Analysis And Research Of Automatic Generation Control Coal-fired Units

Due to the increasingly serious problem of energy crisis, people are increasingly demanding for the economy and stability of coal-fired units. With the increasing demand for electricity and the increasing grid size, super(super)critical units also need to participate in the grid frequency peaking. Now how to maintain the stability of the grid frequency cost-effectively has become a hot topic of research for electricity workers. Common means of maintaining stability are primary frequency and secondary frequency. Primary frequency regulation is a differential regulation which can only ease the degree of deviation from the grid frequency. But it can not achieve the exact requirements of the frequency. In order to improve the stability of the power grid, reducing the frequency of fluctuations in the power grid, and enhance power grid capacity of anti-accident, more and more coal-fired units also need to adjust the load according to the instructions issued by the grid dispatching center. This process is called secondary frequency, also known as automatic generation control(AGC).According to the scene debugging experience, this paper analyzes the super(super) criticality coal-fired units of automatic generation control(AGC) function. First this paper analyzes the process of realizing AGC function in thermal power plants. Under the "Two Rules", this paper defines the function of automatic generation control assessment criteria and evaluation. Through the above analysis and research, this paper gets two major factors affecting AGC function realization. The first factor is the method of sliding pressure curve setting. The second factor is the steam temperature fluctuations to the secondary frequency. Then this paper proposes an optimization program about AGC defect existed in a power plant. On the one hand for the thermal power plant to achieve the secondary frequency function during load changes always cause the main stream temperature fluctuations, this paper introduces the metal temperature of water wall feed-forward control based on fuzzy control to optimize fuel- water ratio, the temperature of export dividing panel and the temperature of the high temperature super-heater feed-forward control based on fuzzy control to optimize the water temperature reduction. On the other hand introduced by constant pressure- sliding pressure- constant pressure composite operation mode, the sliding pressure is set up to multivariate constraints, using rules to correct it. This paper solve the problem of strong coupling pressure and load. The actual data and curves show that the optimization has the very good effect.