Railway modelling for power quality analysis

Abstract

Power quality is increasingly important in the consideration of railway systems. Poor power quality affects the performance of trains and introduces problems for local distribution networks.This paper looks at improving modelling techniques to assess the power quality of a railway system. Modelling techniques used to simulate electrified railways are adapted to simulate power quality aspects with improved computational efficiency. The model developed is used to assess the voltage regulation and harmonic distortion of a rail system, and harmonic distortion on the local distribution network.

Impact Assessment of Energy Storage Systems Supporting DC Railways on AC Power Grids

“…1. The TPS, like most of the conventional substations, is not reversible and can be modelled as an ideal voltage source VDC in series with a resistor RTPS and an ideal diode [20], [29]. Contrariwise, within this work LRVs are modeled as ideal current sources: ILRV value is computed as the ratio of the LRV power PLRV, and the line voltage at the LRV position, VLRV, that changes along the track.…”

“…Among them, SC and flywheels-based ESSs are the most attractive ones due to their high specific power, the large number of charging and discharging cycles, and the expected future advance of these technologies [15]. Several papers have been produced on the implementation of wayside ESSs [12], [15]- [20]. In particular, an SC-based substation for voltage drops compensation in light rail networks is investigated in [12] while [15] has proposed a control strategy for wayside SCbased systems implementing the real-time management of voltage levels at catenary connection points.…”

“…However, railway DC feeder systems produce harmonic distortion and voltage unbalance on the local distribution AC network [20]. The harmonic distortion is caused by nonlinear currents drawn by the railway DC system through the rectifying substations [20]- [21].…”

“…However, railway DC feeder systems produce harmonic distortion and voltage unbalance on the local distribution AC network [20]. The harmonic distortion is caused by nonlinear currents drawn by the railway DC system through the rectifying substations [20]- [21]. In detail, voltage unbalance is present in AC systems when the DC feeder system draws large currents from a single phase of the AC supply network [22]- [23].…”

Steady-state analysis of power distribution system with dynamic charging electric vehicles

“…Interestingly, a relevant research area, however, is railway electrification systems with a focus on electric locomotives. Most importantly, [10][11][12][13][14][15] carried out power flow analysis of electrified tracks, wherein several new power flow algorithms are introduced, based on which power supply capacity of traction power supply systems and voltage distribution in transmission systems can be analyzed. Another important research direction on trains, tramways, and buses is to apply regenerative braking energy and leverage the topology of the power supply system to enhance the system's e ciency and economic operation [1,16].…”