The new X9 plus power system has greatly improved in strength and efficiency. It uses a load of up to 13kg/axis,with a maximum pulling force of 26.5kg for 36-inch composite aviation folding blades.It is recommended to use 11-13kg single-axis load for better efficiency in the range of 11-12kg. The motor adopts the 9 series large load motor .The electromagnetic design and system optimization of the single-axis load(13kg) at fixed point strengthens the algorithm of the FOC application.