Sourcing Low PD High Voltage AC Power Supplies

[waka.chi]

I'm working on a project that requires a high voltage AC power supply, but with very low partial discharge characteristics ideally suited for insulation testing and long duration stress tests on HV components. I need something in the 20kV–100kV range, with clean sine output and stable performance under varying loads.
Does anyone have recommendations on design sources, reference designs, or even specific vendors known for low PD AC supplies? I'm open to building or modifying something if there's a reliable base design. PS: my priorities are low noise, low PD, and long term reliability not necessarily compact size.
Thanks in advance!

 

[RoadRashRick]

@waka.chi
High voltage, low PD AC is a tough ask! you need a specialized gear.
Check out Phenix Technologies (or Doble/Haefely), HV Technologies, and Megger. They build test equipment specifically for this

 

[Israel duv]

I agree with @RoadRashRick , Hipotronics too, high quality, low partial discharge AC supplies
Older resonant transformer based designs can be a good starting point for rebuilding up something