HIL emulation of all-electric UAV power systems

Hardware-in-the-loop (HIL) techniques are used to examine the start-up sequence for an all-electric UAV system powered by a two-spool gas engine with embedded electrical generators on both spools. Start-up begins with the auxiliary power unit charging the high voltage DC bus to enable the high pressure spool switched reluctance starter/generator (SRSG) to spin the gas engine to ground idle speed and ends with the SRSG and the low pressure spool fault-tolerant permanent magnet generator being connected in parallel. HIL methods are used to emulate the behaviour of the gas engine and the loads. The HIL elements compliment the `real' electrical generators and bus system. The start-up sequence is demonstrated on a purpose-built laboratory system to examine system interactions and the feasibility of the operating routine.