过钻杆四臂井径测井仪器中BLDC控制与驱动模块设计

Design of Sensorless BLDC Control and Drive Module Used in Through-pipe Four Independent Arm Caliper

在57mm外径限制下,过钻杆测井仪器不仅需要高可靠性、长寿命、低功耗,而且需要保障测量精度与机械强度,其设计比常规仪器要困难得多,需要优选传感器与执行器、优化机械结构。针对过钻杆四臂井径测井仪器的需求,采用无位置传感器无刷直流电机(BLDC),研制了该电机的控制驱动模块。以ARM为控制核心,采用脉冲宽度调制(PWM)、三相全桥驱动、反电动势过零检测,实现电机驱动换相、转速调节,并设计了电机电压、电机电流监控电路、行程控制,实现BLDC保护。以过钻杆四臂井径测井仪器的管理与通信单元为桥梁,实现了该模块与地面系统的双向通信。室内测试表明,四臂井径测井仪器耐温达到175℃。在地面供电与电池供电2种情况下,电机均能可靠工作,已经在现场应用37井次,取得了良好的效果。

The Through-Pipe Logging System has two logging modes which are memory logging mode and wireline logging mode.This logging system is very useful for high-angle deviated wells,extended horizontal wells,complex wells and slim-hole wells.With the limit of 57 mm outer diameter,the logging tools need not only high reliability,long life,low power consumption,but also need high measurement accuracy and mechanical strength.Therefore,the design of through-pipe logging tool is much more difficult than conventional instruments,and it is necessary to choose the sensor and actuator and optimize the mechanical structure.In order to meet the requirements of through-pipe four independent arm caliper,a brushless DC motor was used and the drive module (MCD)with ARM-based control center was designed.In addition,the pulse width modulation (PWM),three-phase full-bridge drive,and back-EMF zero-crossing detection were used in motor commutation and speed control.Meanwhile,motor voltage and current monitoring circuits were designed to protect the sensorless BLDC.As a bridge,the tool communication and control module (TCC),which is a uuniversal module used in all through-pipe logging tools,ensures the two-way communication between the MCD module and the ground system.The indoor tests show that the logging tool can work up to 175℃.In both cases of ground power and battery power,the motor works reliably.37 wells have been applied with this tools,and good results have been achieved.