New high power, high performance power converter systems

A new, high performance, low cost power converter system architecture is pr oposed. The system consists of a main converter and a multifunctional load conditioner. The main converter deals with most of the power flow running a t a low switching frequency. The load conditioner is designed at a much low er power level running at a high-switching frequency. The load conditioner can 1) act like a current source and inject harmonic currents required by the l oad; 2) act like an active resistor to provide damping to the main converter; 3) for three-phase inverters, decouple the coupling sources in the main inv erter model in the rotating coordinates to make the control loop design for the main inverter much easier. The concept has been proved by simulation and experimental results on a 150 kW high performance three-phase utility power supply prototype. The propos ed system configuration can be used in high power de-de converters, inverte rs, PFC and UPS applications.