The invention discloses an AGC
control system for a 660MW supercritical unit under deep peak regulation, belonging to the technical field of AGC control. When the load of the unit is in a deep peak regulation interval, minimum
flow limitation is carried out on the flow of a gas pump; when the flow of a single gas pump is smaller than 425T / H, and a re-circulating valve of the gas pump is involved in gas pump
inlet flow regulation, is slowly started and is maintained to work over a minimum output; meanwhile, the
smoke temperature is increased at a boiler side, and a denitration wide load baffleis slowly turned down along the load of the unit so as to maintain the
smoke temperature of the unit under a
low load; and when the load of the unit is in a deep peak regulation interval, AGC speed isautomatically reduced through judgment, meanwhile, PID self-adaption and variable
parameter control of boiler main control and
steam engine main control can be realized through AGC, so that the
automatic control quality is improved. According to the AGC
control system, the following of the re-circulating valve and the denitration wide load baffle of a steam
feed pump along the automatic load control of the unit, the AGC
automatic control under deep peak regulation, the
steam engine main control PID self-adaption control and the boiler main control PID self-adaption control can be realized.