Omówiono jakim badaniom winno się poddawać silniki indukcyjne w napędach elektrownianych. Szczególną uwagę zwrócono na silniki WN klatkowe w napędach potrzeb własnych. Przedstawiono potrzebę badań symulacyjnych i warunki jakie muszą być spełnione aby ich wyniki były wiarygodne. Zwrócono uwagę na eksploatacyjne pomiary diagnostyczne pozwalające na ocenę stanu silników i przydatność do dalszej pracy. Pokazano możliwości jakie w tym zakresie stwarzają: badania stanu izolacji napięciem stałym, badania stanu konstrukcji mechanicznej stojana pobudzeniem przez impuls elektromagnetyczny.
The paper presents selected diagnostic tests which will be performed on induction motors used in electric drives in power plants[1, 2, 3]. In dynamic states, such as start-up, re-connection, etc., a rapid increase in the current and electromagnetic internal forces acting in the motor can occur. The dynamic states can cause a damage of the machine. There are proposed some dynamic simulation studies of electric drives as a method of diagnosing the causes of damage. The mathematical model of the induction machine (Section 2) [4, 5] [7, 8] is presented. There is also cited, previously developed by one of the authors , the method for determining the electromagnetic parameters of the model. In order to show the usefulness of the method, a comparison of measurements and calculations of some examples of dynamic processes is performed (Fig. 2). It concerns the energy-efficient induction motors  (Section 3). An example of comparison of the stator currents of energy-efficient motors obtained from simulating the dynamics of their start-up is presented in Fig. 5. It was noted that the damage of the rotor cage (Section 4) after improving the design of cages  and simplifying the methods for diagnosing the state of frames   ceased to be a frequent cause of the induction motor damages. Measurements of the insulation state by constant voltage excitation, introduced by T. Glinka [12, 13] and widely used in power industry , are discussed in Section 5 (Fig. 6). The ways of estimating the insulation state are presented in [14, 15]. The usefulness of this method was proved on the motors activated after the flood . The methods for testing the winding insulation are listed [17, 18, 19, 20]. The possibility of diagnosing the state of mechanical structures (housing, fixing, packages, etc.) by the method of stimulating with an electromagnetic pulse is also shown (Section 6). [14, 21].In the conclusions (Section 7) the necessity of dynamic simulation testing to verify the correctness of the selection of engines and to forecast the damages of engines is emphasized. The method for testing the winding insulation and the diagnosing of the state of mechanical structures by an electromagnetic pulse are assumed to be the ones of the future and development. The problem of diagnosing rolling bearing is not taken into consideration in the paper.