Analysis and Comparison of Methods of Frequency Measurement for Generators in Parallel

When a generator is paralleled with the net, the frequency of the generator and the net must be the same. This article compared several digital methods of frequency measurement for generators in parallel: direct frequency measurement, period measurement, simultaneous frequency measurement in many periods, frequency measurement based on cross algorithm, curve fitting with three points, frequency measurement based on F transformation and frequency measurement based on ANN. The authors of the article analyzed errors of each method, pointed out the optimum usage and provided a guide for selection in application.