Insulation Degradation and Breakdown Modeling and Testing for Cables and Windings of Variable Speed Drives
Abstract
Project Summary: Insulation Degradation and Breakdown Modeling and Testing for Cables and Windings of Variable Speed Drives Variable speed machine drive (VSMD) systems from a few kW to tens of MW range are used on U.S. Navy ships for applications including ship propulsion, ship power generation, flywheel energy storage, compressors and pumps. These machines are currently driven by silicon-based power electronic devices that are switching at a high frequency from a few kHz to tens of kHz. With long power cables between the machine and the drive, the machine terminals are subjected to high voltage overshoot that imposes destructive electrical stress on the machine winding insulation system. Next generation wide bandgap (WBG) power electronics can operate under much higher temperatures at much higher switching frequencies (a few hundred kHz to MHz range). While the U.S. Navy is moving forward to use WBG power electronics, e.g., employing silicon carbide (SiC) and gallium nitride (GaN) devices, to drive machines for significantly improved system efficiency and power density, the cable and winding insulation system of electric machines will be subjected to tremendously increased electrical and thermal stresses that can significantly reduce the life time of the current insulation system. The technical objective of this research is to develop finite element (FE) models and computer-aided engineering (CAE) tools that can predict the accumulation of damage from the various stresses that cause insulation materials to degrade. The FE models and CAE tools will be used to compute the insulation degradation and breakdown of power cables and windings of VSMD systems. Then winding insulation degradation testing will be conducted using test fixtures that simulate partial function of an electric machine. The research is aiming to answer the following questions: 1) If the U.S. Navy replaces the current silicon based electric machine drives with drives based on next generation wide bandgap power electronics, how will the faster switching stress the insulation system of electric machines and how long can the current insulation system function properly without causing safety issues or failures? 2) What dielectric properties are required for the insulation system of an electric machine driven by WBG power electronic converters to enable the insulation to last for a desired period of time? 3) If the insulation material innovation is not capable of solving the insulation problem, what efforts are needed in the area of WBG power converter design to reduce the stresses on the insulation system? In addition, the research objectives will be enhanced by a multidisciplinary research collaboration between Oregon State University, The University of Texas at Austin, and The University of Connecticut. The research output will be maximized by synergistic activities including research exchanges, technical discussions, concurrent publications, and a workshop.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 12, 2016
- Source ID
- N000141512495
Entities
People
- Julia Zhang
Organizations
- Office of Naval Research
- Oregon State University
- United States Navy