Design and Control of Utility Grid Interfaced Wind Energy Conversion System for Bipolar DC Micro Grid

This paper proposes the design and control of power flow in a utility grid interfaced wind energy conversion system for bipolar DC micro grid. The proposed system consists of two power conversion stages, such as wind energy conversion (WEC) systems connected at each pole of bipolar DC micro grid with simple boost converters and in the second stage a three level neutral point clamped (NPC) inverter to interface with the utility grid. A look-up table based maximum power point tracking (MPPT) is used to extract the maximum power from each wind energy conversion system and a voltage oriented proportional resonant (PR) controller for the control of three level NPC inverter. Performance of the proposed system is validated in detail by simulations to achieve bipolar DC bus voltage regulation and DC link capacitor voltage balance for changes in wind velocity, variation in loads on bipolar DC micro grid, and also at point of common connection (PCC).