SIEMENS has launched the ECO-RTG control which it claims can improve the energy efficiency and control of diesel-electric hybrid drives in rubber-tired gantry cranes.
When containers are lowered by the cranes, braking energy is stored in ultra-capacitors. According to the company, it has optimised the control system with simulation tools and drive algorithms to further improve energy efficiency.
The system applies an energy management strategy to monitor the amount of energy supplied from the motor/generator units and ultra-capacitors. This is said to utilise as much energy as possible from the ultra-capacitors, while ensuring the stored energy is never completely used up.
The manufacturer claims the Equivalent Consumption Minimisation Strategy is based on a mathematical model of the motor and the ultra-capacitors, in order to determine the exact performance setpoint value in real time, ensuring minimum fuel consumption.
Siemens says the control function will continuously adjust energy consumption in changing conditions, by means of approximations and permanent adaptations.