一种具有容错功能的多桥臂开关功放电路

A Multi-leg Switch Power Amplifier Circuit With Fault-tolerance Function

功率放大器是主动磁悬浮轴承系统中主要的执行元件,但由于开关管长期工作在高频状态下,易发生故障,因此十分有必要开展故障容错研究。首先,提出一种具有容错功能的多桥臂开关功放拓扑结构,能同时实现对五相六桥臂开关功放的开路和短路故障容错控制。其次,分析所提拓扑的工作原理,并提出以电流斜率变化作为故障判断条件的方法,采用相应的容错控制策略,实现冗余桥臂对故障桥臂的替换,以达到容错的目的。最后,通过仿真和实验验证了该拓扑在故障后经过容错能使负载电流恢复正常,证明了拓扑的合理性和可行性。

The power amplifier is an important part of active magnetic bearing systems;however,the switch is prone to malfunction when operating at high frequencies for a long time.Therefore,it is necessary to conduct fault tolerance research.This paper proposes a new topology with fault-tolerant function for a multi-leg switching power amplifier,which can simultaneously achieve fault-tolerant control of open-circuit and short-circuit faults for a five-phase six-leg switching power amplifier.This paper analyzes the working principle of topology and proposes a method of using current slope change as the fault judgment condition.Corresponding fault-tolerant control strategies are adopted to achieve the replacement of a redundant leg with a faulty leg,achieving the goal of fault tolerance.Finally,simulation and experiments have verified that the topology can restore the load current to normal after fault tolerance,proving the rationality and feasibility of the topology.