TRACTION POWER / ELECTRIFICATION SYSTEM SIMULATION
Hi-SimuX provides detailed analyses needed to generate the most cost-effective designs, while ensuring operability under normal and contingency conditions. Outputs may vary depending on the scope of the project. Some of the main outputs supporting the traction power design process include:
- Instantaneous and RMS current demand from Substations and each feeder cable. RMS values can be given for various user-selected time windows.
- Train voltage levels,
- Running rail voltage rise (“touch potential”) with respect to ground and stray currents
- Energy consumption, regenerative energy usage rate etc.
Location-Rail Voltage graph on a metro line fed by 1500 VDC
The long-running traction system may require renovation / improvement, but what will be the most cost-effective investment plan? Hi-SimuX modeling capabilities can test existing traction system and assess the adequacy of it in case of addition of new stations to the line or introducing new trains on the line or decreasing the operational headway. If needed, necessary solution can be developed based on the simulation results.
RMS Traction Power total demand from the MV circuit during a day for 19 hours operation
Hi- SimuX can quickly analyze the effect of additions or changes to the traction system, for example adding of a substation or a feeder cable, optimizing the output voltage level of the substation or changing the return current system.
For a safe operation of traction power system, it is extremely important to define correctly the protection relay parameters of circuit breakers.
Hi-SimuX can calculate close and remote short-circuit currents by analyzing the steady-state of short-circuit conditions on the DC side. The software can automatically generate tables that will assist in choosing circuit breaker settings by evaluating current and power values in all scenarios considered.
Short circuit current diagram along a line
Our simulation capability includes running multiple train type simultaneously with traction power simulation.
HEADWAY ANALYSIS AND OPERATION SIMULATION
We can analyse the best solutions to improve reliability of existing systems and determining the capital investment needed to support growth on the existing network and accommodating network expansion.
Our capabilities in rail operations analysis include feasibility studies, service/operating plan development, trip time predictions, network simulation/capacity analysis, fleet requirements analyses, cost-benefit studies, energy savings (“green”) studies, alternatives analyses, and conceptual design development. We use Hi-SimuX simulation suite which offers unique capabilities in integrated traction power/operations modelling, dispatch automation and signaling system analysis.
When scheduled rail operations are approaching (or, sometimes, exceeding) the practical capacity of the line at maximum scheduled speed, network operations simulation is a valuable tool to assess the reliability of an existing or proposed operation. Hi-SimuX support this type of analysis, which can be performed under both “deterministic” (no variability in performance of equipment or behavior of system) and “stochastic” (randomization that produces differences in each simulation run despite identical inputs) conditions.
HI-SIM’s simulation tool can carry out detailed single train type simulations, multiple train rail network simulations for operational evaluation as well as traction power simulation. We can perform these simulations not only for basic train performance evaluation, but also for the analysis of operational requirements by considering the traction power system. As transit agencies and rail networks with electric train operations strive to reduce consumption and peak demand, we can model the best energy-saving strategies. Our simulations can include coasting, reduced tractive effort, voltage dependent current limits, deployment of regenerative braking – all of which can make rail mode greener.
When designing a new rail system or modifying existing lines, the train performance can be realistically determined with the help of simulation. Simulation helps us to calculate the achievable train headways under normal and contingency scenarios, taking all the conditions and constraints of the lines (distances between stations, positions of switches, speed limits, tunnel zones, etc.).
Our capabilities in operation simulation include feasibility studies, service/operation plan development, trip time predictions, network simulation/capacity analysis, fleet requirements analysis, cost-benefit studies, energy saving (“green”) speed profiles determination, evaluation of different alignment and/or train alternatives, and conceptual design development. We use a simulation tool, Hi-SimuX, which offers unique capabilities in integrated train performance/operation, traction power system, and signaling system analysis.
When scheduled rail operations are approaching (or, sometimes, exceeding) the practical capacity of the line at maximum scheduled speed, network operations simulation is a valuable tool to assess the reliability of an existing or proposed operation. Hi-SimuX supports this type of analysis, which can be performed under both “deterministic” (no variability in performance of equipment or behavior of system) and “stochastic” (randomization that produces differences in each simulation run despite identical inputs) conditions.
Simulations can be carried out for a single train as well as for multi-track and multi-train situations. These simulations can be done only for basic train performance or in combination with the traction power systems.
When performing these simulations, the safe braking algorithms specified in the standards for train control are taken into consideration, and the achievable un-interfered headway and interfered headway can be determined.
With train performance simulations, it is possible to determine the trip time (and average speed) between each station, total journey times and the number of trains that will be needed for the operation plan.
In an operation simulation, generally the following operating conditions can be tested.
- Investigation of Normal Operating Status
- Determination of the Shortest Headway at Turnbacks
- Investigation of Train Injection and Withdrawal for Wind-up and Wind-down
ROLLING STOCK OPTIMIZATION
When a new vehicle is to be introduced to an existing system, we can determine the effects of the vehicle(s) on the system. We examine in detail the speed – time curves, energy consumption, the effects on traction power and catenary systems.
Similarly, we can help the authorities on train procurement tenders to determine vehicle’s life cycle costs by realistically calculating the energy consumption costs of different vehicles on the same line.
Our services include finding and confirming the most suitable alignment design for operational purposes. By analyzing trip times and capacity (Headway) of different route designs, we help railways and transportation authorities to develop the most cost effective design.
Hi-SimuX software can be used for single train as well as multi-line or/and multi-train situations. We can perform these simulations not only for basic train performance evaluation, but also for the analysis of operational requirements considering the traction power system.
Hi-SimuX’s train library and flexibility in creating and editing new vehicle models support these analyses.
- Can the train meet the planned trip time?
- What will be the energy consumption under multi-train operation?
- What percentage of the regenerated energy would be burnt on the brake resistors?
- What happens if an additional vehicle is added to train?
- What would be effects of shutting down one or more diesel motors in a DMU?
- Would electrification system allow using a second locomotive?
In train procurements, both the administration and vehicle manufacturers can be supported in terms of optimum dimensioning. At the below given table, the effects of different vehicle characteristics on travel time, main traction power system parameters and energy consumption are given. The table shows the importance of optimization of the vehicle traction system package.