Application of unified voltage analysis for high‐ and low‐voltage distribution systems by power flow calculation using indication method between nodes

It has been noted that the voltage of connection points rises according to the reverse power flow when grid-connected photovoltaic systems are concentrated in distribution systems in residential areas. When this happens, the photovoltaic system may control the power generation output to maintain a suitable voltage for the connection point. Designing a demand area power system aiming at free access to a distributed power supply for energy-effective practical use requires a precise understanding of this problem. When analyzing photovoltaic systems mainly connected to low-voltage systems, we looked for a method of analysis in which the high-voltage systems and the low-voltage single-phase three-wire systems are unified. This report concerns use of the indication method between nodes using power flow calculation, for the purpose of developing a technique of analyzing unified high-voltage systems and low-voltage single-phase three-wire systems. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 147(3): 49–62, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10255