Increasing the saliency ratio of fractional slot concentrated winding interior permanent magnet synchronous motors

Abstract

In permanent magnet synchronous motor (PMSM) servo systems, the saliency ratio is an important factor in sensorless control and flux-weakening control. Compared with the interior PMSM (IPMSM) with distributed windings, the IPMSM with concentrated windings gains more popularity in servo system applications. However, the saliency ratio of current fractional slot concentratedw i n d i n g s(F S C W s)I P M S Mi sl o wa n dh a r dt oi n c r e a s e ,w i t h o u tm u c hl i t e r a t u r e investigating how to improve the ratio. In this paper, the components of d-a n dq-axes inductances of FSCW IPMSM are determined, a novel concept named mechanical phase region is introduced and the key parameters influencing the saliency ratio of FSCW PMSMs have been investigated through thorough theoretical analysis and simulation. The design principles on increasing the saliency ratio of FSCW IPMSMs are proposed and the maximum saliency ratio of a 10 poles 12 slots motor is obtained. On the basis of the theory, a novel rotor structure with higher saliency ratio is designed. A new experimental method of measuring d-a n dq-axes inductances closest h i sp a p e rw i t ht h r e e experimental prototypes built to verify the theory and simulation results.

Analytical Calculation of D- and Q-axis Inductance for Interior Permanent Magnet Motors Based on Winding Function Theory

“…The influence of saturation and nonlinearity is analyzed. In [21], the motor is divided into several mechanical phase regions according to the winding distribution. On the basis of the mechanical phase region and equivalent magnetic circuit, the d-and q-axis inductances are predicted.…”

Node Mapping Criterion for Highly Saturated Interior PMSMs Using Magnetic Reluctance Network

“…The demand for Permanent Magnet Synchronous Machines (PMSM) is rapidly increasing in high-performance applications, such as electric vehicles [1][2][3][4], due to their high power density. In particular, the configuration of buried magnets inside the rotor is becoming very popular, because of the additional torque made available to saliency, their wide constant power speed region, and their high demagnetization withstand capability, among others [5,6].…”

Reduction in distortion of the synchronous generator voltage waveform using a new winding pattern

“…The concentrated windings are used in permanent magnet (PM) machines, but nowadays they are applied to PM machines as fractional slot concentrated winding for high-torque low-speed applications. The effects of the number of slots, poles and phases on distortion, iron and copper losses, noise and vibration are discussed in [1][2][3][4][5][6][7]. Bianchi and Fornasiero [8] presented the index of rotor losses for fractional slot PM machines based on the numbers of slots and poles.…”