20.500.12556/DKUM-89733 Derivation of analytical expressions for fast calculation of resistance spot welding system currents The paper deals with the dynamics of a resistance spot welding system. At the core of this system is a transformer, which is powered on the primary side by a pulse-width modulated inverter and has a full-wave output rectifier on the secondary side that provides a direct welding current. The entire system is nonlinear, due to magnetic hysteresis and electronics. The electronics prevent the current from flowing in all parts of the welding transformer at separate time intervals during the voltage supply period; therefore, not all the parameters affect the dynamic of currents and voltages all the time so the system is also time-variant. To design a high-performance welding system and to predict the maximum possible welding current at a specific load, it is necessary to know the welding and primary currents. The leakage inductances of the system can reduce the maximum welding current significantly at higher frequencies and the same load. There are several methods to determine these currents, each with its drawbacks. Measurements are time-consuming, using professional software is expensive and requires time to learn and free open-source software has many limitations and does not guarantee the correctness of the results. The article presents a new, fourth option—a theoretical derivation of analytical expressions that facilitate straightforward and rapid calculation of the welding and primary currents of the resistance spot welding system with symmetrical secondary branches. The derivation of the mathematical expressions is based on the equivalent circuits that describe the system in different operating states. The results of the numerical simulations confirmed the derived expressions completely. DC–DC converters pulse width modulation (PWM) welding transformers center-tapped transformers full-wave rectifier resistance spot welding (RSW) leakage inductance analytical modeling time-variant system equivalent circuit pretvorniki transformerji analitično modeliranje true false true MDPI Angleški jezik Slovenski jezik https://www.mdpi.com/journal/mathematics © 2024 by the authors Članek v reviji 2024-08-08 12:12:11 2024-08-08 12:12:12 2026-01-14 12:50:26 0000-00-00 00:00:00 2024 0 0 25 str. no. 2, [Article no.] 2454 Vol. 12 Aug. 2024 0000-00-00 Zaloznikova Objavljeno NiDoloceno 2024-07-12 2024-08-05 2024-08-07 621.3 203923715 10.3390/math12162454 2227-7390 mathematics-12-02454-v2.pdf mathematics-12-02454-v2.pdf 1 DB7EC7EBF4B840BE31BB95E12C0C9BCD 4d9e69a4474ed4334f43adc63638df4458d3eaf3cbcc50ce21e082e861c50788 59e3fe0c-556f-11ef-b25f-00155d000105 https://dk.um.si/Dokument.php?lang=slv&id=182145 https://www.mdpi.com/2227-7390/12/16/2454 0 36ea829d-f13f-11f0-8a93-00155d580e02 https://dk.um.si/Dokument.php?lang=slv&id=202003 Fakulteta za elektrotehniko, računalništvo in informatiko 0 0 0