Power control for battery-electric bicycles

Electric bicycles powered with nickel-metal hydride batteries offer a 100-km range between recharges, and have a potential of 300 km when polymer batteries become available. These vehicles, when implemented by installing power kits on existing bicycles, can offer low-coat, pollution-free transportation for bringing education, health services, and communication to remote areas in developing nations. Solar-photovoltaic battery charging can avoid fuel cost. A controller for an electric bicycle must deliver power that varies from zero to the propulsion-motor's rated peak, at motor speeds corresponding to bicycle speeds from zero to 48 km per hour (30 mph). With DC propulsion motors, power can be controlled with pulse-width-modulated transistors whilst AC motors need variable frequency. Requirements for electric-bicycle control were postulated and specific controller configurations were cosidered.<>