Unit inertia online monitoring method, system, device and storage medium

Abstract

The application belongs to the field of power system automation, and discloses a kind of unit inertia on-line monitoring method, system, equipment and storage medium, comprising: obtaining the active power before disturbance of unit current disturbance event and the active power and frequency rate of change of each measuring point time in disturbance calculation interval;Obtain the difference between the active power of each measuring point time and the active power before disturbance, obtain the active power difference of each measuring point time, and obtain the inertia calculation value of each measuring point time in combination with the frequency rate of change of each measuring point time;According to the inertia calculation value of each measuring point time, the inertia calculation value of current disturbance event is obtained, and the active power change value of current disturbance event is obtained according to the active power difference of each measuring point time;Obtain the active power change value and inertia calculation value of several disturbance events of unit, and according to the active power change value of several disturbance events of unit, the inertia calculation value of several disturbance events of unit is weighted and averaged, and the inertia on-line monitoring value of unit is obtained. It can provide on-line monitoring and evaluation means for the real value of each in-service unit inertia, which is not only beneficial to the accurate master of the real inertia level of power grid for power grid dispatching master station, but also can provide strong support for the safe operation of power grid, and promote the further consumption of new energy.

Description

Technical Field

[0001] This invention belongs to the field of power system automation and relates to a method, system, equipment and storage medium for online monitoring of generator unit inertia. Background Technology

[0002] The development and construction of new power systems has driven the energy transformation dominated by "new energy," resulting in a power system characterized by "two highs" (high proportion of new energy and high proportion of power electronic equipment) and "two lows" (low rotational inertia and low short-circuit ratio). Rotational inertia is a crucial guarantee for grid frequency resistance to disturbances and an important aspect of understanding the characteristics of new power systems. However, with the replacement of a large number of conventional generating units, the rotational inertia of synchronous AC grids continues to decrease, reducing the dynamic regulation capability of the power system and weakening its ability to withstand active power surges, frequency fluctuations, and disturbances, making it prone to serious grid failures. The gradual decrease in grid inertia affects grid frequency stability; after disturbances such as unit tripping, it can cause significant frequency drops and trigger cascading failures such as low-frequency load shedding, severely impacting grid operational safety and potentially leading to large-scale blackouts. Therefore, accurately obtaining the inertia values ​​of traditional thermal and hydropower synchronous generating units is particularly necessary while developing and constructing new energy sources on a large scale.

[0003] Currently, the rotational inertia of the power grid is mainly concentrated in traditional synchronous turbine units, especially thermal and hydropower plants. The rotational inertia of each unit is often statistically analyzed using the rated parameters specified by the manufacturers. However, with long-term operation, these parameters often change, and there is a lack of effective means to assess the accuracy of the manufacturer-reported rated parameters after years of operation. Furthermore, some regions are gradually upgrading existing units as power plants undergo upgrades. These upgraded units differ from their predecessors, and relying solely on the original rotational inertia parameters is no longer sufficient. Accurately assessing the rotational inertia of these upgraded units is also lacking effective methods within the industry. Therefore, there is an urgent need for relevant measurement methods to accurately monitor and assess the rotational inertia of units, providing new technical means to accurately grasp the actual rotational inertia of each operating unit, and thus providing strong support for the safe and stable operation of the power grid. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method, system, device and storage medium for online monitoring of unit inertia.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] In a first aspect, the present invention provides a method for online monitoring of generator unit inertia, comprising: acquiring the active power before the disturbance of a current disturbance event, and the active power and frequency change rate at each measuring point within the disturbance calculation interval; acquiring the difference between the active power at each measuring point and the active power before the disturbance, obtaining the active power difference at each measuring point, and combining it with the frequency change rate at each measuring point to obtain the inertia calculation value at each measuring point; obtaining the inertia calculation value of the current disturbance event based on the inertia calculation value at each measuring point, and obtaining the active power change value of the current disturbance event based on the active power difference at each measuring point; acquiring the active power change value and inertia calculation value of a potential disturbance event, and weighting the inertia calculation value of the potential disturbance event based on the active power change value of the potential disturbance event to obtain the online monitoring value of the generator unit inertia.

[0007] Optionally, the active power before the disturbance is the average active power at each measuring point within a preset time period before the current disturbance event occurs; the disturbance calculation interval is T0+T. e ~T0+T d Where T0 is the time of occurrence of the current disturbance event for the unit, and T... e For the first preset time period, T d This is the second preset time period.

[0008] Optionally, the step of obtaining the inertia calculation value at each measuring point by combining the frequency change rate at each measuring point includes: dividing the active power difference at each measuring point by the frequency change rate at each measuring point to obtain the inertia calculation value at each measuring point.

[0009] Optionally, obtaining the inertia calculation value of the current disturbance event based on the inertia calculation value at each measuring point time, and obtaining the active power change value of the current disturbance event based on the active power difference at each measuring point time, includes: smoothing the inertia calculation value at each measuring point time to obtain smoothed inertia calculation values ​​at several measuring points time, averaging the smoothed inertia calculation values ​​at several measuring points time to obtain the inertia calculation value of the current disturbance event; and averaging the active power difference at the measuring points time corresponding to the smoothed inertia calculation values ​​to obtain the active power change value of the current disturbance event.

[0010] Optionally, the smoothing process for the inertia calculation values ​​at each measurement point includes: extracting a processing time window within the disturbance calculation interval, setting the inertia calculation values ​​at each measurement point outside the processing time window, and obtaining the median of the inertia calculation values ​​at each measurement point within the processing time window to obtain the median inertia calculation value; obtaining the deviation between the inertia calculation values ​​at each measurement point within the processing time window and the median inertia calculation value, and obtaining the median of the deviation values ​​to obtain the median deviation value; removing the inertia calculation values ​​at the measurement point corresponding to the deviation values ​​that are greater than a preset multiple of the median deviation value; and smoothing the remaining inertia calculation values ​​at each measurement point using the moving average method based on the moving time window.

[0011] Optionally, obtaining the active power change value and inertia calculation value of the unit under a disturbance event, and weighting the inertia calculation value of the unit under a disturbance event based on the active power change value of the unit under a disturbance event, includes: weighting the inertia calculation value of the unit under a disturbance event using the following formula:

[0012]

[0013] Where, ΔP i H represents the change in active power for the target disturbance event i. i H is the calculated inertia value of the target disturbance event i; H is the online monitoring value of the unit's inertia; the target disturbance event is a disturbance event in which the change in active power is greater than the threshold value of the change in active power; and n is the number of target disturbance events.

[0014] In a second aspect, the present invention provides an online monitoring system for generator unit inertia, comprising: a data acquisition module for acquiring the active power before the disturbance of a current disturbance event, and the active power and frequency change rate at each measuring point within the disturbance calculation interval; a measuring point time calculation module for acquiring the difference between the active power at each measuring point and the active power before the disturbance, obtaining the active power difference at each measuring point, and combining it with the frequency change rate at each measuring point to obtain the inertia calculation value at each measuring point; a disturbance event calculation module for obtaining the inertia calculation value of the current disturbance event based on the inertia calculation value at each measuring point, and obtaining the active power change value of the current disturbance event based on the active power difference at each measuring point; and an inertia monitoring module for acquiring the active power change value and the inertia calculation value of a potential disturbance event, and for weighted averaging the inertia calculation value of the potential disturbance event based on the active power change value of the potential disturbance event to obtain the online monitoring value of the generator unit inertia.

[0015] Optionally, the inertia monitoring module is specifically used to: perform a weighted average of the inertia calculation values ​​of several disturbance events of the unit using the following formula:

[0016]

[0017] Where, ΔP i H represents the change in active power for the target disturbance event i. i H is the calculated inertia value of the target disturbance event i; H is the online monitoring value of the unit's inertia; the target disturbance event is a disturbance event in which the change in active power is greater than the threshold value of the change in active power; and n is the number of target disturbance events.

[0018] In a second aspect, the present invention provides a computer device including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the above-described online monitoring method for unit inertia.

[0019] In a third aspect, the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the above-described online monitoring method for unit inertia.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] This invention provides an online monitoring method for generator unit inertia. Based on generator unit disturbance events, it obtains the calculated inertia value and active power change value of the disturbance event by using the active power before the disturbance and the active power and frequency change rate at each measuring point within the disturbance calculation interval. Then, based on the active power change value and inertia calculation value of the generator unit under a disturbance event, and by weighting the inertia calculation value of the disturbance event according to the active power change value, it obtains the online monitoring value of the generator unit's inertia. By continuously calculating the inertia value at each measuring point after the disturbance event occurs and by weighting the calculation results of multiple disturbance events, it can provide an online monitoring and evaluation method for the true inertia value of each operating generator unit. This not only helps the power grid dispatching station accurately grasp the true inertia level of the power grid, but also provides strong support for the safe operation of the power grid, and promotes the further consumption of new energy sources while ensuring the safe and stable operation of the power grid. Attached Figure Description

[0022] Figure 1 This is a flowchart of the unit inertia online monitoring method according to an embodiment of the present invention.

[0023] Figure 2 This is a schematic diagram of the disturbance calculation interval in an embodiment of the present invention.

[0024] Figure 3 This is a schematic diagram illustrating the smoothing process of inertia calculation values ​​according to an embodiment of the present invention.

[0025] Figure 4 This is a schematic diagram illustrating the statistical analysis of the calculated inertia values ​​of multiple disturbance events in an embodiment of the present invention.

[0026] Figure 5 This is a structural block diagram of the unit inertia online monitoring system according to an embodiment of the present invention. Detailed Implementation

[0027] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0028] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0029] The present invention will now be described in further detail with reference to the accompanying drawings:

[0030] See Figure 1 In one embodiment of the present invention, a method for online monitoring of unit inertia is provided, specifically a method for online monitoring of unit inertia based on plant measurement data, which can provide online monitoring and evaluation means for the true value of the inertia of each operating unit, and provide support for the safe operation of the power grid.

[0031] Specifically, the online monitoring method for unit inertia of the present invention includes the following steps:

[0032] S1: Obtain the active power before the disturbance of the current disturbance event of the unit, as well as the active power and frequency change rate at each measuring point within the disturbance calculation interval.

[0033] S2: Obtain the difference between the active power at each measuring point and the active power before the disturbance, obtain the active power difference at each measuring point, and combine it with the frequency change rate at each measuring point to obtain the inertia calculation value at each measuring point.

[0034] S3: Calculate the inertia value of the current disturbance event based on the inertia calculation value at each measuring point, and calculate the active power change value of the current disturbance event based on the active power difference at each measuring point.

[0035] S4: Obtain the active power change value and inertia calculation value of the unit under the disturbance event, and perform a weighted average of the inertia calculation value of the unit under the disturbance event based on the active power change value of the unit under the disturbance event to obtain the unit's online inertia monitoring value.

[0036] This invention provides an online monitoring method for generator unit inertia. Based on generator unit disturbance events, it obtains the calculated inertia value and active power change value of the disturbance event by using the active power before the disturbance and the active power and frequency change rate at each measuring point within the disturbance calculation interval. Then, based on the active power change value and inertia calculation value of the generator unit under a disturbance event, and by weighting the inertia calculation value of the disturbance event according to the active power change value, it obtains the online monitoring value of the generator unit's inertia. By continuously calculating the inertia value at each measuring point after the disturbance event occurs and by weighting the calculation results of multiple disturbance events, it can provide an online monitoring and evaluation method for the true inertia value of each operating generator unit. This not only helps the power grid dispatching station accurately grasp the true inertia level of the power grid, but also provides strong support for the safe operation of the power grid, and promotes the further consumption of new energy sources while ensuring the safe and stable operation of the power grid.

[0037] In one possible implementation, the active power before the disturbance of the current disturbance event of the unit, as well as the active power and frequency change rate at each measuring point within the disturbance calculation interval, can be obtained by receiving measurement data from the PMU (Phasor Measurement Unit) of each plant.

[0038] Currently, power plants using synchronous generators, including thermal, hydro, and nuclear power plants, have deployed PMU (Power Measurement Unit) devices. These PMU devices transmit real-time measurement data to the WAMS (Wide Area Measurement System) master station in the dispatch center for comprehensive monitoring and display. The data transmitted in real-time by the PMU devices mainly includes three-phase fundamental voltage, three-phase fundamental current, positive sequence voltage, positive sequence current, frequency, rate of frequency change, active power, reactive power, and switching signal information.

[0039] When the power grid experiences disturbances, including generator tripping, sudden increases or decreases in load, the grid frequency fluctuates, and its rate of change also changes. If the rate of change exceeds a limit, the PMU (Power Management Unit) will trigger an alarm. At this time, the dispatch master station can receive the alarm information sent by the substations and the exact time of the alarm. In addition, the dispatch master station can also make its own judgments based on the data sent by the PMUs of each substation, especially regarding changes in frequency and the rate of change.

[0040] Currently, the maximum data transmission rate from the PMU device to the WAMS master station in the dispatch center is 100 frames per second, meaning that measurement data is transmitted once every 10 ms, resulting in 100 measurement data points per second. Because this transmission rate generates a large number of data points, it puts pressure on the subsequent storage of the dispatch master station. Therefore, many dispatch master stations often use a transmission rate of 50 frames per second for data transmission. In this way, the dispatch master station can receive 50 measurement data points per second, with each measurement data point spaced 20 ms apart.

[0041] When a disturbance causes a significant change in the frequency change rate that exceeds the alarm threshold of the PMU (Power Management Unit), the PMU will continue to transmit measurement data in real time and simultaneously transmit alarm information to the dispatch master station. Upon receiving the frequency change rate exceeding the limit alarm information, the master station can determine the moment the disturbance occurred based on the alarm information. This moment is not the actual time the disturbance occurred, but it is the moment the device determines as the start time and can be used as the starting point for subsequent calculations.

[0042] Furthermore, in actual engineering operations, such significant disturbances are relatively infrequent; more common are smaller disturbances. These disturbances do not trigger alarms such as excessive frequency change rate or low frequency in the PMU device. Therefore, in such cases, the dispatch master station can perform the disturbance calculation itself. In specific implementation, the dispatch master station can flexibly set a threshold for judgment to facilitate flexible calculation. This can be based on the frequency change rate or the active power change value; in short, these threshold settings can be flexibly adjusted by the master station.

[0043] In one possible implementation, the active power before the disturbance is the average active power at each measuring point within a preset time period before the current disturbance event occurs.

[0044] Specifically, regarding the determination of active power before the disturbance, the starting point is T0, when the dispatch master station determines the current disturbance event, and then the time T is selected backwards. b The active power before the disturbance is calculated based on the active power over the time range. This is specifically the time frame T0-T. b The average active power at all measuring points from time T0 to time T1 is used to obtain the calculation benchmark for the change in active power during the current disturbance event, i.e., the active power before the disturbance. Where T1...b The time can be flexibly set according to the project, such as 0.5s or 1s.

[0045] In one possible implementation, the disturbance calculation interval is T0+T e ~T0+T d Where T0 is the time of occurrence of the current disturbance event for the unit, and T... e For the first preset time period, T d This is the second preset time period.

[0046] For details, see Figure 2 When a power plant or dispatching master station triggers a frequency change rate exceeding the limit alarm, the alarm time is used to determine the start time of the disturbance. Since the data used by the PMU device within its measurement window immediately after the disturbance occurs includes data from both before and after the disturbance, the measured data not only has a large deviation, but the power grid itself also experiences significant fluctuations. Therefore, this invention sets a calculated window period T to avoid the period immediately following the disturbance. e That is, when the system starts from the time T0 when the disturbance occurs, it waits for T0+T. e The inertia calculation will begin after time T. e It can be flexibly set according to needs, such as setting it to 100ms.

[0047] Since the master station can perform a calculation and obtain the calculated inertia value for each PMU device's transmitted data, continuous monitoring will continue until a frequency modulation initiation occurs. For large disturbances, the system will initiate a frequency modulation if the frequency drop is too large after an alarm indicating that the rate of frequency change has exceeded the limit. However, for small disturbances, frequency modulation will not be initiated in most cases. Therefore, continuous inertia monitoring requires a time period and is not performed indefinitely. Thus, a continuous calculation time period T can be set. d Considering that a single frequency modulation operation can affect the online inertia monitoring results, the inertia calculation needs to avoid the initiation of the single frequency modulation. However, a single frequency modulation often starts within 1–3 seconds after a disturbance occurs; therefore, the continuous inertia calculation time T is limited. d It is generally recommended not to exceed 3 seconds.

[0048] In one possible implementation, the step of obtaining the inertia calculation value at each measuring point by combining the frequency change rate at each measuring point includes: dividing the active power difference at each measuring point by the frequency change rate at each measuring point to obtain the inertia calculation value at each measuring point.

[0049] Specifically, after the calculation is initiated, from that moment onward, each data transmission from the PMU device will include the frequency change rate and the latest active power. The received active power is subtracted from the active power before the disturbance to obtain the active power difference. The inertia calculation value is then calculated using the obtained active power difference and the frequency change rate. That is, the active power difference at each measurement point is divided by the frequency change rate at each measurement point to obtain the inertia calculation value at each measurement point. This calculation is performed for each frame of data transmitted by the PMU device until T0+T. d time.

[0050] In one possible implementation, obtaining the inertia calculation value of the current disturbance event based on the inertia calculation values ​​at each measuring point time, and obtaining the active power change value of the current disturbance event based on the active power difference at each measuring point time, includes: smoothing the inertia calculation values ​​at each measuring point time to obtain smoothed inertia calculation values ​​at several measuring point times, averaging the smoothed inertia calculation values ​​at several measuring point times to obtain the inertia calculation value of the current disturbance event; and averaging the active power difference values ​​at the measuring point times corresponding to the several smoothed inertia calculation values ​​to obtain the active power change value of the current disturbance event.

[0051] The inertia calculation values ​​at each measurement point are smoothed to eliminate abnormal data caused by various possible reasons and reduce the data fluctuation of the inertia calculation values ​​at each measurement point, so as to improve the accuracy of the final result.

[0052] Optionally, the smoothing process for the inertia calculation values ​​at each measurement point includes: extracting a processing time window within the disturbance calculation interval, setting the inertia calculation values ​​at each measurement point outside the processing time window, and obtaining the median of the inertia calculation values ​​at each measurement point within the processing time window to obtain the median inertia calculation value; obtaining the deviation between the inertia calculation values ​​at each measurement point within the processing time window and the median inertia calculation value, and obtaining the median of the deviation values ​​to obtain the median deviation value; removing the inertia calculation values ​​at the measurement point corresponding to the deviation values ​​that are greater than a preset multiple of the median deviation value; and smoothing the remaining inertia calculation values ​​at each measurement point using the moving average method based on the moving time window.

[0053] See you again Figure 2 For the inertia results calculated continuously after the disturbance occurs, a processing time window is selected from the start of the calculation for processing. The specific processing time window T w It can be flexibly configured, for example, to 500ms, so that all inertia monitoring data will be from T0+T e +T w The subsequent value. For example, if T0 = 0, T e =100ms, T w= 500ms, so the selected data is the data between 100ms and 600ms after the disturbance occurs. Assuming a data rate of 50 frames / second (the PMU data transmission interval is 20ms), this 500ms data window will have 25 inertia calculation values, which will then be processed.

[0054] Of course, the selected processing time window does not have to be from T0+T. e To begin, for example, from T0+T e Within the time range up to T0+1s, according to T w Considering a 500ms timeframe, you could choose data from 200ms to 700ms, or data from 250ms to 750ms, etc. In short, regardless of the choice, the data is extracted from the continuous inertia calculation time series for a processing window; the remaining data is left unprocessed.

[0055] First, see Figure 3 The moving median method is used to sort the inertia calculation values ​​within the processing time window and find the median, i.e., the median inertia calculation value. Then, the deviation between each inertia calculation value and the median inertia calculation value is calculated. These deviations are then sorted again to find the median of the deviations, i.e., the median deviation value. If there is a deviation value that is more than 3 times the median deviation value, the corresponding inertia calculation value is directly removed, thereby removing abnormal maxima or abnormal minima in the inertia calculation values.

[0056] In addition, if the inertia calculation value is to be displayed as a curve, considering that removing outliers will affect the continuity of the data, three times the median deviation value can be used as the set deviation to supplement the removed inertia calculation value.

[0057] Next, the remaining inertia calculation values ​​are smoothed using the moving average method. A moving time window is set, which can be flexibly set, such as 3 or 5, to smooth the remaining inertia calculation data. This method can further filter out relevant fluctuations in the data and obtain smoother inertia calculation monitoring results. Finally, smoothed inertia calculation values ​​at several measurement points are obtained.

[0058] Although the inertia calculation for this disturbance event is complete after the above steps, it is necessary to additionally calculate the final inertia and active power change values ​​for this disturbance event in order to perform statistical analysis on the inertia calculation values ​​of numerous disturbance events. The specific statistical method involves obtaining the inertia calculation value for the current disturbance event based on the smoothed inertia calculation values ​​at several measurement points. This is achieved by averaging the smoothed inertia calculation values ​​at several measurement points to obtain the inertia calculation value for the current disturbance event. Similarly, it involves obtaining the active power change value for the current disturbance event by averaging the active power difference at the measurement points corresponding to the smoothed inertia calculation values. In other words, when averaging the active power difference, only the active power difference data at the measurement points used to calculate the inertia calculation value for the current disturbance event is used. For example, with the aforementioned 500ms processing data window, and a message frame of 20ms, there would be 50 data points. If one abnormal maximum and one abnormal minimum are removed, then 48 data points remain. The power difference at the corresponding measurement point time is statistically summed and the average is calculated.

[0059] In one possible implementation, obtaining the active power change value and inertia calculation value of the unit under a disturbance event, and then weighting the inertia calculation value of the unit under a disturbance event based on the active power change value of the unit under a disturbance event, includes: weighting the inertia calculation value of the unit under a disturbance event using the following formula:

[0060]

[0061] Where, ΔP i H represents the change in active power for the target disturbance event i. i H is the calculated inertia value of the target disturbance event i; H is the online monitoring value of the unit's inertia; the target disturbance event is a disturbance event in which the change in active power is greater than the threshold value of the change in active power; and n is the number of target disturbance events.

[0062] Specifically, after each disturbance, the unit generates an inertia calculation value. However, disturbances vary in magnitude, and the accuracy of the inertia calculation value for small disturbances is lower than that for large disturbances. Therefore, the inertia calculation values ​​after each disturbance event may differ to some extent. To more accurately reflect the true value of inertia, a weighted aggregation method can be used for calculation.

[0063] First, see Figure 4The system comprehensively compares the active power changes from various disturbance events. By setting a threshold for active power change, disturbance events with active power changes exceeding this threshold are selected and used as the data basis for weighted calculations. The active power change threshold can be flexibly set according to a certain proportion based on the rated power of the unit, such as 5% or 10% of the rated value.

[0064] This setup is primarily to exclude calculation results under minor disturbances, ensuring the accuracy of inertia monitoring results. Secondly, the inertia calculation values ​​of the filtered disturbance events (i.e., the target disturbance events) are summarized. The inertia calculation value of each disturbance event is multiplied by the active power change value of that disturbance event, summed, and then divided by the total active power change value of these filtered target disturbance events to obtain the final online inertia monitoring value.

[0065] The following are embodiments of the apparatus of the present invention, which can be used to execute embodiments of the method of the present invention. For details not disclosed in the apparatus embodiments, please refer to the embodiments of the method of the present invention.

[0066] See Figure 5 In another embodiment of the present invention, a unit inertia online monitoring system is provided, which can be used to implement the above-mentioned unit inertia online monitoring method. Specifically, the unit inertia online monitoring system includes a data acquisition module, a measurement point time calculation module, a disturbance event calculation module, and an inertia monitoring module.

[0067] The data acquisition module is used to acquire the active power before the disturbance of the current disturbance event of the unit, as well as the active power and frequency change rate at each measuring point within the disturbance calculation interval; the measuring point time calculation module is used to acquire the difference between the active power at each measuring point and the active power before the disturbance, to obtain the active power difference at each measuring point, and to obtain the inertia calculation value at each measuring point by combining it with the frequency change rate at each measuring point; the disturbance event calculation module is used to obtain the inertia calculation value of the current disturbance event based on the inertia calculation value at each measuring point, and to obtain the active power change value of the current disturbance event based on the active power difference at each measuring point; the inertia monitoring module is used to acquire the active power change value and inertia calculation value of the unit under the disturbance event, and to perform a weighted average of the inertia calculation value of the unit under the disturbance event based on the active power change value of the unit under the disturbance event, to obtain the unit's online inertia monitoring value.

[0068] In one possible implementation, the inertia monitoring module is specifically used to: perform a weighted average of the inertia calculation values ​​of several disturbance events of the unit using the following formula:

[0069]

[0070] Where, ΔP iH represents the change in active power for the target disturbance event i. i H is the calculated inertia value of the target disturbance event i; H is the online monitoring value of the unit's inertia; the target disturbance event is a disturbance event in which the change in active power is greater than the threshold value of the change in active power; and n is the number of target disturbance events.

[0071] All relevant content of each step involved in the aforementioned embodiments of the unit inertia online monitoring method can be referenced to the functional description of the corresponding functional module of the unit inertia online monitoring system in the embodiments of the present invention, and will not be repeated here.

[0072] The module division in this embodiment of the invention is illustrative and represents only one logical functional division. In actual implementation, other division methods may be used. Furthermore, the functional modules in the various embodiments of the invention can be integrated into a single processor, exist as separate physical entities, or be integrated into a single module. The integrated modules described above can be implemented in hardware or as software functional modules.

[0073] In another embodiment of the present invention, a computer device is provided, comprising a processor and a memory. The memory stores a computer program, which includes program instructions. The processor executes the program instructions stored in the computer storage medium. The processor may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing and control core of the terminal, suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions from the computer storage medium to achieve a corresponding method flow or function. The processor described in this embodiment of the present invention can be used for the operation of a unit inertia online monitoring method.

[0074] In another embodiment of the present invention, a storage medium is provided, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device used to store programs and data. It is understood that the computer-readable storage medium here can include both the built-in storage medium in the computer device and extended storage media supported by the computer device. The computer-readable storage medium provides storage space that stores the terminal's operating system. Furthermore, the storage space also stores one or more instructions suitable for loading and execution by a processor. These instructions can be one or more computer programs (including program code). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk storage device. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the corresponding steps of the online monitoring method for unit inertia in the above embodiments.

[0075] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0076] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0077] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1The function specified in one or more boxes.

[0078] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for online monitoring of unit inertia, characterized in that, include: Obtain the active power before the disturbance event of the unit, as well as the active power and frequency change rate at each measuring point within the disturbance calculation interval; The difference between the active power at each measuring point and the active power before the disturbance is obtained, and the active power difference at each measuring point is obtained. Combined with the frequency change rate at each measuring point, the inertia value at each measuring point is calculated. The inertia calculation value of the current disturbance event is obtained based on the inertia calculation value at each measuring point, and the active power change value of the current disturbance event is obtained based on the active power difference at each measuring point. The active power change value and inertia calculation value of the unit under the disturbance event are obtained. Based on the active power change value of the unit under the disturbance event, the inertia calculation value of the unit under the disturbance event is weighted and averaged to obtain the inertia online monitoring value of the unit. The process of obtaining the inertia calculation value of the current disturbance event based on the inertia calculation value at each measuring point, and obtaining the active power change value of the current disturbance event based on the active power difference at each measuring point, includes: The inertia calculation values ​​at each measurement point are smoothed to obtain smoothed inertia calculation values ​​at several measurement points. The smoothed inertia calculation values ​​at several measurement points are then averaged to obtain the inertia calculation value for the current disturbance event. The active power change value of the current disturbance event is obtained by averaging the active power differences at the measurement points corresponding to several smoothed inertia calculation values. The smoothing process for the inertia calculation values ​​at each measurement point includes: Within the disturbance calculation interval, a processing time window is extracted. The inertia calculation values ​​at each measurement point outside the processing time window are set, and the median of the inertia calculation values ​​at each measurement point within the processing time window is obtained to obtain the median inertia calculation value. The deviation between the inertia calculation values ​​at each measurement point within the processing time window and the median inertia calculation value is obtained, and the median of each deviation value is obtained to obtain the median deviation value. The inertia calculation values ​​at the measurement point corresponding to the deviation values ​​that are greater than a preset multiple of the median deviation value are removed. The remaining inertia calculation values ​​at each measurement point are smoothed and filtered using the moving average method based on the moving time window. The step of obtaining the active power change value and inertia calculation value of the unit under a disturbance event, and then weighting the inertia calculation value of the unit under a disturbance event based on the active power change value of the unit under a disturbance event, includes: The calculated inertia values ​​of the unit under disturbance events are weighted and averaged using the following formula: in, For target perturbation events The change in active power, For target perturbation events The calculated value of inertia; The value is the unit's online inertia monitoring value; the target disturbance event is a disturbance event where the change in active power exceeds the active power change threshold. The target number of disturbance events.

2. The method for online monitoring of unit inertia according to claim 1, characterized in that, The active power before the disturbance is the average active power at each measuring point within a preset time period before the current disturbance event occurs. The disturbance calculation interval is T0+T e ~T0+T d Where T0 is the time of occurrence of the current disturbance event for the unit, and T... e For the first preset time period, T d This is the second preset time period.

3. The method for online monitoring of unit inertia according to claim 1, characterized in that, The method of obtaining the inertia calculation value at each measuring point by combining the frequency change rate at each measuring point includes: dividing the difference in active power at each measuring point by the frequency change rate at each measuring point to obtain the inertia calculation value at each measuring point.

4. A unit inertia online monitoring system, characterized in that, include: The data acquisition module is used to acquire the active power before the disturbance of the current disturbance event of the unit, as well as the active power and frequency change rate at each measuring point within the disturbance calculation interval. The measurement point time calculation module is used to obtain the difference between the active power at each measurement point time and the active power before the disturbance, obtain the active power difference at each measurement point time, and combine it with the frequency change rate at each measurement point time to obtain the inertia calculation value at each measurement point time. The disturbance event calculation module is used to obtain the inertia calculation value of the current disturbance event based on the inertia calculation value at each measuring point at time, and to obtain the active power change value of the current disturbance event based on the active power difference at each measuring point at time. The inertia monitoring module is used to acquire the active power change value and inertia calculation value of the unit under the influence of disturbance events. Based on the active power change value of the unit under the influence of disturbance events, the inertia calculation value of the unit under the influence of disturbance events is weighted and averaged to obtain the inertia online monitoring value of the unit. The process of obtaining the inertia calculation value of the current disturbance event based on the inertia calculation value at each measuring point, and obtaining the active power change value of the current disturbance event based on the active power difference at each measuring point, includes: The inertia calculation values ​​at each measurement point are smoothed to obtain smoothed inertia calculation values ​​at several measurement points. The smoothed inertia calculation values ​​at several measurement points are then averaged to obtain the inertia calculation value for the current disturbance event. The active power change value of the current disturbance event is obtained by averaging the active power differences at the measurement points corresponding to several smoothed inertia calculation values. The smoothing process for the inertia calculation values ​​at each measurement point includes: Within the disturbance calculation interval, a processing time window is extracted. The inertia calculation values ​​at each measurement point outside the processing time window are set, and the median of the inertia calculation values ​​at each measurement point within the processing time window is obtained to obtain the median inertia calculation value. The deviation between the inertia calculation values ​​at each measurement point within the processing time window and the median inertia calculation value is obtained, and the median of each deviation value is obtained to obtain the median deviation value. The inertia calculation values ​​at the measurement point corresponding to the deviation values ​​that are greater than a preset multiple of the median deviation value are removed. The remaining inertia calculation values ​​at each measurement point are smoothed and filtered using the moving average method based on the moving time window. The step of obtaining the active power change value and inertia calculation value of the unit under a disturbance event, and then weighting the inertia calculation value of the unit under a disturbance event based on the active power change value of the unit under a disturbance event, includes: The calculated inertia values ​​of the unit under disturbance events are weighted and averaged using the following formula: in, For target perturbation events The change in active power, For target perturbation events The calculated value of inertia; The value is the unit's online inertia monitoring value; the target disturbance event is a disturbance event where the change in active power exceeds the active power change threshold. The target number of disturbance events.

5. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the unit inertia online monitoring method as described in any one of claims 1 to 3.

6. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the unit inertia online monitoring method as described in any one of claims 1 to 3.

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