The brushless DC motor is only composed of the main body of the motor and the driver, and it is a mechanized integrated product. Most of the stator windings of the motor are made into a phase-symmetrical star connection, and this structure is very similar to a three-phase asynchronous motor. The rotor of the motor will be bonded with some magnetized permanent magnets, and in order to be able to detect The polarity of the rotor is also installed with a position sensor inside, which is composed of power electronic devices and integrated circuits. The signal of the position sensor and the positive and negative, the signal can be used to control the channels of various power pipes, thereby generating a continuous torque.

It can accept speed vaccines and feedback signals, which can be used to adjust the speed of the motor, provide protection and display functions, and because the brushless DC motor operates in a self-controlled manner, it does not need to be restarted like variable frequency speed regulation, and at the same time There is no need to add another start winding on the device, and it is not necessary to generate oscillation when the load changes, and the brushless DC motor with medium and small capacity, its permanent magnets are mostly made of rare earth materials, so the brushless motor, it The volume is smaller than other motors by a frame size. The speed regulation is relatively wide, the volume is small, the efficiency is relatively high, and the error of the rotational speed is small, so its advantages in the transmission field are very obvious. The brushless DC motor is also a frequency changing device because of its straight brush and motor characteristics.

At present, we want to call it a DC variable frequency motor. Its operation efficiency is relatively high, and the precision of low-speed torsional rotation speed is relatively high, which is better than the frequency converter of other control technologies. Motor protection is the protection of the motor, that is, when the motor has overload, phase loss, locked rotor, short circuit, overvoltage, undervoltage, leakage, three-phase unbalance, overheating, bearing wear, stator and rotor eccentricity, axial movement radial When jumping, be protected. The device that provides protection for the motor is the motor protector, including thermal relays, electronic protectors and intelligent protectors. Large and important motors generally use intelligent protection devices.

The motor differential protection has differential quick-break protection and compound ratio differential protection with or without second harmonic braking, which can be used in the occasion of three-side differential current input (three-turn variable), and has the ability to simulate the voltage and current of primary equipment. The complete and powerful acquisition function of the switch value and the switch value can realize the three-turn main transformer differential protection, the two-turn main transformer differential protection, the two-turn distribution transformer differential protection, the generator differential protection, the motor differential protection and the non-contact through reasonable configuration. Protection and measurement and control functions such as power protection.