PERFORMANCE COMPARISON OF TRADITIONAL AND EMERGING DOUBLY-FED GENERATOR TOPOLOGIES FOR GRID-CONNECTED WIND POWER APPLICATIONS

Lead Research Organisation: Northumbria University
Department Name: Fac of Engineering and Environment

Abstract

Currently the accepted technology for large wind turbines is the doubly-fed induction generator (DFIG). This technology is popular primarily due to the reduced cost of the partially rated power electronic converter. On the negative side is the fact that the generator requires brushes and slip rings which require regular maintainance.An alternative scheme is based on the brushless doubly-fed reluctance machine (BDFRM) which also has the cost benefit of a partially rated power converter but as its name implies does not require brushes and slip rings.The BDFRM has not been used for a wind power application. This project will experimentally examine its performance for a wind power application. There are a number of different approaches to the control of a BDFRM. The project will examine the use of Direct Power Control (DPC). This control approach will include sensorless operation and machine parameter independence. With the proliferation of wind power generation the issue of power system stabilty is of great concern. It is important to examine the fault-ride-through (FRT) capabilty of any generation system. This project will examine the FRT capability of the BDFRM and compare this to that of the DFIG. This will require that special grid fault emulation equipment is included in the laboratory test rig.

Publications

10 25 50
 
Description (1) Investigation of a cost-effective, emerging generator topology (BDFRG) for grid-connected wind turbines, and its performance versus cost evaluation relative to an established, commercial, technology (DFIG) in order to overcome the main limitations of the latter in terms of compromised reliability and high running costs associated with brush gear;
(2) Development of a robust and versatile sensorless power control scheme for the BDFRG(M) suitable for variable speed constant frequency wind (hydro) power and/or industrial drive applications. The proposed control approach is entirely parameter independent and in many respects superior to all the existing model-based BDFRM algorithms reported in the open literature; (3) Essentially the same controller configuration could be used for the DFIG and similar advantages over the presently available control schemes for this machine could be achieved; (4) Avenues for further collaborative research with the industrial and/or academic partners on the project and wider have been opened as detailed in the further collaborations subsections resulting in new original research results, additional PhD completions and significant publication record which have arisen in the period 2012 to date.
Exploitation Route The research and industrial communities should be in a much better position to judge the merits of potential BDFRG use not only in grid-connected wind-turbine (or hydro) electricity generation but also in a variety of other markets traditionally served by DFIM including large pumps, compressors, fans, commercial heating, ventilation and air-conditioning systems, where the lower cost of the BDFRM, afforded by its brushless design, would ensure the energy savings and smaller pay-back periods. The BDFRG technology may also be an ideal candidate for off-shore wind power applications where it can offer improved reliability and lower operation and maintenance costs than the DFIG.

The main beneficiaries of the project results would be wind power industry and manufacturers of wind turbines (as well as electric drives in general due to the wider applicability of the project outcomes), as the research being undertaken would be of immediate relevance to them. This is foremost the case for collaborating countries, China, as one of the world's leading producers of wind energy, and UK, having the best wind resource in Europe. The consideration of promising generator topologies offering potentially significant cost benefits at competitive performance is an important research direction of common interest to the project partners and other parties in energy sector, and a solid foundation to sustain and further develop their collaboration in the future. Control of electric machines is an area of continuing interest to the broad international community, in both industrial and academic circles. The beneficiaries are therefore expected to be British and international electric equipment manufacturers through advancement in general knowledge on BDFRG/DFIG control.
Sectors Aerospace, Defence and Marine,Energy,Transport

 
Description There has been an increasing interest in the BDFRG technology and/or knowledge gained from reputable industrial companies (e.g. Rolls Royce, Siemens and others) where the former is being considered as a prospective alternative to commercial DFIG owing to the energy savings and smaller pay-back periods as well as superior fault-ride-through performance it may potentially offer especially in wind power applications, making so the doubly-fed family of machines more competitive with multi-pole synchronous generators on the market. An example of this initiative is certainly the knowledge transfer from academia to industry following the grant completion through the employment of Dr Chaal, who's been with renewable energy division of Siemens plc in Keele, UK, since 2011/12.
First Year Of Impact 2012
Sector Aerospace, Defence and Marine,Energy,Transport
Impact Types Societal,Economic

 
Description EPSRC project China call 
Organisation Newcastle University
Country United Kingdom 
Sector Academic/University 
PI Contribution This project was proposed and funded in response to a call for Collaborative Research with China focusing on Renewable Energy Technologies, including Hydrogen and Fuel Cells. The UNN team including myself as the principal investigator and a PhD student working on the project were involved in the development of a new sensorless controller for both the brushless doubly fed reluctance machine and the traditional doubly fed induction machine for performance comparisons under normal operating conditions.
Collaborator Contribution Newcastle University was the lead partner in this collaborative project as part of the related grant ref. EP/F061714/1 which was separately funded. Their research team investigated the comparative low voltage fault ride through capabilities of the two generator types being considered. Further details of interest may be found in the final report provided by this institution under the above reference. SSE made some in-kind contribution (difficult to quantify exactly) consisting of staff time of their employee involved with the project, and by providing wind energy data/experience used for simulation studies. The Chinese academic partner (SUT) provided design and manufacturing expertise for the BDFRG prototype. This work and maintenance grant for their visiting scholar were funded by Newcastle University from their grant referenced above. Further details should therefore be made available in their final report of research outcomes.
Impact The research results/outcomes of the project have been largely disseminated through journal and conference papers listed in this report.
Start Year 2008
 
Description EPSRC project China call 
Organisation Scottish and Southern Energy (SSE)
Country United Kingdom 
Sector Private 
PI Contribution This project was proposed and funded in response to a call for Collaborative Research with China focusing on Renewable Energy Technologies, including Hydrogen and Fuel Cells. The UNN team including myself as the principal investigator and a PhD student working on the project were involved in the development of a new sensorless controller for both the brushless doubly fed reluctance machine and the traditional doubly fed induction machine for performance comparisons under normal operating conditions.
Collaborator Contribution Newcastle University was the lead partner in this collaborative project as part of the related grant ref. EP/F061714/1 which was separately funded. Their research team investigated the comparative low voltage fault ride through capabilities of the two generator types being considered. Further details of interest may be found in the final report provided by this institution under the above reference. SSE made some in-kind contribution (difficult to quantify exactly) consisting of staff time of their employee involved with the project, and by providing wind energy data/experience used for simulation studies. The Chinese academic partner (SUT) provided design and manufacturing expertise for the BDFRG prototype. This work and maintenance grant for their visiting scholar were funded by Newcastle University from their grant referenced above. Further details should therefore be made available in their final report of research outcomes.
Impact The research results/outcomes of the project have been largely disseminated through journal and conference papers listed in this report.
Start Year 2008
 
Description EPSRC project China call 
Organisation Shenyang University of Technology (SUT)
Country China 
Sector Academic/University 
PI Contribution This project was proposed and funded in response to a call for Collaborative Research with China focusing on Renewable Energy Technologies, including Hydrogen and Fuel Cells. The UNN team including myself as the principal investigator and a PhD student working on the project were involved in the development of a new sensorless controller for both the brushless doubly fed reluctance machine and the traditional doubly fed induction machine for performance comparisons under normal operating conditions.
Collaborator Contribution Newcastle University was the lead partner in this collaborative project as part of the related grant ref. EP/F061714/1 which was separately funded. Their research team investigated the comparative low voltage fault ride through capabilities of the two generator types being considered. Further details of interest may be found in the final report provided by this institution under the above reference. SSE made some in-kind contribution (difficult to quantify exactly) consisting of staff time of their employee involved with the project, and by providing wind energy data/experience used for simulation studies. The Chinese academic partner (SUT) provided design and manufacturing expertise for the BDFRG prototype. This work and maintenance grant for their visiting scholar were funded by Newcastle University from their grant referenced above. Further details should therefore be made available in their final report of research outcomes.
Impact The research results/outcomes of the project have been largely disseminated through journal and conference papers listed in this report.
Start Year 2008
 
Description Further bilateral collaborations: Newcastle University 
Organisation Newcastle University
Country United Kingdom 
Sector Academic/University 
PI Contribution Control expertise in doubly-fed machines and drives.
Collaborator Contribution Design and control expertise in power electronics and digital signal processing (DSP) applications to doubly-fed machines and drives, including provision of the experimental facilities for testing purposes.
Impact Joint IEEE paper with D. Atkinson and W. Cao published in 2012 (refer to the Publications section for details) : multi-disciplinary in nature involving electric machines/drives, power electronics, computer engineering and digital signal processing.
Start Year 2012
 
Description Further bilateral collaborations: Strathclyde University 
Organisation University of Strathclyde
Country United Kingdom 
Sector Academic/University 
PI Contribution Control expertise on emulation of doubly-fed reluctance wind turbine generator characteristics using a standard induction motor drive, and dedicated testing facilities for laboratory experiments.
Collaborator Contribution Applied control engineering to electric drives and wind energy conversion systems.
Impact Multiple journal papers and book chapters published with S. Ademi from his PhD completion (Oct 2014), and subsequent employment with the Institute for Energy and Environment (Glasgow), to date. Further information on this joint publication record can be found in the Publication list.
Start Year 2014
 
Description Further multilateral collaboration: Strathclyde, Siemens and Qeen's/Aston 
Organisation Aston University
Department School of Engineering and Applied Science
Country United Kingdom 
Sector Academic/University 
PI Contribution Control expertise in electric drives and laboratory testing facilities for experiments.
Collaborator Contribution Control engineering applied to electric drives (Strathclyde), industrial experience/knowledge on the subject (Siemens) and condition monitoring of electric machines and power electronics (Queen's University Belfast/Aston University Birmingham)
Impact Two joint publications: (1) A conference paper titled: A Comparative Study of Robust Control Techniques for Doubly-Fed Reluctance Generators, presented and published in 2015 and (2) An IEEE transactions paper titled: A new sensorless speed control scheme for doubly-fed reluctance generators (currently in press - to appear in 2016), both on a multi-disciplinary subject involved the areas such as electric drives, power electronics, computer engineering, digital signal processing and control applications. Refer to the Publication list for further details.
Start Year 2012
 
Description Further multilateral collaboration: Strathclyde, Siemens and Qeen's/Aston 
Organisation Queen's University Belfast
Department School of Electronics, Electrical Engineering and Computer Science
Country United Kingdom 
Sector Academic/University 
PI Contribution Control expertise in electric drives and laboratory testing facilities for experiments.
Collaborator Contribution Control engineering applied to electric drives (Strathclyde), industrial experience/knowledge on the subject (Siemens) and condition monitoring of electric machines and power electronics (Queen's University Belfast/Aston University Birmingham)
Impact Two joint publications: (1) A conference paper titled: A Comparative Study of Robust Control Techniques for Doubly-Fed Reluctance Generators, presented and published in 2015 and (2) An IEEE transactions paper titled: A new sensorless speed control scheme for doubly-fed reluctance generators (currently in press - to appear in 2016), both on a multi-disciplinary subject involved the areas such as electric drives, power electronics, computer engineering, digital signal processing and control applications. Refer to the Publication list for further details.
Start Year 2012
 
Description Further multilateral collaboration: Strathclyde, Siemens and Qeen's/Aston 
Organisation Queen's University Belfast
Department School of Electronics, Electrical Engineering and Computer Science
Country United Kingdom 
Sector Academic/University 
PI Contribution Control expertise in electric drives and laboratory testing facilities for experiments.
Collaborator Contribution Control engineering applied to electric drives (Strathclyde), industrial experience/knowledge on the subject (Siemens) and condition monitoring of electric machines and power electronics (Queen's University Belfast/Aston University Birmingham)
Impact Two joint publications: (1) A conference paper titled: A Comparative Study of Robust Control Techniques for Doubly-Fed Reluctance Generators, presented and published in 2015 and (2) An IEEE transactions paper titled: A new sensorless speed control scheme for doubly-fed reluctance generators (currently in press - to appear in 2016), both on a multi-disciplinary subject involved the areas such as electric drives, power electronics, computer engineering, digital signal processing and control applications. Refer to the Publication list for further details.
Start Year 2012
 
Description Further multilateral collaboration: Strathclyde, Siemens and Qeen's/Aston 
Organisation University of Strathclyde
Country United Kingdom 
Sector Academic/University 
PI Contribution Control expertise in electric drives and laboratory testing facilities for experiments.
Collaborator Contribution Control engineering applied to electric drives (Strathclyde), industrial experience/knowledge on the subject (Siemens) and condition monitoring of electric machines and power electronics (Queen's University Belfast/Aston University Birmingham)
Impact Two joint publications: (1) A conference paper titled: A Comparative Study of Robust Control Techniques for Doubly-Fed Reluctance Generators, presented and published in 2015 and (2) An IEEE transactions paper titled: A new sensorless speed control scheme for doubly-fed reluctance generators (currently in press - to appear in 2016), both on a multi-disciplinary subject involved the areas such as electric drives, power electronics, computer engineering, digital signal processing and control applications. Refer to the Publication list for further details.
Start Year 2012