The Improvement On The Automation Control System Of Dong Fang Power Plant's 1000 MW Ultra Unit

With the rapid development of China's economic construction,environmental pollution has become increasingly serious.With the new policies and structural reform of energy supply side,the power market has gradually diversified,and new energy generation such as nuclear power,wind power,hydropower and photovoltaic has risen rapidly with the advantages of clean,efficient and renewable.Thermal power,as a traditional form of energy generation,is constantly facing new challenges,and the management situation of thermal power is becoming increasingly severe.Faced with the increasingly stringent requirements for technical indicators of thermal power plants in the two rules of environmental protection and power grid,environmental pollution,power generation costs,AGC(Automatic Generation Control),primary frequency modulation put forward higher requirements for the safety,energy saving and environmental protection of thermal power production.The original control strategy and control parameters of the automatic control system can not adapt to the rapid load changes and frequent network frequency fluctuations,and the quality of the unit's regulation becomes worse,which endangers the safe and stable operation of the unit.Taking Dongfang 1000 MW Ultra Supercritical Unit as an example,through in-depth analysis of the technical parameters of the three main engines of Dongfang,the principle and characteristics of the automatic control system for millions of units,the new requirements of AGC and primary frequency modulation for automatic control of power plants under the new situation,and comparing with the operation status of units,this paper finds out that the main steam appears in the original control system when the units are adapted to the rapid load rise and fall of AGC and the disturbance of Pressure fluctuation and large range of steam temperature rejection problems,and AGC and primary frequency modulation indicators do not meet the requirements of the two rules of North China Power Grid,facing millions of assessment costs every year.In view of the above problems,a highly targeted and effective automatic control strategy is formulated.Finally,the performance of the automatic control system is continuously improved through the automatic control improvement design of the maincontrol of the steam turbine,feed-forward of the main control variable parameters of the boiler,feed-forward of the primary air,feed-forward of the fast response of the AGC load and feed-forward of the primary frequency modulation.Through field test comparison,it is verified that the unit can adapt to the requirements of the power grid faster load change rate,higher load control accuracy,primary frequency modulation control accuracy has been improved,and the fluctuation range of the main controlled parameters is within the allowable range,which improves the unit's economy and security.