Study on Ultimate Output of CSI Applied to Battery Discharg System

Abstract

Theoretically current-source inverter (CSI) can output a inverting current the amplitude of which can be any value provided the duty ratio is small enough. And the output current can remain steady. But in actual operation CSI has its out put limitation both for simulation and test. When the given current is big, the output current will be unsteady. But the above mentioned current can be obtained when CSI is controlled by semi-open-loop which means that a proper reference current is set. It is dangerous because it might cause short circuit between powers of both sides. The output characteristic of current-source inverter (CSI) is studied from the mechanism when SVPWM generate the trigger impulse. The reason that the output between simulation and test vary greatly is discussed. A concussion judgment module is adopted to detect the CSI's output state. The module separated the amplitude information and phase information of the reference current. Regulate CSI's output current amplitude by pay attention to the proportion between reactive component and active component. Simulations and tests proved the correctness and feasibility of the method.