To the development of a model for the study of overvoltage in an asynchronous electric drive with a PWM frequency converter

Power supply of AC motors from semiconductor frequency converters with voltage inverters contains the risk of overvoltages on the supply line between the converter and the motor. The nature of overvoltages lies in the interference of the pulses generated by the converter with the signal reflected from the end of the supply line. Additionally, the amplitude can increase with superposition of high harmonics due to the phase velocity difference. Engineering concepts and research methods for these effects are well developed in relation to very extended objects and at a low frequency of the order of 50 Hz. In addition, the source of the signal is assumed to be the winding of the transformer or generator, which has a fundamentally limited rate of voltage change and is connected between the conductive elements of the electrical installation. When the line is powered from semiconductor switches (for example, IGBT), we have almost rectangular fronts and the voltage is applied to the conductive elements relative to a common point (“ground”), At the same time, for the effective use of the accumulated research complex of techniques, it is highly desirable to reduce the problem to traditional calculation schemes. This paper shows a possible reduction of the overvoltage research problem to such traditional design schemes, possibly with some reduction of parameters.