Javascript Code to Disable “Select All (Ctrl+A)” and “Copy (Ctrl+C)” for both Firefox and Internet Explorer

This is useful in preventing outright copying of webpage content through keyboard controls like Ctrl+A for “Select All” and Ctrl+C for “Copy”. Just paste this code on the “head” of the html code - before the “body”. Read the rest of this entry »

Why Online Partial Discharge Analysis Monitor is Unnecessary for Power Transformer

Partial Discharge Analyzer (PDA) is used to determine if there is or what is the level of partial discharge activities in the insulation of a power transformer. Read the rest of this entry »

What are Coincident Peak Demand and Non-coincident Peak (NCP) Demand?

In electric power distribution and transmission system, coincident peak demand is the demand of individual customers or sub-systems that coincides (in time) with the peak demand of the whole system. Read the rest of this entry »

Substation/Switchyard Bus and Breaker Arrangement/Configuration Reliability, Flexibility and Cost Comparison

Single Bus
This arrangement involves one main bus with all circuits connected directly to the bus. The reliability of this type of arrangement is very low. The maintenance of the bus and breakers would require the outage of the total system and the line. Read the rest of this entry »

What is the safe amount of current (electricity) that can flow into the human body?

According to IEEE Std 1246™-2002; Read the rest of this entry »

Transformer Cooling Classes

Voltage and current transformation in a power transformer involves a significant quantity of electrical energy losses. Such losses are the losses in the core and copper winding which are dissipated into heat. Read the rest of this entry »

Typical Electrical System in a Thermal Power Plant

The diagram below shows a Single Line Diagram (SLD) of the typical Electrical System in a thermal power plant. Read the rest of this entry »

When was the First Transformer been Constructed and called “Transformer”?

Would you wonder who gave the name “transformer” to a transformer?

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What is the “8 degree C (Celsius) rule”?

The “8 deg Celsius rule” (”8 ° C Rule”) is a known “rule of thumb” for estimating the thermal life of insulation of a transformer and thereby the transformer life itself. Read the rest of this entry »

The (Transformer) Short-Circuit Impedance Test

The short-circuit impedance (%Z) of power transformers is sometimes measured on site and it can be compared to the nameplate of factory test values. It is used to detect winding movement that may have occurred since the factory tests were performed. Read the rest of this entry »

How to Compute The Power Transformer Resistance And Reactance Given The Percent Impedance?

If you happen to see a power transformer nameplate, it is very rare (or impossible) to see the value for the resistance and reactance for the equivalent circuit of that transformer. The only valuable information that you can get from the transformer nameplate for this purpose is the percent impedance (%Z) and the voltage rating. Read the rest of this entry »

A Survey/Compilation of (Power) Transformer Percent Impedances (%Z)

Transformer impedance is one of the important information that is needed for the transmission line modeling for power flow, short circuit and other various power system simulations, Read the rest of this entry »

What are the Electric Power System Ancillary Services?

Magat Hydroelecric power plantAncillary Services are support services in the power system, particularly, those which are necessary to support the transmission capacity and are essential in maintaining power quality, reliability and security of the grid. Read the rest of this entry »

How Geothermal Energy is Converted into Electric Power?

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Turn-Around Efficiency of Hydrogen (H2) Powered Electric Power Plant

The turn-around efficiency of a hydrogen (H2) powered electric power plant is the overall efficiency of extracting hydrogen (h2) molecules from water, store it, and use that hydrogen to generate electricity. Read the rest of this entry »

What are the Different Types of Transformers?

Transformer is composed of two windings (or three windings for three-winding transformer or a single core three phase transformer) whose main purpose is to step-up or step down an AC voltage and AC current. Transformers can be called differently depending on its function, capacity, and construction; Read the rest of this entry »

(Transformer) Dissolve Gas Analysis (DGA) Testing

Since everything inside a power transformer is emerge in oil, which serves as its insulation and cooling medium, every activities or incidents inside the transformer tank leaves a signature or traces in the oil. Read the rest of this entry »

(Transformer) Oil Chemical Tests

Oil in Power or Main Transformers serves as a cooling medium and insulation for the windings. The main purpose of the oil chemical tests is to determine and monitor the chemical properties of oil, which is very essential for its purpose, since failure in such chemical properties could be disastrous for the transformer itself. Read the rest of this entry »

Can permanent magnet loss its magnetism or be demagnetized?

Well, according to Wikipedia, YES! To quote; Read the rest of this entry »

Open Circuit Test, Not Applicable For Transformers in High Voltage Application?

Many of new electrical engineers may thought that the open circuit test to determine the no load loss of a power transformer is always applicable to any kind of transformer. In the case of the high voltage application transformers, this is false. In high voltage application transformers, the number of turns of the high voltage winding is very high such that its capacitance (between windings and the ground) is not negligible. In fact, its value may reach 20 or 25 percent of the nominal load of the transformer. Read the rest of this entry »

How To Block Referrers And Disallow Hotlinking And Downloads From External Websites

Hotlinking (direct linking to a web site’s files - images, video, etc.) and downloads from external websites without your permission is an obvious bandwidth theft. Read the rest of this entry »


Aggregate_jcm is a slightly modified version of Rob Miller’s Aggregate which allows you to place the title, link and content of an RSS feed into your posts. This modified version can show the RSS feed content along with the post’ s summary or full text. Live demo here: Read the rest of this entry »

Where and How to find Free IEEE Standard and Paper Downloads

IEEE offers lots of good papers and references for your projects and research, however, IEEE publications are downloadable exclusively for its members only. Sometimes, access also depends on the level of membership in the organizations. Membership fees range from USD 131 to USD 165. It’s not that high though, but if you will only need one to two papers for your project, I think it’s not worth the cost. Read the rest of this entry »

Three Dark-Lamp Method of Synchronizing a Generator to the Grid

Unlike DC generator, synchronous generator, which is the commonly used type of generator for power plants around the world, need to have the same frequency and in-phase to the grid frequency before connecting. This is also the reason why the act of interconnecting a synchronous generator to the Transmission Grid is synchronization.
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Geothermal Energy: Renewable or Not?

Heat energy resource or geothermal resource below Earth’s crust can be utilized for electric power generation and for water heating purposes. Based on the record, the United States is the world’s largest producer of geothermal energy, and followed by the Philippines.
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Typical Electric Generator Efficiency

Electric generator losses usually include the same kind losses as of the power transformer, copper losses in the winding and magnetizing losses in the core, plus the rotational losses.
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The Backward Forward Sweep Load flow for Three-phase Unbalance Radial Distribution System

The algorithm for the backward-forward sweep power flow simulation for three-phase unbalance radial distribution system was formulated by D. Shirmohammadi and C. S. Cheng on their paper for the IEEE Transactions on Power Systems. The algorithm is quite simple since it was only based from the two basic laws in electrical engineering, the kirchhoff’ s current and voltage laws. Read the rest of this entry »

How to Run a Stand Alone Borland C++ Application

Borland C++ Builder (BCB) is a good tool for all range (both object-oriented and/or dynamic) of applications that require a utilization of a graphical user interface (GUI). Traditional C/C++ programs can also be easily integrated with the drag-and-drop tool used for creating a graphical user interface.
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Step by Step Procedure to Run a Power Flow Simulation Using PSSE

The Siemens - PTI PSSE power flow simulator is a well known and reliable power flow simulation tool for simulating power systems of up to large scale in size. However, just like other sophisticated analysis tools, it’s hard to learn the basics of using it, specially, for the new user of the software.
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Consider Inflation Rate When Doing Bank Deposits

Many people believed that doing deposit in the bank will earn them extra money from interest from their deposit, thus gaining them more wealth. Read the rest of this entry »