S.C.R silicon control rectifier

Petroleum electric control system is generally divided into two categories, one is DC (Direct Current) equipment, which used for driving DC motor, simply SCR(silicon control rectifier)for short. Another is AC (Alternating Current)equipment, which used for driving AC frequency motor, here called VFD(Variable Frequency Drive) system.

SCR system was designed and developed by ROSSHILL company in the eighties. The oil chain drive equipment was gradually replaced by the SCR since the stable performance and easy maintenance, that bring the Oil Drilling turn to the full automation times, comparing with the current  emerging Variable frequency system, SCR has the following advantages:
  1. Mature Technology SCR equipment has been tested in the field of extreme environment and performed well.

  2. Easy Maintenance SCR came to being earlier, has been used in wider area for some common problems, generally, engineers with longer  working experience can deal with it, for the complex trouble, need professional serviceman to work out it. 

  3. Competitive Price    The spare parts are available in many district, and could be used universally.

  4. AC control system   Alternating Current electric control system is the newly-developing drilling Rig Electric Drive System in recent years. 

  5. good feedback   It has earned the good feedback from user for the better performance, higher efficiency and easy operation.

Compare with the SCR system, AC electric control system have the following advantages:

Motor Control Mode

Since the Siemens or ABB  frequency converter is adopted to drive Alternating Current frequency motor. Having better working accuracy and stability, especially on winch control, it can easily be lifted and laid down and easy to use, so greatly meet the use on the drilling site, enhancing the efficiency of drilling, which higher than AC system.

Accurate control

VFD system combined with PLC control and Speed measuring machine Variable frequency motor side mounted. These functions make the motor control  achieved the closed-loop control and Run more smoothly, also the running speed can be controlled according to the actual requirement.

Hover Function of winch

Winch is the important part in the rig components, due to the characteristic of the motor itself,the down could not control by motor, but by its own suspension and auxiliary brake system to participate in the control. since many operating process, that have high request on the driller. Who having proficiency on operation and problem solved capability, since there is prone to happen drilling accidents. However, the motor driven variable frequency system with the hover function, made the winch could stop under control by making the handle which control the motor of winch to return to zero status and without other auxiliary brake function. Which make the drill’s work simple, safe and reliable. The difference of DC and AC system in the control of the winch, such as the operation difference between manual gear car and automatic transmission when operating the car.

Highly Integration

   With the Frequency conversion rig widely used, according to the requirement of customers, the drilling and mining and other related data could be collected by PLC integrated into industrial control computer not by a separate instrument, so the cost could be saved a lot also provide the convenience on equipment install, moving and maintenance.


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