ELECTRIC DRIVE SYSTEM

HH’s electric drive system mainly includes low-voltage electric drive system, MCC system, wellsite circuit and lighting system. Among them, the low-voltage electric drive system includes two types: AC drive (VFD) and DC drive (SCR drive).

VFD (variable frequency drive) is the key to the AC rig. The system consist of the modules such as generator control, rectifier and inverter, dynamic brake, PLC control system, MCC system, transformers, air-conditioning, etc.

The VFD system uses ABB or SIEMENS direct torque converter, with a commonly shared DC bus. It can precisely control the drawworks, mud pumps, and rotary table. Drawworks VFD speed regulation system uses closed-loop control to ensure high starting torque for the system and improves torque dynamic response at the starting stage and low-speed to realize max output torque (suspending function) of zero speed. The inverter adopts a modular structure and is interchangeable, and also has the ability to be removed and installed quickly to limit maintenance and system downtime .

The entire system uses bus communication, with several advanced functions such as data display and recording, and remote transmission, etc.

DC Drive (SCR) system consists of generator controls, SCR control cabinet, PLC control system, MCC system, transformers, air-conditioner, etc.

The DC drive (SCR) system adopts AC-SCR-DC transmission with digital or analog speed control mode to achieve the purpose of driving different DC motors with one SCR cabinet. The system has a wide input voltage range, high adjustment precision, simple commissioning and self-diagnosis function; The modular structure of the rectifier component is easy to maintain. The system is designed and installed in accordance with the relevant electrical codes. Honghua provides high-quality power cables and reasonable & reliable cable routing for rig electrical driving system.