Power electronics converters are utilized for interconnecting distributed energy storage systems into the grid. These converters can support the stability of the power system under abnormal grid conditions. In this article, a new coordinated voltage–frequency support strategy is proposed for energy storage systems considering the reactance-to-resistance ratio of the grid impedance. Unlike conventional support schemes for transmission grids, where voltage and frequency support is decoupled, the proposed strategy considers the coupling between voltage and frequency due to the resistive characteristics of the grid impedance in low-voltage distribution grids. An advanced frequency support scheme is also developed considering both droop-based frequency support and virtual inertia control for improving frequency stability. The proposed strategy ensures a fair compensation between voltage and frequency support by utilizing an adaptive gain that is calculated online according to the short-circuit fault characteristics. Simulations and experimental tests are carried out using a laboratory setup to validate the proposed strategy.

中文翻译：

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连接到配电网的存储系统的电压-频率协调支持方案

电力电子转换器用于将分布式储能系统互连到电网中。这些转换器可以在异常电网条件下支持电力系统的稳定性。在本文中，针对储能系统，提出了一种新的电压-频率协调支持策略，该策略考虑了电网阻抗的电抗比。不同于传统的输电电网支持方案，其中电压和频率支持是分离的，由于低压配电网中电网阻抗的电阻特性，所提出的策略考虑了电压和频率之间的耦合。还开发了一种先进的频率支持方案，同时考虑了基于下垂的频率支持和虚拟惯性控制，以提高频率稳定性。所提出的策略通过利用根据短路故障特性在线计算的自适应增益来确保电压和频率支持之间的公平补偿。使用实验室设置进行仿真和实验测试，以验证所提出的策略。