Modeling and Simulation of Rotating Machine Windings Fed by High-Power Frequency Converters for Insulation Design

Abstract

Modern power systems include a considerable amount of power electronic converters related to the introduction of renewable energy sources, high-voltage direct current (HVDC) systems, adjustable speed drives, and so on. These components introduce repetitive pulses generated by the commutation of semiconductor switches, resulting in overvoltages with very steep fronts and high dielectric stresses. This phenomenon is one of the main causes of accelerated insulation aging of motors in power electronic-based systems. This chapter presents state-of-the-art computational tools for the analysis of motor windings excited by fast-front pulses related to the use of frequency converters based on pulsewidth modulation (PWM). These tools can be applied for the accurate prediction of overvoltages and dielectric stresses required to propose insulation design improvements. In the case of the stress-grading system used in medium-voltage (MV) motors, transient finite-element method (FEM) is used to study the effect of fast pulses. It is shown how, by controlling the material properties and the design of the stress-grading systems, solutions to reduce the adverse effects of fast pulses from PWM-type inverters can be proposed.

Insulating materials for realising carbon neutrality: Opportunities, remaining issues and challenges

“…An extensive research work on bulk modification such as mixing nano/micro particles into the base polymer matrix and surface modification such as plasma treatment, fluorination, magnetron sputtering, and ion beam implantation has been adopted to enhance the electrical and thermal properties of these insulating materials. Pablo Gómez and M. Khalil Hussain from Western Michigan University, USA have developed some motor simulation models under PWM waveforms [134]. Jiandong Wu group of Shanghai Jiaotong University and the international group of Haoyang you from Ohio State University, USA have presented discharge phenomena under DC and PWM waveforms [135,136].…”