Technologies        
  Hauptmenu
 
    Introduction
    Database
    -  Technologies
  -  Projects
    Calendar
    Discussions
    Contact & Links
    Imprint & Disclaimer
    Sitemap
 
 


     
 
Content
 
back to list go back to technology list      previous previous technology  next technology  next

   Loss reduction by optimised power intake  evaluated  
Some electric vehicles are equipped with a control tool regulating the power intake according to distance from substation. The system aims at avoiding negative effects on power electronics through high currents. As a side effect catenary losses are reduced.
Technology field: Optimisation of traction technologies
close main section General information
  close sub-section Description
    Power losses in catenary are proportional to I2, the square of catenary current. From an energy efficiency perspective, it is therefore desirable to have low currents. On the other hand, traction power is P = U ? I, meaning that the current needed depends on the voltage. Since catenary voltage U drops with distance from substation, the current I would accordingly increase, leading to higher losses. This may be avoided by reducing power intake of traction unit according to distance from substation. Such a system is realised on most new electric vehicles. An on-board sensor measures catenary voltage and regulates the maximum power intake in order to avoid high currents. As a consequence, acceleration performance on part of the network is slightly reduced and therefore running time is slightly increased. Most new electric stock are equipped with such a control tool. A retrofit of old vehicles is not feasible.
close main section General criteria
  close sub-section Status of development: in use
    Technology is a standard on new electric stock.
  Time horizon for broad application: now
    (no details available)
  Expected technological development: (no data)
    (no details available)
    Motivation:
   

Current limitation

High currents are a problem for on-board power electronics.

Reduction of traction losses is just a side effect.

  Benefits (other than environmental): medium
   

Current limitation

Excessively high currents have a negative effect on traction power electronics.

  Barriers: medium
    Retrofit of old vehicles is not feasible.
    Success factors:
    (no details available)
  Applicability for railway segments: high
    Type of traction:  electric - DC, electric - AC
    Type of transportation:  passenger - main lines, passenger - high speed, passenger - regional lines, passenger - suburban lines, freight
    (no details available)
    Grade of diffusion into railway markets:
  Diffusion into relevant segment of fleet: (no data)
  Share of newly purchased stock: (no data)
    (no details available)
  Market potential (railways): high
    (no details available)
    Example:
    (no details available)
close main section Environmental criteria
  close sub-section Impacts on energy efficiency:
  Energy efficiency potential for single vehicle: < 2%
  Energy efficiency potential throughout fleet: < 1%
    No data on saving effect are available. Given that catenary losses account for about 10% of the energy drawn from substations, and the fact that the control tool regulates the current only within a small range, the overall saving potential will be less than 2%.
  Other environmental impacts: neutral
    (no details available)
close main section Economic criteria
  close sub-section Vehicle - fix costs: low
    As part of new vehicles, the control tool does virtually not increase the vehicle price.
  Vehicle - running costs: minor reduction
    (no details available)
  Infrastructure - fix costs: none
    (no details available)
  Infrastructure - running costs: unchanged
    (no details available)
  Scale effects: none
    Being a standard in new electric stock already, additional scale effects are not to be expected.
  Amortisation: < 1 year
    (no details available)
no data available Application outside railway sector (this technology is railway specific)
close main section Overall rating
  close sub-section Overall potential: interesting
  Time horizon: short-term
    A control mechanism for power intake has become a standard in new electric stock. The saving potential is moderate. Since a retrofit of old stock is not possible, the diffusion of the technology does not depend on any additional efforts on the part of railways.
References / Links:
Attachments:
Related projects:
Contact persons:
 date created: 2002-10-09
 
 
© UIC - International Union of Railways 2003
 
Aktionmenu
 
 Your contribution
   add technology
 Views of this page
   show overview
   show evaluation
   show details
 Print options
   print data sheet
   print screen
 Help
   Evaluation briefing
   Technology list
    French - German