an alternator / inverter system for use with a portable generator which includes a voltage regulation system . the alternator / inverter incorporates a pair of permanent magnet generators , a pair of active rectifier circuits , a pair of dc bus capacitors and a pair of h - bridge inverters , forming two distinct alternator / inverter sections . each alternator / inverter section provides a 120 vac output , and a 240 vac output is formed between the two alternator / inverters sections . the voltage regulation system is formed from a pair of voltage regulation circuits that are associated with each alternator / inverter section . the circuits monitor the dc bus voltage of each alternator / inverter and determine the dc losses resulting from electrical cabling coupling the alternator / inverters to external loads , as well as the h - bridge inverters . a microcomputer or an analog device controls the rectifiers of each to perform “ v + ir ” compensation based on the sensed dc bus voltage of each alternator / inverter section .