三相三桥臂静止无功发生器的研究

发布时间：2018-02-26 11:11

本文关键词： 无功补偿静止无功发生器无功电流检测算法控制策略空间矢量调制　出处：《西安科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：供配电系统中的非纯阻性负载需要消耗大量的无功功率。传统的无功补偿装置控制精度低、动态响应速度慢。全控性器件构成的静止无功发生器(SVG)以其响应速度快、控制灵活以及补偿效果好的优势,逐渐取代传统的无功补偿技术。本文以中性点不接地系统的三相三线制供电系统的SVG为研究对象,对SVG所涉及的无功电流检测、控制策略及空间矢量调制算法等关键技术进行了研究。主要工作内容为:(1)通过两种常用主电路拓扑结构的比较选取性能更好的电压型变流器作为SVG系统的主电路,并建立数学模型;(2)对比基于瞬时无功功率理论的p-q和ip-iq无功电流检测算法,采用以ip-iq算法为基础的无功电流检测算法。为减小ip-iq检测算法在电网电压不对称时锁相不准确造成的误差,采用了由二阶广义积分器和电压正序提取环节相结合的软锁相环替代传统锁相环,有效提高了ip-i 电流检测算法的精度。(3)以αβ坐标系下SVG的数学模型为基础,设计了基于PI控制器和准PR控制器的电压电流双闭环控制系统。并对控制系统的性能指标进行了理论分析,验证了所设计控制系统的跟踪效果和控制精度,并给出了空间矢量调制算法的工作原理和实现步骤。最后,借助Simulink仿真软件搭建了 SVG系统仿真模型,并分别在阻感性负载、阻容性负载及负载突变等工况下进行了仿真验证。仿真结果表明所研究的SVG动态无功补偿系统响应速度、跟踪效果及补偿精度良好,达到了预期效果。
[Abstract]:The non-pure resistive load in power supply and distribution system needs to consume a large amount of reactive power. The traditional reactive power compensator has low control precision and slow dynamic response speed. The static Var Generator (SVG) composed of full control devices has high response speed. The advantages of flexible control and good compensation effect gradually replace the traditional reactive power compensation technology. In this paper, the SVG of three-phase three-wire power supply system with neutral point ungrounded system is taken as the research object, and the reactive current detection involved in SVG is studied. The key technologies such as control strategy and space vector modulation algorithm are studied. The main work is: 1. By comparing the topology of two common main circuits, the voltage source converter with better performance is selected as the main circuit of SVG system. A mathematical model is established to compare p-q and ip-iq reactive current detection algorithms based on instantaneous reactive power theory. The reactive current detection algorithm based on ip-iq algorithm is adopted. In order to reduce the error caused by the inaccurate phase locking of ip-iq detection algorithm when the voltage is asymmetrical in the power network, The soft phase-locked loop, which combines the second-order generalized integrator and the voltage positive sequence extraction link, is used to replace the traditional phase-locked loop, which effectively improves the accuracy of the ip-i current detection algorithm. It is based on the mathematical model of SVG in 伪尾 coordinate system. A voltage and current double closed loop control system based on Pi controller and quasi PR controller is designed. The performance of the control system is theoretically analyzed, and the tracking effect and control precision of the designed control system are verified. Finally, the simulation model of SVG system is built with the help of Simulink simulation software, and it resists the inductive load, respectively. The simulation results show that the response speed, tracking effect and compensation accuracy of the SVG dynamic reactive power compensation system are good, and the expected results are achieved.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM761.12

【参考文献】