By Roman Targosz / Published on Wed, 2010-02-03 17:56
Leonardo ENERGY is launching a comprehensive e-learning multi-course on Power Quality.
The list of courses:
Read full story
By Roman Targosz / Published on Tue, 2010-01-12 11:43
Leonardo ENERGY Academy launches its e-learning initiative with a comprehensive programme on power quality. The first course introduces the topic of power quality and then focusses on voltage dips and short interruptions.
The course should take between 12 to 20 hours for participants with an electrical engineering background. Participants are expected to finish the course by the end of February (28-02-2010).
Read full story
By Isabelle Heriakian / Published on Mon, 2009-11-02 13:36
A semiconductor plant experienced a problem where the LV side main circuit breaker was tripped by voltage dips. As a result, power to all connected loads was interrupted and manufacturing processes were halted. The main cause of this problem was the unsuitable design of the under-voltage protection system. When a voltage dip occurred it was misinterpreted as an under-voltage event by the protection system, which erroneously tripped the circuit breaker.
Read full story
By Hans De Keulenaer / Published on Wed, 2009-09-02 14:54
This paper presents the effects of voltage sags on domestic and office equipment and provides equipment sensitive curves for safe and reliable operation based on the experimental results.
With the increased usage of sensitive electronic equipments in various industries, offices and household appliances, it is important to protect them from any power quality disturbances to avoid unnecessary losses of any kind. From the several types of power quality disturbances, the most frequent and concerning for electric utilities from a customer point of view was voltage sag.
Read full story
By Isabelle Heriakian / Published on Thu, 2009-01-29 10:19
In this guide, a design engineer works on a converter drive design and determines the voltage change coefficient during the drive start, compares it to permissible levels and suggests solutions to have it satisfying the limit.
Read full story
By Bryony Samuel / Published on Wed, 2008-12-03 10:48
This Application Note discusses some of the established techniques for voltage stabilisation, many of which are fast enough to protect some equipment against dips. Electro-mechanical, electromagnetic and electronic methods are described. These techniques, all of which require a significant retained voltage, are still relevant, providing a good degree of protection without the negative side effects, such as harmonic distortion, that may accompany other solutions.
Read full story
By Bryony Samuel / Published on Wed, 2008-12-03 10:33
This Application Note discusses the causes and effects of voltage dips. Some dips are caused within the installation by, for example, starting of heavy motors or other loads, and these are usually easy to identify and resolve. Most dips originate in the supply network as the result of faults and these can neither be predicted nor controlled by the user. The causes and characteristics of network dips are discussed.
Read full story
By Hans De Keulenaer / Published on Tue, 2008-09-09 10:07
The problem of voltage sags and Swells and its severe impact on sensitive loads is well known. To solve this problem, custom power devices are used. One of those devices is the Dynamic Voltage Restorer (DVR), which is the most efficient and effective modern custom power device used in power distribution networks. Its appeal includes lower cost, smaller size, and its fast dynamic response to the disturbance. This paper describes DVR principles and voltage restoration methods at the point of common coupling (PCC ).
Read full story
By Hans De Keulenaer / Published on Mon, 2008-09-08 07:46
Digital simulation is a powerful mean to predict the voltage dip performance of a power network. Voltage dip characteristics can be accurately reproduced using present simulation tools and a stochastic prediction procedure that could incorporate the random nature of the voltage dip causes and the behaviour of sensitive equipment during this type of events.
Read full story
By Hans De Keulenaer / Published on Fri, 2008-09-05 11:12
This paper introduces an alternative method for voltage sag source location based on voltage information only. The source is located considering the sag magnitude at the primary and secondary side of a transformer. A comprehensive review of previously proposed methods based on voltage and current measurements is presented. The performance of the proposed method is compared with the previous ones using PSCAD /EM TDC on a model of a regional network including transmission and sub-transmission levels.
Read full story
By Hans De Keulenaer / Published on Thu, 2008-09-04 09:01
Math Bollen, Mark Stephens, Kurt Stockman, Bill Brumsickle, Saša Djokiæ, Alex McEachern, José Romero Gordon
This paper presents the status of the work, by April 2008, in C4.110,
a joint working group by CIGRE, CIRED and UIE. Contributions of the
working group are: a summary of voltage dip characteristics; a
methodology to assess the performance of a complete installation and;
recommendations for testing and immunity of equipment.
Read full story
By Hans De Keulenaer / Published on Thu, 2008-08-28 14:23
By Daniel Kottick
The Israel Electric corp. deployed a nationwide Power Quality Monitoring System (PQMS). The PQMS monitors the quality of supply of all of its high voltage costumers, as well as a sample of its medium voltage customers. The PQMS monitors both the voltages and the currents. The PQMS has been operational since October 2005. The paper presents preliminary measurement results obtained from the PQMS.
Read full story
By Hans De Keulenaer / Published on Fri, 2008-07-25 17:04
By Alex McEachern
A free Windows® program for teaching power quality concepts is presented. The program uses interactive graphs and controls. Concepts include fundamental and reactive power, sequence vectors, voltage dip effects on single-phase and threephase rectifier loads, flicker, harmonic concepts, harmonic power flow, harmonic sequencing, and distortion and source impedance. The program operates in English, Spanish, French, German, Italian, Portuguese, Romanian, Swedish, and Polish, with Japanese and Malaysian expected soon.
Read full story
By Hans De Keulenaer / Published on Fri, 2008-06-27 10:24
By J Arbi et al
In this paper, the authors study a variable speed wind generation system based on Doubly Fed Induction Generator (DFIG) in case of large balanced voltage dip and analyzed a remedial solution that allows for the turbine to stay connected and helps grid recovery through reactive power injection, by supplying the grid with reactive power during faults. Simulation results show the effectiveness of the solution in different operating points of the four working regions of the power-speed turbine characteristic.
Read full story
By Hans De Keulenaer / Published on Tue, 2008-04-22 14:51
This mini site presents the results of European PQ Survey with a focus on power quality critical sectors.
The main brochure explains why the industrial sectors interviewed lose annually upwards of €150 billion as a direct result of their electrical power installations not being sufficiently reliable and resilient for today’s and future operating demands.
Read full story
