AC Ice Protection Heaters Upstream of HVDC Power Conversion

The patent replaces the mechanical/thermal system of using hot bleed air from engines with an electrical heating system. Electrical heaters are powered directly from the aircraft's electrical system, eliminating the need to route and condition hot air through ducts and valves. This substitution reduces energy loss by directly converting electrical energy to heat at the required locations without the inefficiencies of air heating, compression, and distribution systems.

The patent applies preliminary action by connecting the ice protection heaters to the AC feeders upstream of the primary electrical converter. This allows the heaters to receive power directly from the generator through the AC feeders before the power needs to be converted to DC for the main aircraft electrical system. By taking power at the AC stage where the heaters are located, the system avoids the energy losses associated with converting AC to DC and then back to AC or using DC-DC conversion, thereby minimizing power loss while maintaining manageable connection complexity through standardized electrical interfaces.

The patent extracts the ice protection heating function from the main DC power distribution system and connects it directly to the AC power feeders. This separation allows the ice protection system to operate independently with its own dedicated power source, eliminating the need for multiple conversion steps between AC and DC systems. The extraction of this function reduces conversion efficiency losses while maintaining power distribution flexibility through direct AC connection and independent control of the heating elements.