Production and delivery of VFD block-box and MCC block-box fo r drilling rig БУ-AR-247-5000/320.
In accordance with the terms of reference by OOO Bentec, the city of Tyumen, and in a short time frame, there were designed, produced and tested using a trial assembly the VFD and MCC block-boxes, intended to control the equipment of a newly fabricated drilling rig БУ-AR-247-5000/320.
The block-boxes are made as ready-made large-block electrical modules, consisting of a heat-insulated enclosure, base and internal electrical equipment cabinets. At the facility in question the block-boxes are installed in a drilling rig echelon, by way of two storeyes; the lower VFD block-box has a reinforced frame and implies the upper MCC block-box to be installed directly on it without using any dedicated landing platforms, which cuts the installation time and reduces the transportation junctions.
VFD block—box.
The VFD block-box is designed to operate while a part of a drilling rig as an incoming supply distribution assembly, intended to receive and distribute the electrical power of ~690V, 50Hz, 5MVA, and as a complete converter unit, intended to energize and control the AC motors of main drives of a drilling rig.
The electric drives of main machines of a drilling rig are built according to a multi-drive scheme, based on frequency converters of «VARIANT-AC» series, manufactured by AO ASC (Joint Stock Company). The converter assembly includes two independent lead-in cabinets with each power input rated for 2500A, a common rectifier, consisting of 6 rectifier modules with a total power of 6MW, six control cabinets with inverters for main drives of a dual-motor winch (two cabinets with inverter modules 900kW each) and two dual-motor drilling pumps (four cabinets with inverter modules 900kW each). The converter also includes a common three-phase brake module (chopper) with a continuous dissipated power of 1300kW. A common rectifier unit is built on basis of six modules В-МППД-1000-1000-УХЛ4 (1000kW, 1000A); the circuit provides for operation underpowered in the event of failure of one or two rectifier modules. The cabinets with inverters for control of one motor (of a winch and pump) include two inverter modules И-ПТПТ-450-690-50-УХЛ4 (450 kW, 450A); should one of the modules becomes faulty, operation underpowered is provided. The control system for main drives of a winch and drilling pumps provides for operation of two motors in a «master-slave» mode, and also for a single drive mode in the event of failure of one of the motors.
MCC block—box.
The MCC block-box is designed to operate while a part of a drilling rig as an incoming supply distribution assembly, intended to distribute the electrical power of ~400V, 50Hz, and as a complete control unit for auxiliary machines, supplying power to electric motors of auxiliary machines of a pump block, derrick drawwork unit, drilling mud preparation and cleaning unit.
To compensate for reactive component, an automatic PF correction ~400V, 500kVAr is envisaged.
