传统的风量调节一般采用调整风门的开启量大小 来进行，此时电机从电网吸收的有功功率基本不变，电机输出的机械功率有一部分消耗在“节流阀门”上，所以用“闸门”控制风量既不方便，又浪费能源。同样，采用在电机转子回路串电阻调速也可控制风量，但电机从电网吸收的功率一部 The traditional air volume adjustment is usually carried out by adjusting the opening amount of the damper. At this moment, the active power absorbed by the motor from the power grid is basically unchanged, and part of the mechanical power output by the motor is consumed by the “throttle valve” Air volume is not convenient, but also a waste of energy. Similarly, the motor rotor loop resistance speed control string can also be used, but the motor from the power grid to absorb a