柴发主电源型孤岛微电网频率优化控制方法

针对以柴油发电机(Diesel Generator，DG)为主电源的孤岛微电网,存在负荷扰动下频率波动大、动态响应慢等问题，本文提出一种改进辅助调频方法以改善系统的动态响应过程。首先，建立了柴油发电机系统的模型，分析了柴发主要参数包括转动惯量、响应延时对柴发动态过程的影响。其次，提出储能(Energy Storage System, ESS)在下垂控制的基础上，增加惯量调频的方法进行辅助调频，并给出了适用于工程应用的储能辅助调频参数设计以及储能功率裕度设计方法，并通过建立柴储并列的小信号模型分析了该系统的稳定性。最后，搭建了柴储微电网的动模试验平台，试验结果表明，应对微电网内的静止负荷或者电动机类负荷，本文所提控制策略均可以有效减小系统在动态过程中的频率波动。

Optimal control method of frequency in diesel generator based islanded microgrid

In order to solve the problems such as significant frequency fluctuation and slow dynamic response under load disturbance in islanded microgrid which has a diesel generator (DG) as the primary source, an auxiliary frequency regulation method is proposed to improve the dynamic response process of the system. Firstly, the model of diesel generator system is established to analyze the impact on transient state due to main parameters, including inertia and response delay. Secondly, the energy storage system (ESS) with auxiliary frequency regulation based on droop control is proposed, and the engineering parameter and ESS''s power margin design method are given. In addition, a small signal model of the DG-ESS system is established to prove the stability of the system. Finally, the experimental platform of DG-ESS microgrid is built, and the results verify that the proposed control strategy effectively reduces the transient frequency fluctuation under the change of static or motor load.