In the Low-Voltage (LV) AC microgrids (MGs), with a relatively high R/X ratio, virtual impedance is usually adopted to improve the performance of droop control applied to Distributed Generators (DGs). At the same time, LV DC microgrid using virtual impedance as droop control is emerging without adequate power flow studies. In this paper, power flow analyses for both AC and DC microgrids are formulated and implemented. The mathematical models for both types of microgrids considering the concept of virtual impedance are used to be in conformity with the practical control of the distributed generators. As a result, calculation accuracy is improved for both AC and DC microgrid power flow analyses, comparing with previous methods without considering virtual impedance. Case studies are conducted to verify the proposed power flow analyses in terms of convergence and accuracy. Investigation of the impact to the system of internal control parameters adopted by distributed generators is also conducted by using proposed method.
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机译:在低压(LV)AC微电网(MGS)中,具有相对高的R / X比,通常采用虚拟阻抗来改善施加到分布式发电机(DGS)的下垂控制的性能。与此同时,使用虚拟阻抗的LV DC Microgrid作为下垂控制在没有足够的功率流程的情况下出现。在本文中,配制和实施了对AC和DC微电网的功率流程分析。考虑虚拟阻抗的概念的两种类型微电网的数学模型用于符合分布式发电机的实际控制。结果,对于AC和DC微电网流程分析,改善了计算精度,与之前的方法相比,不考虑虚拟阻抗。进行案例研究以验证所提出的收敛性和准确性的功率流分析。还通过使用所提出的方法进行对分布发电机采用的内部控制参数的影响的调查。
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