Closed loop flow detection in power systems based on Floyd-Warshall algorithm

The European transmission system operators of today have to struggle with a general increase in power flows, leading more and more to line congestions in certain transmission corridors. One reasonable countermeasure for this is active power flow control using power flow controlling devices (PFCD) like phase shifting transformers (PST) or Flexible AC Transmission Systems (FACTS). To avoid negative interdependencies between these utilities in different European control areas, the need for coordination of these PFCDs is expected to rise. During these coordination it is important to avoid the occurrence of closed loop flows after PFCD adaptation. Closed loop flows are circulated active power flows, which increase the grid losses. This paper proposes to use the shortest path method from Floyd-Warshall algorithm and adapt it for the detection of closed loop flows in power systems. The method is tested on standard IEEE test systems.