141 |
An Unconventional Electrical Machine for Handling Molten AluminiumBamji, P. J. F. January 1976 (has links)
No description available.
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142 |
Thyristor and Diode Controlled Variable Voltage Drives for Three-Phase Induction MotorsRahman, S. January 1976 (has links)
No description available.
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143 |
Three dimensional field determination in superconducting synchronous generatorsSakr, S. M. M. January 1977 (has links)
No description available.
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144 |
Speed Control of Induction Motors using Modulated Supply VoltagesGogani, E. S. January 1975 (has links)
No description available.
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145 |
A novel technique for improving the performance of phase-controlled convertor systemsMukhopadhyay, S. K. January 1974 (has links)
No description available.
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146 |
The stability and optimisation of electric vehicle systemsEren, H. January 1978 (has links)
No description available.
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147 |
Control of a brushless permanent magnet machine using an integrated torque sensor in place of a rotor position sensorAlrifai, Fayez January 2011 (has links)
The work presented in this thesis proposes the use of measured torque feedback from an integrated, low cost surface acoustic wave (SAW) torque transducer in place of a position sensor to control brushless permanent magnet (BLPM) machines. The BLPM machine closed loop control requires knowledge of the rotor position to control stator current and maximum torque per ampere. The electrical position feedback to control the phase current requires a position sensor or position sensorless technique. Position sensors such as absolute encoder or resolver are needed for position information, in the absolute encoder, an accurately patterned disk rotates between a light source and a detector giving a unique digital output signal for every shaft position. However, each bit in the digital world represents an independent track on the encoder disk, resulting in a complex and costly sensors. Brushless resolvers operation is based on inductive coupling between stator and rotor winding. The resolver with its resolver to digital converter also gives precise absolute position information, but again the cost is often prohibitive. So the disadvantages of the position sensors are the added cost and size to the machine. The position sensorless techniques for the BLPM machine are based on obtaining position from the terminal voltages and currents based on estimating the back electro-magnetic force (EMF), flux-linkage or inductance which from position can be estimated. The disadvantages of the back-EMF and flux-linkage techniques are (1) that they behave poorly at zero and low speed (2) behave poorly for load disturbances since load torque is estimated from machine parameters which can change. The inductance techniques work at zero and low speed, however the disadvantages are (1) in a surface mounted machine there is no saliency so any variation of winding inductances with rotor position arises from magnetic saturation; (2) the back-EMF dominates the rate-of-change in the current; (3) the variation of incremental inductances with rotor position undergoes two cycles per single electrical cycle of the brushless pm machine causing an ambiguity in sensed position; (4) the distortion due to the nonlinearities in the inverter; (5) the load offsets and the noise caused by signal injection. This thesis develops a start-up routine and operation algorithms that enhance the performance of position sensorless control of brushless permanent magnet machines at all speeds, including zero speed, and loads by using a machine integrated, low-cost, SAW torque transducer in place of the rotor position sensor.
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148 |
Idiomatic integrated circuit designBergmann, Neil January 1984 (has links)
No description available.
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149 |
A quantitative voltage contrast test and measurement systemGilhooley, Bernard January 1984 (has links)
No description available.
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150 |
Time delay tracking using correlation techniquesKiani-Shabestari, Bijan January 1983 (has links)
No description available.
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