能源互联网中自能源的孤岛控制研究

An Islanding Control Strategy Research of We-Energy in Energy Internet

在多自能源(we-energy,WE)并联运行的能源互联网中,传统的下垂控制因受线路阻抗的影响,难以实现无功功率的合理分配以及系统的输出电压和频率的合理限定,为此提出了基于指数的改进型下垂控制。通过讨论功率与电压、频率的关系,分析得到自能源输出的无功功率实现按比例分配的前提条件,并在此基础上采用基于指数的下垂控制对自能源输出的无功功率和电压、有功功率和频率进行控制。运用小信号分析证明了所提控制方法的稳定性,并对该策略分别在线路阻抗不平衡、自能源容量不同和采用传统下垂控制与指数下垂控制的混合系统中进行仿真和实验。仿真和实验结果验证了该策略的正确性和可行性。

In energy internet combined with more we-energies （WE）, the reactive power of the traditional droop control often deteriorates due to its dependence on the line impedances. What’s more, the output amplitude and frequency of the voltage are difficult to be limited in a reasonable range. Thus, this paper proposed an improved droop control strategy based on exponential function. According to the relationship between power and voltage, frequency, the premise condition that the reactive power of WE can achieve proportional distribution had been analyzed and an exponential droop control was proposed to improve reactive power sharing. Using small signal modeling analysis shows that the stability of the proposed control method. In the end, the simulations including line impedance imbalance, the different capacity of We-Energies and the hybrid control combined with traditional droop control and exponential droop control were studied, and simulation and experimental results were presented to validate the effectiveness of the proposed method.