Upgrading of electric drives of a cooling bench.
Upgrading of electric drives of a cooling bench (tube mill No.80) was targeted at replacement of converters and DC motors by frequency converters and AC motors.
The cooling bench line is equipped with four mechanisms:
- — drum-type ejecting device;
- — screw-type cooling rack;
- — chain-type cooling bed;
- — distribution header.
When moving through transport mechanisms a tube must be synchronously and accurately transferred from one mechanism to another and get to a preset position without any misalignments.
During implementation of the project the following activities were undertaken:
- — DC converters were replaced by Inovance MD500 frequency converters (package of commissioning works was provided too);
- — DC motors were replaced by asynchronous electric motors with pre-mounted LIR encoders, produced at «Vladimir electric motor maker»;
- — control station for the mechanisms of a drum-type ejecting device, screw- and chain-type cooling beds was replaced, including installation of up-to-date display an control units on it;
- — a new panel was mounted on a distribution header control station, including installation of up-to-date display and control units on it;
- — mounting decisions on installation of new AC motors were brought into effect;
- — a new cabinet with SIMATIC S7-300 controller was designed;
- — all cable products and sensors were replaced;
- — a cabinet with a backup frequency converter was designed and installed, which, should any of the main frequency converters fail, can be quickly connected to any of the mechanisms. In this case the parameters in a backup frequency converter that are responsible for control of various mechanisms are auto set;
- — a backup switchover cabinet for prompt connection of a backup frequency converter to any of the mechanisms was designed and installed.
The algorithm of synchronization between the drives was implemented by means of software in SIMATIC S7-300 controller.