Ferranti Effect is the rise in receiving-end voltage (VR) as compared to the sending-end voltage (VS) of a transmission line. It was first noticed by Sebastian Ziani de Ferranti on a project involving underground cables in a 10 kV distribution system in 1887, and was eventually named after him.
Monday, September 26, 2011
STATCOM or Static Synchronous Compensator is a shunt device, which uses force-commutated power electronics (i.e. GTO, IGBT) to control power flow and improve transient stability on electrical power networks. It is also a member of the so-called Flexible AC Transmission System (FACTS) devices. The STATCOM basically performs the same function as the static var compensators but with some advantages.
Friday, September 23, 2011
Static Var Compensator (SVC) is a power quality device, which employs power electronics to control the reactive power flow of the system where it is connected. As a result, it is able to provide fast-acting reactive power compensation on electrical systems. In other words, static var compensators have their output adjusted to exchange inductive or capacitive current in order to control a power system variable such as the bus voltage.
Monday, September 19, 2011
Power Quality Primer is an excellent reference, which provides description of power quality terminologies, problems and solutions. It aims to give utilities to become competitive in a deregulated power business, while educate customers for them to properly select the utility that meets their power quality requirements. Power Quality Primer outlines the fundamentals, to easily understand the needed concepts, for electrical engineers, consultants and prospective mitigators.
Sunday, September 18, 2011
There are several techniques available for Flicker Mitigation. However, since flicker is caused by voltage fluctuations, these methods should be based on reducing such power quality phenomenon. It must be noted that the effects of voltage fluctuations are dependent on both its amplitude and the rate of their occurrence. Generally, mitigation measures are focused on limiting the amplitude of the voltage fluctuations.
Saturday, September 17, 2011
The UIE/IEC Flickermeter is the standard for flicker measurement. Its main function is to provide assessment of the flicker perception caused by voltage fluctuations. Therefore, the flickermeter should be designed to have the capability of transforming the input voltage fluctuations into an output parameter proportionally related to flicker perception. This is done by simulating the process of physiological visual perception, which is the lamp–eye–brain chain.
Wednesday, September 14, 2011
The undesirable effects of voltage fluctuations on electrical and electronic equipment are briefly described here. This post aims to give an overview of these effects, which are more obvious with light sources. Nonetheless, other sophisticated devices subjected to voltage fluctuations could malfunction and have reduced efficiency, which are costly in terms of downtime and rejects.
Saturday, September 10, 2011
Voltage Fluctuations are described by IEEE as systematic variations of the voltage waveform envelope, or a series of random voltage changes, the magnitude of which falls between the voltage limits set by ANSI C84.1. Generally, the variations range from 0.1% to 7% of nominal voltage with frequencies less than 25 Hz. Subsequently, the most important effect of this power quality problem is the variation in the light output of various lighting sources, commonly termed as Flicker. This is the impression of instability of the visual sensation brought about by a light stimulus, whose luminance fluctuates with time.
Sunday, September 4, 2011
Handbook of Power Quality examines a full scope of PQ disturbances, including background theory and guidelines on measurement procedures and problem solving. Electrical engineers, consultants and even students who want to learn and gain knowledge on power quality issues and causes will find this book easy to read and understand, as it is well-written and organized. Also, Handbook of Power Quality is a good resource in that it contains many contemporary references for further in-depth study.
Friday, September 2, 2011
A Shunt Reactor is not yet included in the list of ETAP elements in its Edit Toolbar as of its latest version (ETAP 11). Nonetheless, it doesn’t mean that we can’t model a shunt reactor in our one-line diagram and simulation. Modeling a shunt reactor in ETAP is easy using a simple technique.
Thursday, September 1, 2011
Alessandro Volta made one of the greatest electrical discoveries of all time in 1796. He was able to produce continuous electric current for the first time, through his voltaic pile. Basically, it was the first electric battery and the first source of direct current (DC).
- I am a Professional Electrical Engineer with a Masters Degree in Business Administration. My interest is in Power Quality, Diagnostic Testing and Protective Relaying. I have been working in an electric distribution utility for more than a decade. I handle PQ studies, power system analysis, diagnostic testing, protective relaying and capital budgeting for company projects.