Electric Motor
Advantages of Variable Speed Motors
Most motors are designed to operate at a constant speed and provide a constant output. While in many cases this may be more than adequate, it is not in all. Two-speed induction motors can improve efficiency for refrigerators, air conditioners,… Read more
Jun 13, 2012 | By Edvard Csanyi
Transformers
Scott-T Transformer Connection Overview
There are two main reasons for the need to transform from three phases to two phases: to give a supply to an existing two phase system from a three phase supply and to supply two phase furnace transformers from a… Read more
Jun 12, 2012 | By Jignesh Parmar
Transformers
Star-Delta Transformer Connection Overview
In this type of transformer connection, then primary is connected in star fashion while the secondary is connected in delta fashion as shown in the Figure 1 below. The voltages on primary and secondary sides can be represented on the… Read more
Jun 10, 2012 | By Jignesh Parmar
Smart Grid
Smart Grid Communications Overview
An electricity grid without adequate communications is simply a power “broadcaster.” It is through the addition of two-way communications that the power grid is made “smart.” Smart grid communications enables utilities to achieve three key objectives: Intelligent monitoring, Security, and… Read more
Jun 09, 2012 | By Edvard Csanyi
Hydropower
Lester Allan Pelton – The father of hydroelectric power
Pelton was born in Vermilion, Ohio, in 1829. At age 20 he set out by foot to cross the plains and strike it rich. The first fourteen years he spent mining and wasn’t very successful. He moved to Camptonville and… Read more
Jun 08, 2012 | By Edvard Csanyi
Energy and Power
MCB – Miniature Circuit Breaker Construction
The miniature circuit breaker (MCB) plays an important role in providing overcurrent protection and a disconnect means in electrical networks. Recent advancements in circuit breaker technology has increased breaker performance and protection. A breaker is a device designed to isolate a circuit… Read more
Jun 07, 2012 | By Edvard Csanyi
Electrical Lectures
Fundamental Characteristics of Circuit Breaker
The fundamental characteristics of a circuit breaker are: Its rated voltage Ue Its rated current In Its tripping current level adjustment ranges for overload protection (Ir or Irth) and for short circuit protection (Im) Current-level setting values which refer to the… Read more
Jun 05, 2012 | By Edvard Csanyi
Energy and Power
Understanding Vector Group of Transformer (Part 2)
Vector Groups are the IEC method of categorizing the primary and secondary winding configurations of 3-phase transformers. Windings can be connected as delta, star, or interconnected-star (zigzag). Winding polarity is also important, since reversing the connections across a set of… Read more
Jun 04, 2012 | By Jignesh Parmar
Electrical Lectures
Understanding Vector Group of Transformer (Part 1)
Three phase transformer consists of three sets of primary windings, one for each phase, and three sets of secondary windings wound on the same iron core. The vector group of the transformer is determined by the connection between the windings… Read more
Jun 03, 2012 | By Jignesh Parmar
