Research on Prediction Method for Radiated Interference of Flyback Converter Considering Long Vertical Cable Arrangement
YuCheng Ding, YunHao Jiang, Yi TianIntroduction:
Conventional radiated EMI prediction models and electromagnetic simulations are computationally expensive and rarely consider vertically routed cable configurations. A radiated EMI prediction model for flyback converters with long, vertically arranged cables is proposed, aiming to provide theoretical support and engineering guidance for the analysis and suppression of radiated EMI.
Method:
This paper proposes a theoretical model for predicting radiated emissions from a flyback converter based on port equivalence and dipole antenna theory. Key model parameters are experimentally extracted to predict the maximum radiated electric field strength. The model is validated using a simplified three-dimensional electromagnetic simulation model, and experimental measurements were carried out in a semi-anechoic chamber in accordance with the vertically routed cable requirements of GB/T 9254.1-2021.
Result:
By comparing the simulation, experimental measurements, and theoretical predictions, the results show that the proposed prediction model is effective and can accurately reflect the radiated emissions at the peak positions, with a prediction error within 15 dB. The error of the simulation model is within 10 dB
Discussion:
Compared with the traditional horizontal layout, the vertical arrangement of input/output cables saves horizontal space and alleviates wiring congestion. It is suitable for applications with vertically elongated installation spaces or compact and orderly wiring requirements, such as floor emergency lighting and compact power electronic systems with constrained installation space. The radiation calculation prediction model proposed in this paper does not rely on an anechoic chamber environment. The simulation prediction model is simple and features low computational cost.
Conclusion:
Compared with existing radiated emission prediction methods for switching power supplies, the proposed radiation prediction model based on port equivalence is applicable to application scenarios where the power supply cables are vertically arranged. It provides a practical approach for the analysis and design optimization of radiated interference in switching power supplies.