How energy flow through a DRSSTC?

[VNTC]

As we know in original Tesla coil energy were pumped  into a Tesla coil by a very simple way(1 time of high voltage charged in to capacitor C1 for a bang)
Image 1
This schematic with parameters base on a real coil(my test coil)a half bridge running on 340Vbus can generate square wave +-170V amplitude.
Static primary resonance frequency5.6u H;80nF is 237.8kHz
Static secondary resonance frequency 27mH;15pF is 250kHz
In DRSSTC square wave applies in to the serial resonance L1C1 as in this schematic, easy to measure primary current but hard to calculate the power was pump into this resonance circuit. Very simple ,the result of simulation will gives the result of this question.

Image 2:green region is power in 140us duration, yellow region is output power maintain 10us after power in cut-off. About48kw peak to peak for power in and the same for power out they present only onside of polarities because it will be supply power or consumption power only.
 To find energy in the spark we should find RMS power first and multiple with duration. Look at the yellow wave it’s amplitude is 24kw peak/1.41=17.02kwRMS
17020*140/1000000=2.38joules

Image 3 red wave is power in at L1(350Kw peak)and purple wave  is power out inside  L2(200Kw peak).They are combine reactance power 80% and real power  20% that bigger ingredients were a transportation. Their wave combine 2 side of polarities but one side higher than another.( if they are symmetric wave they do not transportations anything as the case primary power without L2C2)

Image 4 primary current.( in 10us duration, easier for looking their period)

Image 5 secondary current. ( in 10us duration, easier for looking their period)
Final running frequency is 250kHz, this value find out by looking  at image 4 and image 5 we can see they have the same period  include the period of signal of square wave =4us. Moreover decrease load resistor from 220k became 120k make power out  always  grow up, means this coil run at good tuning.
Image 6 it’s great primary current is stable and slightly increased.


I have run a lot of simulations that some of them primary current  overcomes 350 Apk but output power is worse. If anyone discovers a case other than better performance, please upload to share to our community.

[Uspring]

Usually DRSSTCs are run with zero current switching, since that avoids hard switching issues like transients and losses in the IGBTs. The feedback mechanism to ensure that, does usually not allow to choose the running frequency. The frequency arises from the feedback and corresponds to the poles of the TC circuit. The poles aren't identical to the primary and secondary resonance frequency but lie outside of them. Supplying the coil with a fixed frequency can lead to some interesting effects, but these aren't typical for most DRSSTCs.

Also note, that the arc load, i.e. its resistance and capacitance, depends strongly on the power going into the arc and time. See e.g.: https://highvoltageforum.net/index.php?topic=117.0

That being said, a lot can be learned from models as yours.