Optimal CONOPT solver-based coordination of bi-directional converters and energy storage systems for regulation of active and reactive power injection in modern power networks

Today's power systems are characterized by a considerable penetration of electricity production from renewable energy sources. However, renewable energy sources are characterized by intermittent non-stationary output, which leads to more complicated regulation of voltage, power flows, and frequency in power systems. Energy storage systems (ESSs) have been identified as one of the more efficient solutions to overcome some of these problems. In the literature, ESSs have been predominantly viewed as producers (in discharging) or consumers (in charging) of active power. Using bi-directional converters (BDCs), ESSs can regulate the connection point's reactive power. Therefore, this paper aims to consider the effects of the coordination of BDCs and ESSs on modern power systems. The CONOPT solver embedded in the general algebraic modeling system (GAMS) was used to analyze this problem and find the optimal location of ESSs in the system. All calculations were performed on both IEEE 39- and IEEE 30-test networks, while the objective function was minimizing the power loss. The presented results show that losses in the power system can be reduced by correctly allocating ESSs. Furthermore, the simultaneous allocation of ESSs and BDCs efficiently reduce power system losses using the CONOPT solver.