Indepth Electrical engineering

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 ) ...

🔌 Power Transmission: Overhead vs Underground Cables ⚡ Key Electrical Aspect ·          Overhead Lines (OHTL): Inductance is predominant. ·          Underground Cables (UGC): Capacitance is predominant. ✅ Advantages of Overhead Transmission Lines 1.       Lower Conductor Cost: o     Overhead conductors run cooler in open air → smaller cross-section needed compared to underground. o     Results in cheaper conductor material. 2.       Cheaper Insulation: o     OHTL uses bare conductors, spaced by air (a natural insulator). o     UGC requires costly insulation: paper tapes, metal sheath, oil/gas filling, storage vessels. 3.       Lower Installation Cost: o     Poles/towers are cheaper to install than trenching and laying undergr...