Control of Electric Motors

Commutation in DC Motor: Commutation and commutator wear and tear of the dc motor must be given due consideration when the motor operates on solid state converters. Spark-less commutation must be aimed at. The reactance voltage and dynamically induced voltage in the coil undergoing commutation affect the rate of change of current in the coil. […]

Performance of DC Motors Operating on Phase Controlled Converters: The nature of the output voltage and output current of a phase controlled converters impains the performance of the dc motor operating on these con­verters. The output of the converter is in the form of pulses. The average voltage is superimposed by an ac ripple which

Torque Equation of DC Motor: When dc voltage is applied to the armature of a dc motor with its field excited by dc, a torque is developed and the armature rotates. It accelerates to a speed at which the emf induced in the armature conductors balances the applied voltage and the following Torque Equation of

Starting Methods of Synchronous Motor for LCI: It has been pointed out that a Starting Methods of Synchronous Motor for LCI, even though complicated in its construction, has an advantage that it can provide the necessary reactive power required by the inverter, except at low speed. Among all the drives possible with synchronous motor, Starting

Current Source Inverter with Forced Commutation: Current Source Inverter with Forced Commutation – As has already been discussed, the disadvantages of machine commutation are (a) limitation on the speed range (b) the machine size is large and due to overexcitation it is underutilised. CSI with individual commutation for feeding synchronous motor. 1.used for providing commutation

Current Source Inverter Fed Synchronous Motor Drive: A synchronous motor draws a stator current which is independent of stator frequency when V/f and E/f are maintained constant and armature resistance is neglected. The motor also develops constant torque. The flux also remains constant. Therefore, by controlling the stator current of a synchronous motor we can

Three Phase Synchronous Motor Fed From Cycloconverter: DC link converter is a two stage conversion device which provides a variable voltage, variable frequency supply. Variable voltage, variable frequency sup­ply can be obtained from a cycloconverter which is a single stage conversion equipment. The power circuit of a Three Phase Synchronous Motor Fed From Cycloconverter is

Voltage Source Inverter Fed Synchronous Motor Drive: An inverter fed synchronous motor has been very popular as a converter motor in which the synchronous motor is fed from a CSI having load commutation. Of late more attention is being paid towards understanding the behaviour of synchronous motors fed from a Voltage Source Inverter. These drives

Synchronous Speed on Variable Frequency Supply: As has already been discussed, the speed of a synchronous motor can be varied by supply frequency variation similar to an induction motor. The applied voltage must be varied in this case also to have the maximum torque capability and to avoid saturation at all frequencies. A Synchronous Speed

Synchronous Motor Drives: Variable frequency drives employing synchronous motor are receiving consid­erable interest, and are even becoming competitors to both induction motors and dc motors. These are popular as drives for very high power applications, such as pumps, fans, conveyors, etc. The stator of the synchronous motor is supplied from a thyristor power converter capable