Controlled operation of brushless dc motor electrical engineer

Brushless dc motor (BLDCM) is in a brush dc motor on the basis of development, but its drive current

is a standard form of communication; Brushless dc motor and can be divided into rate of brushless

motors and brushless torque motor. Generally, there are two kinds of brushless motor drive current,

one kind is trapezoidal wave (usually "square"), the other is a sine wave. Sometimes called before a

brushless dc motor, the latter is called ac servo motor,www.dongfeng-motor.com
exactly is a kind of ac servo motor. General electrical engineer brushless dc motor in order to

reduce the moment of inertia, usually adopts the structure of "thin". Brushless dc motor on the

weight and volume than a much smaller brush dc motor, the corresponding moment of inertia can be

reduced by 40% - 50%. Because of the permanent magnetic material processing problems, the brushless

dc motor general capacity are below 100 kw. That the mechanical properties of the motor and

regulating characteristics of good linearity, wide speed range, long service life, convenient

maintenance noise small, does not exist a series of problems caused by brush, so this kind of motor

in the control system has great application potential. The stator winding of the motor to make more

balanced three-phase y connection, with three phase asynchronous motor is very similar. On the rotor

of the motor with the magnetization of the permanent magnet has, in order to detect the polarity of

the motor rotor, inside the motor is equipped with position sensor. Drive consists of power

electronic devices and integrated circuit, its function is: accept the motor start, stop, brake

signal, to control the motor start, stop,www.facebook.com/guohong.trading
and the brake; Accept the position sensor signals and positive &negative, used to control the

inverter bridge on and off of each power tube produce continuous torque; Accept the speed instruction

and speed feedback signal, which is used to control and adjust the speed; To provide protection and

display, and so on. Because of brushless dc motor based on self-control type operation, so don't like

frequency control of motor speed synchronous motor overload start under plus startup winding on the

rotor, also won't generate oscillation and step out when load mutation. Medium and small capacity of

the permanent magnet brushless dc motor (BLDCM), now more than using high magnetic energy product of

rare earth ndfeb material (Nd - Fe - B). As a result, the volume of rare earth permanent magnet

brushless motor than three-phase asynchronous motor with capacity reduces a frame number. General

electrical engineer pointed out that nearly 30 years study of asynchronous motor frequency control of

motor speed, in the final analysis is looking for a way to control the asynchronous motor torque,

rare earth permanent magnet brushless dc motor is bound to its wide speed range, small motor

fanvolume, high efficiency and steady speed water pump and small error

characteristics appeared in the field of speed advantage. For brushless dc motor has the

characteristics of a dc motor, is also the device of frequency variation, so also known as dc

frequency conversion, the international general term for BLDC) motors running efficiency of the

brushless dc motor, torque at low speed, precision of speed is more good than any of the control

technology of inverter, so the industry concern. This product has production more than 55 kw, can

design to 400 kw, can meet the requirements of industry energy saving and high performance drive.