In the field of DC transport systems more than anywhere else, to provide an adapted, efficient and safe product has become a key factor. With millions of every day users, installations must be at the head of reliability and security. Due to its long experience in the DC traction domain, Sécheron has developed an excellent know-how for the DC system design. Today, Sécheron can offer a large panel of services for DC traction network design and simulation in order to ensure the correct design and protection of the system. It is indeed essential to understand all the subsystems of a traction network such as AC network, DC power supply substation, DC network and vehicles, and our engineering team does this successfully!
Available to clients looking to establish, or to improve, existing equipment or services, Sécheron applies its extensive experience to a variety of situations. Our offer includes a wide range of services from dynamic network simulation to harmonics calculation and measurement, through various calculations and tests about transformer-rectifiers sets or short-circuits. We offer consulting expertise and are willing to answer any questions you may have about DC traction network design and calculation.
Dynamic DC network simulation
For DC Railway applications, a good knowledge of the whole system behaviour is highly important. To take into account the huge number of parameters and the complexity of the interaction between all parts of the system, Sécheron has developed DC network simulation software.
Studies we provide can, among other things, answer the following questions:
- Where to implement the substations and how many?
- What power and which overload capability are required for the rectifier set?
- What rating shall be provided at each level of the feeding system (DC circuit breakers, disconnecting switch, cables etc)?
- What will the voltage drop along the line be?
- What happens if one substation fails?
- What is the efficiency of the system and how to increase it?
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The picture shows the result of a simulation of traffic in a 1500VDC LRT network including 9 substations.
This case shows an alternative where substation number 7 is out of service.
The diagram allows the reading of minimum, maximum and rms current values at each DC output feeder in the entire network and these results serve as guide for the most suitable setting of high speed circuit breakers. |
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Short-circuit calculation and testing
Sécheron, as a supplier of DC high-speed circuit breakers, has acquired a strong knowledge and understanding in the domain of short circuits. Theoritical knowledge and calculations complemented by on-site or laboratory testing (IPH Berlin or CESI Milano) satisfy the demands, in terms of protection solutions, of major transit authorities worldwide.
We are able to provide our partner with different services such as:
- On-site short circuit measuring in order to check the protection and appropriate adjustment.
- Short circuit calculation in order to select the components in the electric distribution chain.
- A complete study for the design of protection (line fault DDL, Imax, thermal etc.).
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Dynamic simulation results example : speed and acceleration of a vehicle running along the line
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| Field short-circuit test - measurement of the voltage and the current during a short-circuit test |
Harmonics calculation and measurement
Nowadays, more and more regulations concern the harmonic content generated by the power converters in AC or DC networks.
We are able to deliver several services in this domain:
- AC and DC harmonics calculation
- On-site measurement of harmonics in the network.
- Improvement solutions like harmonic filters, 12 or 24 pulse operation.
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On-site measurement of AC harmonics : AC current and FFT of a 6 pulse rectifier of 1.2MW - 600V
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Design and protection coordination for the transformer-rectifier set
Sécheron has a long experience in building transformer-rectifier sets, this has led us to develop particular software for the design of the transformer and rectifier in the most accurate and optimal way.
We are able to provide answers to any particular questions regarding transformer-rectifier sets and their operation within the traction system.
We are experienced in combined tests, according to the EN50328 or IEC60146 standards, including, for instance, short circuit, warm up and off-load operating tests.
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Digital simulation on a transformer-rectifier set
For more information, please e-mail substations@secheron.com or sign up to the Download Center by clicking here.
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