Negative phase sequence recorder based on a single chip microcomputer

An investigation was conducted into the use of a negative phase sequence recorder for improving the voltage balance of a power system so as to reduce overheating and increase efficiency. It was considered that conventional recorders giving no phase information were inadequate. An improved instrument specification, based on an existing single chip microcomputer board, was proposed and developed for this application. Field trials were conducted on a typical rural system and the results presented in the form of polar plots. The instrument was used to obtain accurate measurements of amplitude and phase of negative phase sequence voltage. The microcomputer proved to be an economical solution, but required selection of a suitable algorithm to match its limited capacity.