Voltage Stability Constrained OPF in Multi-Micro-Grid Considering Demand Response Programs

In this article, a new approach is proposed for the voltage stability constrained optimal power flow in a multi-micro-grid (MMG) environment. In the proposed optimization problem, locational marginal pricing (LMP), demand response (DR) programs, active and reactive power generation cost for different types of renewable energy resources such as photovoltaic, wind turbine, microturbine, diesel generator, and combined heat and power (CHP) systems are used for real simulation of the MMG system. Two main types of DR programs, namely peak clipping and load shifting DR programs, are considered in the proposed methodology. In the peak clipping DR programs, LMP is calculated for each bus of the MMG. Then, the candidate loads, selected to be curtailed by the market mechanism, are paid based on the LMP values. In load shifting DR programs, the loads are paid for decreasing their amount of active power at peak hours. In this approach, the decreased active and reactive powers are shifted to off-peak times. The optimization method is formulated as nonlinear programing in GAMS software and simulated on a 55-bus MMG test system. The results of the proposed method are compared with the existing methods and the outcomes confirm that superior results in cost function are obtained using the proposed approach.