Pole Amplitude Modulation (PAM) is a method used to control the speed of a three-phase induction motor by changing the effective number of poles. It is a versatile technique used to control the speed of a three-phase squirrel-cage induction motor by effectively altering the number of active stator poles. Speed Equation \[ N_s = \frac{120f}{P} \] …
Pole Amplitude Modulation (PAM) of Three-Phase Induction Motor Read More »
A bus (or busbar) is a node in a power system where generators, loads, and transmission lines are interconnected. For load flow analysis, buses are classified based on known and unknown electrical quantities. Basic Quantities Each bus is associated with four quantities: Voltage Magnitude (\(|V|\)) Voltage Angle (\(\delta\)) Real Power (\(P\)) Reactive Power (\(Q\)) Only …
In an electric power system, the distribution system is responsible for delivering electrical energy from substations to end consumers. Among the various types of distribution systems, the radial distribution system is the simplest and most widely used configuration, especially in rural and semi-urban areas. Introduction A radial distribution system is one in which each consumer …
In electrical engineering, the selection of conductor materials for electric wires and transmission lines depends not only on electrical properties but also on mechanical strength. One important mechanical property is the Ultimate Tensile Strength (UTS) of the conductor material. Copper and aluminium are the two most commonly used materials in electrical conductors. Their ultimate tensile …
Ultimate Tensile Strength of Copper and Aluminium Read More »
In electrical engineering, conducting materials such as copper and aluminium are widely used for manufacturing electric wires and cables. One of the important physical properties considered while selecting these materials is specific gravity. Specific gravity affects the weight, mechanical strength, and cost of electrical conductors, which are important factors in the design of power transmission …
In modern high-voltage and extra-high-voltage (EHV) transmission systems, the use of bundled conductors is common. Bundled conductors help reduce corona losses, radio interference, and surge impedance, thereby improving the power transfer capability of the transmission line. One important conductor arrangement used in EHV transmission is the Quad Bersimis conductor configuration. This configuration is particularly useful …
In power transmission systems, the concept of Surge Impedance Loading (SIL) plays an important role in understanding the power transfer capability of transmission lines. It is particularly important in the analysis and design of high-voltage transmission systems used in long-distance power transmission. SIL helps engineers determine the loading condition of a transmission line at which …
Surge Impedance Loading (SIL) of AC Transmission Lines Read More »
Large power generators used in thermal and hydroelectric power plants produce a huge amount of heat during operation. Efficient cooling is therefore essential to maintain the temperature of the stator and rotor windings within safe limits. One of the most effective cooling methods used in large turbo-alternators is hydrogen cooling. Hydrogen gas is used as …
In Control Systems, a Unity Feedback System is a closed-loop control system in which the feedback transfer function is equal to unity . In this type of system, the output signal is fed back directly to the input without any amplification or attenuation. Definition A unity feedback system is a feedback control system in which …
The efficiency of a DC motor is defined as the ratio of mechanical output power to the electrical input power supplied to the motor. It indicates how effectively the motor converts electrical energy into mechanical energy. Efficiency is an important parameter used to evaluate the performance of DC machines. Definition of Efficiency Efficiency \((\eta)\) of …