Method for coordinating and controlling quality change of coal in supercritical once-through boiler unit

The invention discloses a method for coordinating and controlling quality change of coal in a supercritical once-through boiler unit. The method is used for building a boiler master control provided with balanced indirect energy, and comprises the following steps: quantifying coal quantity by load; quantifying primary air quantity by the coal quantity; confirming a dominant role of instructions of the boiler master control; jointly debugging the ratios of wind, water and coal to ensure that the superheat degree of the boiler meets the requirement; meanwhile, ensuring the control precision of the front pressure of the boiler unit to meet the requirements of a power grid for changing range and speed rate. The method mainly solves the problem that the unit runs fast while the boiler efficiency is low, and builds a novel static feedforward, a load dynamic feedfoward, a pressure dynamic feedforward, and dynamic corrections of the feedforwards based on quality change of coal; the linkage of wind, water and coal quickens the responsiveness of the boiler; the joint debugging of water and coal solves the problem of quality change of coal, realizes the decoupling of water and coal and the decoupling of main steam pressure and superheat degree; the linear real-time coefficient modifies various experience curves; and a main steam pressure regulator of the boiler master control is subjected to the variable parameter control.