Coordinated Voltage Control Scheme for Voltage Regulating Devices in Hybrid Microgrid

Authors

Pragya, Ritula Thakur
National Institute of Technical Teachers Training & Research, Chandigarh, India.

Abstract

A slow voltage regulating device, an On-load tap changer transformers (OLTC), which have a poor response time, are actually better operated in the literature by adding a time delay to the fast-acting converters’ operation. Although the literature also suggests that the transitory condition has improved, it still idles the converters while waiting. There is therefore much room for improvement in the reactive power reserve. In this paper, we provide a coordinated voltage control (CVC) method that takes a novel approach, allowing the converters to absorb reactive power (of a particular voltage range from the grid) throughout the waiting period. In a real-time digital simulator platform, a modified IEEE 9-bus distribution system is modelled, and the simulation results are contrasted with those of existing and CVC-free methods. The simulation results demonstrate that the proposed CVC scheme is effective in increasing the reactive power reserve and voltage profile from the existing/without CVC system to 100 percent/164 percent and 0.0093 pu/0.014 pu, respectively. Additionally, compared to the existing/without CVC methods, the proposed CVC scheme reduces the postfault voltage recovery time by 20 ms/28 ms. These findings suggest that the suggested CVC scheme performs better under all grid operating scenarios.