Figure 1.1 VFD house layout

VFD house mainly contains:

u  4 generator cabinets and 1 synchronizing cabinet

    Function: they are used for paralleling and controlling 4 diesel generators and supply 600V/50Hz AC power to the system. A Schneider MT breaker is mounted in synchronizing cabinet, and it is used for supplying AC 600V/50Hz power to top drive.

u  3 SIEMENS rectifying systems

    Function: they are used for rectifying AC 600V current to 840V DC power and supply DC power to inverting cabinet.

u  6 SIEMENS inverting equipments

    Function: 2 drawworks (DW) inverting equipments, 3 mud pump (MP) inverting equipments and 1 rotary table (RT) inverting equipment supply power for AC viable frequency motors.

u  2 SIEMENS brake cabinets and relevant resistors

    Function: they build up brake control of surplus energy consumption and surplus energy consumption unit. They are used for exhausting feedback energy from inverting equipments on DC bus.

u  1 PLC cabinet

    Function: 2 independent S7-300 control systems are mounted in the cabinet. By gathering digital data and analog data, via CPU logic calculation, they can fulfill integrated control of the whole system. A-B touch screen is mounted on door of the cabinet, and real-time drilling parameter can be attained by different interface, as well as data recording can be looked up.

u  1 switch cabinet (Switch cabinet)

    Function: 3 MT switch is mounted in the cabinet. one is used for supplying AC 600V power to T1 transformer. Besides, the second one is used for T1 transformer output; The third one is used for auxiliary generator.

u  1 auto-bit cabinet and relevant resistor

    Function: it is equipped a Siemens S120 single transmission converter, and it used for supply power for auto-bit motor; The brake resistor is used for exhausting feedback energy when auto-bit motor is lowering traveling block. This equipment is designed for providing constant drilling speed and drilling pressure for shallow formation, formation with unstable well pressure and formation required low drilling speed.

u  4 MCC cabinet

    Function: it is used for supplying 400VAC dynamic power to blowers, oil pumps of DW, RT, MP and mud tank etc.

u  1 high-power air conditioner

    Function: the system applies 1 Trane cooling air conditioner to adjust indoor temperature of VFD house.

u  4 MCC cabinets

    Function: they are used for supplying power to AC motors of drilling floor, MUD PUMP house, MUD tank area, oil tank area, generator house and water tank area etc.

u  1 lighting cabinet

    Function: plastic breakers are mounted in lighting cabinet, and it supplies 400V power to system and 220VAC lighting power and supplies 220VAC/24VDC power to driving part. Siemens touch screen is installed too.

u  1 transformers

    Function: T1 transformer (600VAC/400VAC, 1250KVA) supplies 400VAC power to the whole drilling field.