A modular 36 kV, 24 A crowbarless dc power supply with input parallel and output series connected 500 V, 24 A dc–dc converters is employed for biasing high power radio frequency (RF) amplifiers. Control system having both feed-forward and feedback control is implemented for fine regulation of its output voltage. An optimized control strategy having unique output ripple free capability is adopted. Active redundancy is incorporated to improve the reliability of this power supply significantly. Input section and output section are independent of each other, so the variations in input line voltage and control of output voltage do not affect input and output performances of this power supply. The adopted scheme neither needs any line filter nor needs any crowbar for biasing RF amplifiers. This power supply achieves input power factor ≥ 0.97, current THD ≤ 6%, output ripple ≤ 0.25% and output voltage stability ≤ 0.4%.