Interturn Stator Voltage Distribution Due to Fast Transient Switching of Induction Motors

Steep fronted switching surges can cause severe stressing of the interturn insulation in induction motor windings. This may lead to failure. Experimental results show that severe nonlinearity in the voltage distribution within the coil can occur. it is shown that an analytical method of quantifying interturn surge capability is required, if test methods and design procedures are to be used with confidence. Such a method is described and shown to conform well with measured results. The use of surge protection devices is briefly considered.