Dynamic load-sharing power system

Abstract

A power system is provided for a marine or petroleum drilling vessel. The power system may have a plurality of power sources, at least one power consumer, and an input device configured to generate a signal indicative of a desired output. The power system may also have a load manager associated with the at least one power consumer and configured to create a power demand for the plurality of power sources based on the signal and an actual output, and a controller. The controller may be configured to determine a plurality of performance goals for the plurality of power sources, determine a priority of the performance goals, retrieve from the plurality of power sources at least one performance map corresponding with each performance goal, and selectively apportion the power demand between of each of the plurality of power sources based on the at least one performance map and based on the determined priority.

What is claimed is: 
     
         1 . A power system, comprising:
 a plurality of power sources;   at least one power consumer driven by the plurality of power sources;   an input device configured to generate a signal indicative of a desired output of the at least one power consumer;   a load manager associated with the at least one power consumer and configured to create a power demand for the plurality of power sources based on the signal and an actual output of the power consumer; and   a controller in communication with the load manager and the plurality of power sources, the controller being configured to:
 determine a plurality of performance goals for the plurality of power sources; 
 determine a priority of the plurality of performance goals; 
 retrieve from each of the plurality of power sources at least one performance map corresponding with each of the plurality of performance goals; and 
 selectively apportion the power demand between of each of the plurality of power sources based on the at least one performance map and based on the determined priority. 
   
     
     
         2 . The power system of  claim 1 , wherein the plurality of power sources includes a plurality of engines. 
     
     
         3 . The power system of  claim 2 , wherein at least one of the plurality of power sources further includes a generator mechanically driven by one of the plurality of engines. 
     
     
         4 . The power system of  claim 2 , wherein the plurality of engines includes engines having different output capabilities. 
     
     
         5 . The power system of  claim 2 , wherein the at least one power consumer includes at least one of a propeller of a marine vessel and auxiliary loads of the marine vessel. 
     
     
         6 . The power system of  claim 2 , wherein the plurality of performance goals are associated with transient response, fuel consumption, emissions, and engine wear. 
     
     
         7 . The power system of  claim 6 , wherein the priority is operator selectable. 
     
     
         8 . The power system of  claim 6 , wherein:
 the power system is associated with a marine vessel; and   the priority is automatically selected based on a current operation of the marine vessel.   
     
     
         9 . The power system of  claim 8 , wherein:
 the current operation is one of a deep dynamic positioning operation, a pulling operation, and a port operation; and   the plurality of performance goals include low fuel consumption, high transient response, and low emissions.   
     
     
         10 . The power system of  claim 9 , wherein:
 when the current operation is a deep dynamic positioning operation, the priority of the plurality of performance goals includes high transient response, then fuel consumption, then emissions;   when the current operation is a pulling operation, the priority of the plurality of performance goals is low fuel consumption, then transient response, then emissions; and   when the current operation is a port operation, the priority of the plurality of performance goals is low emissions, then fuel consumption, then transient response.   
     
     
         11 . The power system of  claim 9 , wherein each different operation has a different power demand apportionment between the plurality of power sources. 
     
     
         12 . The power system of  claim 1 , wherein the controller is configured to selectively apportion the power demand based further on monitored performances of the plurality of power sources. 
     
     
         13 . The power system of  claim 12 , wherein the monitored performances include at least one of fuel flow, rpm, torque, inlet manifold air pressure, and inlet manifold air temperature. 
     
     
         14 . The power system of  claim 1 , wherein the controller is further configured to selectively apportion the power demand based further on a desired power reserve. 
     
     
         15 . The power system of  claim 1 , further including a display located within an operator station, wherein the controller is further configured to show on the display how the power demand is apportioned. 
     
     
         16 . The power system of  claim 1 , wherein:
 the power system is associated with a marine vessel; and   the controller is configured to selectively apportion the power demand based also on wind and water currents affecting the marine vessel.   
     
     
         17 . The power system of  claim 1 , wherein the controller is further configured to:
 determine performance drift of the plurality of power sources away from the at least one performance map; and   selectively allow apportionment of the power demand based on the performance drift.   
     
     
         18 . The power system of  claim 1 , wherein the controller is configured to apportion the power demand unequally between the plurality of power sources. 
     
     
         19 . A control network for a power system having a plurality of engines, a plurality of generators driven by the plurality of engines, and at least one electrical load driven by the plurality of generators, the control network comprising:
 a load manager configured to receive input from an operator of the power system indicative of a desired output of the at least one electrical load and to responsively create a power demand for the plurality of generators based on the input and an actual output of the at least one electrical load;   an engine controller associated with each of the plurality of engines; and   a power system controller in communication with the load manager and the engine controller of each of the plurality of engines, the power system controller configured to:
 determine at least one performance goal for the plurality of engines associated with at least one of fuel consumption, emissions, and transient response; 
 retrieve from each of the engine controllers of each of the plurality of engines a performance map corresponding with the performance goal; 
 determine a priority for the at least one performance goal; and 
 selectively apportion the power demand unequally between of each of the plurality of engines based on the performance map and based on the determined priority. 
   
     
     
         20 . A method of controlling a power system, comprising:
 operating a plurality of engines to power a propeller and auxiliary loads of a marine vessel;   receiving a signal indicative of a desired output of the propeller and the auxiliary loads;   creating a power demand for the plurality of engines based on the signal and an actual power output of the propeller and auxiliary loads;   determining a plurality of performance goals for the plurality of engines associated with at least one of fuel consumption, emissions, and transient response;   prioritizing the plurality of performance goals;   retrieving from each of the plurality of engines at least one performance map corresponding to the plurality of performance goals; and   selectively apportioning the power demand unequally between of each of the plurality of engines based on the at least one performance map and a priority of the plurality of performance goals.