Distributed Optimization Method for Active Power of Virtual Synchronous Doubly-fed Wind Farm Considering Main Shaft Fatigue Load

To reduce the main shaft fatigue load borne by each doubly-fed wind turbine based on a virtual synchronous generator control strategy in the wind farm when responding to changes in grid power demand values, a distributed optimization method for active power considering main shaft fatigue load based on an improved penalty coefficient alternating direction multiplier method is proposed. Based on the derivation of a discretized model that quantifies the relationship between the active power demand value of a unit and its main shaft torque, the objective function is to minimize the total fluctuation of the main shaft torque for each unit and constraint conditions are set according to the operating status of the unit. To share the computational pressure of the central controller of the wind farm, the objective function is disassembled into a distributed optimization structure with a main function (central controller) and multiple sub-functions (local controllers) based on the alternating direction multiplier method with improved penalty coefficient, and the local controllers optimize the value of the active power demand of each unit online to achieve the reduction of the main shaft fatigue load. The simulation results verify the superiority of the proposed optimization method. © 2024 Power System Technology Press. All rights reserved.