Patent ID: 7325498

Claim:
A method for retrofitting an existing energy Off Highway Vehicle propulsion circuit such that the retrofitted propulsion circuit operates as an hybrid energy Off Highway Vehicle propulsion circuit, said existing vehicle propulsion circuit including a traction motor controlling a rotational speed of at least one wheel for propelling an Off Highway Vehicle, said traction motor having a dissipation mode of operation and a motoring mode of operation and driven by an engine providing primary electric power, wherein said first traction motor propels the Off Highway Vehicle in response to the primary electric power when operating in the motoring mode, and wherein said traction motor generates dynamic braking electrical power which is dissipated in an electrical resistance system to decrease the rotational speed of the at least one wheel when operating in the dissipating mode, and thereby, decrease the speed of the Off Highway Vehicle, said electrical resistance system including at a first resistor grid circuit and a second resistor grid circuit, wherein each of the first and second grid circuits includes one or more resistors and an auxiliary switching device, said method comprising: disconnecting an auxiliary switch from the first resistor grid circuit; installing a two position switch in the first resistor grid circuit; disconnecting one or more resistors from the second resistor grid circuit; installing a first energy storage device in the second resistor grid circuit, said auxiliary switching device in the second resistor grid circuit being responsive to dynamic braking electrical power generated in the traction motor during the power dissipation mode to transfer a portion of the dynamic braking electrical power to the first energy storage device; and storing the transferred portion of braking electrical power in the first energy storage device as secondary power.