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Magnetically controlled reactors (MCRs) are widely used as reactive power compensation equipment owing to their favorable properties of smoothly adjusting their inductance value through dc bias. However, the dc bias and the rotational magnetization at corner and T-joint areas make the cores of MCRs saturated, resulting in high magnetostriction and vibration. Thus, the electromagnetic vibration analysis of MCRs must consider the vector hysteretic magnetostriction effect. In this article, a vector hysteretic magnetostriction model of silicon steel is proposed by combining the quadratic domain rotation model with the vector inverse Jiles–Atherton model firstly. Then, based on the measured magnetization and magnetostrictive characteristics curves of silicon steel, the model’s parameters are optimized by velocity controllable particle swarm optimization (VCPSO). Finally, the vector hysteretic magnetostriction model is combined with the finite element method (FEM) to simulate the vector vibration characteristics of MCR under dc bias. The simulation results show that the vector property of electromagnetic vibration and magnetic field at the T-joint area is higher than that at other areas. And the MCR vibration test results are consistent with the simulation results, which verify the accuracy of the proposed model in simulating electromagnetic vibration. [ABSTRACT FROM AUTHOR]

In order to study and analyze the rotating magnetic properties for nanocrystalline material, an improved 2-D high-frequency magnetic properties tester with step-shaped excitation windings and composite sensing structure is designed and modeled. Magnetic concentration and core poles optimization are performed in 2-D tester construction, which can generate relatively uniform and strong magnetic field in the testing area. By using the composite sensing structure of sensing coil combined with needle probe method, $B$ and $H$ signals can accurately be detected. Meanwhile, feedback control algorithm and harmonic compensation are established to obtain the desired magnetization curves and improve the measurement precision. [ABSTRACT FROM AUTHOR]

A new closed-loop magnetic current sensor is presented in this paper. The sensor consists of two toroidal magnetic cores. One core works in fluxgate principle for the measurement of dc and low-frequency ac, and the other one is used as a current transformer for higher frequency application. Based on the simulation results, a prototype was designed, and the test results have a good agreement with the simulation results. The closed-loop configuration with a magnetic core and a feedback winding in the sensor improved the sensitivity of the sensor, eliminated the offset and drift related to temperature, and greatly reduced the error caused by magnetic hysteresis phenomenon. It can measure currents up to 20 A, with an accuracy of 0.5%, and a 50 kHz small signal bandwidth. [ABSTRACT FROM PUBLISHER]