchronization algorithm

中文摘要:为提高故障时下垂控制型逆变器暂态稳定性，提出一种兼顾功角稳定和故障电流限制的控制策略。为实现系统功角稳定，该策略在有功-频率控制环中嵌入功角同步算法，通过调节逆变器输出频率达成目标；针对无功-电压控制环，采用二次调节机制对电压指令值进行修正，在精准控制逆变器输出电压的同时，实现输出电流向安全阈值范围的约束。同时，分析了功角稳定控制对限制逆变器输出电流的影响，证明功角稳定控制和输出电流限幅控制存在相互配合关系。最后，通过仿真验证了所提方法的有效性。

Abstract:To enhance the transient stability of droop-controlled inverters under faults，this paper proposes a unified control strategy that simultaneously guarantees power-angle stability and keeps fault current within safety limits. In the active power-frequency loop，a power angle synchronization algorithm is introduced to adjust the inverter’s output frequency，thereby achieving power angle stability. In the reactive power-voltage loop，the output voltage command value is adjusted twice to control the output voltage of the inverter and limit the output current at the safety threshold. Meanwhile，the influence of power angle stability control on limiting the inverter’s output current is also analyzed，and it is proven that there is a coordinated interaction between power angle stability control and output current limiting control. Lastly，simulation experiments are conducted to confirm the effectiveness of the presented approach.