Maximum Wave Energy Capture Analysis And Power Optimization Control Of Wave Power Generation System

Wave energy is renewable and contains abundant energy,so wave power generation has gradually attracted attention.However,wave energy has problems such as randomness and volatility,which result in low energy conversion efficiency of wave power generation systems and can not operate stably for a long time,which restricts its application development and commercial development.Aiming at the problems of low capture rate of current wave power generation and large fluctuations in system output power,this paper takes the direct-drive permanent magnet linear synchronous generator wave power system as the research object to study the system power optimization control.It achieves the effect of improving the energy capture efficiency of wave power generation and the stable operation of the system.Firstly,to analyze the operation of wave power system in the sea,the wave force on the float is ana lyzed based on the F-K assumption method and the mathematical model of the permanent magnet linear synchronous generator are established.According to the maximum power point tracking control principle,the maximum wave energy capture condition of the wave energy power conversion device is obtained,the output power characteristic curve of the system is deduced,and analyze the maximum wave energy capture control strategy for wave power generation systems.Secondly,due to the simple structure of the crisscross optimization algorithm,it is conducive to solving the optimization problem of nonlinear systems.In order to improve the wave energy capture efficiency of the wave power system,based on this algorithm,a power optimization control scheme for the wave power system is proposed.The optimal motor magnetic force and q-axis stator reference current are obtained through the self-optimization function of the horizontal and vertical crossover operator of the algorithm,and the space vector control is applied to realize the system power optimization.The simulation shows that the proposed control method can effectively improve the energy capture rate of the system under water conditions where the frequency is stable and close to the natural frequency of the float.Then,aiming at the irregularity of the waves in the actual sea area,in order to reduce the dependence of the algorithm on the system parameters,a double disturbance observation algorithm is proposed to realize the system MPPT control.Two switched capacitors are used to control the duty cycle to adjust the system voltage,optimize the electromagnetic force of the motor,and then adjust the active power output of the power generation system.The double disturbance observation algorithm expands the voltage adjustment range,reduces the dead zone and misjudgment of the algorithm,and enhances the anti-interference ability.The simulation shows that the proposed control method enhances the maximum power point tracking effect of the wave power generation system when the wave input and load change suddenly.Finally,the fluctuation of the output power of wave power generation will cause the fluctuation of the bus voltage.For this reason,a power fluctuation suppression strategy based on hybrid energy storage is proposed.We build a DC microgrid for island wave power generation,and use low-pass filter control in hybrid energy storage to achieve unbalanced power distribution.The improved DC bus voltage signal control is used to control the charging and discharging of the hybrid energy storage to balance the power in the system and maintain the stability of the bus voltage.The simulation model is built in the SIMULINK environment,and the RT-LAB real-time simulation platform test verifies the effectiveness of the proposed control method under complex working conditions.