**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.

187

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.

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