Investigations on TRIAC Based Speed Controller for a Single-Phase Induction Motor Ceiling Fans

The ceiling fans are most widely used electric appliance, and they use single phase induction motors (SPIMs). The speed control of them is traditionally achieved through the voltage control using a potentiometric divider. Recently, an energy efficient method of their speed control is used with a TRIAC based voltage controller. The constructional design of SPIM is such that there exists odd space harmonics along with tripplen harmonics. This leads to a high torque ripple in the motor leading to noise and vibration. Moreover, the use of a TRIAC based voltage controller induces time harmonics aggravating these problems. This paper analyses the impact of these harmonics on performance of the ceiling fan SPIMs. Three different commercial ceiling fans are tested and analyzed and compared with traditional resistive voltage control mechanism.