Abstract
In this paper, the different techniques for the field weakening, also known as constant power speed range (CPSR) operation, for permanent magnet synchronous motor (PMSM) will be introduced and analysed. Field weakening of PMSM, can be done using either vector control (VC) or conventional phase in advance (CPA). Implementation of these techniques depending on some features and constrains. Most of these features and constrains came from the motor parameters. One of these constrains is the motor inductance which determining whether the motor can be driven in the CPSR or not. A new approach for the field weakening will be discussed and to be verified to overcome this constrain. The new approach will be verified through both techniques VC and CPA.