Research Of72V Doubly Salient Electro-Magnet Starting System

With the rapid development of power electronics and motor control technology, low-voltagebrushless DC starting systems become realistic to replace the brush DC starting and generating system,which is widely used in active aircraft. Brushless DC systems use electronic commutation to replacemechanical commutation to avoid the carbon brush wear, the cooling problems and the high altitudecommutation difficulty of brush systems.Firstly, this paper elaborates the significance of brushless transformation for the starter/generatorsystems. Then, the development and research status of the domestic and foreign brushlessstarter/generator systems is introduced, especially that of the domestic development of doubly salientstarter/generator systems.The Doubly Salient Electro-Magnetic Motor (DSEM) is a new kind of doubly salient motors, whichhas high reliability, high power density and flexible controlling method. The structure of three-phase12/8pole DSEM is analyzed and the double rotor structure is described in detail, in addition theoutput torque of DSEM is derived under linear inductor model. To find the optimal advanced angle,the DSEM is simulated using the finite element analysis software Ansoft. Torques in differentadvanced angles and in different current limits are compared and the optimal advanced angles areconcluded.Both the hardware and software of72V starting system which uses the DSEM as its motor areintroduced in detail. The hardware includes the controlling cuicuit and the high power converter. Thesoftware includes the standard angle controlling process and the advanced angle controlling process.After carrying out the simulated torque starting experiment, more than one hundred times of coldand hot starting test is successfully finished with the real aircraft engine, proving that the startingsystem has not only sufficient capacity but also high reliability.