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A photovoltaic cell is nothing but a simple PN junction. There is an N-type semiconductor layer facing the sunlight. The P-type semiconductor sits below the N-type layer. Obviously, at the junction of the N and P-type semiconductors, there is a depletion layer. Theory of Depletion Layer The basic theory of the depletion layer at the … Read more
Scientists began producing monocrystalline silicon nearly a century ago. Scientist Jan Czochralski discovered the modern process in 1918. However, engineers had built the first silicon solar cell by 1941. Manufacturers follow eight simple steps for this process. Make Metallurgical Silicon Silicon is the main material in monocrystalline panels. It comes from silica sand or quartzite … Read more
A grid-connected rooftop solar power plant converts sunlight into electricity. It supplies power to a building. It also sends extra power to the electric grid. The system works step by step from left to right. Rooftop Solar Modules A Solar PV module contains a predetermined number of photovoltaic cells. Solar PV modules are installed on … Read more
A DC–DC converter is an electronic circuit. It changes one DC voltage level into another DC voltage level. It does this without changing DC to AC. Why is a DC-DC converter needed? Solar panels give variable DC voltages. Because the photovoltaic cells produce voltage depending on the intensity of sunlight. The load needs a fixed … Read more
A high-voltage power system deals with a huge quantity of currents. Unfortunately, the huge size of meters or protection relays is not available in the market. For cost and size optimization, the meters and relays are normally designed with a 1 A or 5 A rating. Therefore, there must be some means by which we … Read more
The current transformer is a kind of transformer that steps down currents. From the name “current transformer,” we can understand that it deals with current. The available instruments for measuring and protection purposes in the market are of a few amperes range. The ammeters, energy meters, wattmeters, and various protection relays are rated for only … Read more
Wound Type CT The Wound type CT uses a magnetic core. The core of the CT consists of laminations of cold-rolled, grain-oriented silicon steel. Some manufacturers also use nano-crystalline core material for this purpose. This creates a closed magnetic path. We wrap insulating paper around this closed magnetic path (core). Over the paper insulation, we … Read more
Organized into 15 categories Current Transformer (CT) Potential Transformer (PT / VT / CVT) Circuit Breakers (VCB / SF6 / GIS / ACB / OCB) Protection Systems Substation Engineering (AIS/GIS) Earthing & Lightning Protection Transformer Engineering Capacitor Banks & Power Quality Transmission Lines Distribution Systems HVDC & FACTS Industrial Systems Standards & Testing Real-World Operation … Read more
We mostly use self-supported towers for electrical EHV power transmission. A self-supported tower differs from other types because of its construction features. This tower does not require any stay wire or guy wire to keep it stable in the vertical direction. We generally use lattice-type towers made from galvanized iron (GI) angles of different sizes … Read more
In this article, we are going to discuss the dead tank CT or dead tank current transformer, commonly referred to as a dead tank CT. Dead tank current transformers are not popular for very high-voltage systems like 220 kV and above. Utilities often use dead tank CTs in 33 kV systems. They prefer this design … Read more
A live tank current transformer (Live Tank CT) is a high-voltage current transformer. Here we place the entire current transformer at the top of the device. If we imagine a current transformer, the primary of the current transformer is nothing but the line conductor. Because of that, we connect the primary in series with the … Read more
When it comes to high-voltage power systems, current transformers (CTs) play a critical role. It has a vital role in measurement and protection. CTs come in two main designs—Live Tank and Dead Tank. While both serve the same fundamental purpose, they differ significantly in construction. Live tank and dead tank CTs differ mainly in insulation. … Read more
Current Transformers (CTs) play a crucial role in power systems. They perform both metering and protection functions. However, the same CT can not perform both metering and protection functions. This is because each of the protection and metering applications has different accuracy, burden-handling, and dynamic performance requirements. Hence, CTs are designed as either Metering CTs … Read more
A current transformer (CT) reduces high currents to small, usable values. We utilize CTs for metering and protection purposes. Proper CT selection ensures accuracy, safety, and reliable protection. Identify the Purpose of CT Metering CT A metering CT measures current for billing and monitoring. Therefore, it must work accurately within the tolerable upper limit of … Read more
Lightning protection is essential in every high-voltage substation. The lightning masts (LMs) shield equipment from direct strokes. We use the DSLP calculation to check this shielding. We need three main inputs for this calculation. Calculate Single Mast Protective Radius A lightning mast protects a circular zone. Say, \(r_x\) is the radius of this protection zone … Read more
Here we have explain the topic on the magnetic effect of current or magnetic effect due to current. When an electric current flows through a conductor, it produces a magnetic field around it. Obviously, this phenomenon is the magnetic effect of electric current. What is a magnetic field? Actually, a magnetic field is the region … Read more
A Nickel Cadmium battery is a rechargeable chemical battery. It uses nickel oxyhydroxide as the positive active material. Also, it uses cadmium as the negative active material. Compared to other battery technologies it provides stable voltage, long cycle life, and reliable performance even under heavy load and low temperatures. Ni-Cd Battery Composition A Ni-Cd battery … Read more
An electrical protection relay is an intermediate device that bridges the function of a current transformer or a similar fault-detecting device to one or more circuit breakers. In other words, the relay connects the fault-sensing device with the fault-clearing device. Essentially, a relay has a simple magnetic coil that receives current from the current transformer. … Read more
An electromagnetic attraction type relay is the simplest form of protection relay. The relay uses an electromagnet to perform its function. Its basic construction consists of a magnetic core made of laminated, cold-rolled, grain-oriented silicon steel or laminated steel. Lamination reduces eddy current losses, while the cold-rolled structure of the iron minimizes hysteresis loss. We … Read more
We often refer to a contact multiplier relay simply as a contact multiplier. Also, we call it a contact multiplying relay or contact multiplication relay. It is a special type of electromagnetic attraction armature relay. Its function is to multiply the auxiliary contacts of a main relay. Sometimes, a protection relay does not have sufficient … Read more