如何控制無刷直流電動機的功率

　　無刷直流電動機（BLDC）的日益普及是由于使用電子換向。這取代了傳統的機械組成的刷子摩擦換向器上的直流電動機電樞繞組的活力。

　　電子換向提供了更高的效率比傳統的直流電動機與20至30%的電機在相同的速度和負載運行的改進。正如國際能源機構報告說，全球40%的電力用于電力電動機，這種效率的提高成為引人注目。

　　Further， the BLDC motor is more durable. It retains its high performance while the efficiency and power of an equivalent conventional motor declines due to wear， causing poor brush contact， arcing between the brushes and the commutator dissipating energy， and dirt compromising electrical conductivity.

　　Greater efficiency allows BLDC motors to be made smaller， lighter and quieter for a given power output， further increasing their popularity in sectors such as automotive; white goods; and heating， ventilation and air conditioning （HVAC）。 Other advantages of BLDC motors include superior speed versus torque characteristics （with the exception of torque at start-up）， a more dynamic response， noiseless operation， and higher speed ranges.

　　The downside of BLDC motors is their complexity and the associated increase in cost. Electronic commutation demands supervisory circuits to ensure precise timing of coil energization for accurate speed and torque control， as well as ensuring the motor runs at peak efficiency.