High performance choppers for mining vehicles

Novel chopper configurations for traction control of mining vehicles powered by battery or rectified sources from 96 V to 360 VDC are described. Design considerations for a chopper mounted inside an explosion-proof housing suitable for shuttle cars and battery-operated scoops are presented as well as methods to minimize heat losses, optimize heat dissipation, and withstand mining environment conditions. Applications of choppers to continuous miners, long-wall shearers, and tracked haulage vehicles, such as portal buses and locomotives, are discussed. Bipolar transistors and IGBTs (insulated-gate bipolar transistors) are compared for suitability for traction choppers. It is concluded that DC/DC choppers offer improved performance for mining vehicles with series DC traction motors. They can be applied to either AC or DC supplies and offer the potential of using standard 250 A modules for a variety of mining vehicles