Performance Analysis of Variable Frequency Transformer for Power Flow In-between Synchronous Network Under Varying Voltage Conditions
DOI:
https://doi.org/10.13052/spee1048-5236.4427Keywords:
Variable frequency transformer (VFT), synchronous grid interconnection, power flow analysis, variable voltage conditions, typhoon HILAbstract
The Variable Frequency Transformer (VFT) is a controllable and bidirectional transmission device which integrates the principles of both rotatory transformer and phase shifting transformer, in order to regulate the power flow between two power grids. As most of the research work is focused on operating VFT at constant voltages; the analysis of VFT operating under varying voltage conditions remains unexamined. Keeping this gap in view, the paper presents detailed working of a VFT system used to control the power flow in-between synchronous grids operating under variable voltage conditions. For this, the two independent synchronous networks, under consideration, are connected to the stator and rotor winding of VFT, respectively. The power flow in-between the connected networks is first analysed under constant voltage conditions. The analysis shows that the power flow in-between the two synchronous connected networks, varies linearly with the applied torque and reverses as the direction of torque is reversed. The power flow is then analysed under variable voltage conditions, the obtained results show that reducing the voltage of either of the synchronous networks, increases the power flow towards that network while decreasing the power flow towards the other network. Further, the simulation results obtained using MATLAB/Simulink are validated using the real-time Typhoon HIL emulator.
Downloads
References
M. M. Khan, Imdadullah, J. Nebhen and H. Rahman, “Research on Variable Frequency Transformer: A Smart Power Transmission Technology,” in IEEE Access, vol. 9, pp. 105588–105605, 2021, doi: 10.1109/ACCESS.2021.3099747.
M. S. Thwala, A. F. Nnachi, K. Moloi and A. O. Akumu, “The Effect of a Phase Shift Transformer For Power Flow Control,” 2019 Southern African Universities Power Engineering Conference/Robotics and Mechatronics/Pattern Recognition Association of South Africa (SAUPEC/RobMech/PRASA), Bloemfontein, South Africa, 2019, pp. 425–430, doi: 10.1109/RoboMech.2019.8704776.
Z. Tan, C. Zhang, and Q. Jiang, “Research on characteristics and power flow control strategy of rotary power flow controller,” 2015 5th International Youth Conference on Energy (IYCE), Pisa, Italy, 2015, pp. 1–8, doi: 10.1109/IYCE.2015.7180825.
M. M. Khan, Imdadullah, J. Nebhen and H. Rahman, “Research on Variable Frequency Transformer: A Smart Power Transmission Technology,” in IEEE Access, vol. 9, pp. 105588–105605, 2021, doi: 10.1109/ACCESS.2021.3099747.
A. H. Sheikh and F. I. Bakhsh, Sustainable development and applications of variable frequency transformer (VFT), Sustainable Energy Technologies and Assessments, Volume 57, 2023, 103193, ISSN 2213-1388, https://doi.org/10.1016/j.seta.2023.103193.
A. H. Sheikh and F. I. Bakhsh, “Optimizing power system stability: An artificial neural network approach for controlling variable frequency transformer,” International Journal of Circuit Theory and Applications, 2023.
G. Chen, X. Zhou, and R. Chen, Variable Frequency Transformers for Large Scale Power Systems Interconnection: Theory and Applications. Hoboken, NJ, USA: Wiley, 2018.
E. R. Pratico, C. Wegner, P. E. Marken and J. J. Marczewski, “First multi-channel VFT application – the Linden project,” IEEE PES T&D 2010, New Orleans, LA, USA, 2010, pp. 1–7, doi: 10.1109/TDC.2010.5484379.
A. Merkhouf, P. Doyon and S. Upadhyay, “Variable Frequency Transformer – Concept and Electromagnetic Design Evaluation,” in IEEE Transactions on Energy Conversion, vol. 23, no. 4, pp. 989–996, Dec. 2008, doi: 10.1109/TEC.2008.2001460.
L. Contreras-Aguilar and N. Garcia, “Fast convergence to the steady-state operating point of a VFT park using the limit cycle method and a reduced order model,” 2009 IEEE Power & Energy Society General Meeting, Calgary, AB, Canada, 2009, pp. 1–5, doi: 10.1109/PES.2009.5275393.
B. Bagen, D. Jacobson, G. Lane and H. M. Turanli, “Evaluation of the Performance of Back-to-Back HVDC Converter and Variable Frequency Transformer for Power Flow Control in a Weak Interconnection,” 2007 IEEE Power Engineering Society General Meeting, Tampa, FL, USA, 2007, pp. 1–6, doi: 10.1109/PES.2007.385809.
J. J. Marczewski, “VFT Applications Between Grid Control Areas,” 2007 IEEE Power Engineering Society General Meeting, Tampa, FL, USA, 2007, pp. 1–4, doi: 10.1109/PES.2007.386183.
Y. Zhang, S. Huang, B. Ma, J. Zhu and G. Lei, “Variable Frequency Transformer Design for New Energy Microgrids and Grid Interconnections,” 2024 IEEE 21st Biennial Conference on Electromagnetic Field Computation (CEFC), Jeju, Korea, Republic of, 2024, pp. 1–2, doi: 10.1109/CEFC61729.2024.10585827.
B. B. Ambati and V. Khadkikar, “Variable Frequency Transformer Configuration for Decoupled Active-Reactive Powers Transfer Control,” in IEEE Transactions on Energy Conversion, vol. 31, no. 3, pp. 906–914, Sept. 2016, doi: 10.1109/TEC.2016.2550558.
B. B. Ambati, P. Kanjiya, V. Khadkikar, M. S. El Moursi and J. L. Kirtley, “A Hierarchical Control Strategy With Fault Ride-Through Capability for Variable Frequency Transformer,” in IEEE Transactions on Energy Conversion, vol. 30, no. 1, pp. 132–141, March 2015, doi: 10.1109/TEC.2014.2336981.
S. Z. Chen, J. Lu, G. Zhang and Y. Zhang, “Immunizing Variable Frequency Transformer From Dual-Side Asymmetrical Grid Faults via a Single-Converter-Based Novel Control Strategy,” in IEEE Transactions on Power Delivery, vol. 35, no. 3, pp. 1330–1338, June 2020, doi: 10.1109/TPWRD.2019.2940771.
F. I. Bakhsh, D. K. Khatod, Application of variable frequency transformer (VFT) for grid interconnection of PMSG based wind energy generation system, Sustainable Energy Technologies and Assessments, Volume 8, 2014, ISSN 2213-1388, https://doi.org/10.1016/j.seta.2014.09.003.
F. I. Bakhsh, and D. K. Khatod, “A new synchronous generator based wind energy conversion system feeding an isolated load through variable frequency transformer,” Renewable Energy, Elsevier, vol. 86, pp. 106–116, Feb. 2016. doi: 10.1016/j.renene.2015.07.093.
F. I. Bakhsh, D. K. Khatod, S. Islam and A. Iqbal, “Implementation of variable frequency transformer for integration of stand-alone wind energy conversion system with battery energy storage,” Journal of Energy Storage, Volume 90, Part A, 2024, 111752, ISSN 2352-152X, https://doi.org/10.1016/j.est.2024.111752.
L. Wang and L.-Y. Chen, “Reduction of Power Fluctuations of a Large-Scale Grid-Connected Offshore Wind Farm Using a Variable Frequency Transformer,” in IEEE Transactions on Sustainable Energy, vol. 2, no. 3, pp. 226–234, July 2011, doi: 10.1109/TSTE.2011.2142406.
S. Manzoor, M. D. Mufti, F. I. Bakhsh and A. Akbar. (2024). Type-2 fuzzy-based adaptively predictive controlled variable frequency transformer coordinated to SMES for improved load frequency control. IET Generation, Transmission & Distribution. 18. n/a–n/a. 10.1049/gtd2.13100.
M. M. Khan, Imdadullah and M. Bilal, “Effect of Unbalanced Grid Voltage Conditions on The Performance of a Variable Frequency Transformer,” 2023 International Conference on Power, Instrumentation, Energy and Control (PIECON), Aligarh, India, 2023, pp. 1–6, doi: 10.1109/PIECON56912.2023.10085818.
A. H. Sheikh and F. I. Bakhsh, “Reactive power management in variable frequency transformer (VFT)-integrated multi-machine power systems: A STATCOM-based approach,” International Journal of Circuit Theory and Applications, 53. doi: 10.1002/cta.4142, 2024.
B. Mushtaq and M. D. Mufti, “An adaptive wide-area neuro-fuzzy based controller for variable frequency transformer in damping inter-area oscillations,” e-Prime – Advances in Electrical Engineering, Electronics and Energy, Volume 7, 2024, 100409, ISSN 2772–6711, https://doi.org/10.1016/j.prime.2023.100409.
M. D. Golmaee, A. Koochaki and R. Soheil, “Variable frequency transformer equipped with dynamic breaking resistors for controlling low frequency oscillation using hierarchical strategy,” Electrical Engineering. 105. doi: 10.1007/s00202-022-01653-x, 2022.
B. Mushtaq and M. D. Mufti, “An adaptive wide-area neuro-fuzzy based controller for variable frequency transformer in damping inter-area oscillations,” e-Prime – Advances in Electrical Engineering, Electronics and Energy, Volume 7, 2024, 100409, ISSN 2772-6711, https://doi.org/10.1016/j.prime.2023.100409.
https://aeeeuropeenergy.com/
