An algebraic aggregation of interconnected power system loads

The electrical power system loads, as seen from a substation level, consist of numerous load elements and network elements. A subsystem consisting of load elements which are interconnected by network elements is connected to the rest of the power system at several points called reference nodes. This paper is concerned with a description of interconnected loads for a study of their interactions with the rest of the system through the reference nodes. The voltages at the reference nodes are the electrical inputs to the interconnected loads. Only balanced phase operations of symmetrical three phase loads are considered. The voltage dependencies of individual load elements are algebraically aggregated into a voltage dependent admittance matrix which describes the interconnected loads explicitly in terms of the voltages at the reference nodes.