Induction motor speed sensorless torque control, which allows operation at low and zero speed, optimizing both torque response and efficiency, is proposed. The control is quite different than the conventional field-oriented or direct torque control. The produced torque is explicitly continuous output variable of control. A new stator and rotor flux controller/observer based on continuous slidin...

The variation of the directional reflectance of a vegetative canopy with azimuthal view angle becomes prominent when the canopy is illuminated by the sun at large angles from zenith. An extension of a previous directional reflectance model of vegetative canopies is presented to quantify this effect. The results indicate that the cause of the azimuthal variation can be traced to solar flux illum...

Electrical steels are undoubtedly the most important soft magnetic materials in use today. Applications vary in quantities from the few ounces used in small relays or pulse transformers to tons used in generators, motors, and transformers. There are two principal types of electrical steels: grain oriented and non-oriented steels. The grain oriented (GO) electrotechnical steel sheets are widely ...

This thesis discusses various aspects of controlling a permanent magnet synchronous machine with a non-sinusoidal rotor flux density distribution. The transient model of the machine in the rotor oriented dq-frame is derived, including the non-sinusoidal effects. The design of current and speed controllers is also discussed. The current controller is implemented in a permanent magnet machine, in...

This paper deals with implementation of the field-oriented control strategy in an induction machine. The rotor flux orientation strategy tends to give true decoupling control, where the control reference frame rotates at synchronous speed and is held by the rotor flux. Simulation results show that the machine presents a high dynamic performance similar to those of DC machines. This approach pre...

We report detection of strong infrared thermal emission from the nearby (d = 19 pc) transiting extrasolar planet HD189733b, by measuring the flux decrement during its prominent secondary eclipse. A 6-hour photometric sequence using Spitzer’s infrared spectrograph in peak-up imaging mode at 16 μm shows the secondary eclipse depth to be 0.551±0.030%, with accuracy limited by NRC Postdoctoral Rese...