Power Allocation And Frequency Offset Control Strategy For Microgrids In Island Mode

In recent years,with the rapid development of the economy,the problem of the energy crisis and the environmental pollution is continually emphasized,and the renewable energy is highly regarded as a main distributed type power source,and the stability problem of the micro grid operation is also a focus of the research.In micro grid power distribution control,droop control is favored due to its unique advantages.However,when microgrids operate in island mode,problems such as frequency offset and unbalanced reactive power distribution often occur.Based on this,an i mproved control strategy is proposed.The full text is as follows:First,a correlation model of inverter,LC filter and voltage and current double closed-loop control was constructed,and filter parameters were selected simultaneously.The traditional dro op control is derived from the relationship between the carrier power and the transmission line impedance in multi inverter parallel.The effect of the line impedance on the power distribution and the ring flow characteristics in the droop control is discu ssed.Then,the relationship between reactive power sharing and inductance was analyzed,and the improved droop control of conventional virtual inductance was introduced.The standard particle swarm fuzzy PID control adaptive virtual inductance strategy is proposed to suppress the circulation,which reduces the power overshoot,improves the control accuracy,and makes the inductance values continuously change in the opposite direction until they are equal.At the same time,the reactive power is evenly dist ributed while restraining the circulation.And a detailed analysis was conducted on the frequency offset issue,and the effectiveness of the proposed control strategy was verified through MATLAB/Simulink simulation.Finally,based on the multi-agent consensus algorithm,a distributed reactive power sharing control strategy and a distributed frequency recovery control strategy were proposed.Each distributed power source utilizes communication technology to obtain reactive power and active power information from adjacent power sources,thereby calculating relative errors.Consistency algorithms and proportional integrators are used for adaptive adjustment to achieve balanced power distribution while reducing frequency deviation.The feasibility of the control strategy is demonstrated through simulation.