Vessel energy management system

A method of vessel energy management for controlling power supply to and from a propulsion system of a vessel, the method comprising:

• receiving power at a motor-generator unit from a prime mover of the vessel;
• determining an instantaneous power requirement of the propulsion system of the vessel;
• determining an average power generated by the prime mover;
• comparing the instantaneous power requirement and the average power and providing a result;
• when the instantaneous power requirement exceeds the average power based on the result, causing the motor-generator unit to receive energy from capacitors, super capacitors, or ultra capacitors, chemical energy storage, batteries, or flywheel energy storage, of an energy storage unit;
• when the instantaneous power requirement is less than the average power based on the result, causing the motor-generator unit to supply power from the prime mover to the capacitors, the super capacitors, or the ultra capacitors, the chemical energy storage, the batteries, or the flywheel energy storage, of the energy storage unit;
• and
• monitoring the instantaneous power requirement and the average power in varying sea conditions and adapting accordingly.

A vessel energy management system for controlling power supply to and from a propulsion system of a vessel, the vessel energy management system comprising:

• a prime mover supplying power to a shaft;
• a motor-generator unit adapted to receive power from the shaft;
• an energy storage unit;
• a frequency converter for converting energy from the motor-generator unit for supply to consumers or for supply to the energy storage unit;
• a controller;
• wherein the energy storage unit comprises one or more capacitors, super capacitors or ultra capacitors, chemical energy storage, batteries, or flywheel energy storage;
• wherein the controller determines an instantaneous power requirement of the propulsion system and an average power generated by the prime mover;
• an estimator for estimating when to take power from the shaft and when to supply power to the shaft;
• a comparator to compare the instantaneous power requirement and the average power and provide a result;
• wherein when the instantaneous power requirement exceeds the average power based on the result, the motor-generator unit receives energy from the energy storage unit or from an auxiliary generator to augment power supplied by the prime mover, wherein a timing of when to supply energy to the motor-generator unit is determined by the estimator;
• and
• wherein when the instantaneous power requirement is less than the average power based on the result, the motor-generator unit supplies power from the prime mover to the energy storage unit or to consumers, wherein a timing of when to supply power to the energy storage unit or to consumers is determined by the estimator.