The Quality of Electric Energy
Since the emergence of the electricity and the technological advances, the world economy has become more dependent on electric energy, which essential for the development of the major sectors. The truth is that, despite being widely used, it is still difficult to store electricity efficiently, as well as control its quality. Thus becomes critical to measure the quality of electric energy in order to use it in the most correct and efficient.
Problems and Costs
One of the bigger problems regarding the quality of the electric energy becomes from the fact that certain equipment to function incorrectly or being ill-scaled, which consequently can take to fails, interruption of the production process, and can origin high costs due to production breaks. Some disturbances do not lead to disruption of procedures, but it can lead to other direct costs, such as the reduction of the decline in yields and the service life of the equipment. The costs that come from the quality of electric energy can be evaluated in three types:
Direct Costs – these kinds of costs are associated to perturbances of the quality of electric energy, including equipment damage, loss of production and raw material, labour costs during the period not productive (maintenance actions) and the remaining costs regarding the restarting of the process.
Indirect Costs – associated with the failure of delivery times, leading to a degradation of the image.
Non-material Costs – associated with nuisance and not financial costs. For example, the privation of informatics systems by the interruption of electrical power supply, which generally does not imply financial costs, but can cause significant inconvenience.
These problems and its associated costs can be reduced by the identification of the causes and the adoption of corrective measures. One of the ways to detect and diagnose problems is by using monitoring tools for the energy quality.
This equipment can measure and register voltages, currents and powers in various channels during periods of times. Based on the collected information it is possible to generate alarms and produce reports of various types, through the selection of different applications. The quality of electric energy monitoring can be done all the time that anomalies occur, or it can be done continuously.
Figure 1 – Current Transformer
Audits the quality of electric energy
An audit must have as a goal to identify the problems of the quality of electric energy and its origin. After characterising the problems and the origin it will be easier to identify possible solutions.
Identification of the situation – phase of collecting all the information regarding the verified problems (the type of affected equipment; problems verified on the equipment; the beginning of problems; frequency of the problems; recently alterations made to the installations).
Data Collection – phase of the methodology definition to follow to identify the problem. The first step goes through a visual inspection of the electrical installation. In this procedure must be verified if there are no problems in the links for drivers if there are no conductors degraded if the lands are properly connected and if the electrical system components (drivers, guards, transformers) are adequate to the function. Not being possible to identify the problem through visual inspection, should be monitoring the unit supply affected and how this is used. For the data collection can be used various types of equipment available on the market. One fundamental criterion for the equipment choice must be the equipment sensibility affected by the problems of the quality of electric energy.
Data collection analysis – phase of problems identification and evaluation of the respective causes, based on the data collected.
Suggested solution – phase of consideration of all economically viable solutions, with its calculation of investment and associated turnaround time, so the facilities choose one of the solutions.
Since the beginning, TecnoVeritas dedicated to the provision of inspection services, metrology and quality analysis of electrical current. The measurement of power quality is part of the wide range of inspection and Metrology Services. Whatever the problem of your installation, we are available to help you solve.