Metrology support for enhanced energy efficiency in DC transportation systems

This paper describes a new EU-co-funded project on metrology support for enhanced energy efficiency in DC transportation systems (e-TRENY). The project involves 5 national metrology institutes, 3 universities, 1 metro operator, and 1 consulting group. Research focuses on the following topics: i) new calibration facilities for DC transducers (up to 3 kV, 1 kA) under dynamic conditions, ii) accurate on-site losses of the converter group (power transformer – AC/DC bidirectional converter, DC/DC converter) operating in DC substations, iii) energy saving performance of transportation systems with non-conventional DC substations.

I. Introduction

The DC railway and metro systems supplied by unidirectional substations exhibit a notable energy inefficiency, primarily stemming from their incapacity to fully reclaim the energy generated during electric braking. Bidirectional substations and/or storage systems are expected to significantly improve energy efficiency, but IEC TC9, CENELEC SC9XC, and CENELEC TC14 raised concerns about the lack in this field of standard procedures for the determination of the actual performance of specific devices e.g. current measuring equipment, power transformers or converters and of efficiency of the overall system. In response to these concerns, the presented project [1] aims to tackle these issues by developing new methodologies for determining the electrical energy efficiency in DC transport systems.