Optimal reactive power dispatch: a review, and a new stochastic voltage stability constrained multi‐objective model at the presence of uncertain wind power generation

In this paper, a comprehensive review of recent researches carried out in the area of optimal reactive power dispatch (ORPD) is presented. The literature review consists of a classification of ORPD problem, along with a survey on the strengths and weaknesses of different models proposed previously. Also, a stochastic multi‐objective ORPD (SMO‐ORPD) model is studied under load and wind power generation uncertainties. A two‐stage stochastic model is employed for dealing with the uncertainties. The considered objective functions are real power losses (PLs) and operation & maintenance (O&M) cost of wind farms (WFs). The proposed SMO‐ORPD problem is solved by considering voltage stability index (i.e. Lmax index). Besides, ɛ‐constraint technique and fuzzy satisfying approach are employed to pick up the best compromise solution. Two cases are considered as follows: (i) voltage stability relaxed SMO‐ORPD, and (ii) voltage stability constrained (VSC) SMO‐ORPD. In this study, reactive power compensation devices are modelled as discrete control variables. Hence, the proposed SMO‐ORPD problem is modelled as a mixed‐integer non‐linear programming optimisation problem. The SMO‐ORPD problem is implemented in GAMS environment, and it is examined on the IEEE 30 and 118‐bus test systems. The numerical results substantiate that in the case of VSC‐SMO‐ORPD, active PLs are higher than the other case, whereas O&M cost of WFs is not different considerably.