Research On Design Of DC Sensor Based On Magnetic Potential Self-balance And Feedback Compensation

The accuracy and reliability of the large DC measurement devices have great effect on the electrochemistry, electrometal and electric power factory. The classical large DC sensor based on single sensing theory lack of reliable measuring accuracy for theories'shortage.The DC sensing theory and method based on magnetic potential self-balance and feedback compensation are studied in this paper. The theory is based on the combination of open loop and closed loop measurement theories. The innovative and unique points are as follows. The method of magnetic potential self-balance is put forward applying the characteristic of iron core's rectangular magnetization curve. The different of ampere-turn is measured by the reasonable design of reactor's iron core. The feedback compensation system is a closed loop without high gain. This method not only has found closed loop compensation but also has avoided the high power drive and oscillation problems induced by high gain of closed loop system.Firstly, the magnetic flow change of magnetic potential self-balance cores, the current wave of self-balance circuit and wave equation of the current were researched based on the basic principles about traditional DC sensor and two-way magnetic magnifier. Then, the detection circuit was researched in theory based on the analysis of the detection cores'magnetic flow change, and the expression of detection sensitivity was given. Several measures that can improve detection sensitivity were put forward and proved in experiments. Lastly, a prototype machine was designed. Experiments confirm the validity of the new DC sensing theory.The new style DC sensor based on advanced principle is easy to design and realize. The success of this project's study has not only filled up the blank of this region in domestic and overseas but also established the theory and technical foundation for the new generation of DC sensor.