文档介绍：摘 要
大规模发展风力发电是解决能源紧缺和环境危机的必然趋势,另一方面,大量电力电子设备的使用,给电网带来了大量的谐波。因而在风力发电系统中有效实现最大风能追踪(Maximum Power Point Tracking, MPPT),并充分发挥风力发电系统并网装置的作用进行谐波治理,可以有效提高风力发电系统的风能利用效率,并提高电网供电的电能质量。因而,本文对 MPPT 和风力发电并网滤波功能两方面的风力发电系统控制策略研究具有重要的理论和现实意义。
本文提出了一种有利于高效利用风能并改善电网电能质量的风力发电系统综合控制策略。为了研究风力发电系统的控制策略,本文首先对电励磁风力发电系统的拓扑结构进行研究分析,并根据风力机运行原理、电机理论基础,构建机组中风力机、传动系统和发电机的数学模型;利用风力发电并网系统中的 PWM(Pulse Width Modulation) 逆变器与有源电力滤波器的主电路结构一致的特点,提出一种具有有源电力滤波功能的风力发电系统并网综合控制策略,根据瞬时无功功率理论对谐波电流进行检测,并与功率信号反馈法计算得到的 MPPT 指令电流合成,使系统实现 MPPT 功率并网的同时有效的抑制谐波与补偿无功,有利于高效利用风能并改善电网电能质量。并采用预测性质的无差拍技术实现并网电流的控制,在每个采样时刻实现输出电流与指令电流完全一致, 保证综合控制策略的实现。在 Matlab/Simulink 平台搭建的风力发电系统仿真模型中实现了本文所提的风力发电系统控制策略,仿真结果表明,本文的策略 MPPT 的准确性和快速性都较高,保证有效的利用风能,并且可以有效地对谐波电流进行补偿,提高电网的电能质量。
关键词:风力发电系统;最大风能追踪;有源电力滤波;控制策略
Abstract
It is a inexorable trend for Wind Power Generation System (WPGS) to be integrated into power grid cosmically in order to cope with the shortage of energy and the crisis of environmental pollution. In the other side, power electronic equipments, which bring large amount of harmonic into grid, are used more and more implement of Maximum Power Point Tracking g (MPPT) and the filtering of harmonic can make efficient use of wind energy and improve the quality of electric power. Consequently, the study of WPGS control strategy, including MPPT and grid connected control with Active Power Filtering (APF), has theoretical and practical significance.
bination control strategy of WPGS to improve quality of power and keep the high utilization efficiency of wind energy is proposed in this thesis. The topological structure, mathematic model of wind turbine, driving system and generator are deeply investigated. A new method of MPPT is proposed based on the feedback signal method. At the same time, a new wind farm grid-connected control strategy which can realize active power filtering is proposed for harmonic administer, improving the quality of power by take full advantage of grid-connected inverter. The harmonic c