Abstract The Community Micro-Grid (CMG) is a coordinated local grid area served by one or more distribution substations supported by local renewable and other distributed energy resources (DER). In an islanded mode, the CMG stability reduces due to low inertia of the equivalent system and stochastic nature of renewable energy sources (RESs). To study the frequency stability of the islanded CMG system, this paper explores the mathematical modeling aspects of different sources in the CMG and the robust control design for the community microgrid model. The robust design using a fixed structure H ∞ synthesis method has been presented to compensate for the effect of modeling uncertainty. The uncertainty in the CMG model results in parametric perturbation which degrades its performance and stability. This paper explores the existing mathematical models of CMG’s and different control techniques applied for frequency regulation. Robust controller design for CMG is proposed that can handle the stochastic input disturbances like a sudden change in power coming from solar and wind sources and also the model uncertainty that results in the parametric perturbations. The complete model is simulated using MATLAB Simulink platform and results of frequency deviation obtained by robust and PID controller are compared. The controller hardware in loop (C-HIL) validation of the robust control method for CMG has been done using a real-time controller board (DS1104). This CHIL system also implements the CMG plant-controller model and analyzes the frequency deviation against load and renewable power fluctuations. The oscillations in frequency deviation are analyzed for sudden rise or fall in the renewable power coming from the solar and wind sources. A reduction of 30% is achieved in frequency overshoot and settling time using a robust controller than the PID controller. The controller developed and implemented using H ∞ synthesis has robust stability and performance for the perturbed CMG model and also shows a better time response, unlike the PID controller.

中文翻译：

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随机太阳能和风能下社区微电网的建模和频率控制

摘要 社区微电网（CMG）是一个协调的局部电网区域，由一个或多个由当地可再生能源和其他分布式能源（DER）支持的配电变电站提供服务。在孤岛模式下，由于等效系统的低惯性和可再生能源 (RES) 的随机性，CMG 稳定性降低。为了研究孤岛 CMG 系统的频率稳定性，本文探讨了 CMG 中不同来源的数学建模方面以及社区微电网模型的鲁棒控制设计。已经提出了使用固定结构 H ∞ 综合方法的稳健设计，以补偿建模不确定性的影响。CMG 模型中的不确定性会导致参数扰动，从而降低其性能和稳定性。本文探讨了 CMG 的现有数学模型和应用于频率调节的不同控制技术。提出了针对 CMG 的稳健控制器设计，可以处理随机输入扰动，例如来自太阳能和风能的功率突然变化以及导致参数扰动的模型不确定性。使用MATLAB Simulink平台对完整模型进行仿真，并比较鲁棒控制器和PID控制器获得的频率偏差结果。CMG 稳健控制方法的控制器硬件在环 (C-HIL) 验证已使用实时控制器板 (DS1104) 完成。该 CHIL 系统还实施 CMG 电厂控制器模型，并针对负载和可再生能源波动分析频率偏差。针对来自太阳能和风能的可再生能源的突然上升或下降，分析频率偏差的振荡。与 PID 控制器相比，使用稳健的控制器可将频率超调和稳定时间减少 30%。与 PID 控制器不同，使用 H ∞ 综合开发和实现的控制器对于扰动 CMG 模型具有强大的稳定性和性能，并且还显示出更好的时间响应。