Stator electromagnetic force calculation and strength analysis of superconducting ultra high voltage synchronous condenser under multi-operating conditions

Superconducting condenser adopts a new structure of high voltage stator with non-magnetic teeth of cable windings (referred to as superconducting ultra high voltage condenser), which can realize the direct connection between the condenser and the power grid. For the superconducting ultra high voltage condenser, the stator adopts a non-magnetic teeth structure, which leads to the increase of teeth reluctance, the increase of slot leakage, the uneven force on both sides of the stator teeth wall, and the tangential Lorentz force of the winding of the condenser is increased. The field-circuit coupled mathematical model of superconducting ultra high voltage condenser without step up transformer directly connected to power grid was established. Based on Maxwell stress method and Lorentz force principle, the electromagnetic force on stator teeth wall under four operating conditions of leading and lagging power factor operating and short time deep leading and lagging power factor operating was calculated, and the variation of electromagnetic force on both sides of the teeth wall with time and space were given. Using the calculated electromagnetic force as the load, the strength of stator teeth under different operating conditions was calculated, and the deformation size and stress distribution of the stator teeth were obtained. The results show that the non-magnetic stator teeth will not break when the superconducting ultra high voltage synchronous condenser operates under various operating conditions. The research provides a theoretical basis for using non-magnetic stator teeth and ultra high voltage winding structure for superconducting condenser. © 2024 Editorial Department of Electric Machines and Control. All rights reserved.