Method and circuit assembly for current control in 3-phase motors

摘要

A method and circuit assembly are provided for controlling the motor current in an electric 3-phase motor, in particular in a 3-phase stepper motor, by a chopper process. For at least two of the three motor connections a respective chopper phase is cyclically activated, while a target motor current supplied for the motor connection in question is injected into the motor connection by a chopper process, while the two other motor connections are connected to each other.

主权项

1. Method for controlling the motor current in an electrical 3-phase motor, with a first, a second and a third motor connection, comprising
activating a first, a second and a third chopper phase in cyclically alternating fashion, wherein during each chopper phase the motor is connected between a supply voltage and ground, namely with one of the first, the second and the third motor connection and with two other motor connections of the first, the second and the third motor connection which are connected with each other, and injecting, during at least two of the three chopper phases, a target current supplied for the one of the first, second, and third motor connection into the one of the first, second, or third motor connection by a chopper process, and comparing, during each chopper phase, a supplied instantaneous motor target current for the one motor connection with a de facto instantaneous motor current at this motor connection, and activating, dimensioning, and combining through the chopper process, in dependence on a difference between these two currents, ON and FD motor current phases so that the de facto motor current follows the motor target current.