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-iq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。

Non pure resistance load in power supply and distribution system needs to consume large amounts of reactive power.Traditional methods of reactive power compensation equipped with low-accuracy and slow dynamic response shall be gradually replaced by SVG,which is composed by full-controlled devices and shares advantages of fast response,flexible control and good effect.In this paper, the key technologies of SVG, such as the reactive current detection technology,direct current control strategy, and SVPWM algorithms, are studied by using the SVG of the Non-ground neutral three-phase three wire power supply system. The main contents are as follows Firstly, through comparison of two commonly used main circuit topologies, the better performance of the voltage source converter is used as the main circuit of the SVG system, then set the mathematical model; Secondly, through comparing the p-q and ip-iq reactive current detection algorithms which is based on the instantaneous reactive power theory, the ip-iq reactive current detection algorithms are used in the system. In order to reduce errors of the ip-iq detection algorithm caused by inaccurate phase-locked in grid voltage asymmetry,soft phase-locked loop by the combination of two order generalized integrator and positive voltage phase extraction step ring to replace the traditional PLL, effectively improve the accuracy of the current detection algorithm ip-iq Thirdly,based on the mathematical model of SVG in alpha beta coordinate system, a double closed loop control system based on PI controller and quasi PR controller is designed.The performance of the control system is analyzed theoretically, and the tracking effect and control precision of the control system are verified.The working principle of space vector modulation algorithm and implementation steps are presented. Finally, with the help of Simulink simulation software, the simulation model of SVG system is built, and the simulation is carried out under the conditions of inductive load, capacitance load and load mutation. Simulation results show that the SVG dynamic reactive power compensation system has great response speed,tracking performance and compensation accuracy,achieved the design anticipated effect.