光伏电站接入对地区电网继电保护的影响及对策研究

发布时间：2018-03-20 20:09

本文选题：光伏电站　切入点：地区电网　出处：《华北电力大学》2017年硕士论文　论文类型：学位论文

【摘要】：近年来,为了应对能源和环境这两大制约人类社会发展的主要问题,各国纷纷开始寻求新的解决措施,大规模的光伏发电在此背景下应运而生。然而,大量光伏电站接入传统电网,在增加系统运行方式灵活性的同时,也增加了系统结构的复杂性,给地区电网的继电保护带来了新的挑战。本文对光伏电站接入对地区电网的继电保护的影响及对策进行了研究,论文的主要工作及取得的成果如下:首先,研究了光伏并网逆变器的控制策略,主要包括最大功率追踪控制和光伏逆变器两种常用的控制策略,一种是传统控制策略,另一种是动态无功电压支撑控制策略。其次,在DIgSILENT/Power Factory软件中建立了光伏逆变器的仿真模型,仿真研究了不同故障程度下光伏逆变器的短路电流特性;建立了光伏电站通过专用送出线路接入110k V系统的典型并网模型,仿真研究了不同短路故障类型下光伏电站故障电压电流特性和弱电源特性,同时仿真研究了不同控制策略下光伏电站送出线路两侧电流的相位特性。然后,考虑了光伏并网逆变器输出短路电流达到限幅和未达到限幅两种情况,从短路点位置、光伏电站容量和接入位置三个方面理论推导了光伏电站接入典型配电网后各处电流保护的计算公式,总结了光伏电站接入对电流保护影响的规律,仿真验证了理论分析的正确性并给出了改善方法。最后,理论分析了光伏电站接入对送出线路距离保护产生影响的原因,提出了一种利用线路两侧信息的光伏电站送出线路自适应距离保护方法,仿真验证了理论分析的正确性和所提改善对策的可行性。
[Abstract]:In recent years, in order to deal with the two major problems of energy and environment that restrict the development of human society, many countries have begun to seek new solutions, and large-scale photovoltaic power generation has come into being in this context. A large number of photovoltaic power plants are connected to the traditional power grid, which not only increases the flexibility of the system operation mode, but also increases the complexity of the system structure. This paper studies the impact of photovoltaic power station access on the relay protection of regional power network and the countermeasures. The main work and achievements are as follows: first of all, The control strategy of grid-connected photovoltaic inverter is studied, which includes two common control strategies: maximum power tracking control and photovoltaic inverter, one is traditional control strategy, the other is dynamic reactive voltage support control strategy. The simulation model of photovoltaic inverter is established in DIgSILENT/Power Factory software, the short-circuit current characteristics of photovoltaic inverter under different fault degree are simulated, and the typical grid-connected model of photovoltaic power station connected to 110kV system by special transmission line is established. The characteristics of voltage and current and weak power supply of photovoltaic power station under different short-circuit fault types are studied by simulation, and the phase characteristics of the current on both sides of the output line of photovoltaic power station under different control strategies are also simulated. When the output short-circuit current of photovoltaic grid-connected inverter reaches the limit and does not reach the limit, the short circuit position is considered. In this paper, three aspects of the capacity and access position of photovoltaic power station are discussed. The calculation formulas of the current protection after the photovoltaic power station is connected to the typical distribution network are deduced, and the law of the influence of the access of the photovoltaic power station on the current protection is summarized. The simulation verifies the correctness of the theoretical analysis and gives the improvement method. Finally, the reason of the influence of the photovoltaic power station access on the distance protection of the transmission line is analyzed theoretically. This paper presents an adaptive distance protection method for photovoltaic power transmission lines based on the information on both sides of the line. The simulation results verify the correctness of the theoretical analysis and the feasibility of the proposed improvement measures.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM615;TM77

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