A Hybrid Overload Current Limiting and Short Circuit Protection Scheme For Voltage Mode Inverters

Abstract

In this paper, a combined current limiting algorithm is proposed for voltage mode – controlled inverters. The proposed method combines the analog and digital current limiting techniques. It provides fast response and better voltage waveform quality even during the transient stages. The proposed method is implemented and tested with a three-phase 10kVA voltage mode – controlled inverter. In addition, the digital and analog current limiting techniques are also employed separately and tested at the same conditions. Obtained results are compared with the proposed combined current limiting method. It is seen that proposed hybrid technique provides successful current limiting performance with its fast response in short circuit and overcurrent conditions, and significantly improves the reliability and fault tolerance of the inverter. Besides, the proposed current limiting algorithm adds fault clearing capability to the inverter.