# Resonannt frequency of resonant current converter DC/AC

I have to work with this topology of resonant current converter, and I want to clarify some points:

• T1 is a transformer that I should specify to designer
• LT is a tuning inductance
• T2 is a transformer made with a wire (one winding in primary) passing through different magnetic cores of different devices. Each device has its own number of winding. All devices use a rectifier and a voltage refrence to made a DC voltage source.

Is it correct to simplify the circuit as I did with one transformer passing through the one equivalent magnetic core to provide equivalent DC voltage source?

The second point, is related to the resonant frequency. What is the equivalent impedance seen on the primary side of the transformer T1? Some article simplify the circuit as bellow: Is this correct to consider Lp (primary inductance with secondary open) since the secondary load of T1 is LT with a wire loop. This simplification doesn't take into account leakage inductances.

• Don't do the math - use a simulator and do the job properly. The math gets too tricky as things inter-mingle. Micro-cap 12 is now fully functional with all libraries and free (as a bird). Apr 7, 2020 at 15:12
• @Andyaka Thank's for the reply. My system is too complicated to be simulated. Even if I make it more simple, simulating with all component tolerance will get worse. I have done some simulation but also I end up with too much differences comparing to the measurement. I don't have all the models but I will check the micro-cap
– hiak
Apr 8, 2020 at 7:59
• If it's too complex for simulation then it's massively too complex for math. Apr 8, 2020 at 8:56
• What I mean by complex is that the system has many components and different models of transformer are missing, because they are "home" made. In addition simulate the whole system requests lot of resources. I have try some simulations using LTSpice and I end up with differences comparing to the measurements. What I want is to know what should I consider to calculate resonance and currents. The current form is quite simple, since it is pseudo sinusoidal. Frequency, RMS and peak seems different from the measured values.
– hiak
Apr 8, 2020 at 15:53
• You have a self-admitted complex system and a scrap or two of circuit ideas posted in your question body and you are asking for formulas. Sorry, I can't help you here because you are just not being specific enough. My route would be simulate (not using LTSpice) and learn from the real measurements where the models need to improve and get the sim working like a typical scenario. If you have a more focused question on a particular circuit then ask it. Apr 8, 2020 at 15:59