The enterprise has a many years’ experience in modernization of high-powered electric drives under running production conditions at metallurgical and ore mining plants.
The objects of modernization are the electric drives of complicated and high-powered machines applied in ferrous and non-ferrous metallurgy (electric drives of breakdown and finishing stands, electric drives of piercing, sizing and reducing mills, electric drives of section mills, of a coiler, etc.) and in metal mining industry (skip and cage windings, crushing units, etc.).
Modernization of electric drives may involve replacement of all or some part of electrical equipment. Obsolete and worn-out converters with analog pulse-phase control and automatic speed control systems are replaced by the new converters with microprocessor-based control systems.
At Customer’s request the following modernization options for high-powered dc drives are available:
- — complete replacement of electrical converter equipment, involving the use of the state-of-the-art modules that include a power part and all control and protection systems, based on microprocessor units;
- — replacement of drive control and protection systems only, while retaining the existent power part (gate section cabinets). In order to provide interfacing between the new and the old equipment, the dedicated devices are designed (for current and voltage measuring systems, systems of pulse distribution to power thyristors, etc.).
- — complete replacement of electrical converter equipment, involving the use of the up-to-date modules that include the control and protection systems only, based on microprocessor units (upgrade modules), and a power part (gate sections) manufactured at our enterprise.
By now we have gathered a wealth of experience in manufacture and safe operation of gate sections. The sections are manufactured as object-oriented products that fit with the overall dimensions and ways of connection to them of the existent buses and cables. The gate sections are either forced air-cooled or water-cooled. The water treatment systems can be left as they are or be replaced by the new modern ones. The power part is executed according to a six-pulse or a twelve-pulse rectification circuit. High-powered electric drives (up to 10000 A, 1050 V) are implemented on basis of reversing gate sections rated for 2500 A, 1050 V and built according to a Master-Slave principle, with a twelve-pulse rectification.
With the aid of a microprocessor-based control system one can integrate an updated electric drive into the process automation structure at a state-of-the-art level, thus enabling the build of a complex drive control system for a production machine.
When it comes to rolling mill drives, a converter update will allow you to implement, in particular, such systems as:
- — Mill acceleration control system.
- — Automatic gage and tension control system.
- — Automatic draft control system.