Although not nearly as high in number as the simple squirrel cage induction motor, Synchronous motors are a major player in many industrial facilities. According to Market Research Future the 2023 market value of synchronous motors was US$22.84 Billion and growing! Synchronous motors often provide a dual role. First, they provide a constant speed at high power for applications like pumps, compressors and conveyors. Second, through field excitation control they can run at a higher power factor, which can improve a plant’s overall power factor and reduce electrical demand charges. The synchronous motor also runs 1-2% more efficiently than the induction motor. These energy related advantages are no small matter when your electric bills are in the hundreds of thousands of dollars annually.
The disadvantages of the synchronous motor focuses on the cost, speed control limitations, and not being self-starting (excitation requirements). Speaking of starting, the synchronous motor commonly has amortisseur windings/bars surrounding the DC rotor field poles to assist in starting the motor up as an induction motor before the external excitation energizes the field poles bringing the rotor into synchronous rotation with the stators rotating magnetic field. Performing a baseline In-Rush/Start-Up test is critical to capture the healthy induction startup and transfer to synchronous operation. This data will be priceless for future troubleshooting efforts as the motor ages.
To learn more about the Synchronous Motor, visit the PdMA Website at Podcasts | PdMA and listen to Episode 10 of the Todd and Noah Show Podcast.
