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Chopper Fed DC Drives

Chopper Fed DC Drives: The variable voltage to the armature of a dc motor for speed control can be obtained from a dc chopper which is a single stage dc…

Three Phase Drives

Three Phase Drives: Single phase drives discussed in the previous section are employed for low and medium powers. When the power of the drive is very large the three-phase converter…

Synchronous Speed on Variable Frequency Supply

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…

Braking and 4 quadrants Operation

Braking and 4 Quadrants Operation: Subsynchronous converter cascades have been used, till now, in applications requiring one quadrant operation. These can be employed for drives where at least one electrical…

Chopper Resistance in the Rotor Circuit

Chopper Resistance in the Rotor Circuit: Speed control by means of slip variation can be achieved by employing a variable resistance Chopper Resistance in the Rotor Circuit. From the equations…

Features of Variable Voltage Inverters

Features of Variable Voltage Inverters: The inverter has an impressed dc voltage. The output voltage of the inverter is decided by the firing and duration of the thyristors. The conduction…

Three Phase Inverter

Three Phase Inverter: The variable frequency required for the speed control of three phase ac motors is obtained from a Three Phase Inverter. To avoid magnetic saturation and to obtain…

Chopper Controlled Resistance

Chopper Controlled Resistance: By interrupting the flow of current through a resistance R in a periodic fashion using a switch, the value of resistance can be effectively varied. The interruption…