Abstract:This paper analyzes the problems existing of single-unit AGC from six aspects, and points out that this method increases the overall coal consumption and power consumption of the power plant, and affects the economy and safety of the unit. The principle, system structure and main functions of plant-level AGC are expounded, The plant-level AGC can be operated according to the coal consumption rate, response rate, regulation range and operating conditions of each unit.the optimal load distribution of the whole plant is automatically and reasonably carried out, the power generation cost is effectively reduced, and the unit is efficiently and economically operated, therefore, it is necessary to carry out plant-level AGC transformation. This paper expounds the distribution strategy of factory-level AGC from three aspects of load rise, drop and stabilization, puts forward the principles that must be adhered to in the transformation of factory-level AGC, summarizes the operation mode after the transformation, analyzes the causes of the three phenomena of single-machine instruction jump, single-machine instruction zero, and automatic withdrawal from factory-level AGC, and puts forward the solutions. Load arrangement is required to improve unit economy by optimizing the operation mode of unit with load. Finally, the operation effect of the retrofitted unit is introduced, which has a strong guiding significance for the retrofitting of multi-unit AGC in power plant.