Modelling of rotary converter in electrical railway traction power-systems for stability analysis

The central European 16.7-Hz railway grid is fed — beside by own power sources — by rotary and static converters. In context of recent low-frequency stability problems in the Scandinavia region, primary the interaction of four-quadrant line-side traction-converter control and surrounding rotary converters is a major concern. Therefore, adequate models for time-domain simulation are necessary. In this paper, a set of differential equations — representing even the transient behaviour of a rotary converter — are derived. Based on this resulting differential equations, simulations studies of the transient behaviour are presented. Furthermore, the behaviour of rotary converters with and without a damper-winding system on the three-phase side is analysed. Additionally, the three-phase machine can be simulation with anisotropic characteristics.