Implementation, integration, testing and performance evaluation of compact, battery-less alternator with external regulator on diesel engine for avionics application

This paper describes the implementation, integration, testing and performance evaluation of compact and battery–less alternator for diesel engine for avionics. The key responsibility of this alternator is to generate 2.8kW power with 28V regulated power supply using alternator control unit (ACU) for various loads. The alternator has been integrated and installed on the diesel engine and further tested on dynamometer and thrust cradle with propeller combination. The alternator when used in conjunction with ACU has ability to boot strap field voltage during low speed operation. Self-excitation ability has been derived from residual magnetism in the rotor pole pieces. The alternator with ACU system has ability to self-excite and generate power even in the absence of battery voltage i.e. in battery less system or those in which the battery is not always connected to the alternator. The voltage regulation of 28V, +/- 1V achieved with ripple up to 1.0V, which is well within limit. Using suitable pulley on engine, the alternator rpm has been matched for generating maximum power. Experimental setup on thrust cradle and dynamometer with resistive load was setup and performance of alternator has been established as per design requirements. Key Words: Diesel Engine Alternator, Alternator Control Unit (ACU), self-excitation, battery-less alternator