A Model for Power Planning Considering Large Offshore Wind Power Integration and Rotational Inertia Constraints

To cope with the significant challenge to the power source planning and operation stability of the receiving-end system in southeast coastal provinces and cities in China due to the constantly increasing proportion of uncontrollable power such as extrinsic DC power and offshore wind power, a power planning model considering grid-connection of offshore wind power and its rotational inertia constraints was proposed. Firstly, considering the seasonal characteristics of historical output data of offshore wind power, the uncertainty of offshore wind power was described by scenario analysis method. Secondly, taking the lowest annual comprehensive cost as objective, a bi-layer power planning model, in which the planning was optimized by the outer-layer and the operation was optimized by the inner-layer, was constructed. Thirdly, the quantitative relation between rotary inertia level and frequency response index was analyzed, by means of applying the constraint of rate of change of frequency (abbr. RoCoF) in the inner-layer model the adequate inertial support capacity of the planned structure of power source was ensured. By use of genetic algorithm and Cplex solver the bi-layer planning model was solved. Finally, the feasibility and the effectiveness of the proposed model are verified by the simulation results of computing example, meanwhile, the impacts of the offshore wind power permeability and proportion of extrinsic DC power on power planning results were analyzed and induced.