摘要
为提高采用阶梯波调制法的链式静止同步补偿器(STATCOM)输出电压和输出电流的波形质量,提出一种直流侧电容电压平衡控制策略。分析导通方式、工作模式和电容电压变化量的关系,总结出链节的四种工作区间(A、B、C、D)及各个区间导通角与电压变化量的数值关系。根据单个采样点电容电压的排序结果在各个区间选择导通方式,使电压越高的链节在A和D区间电压上升程度越小,在B和C区间电压下降程度越大,从而将电容电压向平均值调整,在调整过程中不改变各个链节的导通角、调制比等参数。为避免锁相环误差引起的工作模式判断不准确问题,根据两个相邻采样点电容电压大小和变化量判断装置的工作模式(容性、感性)。三相11电平链式STATCOM的实验结果验证了控制策略的可行性和有效性。
A DC capacitor voltage balance control strategy is proposed, in order to improve waveform quality of the output voltage and output current of cascade STATCOM based on step wave modulation method. This paper analyzed the relation of conduction mode, operating mode and capacitor voltage variation, summarized the four kind of operating regions（A, B, C, D） and numerical relationship between conduction angle and voltage variation in every region. The conduction mode in every region according to capacitor voltage sequencing result in every sampling point is ＇selected, which makes the higher chain Voltage, the smaller the voltage rise degree of A and D regions, and makes the higher chain voltage, the bigger the voltage decline degree of B and C regions, so that regulates capacitor voltage toward mean value. The parameters of link conduction angle and modulation ratio do not change in adjustment process. The value and variation of capacitor voltage on two adjacent sampling point are used to judge the operating mode （capacitive, inductive） in order to avoid operating mode judgment inaccuracy that be caused by PLL error. The experimental results verify the feasibility and effectiveness of the proposed control strategy on experimental platform of three-phase eleven-level cascade STATCOM.
出处
《电工技术学报》
EI
CSCD
北大核心
2013年第10期280-287,共8页
Transactions of China Electrotechnical Society
基金
陕西省重点学科建设专项资金资助项目(105-00X901)
