Method and apparatus for electrical bus centering

An aircraft electrical power distribution system that includes a positive bus rail, a negative bus rail, and a ground, said system comprising:

• a power source;
• a load;
• and
• a bus centering device comprising:
• a central node;
• a first switching component configured to couple the central node to the positive bus rail for a first predetermined duty cycle;
• a second switching component configured to couple the central node to the negative bus rail for a second predetermined duty cycle;
• an inductive component coupled between the central node and ground, said inductive component configured to maintain a voltage at the central node substantially equal to ground potential, wherein a voltage between the positive bus rail and the central node is maintained substantially equal to a voltage between the negative bus rail and the central node;
• a first current limiting device coupled to said first switching component and said inductive component, said first current limiting device configured to maintain a continuity of current from said inductive component when said first switching component is turned off;
• and
• a second current limiting device coupled to said second switching component and said inductive component, said second current limiting device configured to maintain a continuity of current from said inductive component when said second switching component is turned off.

A method for centering an aircraft electrical power distribution system that includes a positive bus rail, a negative bus rail, and a ground, said method comprising:

• providing a power source and a load that is coupled to the power source;
• coupling a bus centering device to the positive bus rail, the negative bus rail, and the ground, the bus centering device includes:
• a central node;
• a first switching component, a second switching component, and an inductive component, the inductive component is coupled between the central node and ground;
• coupling the central node to the positive bus rail for a first predetermined duty cycle;
• coupling the central node to the negative bus rail for a second predetermined duty cycle;
• and
• maintaining a voltage at the central node substantially equal to ground potential, wherein a voltage between the positive bus rail and the central node is maintained substantially equal to a voltage between the negative bus rail and the central node.