Dealing with varying frequency pulsed load on a power supply

[state_of_flux]

I have designed a resonant LCC converter that has two output voltages, -3KV @ 200mA and -6kV @ 10mA giving a total load power of 660W. It works fine under a constant load.

The application is for a travelling wave tube, which is an RF amplifier. Depending on the mode of operation, the load can be pulsed/triggered on and off at various frequencies and duty cycles. For example, one scheme may be 100Hz pulse repetition frequency with 50% duty cycle at one extreme, and 1% duty cycle at a pulse repetition frequency of 100kHz at the other extreme. This is pulse widths of 5ms and 100ns respectively.

This is where I am struggling to comprehend how to deal with this output pulsing. I have been recommended to use a MOSFET linear post regulator on the high voltage output to compensate for the output pulsing but cannot for the life of me find an example circuit on the web.

The load pulsing causes transients from full load (>200mA) to substantially no load, (0A). As many will know resonant converters transient response is probably not fast enough to deal with this output pulsing while keeping the output voltage in regulation.

Does anyone please have any advice on how this can be handled, and point me in the right direction to some documents for me to study. It would be greatly appreciated.

Output voltage ripple allowed around the 6kV output is approximately 20Vpk-pk.