三相电源整流器系统故障诊断仿真研究

Fault and State Estimation of PWM Rectifier Based on Sliding Mode Observer

针对三相PWM整流器系统状态不易跟踪估计和故障重构问题,为保证供电系统的安全,提出了采用滑模观测器控制技术的诊断方法。首先,利用整流器开关函数和占空比两种数学模型描述方法,并基于三相电压型PWM整流器拓扑结构和工作原理,建立了PWM整流器的交流数学模型;其次,采用滑模控制技术和等价输出注入方法,通过构造滑模观测器,实现了对系统状态跟踪和估计的目的。之后,在状态估计的基础上,给出了一种故障重构的方法,实现了系统故障重构的目的;最终,通过实例仿真,验证了使用滑模观测器能够快速跟踪整流器系统状态,准确诊断系统故障信号,为保证供电系统安全提供了科学依据。

Aiming at the problems of PWM rectifier＇ s state estimation and fault reconstruction,the diagnostic method that based on sliding mode observers is proposed.Firstly,based on the research of the topology and working principle of three-phase voltage source PWM rectifier,the switching function and duty ratio are used to establish the PWM rectifier＇ s mathematical model.Secondly,according to the concept of equivalent output injection and sliding-mode control technique,a sliding mode observers is constructed to estimate the states of PWM rectifier dynamics.Based on the state estimation,a kind of state reconstruction method is proposed,the purpose of reconstruction of system failure can be achieved.Finally,the simulation is given to verify that through using sliding mode observers rectifier＇ s state can be tracked rapidly and system＇s fault signal can be reconstructed accurately.