A high precision fundamental frequency measurement method based on FPGA

Accurate fundamental frequency measurement has a significant role in synchronous sampling and power parameter analysis. However, the large amount of harmonics appearing in circuits makes it difficult to measure the fundamental frequency. ln this work, we propose a fundamental frequency measurement architecture that combines FFT algorithm with period measurement method. This method can reduce the frequency resolution limitation in FFT between sampling rates and calculating length. This integrated method is appropriate to measure the fundamental frequency of signal that contains a large amount of harmonics. Experimental results show that the frequency of signal with large amplitude harmonics can be measured accurately by using the proposed structure.