definition：
EC (Electrical Commutation) The motor power supply is DC power supply, built-in DC to AC (through six inverter modules), rotor position feedback, three-phase AC, permanent magnet and synchronous motor. (DC brushless is only the appearance of power quality and motor, not the essence of motor，EC motor is essentially a three-phase AC permanent magnet synchronous motor).
Advantage：
EC motor is a DC brushless maintenance free motor with built-in intelligent control module. It has RS485 output interface, 0-10V sensor output interface, 4-20mA speed regulating switch output interface, alarm device output interface and master-slave signal output interface. This product has the characteristics of high intelligence, high energy saving, high efficiency, long service life, low vibration, low noise and continuous operation.
characteristic：
The brushless DC motor is greatly simplified in structure because the collector ring and brush for excitation are omitted. At the same time, it not only improves the process of the motor, but also greatly enhances the mechanical reliability of the motor operation and increases the service life
At the same time, the air gap magnetic density can be greatly improved, and the motor index can be optimally designed. The direct effect is that the motor size is reduced and the weight is reduced. Moreover, compared with other motors, it also has very excellent control performance. This is because: first, the torque constant, torque inertia ratio and power density of the motor are greatly improved due to the high performance of permanent magnet materials. Through reasonable design, the moment of inertia, electrical and mechanical time constants and other indicators can be greatly reduced, and the main indicators of servo control performance have been greatly improved. Second, the design of modern permanent magnet magnetic circuit has been relatively perfect. In addition, the coercivity of permanent magnet materials is high, so the anti armature reaction and anti demagnetization ability of permanent magnet motors have been greatly strengthened, and the control parameters of motors have been greatly reduced with the influence of external disturbances. Third, because permanent magnets are used to replace electric excitation, the design of excitation windings and excitation magnetic fields is reduced, so many parameters such as excitation magnetic flux, inductance of excitation windings, excitation current and so on are reduced, thus directly reducing controllable variables or parameters. Considering the above factors, it can be said that the permanent magnet motor has excellent controllability.
At present, many large capacity fans have adopted frequency conversion speed regulation to regulate air volume. This type of frequency converter mainly relies on imports, which is expensive. At present, fans with power level below 1kW, especially those for household air conditioners, have been driven by permanent magnet brushless DC motors and adopt speed regulation and air volume regulation. The fans in the power range of 1 ~ 10kW use a large amount of energy. They are basically driven by induction motors, and the air volume is adjusted by adjusting the opening of the air outlet. For fans within this power range, using permanent magnet brushless DC motor drive to replace the original induction motor drive has great advantages.
(1) Low loss and high efficiency
Because permanent magnet excitation is used, the loss caused by excitation current of induction motor is eliminated; At the same time, the permanent magnet brushless DC motor operates in synchronous mode, eliminating the rotation frequency loss of the rotor core of the induction motor. These two aspects make the operating efficiency of permanent magnet brushless DC motor much higher than that of induction motor, and the efficiency of small capacity motor is more obvious.
(2) High power factor
Since the excitation field of Brushless DC motor does not need reactive current of the power grid, its power factor is much higher than that of induction motor. Brushless DC motor can operate at a power factor of 1, which is extremely beneficial to small power motors. Compared with induction motor, brushless motor not only has higher efficiency and power factor at rated load, but also has advantages at light load.
(3) Good speed regulation performance and simple control
Compared with the variable frequency speed regulation of induction motor, the speed regulation control of Brushless DC motor is not only simple, but also has better speed regulation performance.
(4) Inverter capacity is low, so inverter cost is low
Brushless DC motor needs rectangular wave current, and the current rating of the inverter during continuous operation refers to the peak value of this rectangular wave. Induction motors need sine wave current, and the current rating of the inverter during continuous operation generally refers to the effective value of this sine wave. In order to maintain the control ability of the inverter over the motor current, there should be sufficient difference between the DC voltage of the inverter and the induced electromotive force of the motor. Therefore, the trapezoidal wave induced electromotive force of Brushless DC motor and the sinusoidal wave induced electromotive force of induction motor are limited by the DC voltage of the inverter. In this case, if it is assumed that the peak currents of the brushless DC motor and the induction motor are equal, the power output of the former is 33% higher than that of the latter, that is to say, the same rectifier / inverter can drive the brushless DC motor whose output power is 33% higher than that of the induction motor.