Improving the energy performance of alternating-current electric vehicles

Abstract

Russian Railways has taken an active position on the implementation of programs aimed at energy saving. The strategic priority of these programs is the development and introduction of new types of energy-efficient rolling stock, as well as modernization of existing and procurement of new locomotives with improved energy characteristics. After a long period of stagnation in the transport-engineering industry, railway- equipment manufacturers have started to use advanced resource-saving technologies. However, ac electric locomotives with rectifier–inverter converters and electrical locomotives with diode rectifiers equipped with a step-voltage regulator for the traction transformer are still used by Russian Railways. Despite the fact that starting and speed control of ac electric locomotives are carried out without losses in starting resistances, the increased consumption of reactive power and distortion of the form of current consumed from catenary system are a common problem for electric locomotives of this generation. The main methods and circuit design of reactive power regulators and selectors of current high harmonics and voltage in ac electric rolling stock, as well as the principle of operation and structure of the active and hybrid filters and power correctors, are considered in this article. Examples of various technical solutions providing active filtration of higher harmonics are given.