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What is resistivity? Understand specific resistance, its units (ohm-meter), how material, length, area, and temperature affect conductor resistance. Laws of Resistance The resistance offered by a conductor depends upon four major factors. Length of the Conductor: One factor is the length of the conductor. That means if we increase the length of the conductor without … Read more
Electrical resistance is the opposition to electric current flowing through a conductor. Simply put, it blocks or reduces the movement of electrons through a conductor. When an electric current flows through a conductor, electrons drift from one end to the other end of the conductor. During this drifting, the moving free electrons collide with atoms … Read more
Let us discuss the effect of temperature on resistance. When the temperature of a conductor increases, its resistance also increases. This relation is linear. In other words, the change in resistance is directly proportional to the change in temperature. Mathematical Relationship If R1 is the initial resistance of a particular resistor or conductor at T1 … Read more
German physicist Georg Simon Ohm published his remarkable findings in 1827. This was the relationship between voltage, current, and resistance. We refer to this as Ohm’s Law. What Exactly is Ohm’s Law? Ohm’s Law states that the current flowing through a conductor is directly proportional to the voltage across the conductor and inversely proportional to … Read more
Cause of Voltage Regulation Every electrical source has some internal or inherent impedance. It may be a battery, a transmission line, a power transformer, or any other device that can supply electric power. Due to this inherent impedance, there is always a voltage drop in that system. When we measure the voltage across the open … Read more
Two types of losses occur in a transformer. We refer to these losses collectively as losses in Transformers. These two losses are no-load losses and copper losses. We also often refer to the no-load losses as core losses. These losses occur due to the magnetic material of the core of the transformer. These losses include … Read more
Not only a power transformer, but all transformers have only two main parts. These are the windings and the core. All other parts associated with the transformer are just there to support the working of the transformer. Actually, the principle of a transformer is based on these two elements — the winding and the transformer … Read more
Traditionally, cold-rolled grain-oriented (CRGO) silicon steel has been widely used for the cores of distribution transformers and station service transformers due to its excellent magnetic properties and relatively low core losses. However, in recent years, a modern trend has emerged in the choice of core materials, especially for distribution transformers and, to some extent, station … Read more
In this article, we are going to discuss the theory behind a condenser bushing. We have mainly focused on how the capacitor grading improves the voltage distribution along the thickness of the insulation. We also call it a capacitor graded bushing. There are mainly two types of condenser bushings. These are the OIP bushing and … Read more
We also refer to a resin-bonded paper bushing or a synthetic resin-bonded paper bushing, respectively, as SRBP or RBP bushings, in short form. Before entering the actual discussion of resin-bonded paper bushings, let us understand the meaning of resin-bonded paper. What is the meaning of resin-bonded? We all know that paper is a cellulose material, … Read more
An OIP bushing uses concentric cylindrical capacitors in series between the central conductor and outer insulator housing of the bushing. An OIP bushing serves the same purpose as the other types of bushings do. That means it provides proper insulation between the live conductor and the grounded metallic tank of electrical equipment, such as power … Read more
Type Tests for the transformer Routine Tests on the Transformer Stage Inspection Tests On Core: On Coil On Tank Acceptance Tests
Current Transformers are essential for protection and measurement. To work correctly, they must reproduce primary current in a fixed ratio on the secondary side. However, CTs are not ideal. They suffer from three major types of errors. Ratio Error (Magnitude Error) in CTs The CT can not produce the exact scaled-down current. The actual secondary … Read more
A watt-hour meter-type induction relay is essentially a variant of an electromagnetic induction relay. Instead of only current or only voltage, it operates depending on the power input to the relay. Obviously, these relays require both the voltage and current of the system to operate. Power is the product of voltage, current, and power factor … Read more
A static electrical relay is a protection relay. It uses solid-state electronic circuits. Additionally, it does not contain any electromagnetic coils or moving parts. Therefore, we refer to it as a static relay. Basic Structure of an Electrical Static Relay A static relay operates using electronic components and circuits. For example, these components include diodes, … Read more
The High Impedance Bus Differential Protection is a very interesting subject to study. A busbar is a critical component in a power substation. It ensures the proper connection of all incoming and outgoing feeders to a single voltage level system. Obviously, if a fault occurs on the bus itself and does not promptly clear, it may cause permanent damage to the … Read more
A Numerical Protection Relay: Modern Power System Protection A numerical protection relay is a breakthrough in power system protection technology. Unlike electromagnetic relays and static relays, this relay uses microprocessor-based technology. It combines digital signal processing, advanced algorithms, and communication systems. Today, numerical protection relays form the backbone of modern power system protection schemes. What … Read more
For Battery Sizing Calculation First, we consider a single battery bank for DC power for the entire substation. In our case, the DC system is 220V; hence, we first set the voltage rating of our battery to 220V. Here, we need to note for future extension of the substation. Because once we installed the battery … Read more
A voltage transformer is a type of instrument transformer. We also call it a potential transformer. It reduces high voltage to a lower and measurable value according to its turns ratio. We need to measure the voltage in extra-high-voltage (EHV) systems. However, a normal measuring instrument cannot measure such high voltages directly. So, a voltage … Read more
A High Voltage Circuit Breaker (HVCB) is a crucial component in power transmission and distribution networks. Its primary role is to protect electrical equipment by interrupting fault currents within the system. Beyond safeguarding equipment, HVCBs are vital for maintaining the integrity of the power grid. They isolate faults effectively, ensuring that adjacent systems remain unaffected … Read more