Análisis térmico de los elementos de sujeción del núcleo de un reactor trifásico

In this thesis work the temperature distribution in the frame bolts of a 5 MVA, 115 kV, 60 Hz, three-phase five-limbs shunt reactor is obtained utilizing the finite element method (FEM) and the commercial ANSYS Maxwell software. This because the reactor actually failed while it was running, the failure occurred progressively as the screw insulation was damaged and caused an unwanted temperature rise. A time-harmonic analysis is performed to compute the magnetic field distribution in the reactor and the power losses in the frame bolts. A three-dimensional (3-D) shunt reactor model is utilized, and Maxwell’s equations are solved utilizing scalar and vectorial magnetic potentials. The 3-D electromagnetic shunt reactor model is validated by comparing the value of inductance measured in the laboratory with the value of inductance computed in the 3-D FE simulation. In addition, the core losses computed in the FE simulation are compared with the core losses measured in the laboratory. This thesis work is important for transformer manufacturers which requires an adequate shunt reactor model to analyze it under different operation conditions and to optimize the actual design.

Influence of voltage fluctuations on core vibration of a UHV shunt reactor

A new core vibration calculation method of UHV shunt reactors is proposed to deal with the problem that vibration parameters of the core of an ultra-high voltage (UHV) shunt reactor cannot be measured on site. A series of tests have validated that the method can calculate the vibration parameters of a UHV shunt reactor core with different voltage ratios. The method is adopted to study the influence of nodal voltage fluctuations of the UHV AC tie line on the core vibration characteristics of a UHV shunt reactor under normal and abnormal operating conditions. The conclusion is drawn as follows: in the three operating states assessed herein, no matter whether the power grid is in a normal state or not, the core of the UHV shunt reactor will not reach magnetic saturation, and the vibration parameters of the reactor always maintain a linear relationship with the operating voltage. The changes of power grid operation parameters are introduced to the research into reactor vibration, which is conducive to a more comprehensive understanding of the actual operating state of a UHV shunt reactor. It can also provide help for the design and operation of UHV shunt reactors.