Braking method for an electric motor

A computer program product embodied in a non-transitory computer-readable storage medium and comprising computer commands which, when stored hi a memory of a switching device and executed by the switching device, causes the switching device to output actuation commands to at least one semiconductor switch and to receive and process measured values, by:

• a) actuating the at least one semiconductor switch, which is arranged in parallel with an electromechanical switch, to reduce a current intensity in the electromechanical switch;
• b) opening the electromechanical switch;
• c) turning-off the at least one semiconductor switch for an adjustable period;
• d) determining a resulting torque of the electric motor;
• and
• e) determining an actuation time for braking the electric motor based on the resulting torque and actuating the at least one semiconductor switch at the actuation time,
• wherein the resulting torque is opposite a present direction of rotation of the electric motor at the actuation time.

A system comprising a first computer program product embodied in a non-transitory computer-readable storage medium and executed in a switching device, and a second computer program product embodied in a non-transitory computer-readable storage medium and executed in a superordinate control device, each of the first and second computer program products comprising computer commands which interact to cause the switching device to output actuation commands to at least one semiconductor switch and to receive and process measured values, by:

• a) actuating at least one semiconductor switch, which is arranged in parallel with an electromechanical switch;
• to reduce a current intensity in the electromechanical switch;
• b) opening the electromechanical switch;
• c) turning-off the at least one semiconductor switch for an adjustable period;
• d) determining a resulting torque of the electric motor;
• and
• e) determining an actuation time for braking the electric motor based on the resulting torque and actuating the at least one semiconductor switch at the actuation time,
• wherein the resulting torque is opposite a present direction of rotation of the electric motor at the actuation time.

A soft starter for controlling an electric motor, comprising:

• a semiconductor switch and an electromechanical switch connected in parallel with the semiconductor switch arranged in at least one phase,
• an internal control unit designed to actuate the semiconductor switch and the electromechanical switch, and
• a computer program product embodied in a non-transitory computer-readable storage medium and comprising computer commands which, when stored in a memory of the soft starter and executed by the soft starter, causes the soft starter to output actuation commands to the semiconductor switch and to receive and process measured values, by:
• a) actuating the semiconductor switch, which is arranged in parallel with an electromechanical switch, to reduce a current intensity in the electromechanical switch;
• b) opening the electromechanical switch;
• c) turning-off the at least one semiconductor switch for an adjustable period;
• d) determining a resulting torque of the electric motor;
• and
• e) determining an actuation time for braking the electric motor based on the resulting torque and actuating the at least one semiconductor switch at the actuation time,
• wherein the resulting torque is opposite a present direction of rotation of the electric motor at the actuation time.

An electric motor arrangement, comprising:

• an electric motor;
• and
• a soft starter connected to the electric motor controlling the electric motor, wherein the soft starter comprises a first memory storing computer commands of a first computer program product embodied in a non-transitory computer-readable storage medium and executing the computer commands, the soft starter being connected to a superordinate control device having a second memory in which a second computer program product embodied in a non-transitory computer-readable storage medium and having computer commands is stored for execution by the superordinate control device, with the first and second computer program products interacting to cause the soft starter to output actuation commands to at least one semiconductor switch and to receive and process measured values, by:
• a) actuating at least one semiconductor switch, which is arranged in parallel with an electromechanical switch, to reduce a current intensity in the electromechanical switch;
• b) opening the electromechanical switch;
• c) turning off the at least one semiconductor switch for an adjustable period;
• d) determining a resulting torque of the electric motor;
• and
• e) determining an actuation time for braking the electric motor based on the resulting torque and actuating the at least one semiconductor switch at the actuation time,
• wherein the resulting torque is opposite a present direction of rotation of the electric motor at the actuation time.