Research On Integration Of 18kW Doubly Salient Electro-magnet Starter And Generator System

As the altitude and speed of aircraft is on the rise, the starter and generator system of aircraft will be brushless, high-speed and high power density in the future. The Double Salient Electro- Magnetic Motor (DSEM) with the characters of simple structure, high reliability and flexible control is a new type of brushless machine.When the rectifier is connected with the three phase winds of DSEM,the system of generator is very simple,which can output the required DC voltage only just by changing the excting current.DSEM will be one of the best choice for the brushless starter and generator system in the aircraft in the future.In orde to upgrade one indigenous starter and generator system of aeronautic application by increasing its capacity and using brushless technology, we designed a Doubly Salient Electric- Magnetic starter and generator system.The history and trendency of starter and generator system of aircraft is firstly introduced in the paper,then the tructural features, mathematical model and working principle of DSEM are analysised.The principle of the inductance,flux linkage and EMF of DSEM in the no-load and load are given by using ANSOFT software.For reducing the size and weight of the whole system, the hardware has been made integral design for the starter system and the generator system.When DSEM used as starter machine, the whole system is controlled by a digital circuit of DSP.According to the speed of motor, DSEM is worked in the Standard Angle Control Mode or the Advanced Angle Control Mode during this period. When DSEM used as generator machine, the whole system is controlled by an analog circuit.The voltage regulator uses the control strategy of double-loop of voltage negative feedback and the asymmetrical half-bridge topology is used in excitation current electrocircuit, which made sure that the voltage regulator has good steady-state performance and dynamic performance.After the system was completely designed, we firstly made some experiments of starter and generator on the ground, and the results met our expectations finely.Finally we successfully carried out the cold and hot start test of the aircraft engine, which was helpful for the further research.