Hello all,
I often see the flyback is used in high voltage, low current applications such as for CRT monitors and the like. I was wondering, what are the general improvements that can be made to a flyback converter to make it better suitable for high voltages, but at more significant currents? As a reference, my application requires around 200mA.
I see some variations such as the two-switch flyback converter (I like this one!), the active clamp flyback converter, etc, all of which can achieve very high power densities, especially if using new semiconductor devices.
One of the main drawbacks of flyback is that energy is stored in the transformer, and therefore must be sized for this. Whereas in other topologies since there is theoretically no actual storage within the transformer, it can be smaller and more compact. I have came across this patent https://patents.google.com/patent/US5796595 which is an interleaved, active clamped flyback converter. I assume (?) that the reason for this is that now energy transfer to the secondary side occurs at twice the rate it did originally, due to the 180 degree phase shift between the two flyback switches. But I don't see this being appropriate for HV, since the outputs are connected in parallel and typically we see HV outputs generated by multiple stacks of multipliers connected in series.
Maybe I do not have a "question", but I am really interested in hearing people's thoughts on how to improve the flyback converter to generate high voltages. Is there a way to deal with the high parasitic capacitances, in the hardware? What are the best ways to wind a transformer for high voltage to minimize these capacitances? Literally anything you can think of to contribute to this thread will surely help me with my endeavour to produce a highly efficient, compact flyback.
Specification: 5kV and 2kV outputs @ 20mA, 180mA. I have tried very hard to design a resonant LCC converter but have found it too difficult so I am attempting to make a start on a more simple, preferably fixed frequency flyback that I can get a working prototype of ASAP.
Any and all advice appreciated!
I often see the flyback is used in high voltage, low current applications such as for CRT monitors and the like. I was wondering, what are the general improvements that can be made to a flyback converter to make it better suitable for high voltages, but at more significant currents? As a reference, my application requires around 200mA.
I see some variations such as the two-switch flyback converter (I like this one!), the active clamp flyback converter, etc, all of which can achieve very high power densities, especially if using new semiconductor devices.
One of the main drawbacks of flyback is that energy is stored in the transformer, and therefore must be sized for this. Whereas in other topologies since there is theoretically no actual storage within the transformer, it can be smaller and more compact. I have came across this patent https://patents.google.com/patent/US5796595 which is an interleaved, active clamped flyback converter. I assume (?) that the reason for this is that now energy transfer to the secondary side occurs at twice the rate it did originally, due to the 180 degree phase shift between the two flyback switches. But I don't see this being appropriate for HV, since the outputs are connected in parallel and typically we see HV outputs generated by multiple stacks of multipliers connected in series.
Maybe I do not have a "question", but I am really interested in hearing people's thoughts on how to improve the flyback converter to generate high voltages. Is there a way to deal with the high parasitic capacitances, in the hardware? What are the best ways to wind a transformer for high voltage to minimize these capacitances? Literally anything you can think of to contribute to this thread will surely help me with my endeavour to produce a highly efficient, compact flyback.
Specification: 5kV and 2kV outputs @ 20mA, 180mA. I have tried very hard to design a resonant LCC converter but have found it too difficult so I am attempting to make a start on a more simple, preferably fixed frequency flyback that I can get a working prototype of ASAP.
Any and all advice appreciated!