## Voltage Source Inverters (VSI) Operation | VSI Working Principle

The voltage source inverter is a somewhat older design and less expensive to implement. Various implementations of the VSI are also known as six-step, twelve-step, or even eighteen-step inverters. Voltage Source Inverters Operation  In the VSI, the switches are turned on and off at regular intervals to deliver rectangular pulses …

## Variable-Frequency Drive Working Principle | Variable-Speed Induction Motor Drive

The induction motor is basically a constant-speed motor, as it operates within 3% of the synchronous speed, which is determined by the frequency and number of poles in the machine: $\begin{matrix} {{n}_{s}}=\frac{120\times f}{P} & {} & \left( 1 \right) \\\end{matrix}$ Although torque at a given slip is proportional to the …

## Pulse Width Modulated Inverter | PWM Inverter

The Pulse Width Modulated (PWM) inverter offers the ability to change both the magnitude of the voltage and the frequency using a fixed DC voltage as the input. This means a diode rectifier can be used as the front end of the drive, which appears as a constant power factor load …

## Stepper Motor Types and Working

Stepper motors are close relatives of brushless DC motors. The brushless DC motor is used where continuous motion is required, such as a fan or a disk drive. The stepper motor, on the other hand, is designed to move infinite increments (steps) in either direction and to keep track of …

## Current Source Inverter Operation

Both the VVI and PWM are voltage-source inverters; i.e., they provide a voltage to the motor similar to what it would normally receive from the power system, except at variable frequency. Current Source Inverter Working A current- source inverter, on the other hand, acts as a constant current source to …

## Brushless DC Motor Working

A DC machine actually has an AC current in the armature that is rectified by the commutator and brushes. Brushes eventually wear out, requiring maintenance, and they produce carbon dust and possibly arcing while operating. Nevertheless, the characteristics of DC machines are often desirable. With the advances in power electronics, …

## Single-Phase Induction Motor Working

Figure 1 shows the cross-sectional view of a single-phase induction motor. Consider the motor in Figure 1 at standstill. Current is applied to the windings, establishing two counter-rotating waves. As they sweep past the rotor bars they both try to start the machine but they cancel each other out. Thus, …

## Types of Single Phase Induction Motors | Single Phase Induction Motor Wiring Diagram

Because residences and many commercial buildings have only single-phase power, single-phase AC induction motors have many applications. In the home, washers and dryers have a substantially single phase induction motor, about 1/3 horsepower. The typical no-frost refrigerator has three motors- one which is an integral part of the compressor unit, …

## Important Magnetic Units, Terms, Symbols, and Formulas

The following table presents important Magnetic Units, Symbols, and Their Formulas as a reference, or source of information. These formulas play a key role while dealing with magnetic circuits such as Transformers, Inductors. Term or quantity Symbol or abbreviation SI Unit and Formula Flux (lines) ϕ \[Weber\text{ }\left( Wb \right)=\frac{number\text{ …

## Solar Energy System Cost

A general method of calculation will start from the load energy requirements; determine the local insolation level and the worst month insolation and from this determine the sizing of the storage capacity. From this follows the array power and area, the battery capacity, and eventually the voltage regulator size respectively, …

## Electric Machine Efficiency and Losses

Regardless of which type of electric machine is chosen for a particular job, efficiency is important for several reasons. First, and perhaps most obvious, a less efficient machine will cost more to operate. Second, the losses in the machine are converted to heat, which raises the operating temperature of the …

## Synchronous Machine as Generator and Motor

Figure 1 shows a cross-sectional view of a salient-pole synchronous machine. The armature windings are shown as concentrated windings, but in reality, they would be distributed. Such machines can be operated either in Motor or Generator mode. Motor Operation For motor operation, a balanced three-phase set of voltages is applied …

## DC Machine Construction and Operation

Figure 1 shows elementary permanent- magnet machine. It is very similar to the AC machine; however, instead of a pair of slip rings to connect to the ends of the coil, there is a single split ring. Each end of the coil is connected to one-half of the ring, and …