To support a higher proportion of new energy power connected to the grid

coal-fired power units undertake more grid primary frequency regulation (PFR) tasks. How to scientifically and reasonably evaluate the PFR capability of coal-fired generating units is crucial for improving the unit operating level and increasing the production revenue. This paper analyzes the influencing factors of the PFR capability assessment of coal-fired power units

proposes the corresponding assessment indexes

and establishes an assessment model of the PFR capability of coal-fired power units based on the entropy weight method. Through the introduction of the main steam pressure refinement computation process

the paper proposes an improved method of calculating the performance indexes of the PFR capability based on the unit's output response. Using a 330 MW unit and a 670 MW unit as case studies

the accuracy of the proposed performance index calculation is verified

and the assessment model is applied to evaluate the PFR capability of both units. The results show that

compared with the traditional evaluation method

the method in this paper fully accounts for the influence of boiler dynamics and demonstrates better adaptability under variable operating conditions. Under normal and deep peak shaving conditions

the coefficients of determination for unit output response improved by 8.36% and 15.78%

while the ranges of PFR loads variation improved by 3.16 and 2.76 MW

which makes the evaluation results more realistic and helps to unlock the unit’s PFR potential.