全桥逆变电路偏磁抑制新方法

New magnetic bias suppression method for full bridge inverters

针对全桥逆变电路极易产生偏磁,造成系统可靠性低的难题,提出了一种模拟检测与数字控制相结合的偏磁实时检测与抑制新方法.基于同时采集变压器原边电流和输出电流并参与控制的思想,设计了相应的检测电路,以能够实时输出偏磁信号产生的时刻和强弱.由数字控制器实时调整PWM输出脉冲,保证系统能够快速、有效地抑制偏磁.结果表明,文中所提出的方法具有一致性好、通用性强、稳定性和可靠性高的特点,控制策略灵活多变,可广泛应用于全桥逆变电路拓扑.

To overcome the magnetic bias and low reliability of conventional the full bridge inverter,a magnetic bias real-time detection and suppression method is proposed.The method combines advantages of the analog detection and digital control,in which the transformer primary current and the output current are acquired simultaneously to participate the dynamic control process.The detection system can output the moment and strength of the magnetic bias signal in real time,by which the digital controller can adjust PWM driving pulses and ensure that the system can quickly and effectively suppress magnetic bias.Experimental results show that the proposed method has good consistency,versatility,stability and high reliability,which can be widely used in the system composed of full bridge inverters.