Title of Peer Reviewed and Accepted Research Paper
Benefits and weak points of various control strategies in enhancing variable speed wind turbine transient performance (Click here for full text access to the Paper, subscription or pay per view available)
Author:
- Kenneth E.Okedu, Department of Electrical and Electronic Engineering, Kitami Institute of Technology, Hokkaido, Japan
What are the key findings of your research (in brief)?
A new control strategy for Doubly Fed Induction Generator (DFIG) considers a Current Controlled Voltage Source Converter (CC-VSC), which has fewer intricacies in the converter design (DC-link, chopper circuitry and reduced Proportional Integral Controller were not investigated).
The performance of this scheme in the DFIG system during grid fault scenario was compared to the performance of other DFIG Fault Ride Through (FRT) solutions. The other schemes considered were:
- Voltage Controlled Voltage Source Converter (VC-VSC);
- DC chopper protection scheme;
- VC-VSC with an active Crowbar Switch at the Rotor Side Converter (RSC) of the DFIG Variable Speed Wind Turbine (VSWT);
- VC-VSC with STATCOM FACTS reactive power compensation;
- VC-VSC with Series Dynamic Braking Resistor (SDBR) at the rotor side of the DFIG system;
- VC-VSC with SDBR at the stator and the grid side of the DFIG system;
- Combined VC-VSC for RSC and CC-VSC for Grid Side Converter (GSC) approach for the DFIG;
- Parallel interleaved voltage source power converters for the DFIG.
It was discovered that the proposed CC-VSC based DFIG control offers better performance of the wind turbine variables during transient period and is therefore more economical, since it does not require external circuitry.
Why do your findings matter?
The Current Controlled Voltage Source Converter DFIG topology offers a cheap and effective way of enhancing the performance of grid-connected wind farms based on the recent grid requirements.
How will this make a difference to the implementation of sustainable energy?
Wind turbine developers could design this proposed Current Controlled DFIG wind turbine power converter scheme to keep the wind farms grid connected during fault conditions.
This control strategy could also help keep obsolete fixed speed wind turbines in operation by developing wind farms that are composed of fixed and variable speed wind turbines. Instead of phasing out fixed wind turbines, they could be operated in parallel with the DFIGs variable speed wind turbines, thus using some of the characteristics of the fixed speed wind turbines (such as robustness and low maintenance cost).
What are the next steps that need to be taken to push this research forward even more?
Collaboration with academics and wind turbine developers.
Accessing the full text version of the Paper
Benefits and weak points of various control strategies in enhancing variable speed wind turbine transient performance (Click here for full text access to the Paper).