Work Package 1

1.1

1.2

1.3

1.4

1.5

1.6

1.1. Development and design optimisation of novel modular balanced multi-3-phase direct-drive PM generators.

Lead Partner: UoS (EMD)/SGRE; Co-Partners: UoH, UoS (DRG).

Objectives:
Development of novel, modular, balanced 3-phase direct-drive (DD) permanent magnet (PM) generator technologies with particular emphasis on improved manufacturability, transportability, reliability and performance.
Comparative study of alternative PM generator technologies to include power capability, power density, losses and efficiency, reliability, fault tolerance, etc., with the purpose of identifying the most appropriate generator topologies suitable for modular construction.

Key deliverables:
Novel modular multi-3-phase generators of high modularity, power density, efficiency, and fault tolerance, including developed topologies and optimal designs for the full and scaled size and power.

1.2. Development of novel modular multi-3-phase converters and control strategies.

Lead Partner: UoS (EMD)/SGRE, Co-Partner: DU.

Objectives:
Development of power electronic drives for modular wind turbine generators. A comparative study of alternative low and medium voltage converters including two-level and multi-level, multi-3-phase converters and converters for open-winding generators with the most promising technologies being selected for further detailed study. The detailed design study of the identified and developed modular 3-phase converters, which are most suitable for high power, low switching frequency operation, featuring with low harmonic distortion, low losses, and high efficiency, as well as low acoustic noise and EMC, etc., with particular focus on the specific issues associated with modularity. The investigation will also include pulse-width-modulation (PWM) and control strategies, featuring high modularity and high efficiency.

Key deliverables:
Novel modular converters, PWM and control strategies for modular 3-phase converters, including simulation of full system characteristics considering generator, converter and grid system.

1.3. Robust power converter design for large scale wind turbine application.

Lead Partner: DU/├śrsted, Co-Partner: UoS (EMD).

Objectives:
Power converter reliability is a major factor in the operating cost of wind turbines. This work will build on the outputs from a project that is currently being undertaken by an existing PhD student at Durham University and research activity currently ongoing by ├śrsted Energy. This project will aim to address topics such as: modularisation and redundancy to reduce the impact of failure modes, investigating the impact on failure rates of increasing system voltage to up-scale power rating rather than connecting identical power supply modules in parallel, and developing a reliability model of full converter system.

Key deliverables:
Guidelines for more robust power converter designs.

1.4. Parasitic effect and sensitivity studies, including noise and vibration, bearing current and manufacturing tolerances, rotor eccentricities etc.

Lead Partner: UoS (EMD)/SGRE, Co-Partner: UoS (DRG).

Objectives:
To investigate the influence of generator and converter designs on parasitic effects such as acoustic noise and vibration, bearing current, and the manufacturing tolerances and rotor static and dynamic eccentricities on the generator performance. Due to the modular structure, potential imbalances in modular segments and phase windings, manufacturing and assembly tolerances together with rotor static and dynamic eccentricities cause unwanted mechanical stress and harmonic distortion. Their influence on the mechanical and electromagnetic characteristics, as well as their design sensitivity, will be investigated, with particular emphasis on torque ripple, noise and vibration, bearing current, etc., leading to robust designs and novel analysis techniques to be developed. The investigation will benchmark against conventional generator designs.

Key deliverables:
Reports on investigation of noise and vibration, bearing current, manufacturing tolerances and rotor eccentricities, and the developed robust designs and analysis techniques.

1.5. Novel self-sensing control techniques for new modular generators.

Lead Partner: UoS (EMD)/SGRE, Co-Partner: DU.

Objectives:
To develop new self-sensing control techniques for zero/low and high speed operation of modular surface-mounted permanent magnet generators. Self-sensing control and detection of rotor position is an essential requirement in large wind power generators, due to the large shaft diameter which makes it impossible to fit a physical position sensor such as encoder or resolver to the system. During the maintenance cycle, there is a need for zero / low speed operation. Therefore, novel self-sensing techniques will be developed across the full usage profile of the system.

Key deliverables:
Report on new self-sensing control techniques developed for zero/low and high speed operations under both healthy operation, and fault conditions.

1.6. Validation of developed generators, converters and control strategies on scaled prototype systems.

Lead Partner: UoS (EMD)/SGRE, Co-Partner: DU.

Objectives:
To carry out the scalability study, and construct and test the scaled prototype generators and power electronics converter/control system. It is unrealistic to prototype the full-size multi-megawatt direct-drive permanent magnet generator. Therefore, scaled prototypes will be built and tested based on the developed concepts and designs, with a power level of around 3kW. It will include: scalability study; construction of the generator and power electronic system designs from WP1; utilisation of rapid development tools such as dSPACE to expedite the implementation process, avoiding unnecessary hardware development overheads; fabrication of test beds to allow testing of the individual sub-systems and enable full system tests. All test beds are to be fully equipped with data acquisition systems to facilitate monitoring and full characterisation of the elements under test. Prior to all construction a comprehensive CAE design will be undertaken, considering the tolerances and interface between the mechanical transmission and the power drive train in line with internal Siemens Design Standards.

Key deliverables:
Scaled prototype systems, test beds, and technical reports.