What is a Vacuum Circuit Breaker? A Complete Theory

A vacuum circuit breaker is a current interruption device that uses vacuum as the arc-extinguishing medium. When the contacts open, the arc is quickly extinguished due to the absence of a proper medium in the vacuum. We commonly refer to a vacuum circuit breaker as a VCB. We’ll cover here how they work, why they’re … Read more

Testing of a Station Service Transformer as per Standards

Type Tests of a 33/0.415KV Station Service Transformer There are mainly three standards we follow for testing of a Station Service Transformer. These are IS : 1180 part 3 – 2021, CEA Guideline and CBIP Manual. Type Tests According to IS : 1180 part 3 – 2021 According to the latest version of IS 1180 … Read more

Reactive Power in Power Systems: A Complete Guide

We measure the reactive power in VAR. Obviously, here V stands for volts and A stands for amperes. Whereas, R denotes reactive. A power transmission network deals with much larger reactive power. So, normally, we express the reactive power in MVAR. Obviously, 1 MVAR equals one million VAR. What is reactive power? The reactive power … Read more

What is Transformer Differential Protection? Complete Guide

The transformer differential protection belongs to the unit protection scheme. A unit protection confines itself within a defined zone. A differential protection scheme compares the vector sum of currents entering and leaving the protected equipment. In other words, it uses Kirchhoff’s current law. Under healthy and external fault conditions, the currents entering and exiting the … Read more

Location and Connection of Capacitor Banks

Location of Capacitor Banks It is always desirable to connect a capacitor bank as close as possible to the load. This optimizes the use of the capacitor bank. Whenever we connect a load to the power system, the capacitor associated with that load also becomes connected to the system. The capacitor cancels out the reactive … Read more

Quality Factor & Dissipation Factor or Q Factor & D Factor

Let us have a detailed discussion on the Quality Factor and Dissipation Factor. We also call these two factors the Q factor and the D Factor. What is Quality Factor or Q Factor? The Quality Factor, or Q factor, is the dimensionless parameter that describes the efficiency and sharpness of the reactive components. The reactive … Read more

What is an LCR Meter? Working Principle of an LCR Meter

An LCR meter is an advanced measuring instrument. We use it to measure the inductance (L), capacitance (C), and resistance (R) of a circuit. It helps determine the precise values of capacitances, inductances and resistances. These are the three basic parameters of an electrical or electronics circuit. It can measure the three circuit parameters: inductance … Read more

Shunt Capacitor Bank and Series Capacitor Bank

Requirement of Capacitor Banks Let us first discuss the actual requirement of capacitor bank in the power system. Actually, inductive loads such as transformers, motors, reactors, transmission networks, etc., cause current to lag behind the voltage. This increases the phase angle between current and voltage which in turn reduces the cosine of that angle. The … Read more

Double Star Ungrounded Capacitor Bank

Why do we use capacitor banks in the system? Generally, these capacitor banks are connected in 33 kV systems. Normally, in a 33 kV system, we use a double star ungrounded capacitor bank. Before discussing the actual connection configuration of a double star ungrounded capacitor bank, let us recall the benefits of a capacitor bank in a … Read more

Details of Capacitor Units in a Capacitor Bank

Capacitor Elements A capacitor element forms the basic building block of a capacitor unit. It has two metal electrodes. A dielectric medium separates these electrodes. Engineers connect multiple elements in series or parallel to form a capacitor unit’s internal circuit. They join several units in series to match the system’s rated voltage. The required MVAR … Read more