Research on Three-Dimensional Stress Distribution of Reactor Core

Gapped iron-core reactors can obtain larger inductance, but they make larger vibration and noise than other kinds of reactors. On vibration dampers, many researchers kept their eyes on vibration isolation structures or vibration isolation materials. However, they did not compute reactor core vibration under fundamental frequency voltage or harmonic one. Because stress is the inherent reason of vibration and noise, this paper proposes a finite-element model for reactor core stress calculation based on the Maxwell stress theory. The model can handle reactor exciting currents, not only fundamental frequency but also superposition of fundamental frequency with different harmonics. Because core materials have different magnetic characteristics under different excitation conditions, this paper tested multigroup H-B curves to support the simulation. Then, the finite-element method is used to calculate the magnetic field and Maxwell stress distribution. Finally, the frequency spectrum of the stress is analyzed to provide a theory basis for further analysis of vibration and noise reduction in gapped iron-core reactors.