三相四桥臂逆变器的三角波辅助控制策略  

Control strategy of three-phase four-leg inverter using an auxiliary triangle waveform

作　　者：马海啸[1] 叶海云[1] 龚春英[2] 

机构地区：[1]南京邮电大学自动化学院,江苏南京210023 [2]南京航空航天大学自动化学院,江苏南京210016

出　　处：《电机与控制学报》2016年第1期14-21,共8页Electric Machines and Control

基　　金：国家自然科学基金(51107057)

摘　　要：针对三相四桥臂逆变器常用的控制方法或者属于开环控制,或者需要大量繁琐的计算,不适用于对动静态性能要求较高的中高频逆变场合这一缺点,提出一种三相四桥臂逆变器的三角波辅助控制策略。该控制策略依据电压电流双闭环控制原理,通过对三相四桥臂逆变电路建立电压电流方程,推导三相输出电压对称所需要的条件,从而发现三角波在各相桥臂的控制中起到至关重要的作用。前三相桥臂在电压电流双闭环控制的基础上在调制信号中注入三角波,使得调制比可以大于1,提高了逆变器的直流电压利用率;第四桥臂则利用构造出的三角波作为调制信号进行PWM控制,确保逆变器在不平衡负载条件下输出电压对称。设计一台6 k VA原理样机,仿真和实验结果证明了该控制策略的可行性。The common control methods of Three-phase four-leg inverter are open loop control or need a lot of tedious calculation. These methods are not fit for medium-high frequency inverters,which require higher dynamic and static performance. In order to overcome these shortcomings,a control strategy of Three-Phase Four-Leg inverter using an auxiliary triangle waveform was proposed. This control strategy was based on voltage-current double closed loop control principle. Through establishing the voltage and current equations of Three-phase four-leg inverter and deriving the conditions of ensuring the symmetry of three-phase output voltages,the important roles of triangle waveform were found to control all the legs. In this strategy,the first three legs adopted voltage-current double closed loop control method with a triangle wave injection. The modulation ratio could be greater than one,so it can improve the utility ratio of DC voltage. The fourth leg adopted Pulse Width Modulation control method using a composed triangle wave as the modulation signal. The control of this leg ensured that three-phase output voltages were symmetrical when the inverter supply unbalanced loads. A 6k VA prototype was designed. The results of simulation and experiment proved the feasibility of this control strategy.

关 键 词：三相四桥臂逆变器 三角波 双闭环控制 对称分量法 零序谐波 

分 类 号：TM464[电气工程—电器]