Online detection method and system for primary frequency modulation of hydraulic power plant

Abstract

The invention relates to the technical field of power system monitoring and control, and discloses a primary frequency modulation online detection method and system for a hydraulic power plant, and the method comprises the steps: reading primary frequency modulation configuration parameters of a hydraulic power plant unit, and judging whether a primary frequency modulation event occurs in the hydraulic power plant unit; the method comprises the following steps: acquiring and monitoring frequency data and active output data of a hydraulic power plant unit in real time through a wide-area measurement system, judging whether the hydraulic power plant unit meets a primary frequency modulation grabbing condition or not, and confirming a grid-connected state of the hydraulic power plant unit; and based on the grid-connected state of the hydraulic power plant unit, calculating a performance assessment index of the unit. By introducing a wide area measurement system (WAMS) and a real-time data processing technology, high-precision real-time detection of the primary frequency modulation event of the hydraulic power plant unit is realized. Compared with a traditional method, the method has the advantages that the data acquisition precision and the monitoring response speed are remarkably improved, whether the hydroelectric generating set meets the frequency modulation grabbing condition or not can be quickly judged when frequency disturbance occurs, and the performance assessment index of the hydroelectric generating set is evaluated in real time.

Description

Technical Field

[0001] The present invention relates to the technical field of power system monitoring and control, and in particular to an online detection method and system for primary frequency modulation of a hydropower plant. Background Art

[0002] With the continuous development and expansion of the power system, ensuring the stability of the power grid and the safety of power supply has become one of the core tasks in the operation of modern power systems. Primary Frequency Control (PFC), as an important technology to ensure the stability of the power grid, plays a key role in quickly responding to and adjusting frequency deviations. In this process, hydropower plants occupy a vital position in power grid frequency regulation due to their faster response time and greater regulation capabilities. In recent years, with the improvement of the automation level of power systems, the application of wide area measurement systems (WAMS) and phasor measurement units (PMUs) has provided more accurate and real-time data support for the detection of the frequency regulation capabilities of hydropower plants. Through these high-precision monitoring equipment, the operating status of the power system can be monitored in real time, and timely adjustment measures can be taken when frequency deviations occur, thereby improving the reliability and stability of the power grid.

[0003] However, there are still some limitations in the monitoring and evaluation of primary frequency regulation capabilities in the existing technology. Traditional frequency regulation detection methods mostly rely on local measurement equipment and manual analysis, and their detection accuracy and response speed are relatively low. At the same time, in the existing technology, the determination of the primary frequency regulation event of the unit is often based on offline data and manually set thresholds, lacking real-time and flexibility, resulting in an inability to respond quickly when frequency disturbances occur. In addition, the real-time calculation of the grid-connected status and performance evaluation indicators of the hydropower unit is often limited by the data collection method and processing algorithm, and it is impossible to provide timely and accurate performance evaluation during the grid dispatch process. These problems limit the scope of application of existing frequency regulation detection systems, especially in large-scale hydropower plants and complex power grid environments. Summary of the invention

[0004] In view of the above-mentioned problems, the present invention is proposed.

[0005] Therefore, the technical problem solved by the present invention is: the problems of low data acquisition accuracy, long response time and delayed performance evaluation in the existing primary frequency modulation detection system.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: a method for online detection of primary frequency regulation in a hydropower plant, comprising:

[0007] Read the primary frequency regulation configuration parameters of the hydropower plant units to determine whether a primary frequency regulation event occurs in the hydropower units;

[0008] The wide-area measurement system collects and monitors the frequency data and active output data of the hydropower plant units in real time, determines whether the hydropower plant units meet the primary frequency regulation capture conditions, and confirms the grid-connected status of the hydropower plant units;

[0009] Performance evaluation indicators of the computer group after the hydropower plant units are connected to the grid.

[0010] As a preferred solution of the primary frequency regulation online detection method of the hydropower plant described in the present invention, wherein: the primary frequency regulation configuration parameters include frequency regulation dead zone, minimum duration, maximum duration, effective disturbance amplitude, steady-state time before frequency regulation, frequency regulation response time, unit grid-connected power threshold, frequency capture condition, frequency regulation exit standard and frequency regulation performance evaluation standard;

[0011] Determining whether a frequency regulation event occurs in a hydropower unit includes determining whether the frequency of the power grid where the hydropower unit is located exceeds the frequency regulation dead zone, and whether the deviation duration exceeds the minimum duration requirement of the frequency regulation event;

[0012] Determine whether the interval between the current frequency modulation event and the previous frequency modulation event meets the effective disturbance interval.

[0013] As a preferred solution of the method for online detection of primary frequency regulation of a hydropower plant described in the present invention, the frequency data of the hydropower plant units include real-time frequency, frequency deviation, frequency change rate and frequency disturbance events;

[0014] The active output data of the hydropower plant units include the active output of the units, the output variation of the units, the steady combustion load of the units, the maximum adjustable active output of the units and the minimum adjustable active output of the units;

[0015] The determination of whether the hydropower plant unit meets the primary frequency regulation capture condition includes, when a hydropower unit has a primary frequency regulation event, performing frequency deviation determination, duration determination, frequency amplitude determination, grid connection state determination, pre-frequency regulation steady state determination, frequency regulation state determination, and disturbance interval determination;

[0016] The frequency deviation judgment includes judging whether the frequency of the power grid where the hydropower unit is located exceeds the primary frequency regulation dead zone;

[0017] The duration determination includes determining whether the frequency deviation continues for more than a set time;

[0018] The frequency amplitude determination includes checking whether the disturbance amplitude exceeds a preset effective disturbance threshold frequency disturbance amplitude;

[0019] The grid-connected status judgment includes judging whether the active output of the unit exceeds the grid-connected power threshold;

[0020] The steady-state judgment before frequency modulation includes confirming whether the frequency is stable to avoid misjudgment;

[0021] The frequency modulation state judgment includes checking the frequency modulation input / output signal of the unit to judge whether the unit is in the frequency modulation participation state;

[0022] The disturbance interval determination includes ensuring whether the intervals between multiple frequency modulation events conform to the effective disturbance interval.

[0023] As a preferred solution of the method for online detection of primary frequency regulation of a hydropower plant according to the present invention, the method of confirming the grid-connected status of a hydropower plant unit includes active output inspection, grid-connected and off-grid status determination of the unit, steady-burning load determination, frequency regulation status determination, unit control signal determination and unit historical status inspection;

[0024] The active output check includes checking whether the active output of the hydropower plant unit is greater than the set grid-connected power threshold, and determining whether the time when the active output is less than the grid-connected power threshold continues to exceed the set time;

[0025] The determination of the unit's grid-connected and off-grid status includes: when the unit's active output exceeds the grid-connected power threshold and the duration meets the requirements, the unit is determined to be in the grid-connected state and can participate in a frequency modulation;

[0026] When the active output of the unit is lower than the grid-connected power threshold and the duration exceeds the set value, the unit is judged to be off-grid and cannot participate in frequency regulation;

[0027] The stable combustion load judgment includes whether the unit is maintained within the stable load range to ensure that the unit will not be disconnected from the grid due to too low load;

[0028] The frequency modulation state judgment includes confirming whether the unit participates in the frequency modulation operation;

[0029] The unit control signal includes confirming whether the hydropower plant unit has received a frequency modulation control signal. When the unit has not received a frequency modulation signal or the frequency modulation signal is 0, it is determined that the unit is not involved in the frequency modulation;

[0030] The unit historical status check includes confirming whether the unit is normal based on the unit historical data and control records.

[0031] As a preferred solution of the on-line detection method for primary frequency regulation of a hydropower plant described in the present invention, the performance evaluation index of the unit includes the actual integrated power. When the system frequency deviation exceeds the specified range, the statistical program is automatically started, and the average output P of the unit's primary frequency regulation dead zone two seconds before the dead zone is calculated. o As the base point, integrate the power generation change backward until the system frequency returns to within the unit action dead zone. The formula is expressed as:

[0032] Among them, P trepresents the actual power at time t; t o represents the time when the system frequency exceeds the dead zone of the primary frequency regulation of unit i, t represents the time when the system frequency enters the dead zone of the primary frequency regulation of unit i, P o It indicates the average output of the unit two seconds before the dead zone point of the primary frequency regulation.

[0033] As a preferred solution of the on-line detection method for primary frequency regulation of a hydropower plant described in the present invention, the performance evaluation index of the unit also includes a theoretical integral power, and the theoretical primary frequency regulation integral power H of unit i is e The formula is expressed as:

[0034] ΔP(Δf,t)=Δf(t)×MCR 2 / 2f n ×K c

[0035] Where Δf(t) represents the frequency difference corresponding to the grid frequency change exceeding the dead zone, MCR represents the rated active output of the unit, and f n Indicates the system rated frequency, K c Indicates the speed change rate of the corresponding unit.

[0036] As a preferred solution of the primary frequency regulation online detection method of the hydropower plant described in the present invention, the performance evaluation indicators of the unit also include power contribution rate, primary frequency regulation monthly operation rate, frequency regulation qualification judgment and stabilization time;

[0037] The power contribution ratio is actual power contribution / theoretical power contribution;

[0038] The monthly commissioning rate of primary frequency regulation is monthly commissioning time / grid connection time;

[0039] Among them, the grid-connected time refers to the operating time when the active power of the unit is greater than the set threshold; the monthly input time refers to the operating time when the unit is judged to be grid-connected and its primary frequency regulation input and output state is input;

[0040] The frequency modulation qualification judgment includes: when the value of the primary frequency modulation power contribution rate is greater than the set qualified threshold, the frequency modulation is qualified; when the value of the primary frequency modulation power contribution rate is less than the set qualified threshold, the primary frequency modulation is unqualified;

[0041] The stabilization time includes the time from the start of the unit's active extreme value time to the end of frequency modulation, during which the active power reaches a stable state.

[0042] An online detection system for primary frequency regulation of a hydropower plant, wherein:

[0043] The frequency modulation module is used to read the primary frequency modulation configuration parameters of the hydropower plant units and determine whether a primary frequency modulation event occurs in the hydropower units;

[0044] The data monitoring module collects and monitors the frequency data and active output data of the hydropower plant units in real time through the wide-area measurement system, determines whether the hydropower plant units meet the primary frequency regulation capture conditions, and confirms the grid-connected status of the hydropower plant units;

[0045] Performance calculation module, performance evaluation indicators of the computer group after the hydropower plant units are connected to the grid.

[0046] A computer device comprises: a memory and a processor; the memory stores a computer program, wherein the processor implements the steps of any one of the methods of the present invention when executing the computer program.

[0047] A computer-readable storage medium stores a computer program, wherein the computer program, when executed by a processor, implements the steps of any one of the methods of the present invention.

[0048] Beneficial effects of the present invention: The method for online detection of primary frequency regulation of a hydropower plant provided by the present invention realizes high-precision real-time detection of primary frequency regulation events of hydropower plant units by introducing a wide area measurement system (WAMS) and real-time data processing technology. Compared with traditional methods, the present invention significantly improves the accuracy of data acquisition and the response speed of monitoring, and can quickly determine whether the hydropower unit meets the frequency regulation capture conditions when a frequency disturbance occurs, and evaluate the performance evaluation indicators of the unit in real time. It not only improves the detection accuracy of the frequency regulation capability of the hydropower plant, but also optimizes the grid dispatching decision and improves the stability and reliability of the grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0050] Figure 1 An overall flow chart of an online detection method for primary frequency regulation in a hydropower plant provided by the first embodiment of the present invention;

[0051] Figure 2 A system structure diagram of a method for online detection of primary frequency regulation in a hydropower plant provided by the first embodiment of the present invention;

[0052] Figure 3 A flow chart of detection calculation of an online detection method for primary frequency regulation of a hydropower plant provided in the first embodiment of the present invention. DETAILED DESCRIPTION

[0053] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0054] Example 1, reference Figure 1 , as an embodiment of the present invention, provides an online detection method for primary frequency regulation of a hydropower plant, comprising:

[0055] S1: Read the primary frequency regulation configuration parameters of the hydropower plant units to determine whether a primary frequency regulation event occurs in the hydropower units.

[0056] The primary frequency regulation configuration parameters include frequency regulation dead zone, minimum duration, maximum duration, effective disturbance amplitude, steady-state time before frequency regulation, frequency regulation response time, unit grid-connected power threshold, frequency capture conditions, frequency regulation exit criteria and frequency regulation performance evaluation criteria.

[0057] The system structure diagram of the primary frequency modulation online detection system is as follows: Figure 2 As shown, the system includes a real-time detection program (server) and a human-machine interface (workstation).

[0058] The above-mentioned real-time detection program includes a primary frequency regulation event detection and index calculation module; a PMU fault detection module; a unit connection and primary frequency regulation time statistics module. The primary frequency regulation event detection and index calculation module uses the WAMS time series real-time library data to detect frequency disturbance events in real-time online detection to determine whether the selected station frequency meets the primary frequency regulation detection conditions. When the conditions are met, the performance indicators of the generator sets participating in the primary frequency regulation performance assessment will be calculated. And the calculation results will be written into the WAMS commercial library. The above-mentioned performance indicators include: the actual contribution of primary frequency regulation, the theoretical contribution of primary frequency regulation, the contribution rate of primary frequency regulation, the actual contribution of primary frequency regulation in 15 seconds (30 seconds / 45 seconds / 60 seconds), the theoretical contribution of primary frequency regulation in 15 seconds (30 seconds / 45 seconds / 60 seconds), the contribution rate of primary frequency regulation in 15 seconds (30 seconds / 45 seconds / 60 seconds), the response lag time, the adjustment amplitude, the adjustment deviation, the speed change rate, the actual maximum active power adjustment, the theoretical maximum active power adjustment, etc. When the number of real-time data read by the PMU fault detection module is 0 or all are invalid numbers, if this time period exceeds the PMU fault tolerance threshold (60s, which can be set through the "Parameter Setting" interface), the unit status will be set to: "PMU fault". Before the PMU fault, the unit was off-grid or the primary frequency modulation start-up and stop signal was exited, and the program will continue the previous state. The unit start-up and primary frequency modulation start-up and stop time statistics module continuously monitors the active output data of the unit. When the active output of the unit is less than a threshold (the unit grid-connected power threshold, which can be set) and lasts for a period of time (the default is 5s, which can be set), the unit is considered to be off-grid, otherwise it is grid-connected; if the active output of the unit is above the unit's stable combustion load (i.e., the lower limit of the load), the primary frequency modulation start-up and stop signal is 0, and it lasts for a period of time (the default is 300s, which can be set), the unit is considered to be exited by the primary frequency modulation, otherwise it is put into the primary frequency modulation.

[0059] The above-mentioned human-machine interface includes a real-time monitoring window for unit data, a frequency modulation curve viewing window, an assessment statistics and result display window, an assessment-free setting window, and a parameter setting window. The real-time monitoring window for the unit can intuitively display the types of generators in the area (thermal power, hydropower, nuclear power, etc.), the primary frequency modulation drop-in and drop-out status, the primary frequency modulation action status, the PMU working status, the power output and frequency information. The frequency modulation curve viewing window can read the historical data of each unit (including frequency, theoretical output, actual output, etc.) and display it in the form of a curve. And display the corresponding primary frequency modulation data indicators. The assessment statistics and result display window can count and assess the single / monthly frequency modulation operation status of a single machine / the entire network. The parameter design interface can modify the relevant parameters used in the detection program or interface, and can also modify the constraints of the generator set being detected.

[0060] Determining whether a frequency regulation event occurs in a hydropower unit includes determining whether the frequency of the power grid where the hydropower unit is located exceeds the frequency regulation dead zone, and whether the deviation duration exceeds the minimum duration requirement of the frequency regulation event;

[0061] Determine whether the interval between the current frequency modulation event and the previous frequency modulation event meets the effective disturbance interval.

[0062] The flow chart of the primary frequency modulation online detection calculation is as follows Figure 3 As shown, the process implementation steps are as follows:

[0063] (1) Read the parameters of table 8128 to determine the configuration parameters; read the plant station, generator set, and station frequency information of table 411 / 8219 / 8130 / 8312 to complete the reading of the unit's primary frequency regulation configuration parameters, which are used to determine whether the unit has a primary frequency regulation event.

[0064] (2) The wide area measurement system WAMS time series real-time library data is used to detect the frequency of each unit, and whether the unit meets the primary frequency regulation capture conditions is determined based on whether the unit frequency meets the corresponding unit primary frequency regulation configuration parameters.

[0065] (3) After determining that the unit meets the primary frequency modulation capture conditions, the wide area measurement system WAMS time series real-time library data is used to detect the active output of each unit, and whether the unit is connected to the grid is determined based on whether the active output of the unit meets the corresponding unit grid-connected power threshold configuration parameters.

[0066] (4) After the unit is connected to the grid, the unit's active output is used to calculate the unit's contribution power, theoretical contribution power, contribution ratio and other primary frequency regulation performance assessment indicators, and the results are written into the commercial database.

[0067] (5) Determine whether a program end signal is issued. If not, return to step (2) and run in a loop.

[0068] A frequency modulation event needs to meet the following conditions:

[0069] (1) The frequency exceeds the value of the primary frequency regulation dead zone (0.033Hz, which can be set separately for different types of units, the same below), and the frequency is outside the primary frequency regulation dead zone value for at least 15 seconds (minimum integration time, which can be set) and no more than 60 seconds (maximum integration time, which can be set) as the frequency interval to be selected for the effective primary frequency regulation event.

[0070] (2) The maximum amplitude should exceed 50.0±0.035Hz (effective disturbance dead zone, which can be set) within 15 seconds (i.e. T2-T1<=15 ramp time, which can be set) from the time the frequency exceeds the frequency modulation dead zone once, and it should last for more than 2 seconds (T4-T2>=2 effective disturbance duration, which can be set).

[0071] (3) The frequency fluctuation within 5 seconds before the starting point of the effective disturbance frequency segment selected after meeting conditions (1) and (2) (the steady-state time before frequency modulation, which can be set) cannot exceed 50.0±0.033Hz.

[0072] (4) After 20 seconds (effective disturbance interval, which can be set) of this assessment, no more assessments will be taken.

[0073] S2: The frequency data and active output data of the hydropower plant units are collected and monitored in real time through the wide area measurement system to determine whether the hydropower plant units meet the primary frequency regulation capture conditions and confirm the grid-connected status of the hydropower plant units.

[0074] Frequency data of hydropower plant units include real-time frequency, frequency deviation, frequency change rate and frequency disturbance events;

[0075] The active output data of the hydropower plant units include the active output of the units, the output variation of the units, the steady combustion load of the units, the maximum adjustable active output of the units and the minimum adjustable active output of the units;

[0076] The determination of whether the hydropower plant unit meets the primary frequency regulation capture condition includes, when a hydropower unit has a primary frequency regulation event, performing frequency deviation determination, duration determination, frequency amplitude determination, grid connection state determination, pre-frequency regulation steady state determination, frequency regulation state determination, and disturbance interval determination;

[0077] The frequency deviation judgment includes judging whether the frequency of the power grid where the hydropower unit is located exceeds the primary frequency regulation dead zone;

[0078] The duration determination includes determining whether the frequency deviation continues for more than a set time;

[0079] The frequency amplitude determination includes checking whether the disturbance amplitude exceeds a preset effective disturbance threshold frequency disturbance amplitude;

[0080] The grid-connected status judgment includes judging whether the active output of the unit exceeds the grid-connected power threshold;

[0081] The steady-state judgment before frequency modulation includes confirming whether the frequency is stable to avoid misjudgment;

[0082] The frequency modulation state judgment includes checking the frequency modulation input / output signal of the unit to judge whether the unit is in the frequency modulation participation state;

[0083] The disturbance interval determination includes ensuring whether the intervals between multiple frequency modulation events conform to the effective disturbance interval.

[0084] Confirming the grid-connected status of the hydropower plant units includes active output inspection, grid-connected and off-grid status determination of the units, stable combustion load determination, frequency regulation status determination, unit control signal determination and unit historical status inspection;

[0085] The active output check includes checking whether the active output of the hydropower plant unit is greater than the set grid-connected power threshold, and determining whether the time when the active output is less than the grid-connected power threshold continues to exceed the set time;

[0086] The determination of the grid-connected and off-grid status of the unit includes: when the active output of the unit exceeds the grid-connected power threshold and the duration meets the requirements, the unit is determined to be in the grid-connected state and can participate in the primary frequency regulation;

[0087] When the active output of the unit is lower than the grid-connected power threshold and the duration exceeds the set value, the unit is judged to be off-grid and cannot participate in frequency regulation;

[0088] The stable combustion load judgment includes whether the unit is maintained within the stable load range to ensure that the unit will not be disconnected from the grid due to too low load;

[0089] The frequency modulation state judgment includes confirming whether the unit participates in the frequency modulation operation;

[0090] The unit control signal includes confirming whether the hydropower plant unit has received a frequency modulation control signal. When the unit has not received a frequency modulation signal or the frequency modulation signal is 0, it is determined that the unit is not involved in the frequency modulation;

[0091] The unit historical status check includes confirming whether the unit is normal based on the unit historical data and control records.

[0092] S3: Performance evaluation indicators of the computer group based on the grid-connected status of the hydropower plant units.

[0093] The performance evaluation indicators of the unit include the actual integrated power. When the system frequency deviation exceeds the specified range, the statistical program automatically starts, and the average output of the unit two seconds before the dead zone point of the frequency regulation is calculated. o As the base point, integrate the power generation change backward until the system frequency returns to within the unit action dead zone. The formula is expressed as:

[0094]

[0095] Among them, P t represents the actual power at time t; t orepresents the time when the system frequency exceeds the dead zone of the primary frequency regulation of unit i, t represents the time when the system frequency enters the dead zone of the primary frequency regulation of unit i, P o It indicates the average output of the unit two seconds before the dead zone point of the primary frequency regulation.

[0096] The performance evaluation index of the unit also includes the theoretical integral power, the theoretical primary frequency regulation integral power H of unit i e The formula is expressed as:

[0097]

[0098] ΔP(Δf,t)=Δf(t)×MCR 2 / 2f n ×K c

[0099] Where Δf(t) represents the frequency difference corresponding to the grid frequency change exceeding the dead zone, MCR represents the rated active output of the unit, and f n Indicates the system rated frequency, K c Indicates the speed change rate of the corresponding unit.

[0100] The performance evaluation indicators of the unit also include power contribution rate, monthly commissioning rate of primary frequency regulation, frequency regulation qualification judgment and stabilization time;

[0101] The power contribution ratio is actual power contribution / theoretical power contribution;

[0102] The monthly commissioning rate of primary frequency regulation is monthly commissioning time / grid connection time;

[0103] Among them, the grid-connected time refers to the operating time when the active power of the unit is greater than the set threshold; the monthly input time refers to the operating time when the unit is judged to be grid-connected and its primary frequency regulation input and output state is input;

[0104] The frequency modulation qualification judgment includes: when the value of the primary frequency modulation power contribution rate is greater than the set qualified threshold, the frequency modulation is qualified; when the value of the primary frequency modulation power contribution rate is less than the set qualified threshold, the primary frequency modulation is unqualified;

[0105] The stabilization time includes the time from the start of the unit's active extreme value time to the end of frequency modulation, during which the active power reaches a stable state.

[0106] Embodiment 2 is an embodiment of the present invention, which provides an online detection system for primary frequency regulation of a hydropower plant, including:

[0107] The frequency regulation module is used to read the primary frequency regulation configuration parameters of the hydropower plant units and determine whether a primary frequency regulation event occurs in the hydropower units.

[0108] The data monitoring module collects and monitors the frequency data and active output data of the hydropower plant units in real time through the wide-area measurement system, determines whether the hydropower plant units meet the primary frequency regulation capture conditions, and confirms the grid-connected status of the hydropower plant units.

[0109] Performance calculation module, performance evaluation indicators of the computer group after the hydropower plant units are connected to the grid.

[0110] Embodiment 3, an embodiment of the present invention, is different from the first two embodiments in that:

[0111] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program codes.

[0112] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0113] More specific examples (a non-exhaustive list) of computer-readable media include the following: an electrical connection having one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and editable read-only memory,

[0114] (EPROM or flash memory), fiber optic devices, and portable CD-ROM

[0115] (CDROM). In addition, the computer readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting or processing in another suitable manner as necessary, and then stored in a computer memory.

[0116] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0117] In Example 4, three units of a hydropower plant were selected for the experiment, representing different types of unit configurations and performance levels. The experiment collected the frequency data and active output data of the hydropower plant units in real time through the wide area measurement system (WAMS), and judged whether the unit had a primary frequency modulation event based on the pre-set primary frequency modulation configuration parameters. The main parameters used in the experiment included frequency modulation dead zone, frequency deviation, duration, frequency amplitude, etc., while considering the grid-connected status and stability of the unit.

[0118] The frequency regulation dead zone of each unit is set to ±0.033Hz.

[0119] The minimum duration of the frequency deviation is set to 15 seconds and the maximum duration is set to 60 seconds.

[0120] The steady-state time before frequency modulation is set to 5 seconds, and the frequency modulation response time is set to 30 seconds.

[0121] Active output greater than 5MW is the standard for unit connection to the grid.

[0122] WAMS is used to collect frequency data, frequency deviation, frequency change rate and other information of hydropower plant units in real time. The collected data can be used to determine whether the set frequency regulation capture conditions are met, such as whether the frequency deviation exceeds the frequency regulation dead zone, whether the duration meets the requirements, etc.

[0123] When the frequency regulation capture conditions are met, further confirm whether the unit participates in the frequency regulation operation (through the frequency regulation control signal). Then the performance evaluation indicators of the computer group are calculated, including actual and theoretical integrated power, power contribution rate, monthly operation rate, etc.

[0124] In order to verify the advantages of the present invention, two different sets of data are selected: one set uses the traditional frequency modulation event detection method (based on fixed threshold and offline calculation); the other set uses the detection method based on WAMS real-time monitoring and dynamic calculation proposed by the present invention. The experimental data are shown in Table 1.

[0125] Table 1 Experimental data table

[0126]

[0127] It can be seen from the data in the table that the real-time monitoring and dynamic calculation method of the present invention significantly improves the actual integrated power and power contribution rate of the unit compared with the traditional offline calculation method. For example, the power contribution rate of unit A increased from 91.67% of the traditional method to 104.35%, and the contribution rates of units B and C also increased significantly, reaching 103.45% and 104.00%, respectively. These data show that the present invention can more accurately calculate the frequency modulation capability of the computer group through real-time collection and monitoring, reducing the errors caused by data lag and calculation delay.

[0128] In addition, when the traditional method handles a frequency modulation event, the duration is relatively rough, and most of the calculations are based on offline data, resulting in inaccurate evaluation of the frequency modulation power. For example, in the traditional method, the actual integrated power of unit A is 110kWh, while after calculation by the present invention, it is 120kWh, showing a significant gain. This result shows that the present invention is more accurate in ensuring the determination of the unit's grid-connected status, the duration of frequency deviation, etc., and avoids misjudgment caused by improper parameter settings in the traditional method.

[0129] Further analysis of the improvement in the power contribution rate can be attributed to the dynamic adjustment of the capture conditions of frequency disturbance events by the method of the present invention. By real-time monitoring of factors such as frequency deviation, disturbance amplitude, and grid connection status, the units participating in frequency regulation can be identified and captured in time, while traditional methods mostly rely on fixed thresholds, resulting in some frequency regulation events not being captured in time.

[0130] Algorithm effect comparison results and applications

[0131] In this experiment, by comparing the traditional method and the algorithm effect of the present invention, the advantages of the present invention in frequency modulation event identification and performance evaluation index calculation were verified. Specifically, the present invention can dynamically adjust parameters and flexibly determine the frequency modulation capture conditions based on the real-time data of the hydropower plant units, which significantly improves the frequency modulation response time and accuracy. Traditional methods often have a certain lag when dealing with rapid changes in frequency disturbances, while the present invention can identify frequency modulation events in the shortest time and accurately evaluate the performance of the unit through real-time collection and dynamic calculation.

[0132] From the application perspective, the implementation of the present invention can not only provide real-time frequency regulation capability assessment for hydropower plants, but also optimize the grid dispatching strategy and improve the stability of the entire grid. In large-scale grids and complex dispatching systems, the algorithm of the present invention will greatly improve the frequency regulation efficiency and provide important support for the automation and intelligence of power systems.

[0133] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for online detection of primary frequency modulation in a hydropower plant, characterized in that: include: Read the primary frequency regulation configuration parameters of the hydropower plant units to determine whether a primary frequency regulation event occurs in the hydropower units; The wide-area measurement system collects and monitors the frequency data and active output data of the hydropower plant units in real time, determines whether the hydropower plant units meet the primary frequency regulation capture conditions, and confirms the grid-connected status of the hydropower plant units; Performance evaluation indicators of computer groups based on the grid-connected status of hydropower plant units.

2. The method for online detection of primary frequency modulation in a hydropower plant according to claim 1, characterized in that: The primary frequency regulation configuration parameters include frequency regulation dead zone, minimum duration, maximum duration, effective disturbance amplitude, steady-state time before frequency regulation, frequency regulation response time, unit grid-connected power threshold, frequency capture conditions, frequency regulation exit criteria and frequency regulation performance evaluation criteria; Determining whether a frequency regulation event occurs in a hydropower unit includes determining whether the frequency of the power grid where the hydropower unit is located exceeds the frequency regulation dead zone, and whether the deviation duration exceeds the minimum duration requirement of the frequency regulation event; Determine whether the interval between the current frequency modulation event and the previous frequency modulation event meets the effective disturbance interval.

3. The method for online detection of primary frequency modulation in a hydropower plant according to claim 2, characterized in that: The frequency data of the hydropower plant units include real-time frequency, frequency deviation, frequency change rate and frequency disturbance events; The active output data of the hydropower plant units include the active output of the units, the output variation of the units, the steady combustion load of the units, the maximum adjustable active output of the units and the minimum adjustable active output of the units; The determination of whether the hydropower plant unit meets the primary frequency regulation capture condition includes, when a hydropower unit has a primary frequency regulation event, performing frequency deviation determination, duration determination, frequency amplitude determination, grid connection state determination, pre-frequency regulation steady state determination, frequency regulation state determination, and disturbance interval determination; The frequency deviation judgment includes judging whether the frequency of the power grid where the hydropower unit is located exceeds the primary frequency regulation dead zone; The duration determination includes determining whether the frequency deviation continues for more than a set time; The frequency amplitude determination includes checking whether the disturbance amplitude exceeds a preset effective disturbance threshold frequency disturbance amplitude; The grid-connected status judgment includes judging whether the active output of the unit exceeds the grid-connected power threshold; The steady-state judgment before frequency modulation includes confirming whether the frequency is stable to avoid misjudgment; The frequency modulation state judgment includes checking the frequency modulation input / output signal of the unit to judge whether the unit is in the frequency modulation participation state; The disturbance interval determination includes ensuring whether the intervals between multiple frequency modulation events conform to the effective disturbance interval.

4. The method for online detection of primary frequency modulation in a hydropower plant as claimed in claim 3, characterized in that: Confirming the grid-connected status of the hydropower plant units includes active output inspection, grid-connected and off-grid status determination of the units, stable combustion load determination, frequency regulation status determination, unit control signal determination and unit historical status inspection; The active output check includes checking whether the active output of the hydropower plant unit is greater than the set grid-connected power threshold, and determining whether the time when the active output is less than the grid-connected power threshold continues to exceed the set time; The determination of the grid-connected and off-grid status of the unit includes: when the active output of the unit exceeds the grid-connected power threshold and the duration meets the requirements, the unit is determined to be in the grid-connected state and can participate in the primary frequency regulation; When the active output of the unit is lower than the grid-connected power threshold and the duration exceeds the set value, the unit is judged to be off-grid and cannot participate in frequency regulation; The stable combustion load judgment includes whether the unit is maintained within the stable load range to ensure that the unit will not be disconnected from the grid due to too low load; The frequency modulation state judgment includes confirming whether the unit participates in the frequency modulation operation; The unit control signal includes confirming whether the hydropower plant unit has received a frequency modulation control signal. When the unit has not received a frequency modulation signal or the frequency modulation signal is 0, it is determined that the unit is not involved in the frequency modulation; The unit historical status check includes confirming whether the unit is normal based on the unit historical data and control records.

5. The method for online detection of primary frequency modulation in a hydropower plant as claimed in claim 4, characterized in that: The performance evaluation indicators of the unit include actual integrated power. When the system frequency deviation exceeds the specified range, the statistical program automatically starts, and the average output of the unit two seconds before the dead zone point of the frequency regulation is calculated. o As the base point, integrate the power generation change backward until the system frequency returns to within the unit action dead zone. The formula is expressed as: Among them, P t represents the actual power at time t; t o represents the time when the system frequency exceeds the dead zone of the primary frequency regulation of unit i, t represents the time when the system frequency enters the dead zone of the primary frequency regulation of unit i, P o It indicates the average output of the unit two seconds before the dead zone point of the primary frequency regulation.

6. The method for online detection of primary frequency modulation in a hydropower plant as claimed in claim 5, characterized in that: The performance evaluation index of the unit also includes the theoretical integral power, the theoretical primary frequency regulation integral power H of unit i e The formula is expressed as: Where Δf(t) represents the frequency difference corresponding to the grid frequency change exceeding the dead zone, MCR represents the rated active output of the unit, and f n Indicates the system rated frequency, K c Indicates the speed change rate of the corresponding unit.

7. The method for online detection of primary frequency modulation in a hydropower plant according to claim 6, characterized in that: The performance evaluation indicators of the unit also include power contribution rate, monthly commissioning rate of primary frequency regulation, frequency regulation qualification judgment and stabilization time; The power contribution ratio is actual power contribution / theoretical power contribution; The monthly commissioning rate of primary frequency regulation is monthly commissioning time / grid connection time; Among them, the grid-connected time refers to the operating time when the active power of the unit is greater than the set threshold; the monthly input time refers to the operating time when the unit is judged to be grid-connected and its primary frequency regulation input and output state is input; The frequency modulation qualification judgment includes: when the value of the primary frequency modulation power contribution rate is greater than the set qualified threshold, the frequency modulation is qualified; when the value of the primary frequency modulation power contribution rate is less than the set qualified threshold, the primary frequency modulation is unqualified; The stabilization time includes the time from the start of the unit's active extreme value time to the end of frequency modulation, during which the active power reaches a stable state.

8. An online detection system for primary frequency modulation in a hydropower plant, characterized by: The frequency modulation module is used to read the primary frequency modulation configuration parameters of the hydropower plant units and determine whether a primary frequency modulation event occurs in the hydropower units; The data monitoring module collects and monitors the frequency data and active output data of the hydropower plant units in real time through the wide-area measurement system, determines whether the hydropower plant units meet the primary frequency regulation capture conditions, and confirms the grid-connected status of the hydropower plant units; Performance calculation module, performance evaluation indicators of the computer group after the hydropower plant units are connected to the grid.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the on-line detection method for primary frequency regulation of a hydropower plant described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the on-line detection method for primary frequency regulation of a hydropower plant described in any one of claims 1 to 7 are implemented.

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