Braking force controller and control method for electric car

摘要

In order to keep the braking torque of a motor always maximal and to execute suitable ABS regenerative braking, a controller of an electric car has a motor (1) connected to the road wheels, and its central controller confirms that regenerative energy calculated from output signals from an ammeter (51) and from a volt meter (52) after the braking operation begins reaches a maximum value, and stores a braking torque calculation value obtained from a signal from a motor number-of-revolution sensor (63), as a maximum braking torque value. When the difference between the braking torque command value applied to the motor (1) and the braking torque calculation value exists within a predetermined range, the braking torque command value is thereafter increased or decreased in accordance with the difference between the maximum braking torque value described above and a present braking torque calculation value, and when the difference is out of this predetermined range, the braking torque command value is decreased.