RESEARCH ARTICLE Fuzzy logic–based rooted tree optimization algorithm for strategic incorporation of DG and DSTATCOM Surajit Sannigrahi 1 | Sriparna Roy Ghatak 2 | Parimal Acharjee 1 1 Electrical Engineering Department, NIT Durgapur, Durgapur 713209, India 2 School of Electrical Engineering, KIIT University, Bhubaneswar 751024, India Correspondence Surajit Sannigrahi, Electrical Engineering Department, NIT Durgapur, Durgapur 713209, India. Email: surajit710@yahoo.in Summary In this study, a hybrid approach based on fuzzy logic and rooted tree optimiza- tion (RTO) algorithm is proposed for the strategic incorporation of distributed generation (DG) and distributed static compensator (DSTATCOM) in radial distribution system (RDS) to improve voltage profile, reduce losses, and maxi- mize economic and environmental benefits. Fuzzy logic is applied to bring the objectives in the same range, and using RTO technique, the optimal site and size of the devices are determined. Considering the uncertainty in DG's output and time‐varying system load, the proposed technique is tested on 69‐bus and 118‐bus RDSs, and to check the accuracy and feasibility, the simulation results are compared with other existing techniques. The Wilcoxon signed rank test (WSRT) is applied to confirm the superiority of the proposed algorithm. Fur- thermore, comparative performance analysis is conducted between different planning schemes for facilitating the distribution system planner to select the most suitable one. KEYWORDS DG, DSTATCOM, environmental benefit enhancement index, payback period, rooted tree optimization algorithm, Wilcoxon signed rank test 1 | INTRODUCTION In the present‐day scenario, power system utilities are operating closer to the stability margin because of the enormous load growth, restructuring of the power market, and undesired power flow. 1,2 The expansion of an existing network or the construction of new centralized generation units is not practically feasible because of various restrictions. 3 However, for the stable and secure operation of the power system, the enhancement of stability margin is essential in the context of restructured power market. 4 These issues divert the attention of distribution system planners towards distributed gen- eration (DG) and distributed static compensator (DSTATCOM). 5,6 Because of the increment of load demand in the recent time, DG can be used as an active power support that can also offer substantial advantages, such as line loss reduction, voltage profile enhancement, and greenhouse gas emission reduc- tion. 6-9 On the contrary, to enhance the stability and power quality, DSTATCOM is also used in radial distribution system (RDS) that can automatically compensate the reactive power according to system's variable load. 5,10,11 In addition, signif- icant benefits regarding line loss reduction, system voltage enhancement, and mitigation of power quality related prob- lems can also be obtained by deploying DSTATCOM in RDS. 12 Because of the reactive power injection by DSTATCOM and a significant reduction of losses, the power requirement for RDS will be less, and consequently, there will be a reduc- tion of the power taken from the grid. This is nothing but the energy savings that result in the economic benefits for RDS. Received: 6 August 2018 Revised: 25 February 2019 Accepted: 4 April 2019 DOI: 10.1002/2050-7038.12031 Int Trans Electr Energ Syst. 2019;e12031. https://doi.org/10.1002/2050-7038.12031 © 2019 John Wiley & Sons, Ltd. wileyonlinelibrary.com/journal/etep 1 of 30