An apparatus and method for controlling current in an electric supercharger

摘要

Disclosed is a method of controlling a motor in an electric supercharger when instructed to increase the speed of the motor to a target speed 2. The method comprises the steps of repeatedly: (i) calculating an adjusted target speed 13, (ii) determining the difference between the adjusted target speed 13 and the actual speed 4 of the motor, (iii) determining a torque set-point 10 for changing the speed of the motor from the actual speed 4 towards the adjusted target speed 13 and (iv) supplying electrical current to the motor dependent on the torque set point 10. The adjusted target speed 13 is calculated as a function of the time elapsed since the instruction to increase the speed, the function being such that, over a response time, the adjusted target speed 13 approaches the target speed 2. The supercharger may be used to supply air to an internal combustion engine. A Control system using the method is also disclosed. The method provides smooth approach to a demanded supercharger speed and prevents overshoot of the target speed.