A CLOSED-LOOP V/f Control Strategy Based on Instantaneous Power Feedback

Affected by the working environment and flight state of electric VTOL aircraft, the starting torque of the aircraft motor is unknown, and the load torque varies widely. The traditional V/f control is difficult to start reliably and run stably under this condition. To solve this problem, a closed-loop V/f control based on instantaneous power detection is proposed in this paper. By the disturbance of instantaneous active power, the angular velocity of the given voltage vector is compensated, the damping torque component of the system is increased, and the speed convergence is accelerated. By detecting the instantaneous reactive power, the magnitude of voltage vector is adjusted to make the motor work in the state of Maximum Torque Per Ampere and adapt to the sudden change of load torque. At the same time, the closed-loop transfer functions of traditional and improved V/f are obtained by simplifying the model, and the damping ratios of the two are compared. Finally, the simulation verifies that the improved closed-loop V/f control can reduce the speed fluctuation and speed convergence time, improve the current utilization rate, adapt to the unknown and sudden load torque, adjust the given voltage amplitude in time, and achieve reliable starting.