基于高频隔离交交直接变换器的新型STATCOM研究
Research of Novel STATCOM Based on Insolated High Frequency AC-AC Converter
-
摘要: 本文首先介绍了一种基于交交直接变换器的新型无功补偿器,没有直流储能环节,补偿器可靠性更好,成本更低。以推挽正激式交流变换器为研究对象,分析了新型STATCOM的工作原理、补偿特性以及控制策略。首次将高频隔离变换器引入新型STATCOM的研究,实现了网侧和补偿电容的电气隔离,增大了补偿器补偿容量。提出了一种基于单相无功电流检测方法的直接电流控制方案,相较于目前基于正交分解模块和dq坐标变换的控制方式,该方案计算量小,结构简单,容易实现。最后,进行了仿真实验,验证以上理论分析以及本文提出的直接电流控制方案。仿真结果表明,基于推挽正激式交流变换器的新型STATCOM可以实现对网侧无功电流的实时动态补偿,系统稳定性好,闭环控制调节快速,无静态误差。Abstract: Firstly, a novel STATCOM based on AC-AC converter is introduced in this paper, which lack of DC link energy storage and is more reliable and cost-effective. Push-pull forward AC converter is used for the study, and the working principle, compensation characteristics, control strategy is studied. Insolated high frequency ac-ac converter is introduced intonovel STATCOM, as a result, electrical isolationbetween grid-side and the compensation capacitor is implemented and compensation capacity is increased. Direct current control scheme which based on single-phase reactive current detection methods have been proposed in this paper. Compared with present control mode which based on orthogonal decomposition module and dqcoordinate transformation, the scheme proposed has less calculation amount and simple structure, and it is easy to achieve. Finally, the simulation was carry out to verify above theoretical analysis and the proposed direct current control scheme. The simulation results show thatnovel STATCOM based on insolated high frequency AC-AC convertercan compensate reactive current real time and dynamically. The system is stablewell, closed-loop can adjust the compensator quickly without static error.