ALGORITHMS OF PROTECTION OF ELECTRIC MOTORS BY MEANS OF MODERN SYSTEMS OF DIAGNOSTIC OF THEIR STATES

Анотація

Traditional motor protection devices do not completely solve the problem of overload protection, damage to the power supply cable, distortion of phase currents associated with internal motor crashes, or deterioration of the insulation resistance of windings. requirements for reliable protection of the motor against overheating of the stator windings, caused by power supply asymmetry, damage to the cooling system and technological overloads, asymmetry air gap caused by wear of bearings, rotor jamming. The use of modern, reliable and effective protection against accidental operation modes can significantly reduce the number and frequency of accidents and lengthen the lifespan of electric motors, reducing power consumption and losses from the suspension process. The principles of protection of electric motors with the help of modern systems of diagnostics of power and technical states of the electric drive using thermal model of the engine and control of stator current are considered in the article. The thermal model takes into account heating losses, including losses from asymmetry and non-sinusoidal voltage. The overload characteristic of an electric motor is taken as a temporary characteristic of protection, its initial mode before the occurrence of an emergency and the current of the reverse sequence are taken into account. The article presents the algorithms of current and thermal protection that can be applied in the development of modern systems of diagnostics of the condition of the drive.