Propulsion for Offshore Applications
The propulsion systems for offshore, pipe and cable laying as well heavy lift jack-up vessels shall be designed with excellent dynamic characteristics carrying out changes in speed and reversals at manoeuvre and positioning at optimum speed.
The speed control of the propulsion and thruster motors is realized via frequency converters with pulse-with modulation (PWM) in HV- or LV-technology. The converters are designed (in the standard solution) with diode rectifier at the mains side, insulated gate bipolar transistor (IGBT) or integrated gate commutated thyristor inverter (IGCT) at the motor side, DC- capacitors in the intermediate circuit and control system.
Each PWM-Converter drive is equipped with a SAM Propulsion drive control panel. This panel controls and monitors the drive and provides the torque set value via bus connection to the PWM-Converter control. Additionally actual data e.g. measured values, alarms, etc. are received from the converter control for continuously data processing to be displayed at the 15” touch screen panel mounted in the front door. The SAM Propulsion control panel is also interfaced to the superior ships automation, control and monitoring system via serial data line.