Motor control system makes trains more reliable
9 August 2006
Power Electronics / Power Management
Developed by Siemens rail technology experts in Erlangen, Germany, for controlling the drive motors of rail vehicles, the Sitrac system requires fewer sensors, a design factor that reduces downtime of the drive units and ultimately increases availability of trains. Equipped with very robust control technology, Sitrac recognises the motor's rotational speed without requiring a rotational speed sensor, and uses a current converter to adjust the torque and therefore also, the rail vehicle's traction.
Prior to Sitrac, control systems used direct measurement of the motor's rotational speed to control torque. These systems are equipped with a wheel speed sensor on the motor shaft that uses a magnet wheel and magnetic sensor to measure the rotation - and thus the motor's speed - as electrical pulses. These speed sensors are built directly onto the motor, where they are subjected to strong mechanical and thermal stresses that lead to wear and tear.
With the Sitrac system, a computer model helps calculate the rotational speed on the basis of the measured currents and voltage supply, and then uses these values to determine the torque required at any given moment. To adjust the torque, the system controls the inverter that supplies power to the rail vehicle's electric motor.
Besides ensuring less downtime, the system provides passengers with a more comfortable ride, as Sitrac generates less vibration than conventional systems. Its control technology is also more resistant to mechanical and electrical faults.
Sitrac is already in use in a number of cities across the globe. It can be adapted to almost any kind of train, from subways to long-distance transport systems, and regardless of whether trains run on direct or alternating current. Siemens offers special software that adapts the complicated control of the drive units to the power grid used.
For more information contact Siemens Southern Africa, +27 (0)11 652 2000.
Further reading:
The importance of power integrity
Spectrum Concepts
Power Electronics / Power Management
[Sponsored] Behind every high-speed system lies the need for power integrity. Without it, even the cleanest signal paths become compromised.
Read more...
Precise multi-vital sign monitoring
Future Electronics
Power Electronics / Power Management
The AS7058 by ams OSRAM is an integrated multi-vital sign monitoring device, which provides a complete photoplethysmogram, electrocardiogram, body impedance sensor, and electrodermal activity sensor.
Read more...
Automotive battery diagnostics tester
Comtest
Power Electronics / Power Management
Midtronics’ MVT handheld battery tester is a revolutionary tool, powered by MDX-AI, which is set to redefine the standards of battery diagnostics and testing in the automotive industry.
Read more...
Advanced 3-phase controllers
Future Electronics
Power Electronics / Power Management
The STSPIN32G0 by STMicroelectronics is a family of highly integrated system-in-package providing solution suitable for driving three-phase brushless motors.
Read more...
Converting high voltages without a transformer
Altron Arrow
Editor's Choice Power Electronics / Power Management
With appropriate power converter ICs, such as the LTC7897 from Analog Devices, many applications can be suitably powered without having to use complex and cost-intensive transformers.
Read more...
Reliable power for demanding applications
Conical Technologies
Power Electronics / Power Management
The Mibbo Power MTR480 three-phase DIN-rail power supply is engineered to meet stringent industrial automation requirements, offering dependable performance in environments where downtime is not an option.
Read more...
Powering performance and precision
Future Electronics
Power Electronics / Power Management
onsemi’s innovative T10 series MOSFETs, available in 40 V and 80 V versions, are designed for high-efficiency, fast-switching, and power-dense applications.
Read more...
Programmable flyback switcher ICs
Future Electronics
Power Electronics / Power Management
Power Integrations has announced the release of the InnoSwitch5-Pro family of programmable flyback switcher ICs, which offer more than 95% efficiency in streamlined AC-DC converter designs.
Read more...
Multilayer chip beads with 8 A rating
RS South Africa
Power Electronics / Power Management
TDK Corporation has expanded its MPZ1608-PH series of large-current multilayer chip beads for automotive and commercial power supply lines.
Read more...
The role of bidirectional charging in the evolving energy landscape
Avnet Silica
Power Electronics / Power Management
As reliance on renewable sources like wind and solar continues to grow, the need for efficient energy flow and storage solutions has become more critical than ever.
Read more...
printer friendly version