摘要
级联多电平STATCOM在大功率场合具有很好的应用前景,但各串联模块的直流侧电压容易出现不平衡的现象,严重影响了STATCOM的补偿效果。因此,维持各模块直流侧电压均衡与稳定成为级联多电平STATCOM技术应用的关键。文章首先简要介绍了级联多电平STATCOM的基本结构、无功补偿原理和控制算法,在此基础上,结合已有的硬件控制方法与软件控制方法的优点,提出一种附加飞渡电容均衡各模块直流侧电压的方法,相对于传统硬件控制方法,减少了器件开销;相对于传统软件控制方法,降低了控制难度。最后,以级联两模块五电平STATCOM为例进行了仿真,结果表明,文章提出的方法可以实现各模块直流侧电压稳定、均衡。
Cascaded multilevel converter-based STATCOM is widely used in the high-power situations,but the DC-side voltage of modules in series is hard to balance,which seriously affects the compensation effect of the STATCOM.Therefore,it is very important for the technology application to maintain balance and stability of DC-side voltage of each module.In this paper,we first describes the basic structure of STATCOM,reactive power compensation principle and control algorithms briefly.Then,drawing lessons from the existing hardware and software control method for reference,we propose a new method to control the DC voltage by using an additional flying-capacitor.Compared with the traditional hardware control method,we use fewer devices.Compared with the traditional software control method,our control is less complex.At last,we use cascaded two modules five-level STATCOM as an example for simulation.The results show that the method we proposed can accomplish the DC voltage balance and stability.
出处
《大功率变流技术》
2011年第4期26-31,共6页
HIGH POWER CONVERTER TECHNOLOGY
