超导超高压同步调相机多工况下定子电磁力计算及强度分析

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

超导调相机采用电缆绕组非磁性齿的高压定子新结构(简称超导超高压调相机),可实现调相机与电网的直连。针对超导超高压调相机定子采用非磁性齿结构,导致齿部磁阻增加,槽漏磁增大,出现定子齿壁两侧受力不均以及绕组切向洛伦兹力增大的问题,构建了超导超高压调相机无升压变压器与电网直连的场-路耦合数学模型,结合麦克斯韦应力法和洛伦兹力原理,计算了进相与迟相运行,短时深度进相与迟相运行4种运行工况下定子齿壁所受电磁力,并给出齿壁两侧电磁力随时间以及空间的变化规律。将计算得到的电磁力作为载荷,对不同运行工况下定子齿的强度进行计算,得到了定子齿形变大小和应力分布规律。结果表明超导超高压同步调相机在多种工况下运行时,非磁性定子齿不会发生疲劳断裂现象。该研究为超导调相机采用非磁性定子齿及超高压绕组结构提供理论依据。

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.