Power Optimization Analysis And Active Disturbance Rejection Control Research Of Wave Power System

Wave power is a clean,pollution-free and continuous renewable energy,which has a wide distribution area,large reserves,high energy density as well as long available time.It is an important form of new energy power generation in the future.Reasonable development of wave power can help solve the power dilemma of coastal cities and islands.However,wave motion has the characteristics of disorder,time-varying and randomness,which makes traditional control methods are susceptible to wave excitation and harsh environments,resulting in low energy acquisition efficiency,poor stability,and unfavorable commercialization.This paper takes the direct-drive wave power system as the research object,and proposes wave frequency estimation schemes and an active disturbance rejection strategy for the wave power system.According to Newton's laws of mechanics and the principle of equivalent circuit,the frequency response function of the wave system under resonance conditions is deduced,and the optimal load formula of the system is obtained.The mathematical model of the permanent magnet linear motor after coordinate transformation is used to obtain the control expectation based on the maximum wave capture.The maximum power control parameter of the wave power system is related to the wave motion frequency,which has the feature of low frequency and small amplitude.The windowed Fourier decomposition method is used to analyze the distribution of the wave spectrum and extract the main frequency.In order to achieve high-precision online tracking of time-varying excitation frequency,a generalized integral frequency-locked loop and an adaptive Kalman wave frequency estimation scheme are used to monitor the frequency changes of random wave.The simulation shows that the three schemes can obtain the main frequency band of random wave excitation,and the calculation speed is fast.Aiming at tracking the best electromagnetic force of the wave system under the action of noisy chaotic waves,the current active disturbance rejection control strategy is proposed to filter out the high-frequency noise components in the wave input,extract the effective differential signal,predict and compensate the disturbance,improve the desired signal tracking effect.By this way,both the wave energy capture rate and system power output are increased.Combining the characteristics of the grid-connected and island operation of the wave system,an active disturbance rejection control scheme for the grid-side inverter is designed to reduce the sensitivity of the system to disturbances and improve the overall stability.A wave power system simulation model based MATLAB/SIMULINK is built to verify the effect of the control strategy.The space vector modulation current control is using for machine side.The simulation shows that compared with the traditional control scheme,the proposed ADRC strategy is capable of helping machine side current track the expected value dynamically under the random waves.And the error value is small,the chattering phenomenon is obviously suppressed,as well as the system output power is increased.The grid-side system based on auto-disturbance rejection control can meet the current phase and frequency requirements when connecting to the grid.And the proposed scheme can ensure the anti-interference ability and the reliability of power supply on the load side during island operation.