| This article based on the classic control theory, analyzed and discussed the control strategy that form the AGC (Automatic generate control) function of fire power plant thermal process control system. Modern control theory (adaptive control, anticipatory control, state space variable analyze) was used according to some special objects. In a power generating unit system, the boiler turbine and generator form an integrity, because the adapting load capability is quiet different between boiler and turbine, accordance control system is used to balance the output oftwo system with different dynamic character. Accordance control system (CCS) is the fundamental element of achieving the AGC function; the control quality of CCS is of very importance to win more power during the power net limited load change for independent power plant and service better for the power net and then achieve more benefit. This article emphatically discussed and analyzed following points: load command feed forward function can improve the rapid respond character of steam turbine generator; lead of load command have advance control function on boiler main control and can highly improve the stability of main steam pressure; the use of predict control and state space variable function can improve the quality of boiler steam temperature control effectively, control the steam temperature in the defined range and increase the boiler and turbine life and efficiency even if working state changed in a big range; linear compensation can restrain the vibration of generator load in the condition of big load change. Above problems are the hard point of CCS and then the key sections of AGC. Through analyzing and application, the design and tuning methods of big capacity fire power plant thermal control system are concluding .and put in service in actual project. Data draw from actual application of 4 X 350MW fire power plant shows that above control methods were succeed in AGC and other thermal control process. |
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