The droop control strategies can realise an autonomous power allocation among virtual synchronous generators (VSGs) that can provide the recompenses of reduced system complexity and enhanced reliability. The stability of a low-inertia microgrid can be improved by implementing a VSG, designed for the coordination between multiple variable electric vehicle (EV) based charging loads. This study mainly investigates two control schemes. Firstly, the instantaneous contribution from EV charging control for any disturbance that can provide adequate damping and inertia to a low-inertia microgrid without degradation of the battery. Secondly, the adjustment of Q – V droop control is suggested by correcting the excitation voltage of a VSG. This method can reduce the influence of line impedances and power ratings on reactive power sharing in a multi-VSGs system. Additionally, four different active and reactive power control modes of VSG are discussed to emphasise EV charging and discharging control through the VSG controller. These modes are explained through circuit and vector diagrams in direct and quadratic coordinates. The efficacy of the proposed strategies and their influence on power sharing is theoretically demonstrated and analysed. Finally, the theoretical results are validated through extensive simulation and experimental verification.

中文翻译：

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低惯量微电网下电动汽车充电站VSG的增强控制策略

下降控制策略可以实现虚拟同步发电机（VSG）之间的自主功率分配，从而可以提供降低的系统复杂性和增强的可靠性的补偿。可以通过实施VSG来提高低惯性微电网的稳定性，该VSG设计用于基于多个可变电动汽车（EV）的充电负载之间的协调。本研究主要研究两种控制方案。首先，EV充电控制对任何干扰的瞬时贡献，这些干扰可为低惯量微电网提供足够的阻尼和惯性而不会导致电池退化。其次，调整问 – V建议通过校正VSG的激励电压来进行下垂控制。这种方法可以减少线路阻抗和额定功率对多VSGs系统中无功功率共享的影响。此外，还讨论了VSG的四种不同的有功和无功功率控制模式，以强调通过VSG控制器进行的EV充电和放电控制。通过电路图和矢量图在直接和二次坐标中解释了这些模式。理论上论证了所提出策略的有效性及其对功率共享的影响。最后，通过大量的仿真和实验验证对理论结果进行了验证。