It consists of DC drive system and AC variable.

DC DRIVE SYSTEM

It rectifies the constant voltage and frequency AC power supply to the continuously adjustable DC power supply through controlling SCR element. The rectifying device is a three-phase full controlled rectifying bridge which is isolated apart from AC network through the breaker. The output of the rectifying bridge passes through the assigned contactor and supplies power to DC motor, so as to control drawworks, mud pump, rotary table or speed and torque of top drive system, to make stepless speed regulation and to meet the demand of drive.

AC VARIABLE FREQUENCY DRIVE SYSTEM

AC variable frequency drive system of drilling rig in the depth of 3000~12000m which developed on the base of SIEMENS, ABB, VACON and other frequency converters represents the highest level of the industry.

CONTROLLED OBJECTS

Main motors of drawworks, mud pump, rotary table and automatic driller.

PROTECTION FUNCTIONS

v  Frequency converter fault alarm, an emergency brake by controlling the hydraulic disc brake.　

v  Anti-Collision safe speed.

v  Over-current, short-circuit and lost AC input voltage protection.

v  Lost wind alarm of main motor, low pressure alarm of lubricating oil.

v  I2t monitoring.

v  Lock protection of motor.

v  Emergency shutdown.