Voltage and Reactive Power Control Taking into Account of Economy and Security by using Tabu Search

Due to deregulation of electric power market, the several power transactions and the distributed generators will increase year by year. The power flow in power system will vary increasingly more complex and more uncertain by them. So it is difficult for Voltage and reactive power(Q) Control (VQC) to sustain the adequate voltages in the power system. On the other hand, the economy and security are requested for power system operation and control under the competitive environment. The optimization algorithm is effective to satisfy these trade-off problem. The optimization of VQC traces the combinational optimization problem with shunt devices, transformer tap and generator terminal voltage. Tabu Search (TS), which is one of meta-heuristic approaches, is suitable for the optimization problem of VQC. Because it is able to deal with the discrete variables such as shunt devices easily and it needs few tuning parameters.In this paper, in order to realize flexible VQC which responds to the uncertain power flow with competitive environment, we propose the optimization of VQC with TS algorithm taking into account of both economy and security. The security is considered as the minimization of generator reactive outputs and transformer tap positions difference from the neutral. Moreover, the novel neighborhood condition setting focused on the control interference between voltage control equipments is applied to minimizing the objective function. It is confirmed by several numerical simulations using IEEE 14 and 57 bus system that the proposed scheme is able to ensure the security and to find the useful optimal solution efficiently.