DC power control system of drilling rig in the depth of 4000～9000m is an important component of the electric drilling rig. It consists of 5 parts such as diesel generator control system, DC transmission control system, driller operation control system, magnetic eddy current brake control system and AC motor control center. This system could rectify 600V AC voltage to 0～750V continuously adjustable DC voltage to drive the DC motor through stepless speed regulation. Through logical control toward the DC contactor, it could be switched to different assignment positions. It features efficient production, stable working, good dynamic performance, proportional load, easy operation, complete display and perfect protection functions.
The diesel generator control system and the AC motor control center of AC variable frequency control system of drilling rig in the depth of 3000～12000m is almost the same as that of DC control system. It adopts the advanced full digital variable frequency speed control and DC chopper technologies on motor drive and brake to make the speed regulation of the motor become more predominant and the operation become more simple; meanwhile it could reach a very high power factor within the range of speed control, therefore it has effectively improved the service power of diesel generator, with evident energy-saving effect. Thereinto, drilling rig in the depth of 12000m driven by AC variable frequency control motor is one of the most advanced rigs in the world.
MAJOR FUNCTIONS OF POWER CONTROL SYSTEM
v Accurately control the speed of diesel engine and the voltage of generator.
v Self-equalizing power when interconnected synchronous multi-generators are in operation.
v Power limitation could prevent the generator set from overload.
v Multiple protections of diesel generator set (under-voltage, over-voltage, over-current,short-circuit, under-frequency, over-frequency and reverse power).
v Broad adjusting range and accurate control of speed could be completely satisfied with the requirements of drilling technology and various manufacturing machines.
v It utilizes PLC techniques to carry out controlling, monitoring and remote communication.
v Dynamic brake of drawworks and rotary table.
v Anti-slip protection of belt pulley.
v Zero interlocking protection.
v Magnetic eddy current brake control.
v Automatic driller.
v Traveling block saver.
v Integrated drilling instruments.
