Method of primary frequency modulation on-line automatic compensation system of thermal power generating unit

The invention belongs to the technical field of thermal power generating unit frequency modulation, and particularly relates to a method of a thermal power generating unit primary frequency modulation online automatic compensation system. The method comprises the following specific steps: performing primary frequency modulation instruction action; judging a current load control mode; calculating a corresponding coefficient a under the current load; calculating a correction coefficient b according to the deviation between the sliding pressure set value and the current main steam pressure; calculating a correction coefficient c according to the pressure deviation of the regulating stage before and after the primary frequency modulation action; inputting the finally determined compensation coefficient a, the compensation coefficient b, the compensation coefficient c and the primary frequency modulation instruction function into a multiplier unit MUL, and determining a steam turbine control valve increment instru