Abstract:

This paper presents a didactic procedure and the specific equipment, dedicated for training students or specialists in the field of low voltage power quality and Electro Magnetic Compatibility (EMC). Today electronic equipment includes many devices having very fast and frequent load variations, used due to some obvious benefits like energy efficiency, flexibility, low volume, low costs and even increased reliability. Despite all advantages, these devices are also producing some important power disturbances on electrical distribution lines, mostly harmonics or fast changes and fluctuations of the reactive power or of the supplying voltage. All power quality related aspects become mandatory today, for all electrical, power and electronical engineers worldwide. By consequence, permanent training and formation of all specialists acting in this area, according to the updated norms and regulations of this field, becomes a real necessity nowadays. Our training module and didactic procedure is related to a main component of power energy quality in electrical power systems: the harmonics/interharmonics pollution of a current wave passing throughout a normal nonlinear domestic load/consumer. First, we present some generalities about harmonics, followed by the description of a very simple and efficient didactic platform. It uses some simple pieces of equipment which are used by all electrical engineering laboratories worldwide, integrated in a compact educational system with real equipment. Inside the equipment, there are some electronic devices which normally produce EMC controlled and adjustable perturbations, connected to measuring devices. All trained students must evaluate the perturbations first, by dedicated methods (evaluating the THD - Total Harmonics Disturbance), in each situation. The method proposed for evaluating the THD is implemented on a software application which helps the student to understand the physical base of the computation and to fast all calculations. It could be also integrated in a virtual EMC laboratory, by setting the initial parameters which are now obtained by measurements. After identifying the equipment, they must propose adequate corrections by using EMC filters. All experimental results obtained are confirming the theoretical models applied for making this educational platform. Finally, there is a set of specific conclusions, related to this didactic procedure and equipment and there are also specifications for future perspectives of using this didactic platform, together with some results already obtained with our students.

Keywords:

didactic procedure, power quality, harmonics