A novel control strategy for input-parallel-output-series inverter system

This paper presents the topology structure and control method for input-parallel-output-series (IPOS) inverter system which is suitable for high input current, high output voltage and high power applications. In order to ensure the normal operation of IPOS inverter system, the control method should achieve input current sharing (ICS) and output voltage sharing (OVS) among constituent modules. Through the analysis in this paper, input current sharing is automatically achieved as long as output voltage sharing is controlled. IPOS inverter system is controlled by three-loop control which is composed of outer common output voltage loop, inner current loops and voltage sharing loops. Simulation results show that this control strategy can achieve low total harmonic distortion (THD) in the system output voltage, fast dynamic response and good output voltage sharing performance.