Analyze the difference between DC motor / AC motor / electronic rectifier motor
According to foreign media reports, engineers usually choose between DC (DC) motors or AC (AC) motors. Recently, electronic rectification (EC) motors have also joined the melee, which helps control energy output and increase energy efficiency. The equipment is technologically advanced and is currently replacing DC motors and AC motors for efficiency adjustment. Electronic rectifier motors and DC brushless motors are controlled by external electronic circuit boards to improve control and efficiency.
Principles of DC and AC motors
The DC motor uses a carbon brush and a rectifying ring to change the direction of the current and magnetic field electrodes in the rotating armature. The interaction between the inner rotor and the stationary permanent magnet causes the motor to rotate.
According to maxon motors, DC motors are limited to brush systems and have a service life of 1000-1500 hours. Under extreme loads, they will be less than 100 hours. Under the condition of good working conditions, the operating life of some motors may reach 15,000 hours. In addition, high-speed rotation is limited by rectification, typically up to 10,000 times per minute (RPM).
DC motors have higher efficiency rates, but there are certain specific losses. The factors that cause failures include: initial resistance of the windings, brush friction and eddy-current loss.
ACinduction motors use a series of windings that are controlled by the AC input voltage and generate a stator field that produces the rotor field. The synchronous motor is another kind of AC motor, and its supply frequency (purchase frequency) is highly accurate. When the current passes through a slipring or permanent magnet, a magnetic field is generated. Synchronous motors run faster than induction motors, which are limited by the slip ring of an asynchronous motor.
An AC motor means that the operating value of the device will correspond to a specific point on the performance curve, which will be consistent with the peak efficiency of the motor. If it is not operated according to the value corresponding to this point, the efficiency of the motor will drop sharply. The AC motor generates an induced current on the rotor, which in turn generates a magnetic field, which leads to additional energy consumption. Therefore, AC motors are not as efficient as DC motors. In fact, the efficiency of a DC motor is more than 30% higher than that of an AC motor because the permanent magnet will produce a secondary magnetic field.
