Power Quality in Electrified Transportation Systems

"Power Quality in Electrified Transportation Systems" has covered interesting horizontal topics over diversified transportation technologies, ranging from railways to electric vehicles and ships. Although the attention is chiefly focused on typical railway issues such as harmonics, resonances and reactive power flow compensation, the integration of electric vehicles plays a significant role. The book is completed by some additional significant contributions, focusing on the interpretation of Power Quality phenomena propagation in railways using the fundamentals of electromagnetic theory and on electric ships in the light of the latest standardization efforts

Topologies and operation modes of rail power conditioners in AC traction grids: review and comprehensive comparison

Electric locomotives in AC traction power systems represent a huge single-phase non-linear load and, detrimentally, affect the power quality and the efficiency of the three-phase power grid. Nevertheless, along the last decades, power electronics are being used to mitigate power quality problems in the three-phase power grid. In particular, Rail Power Conditioner (RPC) helps to increase the loading capacity of traction substations and improve the power quality of three-phase power grids. As the main characteristics, an RPC can supply reactive power, suppress current harmonics and overcome currents imbalance of the three-phase power grid. On the other hand, the traction substations may be constituted by different types of power transformers. For instance, single-phase power transformers and open-delta (V/V) power transformers are widely used, while Scott power transformers are less frequently used, since they are more complex and expensive. In this framework, this work presents a review study of RPC topologies, including their operation modes, and a comprehensive comparison between the characteristics of the RPC topologies when using different types of AC traction substations and power transformers. This helps to ensure the correct selection of the RPC topology for a specific application, according to the main structure of the traction substation. Consequently, and based on the established review, it is possible to sort and allocate each RPC topology for limited or wider applications.This work was supported by the Portuguese Foundation of Science and Technology (FCT) (in Portuguese, Fundação para a Ciência e Tecnologia, within the R&D Units Project Scope: UIDB/00319/2020). The first author Mohamed Tanta is supported by FCT Ph.D. grant with a reference PD/BD/127815/2016

A compensation system for cophase high-speed electric railways by reactive power generation of SHC&SAC

In this paper, a system with series hybrid converter and shunt active converter (SHC&SAC) for compensation in cophase high-speed electric railways is proposed. Unlike the general power flow conditioners, the dc-links of the two converters are separated, and therefore, the two converters can operate independently. Just by taking the advantage of the reactive power generation ability and novel connection of SHC&SAC, the grid-side power factor can be improved and negative-sequence current can be suppressed, especially on the cases of high-speed trains. Besides, because of the capacitor in SHC, the active capacity of SHC is significantly lower than that of SAC. To obtain a good current tracking performance, the passive control method, which is based on the dissipation characteristic of resistor, is adopted for controlling converters. And finally, the effectiveness of the system is verified by simulation and experimental results