A Grid of Microgrids

几十年来，微电网一直在向世界各地的岛屿和偏远村庄等与世隔绝的社区供电，主要基于柴油发电机组。因此，这些电网是众所周知的系统，具有经过良好开发和测试的组件、特性、运营策略、控制、经济和政策。然而，在过去的几年里，微电网有了快速和重大的发展，从根本上和整体上影响着这些系统。这些变化的主要动机和背后的原因是多方面的。主要驱动力之一是需要充分整合快速发展的分布式发电(DG)，特别是在可再生资源与电力转换器接口供电的情况下，高能源成本和较低的分布式发电价格(特别是风力涡轮机和太阳能光伏)，以及减少温室气体(GHG)排放和对化石燃料依赖的激励措施。德国的情况就是如此，那里的屋顶太阳能光伏电池板很普遍，默认情况下导致并网式微电网变得越来越普遍，亚利桑那州、夏威夷和澳大利亚的情况也是如此，这些地区的电力成本与太阳能光伏电池板的部署成本相比相对较高，导致许多客户安装了这些系统。在这种背景下，微电网可以将分布式和绿色能源资源与当地和区域电网整合起来，从而通过清洁能源系统满足需求，特别是加拿大和美国北极和北部社区的偏远社区微电网，那里的柴油发电机组正在被风能和太阳能光伏发电机加上电池取代。

Microgrids have been supplying electricity for decades to isolated communities such as islands and remote villages throughout the world, mostly based on diesel generator sets. Hence, these grids are well-known systems, with well-developed and -tested components, characteristics, operating strategies, controls, economics, and policies. However, in the past few years, there have been rapid and significant developments in microgrids, which are radically and holistically affecting these systems. The main motivations for and reasons behind these changes are manifold. One of the main drivers is the need to adequately integrate rapidly developing Distributed Generation (DG), especially if powered by renewable resources with power converter interfaces, fueled by high energy costs and reduced DG prices, especially wind turbines and solar PV, plus incentives to reduce Greenhouse Gas (GHG) emissions and dependency on fossil fuels. This is the case of Germany, where rooftop solar PV panels are widespread, leading by default to grid-connected microgrids becoming more common, as well as in Arizona, Hawaii, and Australia, where the relatively high costs of electricity compared to the costs of deploying solar PV panels, has led many customers to install these systems. In this context, microgrids are allowing to integrate distributed and green energy resources with local and regional grids and thus supply demand through clean energy systems, which is especially the case of remote community microgrids in Arctic and Northern communities in Canada and the US, where diesel generator sets are being replaced by wind and solar PV generators plus batteries.