Brushless dc motor is the electrical pulse signal into angular displacement or line open loop control elements of displacement. In the case of the overload, motor speed, stop position depends only on the pulse signal frequency and pulse number, and not affected by load change, which give the motor a pulse signal, a step from the Angle of motor is turning. The existence of a line of sex, add only periodic error of the brushless dc motor without cumulative error, etc. Made in the field of speed and position control with brushless dc motor to control becomes very simple. brushless dc motor is a kind of electrical pulses into angular displacement of the actuator. When brushless dc drive receives a pulse signal, it is set according to the direction of the brushless dc motor driven rotating a fixed Angle (Called & other; Interval Angle & throughout; ), its rotation is based on the Angle of the fixed step by step. Can be controlled by controlling the pulse number of angular displacement, so as to achieve the purpose of accurate positioning; As well as by controlling the pulse frequency to control motor rotation speed and acceleration, so as to achieve the purpose of regulating. Brushless dc motor can be as a control with special motor, using its no accumulated error (Accuracy of 100%)Characteristics, widely used in all kinds of open loop control. now more commonly used brushless dc motor including reactive brushless dc motor (VR）, permanent magnet brushless dc motor (PM), hybrid brushless dc motor (HB）And single phase brushless dc motor, etc. permanent magnet brushless dc motor, generally for two phase, torque and volume smaller, brushless dc Angle is commonly 7. 5 or 15 degrees; reactive generally for three-phase brushless dc motor, which can realize large torque output, brushless dc Angle generally to 1. 5 degrees, but the noise and vibration are very big. Reactive magnetic circuit of brushless dc motor rotor made of soft magnetic materials, multiphase field winding of the stator, the torque caused by the change of permeability. hybrid refers to a mixture of permanent magnet brushless dc motor and the advantage of reactive. It is divided into two and five phase: two phase brushless dc Angle generally to 1. 8 degrees and five phase brushless dc general Angle of 0. 72 degrees. The application of the brushless dc motor is more extensive, also the subdivided driving scheme chooses brushless dc motor. brushless dc motor with a technical parameters: the no-load start frequency, the brushless dc motor under the condition of light pulse frequency can normal boot, if the pulse frequency is higher than the value, the motor does not start properly, may be lost or blocked. In the load cases, start frequency should be lower. If you want to make the motor to achieve high-speed rotation, the pulse frequency should be to accelerate the process, namely the start frequency is low, and then in a certain high frequency acceleration to want (Motor speed from low speed to high speed)。 with its distinguishing feature of brushless dc motor (BLDCM), in the era of digital manufacture plays a significant purpose. With the development of different digital technology as well as the brushless dc motor itself, improve technology, brushless dc motor will be applied in more fields.
