Flux-weakening Characteristics of Non-sinusoidal Back-EMF PM Machines in Brushless DC and AC Modes

Back EMF Observer Based Sensorless Four Quadrant Operation of Brushless DC Motor

Brushless DC (BLDC) motor drives are becoming more popular in industrial, traction applications. This makes the control of BLDC motor in all the four quadrants very vitalThe motor is operated in four steady state operating modes of torque-speed plane. To control a BLDC machine it is generally required to measure the speed and position of rotor by using the sensor because the inverter phases, ac...

Dynamic Behaviour of an Electronically Commutated (Brushless DC) Motor Drive with Back-emf Sensing

Conventionally, BLDC motors are commutated in six-step pattern with commutation controlled by position sensors. To reduce cost and complexity of the drive system, sensorless drive is preferred. The existing sensorless control scheme with the conventional back EMF sensing based on motor neutral voltage for BLDC has certain drawbacks, which limit its applications. This paper presents the dynamic ...

Dynamic Motor Parameter Identification for High Speed Flux Weakening Operation of Brushless Permanent Magnet Synchronous Machines

An experimental investigation is conducted to determine the behaviour of brushless PM synchronous machine parameters in the high speed flux weakening operating range. Real-time operating characteristics are determined for two commercially available 4 N·m interior PM synchronous machines. Special computer assisted measuring techniques are employed using an experimental vector controlled drive, c...

Improved Speed Estimation in Sensorless PM Brushless AC Drives

The application of flux-observer-based sensorless control to permanent-magnet brushless ac motor drives is described. Current methods of speed estimation are assessed, both theoretically and experimentally, and an improved method, which combines the best features of methods in which speed is derived from the differential of rotor position and from the ratio of the electromotive force to excitat...

Optimal Design of Ultra-High Speed Axial Flux Permanent Magnet Motor with Sinusoidal Back-EMF