Control Unit

Overview Traction Governors

HARDWARE

Traction Control is presented as a wall/bulkhead mounted, folded and welded stainless steel enclosure of dimensions 500(W) x 700(H) x 110(D) (dimensions in mm.), material thickness 1.5mm. The unit weighs apx. 30kg.

Traction Control houses the following main components:

• Viking25 Controller
• Speedswitch pcb
• Protections module
• Interface circuitry

FUNCTIONALITY

Engine Protection

Engine Protection functions are performed by both the Viking 25 controller (processing project specific software) and hardwired circuitry within Traction Control.

The software provides the following engine protections:

• 1st stage protection through reduction of applied load based on defined sequences and measured engine parameter values, designed to avoid engine shutdown under fault conditions for as long as possible, whilst maintaining the engine within its safe operating envelope.
• 2nd stage protection through reduction of fueling rate to zero on detection of control system fault through diagnostic routines or on detection of measured parameters outside of the engines safe operating window.

The hardwired circuitry provides the following engine protections:

• Overspeed detection performed by Speedswitch pcb providing speed sensing independent of normal mode of speed control.
• 10 channels performing engine shutdown independent of the normal mode of engine stopping provided by the Protections Module. Commissioning and fault delay functions are configurable. Each channel is latched through local Reset push button.

Engine control

Engine Control functions are performed by the Viking25 controller within Traction Control, processing project specific software.

The software includes the following core functionality:

• Start interlocks based on input status and memory of previous events.
• Engine auxiliaries control during engine starting, running and stopping conditions
• Engine speed governing,
• Engine load modifier control output or available load status output as required by the power car arrangement. This load control is very important to achieving successful power car operation. By linking the control of traction load to the available power of the engine the system can ensure limitation to engine performance (eg. Charge air pressure fuel limitation) does not cause the engine to stall down.

The system can be programmed to provide optimised performance of the overall traction power system. Additional control functionality can be designed and implemented into the Viking 25 controller software to meet the power car requirements.