We present an analysis of rotor voltage influence on the characteristics of a wound rotor induction motor, the speed of which is regulated by double feeding. Stator windings of the motor are fed from the power system, while the feeding for the rotor ones is provided by a cycloconverter. Expressions for all characteristic variables are derived on the basis of a mathematical model defined for particular operating conditions. Rotor voltage regulation laws, which ensure optimal motor operation according to predetermined criteria and apply to the entire regulated speed range, are defined from the obtained expressions.

Keywords: Doubly fed induction motor, Rotor voltage, Speed regulation