AC propulsion: the future for North American traction

After many years of development and proven success in Europe, the switch is on to AC propulsion in North America. Transit authorities procuring and rehabilitating self-propelled transit vehicles and locomotives are now giving AC propulsion the consideration it deserves. The three-phase AC drive for transit applications has proven itself in the hundreds of systems operating in Europe. The first AC equipped vehicles supplied to the North American market are in reliable revenue service. The advantages of AC propulsion in terms of cost and performance have become recognized and widely publicized in the US. The driving forces behind this popularity are clear: low operating costs and increased reliability. Today, the initial cost of an AC propulsion system will likely be greater than or equal to that of a contemporary DC chopper system and definitely more than a switched resistance system. However, the additional cost of an AC system can be readily justified by giving proper consideration to the life cycle costs. The improved reliability and dramatically reduced maintenance required decrease the operating costs associated with the equipment after the initial procurement