模块式动态地层测试器井下大功率电机供电系统设计

The Power Supply System Designing for Underground High-power Motor of Formation Dynamics Tester(FDT)

模块式动态地层测试器井下电机工作特点是电流大,工作状态会突变,电机工作状态的变化容易引发仪器发生故障。通过遥传建立的电源数据反馈,将地面程控电源和井下50V电源有机结合,保障井下50V电源负载变化时电机能稳定工作在50V电压下;井下电源保护电路以及地面程控电源的自动调节系统保证井下50V电源输出电压急剧升高时开关导通,通过减少地面程控电源电压的输出以及加大井下电流2个手段保证50V电压输出至可控的范围内。大功率供电系统方案已经成功应用在模块式动态地层测试系统中,试验和测试表明,该设计完全满足井下大功率电机供电的需求。

Underground motors of FDT （Formation Dynamics Tester） require high currents and abrupt working-status-change adaptability. Therefore, regular three-terminal regulator circuit has these limitations. Abrupt changes of motor status will bring dramatic changes in system power supply, which causes not only motor and tool failure, but also potential damages for both circuits and motor. A locked-loop control system that combines both surface and underground circuits adopts a designing approach that uses both voltage adjustment and transient over-voltage protection designing, which guarantees the reliability of both underground circuits and motor, and therefore controls the supply power within a proper range through reducing the output voltage of the surface power and enhancing the underground power. The power signal feedback circuit set up through wireline tele-transmission system makes the surface programmed power and underground power （50 V） combine together so as to keep the motor stably working at 50 V when the underground power suddenly changes. The underground power protection circuit and auto-adjusting system of the surface programmed power keep the switch on even when the output voltage of the underground power （50 V） abrubtly goes up.