**Publish at : ** 29 Apr 2018

**IJtech :** IJtech
Vol 9, No 3 (2018)

**DOI :** https://doi.org/10.14716/ijtech.v9i3.913

Arief, A., Nappu, M.B., Antamil, 2018. Analytical Method for Reactive Power Compensators Allocation.

241

Ardiaty Arief | - Department of Electrical Engineering,
Faculty of Engineering, Hasanuddin University,
Jl. Poros Malino Km. 6, Bontomarannu, Gowa 92172, INDONESIA - |

Muhammad Bachtiar Nappu | Department of Electrical Engineering, Faculty of Engineering, Hasanuddin University, Jl. Poros Malino Km. 6, Bontomarannu, Gowa 92172, INDONESIA |

Antamil | Faculty of Science and Technology, Department of Information Technology, Alauddin Islamic State University, Jl. H.M. Yasin Limpo No. 36, Gowa 92113, SULSEL, INDONESIA |

Abstract

This paper presents a novel analytical methodology to determine location for reactive power devices placement in power systems. The proposed method modifies modal analysis technique and develops new formulation to compute the Reactive Contribution Factor (RCF) of each load buses based on the inversed reduced Jacobian matrix. The objective of this research is to achieve the most stable condition as well as to minimize network losses. The proposed method is implemented at the modified IEEE 30-bus Reliability Test System (RTS) and compared with different placement. This work compares the voltage profile, eigenvalue and network losses to assess the method. The simulation results show the proposed method can provide a solution to the ideal shunt compensator placement to improve the system’s voltage stability and minimizing losses.

Eigenvalue; Losses reduction; Modal analysis; Reactive power compensator placement; Voltage stability

Introduction

For almost one century, system stability has been viewed as an important requirement for a power system to operate safely and reliably operation in (Dong & Zhang, 2009). Nowadays, modern power systems are severely stressed and work at the stability limit with smaller capacity and margin. Hence, these may cause congestion problems (Nappu et al., 2013; Nappu et al., 2014; Nappu & Arief 2016). The progressive and uncontrollable drop in voltage as a result of increase in load demand and, more especially, due to reactive loads or changes in system operation conditions, can result eventually in a widespread voltage collapse (Prada et al., 2015). Therefore, protective steps, such as load shedding, may be taken (Arief et al., 2013). In order to avoid this instability, there are several preventive steps that can be taken; one of them is the installation of a reactive power compensation scheme. This compensation device in the power system provides reactive power compensation; reduces network losses; reduces energy losses; improves the voltage profile; releases system capacity; and recovers the power factor (Sajjadi et al., 2013; Taher & Bagherpour, 2013; Arief et al., 2016).

In placing reactive power compensation devices, there are three issues that become major concerns; these are: namely, size of compensation; number; and location of placement (Kavousi-Fard & Niknam, 2013; Lee et al., 2015). Furthermore, with high penetration of renewable energy generations into power systems and, more especially, wind power plants, this has created more challenges in reactive power compensating planning (Xu et al., 2017). Hence, the daily maintenance, reliability and security of the system’s operation has become more difficult due to wind resources intermittency

Conclusion

This paper presents a new method for the placement of reactive power compensation devices by improving the Modal analysis technique by utilizing a direct connection between V & Q in the inversed reduced Jacobian matrix. This paper formulated a new Reactive Contribution Factor (RCF) computed from the elements of the inversed reduced Jacobian matrix. The RCF informs the size of the contribution of a specific bus from improving the voltage magnitude in critical buses. The greater a bus’ RCF, the greater that bus’ influence in improving the voltage of the critical buses.

The proposed method is tested on the modified IEEE 30-bus Reliability Test System. Based on the proposed method, the total reactive power compensator for the system is 15 MVar. With this amount, the proposed method was compared then with different compensators of 15 MVar placements. When of after capacitor placement, the system’s stability condition and network losses are based on the proposed method are compared to these different placements, the system’s overall voltage profile, based on the proposed method, is better than the system’s overall voltage profile if 15 MVar is placed in other buses.

Acknowledgement

The authors gratefully thanks the Indonesian Ministry of Research, Technology and Higher Education for providing the research grant and their support in this work.

References

Abul’Wafa, A.R., 2014. Optimal Capacitor Placement for Enhancing Voltage Stability in Distribution Systems using Analytical Algorithm and Fuzzy-real Coded GA. *International Journal of Electrical Power & Energy Systems*, Volume 55, pp. 246–252

Aman, M.M., Jasmon, G.B., Bakar, A.H.A., Mokhlis, H., Karimi, M., 2014. Optimum Shunt Capacitor Placement in Distribution System—A Review and Comparative Study. *Renewable and Sustainable Energy Reviews*, Volume 30, pp. 429–439

Arief, A., Antamil, Nappu, M.B., 2016. An Analytical Method for Optimal Capacitors Placement from the Inversed Reduced Jacobian Matrix. *Energy Procedia*, Volume 100, pp. 307–310

Arief, A., Dong, Z., Nappu, M.B., Gallagher, M., 2013. Under Voltage Load Shedding in Power Systems with Wind Turbine-driven Doubly Fed Induction Generators. *Electric Power Systems Research*, Volume 96, pp. 91–100

Carpinelli, G., Proto, D., Noce, C., Russo, A., Varilone, P., 2010. Optimal Allocation of Capacitors in Unbalanced Multi-converter Distribution Systems: A Comparison of Some Fast Techniques based on Genetic Algorithms. *Electric Power Systems Research*, Volume 80(6), pp. 642–650

Devabalaji, K.R., Ravi, K., Kothari, D.P., 2015. Optimal Location and Sizing of Capacitor Placement in Radial Distribution System using Bacterial Foraging Optimization Algorithm. *International Journal of Electrical Power & Energy Systems*, Volume 71, pp. 383–390

Dong, Z.Y., Zhang, P., 2009. *Emerging Techniques in Power System Analysis*. Springer

El-Fergany, A.A., Abdelaziz, A.Y., 2014. Capacitor Placement for Net Saving Maximization and System Stability Enhancement in Distribution Networks using Artificial Bee Colony-based Approach. *International Journal of Electrical Power & Energy Systems*, Volume 54, pp. 235–243

Gao, B., Morison, G.K., Kundur, P., 1992. Voltage Stability Evaluation using Modal Analysis. *IEEE Transactions on Power Systems*, Volume 7(4), pp. 1529–1542

Hamouda, A., Sayah, S., 2013. Optimal Capacitors Sizing in Distribution Feeders using Heuristic Search based Node Stability Indices. *International Journal of Electrical Power & Energy* *Systems*, Volume 46, pp. 56–64

Jabr, R.A., 2008. Optimal Placement of Capacitors in a Radial Network using Conic and Mixed Integer Linear Programming. *Electric Power Systems Research*, Volume 78(6), pp. 941–948

Kavousi-Fard, A., Niknam, T., 2013. Considering Uncertainty in the Multi-objective Stochastic Capacitor Allocation Problem using a Novel Self Adaptive Modification Approach. *Electric Power Systems Research*, Volume 103, pp. 16–27

Lee, C.-S., Ayala, H.V.H., Coelho, L.d.S., 2015. Capacitor Placement of Distribution Systems using Particle Swarm Optimization Approaches. *International Journal of Electrical Power & Energy Systems*, Volume 64, pp. 839–851

Nappu, M.B., Arief, A., Bansal, R.C., 2014. Transmission Management for Congested Power System: A Review of Concepts, Technical Challenges and Development of a New Methodology. *Renewable and Sustainable Energy Reviews*, Volume 38, pp. 572–580

Nappu, M.B., Arief, A., 2016. Network Losses-based Economic Redispatch for Optimal Energy Pricing in a Congested Power System. *Energy Procedia*, Volume 100, pp. 311–314

Nappu, M.B., Bansal, R.C., Saha, T.K., 2013. Market Power Implication on Congested Power System: A Case Study of Financial Withheld Strategy. *International Journal of Electrical Power & Energy Systems*, Volume 47, pp. 408–415

Nojavan, S., Jalali, M., Zare, K., 2014. Optimal Allocation of Capacitors in Radial/Mesh Distribution Systems using Mixed Integer Nonlinear Programming Approach. *Electric Power Systems Research,* Volume 107, pp. 119–124

Prada, R.B., de Souza, L.J., Lafitte Vega, J., 2015. The Need for Voltage Stability Analysis in Voltage-controlled Buses. *International Journal of Electrical Power & Energy Systems*, Volume 68, pp. 252–258

Radzi, N.H., Bansal, R.C., Dong, Z.Y., Hasan, K.N., Lu, Z., 2012. Overview of the Australian National Electricity Market Transmission Use of System Charges for Integrating Renewable Generation to Existing Grid. *IET Generation, Transmission & Distribution*, Volume 6, pp. 863–873

Raju, M.R., Murthy, K.R., Ravindra, K., 2012. Direct Search Algorithm for Capacitive Compensation in Radial Distribution Systems. *International Journal of Electrical Power & Energy Systems*, Volume 42(1), pp. 24–30

Ramadan, H.A., Wahab, M.A.A., El-Sayed, A.-H.M., Hamada, M.M., 2014. A Fuzzy-based Approach for Optimal Allocation and Sizing of Capacitor Banks. *Electric Power Systems Research*, Volume 106, pp. 232–240

Saadat, H., 1999. *Power System Analysis*. McGraw-Hill, Boston, U.S

Shuaib, Y.M., Kalavathi, M.S., Rajan, C.C.A., 2015. Optimal Capacitor Placement in Radial Distribution System using Gravitational Search Algorithm. *International Journal of Electrical Power & Energy Systems*, Volume 64, pp. 384–397

Sultana, S., Roy, P.K., 2014. Optimal Capacitor Placement in Radial Distribution Systems using Teaching Learning based Optimization. *International Journal of Electrical Power & Energy Systems*, Volume 54, pp. 387–398

Taher, S.A., Bagherpour, R., 2013. A New Approach for Optimal Capacitor Placement and Sizing in Unbalanced Distorted Distribution Systems using Hybrid Honey Bee Colony Algorithm. *International Journal of Electrical Power & Energy Systems,* Volume 49, pp. 430–448

Vuleti?, J., Todorovski, M., 2014. Optimal Capacitor Placement in Radial Distribution Systems using Clustering based Optimization. *International Journal of Electrical Power & Energy Systems*, Volume 62, pp. 229–236

Xu, Y., Dong, Z.Y., Zhang, R., Hill, D.J., 2017. Multi-Timescale Coordinated Voltage/Var Control of High Renewable-penetrated Distribution Systems. *IEEE Transactions on Power Systems*, Volume 32(6), pp. 4398–4408