METHOD FOR CONTROLLING A DECELERATION PROCESS OF A DC MOTOR AND CONTROLLER

• Main Author: HOOGZAAD GIAN
• Format: Patent
• Language: English
• Published: 24.12.2009
• Subjects: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORSOR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION

The invention is directed to a method for controlling a deceleration process of a DC motor (20), wherein the DC motor (20) is driven by a bridge driver (18) coupled to a power supply (12) intended to provide a supply voltage VDD at a power supply output (14), the method comprising the following steps: applying a deceleration PWM signal to the bridge driver (18) for decelerating the DC motor (20), and controlling the bridge driver (18) such that a motor-induced back current is reduced, if the voltage at the power supply output (14) exceeds a voltage threshold which is higher than VDD. In accordance with the invention the step of controlling the bridge driver (18) such that a motor-induced back current is reduced, if the voltage at the power supply output (14) exceeds a voltage threshold which is higher than VDD comprises: if the voltage at the power supply output exceeds the voltage threshold, changing stepwise the pulse width of the deceleration PWM signal in a first direction until the voltage at the power supply (14) output reaches or falls below the voltage threshold, and then, if the voltage at the power supply output (14) has fallen below the voltage threshold, changing stepwise the pulse width of the deceleration PWM signal in a second direction opposite to the first direction until the voltage at the power supply output (14) again reaches or exceeds the voltage threshold. The invention is also directed to a controller suitable to carry out the above method.