基于改进Buck-Boost斩波电路的无功补偿器设计

针对电网中大量感性负载的投入使用造成电压降低和畸变的问题,以及现有无功补偿装置存在的不足,提出了一种新型的交流斩波无功补偿器.以改进后的Buck-boost交流斩波无功补偿器为研究对象,分析了交流斩波无功补偿的工作原理、补偿特性以及拓扑结构,通过状态空间方程建立了Buck-boost电路在不同工作状态下的数学模型,推导出补偿电流与占空比之间的关系.在此基础上,利用瞬时无功功率理论检测办法以及直接电流控制策略,搭建了Matlab仿真模型以进行实验验证.研究结果表明,基于直接电流控制的改进Buck-boost交流斩波无功补偿器可以实现对电网侧无功功率进行实时、动态补偿,具有潜在的实用价值.

Design for reactive power compensator based on improved Buck-Boost AC/AC chopper

Aiming at the problem of voltage reduction and voltage distortion due to the extensive use of inductive loads,and some shortcomings of existing reactive power compensation devices,a new AC-AC chopper based var compensator was proposed.The basic principles,compensation characteristics and topology of the improved Buck-Boost AC-AC chopper based var compensator were described,the mathematical model of improved Buck-Boost based on state-space equation was established,the relationship between duty ratio and compensation current was derived.The instantaneous reactive power theory and direct current control method were adopted to build a Matlab model.The results indicate that the real-time compensation of reactive power in grid side can be realized by this var compensator based on a direct controlled Buck-Boost AC-AC chopper,it has potentiouy pratical value.