A three-level space vector modulated grid connected inverter with control scheme based on instantaneous power theory

In this paper the control scheme of a three-level three-phase inverter for grid integration of distributed generation (DG) units is investigated. Furthermore, the inverter compensates the reactive power of the load. The presented control scheme is based on instantaneous power theory in order to generate the appropriate inverter reference currents. In the outer DC bus voltage control loop and in the inner current control loop, the fuzzy logic (FL) control and the Proportional-Resonant (PR) control is applied respectively. The switching pattern generation is achieved using Space Vector Pulse Width Modulation technique. The steady state and dynamic response of the proposed electric power system has been evaluated under various operating conditions. Simulation results verify the effectiveness of the proposed control system.

► The proposed system uses p–q theory in combination with SVM without d–q transformation and PLL.
► The PR controller is applied instead of the conventional PI controller.
► The proposed system retains the ability of active power control and uninterrupted reactive power compensation.
► A three-level NPC inverter is used considering a neutral point balancing algorithm.