Single-phase 50-kW 16.7-Hz PI-controlled four-quadrant line-side converter lab model fed by rotary converter

Four-quadrant line-side converters supplying PWM-inverter-fed induction machines are a standard application in railway traction vehicles. In scope of an extensive project aiming at an advanced overall control scheme for traction vehicles taking amongst others grid interaction and stability into account, the steady-state and transient operation of a single-phase 50-kW, 16.7-Hz four-quadrant line-side converter are analysed in detail. This topology is hereby fed by a slip-ring induction generator (IG) with DC excitation, operating as railway-grid rotary-converter representation. In this paper the structure of the 50-kW test bench representing a railway grid and a traction vehicle and the used PC-based real-time control hardware are introduced. Despite the highly disturbed rotary converter output voltage measurement results verifying excellent operation are given for the line-side converter, whose PI-control scheme is described in detail. Hereby two different loads are used: resistor and motor inverter.