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Smart Modulation Methods for Energy Efficient Operation and Health Monitoring of Future Motor Drives

Periodic Reporting for period 1 - SmaMoMeMoDs (Smart Modulation Methods for Energy Efficient Operation and Health Monitoring of Future Motor Drives)

Reporting period: 2017-08-01 to 2019-07-31

Rotating field electrical motor driven systems are one of the key assets in reducing carbon emissions, since they are widely used in electrical energy production and end-use. This research project advances fundamental science in the field and develops new smart modulation methods for power converters. The power converters are used in diverse sectors, ranging from industrial to residential applications. In the industrial sectors the converters are used to rotate pumps, fans, conveyors, compressors as well as in heavy working machines and machinery. In transportation they are used in EVs, hybrid vehicles, trains, and ships and also aircrafts are becoming more and more electric. The voltage source converter is the most used power electronics configuration to enable accurate speed and torque control for rotating field machines. A DC voltage is modulated to AC voltage waveform using a pulse-width-modulation (PWM) technique. The PWM creates high frequency harmonic content to the voltage that causes an additional loss component to electrical machine. Generally, the amount of the harmonic losses is significant ranging from 5% to 50% of the electrical machines losses depending on the operation point. The additional harmonic loss component is not yet fully understood and it has been a controversial topic. To model the losses of the electrical machines with PWM-supply is still too complicated to be treated on a microscopic level. In the future, the FEM software employing advanced models can predict the electrical machine losses more accurately, but these kinds of models are far away from practical implementations. In here, a new research method to study harmonic losses were developed. The proposed electrical harmonic power approach is a simple and effective way to study the energy-efficiency of all electric apparatuses that utilize PWM. The approach will provide us the accurate data base to achieve precise results which the research will use for the development of a novel and efficient modulation method.
The work carried out during this project included scientific and complimentary skills training as well as research work. The scientific training included 3D modelling of electrical machines, power electronics modelling, current state of EVs' technology, system identification methods, silicon carbide devices, advanced modulation techniques and the measurement systems in automotive drives. The complimentary skills obtained during the project were communication, teaching and organisation skills, teaching skills, post graduate steering experience, dissemination of the results, the technical writing skills, financial management and funding proposal preparation.

The research work was conducted in the field of identification methods, studying the advanced current signature analysis methods for conditioning monitoring and energy efficiency of the different modulation methods.
The method developed during the project will finally reveal the dependency of the additional harmonic losses on load, its behavior as a function of the switching frequency and modulation pattern. These results will enable the development of new modulation techniques and new motor design principles. It is expected that the outcomes of the project to lead to a notable reduction on the energy consumption of motor drives. As electrical machines loss research stands today, the main efforts are too narrowly focused on simulation tools and modelling of the losses. The developed method and the related research creates a solid ground for further studies utilizing experimental measurements. These results will provide the basis for in-depth understanding of the harmonic losses in electrical machines. The proposed electrical harmonic power approach is a simple and effective way to study the energy-efficiency of all electric apparatuses that utilize pulse-width-modulation. The approach will provide us the accurate data base to achieve precise results which the research will use for the development of a novel harmonic control modulation method.