By actively reducing the current using a counter-voltage, the field current actual value can now follow the field current setpoint - even for steep acceleration ramps - and therefore overvoltages are avoided in the armature circuit. The problem with armature overvoltages when entering the field weakening range has now been resolved by selecting the two-quadrant field power section option.
This is the reason that for this particular application, the standard CUD is sufficient, which already has an integrated PROFIBUS interface. The technological control with current setpoint interface is realized in the higher-level control. The dynamic overload capability of the units is utilized to brake the drive when the paper web breaks. diameter, a four-quadrant converter was selected with a rated supply voltage of 690 V and a rated current of 1 500 A. As a result of instability in the control voltage supply, in the past, there were repeatedly failures that had a negative impact on the availability.Īs a result of the data of the existing motor and the customer specifications relating to acceleration and braking ramps, tambour roll weight and max. The customer explained that he repeatedly had problems with the existing converter relating to overvoltage in the motor armature circuit - and as a consequence, this resulted in tension fluctuations in the paper web when the motor goes into the field-weakening range. The following measured values and status displays are to be visualized in the drive cabinet door to facilitate fast and simple diagnostics for the service and maintenance personnel: Armature current, armature voltage, speed, field current, status messages - operation and fault.
The client specified PROFIBUS as the control and setpoint interface. The technological control is to be implemented in the higher-level PCS7 system. The power section is to be supplied from the existing 690 V supply. An unwinder for paper in a reeler-slitter is to be modernized - but the existing motor is to be kept.