Abstract

Due to recent advances in power electronics, microgrids based on distributed resources with expandable electronic interfaces are expanding. One of the most common ways to share power between these resources in an islanded microgrid is to use droop control. However, due to the difference in line impedance, reactive power-sharing using this method is not accurate and leads to overload in some sources. To solve this problem, this paper presents a method based on the use of common droop characteristics and uses the potential of the virtual impedance in a distributed resource control system. The voltage droop created by the virtual impedance will increase the accuracy of the reactive power-sharing between sources. To generate the right virtual impedance, local controllers of each resource exchange the required information with the microgrid management center using a low-bandwidth telecommunication link. Then, using the droop characteristic of the virtual impedance- reactive power proposed in the resource control system, the amount of virtual impedance of each source is determined in proportion to the microgrid load and resource capacity. Due to the load changes in the microgrid, the slope of the proposed characteristic is adjusted comparatively. To confirm the efficiency of the proposed method, various scenarios have been tested in low voltage microgrid.

中文翻译：

---

基于虚拟阻抗的自适应下垂控制改善孤岛微电网中无功功率的共享

摘要

由于电力电子技术的最新进展，基于具有可扩展电子接口的分布式资源的微电网正在扩展。在孤岛微电网中这些资源之间共享功率的最常见方法之一是使用下垂控制。但是，由于线路阻抗的差异，使用此方法的无功功率共享不准确，并且会导致某些电源过载。为了解决这个问题，本文提出了一种基于常见下垂特性的方法，并在分布式资源控制系统中利用了虚拟阻抗的潜力。虚拟阻抗产生的电压降将提高电源之间无功功率共享的精度。为了产生正确的虚拟阻抗，每个资源的本地控制器使用低带宽电信链路与微电网管理中心交换所需的信息。然后，利用资源控制系统中提出的虚拟阻抗-无功功率的下降特性，与微电网负载和资源容量成比例地确定每个电源的虚拟阻抗量。由于微电网中的负载变化，建议特性的斜率将进行相对调整。为了确认所提出方法的效率，已在低压微电网中测试了各种方案。每个电源的虚拟阻抗量与微电网负载和资源容量成正比。由于微电网中的负载变化，建议特性的斜率将进行相对调整。为了确认所提出方法的效率，已经在低压微电网中测试了各种场景。每个电源的虚拟阻抗量与微电网负载和资源容量成正比。由于微电网中的负载变化，建议特性的斜率将进行相对调整。为了确认所提出方法的效率，已在低压微电网中测试了各种方案。