Optimal Control of a High-Power Permanent Magnet Synchronous Motor fed by Compact Bidirectional Converter (Compact_PMSM)

Electrification is popular like never before, and technology development makes this feasible for many different applications. However, the technology must be developed further to move on. Traditionally, winches on-board ships have mainly been hydraulic powered. However, in the recent years electric winches have taken a larger share of the market. In addition to the winch itself, the electric winch system consists of a gear, an electric motor, a frequency converter and a control cabinet, which are space demanding and complex to install. Flekkefjord Elektro are currently working on developing an ultra-compact electric winch, where the entire winch system is integrated into the winch drum. Such a winch is easy to install, on for example a ship, because the installation only consists of mounting one component and the connection of cables to the ship's power supply. To build a winch this compact, gears, electric motors, frequency converter and the control electronics must be optimized with regard to high efficiency and compactness. High efficiency means reduction of heat loss, therefore the physical size of the components can be reduced in several joints. To what extent this can be optimized is limited by the electromagnetic properties of the electromotor, as well as the characteristics of the semiconductor material in the transistors of the inverter. How the motor and inverter interact, is also an important factor. Transistors based on silicon carbide (SiC) as semiconductor materials are relatively new to the market, and have features that make it possible to achieve far better efficiency than the traditional silicon transistors. The challenge with the SiC transistors is that they are demanding to control and to fully use their potential. In this PhD project, different aspects of the PMSM like design procedure, demagnetization phenomena, power losses are studied. In addition, the numerical FEM (finite element method) and analytical models of the machine and its control are created in MATLAB and COMSOL. The goal is to enhance and optimize the control system and SiC transistors modulation to have a more efficient and reliable electric drive. At the start of the project, there has been a focus on building suitable test setup to experiment with how to optimize control of compact, permanent-magnet electric motors. The project has now built a small test setup with a voltage of 50V and a larger test set with a voltage of 400V. In the early stages, most experiments have been performed on the small test setup, but in recent times the larger test setup has got more focus. Simulation models are created and simulations are run based on the experiments. The biggest problems so far have been linked to real-time control in the larger test setup and modifications have been necessary to get the test setup appropriate for the experiments. Flekkefjord Elektro's R & D environment, FE create, has in another parallel project made a large test set-up with voltage up to 1000VDC at Mechatronics Innovation Lab in Grimstad. In this test setup we use FE create designed prototype compact electric motor with integrated frequency converter. This test setup is used in this PhD project. In this connection, the Phd project has made a simulation model of FE create electric motor and worked with it in parallel of experiments on this. Testing of PMSM at MIL has stopped in 2020. The Industrial PhD project will end on 31 December 2020 and the work and results will be continued in a new project at Flekkefjord Elektro.

In an increasingly tougher competition, the Norwegian shipbuilding industry has to find new and effective technologies for ship equipment via research and development (R&D) activities. Development of high-tech components with convenient installation and easy commissioning on board is very crucial not only for the future of SIMEK AS but also for other Norwegian shipyards. By converting the production from time-consuming to high-tech, Norway and other high-cost countries will have a big advantage. To achieve this, in collaboration with Semcon Devotek AS and University of Agder (UiA), we aim to develop an ultra-compact electric winch in the ongoing R&D Project entitled "Electric Winch with Ultra Compact Drive for Demanding Dynamics" (RFFA Project 256846). The developed winch will be a high-power density and extremely integrated system which allows reducing significantly the winch size while enhancing dynamics, maintenance and installation convenience. Such a winch will be revolutionary and provide significantly space-saving because the entire winch system is integrated into the winch drum. The High-Power Permanent Magnet Synchronous Motor fed by a Compact Bidirectional Converter based on Silicon Carbide (SiC) semiconductors is a key component in this winch. For us, a success of the ultra-compact SiC converter is a key step to for our long-term product development. Based on our current knowledge, the SiC based converters are very promising for new applications. Given the potential of electric winches and SiC based converters to shipbuilding industry, they can produce great value for our business. The PhD project proposes new converter designs and control algorithms, and then brings together the state-of-the-art methods with the objective of improving the efficiency, dynamics, and reliability of integrated electric winches. The acquired knowledge from the project can be used and further extended for other high-power machineries in maritime and offshore industry.