The increasingly widespread use of load control systems through components of power electronics causes the appearance of harmonic currents circulating in the system.
In industrial contexts with large power process plants fed by direct current, the phenomenon assumes relevant characteristics that cannot be ignored due to the effect produced both on the plants and on other electrical loads.
The harmonics present in the system cause a general worsening of the Power Quality and are at the origin of numerous electrical disturbances such as the overload of the distribution network, the overload in the neutral conductor, the vibrations of the transformer core, the anomalous stresses with the consequent dielectric degradation of the power factor correction capacitors and, moreover, various malfunctions of the most sensitive electrical consumers.
To solve the power quality problems of a particular industrial site subject to considerable fluctuations in grid voltage with an important presence of harmonic currents, IREM has developed a special Sterostab Voltage Stabilizer, with a nominal output of 500 kVA, coupled to a passive filter capable to reduce the harmonic content THDi% from an initial value of more than 95% to a maximum value of 5%.
Furthermore, to meet the requirements imposed by a work environment made particularly critical by the presence of conductive powders, the equipment was made with a high degree of protection: IP54.
IREM Sterostab Voltage Stabiliser optimally integrates with the passive filter since it cancels both the increase of the no-load line voltage and the reduction of the full load line voltage typical of this particular type of filters. These characteristic secondary effects of the L-C filters are completely overcome by the action of the Voltage Stabilizer which dynamically compensates the behavior of the filter releasing it from the applied load factor.
The main advantages, in terms of Power Quality, deriving from the use of a Voltage Stabilizer equipped with THDi% Passive Filter are:
- the stabilization of the mains voltage
- the reduction of the harmonic content
- the increase of the power factor
- the mitigation of flicker occurrence.