Open magnetic power inductor
Product features: density design, small size, low cost, high inductance DCR and high tilt angle stability under rated current. Product application: personal computer battery power equipment DC power circuit
With the continuous progress of key devices in the power electronics field (semiconductors and magnetic devices, etc.), soft switching topologies and control methods, the power electronics industry has gradually improved, and the advantages in power quality, performance indicators and costs have become more and more obvious, and have basically replaced The original low-frequency linear power supply.
Both semiconductor switches and magnetic devices are key devices in the power electronics industry. Magnetic devices mainly play the role of energy isolation and buffering (energy storage and filtering). Magnetic devices have a direct and important impact on the efficiency of the power system and other performance indicators (temperature rise, EMI, ripple, etc.).
In the application of DC filter inductor, due to its large DC component and small AC component, open magnetic circuit inductors are often used. The biggest advantage of the open magnetic circuit inductor is its strong ability to resist DC bias, which can reduce the volume and cost of the inductor. However, open magnetic circuit inductance also has some problems in practical applications, such as difficulty in calculating inductance and DC bias, interference with diffused magnetic flux (causing electrical performance and EMI problems), and in some cases it may even be close to other surrounding devices. Field mutual coupling will cause additional eddy current loss if there are metal objects around. These disadvantages have restricted the application of open magnetic circuit inductance in certain fields.
For the calculation of the inductance and anti-saturation ability of the open magnetic circuit, there is no more accurate calculation method in the industry. In the actual design process, actual measurement is still the main focus, which causes great troubles in the product development cycle. Based on the analysis of the magnetic circuit model, combined with electromagnetic simulation software and experimental data, this paper derives the calculation formula of the inductance and anti-bias ability of the open magnetic circuit inductance. The error rate can be controlled within 10% after actual verification.
Density design, small size, low cost
High inductance value at rated current
DCR and high tilt angle have better stability
DC power supply circuit