随钻地层测试器中电机精密控制系统的设计与应用

Design and Application of Motor Precision Control System in the Formation Tester While Drilling

在随钻地层测试器中,电动机是随钻地层测试仪的动力核心。对预测试直流无刷电机进行高精密的控制是实现随钻地层测试中流量调控、压力可控等技术的关键,决定了整个随钻地层测试器测压功能的实现和作业质量。详细论述了电机精密控制系统硬件、软件的实现方法,以数字信号处理器TMS320F2812为控制中心,由IR2133驱动金属-氧化物半导体场效应管(MOSFET)构成的逆变器来实现直流无刷电机的高精度伺服控制,从而实现随钻测压要求的恒流抽吸技术。该设计硬件简单,功耗低,软件功能强大,集成度和精度高。大量精度测试表明,整个系统的定位精度可达1.401°,随钻地层测试仪器抽吸精度可达0.0012 mL。并且该电机控制驱动系统启动电流小,电机运行平稳可靠。

The motor is the power core of the formation testing while drilling,The high-precision control of the DC brushless motor of the prediction test is the key technology to realize the flow regulation and pressure control in the formation testing while drilling,which determines the realization of the pressure measurement function and the operation quality of the whole formation tester.In this paper,the hardware and software implementation methods of the system are discussed in detail.It uses TMS320F2812 as the control center and IR2133 drives the MOSFET power inverter to realize the high-precision servo control of the three-phase six-state SVPWM modulated brushless DC motor.Thus,the constant current pumping technology required by formation pressure measurement while drilling is realized.The design is with simple hardware,low power consumption,powerful software,high integration and high precision.After a large number of precision tests,the system′s control accuracy is up to 1.401°,suction accuracy of the instrument is up to 0.0012 mL.The starting current of the motor control drive system is small and the motor runs smoothly and reliably.