基于改进无源控制的含不平衡负载微电网电压控制策略

为解决微电网中由不平衡负载引起的三相电压不平衡问题，设计了一种基于改进的互联与阻尼配置(IDA)的无源控制(PBC)策略，考虑微电网中分布式电源之间的互联关系，建立了含不平衡负载多母线微电网并网逆变器的端口受控哈密顿模型，从系统全局能量的角度出发，通过互联与阻尼配置消除不平衡负载导致的二次谐波分量，选择合适的能量函数，保证了闭环的稳定性，实现并网输出电压电流正弦化。仿真验证结果表明，所提控制策略无需将电压/电流的正负序进行分离，使系统的控制结构简化，且与传统无源控制策略相比，所提控制策略能快速准确地控制输出电压和频率，有效降低了谐波干扰，实现了更好的动态响应。

Voltage Control Strategy of Microgrid with Unbalanced Load Based on Improved Passive Control

In order to solve the problem of three-phase voltage imbalance caused by unbalanced loads in microgrids, a passivity-based control (PBC) strategy based on improved interconnection and damping assignment (IDA) was designed. Considering the interconnection relationship between distributed power sources in microgrids, a port controlled Hamiltonian model for grid-connected inverter of multi-bus microgrid with unbalanced loads was established from the perspective of global energy systems. The second harmonic components caused by unbalanced load were eliminated through the interconnection and damping force configuration. The suitable energy function was selected to ensure the stability of the closed-loop and realize the sinusoidal output voltage current in connected grid. The simulation results show that the proposed control strategy does not need to separate the positive and negative order of voltage/current, which simplifies the control structure of the system. Moreover, compared with the traditional passive control strategy, the proposed control strategy can control the output voltage and frequency quickly and accurately, reduce the harmonic interference effectively, and achieve better dynamic response.