Opportunities and challenges of brushless evolution for aircraft low-voltage DC generator system

The Low-Voltage DC (LVDC) generator system is widely used in aircrafts as the primary or auxiliary power system. Recent technological developments in the aircraft electrical power system have promoted the feasibility of brushless evolution for the LVDC power system. This paper systematically elucidates the necessity of the brushless evolution for the LVDC system. The comparative studies between the brushless Starter Generator (SG) system with the doubly salient SG system as the representative and the brushed SG system are conducted in terms of the system architecture and weight, maintainability and operation performance. Accompanied by the opportunities of the brushless evolution for the aircraft LVDC SG, so have the problems and challenges of further development and application of the brushless LVDC SG emerged. These challenges and corresponding key technologies are analyzed and the development tendency is elucidated. A 9 kW brushless LVDC SG system based on the doubly salient electromagnetic machine is developed and the tests of the SG system connected with an aircraft turboshaft engine are conducted. •Brushless evolution is a trend of the aircraft low-voltage DC generator system.•The brushed and brushless starter generator systems are systematically compared.•The brushless starter generator has controllable torque and higher reliability.•The problems and challenges of the brushless evolution are elucidated.•A 9 kW brushless starter generator system has been developed and verified.