University of Nottingham Ningbo China
Department of
Electrical and Electronic Engineering
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Power Electronic and Electrical Drive Research Group

This laboratory is aimed at starting up activities in electrical machines and their control at UNNC. Electrical machines are an enabling technology for more electrical drivetrains (automotive, marine, aerospace and rail), renewable and distributed generation and many industrial processes. A major research effort in machine topologies and their control is currently being undertaken by key research groups. The University of Nottingham has a world-leading centre of excellence in electrical machine technology (Cummins Innovation Centre in Electrical Machines) within the PEMC research group. The project will initiate research in a strategically important area at UNNC. It is foreseen that this project will initiate the research activities within the new machines lab at UNNC and collaboration between the two campuses in this area. 

Core technologies for VSC based multi-terminal high voltage DC networks for offshore wind farms--Funded by Ningbo government

 Large offshore wind farm grid integration

  • Almost all operated offshore farms are connected to the onshore power grids via undersea HVAC transmission cables over long distances.
  • With the increments of distances, the length of such AC cables is practically restricted by the capacitive charging current of the cable due to the high capacitance of shielded power cables.
  • HVDC technology can be used to transport electricity over long distances and to increase the overall controllability and stability of power systems.
  • Moreover, a number of large offshore wind farms could be interconnected by using a multi-terminal HVDC (MTDC) transmission system based on VSC and be linked to more than one country’s grid.

 

 

The MTDC technology requires lots of technical issues and needs to overcome challenges. The investigation includes:

  • Control strategies for MTDC—DC grid voltage control, power sharing and dispatch among the connected AC grids, voltage and frequency support of the connected AC grids, etc;
  • If there were particular changes in the network topology, the existing converters are able to maintain normal operation without necessarily adjusting their control parameters.
  • Controlling the direct voltage interchangeably and maintaining normal operation in the network upon losing a direct voltage controlling converter.
  • During faults in the onshore grids, de-loading at machine side, energy dissipation method and the frequency modulation method of the fault ride-through mechanism should be implemented.
  • MTDC safe operation.

 

High-bandwidth sensorless control of IPM motors

The purpose is to attain a high starting torque at zero speed and in subsequent extremely low speed range and extend up to high speed region by flux weakening. High dynamic performance can be achieved by high-bandwdith controller.

 

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