基于时序蒙特卡洛模拟的微电网可靠性分析

发布时间：2018-10-23 11:03

【摘要】：微电网作为智能电网的重要组成部分，，可灵活高效地利用分布式电源及储能设备，但是，其在带来节能环保的同时也带来一系列运行和控制等方面的问题。同时，这些灵活的运行方式和复杂的运行特性也给微电网的可靠性评估带来挑战。本文通过建立风电机组时序出力模型、储能时序充放电模型和微电网元件两状态模型，基于时序蒙特卡洛模拟法分别对孤岛型微电网和并网型微电网进行可靠性分析。分析孤岛型微电网的可靠性评估特性，对系统孤岛时序运行状态进行模拟，提出孤岛模式的负荷削减策略和储能运行策略。计及微电网元件状态、外界环境影响及分布式电源运行特性等因素，分析了孤岛型微电网的可靠性评估特性；负荷削减策略综合考虑了负荷重要程度及位置两方面因素，体现了微电网重要用户的用电需求；从储能平滑风电机组出力、计及风能渗透率约束以及最大程度避免负荷削减的角度，研究了孤岛型微电网中储能的三种运行策略。结果表明：计及可靠性评估特性的算法可较为准确地评估孤岛型微电网的供电能力，孤岛模式的负荷削减策略和储能运行策略对系统及负荷的可靠性影响较大。分析并网型微电网中并网与孤岛两种运行方式的生成过程，提出并网协调控制策略和新的微电网可靠性指标。计及并网型微电网元件的故障影响范围，基于网络遍历搜索分析了并网和孤岛两种运行方式的生成过程；基于外网和微电网的出力模式，提出了并网运行方式的协调控制策略；针对不同运行方式的切换和微电网的运行特性，提出了孤岛平均首次持续运行时间和运行稳定率可靠性指标以评估其供电能力。结果表明：微电网的接入能有效提高配电系统的可靠性，计及并网协调控制策略和不同运行方式的切换对并网型微电网的可靠性评估有重大价值。在微电网可靠性分析的基础上，计及风速、负荷、风能渗透率和储能容量等因素的变化对孤岛型微电网的系统可靠性指标进行灵敏度分析；研究并网型微电网可靠性指标随储能容量和储能故障率的变化规律；最后分析微电源不同接入位置对配电系统可靠性的影响。结果表明：随着风速的增加、负荷水平的降低、风能渗透率的提高和储能容量的增大，孤岛型微电网可靠性改善明显；随着储能容量的增加和故障率的降低，并网型微电网可靠性指标逐渐提高；微电源的接入位置对配电系统可靠性有一定影响，为微电网规划提供了参考依据。
[Abstract]:As an important part of smart grid, microgrid can utilize distributed generation and energy storage equipment flexibly and efficiently. However, it not only brings energy saving and environmental protection, but also brings a series of problems in operation and control. At the same time, these flexible operation modes and complex operation characteristics also bring challenges to the reliability evaluation of microgrid. In this paper, based on the time series Monte Carlo simulation method, the reliability analysis of isolated microgrid and grid-connected microgrid is carried out by establishing the time series output model, energy storage time series charge and discharge model and microgrid element two-state model. This paper analyzes the reliability evaluation characteristics of isolated microgrid, simulates the operation state of isolated island time series, and puts forward load reduction strategy and energy storage operation strategy of islanding mode. Taking into account the state of microgrid components, the external environment and the operation characteristics of distributed generation, the reliability evaluation characteristics of isolated microgrid are analyzed, and the load reduction strategy takes into account two factors, namely, the importance of load and the position of load, and so on. From the point of view of energy storage smoothing wind turbine generation, considering wind power permeability constraints and avoiding load reduction to the greatest extent, three operation strategies of energy storage in isolated microgrid are studied. The results show that the algorithm can accurately evaluate the power supply capacity of isolated microgrid, and the load reduction strategy and energy storage operation strategy of isolated island mode have great influence on the reliability of the system and load. The generation process of two operation modes of grid-connected and isolated island in grid-connected microgrid is analyzed, and the coordinated control strategy and new reliability index of microgrid are put forward. Considering the fault range of grid-connected microgrid elements, the generation process of grid-connected and isolated operation modes is analyzed based on network traversal search, and the coordinated control strategy of grid-connected operation mode is proposed based on the power generation mode of external grid and micro-grid. According to the switching of different operation modes and the operation characteristics of microgrid, the reliability index of the average island first continuous operation time and operation stability rate is proposed to evaluate its power supply capacity. The results show that the access of microgrid can effectively improve the reliability of distribution system. It is of great value to evaluate the reliability of grid-connected microgrid considering the coordinated control strategy of grid-connected network and the switching of different operation modes. Based on the reliability analysis of microgrid, the system reliability index of isolated microgrid is analyzed by taking into account the changes of wind speed, load, wind energy permeability and energy storage capacity. The variation of reliability index of grid-connected microgrid with energy storage capacity and failure rate of energy storage is studied. Finally, the influence of different access positions of micro-power supply on the reliability of distribution system is analyzed. The results show that with the increase of wind speed, the decrease of load level, the increase of wind energy permeability and the increase of energy storage capacity, the reliability of isolated microgrid improves obviously, and with the increase of energy storage capacity and the decrease of failure rate, The reliability index of grid-connected microgrid is improved gradually, and the access position of micro-power has a certain influence on the reliability of distribution system, which provides a reference for microgrid planning.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM711

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