Transient analysis and optimization of output LC filters of switching power supplies

The article presents the results of a study focused on the analysis of transient processes in switching power supplies and the optimization of output LC filter parameters. The relevance of the study is driven by the widespread integration of switching converters into modern equipment, which necessitates a detailed investigation of transients. During these processes, short-term overvoltages (spikes) occur during power-on and power-off cycles, potentially leading to device failure. Conventional filter calculations based on steady-state operation do not always account for dynamic overloads, requiring the use of modern computer-aided design (CAD) tools to refine device characteristics. The aim of the work is to develop a methodology for modeling the electrical modes of power supply units within the Altium Designer environment to select optimal LC filter component values that ensure target output voltage ripple levels and eliminate hazardous transients. During the study, numerical experiments based on circuit simulation methods were conducted. The proposed approach is centered on a comprehensive analysis of transient characteristics while varying the parameters of the filter's reactive elements. The simulation results yielded a family of graphs reflecting the dependence of overvoltage amplitude and output voltage ripple peak-to-peak values on inductance and capacitance ratings. Consequently, optimal LC filter values for the power supply board were determined, ensuring a smooth rise of the output voltage (without spikes) during power-up. The practical significance of the work lies in the applicability of the presented methodology at the design stage to enhance the reliability of electronic equipment and reduce prototype debugging time. The obtained data confirm the effectiveness of using Altium Designer’s built-in simulation tools to prevent emergency operating modes in power supplies.

1. Shabalin N.G., Feoktistov V.P., Inkov Yu.M. Inductive‑capacitive pulse DC voltage converters. Elektrotekhnika. 2011;(8):33–36. (In Russ.).

2. Nguyen D.H. Diagnosis of faults in analog radio electronic devices by simulated annealing method. Mechatronics, Automation, and Robotics. 2024;(13):172–174. (In Russ.). https://doi.org/10.26160/2541-8637-2024-13-172-174

3. Dmitrikov V.F., Samylin I.N., Shushpanov D.V., et al. Investigations of output voltage ripples of transistor buck converter. Physics of Wave Processes and Radio Systems. 2007;10(2):86–93. (In Russ.).

4. Tsarenko A.I., Seriogin D.A. Circuitry development of closed-input DC/DC converters. Bulletin of Moscow Power Engineering Institute. 2008;(4):60–65. (In Russ.).

5. Fogel A.L., Gulyaev V.V. Pulse voltage converters for secondary power supplies. Railway Transport. 2025;(12):36–37. (In Russ.).

6. Baregamyan G., Margaryan V. Selection of parameters for an LC filter in an inverter with pulse‑width modulation and sinusoidal output voltage. Power Electronics. 2011;1(29):50–56. (In Russ.).

7. Golubev V.V. Calculation and optimization of the LC-filter of the pulse converter of a AC voltage. Technical Electrodynamics. 2012;(1):33–37. (In Ukrainian).

8. Erickson R.W., Maksimović D. Fundamentals of Power Electronics. Cham: Springer; 2020. 1084 p.

9. Kazimierczuk M.K. Pulse-width Modulated DC-DC Power Converters. Chichester: John Wiley & Sons; 2015. 960 p.

10. Mohan N., Undeland T.M., Robbins W.P. Power Electronics: Converters, Applications, and Design. Hoboken: John Wiley & Sons; 2003. 802 p.

11. Rashid M.H. Power Electronics: Devices, Circuits, and Applications. Pearson; 2013. 1024 p.