Decoupling Control of the Non-Grid-Connected Wind Power System with the Droop Strategy Based on a DC Micro-Grid

Non-grid-connected wind power theory, which is defined as the optimized integration of grid-connected and stand-alone wind power generation forms, avoids the technical issue of integrating wind power into utility, and creates a new solution for wind power generation. In this paper, the droop control strategy, namely current feed forward control strategy, is adopted for a dc grid based multi-terminal non-grid-connected wind power system which consists of several wind turbines, high-energy-consuming (HEC) loads, energy storage devices, and a grid-connected port. The power decoupling control of different terminals is achieved with the introduced control strategy, and the voltage fluctuation of the dc bus is limited to a small range. What's more, with the proper configuration of the current feed forward the coefficient, not only the normal operation requirement of terminal loads is guaranteed, but also the power exchange between the wind power system and the utility is minimized. Finally, a simulation model is established in the Matlab environment, and the simulation results verify the feasibility of the introduced control strategy. Keep in mind that the strategy could be extended to other hybrid generation systems which consist of several different renewable resources, such as solar power, fuel cell etc.