Nonlinear behavior mechanism and modeling method of wound SMD inductor

Abstract

In the actual use process, the characteristics of the wire‐wound power inductor will change. On the one hand, the DC bias will fluctuate because the working current of the wire‐wound power inductor is not constant; on the other hand, there is a variable magnetic field, which, according to the principle of electromagnetic, affects structural size, core permeability, and flux density, both of which affect the amount of inductance. As a result, this research examines the wire‐wound SMD inductor's nonlinear behavior and modeling approach. Under the condition of zero bias at normal temperature, the static model is determined by simulating Y parameters and comparing its main performance parameters. The influence factors of temperature and DC bias are studied. The nonlinear model circuit is written in Verilog‐A format, and the inductor‐current curve is fitted by polynomial. The dynamic model is verified by ADS and compared with the test data. SWPA series power inductor measurement data from Sunlord is used to verify the validation of the model proposed in this paper. The Y parameter and performance index under zero DC bias at room temperature, inductance characteristics under different currents and inductance characteristics under different temperatures were compared respectively. From the comparison results, it can be concluded that, The fitting accuracy of the model is good in the frequency range of 100 KHz ~ 100 MHz, DC bias range of 0 ~ 0.28 A, and different temperatures (−40, 25, 125°C).

Current Sensor Fault-Tolerant Control Strategy for Speed-Sensorless Control of Induction Motors Based on Sequential Probability Ratio Test

“…This means that under normal circumstances, only the currents of two phases are sampled by current sensors. However, if one of the current sensors malfunctions, the measured i sα and i sβ of the IM provided to the EKF by the remaining current sensor are inaccurate, leading to the inability of the EKF to estimate the IM speed accurately [23][24][25][26][27][28][29][30][31]. Based on the idea of coordinate translation, this paper proposes a double-cascading second-order generalized integrator (DSOGI) to correct the fault phase current and obtain the required measurement information for high-accuracy motor speed estimation in the α-β coordinate system.…”

“…Similarly, detecting an anomaly of the i sa signal by the SPEKF indicates that the current sensor of B-phase is faulty. If the current sensor of A-phase goes wrong, a fault-free signal i sa can be obtained using (26), and the flag bit switches to 1: Flag A = 1. If the current sensor of B-phase goes wrong, a fault-free signal i sa can be obtained using (25), and the flag bit switches to 1: Flag B = 1.…”

Nonlinear Modeling and Control Strategy Based on Type-II T-S Fuzzy in Bi-Directional DC-AC Converter

“…Paper [14] proposed a single-sensor current balancing method with less complexity and a smaller volume by analyzing the total current after interleaving, and utilizing the nonlinear behavior of inductors in interleaved DC-DC converters. In [15], the characteristics of wire-wound power inductors were investigated. The static model was determined, the factors affecting the temperature and DC bias were investigated, the inductance current curves were fitted by polynomials and, finally, the inductance characteristics at different currents as well as the inductance characteristics at different temperatures were obtained.…”