目前死区时间补偿、减少死区时间和无死区控制是关于三相逆变器中死区影响的主要研究方向。在分析了多种死区控制策略局限性的基础上,提出了一种新型基于免疫算法的逆变器无死区优化算法。该方法的创新之处是采用的SVPWM划分扇区和优化无死区控制方案,不需要精确的电流极性检测装置。对新控制策略进行大量仿真研究,仿真结果证明该算法所产生最优SVPWM控制序列与常规控制策略相比不仅无需设置死区时间,还能明显减小逆变器输出波形的总谐波畸变率和提高输出电压基波幅值。
Considerable studies have been discussed to compensate or minimize or eliminate the dead-time effect of three phase inverter. First, this paper analyzes the limitations of the previous strategies. Then, SVPWM sequence calculated by Immune Algorithm (IA) for dead-time elimination and compensation is proposed for the three-phase bridge inverter. The proposed scheme implements the dead-time elimination in most of the reference current fundamental period but switches to the novel dead-time compensation around the zero crossing point. Furthermore, the simulation results are given to verify that the THD of output waveform generated by SVPWM is significantly reduced and the amplitude of output voltage is improved.