Research On The Converter For A Flywheel Energy Storage Power Generation System

Energy is the driving force for the development of modem society.An important way to realize the efficient use of energy is to energy storing.Flywheel energy storage is a kind of new energy storing technology.Because of its advantages of high specific energy,high specific power,non-pollution,nosieless and long life,flywheel energy storage has been developed rapidly.At present,flywheel energy storage technology has been successfully applied in the UPS,power systems,hybrid locomotives,etc.The thesis,which is mainly focused on the power generation part of flywheel energy storage system,are arranged as following:Firstly,this thesis introduces the basic structure and working principle of a flywheel energy storage power generation system.In the power generation,the DC bus voltage decreases with the motor speed decreasing.In this thesis,the principle of Boost converter is used to make the motor windings turn on.Power generation control strategy for MATLAB simulation.In addition,through further research on control strategy of the flywheel energy storage power generation,three-phase conduction control strategy is proposed on the basis of two-phase conduction power generation,and the feasibility of three-phase conduction is verified via MATLAB simulation.The results show that the control strategy of three-phase is better than the two-phase conduction control strategy in maintaining the bus voltage constant and discharging depth and step-up ratio.Secondly,in order to design the bi-directional converter of the flywheel power system better,the parallel connection of the MOSFET is studied.The modeling and simulation of the MOSFETs by Saber software is carried out.The effects of parasitic inductance,parasitic resistance and parasitic capacitance on the MOSFET shunt are analyzed.The causes of the unequal flow are analyzed and the method to improve the current sharing is also carried out.Finally,the hardware circuit of the control system based on TMS320F28335 is designed,including the design of the minimum system control board of the four-layer DSP5 the design of the expansion board including the AD sampling circuit.On the basis of the hardware,the program of software is designed though CCS development platform.The core circuit of the flywheel energy storage system is experimented.