Fuzzy Logic Control Scheme of Voltage Source Converter in a Grid Connected Solar Photovoltaic System

This paper focuses on control strategy of a voltage source converter based on fuzzy logic controller. A PV array is connected to alternative current (AC) grid via a boost converter and a three-phase three-level voltage source converter. The three phase VSC converts the DC link voltage to AC and keeps unity power factor. The VSC control system uses two controllers. The first one is an external fuzzy controller which regulates the DC link voltage to its reference value and the second fuzzy controller regulates active and reactive grid current components. The active current reference is the output of the DC voltage external controller. The reactive current reference is set to zero in order to maintain unity power factor. Vd and Vq voltage outputs of the current controller are converted to three modulating signals used by the PWM Generator. Result from the simulation shows that the fuzzy controller is capable to stabilize the DC link voltage, the active and the reactive components of the current VSC in the vicinity of references values in various temperature and irradiation condition.