摘要
基于H桥级联多电平SVG是目前中压领域有效补偿无功电流的最佳方案之一,而如何保持其直流侧电压平衡的问题却成为其应用在中压场合的一个难点。为此,建立了中压级联SVG的数学模型和详细推导了它的波动过程,并提出了一种分层控制电压均衡的新方法。上层控制主要是在改进的瞬时无功检测算法基础上,根据自适应PI参数实时地调节有功电流指令,进而保持全局稳压和相间均压;下层均压控制则在上层控制基础上补偿一个基于单位化电流的调制波微调量,从而实现每相各单元电压均衡。最后仿真和实验结果表明,该控制方法可有效地应用于中压SVG领域。
The multilevel cascaded H-bridge SVG is one of the best solutions for compensating reactive current in the medium voltage field,and the balance of DC side voltage has become a difficult problem for its application.Therefore,the mathematical model of cascaded SVG in medium voltage is established and its fluctuation process is analyzed in detail,and an improved hierarchical control method based on DC side voltage is proposed.Based on the improved instantaneous reactive detection,the upper control can adjust the reactive reference current according to the adaptive PI parameters in real time,which is used to maintain the total voltage stabilize and three-phases voltage balance;as for the lower voltage control,a modulation signal component based on the unitized current is compensated to the main modulated wave,which can achieve the voltage balance for every unit in any phase.Finally,the method is verified by simulation and experiment for the application of the SVG to a medium voltage level.
作者
彭咏龙
黄江浩
李亚斌
杜鹏
贺宁
PENG Yonglong;HUANG Jianghao;LI Yabin;DU Peng;HE Ning(School of Electrical and Electronic Engineering,North China Electric Power University,Baoding 071003,China)
出处
《电力科学与工程》
2018年第6期1-8,共8页
Electric Power Science and Engineering
关键词
中压级联SVG
直流侧电压均衡
自适应PI
调制波重构
单位化电流
the medium voltage cascaded SVG
DC side voltage balance control
adaptive PI control
modulated wave reconstruction
unitized current
