摘要
分析了中点钳位型三电平变换器的中点电压数学模型,推导出三相功率与零序电压的传递函数。提出一种新型的注入零序电压控制方案,该方案通过控制中点处的零序总功率为0,来实现中点电压的平衡控制。具体方案是,通过计算中点处的三相功率偏差,经PI调节器输出零序电压调制波,经过3 s/2 r坐标变换,叠加至三相基波调制波,并采用SVPWM调制算法实现。仿真显示,方案能够实现中点电压的平衡控制,具有较好的动态响应。
In this paper, the mathematical model of the neutral point clamp three-level converter is analyzed and the transfer function of the three-phase power and zero-sequence voltage is derived. And a novelty zero-sequence voltage injection strategy for the neutral point voltage balance is proposed. The strategy uses three-phase power to calculate the zero-sequence voltage component. The zero-sequence voltage modulation wave component output from the PI regulator, undergoes the coor-dinate transformation through 3 s/2 r and then is added to the fundamental modulation wave. The Matlab simulation shows that the control strategy has a better dynamic response.
出处
《电网与清洁能源》
北大核心
2015年第2期98-103,共6页
Power System and Clean Energy
关键词
三电平变换器
中点钳位型
中点电压平衡
零序电压
three-level converter
neutral point clamp
neutral point voltage balance
zero sequence voltage
