Protection of Mains and Electric Motors on the Basis of Rapid Determination of Time Constant and Power Coefficient

To improve the quality of protection for mains and electric motors, it is expedient to additionally control the electromagnetic time constant. The necessary information is obtained from analyzing the sum of squared instant phase currents or the sum of instant phase powers. The determination of the time constant makes it possible to control the temperature of windings of electric motors, preventing them from overheating at direct frequent starts, and block network protection when starting electric motors, which allows implementing long-range redundancy protection and protection from remote short circuits.