Design of Intelligent Protection and Control Device for Medium and Small-Scale Asynchronous Motor

This chapter research the basic operation principle of asynchronous motor, perform an in-depth analysis of the characteristics of asynchronous motors of all kinds of faults occurred and the quantity relationship between the fault reason, to establish judgment of the stator current positive sequence, negative sequence, zero sequence components or their combination primarily, by detecting voltage, thermal resistance, external failure of complementary, multiple protective criteria, comprehensive protection scheme induction motor. And to motor working state of recognition, heat and cooling process unified heat capacity, the calculation formulas of zero sequence of protective grounding prevent abnormal operation measures to deal with the problem are discussed, and proposed a novel and simple and practical solutions.