Computer model-based evaluation of energy losses components in the systems with asynchronous machines and transistor converters

The paper describes a model of the PWM inverter fed induction machine. The model is built up by decomposition of a system into subcircuits that are coupled by means of dependent voltage/current sources. Such an approach ensures high flexibility in constructing the system models along with acceptable accuracy of computation. The model considered is shown to comply with basic properties of real machines and enables to calculate transitive and steady-state responses as well as to evaluate components of energy losses in the system. Based on model and experimental data, frequency dependent energy losses in an asynchronous machine due to PWM inverter high-order harmonics are analyzed.