CN-115833180-B - Variable-speed hydroelectric generating set primary frequency modulation method and system based on fixed rotating speed of generating set

CN115833180BCN 115833180 BCN115833180 BCN 115833180BCN-115833180-B

Abstract

The invention discloses a variable speed hydroelectric generating set primary frequency modulation method based on fixed rotating speed of a generating set, which comprises the steps of obtaining real-time operating parameters and generating set parameters of the generating set, calculating electromagnetic power variation by a converter according to target electromagnetic power, calculating first opening control quantity and second opening control quantity of the generating set, controlling a mechanical hydraulic system in the generating set by a computer, inputting the controlling quantity of the mechanical hydraulic system into the mechanical hydraulic control system to obtain mechanical power variation, and completing primary frequency modulation of the target variable speed hydroelectric generating set according to the electromagnetic power variation and the mechanical power variation. The invention also discloses a system for realizing the variable speed hydroelectric generating set primary frequency modulation method based on the fixed rotating speed of the generating set. The invention adjusts the running rotating speed of the unit according to the target power value, not only realizes the primary frequency modulation of the variable speed hydroelectric unit based on the fixed rotating speed of the unit, but also has high reliability, good stability and better effect.

Inventors

KOU PANGAO

Assignees

国网湖南省电力有限公司
国网湖南省电力有限公司电力科学研究院
国家电网有限公司

Dates

Publication Date: 20260512
Application Date: 20221220

Claims (3)

1. A variable speed hydroelectric generating set primary frequency modulation method based on fixed rotating speed of a generating set comprises the following steps: acquiring real-time operation parameters and unit parameters of a target variable-speed hydroelectric unit; calculating an electromagnetic power variation corresponding to the primary frequency modulation action according to the target electromagnetic power by using a converter of the target variable speed hydroelectric generating set; according to the obtained parameter information, calculating to obtain a first opening control amount of the target variable speed hydroelectric generating set, wherein the method specifically comprises the following steps: obtaining measured frequency of power grid And reference frequency of the electric network ; The frequency value to be acquired And Subtracting to obtain frequency difference And the frequency difference value is passed through a dead zone link set by human Obtaining the frequency control quantity Is that Dead zone link The calculation formula of (2) is ; Controlling the frequency The first opening control quantity of the target variable speed hydroelectric generating set is obtained through a proportion link Is that Wherein, the method comprises the steps of, Is a proportionality coefficient of a proportionality link and is set as , The power permanent state interpolation coefficient of the target variable speed hydroelectric generating set is obtained; According to the acquired parameter information, the second opening control amount of the target variable speed hydroelectric generating set is calculated by combining the comprehensive characteristic curve data of the target variable speed hydroelectric generating set, and the method specifically comprises the following steps: obtaining target electromagnetic power And the current head of the target variable speed hydroelectric generating set ; Power calculation formula according to target variable speed hydroelectric generating set Calculating to obtain intermediate variable Then according to the comprehensive characteristic curve of the target variable speed hydroelectric generating set Calculating to obtain a basic opening control amount Wherein, the method comprises the steps of, To target the power of the water turbine in the variable speed hydroelectric generating set, For the weight of the water to be high, Is the diameter of the rotating wheel of the water turbine, To target the unit flow of the water turbine in the variable speed hydroelectric generating set, To target the efficiency of the water turbine in the variable speed hydroelectric generating set, For the opening degree of the guide vane of the water turbine in the target variable speed hydroelectric generating set, The unit rotating speed of a water turbine in the target variable speed hydroelectric generating set is set; the obtained basic opening control amount Processing through a proportion link to obtain a second opening control quantity of the target variable speed hydroelectric generating set Is that , Is a proportionality coefficient of a proportionality link and is set as , The maximum guide vane opening degree of the target variable speed hydroelectric generating set; according to the obtained first opening control amount and second opening control amount, calculating to obtain the control amount of a mechanical hydraulic system in the variable speed hydroelectric generating set, wherein the method specifically comprises the following steps: first opening control amount of target variable speed hydroelectric generating set And a second opening control amount of the target variable speed hydroelectric generating set Adding and subtracting the per unit value of the servomotor stroke of the target variable speed hydroelectric generating set Obtaining the opening control amount Is that ; Control of opening degree After passing through the PID controller, obtaining the control quantity of a mechanical hydraulic system in the variable-speed hydroelectric generating set; Inputting the obtained control quantity of the mechanical hydraulic system into the mechanical hydraulic control system to obtain a corresponding mechanical power variation quantity; and finishing the primary frequency modulation of the target variable speed hydroelectric generating set according to the obtained electromagnetic power variation and the mechanical power variation.
2. The variable speed hydroelectric generating set primary frequency modulation method based on set rotation speed fixation according to claim 1, wherein the set rotation speed of the target variable speed hydroelectric generating set is fixed at the optimal target rotation speed under the current water head and the current power.
3. A system for realizing the variable speed hydroelectric generating set primary frequency modulation method based on fixed rotating speed of the generating set according to claim 1 or 2, which is characterized by comprising a parameter acquisition module, an electromagnetic power variation calculation module, a first opening control amount calculation module, a second opening control amount calculation module, a mechanical hydraulic system control amount calculation module, a mechanical power variation calculation module and a primary frequency modulation module; the output end of the parameter acquisition module is connected with the input end of the electromagnetic power variation calculation module, the input end of the first opening control amount calculation module and the input end of the second opening control amount calculation module at the same time, the output end of the first opening control amount calculation module and the output end of the second opening control amount calculation module are connected with the input end of the mechanical hydraulic system control amount calculation module, the output end of the mechanical hydraulic system control amount calculation module, the mechanical power variation calculation module and the first input end of the primary frequency modulation module are sequentially connected in series, the output end of the electromagnetic power variation calculation module is connected with the second input end of the primary frequency modulation module, the output end of the primary frequency modulation module is connected with an external variable speed hydroelectric generating unit, the parameter acquisition module is used for acquiring real-time operation parameters and unit parameters of the target variable speed hydroelectric generating unit and uploading the data to the electromagnetic power variation calculation module, the first opening control amount calculation module and the second opening control amount calculation module are used for calculating corresponding electromagnetic power variation according to the acquired data according to the target electromagnetic power, the primary frequency modulation action is acquired according to the acquired data of the target variable speed hydroelectric generating unit, the system comprises a first opening control amount calculation module, a second opening control amount calculation module, a mechanical hydraulic system control amount calculation module, a mechanical power change amount calculation module and a primary frequency modulation module, wherein the first opening control amount calculation module is used for calculating and obtaining the mechanical hydraulic system control amount in the variable speed hydroelectric generating set according to acquired data by combining comprehensive characteristic curve data of the target variable speed hydroelectric generating set, the second opening control amount calculation module is used for calculating and obtaining the second opening control amount of the target variable speed hydroelectric generating set according to the acquired data, the data is uploaded to the mechanical hydraulic system control amount calculation module, the mechanical power change amount calculation module is used for inputting the obtained mechanical hydraulic system control amount into the mechanical hydraulic control system according to the acquired data to obtain corresponding mechanical power change amount, and the primary frequency modulation module is used for completing primary frequency modulation of the target variable speed hydroelectric generating set according to the acquired data.

Description

Variable-speed hydroelectric generating set primary frequency modulation method and system based on fixed rotating speed of generating set Technical Field The invention belongs to the technical field of unit control, and particularly relates to a variable speed hydroelectric unit primary frequency modulation method and system based on unit rotation speed fixation. Background Along with the development of economic technology and the improvement of living standard of people, electric energy becomes an indispensable secondary energy source in the production and living of people, and brings endless convenience to the production and living of people. Therefore, ensuring stable and reliable supply of electric energy becomes one of the most important tasks of the electric power system. Currently, as more and more new energy power generation systems are incorporated into the power grid, the uncertainty of the output of the new energy power generation systems makes the power system face unprecedented operating pressures. The pumped storage power station has very excellent peak regulation and frequency modulation capability, and is one of important modes of peak regulation and frequency modulation of a power system. Therefore, the primary frequency modulation control of the unit of the pumped storage power station is particularly important. At present, the conventional hydroelectric power unit or constant-speed pumped storage power unit is generally adopted as the unit of the pumped storage power station. However, such units are very difficult to operate below 40% rated load due to the influence of vibration area, pressure pulsation and other reasons, and the efficiency is significantly reduced when the units deviate from the designed working point. As a result, the conventional pumped-storage power station units have gradually begun to be unsuitable for use in today's electrical power systems. The variable-speed hydroelectric generating set has the advantages of wide operating range, large adjustable range of set power, high operating efficiency under steady-state operating conditions of the set and the like, and is considered as a future first-choice set of the pumped storage power station. However, if the variable-speed hydroelectric generating set is subjected to primary frequency modulation by adopting a primary frequency modulation method of a traditional pumped storage power station, the problems of slow primary frequency modulation response, serious servomotor abrasion, deviation of the running working condition of the generating set from a high-efficiency area and the like exist. Disclosure of Invention The invention aims to provide a variable speed hydroelectric generating set primary frequency modulation method based on fixed rotating speed of a generating set, which is high in reliability, good in stability and good in effect. The second purpose of the invention is to provide a system for realizing the variable speed hydroelectric generating set primary frequency modulation method based on the fixed rotating speed of the generating set. The primary frequency modulation method of the variable speed hydroelectric generating set based on fixed rotating speed of the generating set provided by the invention comprises the following steps: acquiring real-time operation parameters and unit parameters of a target variable-speed hydroelectric unit; calculating an electromagnetic power variation corresponding to the primary frequency modulation action according to the target electromagnetic power by using a converter of the target variable speed hydroelectric generating set; Calculating a first opening control amount of the target variable speed hydroelectric generating set according to the acquired parameter information; Calculating a second opening control amount of the target variable speed hydroelectric generating set according to the acquired parameter information and by combining comprehensive characteristic curve data of the target variable speed hydroelectric generating set; Calculating the control quantity of a mechanical hydraulic system in the variable speed hydroelectric generating set according to the obtained first opening control quantity and second opening control quantity; Inputting the obtained control quantity of the mechanical hydraulic system into the mechanical hydraulic control system to obtain a corresponding mechanical power variation quantity; and finishing the primary frequency modulation of the target variable speed hydroelectric generating set according to the obtained electromagnetic power variation and the mechanical power variation. In the above steps, the unit rotational speed of the target variable speed hydroelectric unit is fixed at the optimum target rotational speed at the current head and current power. The step of calculating the first opening control amount of the target variable speed hydroelectric generating set according to the acquired parameter information specifically c