Passive Vibration Control in Electric Reactor Using Viscoelastic Dynamic Absorber

Abstract

The efficiency of the current electrical transmission system in Brazil, as well as the management of energy maneuvers, depends directly on the quality of the services offered at each substation. Within this context, it is possible to find three-phase electrical reactors in substations. These devices have specific functions in the operation and maintenance of the functionality of these facilities, being equipment applied in the control of reactive, short-circuit currents and switching surges in electrical energy transmission systems. However, some reactors when in operation can present high amplitudes of structural vibration. The existence of this type of operational problem can cause interruptions in the transmission of electrical energy. The application of tools used in the mitigation of vibration in reactors can avoid structural and operational damage that often results in the mandatory stop of the equipment. In order to reduce localized vibrations, it is proposed to apply dynamic absorbers fixed to the external structure of a reactor. Once the regions with the highest vibration amplitude levels in the reactor are known, the absorbers are dimensioned in terms of quantity, position, and defining parameters (mass, stiffness, and damping), tuned to the excitation frequency, of an electromagnetic nature, in order to absorb part of the vibratory energy. Viscoelastic materials are used in dynamic absorbers (with dynamic properties dependent both on temperature and on the operating frequency), because these materials increase the field of action of the absorbers, adapting them to the high modal density, verified in some regions of the sheet metal. reactor metal. In this sense, it will also be presented in this work the calculation of dynamic absorbers with viscoelastic damping applied in some regions with high levels of vibratory energy in the reactor, as well as the result of the application of these absorbers observed via the finite element model. A reduction in the vibration amplitude in the vicinity of the application point of these absorbers was verified.