Diseño de prototipo de fuente controlada de voltaje para motor trifásico, de rotor bobinado
2002
Instituto Tecnológico de Costa Rica. Escuela de Ingeniería en Electrónica.
INDUSTRIA NACIONAL DE CEMENTO S.A.
INCSA.
In the process of distribution of electric energy, the companies that take it upon to generate it and
distribute it should watch over for the better utilization of the same, giving each user the same quality
of the product and avoiding the maximum the waste and the losses. In order to achieve it, the
companies of generation and they of distribution apply regulations and fines to the big companies and
factories that they don't fulfill certain ranges in the utilization of the electricity. One of the parameters
to respect is the power factor (pf), the phase difference that is produced between the voltage vector
and the current vector. In the case of the factories, that in their majority relies on motors (inductive
element), a backwardness of the current is produced with concerning the voltage, producing loss in
the lines of transmission, for it should be corrected this problem.
With the utilization of semiconductors of capacity, it are succeeded in getting increase the
efficiency in the utilization of the resources already available, so much in the part of control like in the
own element managed by these. Like for example: the utilization of changer frequency for the starts
of motors, the utilization of rele of state solid. In this case in particular in the creation of a source of
voltage of direct current, designed with thyristors to have the characteristic that is controlled. It with
her get excited the rotor of a motor triphase, in order to have control on the value of the fp.
In this process of rectification for tall current should look after another of the parameters that are
regulated, like him is the generation of harmonics in the line, the which degenerate the quality of the
form of wave sinusoidal that gives the company. In order to avoid this problem it are proceeded to
carry out a design of two triphase rectifiers, formed by six thyristors (converter of 6 pulses), that is
connected in parallel to achieve current output, forming the called converter of 12 pulses, that
reduces the quantity of harmonics. In order to could interconnect the two converter of 6 pulses, it are
needed to make by means of a transformer of it couple and to can make the converter of twelve
pulses, the transformer that feeds at two of 6, it is of characteristic very special, with a winding
primary in connection wye and, two windings secundaries, one connected in wye and the other in
star, to achieve the good operation of the group. Also the part of control of shooting of the thyristors
should be adequate to this system of 12 pulses.
Proyecto de Graduación (Bachillerato en Ingeniería Electrónica) Instituto Tecnológico de Costa Rica, Escuela de Ingeniería Electrónica, 2002
Instituto Tecnológico de Costa Rica
Lidia Gómez
Cartago - 300m Este del Estadio Fello Meza. Apartado 159-7050.
2550-2263, 2550-2365