MV Circuit Breaker Or Vacuum Contactor? (2)
Continued from first part: MV Circuit Breaker Or Vacuum Contactor? (Part 1) When applied properly, both medium-voltage circuit breakers and medium-voltage fused contactors should provide decades of reliable service. Applied incorrectly, either can lead to major… Read more
Jan 31, 2014 | Mohan Krishnasamy
MV Circuit Breaker Or Vacuum Contactor? (1)
To compare the application of medium-voltage circuit breakers and of fused contactors, we must understand the basic characteristics of each switching technology. Comparison presented here shows the major characteristics of medium-voltage circuit breakers and medium-voltage… Read more
Jan 29, 2014 | Mohan Krishnasamy
6 Simple Rules to Ensure Substation Safety
Another extremely important substation engineering aspect is associated with safety protection. It is fair to say that safety is always a No. 1 priority in substation design, operation and maintenance. Unlike the case where a… Read more
Jan 27, 2014 | Edvard
Dimensioning of Power Distribution Systems (2)
Continued from the first part: Dimensioning of Power Distribution Systems (1) Dimensioning of cable routes and devices follows the maximum load currents to be expected at this distribution level. As a rule: Ib max =… Read more
Jan 24, 2014 | Edvard
Power Transformer Capacitance and Dissipation Factor Test
The capacitance and dissipation factor test is an AC low voltage maintenance test and is very similar to the power factor test. While the transformer preparation is identical to the power factor test procedure, there… Read more
Jan 22, 2014 | Edvard
Dimensioning of Power Distribution Systems (1)
When the basic supply concept for the electricity supply system has been established, it is necessary to dimension the electrical power system. Dimensioning means the sizing rating of all equipment and components to be used… Read more
Jan 20, 2014 | Edvard
How to perform a power transformer turns ratio test
Power transformer turns ratio test is an AC low voltage test which determines the ratio of the high voltage winding to all other windings at no-load. The turns ratio test is performed on all taps… Read more
Jan 17, 2014 | Edvard
Automatic transfer switch (ATS) between two low-voltage utility supplies
Multiple utility services may be used as an emergency or standby source of power. Required is an additional utility service from a separate source and the required switching equipment. Figure 1 shows automatic transfer between… Read more
Jan 15, 2014 | Edvard
Calculating the short-circuit current across the terminals of a synchronous generator
Calculating the short-circuit current across the terminals of a synchronous generator is very complicated because the internal impedance of the latter varies according to time. When the power gradually increases, the current reduces passing through three… Read more
Jan 13, 2014 | Edvard
8 main disadvantages of HVDC transmission
Few weeks back I posted an article about advantages of HVDC over HVAC transmission systems. Advantages of HVDC are numerous and very well recognized, but like everything on this earth this system has other side… Read more
Jan 10, 2014 | Edvard
U.S. Renewable Energy – The Facts!
About 82% of the nation’s energy comes from fossil fuels, 8% from nuclear, and 9% from renewable sources. Wind is the fastest growing renewable source, but contributes only 1% of total energy used in the… Read more
Jan 08, 2014 | Edvard
Example of MV/LV network structure with dual fed main MV switchboard
Connected to article: Example of standard MV/LV network structure MV consumer substation; The main MV switchboard can be backed up by a generator set and it feeds two MV/LV transformers; MV switchboard can be GIS… Read more
Jan 06, 2014 | Edvard
Driving Distributed Energy with Smart Networks
The smart network will set up a virtuous cycle for distributed generators and energy storage devices. It will grow the market by opening up more niches where distributed energy is economically competitive. This growth will… Read more
Jan 03, 2014 | Edvard
Economic Evaluation of Transformer Losses
Transformer losses represent power that cannot be delivered to customers and therefore have an associated economic cost to the transformer user/owner. A reduction in transformer losses generally results in an increase in the transformer’s cost. Depending on… Read more
Jan 01, 2014 | Edvard
