CN-116979554-B - Control method for primary frequency modulation in thermal power generating unit

CN116979554BCN 116979554 BCN116979554 BCN 116979554BCN-116979554-B

Abstract

The embodiment of the application discloses a control method for primary frequency modulation in a thermal power generating unit. The method comprises the steps of determining a control mode of primary frequency modulation after receiving primary frequency modulation control information, obtaining a correction strategy of the control mode, correcting an action value corresponding to the primary frequency modulation control information according to the correction strategy, and executing primary frequency modulation operation according to the corrected primary frequency modulation action value.

Inventors

YANG CHENG
NIU HAIMING
YE QING
ZENG FANFEI
Qi Xiangbai
CAI YONG

Assignees

国能智深控制技术有限公司
国能蚌埠发电有限公司

Dates

Publication Date: 20260505
Application Date: 20220422

Claims (9)

1. A control method of primary frequency modulation in a thermal power generating unit comprises the following steps: After receiving the primary frequency modulation control information, determining a primary frequency modulation control mode; Acquiring a correction strategy of the control mode; Correcting the action value corresponding to the primary frequency modulation control information according to the correction strategy; executing primary frequency modulation operation according to the corrected primary frequency modulation action value; The correcting the action value corresponding to the primary frequency modulation control information according to the correction strategy includes: if the control mode is an adjustment level pressure mode, calculating a first ratio of a primary frequency modulation action power value to a rated power value of the unit; calculating a first difference value between a rated main steam pressure value and a flushing rated main steam pressure value, and calculating a product of the first ratio value and the first difference value to obtain a corrected action value, wherein the adjustment direction of the corrected action value is reverse; If the control mode is a coordination control system CCS mode or an open loop control mode, acquiring correction information of a primary frequency modulation feedforward action value, wherein the correction information comprises a main steam pressure value, a load value of active power and a comprehensive valve position value, calculating the product of the correction information and a primary frequency modulation action power value to obtain a corrected primary frequency modulation feedforward action value, and obtaining the corrected primary frequency modulation action value according to the corrected primary frequency modulation feedforward action value.
2. The method according to claim 1, wherein the method further comprises: Judging whether the control mode is a power closed-loop control method or not; and if the control mode is not the power closed-loop control, acquiring a correction strategy of the control mode.
3. The method of claim 1, wherein the obtaining correction information for the primary frequency modulation feedforward action value comprises: Respectively acquiring real-time values of respective correction parameters of a current main steam pressure value, a current active power load value and a current comprehensive valve position value by utilizing a prestored correction function; And calculating the product of the real-time values of all the correction parameters to obtain correction information.
4. A method according to claim 3, characterized in that the method further comprises: setting the maximum values of the correction parameters of the main steam pressure value, the load value of the active power and the comprehensive valve position value respectively, wherein the larger the value of the main steam pressure value is, the smaller the maximum value of the correction parameter is, and the maximum values of the correction parameters of the active power and the comprehensive valve position value are smaller than or equal to 1; and comparing the real-time value of the correction parameter with the maximum value of the corresponding correction parameter when the real-time value of the correction parameter is obtained, and allowing the calculation of correction information to be performed smaller than the maximum value of the correction parameter.
5. A method according to claim 3, characterized in that after obtaining the real-time values of all correction parameters, the method further comprises: And locking the real-time values of all the correction parameters, and recalculating the value of each correction parameter when the next frequency modulation operation is executed.
6. The method according to claim 1, wherein the method further comprises: when the control loop in the working state is switched from the first control loop to the second control loop, calculating a difference value between a tracking value of the first control loop and a primary frequency modulation action value currently used by the first control loop to obtain a second difference value; And after the first control loop is switched again, executing primary frequency modulation operation of the first control loop according to the second difference value.
7. The method according to claim 1, wherein the method further comprises: When the control mode is a Coordination Control System (CCS) mode or an open loop control mode, if the received load instruction comprises primary frequency modulation control information, judging whether the load instruction is a load instruction acting on a valve position base line, and obtaining a judging result; if the judging result is a load instruction applied to the valve position base line, deleting primary frequency modulation control information from the load instruction to obtain a new load instruction; and executing the new load instruction.
8. A storage medium having a computer program stored therein, wherein the computer program is arranged to perform the method of any of claims 1 to 7 when run.
9. An electronic device comprising a memory and a processor, characterized in that the memory has stored therein a computer program, the processor being arranged to run the computer program to perform the method of any of the claims 1 to 7.

Description

Control method for primary frequency modulation in thermal power generating unit Technical Field The embodiment of the application relates to the field of information processing, in particular to a control method for primary frequency modulation in a thermal power generating unit. Background The primary frequency modulation function of the unit refers to a function that when the frequency of a power grid exceeds a specified normal range, the speed regulation system of each unit participating in primary frequency modulation in the power grid automatically increases or decreases the power of the unit according to the change of the frequency of the power grid, so that new balance is achieved, and the change of the frequency of the power grid is limited within a certain range. The primary frequency modulation function is an important means for maintaining the stability of the power grid, and compared with other frequency modulation means, the primary frequency modulation function is characterized by rapidity, and when the power grid frequency exceeds an action dead zone, the primary frequency modulation can act for the first time to perform rapid response and adjustment. Meanwhile, the primary frequency modulation also has certain amplitude limiting, and after all, the disturbance of the quick response to the power supply side is larger. Along with the transition of the age and the development of technology, the targets of carbon neutralization and carbon peak achievement are put forward, the electric power structure is continuously changed, the duty ratio of new energy is continuously improved, the duty ratio of thermal power is gradually reduced, the environmental protection low-carbon index is improved, the interference factor of the power grid frequency is increased, and higher requirements are put forward for the stability of the power grid frequency. The characteristics of the thermal power generating unit determine that the frequency modulation and peak regulation effects of the thermal power generating unit cannot be replaced in a short period, and especially for primary frequency modulation, new energy cannot be adjusted upwards, and energy loss can be caused by downward adjustment, so that the primary frequency modulation of the thermal power generating unit is very important. The requirements of the power grid on the thermal power generating unit are different, but the requirements on primary frequency modulation are clear, and a corresponding rewarding and checking mechanism is also provided. The judgment of the primary frequency modulation index is based on response time, action amplitude and integral electric quantity, wherein the response time requires that the active power of the thermal power unit is required to be changed in a correct direction within a specified time, the action amplitude requires that the power change amount within the specified time reaches a certain value, and the integral electric quantity is the generated energy of the unit increased or decreased within a certain range within the whole primary frequency modulation time. The advantages and disadvantages of the primary frequency modulation indexes of each thermal power plant can also directly influence the economic benefit of the power plant, and the traditional primary frequency modulation mode can not meet the requirements gradually, so that on the basis of safe and stable operation of the unit, the research on the optimization scheme capable of effectively improving the primary frequency modulation of the unit is of great significance. In the related art, the primary frequency modulation strategy of the thermal power plant is as follows: 1. And generating a primary frequency modulation action function F (x) according to the primary frequency modulation action dead zone, the primary frequency modulation action limit value and the rotation speed unequal rate required by the power grid. 2. And superposing the generated primary frequency modulation action function to the front of a turbine main control PID of a DCS coordination system of the distributed control system, and superposing the function to an open loop and a power closed loop of the DEH (DIGITAL ELECTRIC-Hydraulic, digital electrohydraulic) side. 3. When the primary frequency modulation index is poor, the corresponding time of the primary frequency modulation can reach the standard usually due to the feedforward effect on the DEH side, and the action amplitude and the integral electric quantity index are poor in most cases, and then the primary frequency modulation action function on the DEH side can be adjusted to improve the corresponding index. In practical applications, the implementation of the frequency modulation strategy is simple, but has a plurality of disadvantages. The thermal power unit is complex in regulation, factors influencing the power of the unit are many, effects generated under different working conditions are different by simply modifying a