Toroid Transformers and Its Concept

Toroid transformers, also called as Toroidal Transformer or Toroidal power supply are transformers having the shape of its core different than the conventional ones. Toroid transformer's core, as the name implies are toroids or called as Toroid Cores.
Toroids are ring-shaped surface generated by rotating a circle around an axis that does not intersect the circle. It is a doughnut-shaped object enclosed by a torus.


Learn the hows and whys behind basic electricity, electronics, and communications without formal training
The best combination self-teaching guide, home reference, and classroom text on electricity and electronics has been updated to deliver the latest advances. Great for preparing for amateur and commercial licensing exams, this guide has been prized by thousands of students and professionals for its uniquely thorough coverage ranging from DC and AC concepts to semiconductors and integrated circuits.


Transmission Lines Voltage Evolution and Selection
Electricity has been used as a major energy source since the late 19th century. The first three phase alternating current transmission started in 1891, a 175 km long line supplying electricity to an electrical engineering exhibition in Frankfurt and Main Germany. A power of about 200 kW was transmitted by this line operating at 40 Hz.

Since then, the selection of transmission voltage have evolved to facilitate the needs and requirements of the user. The evolution of voltage levels and other milestones can be seen below:


OPGW or known as Optical Ground Wire is a type of cable or wire that is used in transmission lines construction. It is also known as optical fiber composite overhead ground wire. It can serve as a grounding wire, shielding wire, and at the same time a cable used for communication purposes. 

OPGW contains a tubular structure with one or more optical fibers in it. It is then surrounded by layers of steel and aluminum wire. It can be compared like an ASCR, except that steel is the one covering the tube with fiber optics inside.


Transmission and Distribution Electrical Engineering is the engineer’s handbook to real-world power engineering practice – a unique working reference for the engineer, technician, systems planner and manager

Most books on transmission and distribution electrical engineering are student texts that focus on theory, brief overviews, or specialised monographs. Colin Bayliss and Brian Hardy have produced a unique and comprehensive handbook aimed squarely at practising engineers and planners involved in all aspects of getting electricity from the power plant to the user via the power grid.


The Electrical Engineer's Handbook is an invaluable reference source for all practicing electrical engineers and students. Encompassing 79 chapters, this book is intended to enlighten and refresh knowledge of the practicing engineer or to help educate engineering students. 



The longest single span in a transmission line in the world is found in Greeanland. We've already talked about the longest transmission line in terms of circuit kilometers on this blog entry. This is for the distinction in a single span.


Transmission Planning is purposed to define a transmission system or its expansions as to comply with the electric energy demand at specified quality and reliability criteria at a minimum cost. Planning process should be continuous, should have an interactive structure as to make an optimized future evolution use.

The planning studies take a leading role in the definition of an electric system or its expansion. The planning activities have to start several years before the installation of new or expansion of existing transmission lines is to be implemented.

Planning Stages of Transmission Lines

1. Long Term Planning - It defines the basic future structure of an electric system. It comprises a long term horizon for the system planning usually in the range of 15-30 years.

2. Medium Term Planning - Its target horizon is in the range of 10-15 years. It usually defines the basic characteristic of the system such as voltage, main transmission lines  and substations.

3. Operation or Short Term Planning - The horizon to be analyzed is usually below three years and urgent requirements of the system. These includes but not limited to the anticipation of operation dates of new facilities, needs to uprate or upgrade existing lines, or load transfers in scheduled interruptions.

Note: Planning should be continuously revised depending on the variation that can occur in the economic environment, the energy market, energy industry, or in the generation program.

Planning Aspects Regarding Transmission Lines

Planning Studies should answer the following questions:
When will a new transmission line, or uprating, or upgrading of existing lines will be required?
Where is it required and what quality of supply or reliability is required?
What normal and emergency ratings are required?
What type of transmission should be used? (Overhead, underground, AC or DC?)
What voltage and how many circuits will be needed?

Transmission Lines Planning Criteria

The basic criteria that should be established in a system planning is that no load can be lost under occurrence of a simple contingency in the system being studied or in another neighboring interconnected system.

Steady State Condition Criteria
The system must be tested for heavy load and light load conditions. It should support the outage of any of its components, also known as n-1 criterion.

Load flow studies parameters are as follow:
Voltage range should be between 0.95 and 1.05 p.u.
Transformer loads: Normal conditions: no overload
                             Loss of a transmission line or generator: 20% overload
                             Loss of a transformer: 40% overload

Temporary and Transient Condition Criteria
System stability is required under any load condition in case of phase to ground short circuit without reclosing, considering the loss of one of the system components.

Temporary over voltages should not cause damage to any system equipment. The maximum allowable temporary over voltages are in the range of 140% in points with saturable equipment and 150% in other points.

Short Circuit powers and currents have to be assessed as accurately as possible in order to prevent exceeding the equipment capacity of the system and installations.


How to Conserve Energy and Save Money in the Process?

Energy Conservation is a paramount duty of everyone. We know how much estimated electrical energy is consumed by the world from my previous entry. It also directly related to how much resources utilized and how much waste is emitted to the environment. In short, everyone must act and think of energy conservation.

Whenever you save energy, you not only save money, you also reduce the demand for such fossil fuels as coal, oil, and natural gas. Less burning of fossil fuels also means lower emissions of carbon dioxide (CO2), the primary contributor to global warming, and other pollutants.


Yup, you read it right. This is about the World's Longest Overhead Transmission Line as of today. It is around 1700 km in length, transmitting power of 560 MW. Interestingly enough it its transmission voltage is 500 kV dc, mainly due its relatively long distance.


Aluminum Conductor Steel Reinforced (or ACSR) cable is easily the most used type of cable in overhead power lines in the last century. It is a specific type of high-capacity, high-strength stranded cable used in overhead power lines where the outer strands are aluminum, chosen for its excellent conductivity, low weight, and low cost. Its center strand is of steel for the strength required to support the weight without stretching the aluminum due to its ductility. Thus the name steel reinforced. 


Conductor, classified further as wires or cables is one of the major components of your transmission lines system. A conductor is a material that facilitates the flow of electricity (or electric current) in our transmission line.

Different types of conductors are used in transmission lines. They vary in number and size, depending on the type of circuit and the transmission voltage. Steel, aluminum and copper are the most common conducting materials used in transmission lines.


PLS CADD ( Power Lines System – Computer Aided Design and Drafting) is a computer software that enables you to design, simulate, and analyze the behavior of a transmission and distribution system. It is owned and developed by Power Lines System, from which the name was derived. It is the most popular tool in transmission lines design, and fast becoming (if not yet) an industry standard.


Ohms Law is the basic of anything that has something to do with electrical engineering and electricity. It is a mathematical expression of the relationship between, the current, voltage, and resistance. Every equation and law in electrical engineering would be explained at the simplest sense, and would all boil down to Ohm's Law.

Ohms Law states that the current is directly proportional to the impressed emf applied to the circuit, and is inversely proportional to the resistance of the said circuit. This mathematical equation is conveniently represented by only three letters:

I = E/R
Where; I - current
E - voltage
R - resistance

Ohms Law was named after one of our Electrical Engineering Heroes, Georg Simon Ohm.

Enter two known values and press Solve to calculate unknowns.




Ohm's Law Components

Current or electric current is the motion of the electrical charges brought upon by a potential difference. It's unit is in ampere, named after Andre M. Ampere. One (1) ampere unit is equivalent to one coulomb of charge, passing a point in one second.

Impressed Electromotive Force (EMF), also called as Potential Difference, or simply voltage, is the capability of doing work, expressed in Volts. It is named after Alessandro C. Volta. One (1) unit of volt is equal to one Joule of work done per coulomb of charge.

Resistance is the inherent opposition of the conductor where the work  (one joule per coulomb) has to be done. Factors that determines the resistance aside may be its resistivity, area, length, and temperature.

Ohm's Law Sample Calculation and Practical Usage

a. A load of 10 ohms is connected to a source with 120 volts. What is the current drawn?
From ohm's law, I = E/R
    I = 120/10 = 12 amps

There you go. We hope that we gave you even just a little idea about Ohm's Law.
You may also visit recommended websites if you want to know more about one of the most important law in electricity, Ohm's Law.

Ohm's Law Calculator =


Daily electrical energy consumption of the world is quite an intriguing idea. But how exactly would you dtermine the daily electrical consumption of the world. On this feature, we try to estimate, and put into context the daily energy consumption of the world.


On this post, i will share to you a sample of a .bak file. Vertical dead end construction using strain insulators.

Download link is ==>HERE


Voltage Surge is an abnormal conditions on the Electrical Power System, characterized by voltage spikes. These usually refers to acute to extreme high voltages that is experienced by the power equipment.

Voltage surges could be transients or sustained. Whichever is the case, this could do harm to the electrical equipment or even your household appliances. Frequent transient surges and sustained over voltages is typically not good and should be kept minimal if not totally prevented. This will damage the insulation of such, and could result in electric flashover, which could not only do harm on the equipment but to lives as well.

Voltage Surges Causes

Common causes of voltage surges are; lightning and switching. Switching surges can be produced by the repeated igniting and extinguishing of electric arcs. Such voltage surges are obtained, for example, in disconnecting unloaded lines or by the grounding through an arc of one of the phases of a three-phase system with an insulated neutral conductor.

Lightning surges are voltage surges that are associated with lightning discharges either directly into the current-carrying parts of electric equipment (direct-strike surges) or into the ground adjacent to the equipment (induced surges). In a direct strike all of the lightning current passes into the ground through the struck object.

Voltage surge protection and suppression is one of the main engineering field of specialty in Electrical Engineering. One of the most important aspect in fact is called, insulation coordination.

For more on voltage surges and how to protect your equipment from it, you may refer to these articles:

Voltage Surge Effect on Motors
Damage from Voltage Surge 
Specifications of Voltage Surge Supressor
Transient Surge Protection for Low Voltage
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