Variable frequency AC input BLDC low loss control technology for aviation pump

AC-DC-AC topology is widely used in the control system of three-phase variable frequency AC input BLDC for aviation pumps. In order to meet the requirements of high power factor and low harmonic at the grid side, AC-DC-AC topology uses PWM rectifier and PWM inverter to form a back-to-back system, namely dual PWM speed regulation system. When the system works, the rectifier side and inverter side work at high switching frequency at the same time, and the power device loss includes a large number of switching losses. In order to reduce the switching loss of power devices, this paper applies the PAM control method to the AC-DC-AC system, and controls the DC output voltage of the rectifier through BLDC speed feedback. In this paper, the power loss of the driver controlled by PWM and PAM is compared under two working conditions of the pump motor. The results show that PAM control can significantly reduce the power loss of the driver.