The control to stabilize the frequency and voltage is the main goal of controlling the islanded microgrid. The microgrid can include different inverters, which are connected in parallel to each other by lines that have different impedances. The loads in the microgrid include local and public loads. With the different line impedances and local loads, it has made the voltage and current controller-type PI (proportional integral) or PID (proportional integral derivative) unable to guarantee the stability for the microgrid, and also, the power sharing between inverters is not made accurate. In this study, an improved power sharing controller is proposed by adjusting the droop voltage slope, in order to increase the accuracy of power sharing, while the microgrid has local loads and the line impedances have significant differences for inverters connected to a microgrid. This controller is combined with a sliding mode control to improve accuracy in power sharing and improve the quality of the voltage supplied to the loads. The control model has been simulated and experimental with two inverters connected in parallel. The simulation and experimental results demonstrate the effectiveness of the proposed control method.

中文翻译：

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孤岛微电网无功功率共享的改进控制器

稳定频率和电压的控制是控制孤岛微电网的主要目标。微电网可以包括不同的逆变器，这些逆变器通过具有不同阻抗的线路相互并联。微电网中的负载包括本地负载和公共负载。由于线路阻抗和本地负载不同，使得电压电流控制器型PI（比例积分）或PID（比例积分微分）无法保证微电网的稳定性，而且逆变器之间的功率分配不做准确。在这项研究中，提出了一种改进的功率分配控制器，通过调整压降电压斜率，以提高功率分配的准确性，而微电网具有本地负载，并且线路阻抗对于连接到微电网的逆变器具有显着差异。该控制器与滑模控制相结合，以提高功率分配的准确性并提高提供给负载的电压质量。该控制模型已经通过两个并联的逆变器进行了仿真和实验。仿真和实验结果证明了所提出的控制方法的有效性。