Power supply for very high insulation requirements in IGBT gate-drives

A power supply concept for very high insulation requirements in gate-drives has been developed. The power supply concept is described, layout decisions are explained and simulations and measurements are presented. The power supply has been tested and is already operating in different industrial products. Very high efficiencies of 80% and power levels of 10 W have been achieved over a wide input voltage range. The zero voltage switching, multiresonant converter ZVS-MRC concept with the control concept used here, can deliver multiple output voltages with few components. Together with the high switching frequency and an optimized transformer construction, the concept used is well suited for integration into the gate drives of modern semiconductor switches like IGBTs or IGCTs. With a range of 20 US$, the total cost are very low. Currently they are used for IGBT converters for up to 4500 V operation voltage, but they can be adapted easily to higher power and different insulation voltage levels.