Propulsion system

Abstract

A system for automatically controlling the speed of a battery powered electric propulsion motor driving a shaft connected to a propeller located on a sailing vessel. The system includes a user interface for selecting either a neutral, a regeneration or a forward thrust operating mode. The system also includes a controller configured to receive input from a motor speed sensor and a motor current sensor. The controller adjust the speed of the motor to the correct motor speed. The controller is configured so that in the neutral mode the correct motor speed is the speed required to substantially eliminate thrust on the shaft.

1 . A system for controlling an electric propulsion motor for driving a propeller of a sailing vessel, the system comprising:
 a user interface for selecting either a sail mode or a normal operation mode;   a controller configured to operate in the sail mode to control the electric propulsion motor to substantially eliminate the drag force being applied by the propeller to the vessel.   
     
     
         2 . A system for automatically controlling the speed of a battery powered electric propulsion motor driving a shaft connected to a propeller located on a sailing vessel comprising:
 a user interface for selecting an operating mode of the system;   a motor speed sensor;   a controller configured to receive input from the motor speed sensor and adjusts the speed of the motor to the correct motor speed; and   wherein the controller executes an algorithm to determine the correct motor speed based on the selected operating mode.   wherein the operating modes include neutral, regeneration and forward thrust modes;   wherein the controller is configured so that in the neutral mode the correct motor speed is the speed required to substantially eliminate thrust on the shaft.   
     
     
         3 . The system of  claim 2 , wherein the system is configured so that selection of the regeneration mode includes selecting a desired amount of power generation and wherein the controller is configured so that in the regeneration mode the correct motor speed is the speed required to produce the desired amount of power generation with the minimum amount of thrust on the shaft. 
     
     
         4 . The system of  claim 2 , wherein the system is configured so that when the regeneration mode is selected the controller is configured to adjust the motor speed to produce the maximum amount of power generation without exceeding a maximum amount of drag. 
     
     
         5 . The system of  claim 2 , wherein system is configured so that when the forward thrust mode is selected the user interface permits the selection of a minimum transit speed of the vessel and the controller operates to adjust the motor speed to so that the minimum transit speed is achieved. 
     
     
         6 . The system of  claim 2 , wherein the system is configured so that when the forward thrust mode is selected the user interface permits the selection of an additional power boost and the motor speed is controlled based on the amount of power boost selected. 
     
     
         7 . The system of  claim 6 , wherein the controller adjusts the motor speed based on both the power boost selected and the remaining capacity of the battery. 
     
     
         8 . The system of  claim 6 , wherein user interface permits selection of the duration of the voyage and the controller adjust the motor speed based on both the power boost selected and the duration of the voyage selected by the user. 
     
     
         9 . The system of  claim 2 , wherein the system is configured so that selection of the forward thrust mode includes selecting a desired amount of forward thrust and wherein the controller is configured so that in the forward thrust mode the correct motor speed is the speed required to produce the desired amount of forward thrust on the shaft. 
     
     
         10 . The system of  claim 2 , wherein the controller adjusts the motor speed by adjusting a current to the motor. 
     
     
         11 . The system of  claim 9 , further comprising a pressure sensor for measuring the forward thrust on the shaft. 
     
     
         12 . The system of  claim 9 , wherein the system is configured so that when the desired amount of thrust is selected the controller determines a corresponding amount of current to be supplied to the motor. 
     
     
         13 . A system for automatically controlling the speed of a battery powered electric propulsion motor located on a sailing vessel comprising:
 a user interface for selecting an operating mode of the system;   a motor speed sensor;   a controller configured to receive input from the motor speed sensor and adjusts the speed of the motor to the correct motor speed; and   wherein the controller executes an algorithm to determine the correct motor speed based on the selected operating mode.   
     
     
         14 . The system of  claim 13 , wherein the algorithm considers the operating characteristics of the vessel when determining the correct motor speed. 
     
     
         15 . The system of  claim 13 , wherein the system is configured so that the user interface does not permit the user to directly select vessel speed or motor speed 
     
     
         16 . The system of  claim 13 , wherein the algorithm includes a learning function to determine certain operating characteristics of the vessel. 
     
     
         17 . The system of  claim 13 , further comprising a motor current sensor and wherein the controller is configured to receive input from the motor current sensor and wherein the controller adjusts the motor current in order to control the motor speed. 
     
     
         18 . A system for automatically controlling the speed of a battery powered electric propulsion motor driving a shaft connected to a propeller located on a sailing vessel comprising:
 a user interface for selecting transit speed for the vessel;   a motor speed sensor and a motor current sensor;   a controller configured to receive input from the motor speed sensor and the motor current sensor and adjusts the speed of the motor to the correct motor speed; and   wherein the controller executes an algorithm to determine the operating mode necessary to achieve the selected transit speed;   wherein the operating modes include regeneration and forward thrust modes;   wherein the controller is configured to shift the motor between the regeneration and forward thrust modes as necessary to maintain the selected transit speed.