Study On Energy Storage On Solar Flywheel System

With the continuous progress of human society and rapid development of technology,the problems such as the conflict between demanding and supplying of energy,the polluted environment caused by over used fossil fuels need to be solved immediately.Nowadays,many countries are developing the clean and sustainable energy;because of the advantages of inexhaustible energy and widespread distribution,relatively simple structure,no pollution,long life,etc.,using the solar power to produce electricity has been a heated one.But how to store the electricity from the solar energy has become a problem on restricting the wide usage of the solar energy.Flywheel energy storage is a new mechanical energy storage mode,and the flywheel blades are driven by a motor by which the input electrical energy is transformed into mechanical energy and stored in the high speed flywheel blades.For its advantages of high conversion efficiency,less pollution and long life,the flywheel energy storage has a broad developing space.Due to the good speed performance,most existing prime motors in flywheel energy storage system use the synchronous motor,but its structure is complex production needs higher price,while the induction motor has simple structure,convenient maintenance good price,so nowadays more and more speed control systems use the induction motor.First,in this paper,the principle of photovoltaic cells is analyzed,and a mathematical model that provides power to the entire system is established,through the analysis,photovoltaic cells to provide power is limited and susceptible to the external environment(such as temperature,sunlight intensity).Second,asynchronous motor is used as the prime mover to drive the flywheel in the flywheel energy storage system,and converts electrical energy into mechanical energy which is stored in the flywheel.Using the indirect field orientation method as a kind of the vector control for controlling induction motor,and power tracking model was built based on slip frequency method and the limited input power,constantly sampling power revised by the photovoltaic cells and then through the model to calculate the need of control parameters,combined with the slip frequency method for controlling motor power.The method can be constantly revised according to the change of the input power control parameter,to achieve the purpose of the dynamic control of the motor,so as to achieve the power of the track.Finally,this thesis combines the photovoltaic cell module,the slip frequency module,power inverter and tracking model and transformers as a whole part and analyzes it systematically,establishes a systematic control block diagram,and under the Matlab/Simulink circumstance proceeds the modeling and simulation.Through analyzing and summarizing,the results of simulation show that the system has the advantages of fast responding speed,high tracking precision,good control performance and good practicability.