一种基于双全桥的电压补偿系统

A Voltage Compensation System Based on Dual Full Bridge

核磁共振测井技术主要利用发射天线激发的射频磁场,使地层物质产生核磁共振现象来获取地层信息。此处根据核磁共振测井仪发射模块研制项目的需求,实现射频高压正弦波的发射,并针对发射电压在谐振过程中出现幅值衰减的问题,设计了一种新型的基于双全桥的反馈型电压补偿系统。该系统主要包括双全桥发射电路和电压反馈补偿两部分,其中主控芯片将实时采集的发射电压值与系统设定电压的差值作为系统误差,通过比例积分(PI)算法计算下一周期相应场效应管的导通时间;双全桥电路根据芯片计算的控制量,实时调整场效应管的导通时长,以达到将发射电压补偿至系统设定电压的目的。该系统能够将核磁共振测井仪发射电压快速可靠地补偿至系统设定电压,实现发射电压稳定输出。

The nuclear magnetic resonance logging technology mainly utilizes the radio frequency magnetic field excited by the transmitting antenna to generate nuclear magnetic resonance phenomena in the formation material to obtain formation information.It is based on the requirements of the development project of the emission module of the nuclear magnetic resonance logging tool to achieve the emission of radio frequency high-voltage sine waves.To address the issue of amplitude attenuation of the emission voltage during the resonance process,a new type of feedback voltage compensation system based on dual full bridge is designed.The system mainly consists of two parts:a dual full bridge transmission circuit and voltage feedback compensation.The main control chip takes the difference between the realtime collected transmission voltage and the system set voltage as the system error,and the conduction time of the corresponding field-effect transistor in the next cycle is calculated through the proportional integral(PI)algorithm;the dual full bridge circuit adjusts the conduction time of the field-effect transistor in real-time based on the control amount calculated by the chip,in order to compensate the emission voltage to the system set voltage.This system can quickly and reliably compensate the emission voltage of the nuclear magnetic resonance logging tool to the system set voltage,achieving stable output of the emission voltage.