Interview Questions on Substation Battery & Battery Charger

What is a VRLA Battery Bank? The full form of VRLA is “Valve Regulated Lead Acid”. Therefore, a VRLA battery means a Valve-Regulated Lead-Acid battery. It is essentially a modified version of a conventional low-maintenance lead-acid battery. Overchargings form oxygen and hydrogen gases due to electrolysis of water. These gases escape through vents provided on … Read more

Discharging and Charging Reactions of a Lead Acid Battery

Lead-acid batteries are the most commonly used battery bank systems in substations. This is a popular and robust rechargeable battery system. Before diving into the details of a lead-acid battery, we should first understand its basic charging and discharging cycles. Discharging Reaction of Lead Acid Battery During Discharging at Negative Pb Plates Diluted sulfuric acid … Read more

Power Frequency Withstand Voltage & Impulse Voltage Ratings

Normally, two kinds of overvoltage may appear in an electrical system. Power Frequency Withstanding Voltage One type is power-frequency overvoltage. In a three-phase system, a fault in one phase can increase the voltage in the healthy phases to an elevated value. This condition can continue until the clearance of the fault. Also, due to sudden … Read more

What is Inductance? Complete Guide for Electrical Engineers

Before explaining inductance, let us recall what an inductor is. An inductor is a passive device that opposes sudden change in current through it by inducing an emf across it. Actually, an inductor is a coil of conducting wire. When current flows through an inductor, it produces a magnetic flux around it. Hence, this flux … Read more

What is an Inductor? How does an Inductor Work in DC?

An inductor is any type of coil of a conductive wire. We all know from our childhood that when a current flows through a coil, it becomes a magnet. It means that whenever a current flows through the coil, it produces a magnetic flux surrounding it. Obviously, if we change the amplitude of the current, … Read more

Kirchhoff’s Current Law and Kirchhoff’s Voltage Law?

Kirchhoff’s Current Law and Kirchhoff’s Voltage Law are two very important laws for solving electrical circuit networks. We use these laws mostly to solve network problems. Kirchhoff’s Current Law Kirchhoff’s Current Law (KCL) says that the total current entering a node equals the total current leaving the node. Obviously, a node is a point where … Read more

Behavior of An Inductor in AC Circuit – Complete Explanation

In our previous article, we discussed how an inductor behaves in a DC circuit. In this article, we shall discuss how an inductor behaves in an AC circuit. Suppose there is an inductor. We have connected this inductor across an alternating electrical source. The alternating source generates a pure sinusoidal signal. Now, we shall consider … Read more

How to Enhance Transmission Capacity?

The power sector is growing rapidly nowadays. Therefore, we need to increase the capacity of electrical transmission systems to fulfil the rapidly growing demands. The most basic way to increase the transmission capacity is to construct new transmission lines. However, nowadays it become almost impossible to find new corridors for new transmission lines. The increased … Read more

What is Radio Interference Voltage(RIV)? How to Measure RIV?

When a corona discharge occurs around a high-voltage conducting part of any equipment or around conductors, RIV appears. The corona discharge is nothing but a partial discharge that happens in the air surrounding a conductor at a high voltage level. This corona discharge creates electromagnetic waves of very high frequency. This high-frequency electromagnetic wave is … Read more