Primary Frequency Regulation Method Optimization For Large Units

Grid frequency is one of the most significant index of power quality. Maintaining the stability of grid frequency is of great importance to the safe and stable operation of power system and electric equipment. Power generating from fossil fuels brings about large amount of carbon dioxide and pollutant discharge, which causes severe eco-environmental problems and endanger the sustainable development of human beings. Therefore, developing ultra-high voltage transmission and new energy generation has become an international trend. However, the dc block trouble of ultra-high voltage transmission and the intermittent power generation of new energy lower the degree of grid frequency stability. Therefore, the frequency and amplitude of primary frequency regulation would increase. At present, in order to participant in primary frequency regulation, thermal power units could not operate with governor valve fully opened, resulting in additional throttle loss, which would increase with the decrease of grid frequency stability. Therefore, how to reduce throttle loss under the premise of the primary frequency regulation requirements has been a hot research area of ultra-supercritical units.This paper takes full arc admission ultra-supercritical unit as research object and makes a comprehensive study on the reserved energy for primary frequency regulation both from the boiler and the turbine side. Afterwards, the impact of different primary frequency regulation measures on the power generating efficiency were calculated.This paper improved the veracity and precision of primary frequency regulation model and established ultra-supercritical unit primary frequency regulation simulation experiment platform based on National Instruments Labview. Then the dynamic behavior of different primary frequency regulation manners were studied based on simulation platform.This paper proposed primary frequency regulation optimization method based on the primary frequency regulation historical data between October 2015 and April 2016 which could not only reduce throttle loss during normal operation but also improve primary frequency regulation performance under dc block accident condition.