Space-vector modulated PWM converters for photo-voltaic interface applications: analysis, power management and control issues

This paper presents new power management and control concepts for power converters that interface a photovoltaic (PV) system to an electric utility power system. The interface circuit is a space-vector modulated (SVM), high-frequency, 3φ, PWM buck-type inverter. Decoupled control of DC voltage for peak power tracking, and the quadrature component of AC output current for reactive power flow control is achieved. The inner current loop maintains a preset flow of reactive power from the power converter to the local load and the utility power system. The peak power tracking loop sets the reference value of the outer voltage loop. Small-signal model of the switching power converter, derived in rotating d-q coordinates is used to design the control loops