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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
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
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
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
The article will focus on the contact design of vacuum interrupters. Before discussing the subject, let us consider why a specific design of contacts is required. The simplest form of contact is the butt-type contact, which has a plain and flat surface. This type of contact is suitable for vacuum circuit breakers with a rated … Read more
Formation of Arc in Medium Before discussing the vacuum arc, let us recall the concept of arc formation in a medium like air, gas, or any other similar medium. Arc during closing contacts Let us switch on a circuit breaker online. Closing of this circuit breaker connects a load to a source. During closing, the … Read more
Before discussing the actual comparison, let’s look at the different media used in circuit breakers. These are air, oil, and SF6 gas. Nowadays, engineers have also developed some other gaseous media like compressed air, C4-FN mixtures (C4-FN/CO2 or C4-FN/N2), C5-FK mixtures (C4-FK/air or C4-FK/CO2), and pure N2 or N2/CO2 mixtures as insulating mediums. Certainly, some … Read more
We shall cover the constructional details of a vacuum interrupter along with its function, how it facilitates arc quenching, etc. Introduction to Vacuum Circuit Breakers Before entering into the detailed discussion about the vacuum interrupter, let us have a look at the basic concept of vacuum circuit breakers. A vacuum interrupter, which we also call … Read more
Introduction In modern medium-voltage power systems, vacuum circuit breakers play a dominant role in safe and efficient current interruption. Engineers prefer these breakers for their robustness, low maintenance requirements, and high dielectric recovery strength. A vacuum circuit breaker, also known as VCB, uses the unique properties of a vacuum to quench electrical arcs. Unlike SF6 … Read more
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