Machines are devices that convert energy from one form to another, especially between electrical and mechanical energy. In electrical engineering, machines play a vital role in power generation, transmission, industrial automation, and everyday applications.
This category covers electrical machines such as motors and generators, explaining their construction, working principles, types, characteristics, losses, efficiency, and applications. The content is designed to help students, technicians, and engineers understand both theoretical concepts and practical operation of electrical machines used in real-world systems.
Tap Changing Transformer is an electro-mechanical device. All the electrical equipment we use today is designed to function properly at a specific voltage level. However, the power supplied to electrical equipment can sometimes exceed or exceed its rated voltage. This can be due to a variety of factors, such as voltage drops in distribution lines … Read more
What is the Cooling of Transformers? Cooling of transformers is the process by which the heat generated in the transformer windings and core is safely removed to prevent overheating, insulation damage, and failure.This heat is mainly produced due to I²R losses, hysteresis losses, and eddy-current losses. Transformer Cooling Methods The main methods used to cool … Read more
Introduction. A transformer is considered the backbone of the power system. It helps transfer electricity safely and efficiently from one voltage level to another. But before any transformer is commissioned in a real power network, certain standard tests are carried out to check its safety and efficiency. These open and short circuit test of transformer, … Read more
Introduction Transformers are essential electrical machines that require proper testing to ensure reliable operation, efficiency, and safety. Several testing methods are used to analyze transformer performance, such as: 2. Importance of Direct Loading Test on a Transformer Performance Evaluation The Direct Loading Test on a transformer holds special significance because: This test directly measures input … Read more
Introduction A transformer is one of the most vital electrical machines used in power systems. Its primary role is to step up or step down voltage levels, making power transfer more reliable and economical. Transformers ensure smooth and efficient power transmission from generating stations to end users, reducing waste and maintaining system stability. The transformer’s performance … Read more
1. Introduction Transformers are vital components in electrical power systems, used to step up or step down voltages efficiently. However, a real transformer is not perfect — it has losses and non-idealities. The equivalent circuit is a simplified model that represents these imperfections, helping engineers analyze and design transformers effectively. 2. What is an Equivalent … Read more
1. Introduction A transformer is a key device in electrical power systems. It moves electrical energy from one circuit to another using electromagnetic induction. In an ideal world, transformers would work perfectly with no losses or voltage drops. But in real life, they have limits. One important factor is leakage reactance. This affects how well … Read more
Operation of Transformer in On-Load Condition To understand the operation of a transformer in load, let us first recall its on-load condition. In the on-load state, when an input voltage is applied across the primary winding, a small on-load current flows. This current establishes a magnetic flux in the transformer core. What is a Transformer? … Read more
Difference Between Ideal and Practical Transformer When it comes to learning about transformers, two terms often pop up: ideal transformer and practical transformer. They sound similar, but there’s a big difference between them. Let’s explore it in a way that’s easy to understand. What is a Transformer? A transformer is an electrical device that transfers … Read more
Understanding the brake test of dc motor: Imagine trying to find out how well a DC motor is working—how much of the electrical power it uses turns into useful mechanical work. One easy and direct way to check this in a lab is by do something called a Brake Test. Let’s break it down in … Read more
Three-Point Starter A three-point starter is commonly used to safely start DC shunt motors. Just like the two-point starter, it controls the high inrush of current when the motor is switched on. But this one comes with an added feature—overload and no-voltage protection, making it more reliable. What is a Three-Point Starter? The name “three-point” … Read more
DC Motor Starter: DC motors, especially those below 1 HP (0.746 kW), can often be directly connected to a power supply. This is possible because smaller motors have a relatively high armature resistance (Ra), which naturally limits the starting current. Some examples include: However, this direct online starting method cannot be used with larger motors … Read more
What Is Speed Regulation? Think about riding a bicycle. When you’re going downhill with no backpack, it’s super fast and smooth. But going uphill with a heavy bag? How to calculate the speed regulation of DC motors? DC motors act the same way. When there’s no load, they run fast. When there’s a heavy load, … Read more
Complete Guide to Swinburne Test DC Machine The Swinburne Test is a simple and useful method to check the performance of DC motors. It helps us know how much energy the motor uses and how efficient it is. This guide will explain everything in a very simple way. Let’s learn step by step! 1. Step-by-Step … Read more
How to Speed Control of DC Shunt Motors: While controlling the speed of a DC shunt motor may seem like a daunting task, with a little bit of guidance, it can be very simple. This tutorial will break this down step by step with simple language and relevant illustrations. 🔌 A DC Shunt Motor: A … Read more
What is DC Motor Speed Control? Every electric motor has a fixed speed written on its nameplate. This is called the rated speed. It tells us how fast the motor is supposed to run when it’s working normally. But in real life, things keep changing. When the load on the motor changes — like if … Read more
Compensating Winding When a motor or generator is working, the current inside the armature (the rotating part) keeps changing, especially when the load changes suddenly or becomes too heavy. These changes in current create something called a cross magnetizing effect, which means the magnetic field gets pushed to one side. Now imagine this — every … Read more
Armature Reaction – Definition When a motor or generator is running, there are two types of magnetic fields inside it. One magnetic field comes from the main field winding (which is supposed to be there), and the second one comes from the armature winding (the rotating part). Now, when the armature winding carries current, it … Read more
What is a DC Generator? A DC Generator is a machine that makes electricity. But not just any electricity — it makes DC electricity, which means Direct Current. Let’s make it super easy to understand. Imagine you have a toy fan that runs on batteries. The batteries give it power in one single direction — … Read more
key phase Transformers work on the principle of mutual induction. They have primary andsecondary windings that are electrically isolated from each other. As these windingsare wound on the same magnetic core, they are magnetically coupled to each other. The magnetic core is made from the laminations of either CRGO silicon steel or theamorphous alloy. … Read more
Introduction Single phase power system is widely used as compared to three phase system for domesticpurpose, commercial purpose and to some extent in industrial purpose. As the single phase system ismore economical and the power requirement in most of the houses, shops, offices are small, this can beeasily met by single phase motor. The single … Read more
Basic Alternator Working Principle: WHAT IS ALTERNATOR? Alternating current generators are usually called alternators. They operate on the principle ofFaraday’s laws of electromagnetic induction. This law states that whenever a conductor cuts the magneticflux an emf is induced in it. This emf causes a current to flow if the circuit is closed. Fig 1.1 shows … Read more
INTRODUCTION In the year 1821 British scientist Michael Faraday explained the conversion of electrical energyinto mechanical energy by placing a current carrying conductor in a magnetic field which resulted in therotation of the conductor due to torque produced by the mutual action of electrical current and magneticfield. Based on his principle the most primitive of … Read more
Transformer Safety: Transformers play a big role in powering our industries. They help move electricity safely and efficiently. They are helpful in many ways, but if not used properly, they can also cause harm Working with transformers can lead to serious risks. Electric shocks, arc flashes, and even fires or explosions can happen if safety … Read more
