Indepth Electrical engineering

Regenerative Braking in Induction Motors Braking of induction motors is essential for controlling speed, safety, and energy efficiency in industrial drives. Among the various braking techniques, regenerative braking is highly efficient since it converts the motor’s kinetic energy into electrical energy and feeds it back into the supply system. Principle of Regenerative Braking In a normal stator-fed induction motor , regenerative braking is possible if the number of poles of the machine can be changed during running conditions using special arrangements. This technique is applicable in squirrel cage induction motors since: Number of poles in the stator = Number of poles in the rotor (though not necessarily equal to the number of phases). Method of Operation Pole Changing Method When braking is required, the number of poles is increased (usually by a factor of 2). The synchronous speed of the revolving magnetic field reduces to half. Slip becomes nega...

⚡ Shunt Compensation Shunt compensation is a method of controlling system voltage by connecting shunt capacitors or shunt reactors directly to the transmission network. Shunt Capacitors → supply reactive power (kVAR) to the system, thereby raising voltage during light load or under-voltage conditions. Shunt Reactors → absorb reactive power, thereby reducing voltage during no-load or light-load conditions when the voltage tends to rise. 🔑 Engineering perspective: Simple, static, and reliable solution. Provides step-by-step voltage regulation since capacitor banks can be switched in or out. Widely used in transmission and distribution systems due to low cost and negligible maintenance. ⚡ Synchronous Phase Modifier (Synchronous Condenser) A synchronous phase modifier (also known as a synchronous condenser ) is essentially a synchronous motor running without mechanical load . When under-excited , it draws reactive power → acts like an inductor. When o...

Overcurrent Relays and Their Characteristics Overcurrent protection is one of the most widely used protection schemes in power systems. It protects equipment such as transmission lines, feeders, transformers, and generators against excessive current caused by short circuits or overloads. Depending upon the time of operation, overcurrent relays are categorized into the following types: Instantaneous Overcurrent Relay Inverse Time Overcurrent Relay Inverse Definite Minimum Time (IDMT) Overcurrent Relay Very Inverse Overcurrent Relay Extremely Inverse Overcurrent Relay Let us study each one in detail. 1. Instantaneous Overcurrent Relay Principle: Operates instantly (about 0.1 sec) when the current exceeds the preset value. Working: Achieved using hinged armature relays or solid-state relays without any intentional delay. Characteristic: A vertical line on the time-current curve. Application: Used for short...

Electrical Formulas Electrical engineering required certain formula which must be known for an electrical engineer and even a non engineer person so to know certain parameters of appliances around everyone. Lets discuss 1 st about basic parameters used in electrical systems:- I   =   Amperes E   =   Volts kW   =   Kilowatts kVA   =   Kilo volt-Amperes HP   =   Horsepower % eff . =   Percent Efficiency pf   =   Power Factor For Single-Phase load here are the formula’s as below:- TO FIND:- §   Amperes when kVA is known –>     I = kVA x 1000 / E §   Amperes when horsepower is known –>    ( HP x 746) / ( E  x  % eff.  x pf ) §   Amperes when kilowatts are known –>    ( kW x 1000 ) / ( E x pf ) §   Kilowatts  –>    ( I x E x pf ) /1000 §   Kilovolt-Amperes  –>    ( I x E ) ...