Document Type : Research Note

**Authors**

Department of Electrical Engineering, Sharif University of Technology, Tehran, Iran

**Abstract**

Microgrids (MGs) are designed to be able to serve hosting critical load in island-mode during major events. However, during normal condition when they are in grid-connected mode, MGs may have opportunity to achieve monetary profits through optimizing operation of energy resources and their participation in wholesale markets. This paper proposes a model to optimize MGs participation in the markets and operation of energy resources. Since MGs usually host renewable energy resources, making decision without considering the uncertainties may prone MGs to risk. So, the model considers uncertainties associated with generation of renewable DGs, demand, and market prices via robust optimization technique. The model is a max-min problem which is modelled as a bi-level optimization problem. The problem is solved in two iterative steps. In the first step, a genetic algorithm (GA) is applied to obtain the worst case wherein uncertain parameters are determined such that MG profit is minimized. Then, a mixed-integer linear problem is solved to maximize the profit over MG decision variables considering the values determined in the first step. The steps are iterated to converge to the best solution. To verify performance of the approach, it is applied to a typical MG and the results are reported.

**Keywords**

References:

1. Department of Energy, "Summary report: 2012 doe microgrid workshop", Chicago, Illinois, Jul (2012).

2. Parhizi, S., Lotfi, H., Khodaei, A., et al. "State of the art in research on microgrids: A review", IEEE Access, 3, pp. 890-925 (2015).

3. Ferruzzi, G., Cervone, G., Delle Monache, L., et al. "Optimal bidding in a day-ahead energy market for micro grid under uncertainty in renewable energy production", Energy, 106, pp. 194-202 (2016).

4. Mayhorn, E., Kalsi, K., Elizondo, M., and Butler-Purry, K. "Optimal control of distributed energy resources using model predictive control", IEEE Power and Energy Society General Meeting, pp. 1-8 (2012).

5. Hamidi, A., Nazarpour, D., and Golshannavaz, S. "Multiobjective scheduling of microgrids to harvest higher photovoltaic energy", IEEE Trans. Indust. Inform., 14(1), pp. 47-57 (2018).

6. Soroudi, A. and Amraee, T. "Decision making under uncertainty in energy systems: state of the art", Renewable and Sustainable Energy Reviews, 28, pp. 376-384 (2013).

7. Bagherian, A. and Tafreshi, S.M.M. "A developed energy management system for a microgrid in the competitive electricity market", IEEE Bucharest PowerTech, pp. 1-6 (2009).

8. Hemmati, M., Mohammadi-Ivatloo, B., Ghasemzadeh, S., et al. "Risk-based optimal scheduling of reconfigurable smart renewable energy based microgrids" , Int. J. Elect. Power Energy Syst., 101, pp. 415-428 (2018).

9. Shi, L., Luo, Y., and Tu, G. "Bidding strategy of microgrid with consideration of uncertainty for participating in power market", Int. J. Elect. Power Energy Syst., 59, pp. 1-13 (2014).

10. Nguyen, D.T. and Le, L.B. "Optimal bidding strategy for microgrids considering renewable energy and building thermal dynamics", IEEE Trans. Smart Grid, 5(4), pp. 1608-1620 (2014).

11. Ranjbar, H., Hosseini, S.H., and Kasebahadi, M. "Robust transmission expansion planning considering private investments maximization", IEEE Int. Conf. Power Syst. Tech. (POWERCON), pp. 1-6 (2016).

12. Street, A., Oliveira, F., and Arroyo, J.M. "Contingency-constrained unit commitment with n-k security criterion: A robust optimization approach", IEEE Trans. Power Syst., 26(3), pp. 1581-1590 (2011).

13. Bertsimas, D., Litvinov, E., Sun, X.A., et al. "Adaptive robust optimization for the security constrained unit commitment problem", IEEE Trans. Power Syst., 28(1), pp. 52-63 (2013).

14. Jiang, R., Wang, J., and Guan, Y. "Robust unit commitment with wind power and pumped storage hydro", IEEE Trans. Power Syst., 27(2), pp. 800-810 (2012).

15. Zhao, L. and Zeng, B. "Robust unit commitment problem with demand response and wind energy", IEEE Power and Energy Society General Meeting, pp. 1-8 (2012).

16. Alizadeh, B., Dehghan, S., Amjady, N., et al. "Robust transmission system expansion considering planning uncertainties", IET Gener. Transm. Distrib., 7(11), pp. 1318-1331 (2013).

17. Yu, H., Chung, C.Y., and Wong, K.P. "Robust transmission network expansion planning method with Taguchi's orthogonal array testing", IEEE Trans. Power Syst., 26(3), pp. 1573-1580 (2011).

18. Jabr, R.A. "Robust transmission network expansion planning with uncertain renewable generation and loads", IEEE Trans. Power Syst., 28(4), pp. 4558- 4567 (2013).

19. Chen, B., Wang, J., Wang, L., et al. "Robust optimization for transmission expansion planning: Minimax cost vs. minimax regret", IEEE Trans. Power Syst., 29(6), pp. 3069-3077 (2014).

20. Nojavan, S., Mohammadi-Ivatloo, B., and Zare, K. "Optimal bidding strategy of electricity retailers using robust optimisation approach considering time-of-use rate demand response programs under market price uncertainties", IET Gener. Transm. Distrib., 9(4), pp.328-338 (2015).

21. Thatte, A.A., Xie, L., Viassolo, D.E., et al. "Risk measure based robust bidding strategy for arbitrage using a wind farm and energy storage", IEEE Trans. Smart Grid, 4(4), pp. 2191-2199 (2013).

22. Liu, G., Xu, Y., and Tomsovic, K. "Bidding strategy for microgrid in day-ahead market based on hybrid stochastic/robust optimization", IEEE Trans. Smart Grid, 7(1), pp. 227-237 (2016).

23. Nojavan, S., Mohammadi-Ivatloo, B., and Zare, K. "Robust optimization based price-taker retailer bidding strategy under pool market price uncertainty", Int. J. Elect. Power Energy Syst., 73, pp. 955-963 (2015).

24. Soroudi, A. "Robust optimization based self scheduling of hydro-thermal genco in smart grids", Energy, 61, pp. 262-271 (2013).

25. Wang, L., Li, Q., Ding, R., et al. "Integrated scheduling of energy supply and demand in microgrids under uncertainty: A robust multi-objective optimization approach", Energy, 130, pp. 1-14 (2017).

26. Ji, L., Huang, G., Xie, Y., et al. "Robust cost-risk tradeoff for day-ahead schedule optimization in residential microgrid system under worst-case conditional value-at-risk consideration", Energy, 153, pp. 324-337 (2018).

27. Mehdizadeh, A. and Taghizadegan, N. "Robust optimisation approach for bidding strategy of renewable generation-based microgrid under demand side management", IET Renewable Power Generation, 11(11), pp. 1446-1455 (2017).

28. Attarha, A., Amjady, N., Dehghan, S., et al. "Adaptive robust self-scheduling for a wind producer with compressed air energy storage", IEEE Trans. Sustainable Energy, 9(4), pp. 1659-1671 (2018).

29. Heidarabadi, H., Hosseini, S.H., and Ranjbar, H. "A robust approach to schedule flexible ramp in Realtime electricity market considering demand response", 25th Iranian Conf. Elect. Eng. (ICEE), pp. 1159-1164 (2017).

30. Mashhour, E. and Moghaddas-Tafreshi, S.M. "Mathematical modeling of electrochemical storage for incorporation in methods to optimize the operational planning of an interconnected micro grid", Journal of Zhejiang University SCIENCE C, 11(9), pp. 737-750 (2010).

31. Algarni, A. and Bhattacharya, K. "A generic operations framework for discos in retail electricity markets", IEEE Trans. Power Syst., 24(1), pp. 356-367 (2009).

32. Habibifar, R., Karimi, M.R., Ranjbar, H., et al. "Economically based distributed battery energy storage systems planning in microgrids", 26th Iranian Conf. Elect. Eng. (ICEE), pp. 1257-1263 (2018).

33. Kazemi, M., Zareipour, H., Ehsan, M., et al. "A robust linear approach for offering strategy of a hybrid electric energy company", IEEE Trans. Power Syst, 32(3), pp. 1949-1959 (2017).

34. Bertsimas, D. and Sim, M. "Robust discrete optimization and network flows", Mathematical Programming, 98(1), pp. 49-71 (2003).

35. Tsikalakis, A.G. and Hatziargyriou, N.D. "Centralized control for optimizing microgrids operation", IEEE Trans. Energy Conv., 23(1), pp. 241-248 (2008).

2. Parhizi, S., Lotfi, H., Khodaei, A., et al. "State of the art in research on microgrids: A review", IEEE Access, 3, pp. 890-925 (2015).

3. Ferruzzi, G., Cervone, G., Delle Monache, L., et al. "Optimal bidding in a day-ahead energy market for micro grid under uncertainty in renewable energy production", Energy, 106, pp. 194-202 (2016).

4. Mayhorn, E., Kalsi, K., Elizondo, M., and Butler-Purry, K. "Optimal control of distributed energy resources using model predictive control", IEEE Power and Energy Society General Meeting, pp. 1-8 (2012).

5. Hamidi, A., Nazarpour, D., and Golshannavaz, S. "Multiobjective scheduling of microgrids to harvest higher photovoltaic energy", IEEE Trans. Indust. Inform., 14(1), pp. 47-57 (2018).

6. Soroudi, A. and Amraee, T. "Decision making under uncertainty in energy systems: state of the art", Renewable and Sustainable Energy Reviews, 28, pp. 376-384 (2013).

7. Bagherian, A. and Tafreshi, S.M.M. "A developed energy management system for a microgrid in the competitive electricity market", IEEE Bucharest PowerTech, pp. 1-6 (2009).

8. Hemmati, M., Mohammadi-Ivatloo, B., Ghasemzadeh, S., et al. "Risk-based optimal scheduling of reconfigurable smart renewable energy based microgrids" , Int. J. Elect. Power Energy Syst., 101, pp. 415-428 (2018).

9. Shi, L., Luo, Y., and Tu, G. "Bidding strategy of microgrid with consideration of uncertainty for participating in power market", Int. J. Elect. Power Energy Syst., 59, pp. 1-13 (2014).

10. Nguyen, D.T. and Le, L.B. "Optimal bidding strategy for microgrids considering renewable energy and building thermal dynamics", IEEE Trans. Smart Grid, 5(4), pp. 1608-1620 (2014).

11. Ranjbar, H., Hosseini, S.H., and Kasebahadi, M. "Robust transmission expansion planning considering private investments maximization", IEEE Int. Conf. Power Syst. Tech. (POWERCON), pp. 1-6 (2016).

12. Street, A., Oliveira, F., and Arroyo, J.M. "Contingency-constrained unit commitment with n-k security criterion: A robust optimization approach", IEEE Trans. Power Syst., 26(3), pp. 1581-1590 (2011).

13. Bertsimas, D., Litvinov, E., Sun, X.A., et al. "Adaptive robust optimization for the security constrained unit commitment problem", IEEE Trans. Power Syst., 28(1), pp. 52-63 (2013).

14. Jiang, R., Wang, J., and Guan, Y. "Robust unit commitment with wind power and pumped storage hydro", IEEE Trans. Power Syst., 27(2), pp. 800-810 (2012).

15. Zhao, L. and Zeng, B. "Robust unit commitment problem with demand response and wind energy", IEEE Power and Energy Society General Meeting, pp. 1-8 (2012).

16. Alizadeh, B., Dehghan, S., Amjady, N., et al. "Robust transmission system expansion considering planning uncertainties", IET Gener. Transm. Distrib., 7(11), pp. 1318-1331 (2013).

17. Yu, H., Chung, C.Y., and Wong, K.P. "Robust transmission network expansion planning method with Taguchi's orthogonal array testing", IEEE Trans. Power Syst., 26(3), pp. 1573-1580 (2011).

18. Jabr, R.A. "Robust transmission network expansion planning with uncertain renewable generation and loads", IEEE Trans. Power Syst., 28(4), pp. 4558- 4567 (2013).

19. Chen, B., Wang, J., Wang, L., et al. "Robust optimization for transmission expansion planning: Minimax cost vs. minimax regret", IEEE Trans. Power Syst., 29(6), pp. 3069-3077 (2014).

20. Nojavan, S., Mohammadi-Ivatloo, B., and Zare, K. "Optimal bidding strategy of electricity retailers using robust optimisation approach considering time-of-use rate demand response programs under market price uncertainties", IET Gener. Transm. Distrib., 9(4), pp.328-338 (2015).

21. Thatte, A.A., Xie, L., Viassolo, D.E., et al. "Risk measure based robust bidding strategy for arbitrage using a wind farm and energy storage", IEEE Trans. Smart Grid, 4(4), pp. 2191-2199 (2013).

22. Liu, G., Xu, Y., and Tomsovic, K. "Bidding strategy for microgrid in day-ahead market based on hybrid stochastic/robust optimization", IEEE Trans. Smart Grid, 7(1), pp. 227-237 (2016).

23. Nojavan, S., Mohammadi-Ivatloo, B., and Zare, K. "Robust optimization based price-taker retailer bidding strategy under pool market price uncertainty", Int. J. Elect. Power Energy Syst., 73, pp. 955-963 (2015).

24. Soroudi, A. "Robust optimization based self scheduling of hydro-thermal genco in smart grids", Energy, 61, pp. 262-271 (2013).

25. Wang, L., Li, Q., Ding, R., et al. "Integrated scheduling of energy supply and demand in microgrids under uncertainty: A robust multi-objective optimization approach", Energy, 130, pp. 1-14 (2017).

26. Ji, L., Huang, G., Xie, Y., et al. "Robust cost-risk tradeoff for day-ahead schedule optimization in residential microgrid system under worst-case conditional value-at-risk consideration", Energy, 153, pp. 324-337 (2018).

27. Mehdizadeh, A. and Taghizadegan, N. "Robust optimisation approach for bidding strategy of renewable generation-based microgrid under demand side management", IET Renewable Power Generation, 11(11), pp. 1446-1455 (2017).

28. Attarha, A., Amjady, N., Dehghan, S., et al. "Adaptive robust self-scheduling for a wind producer with compressed air energy storage", IEEE Trans. Sustainable Energy, 9(4), pp. 1659-1671 (2018).

29. Heidarabadi, H., Hosseini, S.H., and Ranjbar, H. "A robust approach to schedule flexible ramp in Realtime electricity market considering demand response", 25th Iranian Conf. Elect. Eng. (ICEE), pp. 1159-1164 (2017).

30. Mashhour, E. and Moghaddas-Tafreshi, S.M. "Mathematical modeling of electrochemical storage for incorporation in methods to optimize the operational planning of an interconnected micro grid", Journal of Zhejiang University SCIENCE C, 11(9), pp. 737-750 (2010).

31. Algarni, A. and Bhattacharya, K. "A generic operations framework for discos in retail electricity markets", IEEE Trans. Power Syst., 24(1), pp. 356-367 (2009).

32. Habibifar, R., Karimi, M.R., Ranjbar, H., et al. "Economically based distributed battery energy storage systems planning in microgrids", 26th Iranian Conf. Elect. Eng. (ICEE), pp. 1257-1263 (2018).

33. Kazemi, M., Zareipour, H., Ehsan, M., et al. "A robust linear approach for offering strategy of a hybrid electric energy company", IEEE Trans. Power Syst, 32(3), pp. 1949-1959 (2017).

34. Bertsimas, D. and Sim, M. "Robust discrete optimization and network flows", Mathematical Programming, 98(1), pp. 49-71 (2003).

35. Tsikalakis, A.G. and Hatziargyriou, N.D. "Centralized control for optimizing microgrids operation", IEEE Trans. Energy Conv., 23(1), pp. 241-248 (2008).

Transactions on Computer Science & Engineering and Electrical Engineering (D)

November and December 2021Pages 3480-3491