Analysis of Practical Microgrid Stability in the Presence of Random Events

存在随机事件时实际微电网稳定性分析

• 批准号: 1406156
• 负责人: Jonathan Kimball
• 金额: $ 30.71万
• 依托单位: Missouri University of Science and Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2018-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1406156&HistoricalAwards=false
• 关键词: Analysis; Practical; Microgrid; Stability; Presence

Analysis of Practical Microgrid Stability in the Presence of Random EventsMicrogrids are power distribution systems that are small where total generation capacity is similar to the total demand. Examples may be found in isolated villages, military bases that may or may not be connected to the surrounding power grid, and vehicles ranging from automobiles to satellites to ships. DC microgrids have also been proposed for residential applications, where a single house would be a complete system, and for telecommunications power systems. Microgrids are an enabling technology for widespread deployment of renewable energy, such as solar and wind systems. This project will apply emerging control theory concepts to microgrid stability analysis. Previous researchers have usually assumed that all loads and sources have some ability to be controlled, but in practical systems, most loads change randomly, and renewable resources are subject to weather variations. The random events could cause the microgrid to become unstable and shut down. Microgrids are essential to the expansion of renewable energy due to the distributed nature of renewable energy generation, and the improved stability analysis from this project is needed to give system operators confidence in their proper operation.The objective of this project is to analyze ac and dc microgrids using advanced techniques that apply to generic impulsive Markov jump linear systems. A Markov jump linear system (MJLS) is a system that jumps instantaneously among a set of linear dynamical systems according to a Markov process. More generically, the transitions in the discrete state could be accompanied by impulses in the continuous-time states, forming an impulsive MJLS. This is a good description for the small-signal characteristics of a microgrid. Unfortunately, generic stability results for an impulsive MJLS are few. In this project, stability results for the subset of impulsive MJLS that appropriately describes microgrids will be derived. Suitable models for both ac and dc microgrids will be derived and analyzed. The results will be parameterized by controller gains and other characteristics that are within the purview of the system designer, so that stability may be guaranteed by design. Both the discrete state, which evolves randomly, and the continuous state, which is deterministic, will be considered simultaneously. The approach will be validated with simulations and experiments. Two example microgrids, one ac and one dc, will be studied to demonstrate the ability to compose an appropriate nonlinear model, to convert it to a set of small-signal models, and to map it into the impulsive MJLS framework. The proposed impulsive MJLS study will be applicable to other dynamical systems, such as networked control systems, that fit a similar framework. Similarly, demonstrating the application of impulsive MJLS methods to microgrids may stimulate research within the power community on other applications that fit a similar structure, such as the load on a voltage regulator module (VRM).

随机事件下实际微电网稳定性分析微电网是一种总发电量与总需求相似的小型配电系统。孤立的村庄、可能与周围电网连接也可能没有连接的军事基地，以及从汽车到卫星再到船舶的各种交通工具，都可以找到这样的例子。直流微电网也被提议用于住宅应用，在那里一个单独的房子将是一个完整的系统，并用于电信电力系统。微电网是广泛部署可再生能源（如太阳能和风能系统）的一种使能技术。本项目将新兴的控制理论概念应用于微电网稳定性分析。以前的研究人员通常假设所有的负荷和源都有一定的控制能力，但在实际系统中，大多数负荷是随机变化的，可再生资源受天气变化的影响。随机事件可能导致微电网变得不稳定并关闭。由于可再生能源发电的分布式特性，微电网对可再生能源的扩张至关重要，需要从该项目中改进稳定性分析，以使系统运营商对其正确运行充满信心。这个项目的目的是分析交流和直流微电网使用先进的技术，适用于一般脉冲马尔可夫跳变线性系统。马尔可夫跳变线性系统是一种根据马尔可夫过程在一组线性动力系统之间瞬间跳变的系统。更一般地说，离散状态的跃迁可以伴随着连续状态的脉冲，形成脉冲MJLS。这是对微电网小信号特性的一个很好的描述。不幸的是，脉冲MJLS的一般稳定性结果很少。在本项目中，将推导出适当描述微电网的脉冲MJLS子集的稳定性结果。本文将推导和分析适用于交流微电网和直流微电网的模型。结果将由控制器增益和系统设计者职权范围内的其他特性参数化，因此稳定性可以通过设计来保证。同时考虑随机演化的离散状态和确定性演化的连续状态。该方法将通过仿真和实验进行验证。将研究两个示例微电网，一个交流和一个直流，以演示组成适当的非线性模型，将其转换为一组小信号模型，并将其映射到脉冲MJLS框架的能力。提出的脉冲MJLS研究将适用于其他动力系统，如网络控制系统，适合类似的框架。同样地，演示脉冲MJLS方法在微电网中的应用可能会刺激电力行业对其他适合类似结构的应用的研究，例如电压调节器模块（VRM）上的负载。