1. Overview of Electrical Control System for Drilling Machines The DC control system of electric drilling rig includes five parts: diesel generator set control unit, DC transmission control unit, driller operation control unit, electromagnetic brake control unit, and AC motor control center. The system is stable in operation, with good dynamic performance, high production efficiency, balanced load, simple operation, complete display, and complete safety protection functions. The AC variable frequency control system for electric drilling rigs has a diesel generator set control unit and an AC motor control center that are basically the same as the DC control system. The difference lies in the use of advanced fully digital variable frequency speed regulation technology and DC chopping technology in the motor drive and braking parts, which makes the motor's speed regulation performance more superior, the system operation more convenient, the power factor is high, and can effectively improve the power of diesel generators, with obvious energy-saving effects. 2. The main functions and characteristics of the drilling rig electrical control system are to accurately control the diesel engine speed and generator voltage; Automatic balancing of power when multiple generators are connected to the grid for operation; Power limitation can prevent unit overload; Equipped with multiple protection functions for diesel generator sets (under voltage, over voltage, over current, short circuit, under frequency, over frequency, and reverse power); Wide speed regulation range and precise speed control can fully meet the requirements of different drilling processes; Using PLC technology for control, monitoring, and remote communication; The winch and turntable adopt energy consumption braking; Belt pulley anti slip protection (DC drilling rig); Zero position interlocking protection; Electromagnetic eddy current brake control (DC drilling rig); Automatic drilling; Anti collision of traveling block; Integrated drilling instruments; 3. The main components of the drilling rig electrical control system Diesel generator control system The diesel generator control system is used to control the diesel generator set and output an AC voltage of 600V and 50Hz. The system is divided into two types: analog power generation control and fully digital power generation control systems. The analog control system consists of circuit breakers, synchronization devices, AC control components, power limiting circuits, and ground fault detection circuits; The fully digital power generation control system mainly consists of a WOODWARD EGCP-2 generator control module and a 2301D engine speed controller. drive system The transmission system is divided into two types: DC transmission and AC variable frequency transmission. DC transmission system: used to control SCR components and convert constant voltage and frequency AC power supplies into continuously adjustable DC power. Three-phase fully controlled rectifier bridge rectification, circuit breaker isolated from AC power grid, its output is supplied to DC motor through designated contactor, achieving speed and torque control of drilling rig winch, mud pump, rotary table or top drive, and can be stepless speed regulation to meet transmission requirements. The AC variable frequency control system mainly includes: independent variable frequency motor automatic drilling and main motor drilling; High power energy consumption braking system for drawworks; Intelligent integrated driller control; Intelligent traveling block position control system; MCC intelligent soft start and real-time monitoring; AC incoming line impedance capacitance absorption; Remote communication equipment management platform, etc. The control objects are the main motor of the winch, the main motor of the mud pump, the main motor of the rotary table, and the automatic drilling motor. The system can achieve frequency converter fault alarm and control hydraulic disc brake emergency braking; Overcurrent, short circuit, and AC input voltage loss protection; Main motor loss of wind alarm, lubricating oil low pressure alarm; I2t monitoring; Motor locking protection and emergency shutdown protection functions. The DC control system of the energy consumption braking unit can slow down the high-speed running motor, and the handwheel controls the speed of the cat head. Just release the foot control by the driller, and after a delay, the energy consumption braking will automatically start, saving tripping time. Under the motor power generation condition of the AC variable frequency control system, the braking unit and braking resistor automatically generate energy consumption braking, which can achieve stable and adjustable suspension of the drilling tool and prevent reverse rotation of the rotary table. Automatic drilling unit constant pressure (WOB)/constant speed (ROB) automatic drilling is a dual closed-loop control system with rotational speed and current, which has functions such as drilling pressure, drilling speed, rotational speed, and upper limit of rotary distance. By using this system, drilling quality can be significantly improved, drilling speed can be accelerated, labor intensity of workers can be reduced, and drill bit life can be extended. Integrated control system Driller's operation control system Data transmission is carried out through PLC and PROFIBUS-DP bus, monitored by industrial computer, and control of winch, rotary table, mud pump, and automatic drilling is achieved. The integrated driller operation control system is all positive pressure explosion-proof and complies with API RP500 specifications. The system has functions such as tripping and traveling block position control, automatic and manual drilling control, disc brake and energy consumption brake control, rotary table speed and torque control, mud pump stroke control, electromechanical hydraulic and pneumatic PLC program control, etc. Traveling block anti-collision control system This system can achieve automatic control of the running position of the traveling block, preventing accidents of collision and falling of the traveling block. Electromagnetic Eddy Current Brake Control System This system is used to control the braking torque of the electromagnetic eddy current brake device and achieve smooth lowering of the traveling block. Integrated instrument control system Through on-site sensors, encoders, transmitters, and other collection units, various drilling parameters are sent to the PLC for calculation and processing. The drilling parameters such as suspended weight, drilling pressure, well depth, mechanical drilling speed, rotary table speed, rotary table torque, pump stroke, pump pressure, mud pool level, outlet return volume, total pump stroke, and the position of the traveling block, ton/kilometer, and other derived parameters are displayed on the touch screen, industrial computer, and remote terminal. Medium and low voltage switchgear We can provide various low-voltage switchgear and medium voltage switchgear that comply with NEMA and IEC standards(400V～10kV)。 The AC motor control center (MCC) of the drilling rig can control the AC motors in areas such as the drilling floor, mud pump room, mud circulation area, air compressor room, oil tank area, and water tank area, and provide well site lighting and living power supply. According to different capacities, the system can adopt direct start and soft start methods respectively. |
