The Doubly-Fed Induction Generator (DFIG) has been traditionally used for wind turbines with limited speed ranges due to its good performance and a low cost partially-rated converter. However, significant maintenance requirements of the brush gear, vulnerability of the high-speed stage of a gearbox, and costly downtimes (especially off-shore), coupled with grid-code compliance issues under faulty operating conditions, represent serious DFIG’s disadvantages compared to synchronous generators. Reliable, maintenance-free, brushless doubly-fed generators (BDFGs) can overcome these DFIG limitations whilst retaining the cost-effectiveness of the fractional converter rating and the benefits of decoupled field oriented control. The main BDFG advantages over the DFIG are the brushless design, the medium speed nature allowing the use of a simpler 1-2 stage gearbox, proportionally lower fault current levels, and hence facilitated converter protection circuitries, afforded by the relatively higher leakage inductances.
In this project, a comparative control development and grid integration analyses of a promising BDFG reluctance rotor version, the Brushless Doubly-Fed Reluctance Generator (BDFRG), and a similarly rated DFIG will be made for performance comparisons. Realistic computer simulations using specialist software will be done at a large-scale (MW) level, whereas the existing laboratory test facilities for emulation of wind energy conversion systems based on each generator type will be used for the experimental work. Both normal and abnormal operation of the generators and their grid connection aspects including maximum power point tracking, low voltage ride through properties and/or frequency support capabilities, will be thoroughly investigated.
Given the scope and demands of the project, we are expecting one or two prospective PhD students to take part. Knowledge of the fundamental theory, dynamic modelling and power electronics control of electrical machines, digital signal processing and/or high-level computer programming would be preferable. The successful candidate(s) would be associated with the reputable Electrical Power and Control Systems research group.
This project is supervised by Dr. Milutin Jovanovic.
Please note eligibility requirement:
• Academic excellence of the proposed student i.e. 2:1 (or equivalent GPA from non-UK universities [preference for 1st class honours]); or a Masters (preference for Merit or above); or APEL evidence of substantial practitioner achievement.
• Appropriate IELTS score, if required.
For further details of how to apply, entry requirements and the application form, see https://www.northumbria.ac.uk/research/postgraduate-research-degrees/how-to-apply/
Please note: Applications that do not include a research proposal of approximately 1,000 words (not a copy of the advert), or that do not include the advert reference (e.g. SF19/EE/MPEE/JOVANOVIC) will not be considered.
Start Date: 1 March 2020 or 1 October 2020
Northumbria University takes pride in, and values, the quality and diversity of our staff. We welcome applications from all members of the community. The University holds an Athena SWAN Bronze award in recognition of our commitment to improving employment practices for the advancement of gender equality and is a member of the Euraxess network, which delivers information and support to professional researchers.
 F. Zhang, S. Yu., Y. Wang, S. Jin, M. G. Jovanovic, “Design and Performance Comparisons of Brushless Doubly-Fed Generators with Different Rotor Structures”, IEEE Transactions on Industrial Electronics, Vol. 66, No. 1, pp. 631-640, 2019.
 F. Zhang, H. Wang, G. Jia, D. Ma, M. G. Jovanovic, “Effects of design parameters on performance of brushless electrically-excited synchronous reluctance generator”, IEEE Transactions on Industrial Electronics, Vol. 65, No. 11, pp. 9179-9189, Nov. 2018.
 M. Cheng, P. Han, G. Buja, M. G. Jovanović, “Emerging Multi-Port Electrical Machines and Systems: Past Developments, Current Challenges and Future Prospects”, invited guest editorial paper, IEEE Transactions on Industrial Electronics, Vol. 65, No. 7, pp. 5422–5435, July 2018.
 A. B. Attya, S. Ademi, M. Jovanovic, O. Anaya-Lara, “Frequency support using doubly fed induction and reluctance wind turbine generators”, International Journal of Electrical Power & Energy Systems (Elsevier), Vol. 101, pp.403-414, Oct. 2018.
 M. Jovanovic and H. Chaal, "Wind Power Applications of Doubly-Fed Reluctance Generators with Parameter-Free Hysteresis Control”, Energy Conversion and Management (Elsevier), Vol. 134, pp. 399-409, 2017.
 S. Ademi, M. Jovanovic, H. Chaal and W. Cao, “A new sensorless speed control scheme for doubly-fed reluctance generators”, IEEE Transactions on Energy Conversion, Vol. 31, Issue 3, pp. 993-1001, Sept. 2016.
 S. Ademi and M. Jovanovic, "A Novel Sensorless Speed Controller Design for Doubly-Fed Reluctance Wind Turbine Generators", Energy Conversion and Management (Elsevier), Vol. 120, pp. 229-237, July 2016.
 S. Ademi and M. Jovanovic, "Control of Doubly-Fed Reluctance Generators for Wind Power Applications", Renewable Energy (Elsevier), Vol. 85, pp. 171-180, Jan 2016.
 S. Ademi, M. Jovanovic and M. Hassan, "Control of Brushless Doubly-Fed Reluctance Generators for Wind Energy Conversion Systems", IEEE Transactions on Energy Conversion, Vol. 30, No. 2, pp. 596-604, 2015.
 S. Ademi and M. Jovanovic, "Vector Control Methods for Brushless Doubly-Fed Reluctance Machines", IEEE Transactions on Industrial Electronics, Vol. 62, No. 1, pp. 96-104, January 2015.
 S. Ademi and M. Jovanovic, "High-Efficiency Control of Brushless Doubly-Fed Machines for Wind Turbines and Pump Drives", Energy Conversion and Management, Elsevier, Vol. 81, pp. 120-132, May 2014.