Abstract：Speed stabilization and frequency stabilization is the core control content of small hydropower stations. Real-time accurate frequency measurement is the premise of speed stabilization and frequency stabilization. On the basis of the current frequency measurement method, the half- period frequency measurement is realized by using the technology of field programmable gate array, which doubles the frequency measurement speed and provides conditions for fast, stable speed and frequency stabilization. The main idea is to count positive and negative half-cycles with two timers, and sum the two counters in each half-cycle to get the periodic value and cycle in turn. Secondly, in order to overcome the influence of noise bottom voltage when sine wave crosses zero point, the positive voltage bias is increased. Thirdly, high-frequency counting pulse is selected by using the high-speed multi-bit counting function of field programmable gate array to achieve high-precision frequency measurement.
周培孝, 刘吕娜, 严结实. 基于可编程芯片实现半周期精确测频及其在小水电站测频稳速中改造的应用[J]. 电气技术, 2019, 20(11): 77-81.
Zhou Peixiao, Liu Lvna, Yan Jieshi. Accurate frequency measurement based on field programmable gate array in half-period and the application. Electrical Engineering, 2019, 20(11): 77-81.
2019, Vol. 20 
