Brushless dc motor controller have rapidly, large starting torque, rotating speed of from zero to the extra speed can supply additional torque of function, but direct current electrical and mechanical strengths also was wrong with it, because the dc electromechanical to additional load under a constant torque function, the armature magnetic field and rotor magnetic field must be constant maintain 90 °, this is about to borrow from the carbon brush and commutator. Carbon brush and commutator in mechanical and electrical migration change happens when the spark, carbon powder is besides will also damaged group a, using the site is restricted. Ac electrical without carbon brush and commutator, protection, strong, wide use, but to reach a match at dc electrical and mechanical characteristics of functional skills to reach with multifarious moderation. Today's semiconductor switching frequency speed up many growth agile power components, the promotion drive mechanical and electrical functions. Microprocessor speed is faster and faster, which can realize the exchange electromechanical control in a reverse two axis in the rectangular coordinates system, ac electrical and mechanical proper restraint in two shaft current weight, similar to dc electrical and mechanical control and a commensurate with dc mechanical and electrical functions. Many other existing microprocessor to control the function of the mechanical and electrical must do in chip, and volume smaller and smaller; Like to imitate/digital converter (模拟-数字转换器(ADC)And pulse width modulation (脉宽调制器,PWM)And so on. Brushless dc flash electricity is that electronic communication electrical and mechanical commutation method restraint, for similar dc electrical characteristics and without dc mechanical and electrical machine controller structure on the missing a should use. Dc without flash dc electric control layout without flash electricity is a kind of synchronous electrical and mechanical, that is to say, the mechanical and electrical rotor speed by electromechanical rate reverse magnetic field of the stator and rotor pole (P)F/P. In the case of rotor pole firmly, change the frequency of the stator reverse magnetic field can change the speed of the rotor. Brushless dc flash electricity is the synchronous electrical and electronic control (Drive), temperance reverse the frequency of the magnetic field of the stator and rotor of the electrical and mechanical speed feedback to moderate middle repeated revisions, in order to reach close to dc electrical and mechanical characteristics of the method. That is brushless dc flash electricity can perhaps within the scope of the additional load when the load changes can still control mechanical and electrical rotor rotating speed is constant.
