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Examination and Analysis of the Energy Efficiency of Pesa Swing 122NaSF and Pesa Swing 122NaSF2 Tram Types

Lubomir Sekulov
Todor Kableshkov University of Transport Sofia, 158 Geo Milev Str. THE REPUBLIC OF BULGARIA

Georgi Pavlov
Todor Kableshkov University of Transport Sofia, 158 Geo Milev Str. THE REPUBLIC OF BULGARIA

Abstract

The paper focuses exclusively on Pesa Swing 122NaSF2 tram types. Two models of PESA SWING trams operate in the city of Sofia, with the first type having been brought into service since 2013, and the second one - since 2016. On the whole, the total number of trams amounts to 24. Technically speaking, they provide public transportation services along two main routes in Sofia, tram lines 7 and 18. The lines differ in their route lengths, stop spacing, surface slopes and vehicle stoppages and downtime, as determined by the distinctive features of the urban infrastructure. Presented in the paper are some concrete details as to the parameters of the two tram routes, obtained as a result of an accomplished experimental research study.
The surveyed tramcars use alternating current asynchronous motors, composed of four individual traction motors within the range of 105 kW. The traction motors employ two double traction inverters 2xFT105-600, one for each bogie construction. The trams under consideration run at a maximum speed of 70 km/h, have the capability to overcome an inclined surface, the maximum gradient of which is 60 ‰, with a track gauge of 1009 mm and permissible kerb (without passengers) weight of 20 000kg.
The air conditioning system in the lounge area consists of two pieces of HVAC 6406 equipment, each of which has a rated capacity of up to 24 kW and 17 1000W heaters. As for the tram driver’s cabin, there is a separate HVAC 3405 3-6kW unit and a 5400W heater. The power for their own consumption is provided by two PSM36-TI static converters with 3х400V/25kW and 24VDC/10kW output voltage range.
The experimental studies were performed under varied operating conditions and across all main modes of operation (traction and electric braking) of the two tram models hereto discussed. Considered carefully are also the parameters indicative of their energy efficiency – specific and relative energy consumption in the mode of traction, recuperative braking mode efficiency, as well as the power consumption for their own needs, heating and air conditioning. The values obtained from the performance measurements and their subsequent processing were closely examined to put forward a set of specific recommendations with regard to some practical opportunities for improved energy efficiency of the surveyed passenger vehicles.