This paper deals with characteristics of interior permanent magnet synchronous motor considering anisotropic characteristics of electrical steel sheets. Motor characteristics of back electro-motive force (EMF), d-q axis inductances, and core loss are calculated by FEA considering anisotropy of electrical steel sheets and compared to the results from experiment and general FEA; using single mate...

AIM To examine the effects of low-amplitude, low frequency electromagnetic field therapy (EMF) therapy in patients with persistent chronic lower back pain associated with degenerative disc disease. DESIGN Double-blind, randomized and placebo controlled. INTERVENTION EMF using a medical device resonator; control group underwent same procedures, except the device was turned off. OUTCOME MEA...

Abstract— Brushless motors are gaining attention from various Industrial manufactures because of its high efficiency, noise less operation and high speeds. In conventional control methods of Brushless Dc motors, the back electromotive force is assumed to be in ideal form i.e., Trapezoidal form, so that rectangular currents are injected from the inverter. In real time, the back-Emf may not to be...

A novel speed estimation approach with control system based on model reference adaptive control (MRAC) is presented for low cost brushless dc motor drives with low-resolution hall sensors. The back EMF is usually used to estimate speed. But the estimation result is not accurate enough at low speeds because of the divided voltage of stator resistors and too small back EMF. Moreover, the stator r...

The Permanent Magnet Brushless DC (BLDC) motor offers higher efficiency, low maintenance, reduced weight and compact construction. For many industrial applications, the BLDC motor is increasingly being used. This paper presents a new sensorless drive scheme for BLDC motor based on the back EMF difference. The commutation point of the drive is determined by detecting the Zero Crossing Point (ZCP...

In this paper we give energy-optimal excitation current waveforms for a permanent magnet synchronous motor that result in a desired average torque. Our formulation generalizes previous work by including a general back-EMF waveform, voltage and current limits, an arbitrary phase winding connection, a simple eddy current loss model, and a trade-off between power loss and torque ripple. Determinin...

This paper describes a simple way to control the Brush Less DC Motor (BLDCM) for electrical applications. To control this machine it is generally required to measure the speed and position of rotor by using the sensor because the inverter phases, acting at any time, must be commutated depending on the rotor position. The position sensors make the motor system more complicated and mechanically u...

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 ...