Category: INDUCTION MOTOR DRIVES

Linear Induction Motor Working Principle

Linear Induction Motor Working Principle: While the conventional induction motor gives rotary motion, a Linear Induction Motor Working Principle provides translational or linear motion. Hence it is termed linear induction motor. To understand the principle of operation let us examine stator of the rotary induction motor (Fig. 6.66(a)). Let the stator be cut and unrolled […]

Single Phase Induction Motors Working Principle

Single Phase Induction Motors Working Principle: Single Phase Induction Motors Working Principle are inferior in performance and lager in weight and volume compared to three-phase motors of the same rating. However, they are simple, robust, reliable and less expensive for small ratings. They are employed in low power drives in small industries and domestic and […]

Variable Speed Constant Frequency Generator

Variable Speed Constant Frequency Generator: Variable Speed Constant Frequency Generator (VSCF) involves generation of electrical power at fixed frequency and fixed voltage from a variable speed prime mover coupled to the generator shaft. Wind generator is one such example. Speed of rotor varies with velocity and pressure of the wind, but power delivered to the […]

Current Regulated Voltage Source Inverter

Current Regulated Voltage Source Inverter: Current Regulated Voltage Source Inverter operates with current controlled PWM. In current controlled pulse-width modulation, machine phase current is made to follow a sinusoidal reference current within a hysteresis band. Fig. 6.48(a) shows a sinusoidal reference current i*A = Im sin ωt. Two bands, separated from i*A by an amount Δl, are shown in […]

Current Source Inverter Control of Induction Motor

Current Source Inverter Control of Induction Motor: A thyristor Current Source Inverter Control of Induction Motor (CSI) is shown in Fig. 6.45. Diodes D1-D6 and capacitors C1-C6 provide commutation of thyristors T1-T6, which are fired with a phase difference of 60° in sequence of their numbers. It also shows the nature of output current waveforms. Inverter […]

Variable Frequency Control From Current Source

Variable Frequency Control From Current Source: Control of induction motor employing variable frequency voltage sources was considered in previous section. This section considers motor control by Variable Frequency Control From Current Source (VFCS). An equivalent circuit for motor fed from a current source is obtained when voltage source V is replaced by a current source […]

Cycloconverter Control of Induction Motor

Cycloconverter Control of Induction Motor: Cycloconverter Control of Induction Motor allows variable frequency and variable voltage supply to be obtained from a fixed voltage and frequency ac supply. A half-wave Cycloconverter Control of Induction Motor is shown in Fig. 6.42 along with the nature of its output voltage waveform. Because of low harmonic content when […]

Voltage Source Inverter Control of Induction Motor

Voltage Source Inverter Control of Induction Motor: Variable frequency and variable voltage supply for induction motor control can be obtained either from a voltage sourve inverter (VSI) or a cycloconverter. Voltage Source Inverter Control of Induction Motor are described here and cycloconverter fed drives. VSI Induction Motor Drives: Voltage Source Inverter Control of Induction Motor […]

Variable Frequency Control of Induction Motor Drive

Variable Frequency Control of Induction Motor Drive: Variable Frequency Control of Induction Motor Drive – Synchronous speed, therefore, the motor speed can be controlled by varying supply frequency. Voltage induced in stator is proportional to the product of supply frequency and air-gap flux. If stator drop is neglected, terminal voltage can be considered proportional to […]