Supercritical unit CCS side primary frequency modulation method

Abstract

The invention discloses a supercritical unit CCS side primary frequency modulation method. The method comprises the following steps: 1, the sum of an AGC power instruction and a primary frequency modulation power change requirement value is solved; 2, the sum value acquired in the first step and a power lower limit value are compared, and the larger value between the two is taken; and 3, the larger value acquired in the second step and a power upper limit value are compared, and the smaller value between the two is taken as power instruction output. Thus, the unit primary frequency modulation function can achieve long-term safety input, the unit primary frequency modulation performance is excellent, an important role is played in safety and reliability of a power grid and a power plant, frequency modulation requirements by the power grid can be fully met, and on the above premise, speed control system modeling work of the unit of the kind can be developed smoothly.

Description

technical field [0001] The invention relates to the field of steam turbine regulation systems, in particular to a primary frequency regulation method on the CCS side of a supercritical unit. Background technique [0002] The grid frequency is the basis for the balance between power generation and load. When the power generation is equal to the load, the frequency of the grid is stable; when the power is greater than the load, the frequency of the grid rises; Reduced frequency. [0003] Primary frequency regulation refers to an automatic control process in which once the frequency of the grid deviates from the rated value, the control system of the unit in the grid will automatically control the increase or decrease of the active power of the unit, limit the change of the grid frequency, and maintain the stability of the grid frequency. When the frequency of the power grid increases, the primary frequency regulation function requires the unit to use its heat storage to quick...

AI Technical Summary

Problems solved by technology

[0011] The performance of the coordinated control system is not good. The primary frequency regulation function is an important function upstream of the coordinated control system. A coordinated control system with excellent performance is undoubtedly the basis for the optimization of primary frequency regulation. Many units have poor performance of the primary frequency regulation function because of the performance of the coordinated control system. Poor; the speed measurement is incorrect. The turbine speed is theoretically consistent with the grid frequency, but there is a certain delay. The turbine speed fluctuates, causing the turbine adjustment door to shake, the unit operation stability decreases, and the primary frequency modulation performance is poor; the frequency signal should be checked by the entire network , frequency signal, and there is a certain delay and fluctuation; the heat storage of the DC furnace is small, and the primary frequency modulation cannot be sustained. When the primary frequency modulation is inconsistent with the AGC change direction, the performance will deteriorate. There is a phenomenon of reverse regulation in the system; there is a deviation between the DEH door adjustment command and the power, and the correctness of the primary frequency regulation is not enough; at present, many units are operated by sliding pressure, and the steam turbine door is kept at a large opening, and the performance of primary frequency regulation is poor. The linearity is not good, the unit is running close to full load, the frequency regulation performance is poor when the control door is almost fully opened, and the performance is not good when the grid frequency changes slightly; the supercritical unit does not have heat storage like a drum furnace, so the power of the unit changes when the control door changes Very small, and the steam pressure changes greatly, which cannot meet the initial load changing requirements of the power grid

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