Binod Kumar SAHU, Manoj Kumar DEBNATH, Nimai Charan PATEL

Automatic generation control analysis of power system with nonlinearities and electric vehicle aggregators with time-varying delay implementing a novel control strategy Nimai Charan PATEL1∗,, Binod Kumar

Automatic generation control (AGC) also known as load frequency control plays a vital role in interconnectedpower system for frequency regulation. Electric vehicles (EVs) with battery as the storage device can participate infrequency regulation service. In practice, a large number of EVs are aggregated as a single unit called EV aggregatorfor participation in frequency regulation service in AGC system. Participation of EV aggregators in AGC systemfor frequency regulation will be encouraged in near future because EVs have less environmental pollution than theconventional vehicles. However, participation of EV aggregators in AGC system may introduce time delay whichdegrades the dynamic performance of the power system and even may lead to system instability. Further, generationrate constraint (GRC) and governor dead band (GDB) of synchronous generator introduce nonlinearity in the system,which adversely affects its dynamic performance. Hence, selection of an appropriate control strategy is essential forperformance enrichment of the power system. In this work, a PID-fuzzy-PID (PID-FPID) controller optimally designedby hybridizing particle swarm optimization (PSO) and modified sine cosine algorithm (MSCA) is proposed and a novelattempt is made to improve the frequency stability of a two-equal-area interconnected thermal power system with GDBand GRC incorporating an EV aggregators with time-varying delay in each area. Integral time absolute error has beenchosen as the objective function to optimally design the controller parameters. Dynamic performance of the system isalso investigated with proportional-integral-derivative (PID) controller optimally designed by PSO, sine cosine algorithm(SCA), MSCA, and hybrid PSO-MSCA. The efficacy and supremacy of the proposed hybrid PSO-MSCA-based PIDFPID control strategy is established by contrasting the results with the others. Finally, the robustness of the proposedcontrol strategy is validated by (i) including two EV aggregators with time-varying delay in each area, (ii) applying alarge disturbance of 0.4 p.u. in area-1, and (iii) applying a random load in area-1.

PDF

___

[1] Kempton W, Letendre SE. Electric vehicles as a new power source for electric utilities. Transportation Research Part D: Transport and Environment 1997; 2 (3): 157-175.
[2] Lopes JAP, Almeida PMR, Soares FJ. Using vehicle-to-grid to maximize the integration of intermittent renewable energy resources in islanded electric grids. In: IEEE 2009 International Conference on Clean Electrical Power; Capri, Italy; 2009. pp. 290-295.
[3] Brooks AN. Vehicle-to-grid demonstration project: Grid regulation ancillary service with a battery electric vehicle. Sacramento, CA, USA: California Environmental Protection Agency, Air Resources Board, Research Division: 2002.
[4] Liu H, Hu Z, Song Y, Lin J. Decentralized vehicle-to-grid control for primary frequency regulation considering charging demands. IEEE Transactions on Power Systems 2013; 28 (3): 3480-3489.
[5] Masuta T, Yokoyama A. Supplementary load frequency control by use of a number of both electric vehicles and heat pump water heaters. IEEE Transactions on Smart Grid 2012; 3 (3): 1253-1262.
[6] Sortomme E, El-Sharkawi MA. Optimal charging strategies for unidirectional vehicle-to-grid. IEEE Transactions on Smart Grid 2011; 2 (1): 131-138.
[7] Sortomme E, El-Sharkawi MA. Optimal scheduling of vehicle-to-grid energy and ancillary services. IEEE Transactions on Smart Grid 2012; 3 (1): 351-359.
[8] Sortomme E, El-Sharkawi MA. Optimal combined bidding of vehicle-to-grid ancillary services. IEEE Transactions on Smart Grid 2012; 3 (1): 70-79.
[9] Han S, Han S, Sezaki K. Development of an optimal vehicle-to-grid aggregator for frequency regulation. IEEE Transactions on smart grid 2010; 1 (1): 65-72.
[10] Lopes JAP, Soares FJ, Almeida PM. Integration of electric vehicles in the electric power system. Proceedings of the IEEE 2011; 99 (1): 168-183.
[11] Kempton W, Udo V, Huber K, Komara K, Letendre S et al. A test of vehicle-to-grid (V2G) for energy storage and frequency regulation in the PJM system. Results from an Industry-University Research Partnership, University of Delaware, Newark, DE, US: 2008.
[12] Bessa RJ, Matos MA. The role of an aggregator agent for EV in the electrical market. In: 2010 Mediterranean Conference and Exhibition on Power Generation, Transmission, Distribution and Energy Conversion (MedPower 2010); Agia Napa, Cyprus; 2010. pp. 1-9.
[13] Zhang CK, Jiang L, Wu QH, He Y, Wu M. Delay-dependent robust load frequency control for time delay power systems. IEEE Transactions on Power Systems 2013; 28 (3): 2192-2201.
[14] SÖNMEZ Ş, Ayasun S, EMİNOĞLU U. Computation of time delay margins for stability of a single-area load frequency control system with communication delays. WSEAS Transactions on Power Systems 2014; 9: 67:76.
[15] Macana CA, Mojica-Nava E, Quijano N. Time-delay effect on load frequency control for microgrids. In: IEEE 2013 International Conference on Networking, Sensing and Control; Evry, France; 2013. pp. 544-549.
[16] Ko KS, Sung DK. The effect of EV aggregators with time-varying delays on the stability of a load frequency control system. IEEE Transactions on Power Systems 2018; 33 (1): 669-680.
[17] Liu S, Wang X, Liu PX. Impact of communication delays on secondary frequency control in an islanded microgrid. IEEE Transactions on Industrial Electronics 2015; 62 (4): 2021-2031.
[18] Wen S, Yu X, Zeng Z, Wang J. Event-triggering load frequency control for multiarea power systems with communication delays. IEEE Transactions on Industrial Electronics 2016; 63 (2): 1308-1317.
[19] Kottick D, Blau M, Edelstein D. Battery energy storage for frequency regulation in an island power system. IEEE Transactions on Energy Conversion 1993; 8 (3): 455-459.
[20] Lee DJ, Wang L. Small-signal stability analysis of an autonomous hybrid renewable energy power generation/energy storage system part I: Time-domain simulations. IEEE Transactions on Energy Conversion 2008; 23 (1): 311-320.
[21] Khayyer P, Ozguner U. Decentralized control of large-scale storage-based renewable energy systems. IEEE Transactions on Smart Grid 2014; 5 (3): 1300-1307.
[22] Richard JP. Linear time delay systems: Some recent advances and open problems. IFAC Proceedings Volumes 2000; 33 (23): 5-19.
[23] Jeung ET, Kim JH, Park HB. Robust controller design for uncertain systems with time delays: LMI approach. Automatica 1996; 32 (8): 1229-1231.
[24] Ikeda M, Ashida T. Stabilization of linear systems with time-varying delay. IEEE Transactions on Automatic Control 1979; 24 (2): 369-370.
[25] Lee CH, Chang FK. Fractional-order PID controller optimization via improved electromagnetism-like algorithm. Expert Systems with Applications 2010; 37 (12): 8871-8878.
[26] Kennedy J, Eberhart R. Particle Swarm Optimization (PSO). In: 1995 Proceedings IEEE International Conference on Neural Networks; Perth, Australia; 1995. pp. 1942-1948.
[27] Eberhart RC, Shi Y. Comparison between genetic algorithms and particle swarm optimization. In: Springer 1998 International Conference on Evolutionary Programming; Berlin, Heidelberg; 1998. pp. 611-616.
[28] Mirjalili S. SCA: a sine cosine algorithm for solving optimization problems. Knowledge-Based Systems 2016; 96: 120-133.