Automotive Electrical System Configuration

Abstract

Disclosed herein are a variety of different electrical system topologies intended to mitigate the impact of large intermittent loads on a 12 volt vehicle power distribution system. In some embodiments the intermittent load is disconnected from the remainder of the system and the voltage supplied to this load is allowed to fluctuate. In other embodiments, the voltage to critical loads is regulated independently of the voltage supplied to the remainder of the system. The different topologies described can be grouped into three categories, each corresponding to a different solution technique. One approach is to regulate the voltage to the critical loads. A second approach is to isolate the intermittent load that causes the drop in system voltage. The third approach is to use a different type of alternator that has a faster response than the conventional Lundell wound field machine.

1 - 26 . (canceled) 
     
     
         27 . Apparatus comprising:
 a main bus;   an engine-driven electrical-energy source that is configured to supply electrical energy to the main bus;   a secondary bus;   a first electrical load electrically coupled to the secondary bus;   a battery electrically coupled to the secondary bus;   a first bi-directional direct-current-to-direct-current (“DC-DC”) converter that is configured to electrically couple the main bus to the battery and to the first electrical load;   a second bi-directional DC-DC converter that is configured to electrically isolate the main bus from an ultracapacitor;   at least one additional electrical load electrically coupled to the main bus other than through the first bi-directional DC-DC converter; and   wherein the first bi-directional DC-DC converter is configured to control current flow between the main bus and the secondary bus in response to a main-bus voltage level and a secondary-bus voltage level.   
     
     
         28 . The apparatus of  claim 27 , wherein the engine-driven electrical-energy source is selected from the group consisting of: an alternator and a generator. 
     
     
         29 . Apparatus comprising:
 a main bus;   an engine-driven electrical-energy source that is configured to   supply electrical energy to the main bus;   a secondary bus;   a first electrical load electrically coupled to the secondary bus;   a battery electrically coupled to the secondary bus;   a first bi-directional direct-current-to-direct-current (“DC-DC”) converter that is configured to electrically couple the main bus to the battery and to the first electrical load;   a second bi-directional DC-DC converter that is configured to electrically isolate the main bus from an ultracapacitor; at least one additional electrical load electrically coupled to the ultracapacitor other than through the second bi-directional DC-DC converter; and   wherein the first bi-directional DC-DC converter is configured to control current flow between the main bus and the secondary bus in response to a main-bus voltage level and a secondary-bus voltage level.   
     
     
         30 . The apparatus of  claim 29 , wherein the engine-driven electrical-energy source is selected from the group consisting of: an alternator and a generator. 
     
     
         31 . Apparatus comprising:
 a main bus;   an engine-driven electrical-energy source that is configured to   supply electrical energy to the main bus;   a secondary bus;   a first electrical load electrically coupled to the secondary bus;   a battery electrically coupled to the secondary bus;   a first bi-directional direct-current-to-direct-current (“DC-DC”) converter that is configured to electrically couple the main bus to the battery and to the first electrical load;   a second bi-directional DC-DC converter that is configured to electrically isolate the main bus from an ultracapacitor; at least a first additional electrical load electrically coupled to the main bus other than through the first bi-directional DC-DC converter and electrically coupled a first side of the second bi-directional DC-DC converter;   at least a second additional electrical load electrically coupled to the ultracapacitor other than through the second bi-directional DC-DC converter and electrically coupled to the second side of the second bidirectional DC-DC converter; and   wherein the first bi-directional DC-DC converter is configured to control current flow between the main bus and the secondary bus in response to a main-bus voltage level and a secondary-bus voltage level.   
     
     
         32 . The apparatus of  claim 31 , wherein the engine-driven electrical-energy source is selected from the group consisting of: an alternator and a generator.