Abstract
Due to poor heat dissipation of rotor, especially in flywheel energy storage system (FESS) for uninterruptible power supply (UPS), there is a higher risk of irreversible demagnetization by rotor temperature rising. Irreversible demagnetization of permanent magnets by rotor loss always is a critical problem of high-speed permanent magnet synchronous machine (PMSM). The stabilization and efficiency can be increased by reduction of rotor loss. By Finite Element Method simulations with experiment date, the rotor temperature rising of the prototype PMSM mainly comes from rotor loss induced by time harmonic. The distribution and components of prototype rotor loss are given. Rotor loss is analyzed by equivalent magnetic circuit with considering time harmonic magnetomotive force in this paper. According to analysis of rotor loss, this paper presents a method to reduce rotor loss without changing stator structure and winding current. This rotor structure optimization will not affect output performance of PMSM. The method has been proved to be available by the no-load experiment finally. It can greatly reduce the rotor loss in no-load operation when PMSM is driven in high-speed operation zone.
Highlights
In the last decades, the permanent magnet synchronous machine systems are widely concerned due to high performances in power density, torque density, and fast respond etc. [1]–[3]
The ability of bi-directional power flow between the mechanical energy and electric energy is another essential feature of permanent magnet synchronous machine (PMSM) systems
In order to achieve higher power density, PMSM systems are optimized for higher speed operation and down-sized [3]–[5]
Summary
The permanent magnet synchronous machine systems are widely concerned due to high performances in power density, torque density, and fast respond etc. [1]–[3]. Rotor loss is caused by magnetic harmonic in PMSM. Wang et al.: Equivalent Magnetic Circuit Reluctance Optimization for Rotor Loss Reduction three parts: Digital Controller, Three-Phase PWM convertor, and PMSM Their unideal design and operation could cause MMF harmonic. This paper gives the method to optimize the rated-speed standby operation of PMSM without changing the working operation condition This rotor structure optimization is much more simple than other ways. The rotor loss of prototype PMSM is obviously caused by harmonic of stator current. From this analysis with inputting the current of PMSM experiment, the main reason of rotor loss is the time harmonic in winding current. A. 1-D MODEL (Equivalent MAGNETIC Circuit) OF PMSM There is no loss in rotor when PMSM is driven under the ideal stator MMF. Khmax,m is one of dynamic maximum boundary of kh. khmax,c is cost maximum boundary of kh
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
