Optimization Design Of Hall Sensor Magnetic System

With the continuous development of information technology, Hall current sensor has become one of the first part of information collections. Meanwhile, Hall current sensor which is widely used continuously develop to the direction of the large range, high sensitivity, and lower price.In this paper, we take three parts of hall current sensor(the hall device, electronic processing circuit, magnetic system)as research object, and analyze the basic working principle of the Hall current sensor, then design the open-loop Hall current sensor and closed-loop Hall current sensor. Nowadays the price of Hall sensor is relatively high and the magnetic system is an important part of Hall sensor that its size and weight accounts for a large proportion. As the first part of the signal conversion, the reasonable design of the magnetic system directly affects the performance of the sensor. Therefore when designing the three parts of the Hall current sensor, in order to increase the range and sensitivity of Hall sensor, we detailed study and optimize the magnetic system of Hall sensor.Firstly, in the magnetic system design optimization, we detailed study the characteristics of the core material. According to the different operating characteristics of the open-loop and closed-loop Hall current sensor, different magnetic core materials are selected. Based on the analysis of the magnetic circuit, open-loop and closed-loop Hall sensor equivalent magnetic circuits are set up. Then using the Maxwell Ansoft magnetic simulation software to design and optimize the geometry of the system and analyze the magnetic field amplification of the magnetic core with different ratio of the length to width and the narrowed shape of the core. Through the derivation and simulation, the effect of the existence of the Hall sensor air gap on the magnetic system is detailed studied and further analysis the effect of air gap length and air gap cross section on system range and sensitivity of the Hall sensor and the winding loss of the closed-loop Hall sensor. In closed-loop Hall current sensor, we analysis the effect of the distribution and the location of the primary winding conductor on the magnetic saturation characteristics of the system. The theory is verified by simulation and the open-loop and closed-loop Hall current sensor are made. Both of them pass the experimental measurements.In the optimum design of the Hall current sensor’s magnetic system, the paper applies the distribution of the air gap geometry to further optimize the structure of the Hall sensor and get four different magnetic core structure solutions. These four systems have its own advantages and disadvantages, but can apply in different occasions, and can also be applied to the Hall sensor magnetic system with dual Hall device. These four magnetic core structures had been verified by simulation.