Running DC motor at higher than rated speeds

[zaman999]

Hi,
I had this power electronics lab experiment where we control the speed of a separately excited dc motor using thyristors. The dc motor is rated at 1500 RPM but we do get readings where the speed is above 2500 RPM. How is that possible?

Thanks

 

[Baluncore]

Without a load a DC motor will run at a speed determined by the average voltage provided. The motor speed specification also specified voltage and load. You have changed the voltage or load from those specified for that RPM.