Bus voltage control and optimization strategies for power flow analyses using Petri net approach

Abstract

Distributed generation (DG) systems—particularly photovoltaic (PV) systems—that can control reactive power can change the behavior of a power system network in spite of their relatively small individual capacities because of bidirectional power flow and reactive power control. Therefore, power flow algorithms should be able to accurately model the response of a power system network that includes DG systems. Various power flow algorithms have modeled DG systems as either a P-Q or P-V bus. However, small DG systems connected to the grid by a short line, but not a long transmission line, or predefined mutually between utilities and DG system owners can participate in the control of reactive power. They can adaptively adjust the reactive power output according to their bus voltage. Thus, the objective of this study is to present a strategy that participates in the control of bus voltage within its limits and reactive power by either injecting or absorbing reactive power. For this purpose, this study presents a Petri net approach that a bus to which a DG system is connected is modeled as a P-Q or P-V bus with equality and inequality constraints. The proposed bus voltage control strategy is verified using the well-known IEEE test feeders.