Motor And Shafting Design In Flywheel Energy Storage System

The flywheel energy storage system (FESS) with its high efficiency, high energy storage density, high modularity advantage, has a broad development prospects. The flywheel energy storage system, the design of energy conversion, high speed motor and the energy storage carrier, flywheel are vitally related to energy storage performance. Based on the electromagnetic and mechanical strength performance of high-speed motor and the design of flywheel shafting. The initial design which can fulfill the requirement of FESS is obtained.In this paper, permanent magnet synchronous motor is chosen as the flywheel energy storage high-speed motor. The general high-speed motor design process is used to determine the various parameters for the motor and a design scheme, is achieved. Ansoft RMxprt is used for rapid modeling and calculation using magnetic circuit method to get the basic electromagnetic performance of the machine. Then, a MAXWELL 2D model is builted accordingly, simulations are carried out.The motor plan is selected as the final motor design for its good electromagnetic performance.Protection of permanent magnet has been one of the major concerns of mechanical strength in the high speed motor. This paper analyzes the permanent magnet strength influenced with the interference amount and chooses the appropriate amount of interference; The relationship between the sheath thickness and the strength of the sheath is revealed and the suitable thickness of sheath is selected. Finite element calculation is carried out to prove the validity of the calculation results of analytical method.From four aspects of the flywheel energy storage energy storage, the flywheel shafting material strength caused by rotation, the flywheel shafting strength caused by the unbalanced eccentricity and the limitation on the working speed by natural frequency of the flywheel shafting, size parameters of the flywheel energy storage shafting is studied and the relationship with the above four factors is revealed. Finally aiming at lightweight, these four factors as constraint conditions, size optimization design and analysis is carried on for the parameters of the flywheel shafting. A set of lightweight flywheel shafting size parameters is obtained to meet the design requirements of the system.