In this paper an exchange market algorithm approach is applied to solve highly non linear power system optimal reactive power dispatch problems . ORPD is most vital optimization problems in power system study and are usually devised as optimal power flow problem . The problem is formulated as nonlinear non convex constrained optimization problem with the presence of both continuous and discrete control variables . The EMA searches for optimal solution via two main phases namely balanced market and oscillation market . Each of the phases comprises of both exploration and exploitation which makes the algorithm unique . This uniqueness of EMA is exploited in this paper to solve various vital objectives associated with ORPD problems . Programs are developed in MATLAB and tested on standard IEEE 30 and IEEE 118 bus systems . The results obtained using EMA are compared with other contemporary methods in the literature . Simulation results demonstrate the superiority of EMA in terms of its computational efficiency and robustness . Consumed function evaluation for each case study is mentioned in the convergence plot itself for better clarity . Parametric study is also performed on different case studies to obtain the suitable values of tuneable parameters . susceptance of the lines connecting between bus and bus objective function conductance of transmission line between bus and bus stability index of th load bus number of generator busses or PV busses number of load busses or PQ busses number of tap changing transformers number of transmission lines number of shunt capacitors active power loss in MW minimum limit of active power output of slack generator of slack generator of slack generator of slack generator G1 active power generation of th generator active power load demand at th bus minimum limit of reactive power output of th generator maximum limit of reactive power output of ith generator reactive power generation for th generator reactive power load demand at th bus limiting value of reactive power generation of th generator reactive power output of slack generator G1 reactive power output of Shunt capacitor minimum value of reactive power output of th shunt capacitor maximum value of reactive power output of th shunt capacitor reactive power output of st shunt capacitor reactive power output of th shunt capacitor apparent power flow through th transmission line apparent power flow limit of th transmission line max . limit of apparent power flow through th transmission line shares of shareholders lower limit of thshare of th shareholder upper limit of th share of th shareholder variation in the share of th shareholder of the third group tap positions of tap changing transformers minimum position of th tap changing transformer maximum position of th tap changing transformer tap position of the first tap changing transformer tap position of the th tap changing transformer voltage of first generator G . magnitude of the load voltage voltage magnitude of the first load bus voltage magnitude of the th bus voltage magnitude of the th bus minimum voltage of. 


Summary: This paper presents a maiden application of EMA to solve power system ORPD problems. Steps of implementation of EMA to solve ORPD are elaborately discussed. The performance of EMA is tested on standard IEEE test systems. The selection of control parameters of EMA is done through exhaustive parametric study.