Power system monitoring device, power system operation monitoring method, and program

Abstract

To provide a power system monitoring device capable of increasing the transmission capacity of a power system while ensuring the reliability of a power transmission / distribution facility.SOLUTION: A power system monitoring device according to an embodiment includes: an air situation estimation unit that, based on a result obtained by subjecting weather data concerning the weather in an evaluation target area including a power transmission / distribution facility of a power system to an air-flow analysis, estimates an air situation of the power transmission / distribution facility; and a tidal value calculation unit that, in accordance with an estimation result of the air situation of the power transmission / distribution facility, calculates, as a tidal value of the power transmission / distribution facility, a maximum tidal value which is more than or equal to a preset rated value.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] An embodiment of the present invention relates to a power system monitoring device, a power system operation monitoring method, and a program. [Background technology]

[0002] Due to the recent liberalization of the electric power industry, it has become common for electricity generated by renewable energy power generation equipment such as wind power generation equipment and solar power generation equipment to be transmitted and distributed via existing power transmission and distribution facilities. In addition to promoting the effective use of renewable energy power generation equipment, there has been active discussion about how to make effective use of existing power transmission and distribution facilities.

[0003] Among these, the application of dynamic rating, which determines the maximum current amount taking into account weather conditions (temperature, wind, sunshine), is expected. Dynamic rating is a technology that increases the transmission capacity of the power system by changing the predetermined power flow value of the power transmission and distribution equipment to a value that keeps the equipment below its upper limit temperature. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2020 / 090021 Summary of the Invention [Problem to be solved by the invention]

[0005] In dynamic rating, the current capacity of a transmission line, a type of power transmission and distribution equipment, is dynamically set taking into account weather conditions. This current capacity is limited by the thermal capacity of the transmission line. This thermal capacity varies depending on Joule heat, heat absorption from sunlight, convective losses due to wind, and radiation losses caused by temperature differences with the outside air temperature. Wind conditions have a significant impact on convective cooling and radiation cooling. Therefore, if wind conditions are not predicted accurately, a situation may occur in which, for example, current flows through a transmission line exceeding the upper limit of the thermal capacity. This could reduce the reliability of the power transmission and distribution equipment.

[0006] The problem to be solved by the present invention is to provide a power system monitoring device, a power system operation monitoring method, and a program that are capable of increasing the transmission capacity of a power system while ensuring the reliability of power transmission and distribution equipment. [Means for solving the problem]

[0007] An electric power system monitoring device according to one embodiment includes a wind condition estimation unit that estimates wind conditions for the electric power transmission and distribution equipment based on the results of airflow analysis of meteorological data relating to the weather in an evaluation area including the electric power system's electric power transmission and distribution equipment, and a power flow value calculation unit that calculates a maximum power flow value for the electric power transmission and distribution equipment that is equal to or greater than a predetermined rated value, based on the estimated wind conditions for the electric power transmission and distribution equipment. [Effects of the Invention]

[0008] According to this embodiment, it is possible to increase the transmission capacity of the power grid while ensuring the reliability of the power transmission and distribution facilities. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a block diagram showing the overall configuration of a power operation system using a power system monitoring device according to a first embodiment. [Figure 2] FIG. 1 is a schematic diagram showing an example of installation of a power transmission line. [Figure 3] 1 is a block diagram showing the configuration of a power system monitoring device according to a first embodiment. [Figure 4]3 is a flowchart showing the procedure of an operation performed by the power system monitoring device according to the first embodiment to monitor a power system. [Figure 5] 10A and 10B are diagrams for explaining details of the wind condition estimation operation. [Figure 6] 10 is a graph showing an example of airflow analysis data for a wide area. [Figure 7] 10 is a diagram showing an example of a display image of the maximum power flow value for each section of the power transmission line and the airflow analysis results of the wind condition estimation unit. FIG. [Figure 8] FIG. 10 is a diagram illustrating an example of margin data. [Figure 9] FIG. 10 is a diagram showing an example of a display of a margin. [Figure 10] 10 is an example of a distribution map of the appearance ratio of wind speed bins. [Figure 11] (a) is an example of a distribution map of the occurrence probability of each wind speed, (b) is an example of a distribution map of the occurrence probability of the angle formed by the wind direction and the conductor of the transmission line, and (c) is an example of a distribution map of the occurrence probability of the allowable current of the transmission line. [Figure 12] FIG. 10 is a schematic diagram for explaining a wind condition estimation step according to the second embodiment. [Figure 13] 10 is a graph showing an example of wind speed trend waveforms at a weather forecast point and a wind speed estimation point. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The present invention is not limited to the following embodiments.

[0011] (First embodiment) Fig. 1 is a block diagram showing the overall configuration of a power operation system using a power system monitoring device according to Embodiment 1. The power operation system shown in Fig. 1 includes a power system monitoring device 1, a power control device 8, and a power system 3.

[0012] First, the power system 3 will be described. The power system 3 is a power supply network that supplies electric power. The power system 3 includes a generator 4, a renewable energy power generation device 5, a transformer 6, and a transmission line 7. As an example, the power system 3 is configured by a plurality of power systems 3a, 3b, 3c, 3d, and 3e. The power system 3 may also include circuit breakers, disconnecting switches, phase modifiers, and the like.

[0013] The power system 3a is composed of a generator 4a, a transformer 6a, and a transmission line 7a. The generator 4a is a facility that generates electricity using hydroelectric power, thermal power, nuclear power, etc. The output power of the generator 4a is controlled by a power control device 8. The transformer 6a transforms the power output from the generator 4a. The transformer 6a has a tap for switching voltage. The transmission line 7a transmits the power transformed by the transformer 6a.

[0014] The power system 3b is made up of a generator 4b, a transformer 6b, and a transmission line 7b. The electric power generated by the generator 4b is transformed by the transformer 6b and transmitted via the transmission line 7b.

[0015] The power system 3c is made up of a renewable energy power generation device 5, a transformer 6c, and a power transmission line 7c. The renewable energy power generation device 5 is a device that generates power using renewable energy such as wind power or solar power. The output power of the renewable energy power generation device 5 is controlled by a power control device 8.

[0016] Power system 3d is composed of transformer 6d and transmission line 7d. Transformer 6d transforms the electric power supplied from power system 3a, power system 3b, and power system 3c. Transmission line 7d transmits the electric power transformed by transformer 6a.

[0017] The power system 3e is composed of a transformer 6e and a transmission line 7e. The electric power supplied from the power system 3a, the power system 3b, and the power system 3c is transformed by the transformer 6e and transmitted via the transmission line 7e.

[0018] The transformers 6a to 6e of the power systems 3a to 3e are provided with measuring devices 61a to 61e, respectively. The measuring devices 61 measure the current temperature, power, voltage, current, and frequency of the transformers 6. The measuring devices 61 are composed of measuring circuits for the temperature, power, voltage, current, and frequency, and transmitting / receiving circuits.

[0019] Measuring devices 71a to 71e are provided on the power transmission lines 7a to 7e of the power systems 3a to 3e, respectively. Measuring device 71 measures the current temperature, power, voltage, current, and frequency on power transmission line 7. Measuring device 71 is composed of measuring circuits for temperature, power, voltage, current, and frequency, and transmitting / receiving circuits.

[0020] Fig. 2 is a schematic diagram showing an example of the installation of a power transmission line 7. As shown in Fig. 2, the power transmission line 7 is installed between a plurality of steel towers 30. In addition, various trees 40 stand in each section D of the power transmission line 7 separated by the steel towers 30.

[0021] Next, the power system monitoring device 1 will be described with reference to Fig. 1. The power system monitoring device 1 is a device that calculates the amount of power generated by a generator 4 or a renewable energy power generation device 5 that keeps the temperature rise of existing power transmission and distribution facilities below a predetermined limit value, without being limited by a defined rated value.

[0022] The power system monitoring device 1 is connected to the power system 3 via a communication line 91, and is also connected to the power control device 8 via a communication line 93. The power system monitoring device 1 is configured with a computer or the like. The power system monitoring device 1 is installed in the office or the like of a business operator that monitors or controls the power system 3.

[0023] 3 is a block diagram showing the configuration of the power system monitoring device 1 according to the first embodiment. The power system monitoring device 1 includes a receiving unit 11, a transmitting unit 12, a computing unit 13, a storage unit 14, and a display unit 15. Each unit will be described below.

[0024] The receiving unit 11 has an online data receiving unit 111 and an offline data receiving unit 112. The online data receiving unit 111 is connected to the measuring devices 61 and 71 of the power system 3 via a communication line 91. The communication line 91 may be a dedicated line for wired or wireless communication, an internet line, a telephone line, or the like. The online data receiving unit 111 receives measurement data D11 from the measuring devices 61 and 71. The measurement data D11 is data indicating the temperature, power, voltage, current, and frequency of the transformer 6 measured by the measuring device 61, and data indicating the temperature, power, voltage, current, and frequency of the power transmission line 7 measured by the measuring device 71.

[0025] The online data receiving unit 111 also receives weather data D12 and wind condition measurement data D13. The weather data D12 includes, for example, at least one of Japan Meteorological Agency forecast data, weather forecast GPV (Grid Point Value) data, weather forecast SCW site (Super C Weather) data, meteorological reanalysis data such as ERA-5, and data on the results of WRF (Weather Research and Forecasting) analysis such as numerical weather models. Japan Meteorological Agency forecast data is data predicted by the Japan Meteorological Agency. Weather forecast GPV data is past and future weather forecast data calculated by a supercomputer at preset grid points on a map. ERA-5 data is data used for weather forecasting by the European Centre for Medium-Range Weather Forecasts. WRF is a forecasting model for predicting wind conditions such as wind speed and direction.

[0026] The wind condition measurement data D13 includes at least one of Japan Meteorological Agency observation data and local wind condition measurement data. Japan Meteorological Agency observation data is data obtained by measuring weather information such as wind conditions, temperature, humidity, and air pressure by the Japan Meteorological Agency. Local wind condition measurement data is data obtained by measuring wind conditions other than the Japan Meteorological Agency observation data. Local wind condition measurement data is wind condition data measured, for example, by LiDAR (Light Detection and Ranging). LiDAR is a measuring instrument that emits laser light into the atmosphere, receives scattered light from the atmosphere, and observes wind speed and direction from the Doppler frequency.

[0027] Furthermore, the receiver 11 receives supply and demand plan data D14 from an external device (not shown). The supply and demand plan data D14 is data that indicates a power generation plan and a demand forecast value, for example, every 30 minutes or every 5 minutes, for the power generators 4a, 4b and the renewable energy power generation device 5. The supply and demand plan data D14 may be transmitted from the power control device 8.

[0028] The offline data receiving unit 112 receives map data D15 and object data D16 from an external source. The map data D15 is, for example, a map of the evaluation area including the power transmission line 7 and data related to the topography, such as elevation. The object data D16 is data related to objects present in the evaluation area. This object data D16 includes data on objects that affect the heat capacity of the power transmission line 7, such as the structure of the steel tower 30 for attaching the power transmission line 7, the height and type of trees 40 growing around the power transmission line 7, and the type and number of conductors of the power transmission line 7.

[0029] The receiving operations of the online data receiving unit 111 and the offline data receiving unit 112 are controlled by the calculation unit 13. The online data receiving unit 111 and the offline data receiving unit 112 transfer the received data to the calculation unit 13.

[0030] The transmitter 12 is configured with a transmission circuit. The transmitter 12 is connected to the power control device 8 via a communication line 93. The communication line 93 may be a dedicated line for wired or wireless communication, an internet line, a telephone line, or the like. The transmitter 12 is also connected to the calculation unit 13. The transmitter 12 transmits the power flow value data D21, margin data D22, power generation plan data D23, plan correction data D24, control command data D25, and bottleneck data D27 created by the calculation unit 13 to the power control device 8.

[0031] The display unit 15 is configured by a liquid crystal display, a plasma display, etc. The display unit 15 displays various data created by the calculation unit 13.

[0032] The calculation unit 13 is configured by a computer. The calculation unit 13 is connected to the receiving unit 11, the transmitting unit 12, the memory unit 14, and the display unit 15. The calculation unit 13 has a power flow value calculation unit 21, a margin calculation unit 22, a power generation plan creation unit 23, a plan correction unit 24, a control command creation unit 25, a wind condition estimation unit 26, and a bottleneck identification unit 27. Each unit is configured by a calculation unit within the computer or a software module.

[0033] Power flow value calculation unit 21 generates power flow value data D21 based on measurement data D11 and rated data F1. The rated data F1 is data related to the rated power and upper limit temperature of transformer 6 and transmission line 7. The rated data F1 is stored in memory unit 14 in advance.

[0034] The power flow value data D21 is created by calculating the power that will keep the temperatures of the transformer 6 and the transmission line 7 at or below a predetermined upper limit temperature, without being limited by the rated power of the transformer 6 and the transmission line 7. The created power flow value data D21 is stored in the memory unit 14.

[0035] Based on the power flow value data D21 calculated by the power flow value calculation unit 21, the margin calculation unit 22 calculates the margin for each of the transformers 6a-6e and each of the transmission lines 7a-7e of the power systems 3a-3e, and generates margin data D22. The margin data D22 indicates the margin for each of the transformers 6a-6e and each of the transmission lines 7a-7e when the power indicated in the power flow value data D21 is transmitted through the power systems 3a-3e. The generated margin data D22 is stored in the memory unit 14.

[0036] The power generation plan creation unit 23 creates power generation plan data D23 based on the supply and demand plan data D14, the current flow value data D21, and the margin data D22. The supply and demand plan data D14 is data that indicates power generation plans for the generators 4a, 4b and the renewable energy power generation device 5, for example, every 30 minutes or every 5 minutes in the present or future.

[0037] Based on the power flow value data D21 and the margin data D22, the electric power that will keep the temperatures of the transformer 6 and the power transmission line 7 at or below the upper limit temperature is calculated, and the supply and demand plan data D14 is modified to create power generation plan data D23. The created power generation plan data D23 is stored in the storage unit 14.

[0038] The plan correction unit 24 creates plan correction data D24 based on the weather data D12 and the power generation plan data D23 created by the power generation plan creation unit 23.

[0039] When it is predicted that the temperature of the power transmission line 7 will change from the upper limit temperature indicated in the rated data F1 due to an accident occurring in the power grid 3, a rise in current due to an increase in the output of the renewable energy power generation device 5, a sudden change in weather, or the like, the plan correction unit 24 recalculates the power at which the temperature of the power transmission line 7 will be equal to or lower than the upper limit temperature indicated in the rated data F1, based on the wind conditions estimated by the wind condition estimation unit 26. Based on the recalculated power, the power generation plan data D23 is corrected and plan correction data D24 is created. The created plan correction data D24 is stored in the memory unit 14.

[0040] The control command creating unit 25 creates control command data D25 based on the power generation plan data D23 created by the power generation plan creating unit 23 or the plan correction data D24 created by the plan correcting unit 24.

[0041] The control command data D25 is data indicating control for supplying the power indicated in the power generation plan data D23 or the plan correction data D24 in the power grids 3a to 3e. The control command data D25 instructs, for example, control of the power generation amount of the generator 4 or the renewable energy power generation device 5. The control command data D25 may also instruct a change in the interruption current value of a protective relay (not shown in the figure) that determines the interruption of current in the power grids 3a to 3e. The created control command data D25 is stored in the storage unit 14.

[0042] The wind condition estimation unit 26 estimates wind conditions by performing airflow analysis of the evaluation target area. For example, the wind condition estimation unit 26 calculates wind conditions, such as wind speed and wind direction, in the evaluation target area using the weather data D12 and wind condition measurement data D13 received by the online data receiving unit 111, and the map data D15 and object data D16 received by the offline data receiving unit 112, and identifies the wind speed and direction that affect the thermal capacity of the power transmission line 7 based on the calculation results.

[0043] The bottleneck identification unit 27 identifies a section that will become a bottleneck within the section D of the power transmission line 7 that is separated by the steel tower 30. In this embodiment, the bottleneck identification unit 27 identifies the section D where the maximum power flow value is the lowest as the bottleneck section.

[0044] The storage unit 14 is configured with a storage medium such as a semiconductor memory or a hard disk. The storage unit 14 is connected to the calculation unit 13. The calculation unit 13 controls the writing and reading of data to and from the storage unit 14. The storage unit 14 stores preset rated data F1. The storage unit 14 also stores power flow value data D21, margin data D22, power generation plan data D23, plan correction data D24, control command data D25, and airflow analysis data D26.

[0045] Next, the power control device 8 will be described. The power control device 8 is a device that actually controls the power system 3. As shown in FIG. 1 , the power control device 8 is connected to the power system 3 via a communication line 92, and is also connected to the power system monitoring device 1 via a communication line 93. The power control device 8 is configured by a computer or the like. The power control device 8 is installed in a substation of a general electricity transmission and distribution company that monitors or controls the power system 3.

[0046] The power control device 8 instructs the control of the power generation amount of, for example, the generator 4 and the renewable energy power generation device 5 based on the supply and demand plan data D14. The power control device 8 also receives power flow value data D21, margin data D22, power generation plan data D23, plan correction data D24, and control command data D25 from the power system monitoring device 1. The power control device 8 controls the power system 3 by referring to the power flow value data D21, margin data D22, power generation plan data D23, plan correction data D24, and control command data D25.

[0047] The operation of the above-described power system monitoring device 1 for monitoring the power system 3 will be described below.

[0048] FIG. 4 is a flowchart showing the procedure of the operation of the power system monitoring device 1 according to this embodiment to monitor the power system.

[0049] In the flowchart shown in FIG. 4, first, the receiving unit 11 receives data necessary for monitoring operation (step S11). In step S11, the online data receiving unit 111 receives the measurement data D11, weather data D12, wind condition measurement data D13, and supply and demand plan data D14. In addition, the offline data receiving unit 112 receives the map data D15 and object data D16. The data received by the online data receiving unit 111 and the offline data receiving unit 112 are transferred to the calculation unit 13. The calculation unit 13 causes the receiving unit 11 to acquire the measurement data D11, weather data D12, wind condition measurement data D13, and supply and demand plan data D14 in predetermined time units, such as 1 minute, 5 minutes, or 30 minutes.

[0050] In the calculation unit 13, the wind condition estimation unit estimates the wind conditions in the area to be evaluated (step S12). Here, the operation of step S12 will be described in detail below with reference to FIG.

[0051] 5 is a diagram for explaining the details of the wind condition estimation operation. First, the wind condition estimation unit 26 creates a wide-area analysis model using the map data D15 (step S121). The wide-area analysis model shows a topographical model of mountainous areas and flatlands in a wide area including the evaluation target area where the power transmission line 7 is installed.

[0052] Next, the wind condition estimation unit 26 inputs the meteorological data D12 into a wide-area analysis model to perform airflow analysis of the wide area (step S122). In step S122, for example, ERA-5 data is used as the meteorological data D12. This ERA-5 data includes not only meteorological data for the evaluation target area but also meteorological data for outside the evaluation target area.

[0053] FIG. 6 is a graph showing an example of airflow analysis data for a wide area. In FIG. 6, the horizontal axis represents wind speed at a certain point, and the vertical axis represents altitude at a certain point. In the graph shown in FIG. 6, in normal years, wind speed increases rapidly in the positive direction as altitude increases. In contrast, in abnormal weather, wind speed first increases in the negative direction until altitude reaches a certain value, and then increases in the positive direction. In this way, the manner in which airflow analysis data changes differs between normal years and abnormal weather. Therefore, airflow analysis data for normal years and airflow analysis data for abnormal weather may be stored as separate airflow analysis data D26. In this case, airflow analysis data can be classified and managed according to the season.

[0054] Next, the wind condition estimation unit 26 creates a local analysis model using the map data D15 and the object data D16 (step S123). In step S123, the wide area is divided into a plurality of local areas, and the local analysis model includes a topographical model of each local area plus data on trees 40, steel towers 30, etc. that affect the wind conditions around the power transmission line 7.

[0055] Next, the wind conditions estimation unit 26 inputs the results of the airflow analysis of the wide area performed in step S122 into the local analysis model to perform airflow analysis of each local area (step S124). Airflow analysis data indicating the analysis results of each local area is stored in the storage unit 14 as airflow analysis data D26.

[0056] In the airflow analysis of step S124, the wind condition estimation unit 26 analyzes the influence of objects such as the steel tower 30 and trees 40 on the wind conditions of the power transmission line 7. For example, wind speed varies depending on altitude, as shown in FIG. 6. Therefore, the wind conditions of the power transmission line 7 also vary depending on the height from the ground, that is, the height of the steel tower 30 to which the power transmission line 7 is attached. Therefore, the wind condition estimation unit 26 identifies, for example, the height of the steel tower 30 as the height of the power transmission line 7, and derives the wind speed corresponding to the identified height from the results of the airflow analysis of the wide area.

[0057] Furthermore, the wind conditions for the power line 7 may also vary depending on the height and type of trees 40 standing around the power line 7. For example, the wind speed for the power line 7 may differ depending on whether the trees 40 are broad-leaved trees or coniferous trees. Furthermore, the wind speed for the power line 7 may differ depending on the season whether the trees 40 are evergreen trees or deciduous trees. Therefore, in this embodiment, the wind condition estimation unit 26 calculates a correction coefficient using a model formula in which the height and type of trees 40 are previously quantified as parameters. This correction coefficient quantifies the influence of the power line 7 on the wind conditions. By correcting the wind speed at the height of the power line, which is derived based on the results of airflow analysis of a wide area, with this correction coefficient, the wind conditions for the power line 7 can be analyzed with high accuracy.

[0058] Next, the wind condition estimation unit 26 calculates a conversion factor for converting the airflow analysis value into a measured wind condition value or a predicted wind condition value (step S125). The conversion factor is also stored in the storage unit 14 as airflow analysis data D26. The conversion factor can be calculated, for example, by calculating the difference, normalization, sum of squares of the difference, or inner product between the measured wind condition data D13 measured at a certain location and the analytical value of the airflow analysis data at the same location. The conversion factor can also be used to calculate measured wind conditions at locations where wind conditions have not been measured. The wind condition estimation unit 26 may calculate conversion factors at multiple locations. In this case, when calculating the measured wind condition value at a certain location, the conversion factor corresponding to the location closest to the location can be used to calculate the measured wind condition value with high accuracy. Alternatively, the measured wind condition value at a certain location may be calculated based on the conversion factors of multiple measured locations.

[0059] When the airflow analysis is completed as described above, the wind condition estimation unit 26 estimates the wind conditions in the evaluation area (step S126). In step S126, as shown in FIG. 5, the wind condition estimation unit 26 estimates the wind conditions in each section D of the power transmission line 7 in the evaluation area using the meteorological data D12, the wind condition measurement data D13, and the airflow analysis data D26. When estimating the current wind conditions, for a section D for which current wind condition measurement data D13 exists, the wind condition estimation unit 26 estimates the wind conditions using, for example, the wind condition measurement data D13. For a section D for which current wind condition measurement data D13 does not exist, the wind condition estimation unit 26 estimates the wind conditions using, for example, the meteorological data D12 for the vicinity of that section and the airflow analysis data D26. Furthermore, when estimating future wind conditions, the wind condition estimation unit 26 estimates wind conditions using weather data D12 including weather forecast data such as weather forecast GPV data, and airflow analysis data D26.

[0060] As described above, when wind condition estimation unit 26 estimates wind conditions for transmission line 7, which is one of the power transmission and distribution facilities, power flow value calculation unit 21 of calculation unit 13 calculates the maximum power flow value for each of power systems 3a to 3e, as shown in Fig. 3 (step S13). The maximum power flow value is calculated for each of power systems 3a to 3e, which is a predetermined range of power systems 3. The maximum power flow value is the maximum power or maximum current that can be tolerated by power systems 3a to 3e. The calculated maximum power flow value is stored in memory unit 14 as power flow value data D21.

[0061] The rated power of the transformers 6 and transmission lines 7, which are power transmission and distribution equipment located in the power systems 3a to 3e, is defined by the rating data F1. The rated power indicated in the rating data F1 is defined as a value that adds a margin to the value that the power transmission and distribution equipment can transmit and distribute at a certain temperature. Therefore, the transformers 6 and transmission lines 7 can tolerate power greater than the rated power, depending on conditions such as the ambient temperature. The power greater than the allowable rated power is referred to as the maximum power flow value.

[0062] For example, the transformer 6a and the transmission line 7a arranged in the power system 3a can tolerate power corresponding to the maximum power flow value when the temperature of the transformer 6a and the transmission line 7a is equal to or lower than the upper limit temperature indicated in the rating data F1. The upper limit temperature of the transformer 6a and the transmission line 7a is determined by the component with the lowest upper limit temperature among the components that make up the transformer 6a and the transmission line 7a. For example, the upper limit temperature of the transformer 6a and the transmission line 7a is determined based on the upper limit temperature of the insulating material that constitutes them.

[0063] The maximum power flow value of the power system 3a is calculated based on the difference between the current temperature and the upper limit temperature of the transformer 6a and the transmission line 7a. The temperatures of the transformer 6a and the transmission line 7a fluctuate based on the ambient air temperature, wind speed, amount of solar radiation, etc. around the transformer 6a and the transmission line 7a. For example, the relationship between the upper limit temperature of the transmission line 7 and the maximum power flow is shown in (Equation 1). When the upper limit temperature is input based on (Equation 1), the maximum power flow value (equivalent to the maximum current value) appropriate for the assumed weather conditions is calculated. (Equation 1) is an equation (steady-state equation) at the equilibrium point where the heat inflow term and the heat outflow term are balanced, but it is also possible to use a differential equation (transient state equation) used when the heat inflow term and the heat outflow term are not balanced just before the equilibrium point is reached.

number

[0064] Convection loss q shown in equation (1) c is the forced convection q c1 , q c21 and natural convection q cn The larger value of the two is used. Here, the forced convection q c1 , q c21 can be expressed by the following equation (2).

number

[0065] In equation (2), the Reynolds number N Re can be expressed by the following equation (3).

number

[0066] Also, natural convection q cn can be expressed by the following equation (4).

number

[0067] In addition, the radiation loss q shown in equation (1) r can be expressed by the following equation (5).

number

[0068] Furthermore, the solar heat absorption q shown in Eq. (1) s can be expressed by the following equation (6).

number

[0069] The power flow value calculation unit 21 calculates the maximum power flow value at which both the transformer 6a and the power line 7a are below their upper limit temperatures and at which at least one of the transformer 6a and the power line 7a is above its rated value, based on data relating to the current temperature, amount of solar radiation, etc. shown in the weather data D12, the upper limit temperatures of the transformer 6a and the power line 7a shown in the rated data F1, the current temperatures of the transformer 6a and the power line 7a shown in the measured data D11, and the wind speed estimated by the wind condition estimation unit 26. For example, the convection loss q c and radiation loss q rThe value of is set based on the wind speed estimated by the wind condition estimation unit 26.

[0070] The maximum power flow value is calculated without being limited by the rated power indicated in the rated data F1. Power flow value calculation unit 21 of operation unit 13 calculates the maximum power flow value for each of power systems 3a-3e at intervals of, for example, 1 minute, 5 minutes, or 30 minutes, in response to ever-changing weather conditions. Furthermore, in power systems 3a-3e, the maximum power flow value is calculated for each section D of transmission line 7.

[0071] The maximum power flow value may be calculated as the power flow value at which the upper limit temperature of the transformer 6a or the power transmission line 7a is reached after a predetermined time. For example, the power flow value calculation unit 21 may calculate the maximum power flow value as the power flow value at which the upper limit temperature of the transformer 6a or the power transmission line 7a is reached after 1 minute, 5 minutes, or 30 minutes, which corresponds to the time period of the power generation plan.

[0072] Even when power is supplied to the transformer 6a or the power transmission line 7a at a power flow value exceeding the rated power, it takes time for the transformer 6a or the power transmission line 7a to reach the upper limit temperature. Therefore, the power flow value exceeding the rated power corresponding to a predetermined time can be set as the maximum power flow value. By calculating the maximum power flow value in this way, it is possible to supply larger power to the power grids 3a to 3e.

[0073] FIG. 7 is a diagram showing an example of a display image of the maximum power flow value for each section of the power line 7 and the airflow analysis results of the wind condition estimation unit 26. As shown in FIG. 7, the display unit 15 draws the power line 7 on a map. The display unit 15 also displays the maximum power flow value of the power line 7 calculated for each section D by the power flow value calculation unit 21 in different colors according to its magnitude. In FIG. 7, as the maximum power flow value increases, the color changes in the order blue, green, and red. However, the correspondence between the magnitude of the maximum power flow value and the display color is not limited to this.

[0074] Furthermore, the display unit 15 displays on the map a wind condition map (a contour map of wind speed and wind direction) of the evaluation area M obtained by the airflow analysis of the wind condition estimation unit 26. At this time, the wind condition estimation unit 26 extracts, from the airflow analysis results, wind speed components perpendicular to the conductors in the power transmission line 7 that affect the heat capacity. The display unit 15 displays the vertical wind speed in different colors depending on the magnitude of the vertical wind speed.

[0075] The vertical wind speed can be calculated using a simple trigonometric function based on the angle between the conductor and the wind direction. For example, the IEEE (Institute of Electrical and Electronics Engineers) standard uses the wind direction coefficient K using the following equation (7) to calculate the wind speed component effective for conductor cooling, taking the wind direction into consideration. angle The wind condition estimation unit 26 can calculate the calculated wind direction coefficient K angle The wind speed component perpendicular to the conductor is extracted by multiplying the wind speed by .

number

[0076] In this embodiment, as the wind speed increases, the color changes in the order of blue, green, and red, as shown in Fig. 7. However, the correspondence between the wind speed and the display color is not limited to this.

[0077] As described above, once power flow value calculation unit 21 has calculated power flow value data D21, bottleneck identification unit 27 of operation unit 13 identifies a bottleneck section from sections D of power transmission line 7, as shown in FIG. 4 (step S14). In step S14, bottleneck identification unit 27 identifies, among each section D of power transmission line 7, the section in which the maximum power flow value calculated by power flow value calculation unit 21 is lowest as the bottleneck section. For example, in the example shown in FIG. 7, the maximum power flow value of section D2 is lower than the maximum power flow of section D1, and therefore bottleneck identification unit 27 identifies section D2 as the bottleneck section.

[0078] Next, margin calculation unit 22 of operation unit 13 calculates, for each power transmission and distribution facility, a margin with respect to the upper limit temperature when power corresponding to the maximum power flow value calculated by power flow value calculation unit 21 is supplied (step S15). The margin is calculated, for example, for each transformer 6 and transmission line 7 of power systems 3a to 3e. The calculated margin is stored in storage unit 14 as margin data D22.

[0079] 8 is a diagram showing an example of margin data D22. The margin is calculated as the amount of power or current that can be further tolerated until the power transmission / distribution equipment reaches its upper limit temperature, based on the difference between the temperature of the power transmission / distribution equipment when power corresponding to the calculated maximum power flow value is supplied and the upper limit temperature.

[0080] In the example shown in Figure 8, when power corresponding to the maximum power flow value in power system 3a is supplied, the temperature of transformer 6a reaches the upper limit temperature of 95°C, and the margin of transformer 6a becomes zero. On the other hand, when power corresponding to the maximum power flow value is supplied, if the predicted temperature of transmission line 7a is 80°C, there is a margin of 10°C below the upper limit temperature of 90°C, and the margin of transmission line 7a is, for example, 100 MW. However, when calculating the margin of transmission line 7a, the maximum power flow value of the bottleneck section identified by bottleneck identification unit 27 is used as power flow value data D21.

[0081] 9 is a diagram showing an example of a margin display. The margin calculation unit 22 creates margin data D22 by color-coding the margin for each transformer 6 and power transmission line 7 of the power systems 3a to 3e. The created margin data D22 is displayed on the display unit 15. For example, when power corresponding to the maximum power flow value is supplied, the margin calculation unit 22 creates the margin data D22 so that the display unit 15 displays in blue the power transmission and distribution equipment that is equal to or less than the rated power indicated in the rated data F1, in orange the power transmission and distribution equipment that is equal to or more than the rated power but below the upper limit temperature, and in red the power transmission and distribution equipment that is equal to or more than the upper limit temperature.

[0082] As described above, when the margin calculation unit 22 creates the margin data D22, the power generation plan creation unit 23 of the calculation unit 13 creates power generation plan data D23 based on the supply and demand plan data D14, the power flow value data D21, and the margin data D22 (step S16), as shown in Fig. 4. The created power generation plan data D23 is stored in the storage unit 14.

[0083] The power generation plan data D23 is data that plans the amount of power to be generated by the power generation facility, for example, up to five minutes in the future. The supply and demand plan data D14 is data that indicates the power generation plans of the generators 4a and 4b and the renewable energy power generation device 5, for example, every five minutes, in the present or future.

[0084] The power generation plan creation unit 23 calculates the power that will keep the temperatures of the transformer 6 and the transmission line 7 below the upper limit temperature based on the power flow value data D21 and the margin data D22, and creates the power generation plan data D23 by modifying the supply and demand plan data D14.

[0085] The power generation plan data D23 is created by adjusting the amounts of power generated by the generators 4a, 4b and the renewable energy power generation device 5 indicated in the supply and demand plan data D14. When it is predicted that the transformer 6 or the transmission line 7 will reach its upper limit temperature, that is, when the margin of the transformer 6 or the transmission line 7 is less than zero, the optimal output of the generators 4a, 4b and the renewable energy power generation device 5 is calculated by power flow calculation, and the power generation plan data D23 is created.

[0086] The power generation plan data D23 is created including an increase or decrease in the output power of the generators 4a, 4b and the renewable energy power generation device 5. The amounts of power generated by the generators 4a, 4b and the renewable energy power generation device 5 shown in the power generation plan data D23 are calculated, for example, by power flow calculation so as to minimize the overall power loss in the power system 3. The amounts of power generated by the generators 4a, 4b and the renewable energy power generation device 5 shown in the power generation plan data D23 may be calculated so as to minimize the power cost in the power system 3. The amounts of power generated by the generators 4a, 4b and the renewable energy power generation device 5 shown in the power generation plan data D23 are created by determining the transient stability, voltage stability, and frequency stability of the power systems 3a to 3e with priority over the margins shown in the margin data D22 for the transformers 6 and the transmission lines 7. Alternatively, the transient stability, voltage stability, and frequency stability of the power systems 3a to 3e may be compared with the margins indicated in the margin data D22 of the transformer 6 and the transmission line 7, and the minimum margin among them may be determined.

[0087] Next, the plan correction unit 24 corrects the power generation plan data D23 created by the power generation plan creation unit 23 to create plan correction data D24 (step S17). The plan correction unit 24 may correct the power generation plan data D23 based on the wind conditions estimated by the wind condition estimating unit 26 to create the plan correction data D24. The created plan correction data D24 is stored in the storage unit 14.

[0088] If it is predicted that the temperature of the power transmission line 7 will exceed the upper limit temperature indicated in the rated data F1 due to a sudden change in weather, etc., the plan correction unit 24 recalculates the power that will cause the temperature of the power transmission line 7 to be below the upper limit temperature indicated in the rated data F1 based on the measurement data D11 and the estimation results of the wind condition estimation unit 26.

[0089] Based on the recalculated power, the power generation plan data D23 is corrected to generate plan correction data D24. Furthermore, if it is predicted that the temperature of the power transmission line 7 will be equal to or higher than the upper limit temperature indicated in the rated data F1, an alarm is output from the display unit 15 and the transmission unit 12. The display unit 15 may be configured to include a visual alarm device such as an alarm lamp or an audio alarm device, and the alarm may be output by these alarm devices.

[0090] Furthermore, an accident or the like may limit the amount of power supply in the entire power system 3. For example, if an accident occurs and power system 3b in the power system 3 becomes unable to supply power, the amount of power supply in the power systems 3a and 3c may be increased in order to maintain the amount of power supply in the entire power system 3. In this case, the plan correction data D24 is created by adjusting the amounts of power generated by the generator 4a and the renewable energy power generation device 5.

[0091] The plan correction unit 24 determines whether the margin of the transformers 6 or transmission lines 7 of the power systems 3a and 3c will be less than zero if the power supply amount of the power systems 3a and 3c is increased. If the margin of the transformers 6 or transmission lines 7 will be less than zero in both power systems 3a and 3c, the plan correction unit 24 calculates the output power of the generators 4a and renewable energy power generation devices 5 by power flow calculation, and creates plan correction data D24 that limits the output power of the generators 4a and renewable energy power generation devices 5. The plan correction data D24 is created so that the transformers 6 or transmission lines 7 of the power systems 3a and 3c supply power equivalent to a margin of zero.

[0092] The plan correction data D24 is created to include an increase or decrease in the output power of the generators 4a, 4b and the renewable energy power generation device 5. The plan correction data D24 is created by determining the transient stability, voltage stability, and frequency stability of the power systems 3a to 3e with priority over the margins indicated in the margin data D22 for the transformers 6 and the transmission lines 7. Alternatively, the transient stability, voltage stability, and frequency stability of the power systems 3a to 3e may be compared with the margins indicated in the margin data D22 for the transformers 6 and the transmission lines 7, and the plan correction data D24 may be created by determining the minimum margin among them.

[0093] The control command creation unit 25 creates control command data D25 based on the power generation plan data D23 created by the power generation plan creation unit 23 or the plan correction data D24 created by the plan correction unit 24 (step S18). The created control command data D25 is stored in the storage unit 14.

[0094] The control command data D25 is data indicating control for supplying power in the power grids 3a to 3e according to the power generation plan data D23 created by the power generation plan creation unit 23 or the plan correction data D24 created by the plan correction unit 24. The control command data D25 instructs control of the power generation amount of the generator 4 and the renewable energy power generation device 5, for example. The control command data D25 may also instruct a change in the interruption current value of a protective relay (not shown) that determines whether to interrupt the current in the power grids 3a to 3e.

[0095] The transmitter 12 transmits the power flow value data D21, margin data D22, power generation plan data D23, plan correction data D24, and control command data D25 created by the calculator 13 to the power control device 8.

[0096] The power control device 8 receives the power flow value data D21, margin data D22, power generation plan data D23, plan correction data D24, and control command data D25 transmitted from the transmitter 12 of the power system monitoring device 1. The power control device 8 controls the power system 3 by referring to the power flow value data D21, margin data D22, power generation plan data D23, plan correction data D24, and control command data D25.

[0097] The power control device 8 issues instructions to control the amount of power generated by the power generators 4a and 4b and the renewable energy power generation device 5, for example, based on the control command data D25.

[0098] According to the present embodiment described above, the target range of the airflow analysis by the wind condition estimation unit 26 includes the power transmission and distribution equipment (power transmission line 7). Therefore, the wind conditions of the power transmission and distribution equipment can be estimated with high accuracy. As a result, the maximum power flow value of the power transmission and distribution equipment calculated by the power flow value calculation unit 21 is within a range that is equal to or greater than the rated value but does not exceed the upper limit of the thermal capacity. Therefore, it is possible to increase the transmission capacity of the power system while ensuring the reliability of the power transmission and distribution equipment.

[0099] Furthermore, in this embodiment, the bottleneck identification unit 27 identifies the bottleneck section based on the wind condition estimation and the calculation results of the maximum power flow value for each section of the power transmission line 7. This makes it possible to calculate the maximum power flow value after grasping the status of the power transmission line 7 in more detail. This makes it possible to increase the transmission capacity of the power system while improving the reliability of the power transmission and distribution equipment.

[0100] The power generation plan creation unit 23 may calculate the output of the generator 4 and the renewable energy power generation unit 5, which are power generation facilities that do not reach the upper limit temperature, based on the results of the power flow calculation, using at least one of minimizing power transmission and distribution losses, minimizing the power generation cost of the power generation facilities, maximizing the output of the renewable energy power generation facilities, and minimizing carbon dioxide emissions from the power generation facilities as an objective function, and create power generation plan data D23. In this case, the power flow value calculation unit 21 calculates the distribution of the occurrence rate of each wind speed bin as shown in FIG. 10 based on the time variation of the wind condition estimation results from the wind condition estimation unit 26. Furthermore, the power flow value calculation unit 21 calculates the probability distribution of the maximum power flow value based on the calculated occurrence rate. The power generation plan creation unit 23 also calculates the expected value of the objective function based on the probability distribution of the maximum power flow value. By configuring in this way, the output of the power generation equipment, namely the generator 4 and the renewable energy power generation equipment 5, can be calculated, including minimizing transmission and distribution losses, minimizing the power generation costs of the power generation equipment, maximizing the output of the renewable energy power generation equipment, and minimizing carbon dioxide emissions from the power generation equipment, thereby enabling more stable control of the power grid 3.

[0101] Here, with reference to Figures 11(a) to 11(c), the calculation method of the expected value will be described. Figure 11(a) is an example of a distribution map of the occurrence probability of each wind speed. This occurrence probability is calculated based on the distribution of the occurrence ratio of each wind speed bin shown in Figure 10. Figure 11(b) is an example of a distribution map of the occurrence probability of the angle formed by the conductor of the transmission line 7 corresponding to the wind direction. Figure 11(c) is an example of a distribution map of the occurrence probability of the allowable current of the transmission line 7. The power flow value calculation unit 21 substitutes the wind speed and angle shown in the distribution map of Figures 11(a) and 11(b) into the above formula (1) to calculate the occurrence probability of the allowable current shown in Figure 11(c). Next, the power flow value calculation unit 21 calculates the expected value of the objective function using the formula Σ (objective function corresponding to the allowable current × occurrence probability).

[0102] Furthermore, the power generation plan creation unit 23 may calculate the output of the generator 4 and the renewable energy power generation device 5, which are power generation facilities that do not reach an upper limit temperature based on the results of the power flow calculation, based on at least one limit value of transient stability, voltage stability, and frequency stability, and create the power generation plan data D23. With this configuration, the output of the generator 4 and the renewable energy power generation device 5, which are power generation facilities, is calculated with transient stability, voltage stability, and frequency stability ensured, so that more stable control of the power system 3 can be performed.

[0103] Furthermore, the plan correction unit 24 may correct the power generation plan data and create plan correction data that limits the output power of the power generator 4 and renewable energy power generation device 5, which are power generation facilities, when it determines that the margin of at least one of the power transmission and distribution facilities, the transformer 6 and the transmission line 7, will be less than zero due to an increase in power flow caused by a decrease in the number of operating lines due to a failure in the power system 3. With this configuration, even if there is an increase in power flow due to a decrease in the number of operating lines caused by a failure in the power system 3, it is possible to calculate appropriate output power of the power generation facilities, the generator 4 and the renewable energy power generation device 5, and to control the power system 3 stably.

[0104] Furthermore, power flow value calculation unit 21 may calculate a confidence interval for the estimated wind conditions for each section of power line 7 based on the wind condition estimation results of wind condition estimator 26. For example, a 90% TILE value used in general wind condition evaluation may be used. If the confidence interval is greater than a certain level (if the confidence interval is wide and the risk of error is high), power flow value calculation unit 21 corrects the calculated maximum power flow value by multiplying it by a correction coefficient between 0 and 1. By making such a correction, it is possible to ensure the accuracy of the calculation of the maximum power flow value even for sections of power line 7 where the wind condition estimation by wind condition estimator 26 is unreliable.

[0105] In step S12, the wind condition estimation unit 26 may also compare the wind speed value estimated for each section of the power transmission line 7 with the actual measurement value of the measurement point closest to each section in the wind condition actual measurement data D13. The wind condition estimation unit 26 calculates, for example, the difference between this wind speed value and the actual measurement value as the estimation accuracy. For sections where this estimation accuracy is equal to or less than a predetermined value, the wind condition estimation unit 26 reconstructs the local analysis model, for example, by setting local areas more finely than the wide area. As a result, for sections of the power transmission line 7 where the estimation accuracy of the wind conditions is low, the airflow analysis is performed again, so that a certain estimation standard for the wind conditions can be ensured.

[0106] If there is a section in the power transmission line 7 where the estimation accuracy is below a predetermined value, the wind condition estimation unit 26 may identify that section as a recommended section for installing a wind condition sensor. In this case, the display unit 15 displays the recommended section for installing a wind condition sensor in a form that makes it easy to distinguish it from other sections, for example, in a different color from other sections. This makes it possible to prompt the user to calculate the maximum power current value using the measurement results of the wind condition sensor for sections in the power transmission line 7 where it is difficult to ensure the estimation accuracy of the wind conditions.

[0107] The bottleneck identification unit 27 may also identify a section of the power line 7 where the maximum power flow value is equal to or less than a threshold as a bottleneck section. In this case, the bottleneck identification unit 27 may also identify the bottleneck section as a section where the wind sensor installation is recommended. The display unit 15 may also display the section where the wind sensor installation is recommended in a form that makes it distinguishable from other sections. This can encourage the use of wind sensor measurement results to calculate the maximum power flow value with higher accuracy for sections of the power line 7 where the power flow value is unlikely to increase. If a bottleneck section is present, the wind condition estimation unit 26 may reconstruct the local analysis model by dividing the wide area into local areas that are smaller than the previous airflow analysis. In this case, the estimation accuracy of the bottleneck section is improved, thereby improving the calculation accuracy of the maximum power flow value.

[0108] (Second embodiment) The second embodiment will be described below. Here, differences from the first embodiment will be mainly described, and similarities will be omitted as appropriate. In this embodiment, part of the wind condition estimation step (S12) by the wind condition estimation unit 26 differs from the first embodiment. The wind condition estimation step according to the second embodiment will be described below.

[0109] FIG. 12 is a schematic diagram for explaining the wind condition estimation step according to the second embodiment.

[0110] In the wind condition estimation step, first, the wind condition estimation unit 26 creates a wide-area analysis model using the map data D15, as in the first embodiment (step S121).

[0111] Next, the wind condition estimation unit 26 inputs the weather data D12 or wind speed data for each altitude based on the weather data D12 into the wide-area analysis model and performs airflow analysis of the wide area A1 (step S122). In this embodiment, the weather data D12 input in step S122 uses Japan Meteorological Agency forecast data. This Japan Meteorological Agency forecast data is wind condition forecast data from the Japan Meteorological Agency for multiple weather forecast points P1 located at a predetermined interval d (e.g., 2 km). Furthermore, the wide area A1 includes not only the evaluation area, which includes the areas surrounding the steel tower 30 and the power transmission line 7, but also areas outside the evaluation area. Therefore, the input weather data D12 includes not only weather data within the evaluation area, but also weather data outside the evaluation area.

[0112] Step S122 can be realized by pre-installing existing airflow analysis software using, for example, the k-ε model or the LES model in the calculation unit 13, and having the wind condition estimation unit 26 operate in accordance with the program of that airflow analysis software.

[0113] Next, the wind condition estimation unit 26 creates a local analysis model using the map data D15 and the object data D16 (step S123). In step S123, the wide area A1 is divided into local areas A2, for example, near the power transmission line 7 and the steel tower 30. In addition, a terrain model for each local area A2 is added to the local analysis model. The terrain model for the local area A2 shows data such as the positions and heights of the steel tower 30, trees 40, and buildings in more detail than the terrain model for the wide area A1.

[0114] Next, the wind condition estimation unit 26 inputs the results of the airflow analysis of the wide area A1 performed in step S122 into the local analysis model and performs airflow analysis of each local area (step S124). Airflow analysis data indicating the analysis results of each local area A2 is stored in the storage unit 14 as airflow analysis data D26. Note that, like step S122, step S124 can also be implemented by the wind condition estimation unit 26 operating in accordance with an airflow analysis software program pre-installed in the calculation unit 13. Note that, in this embodiment, in order to generate airflow analysis data with high accuracy, so-called nesting airflow analysis is performed, in which the target area of ​​the airflow analysis is narrowed stepwise from the wide area A1 to the local area A2. However, as long as data accuracy can be ensured, airflow analysis data may be generated by a combination of wide-area airflow analysis and local airflow analysis, by wide-area airflow analysis alone, or by local airflow analysis alone. When airflow analysis data is created using only wide-area airflow analysis or only local airflow analysis, nesting-based airflow analysis is not required, which shortens the time required for airflow analysis and reduces the load on the analysis process.

[0115] Next, in this embodiment, the wind condition estimation unit 26 estimates the wind conditions on the power transmission line 7 (step S126) without calculating a conversion coefficient for converting the airflow analysis value into an actual wind condition value or a predicted wind condition value (step S125).

[0116] In step S126, the wind condition estimation unit 26 calculates the estimated wind speed E of the power line 7 for each section using the following equation (8). The wind speed estimation range can be selected, for example, by a user operation. The wind condition estimation unit 26 may also estimate the wind direction at the prediction point from the difference between the wind direction at the prediction point calculated by airflow analysis using the wind direction at the prediction point as a reference and the wind direction at the estimation point. Estimated wind speed E = Predicted value F × Average wind speed ratio α (8)

[0117] In the above formula (8), the predicted value F is the wind speed predicted value of the weather forecast point P1a included in the weather data D12. If there are multiple weather forecast points P1 around the sections D1 and D2 of the power transmission line, for example, the wind speed predicted value of the weather forecast point P1a closest to each section is used as the predicted value F in order to improve the accuracy of the wind speed estimation value E. Alternatively, a predicted value F interpolated from the weather forecast points P1 around the wind speed estimation point P2 may be used.

[0118] The average wind speed ratio α is a dimensionless coefficient calculated as the ratio of the average wind speed between the weather forecast point P1a and the wind speed estimation point P2 within the section, as shown in the following equation (9). Average wind speed ratio α = 2nd average wind speed AV2 / 1st average wind speed AV1 (9)

[0119] In equation (9), the first average wind speed AV1 is the average value of the wind speed at the weather forecast point P1a over a predetermined time step or period obtained from airflow analysis. For example, Figure 13 shows wind speed trend waveforms at the weather forecast point P1a and the wind speed estimation point P2 over a predetermined period of time obtained from airflow analysis. The first average wind speed AV1 is the average value of the wind speed trend waveform at the weather forecast point P1a.

[0120] The second average wind speed AV2 is the average value of the wind speed trend waveform at the wind speed estimation point P2.

[0121] In this embodiment, as described above, when estimating the wind conditions in each section D of the power transmission line 7, the weather data D12 is not simply subjected to airflow analysis, but the average wind speed ratio α is also used to calculate the estimated wind speed value E. This improves the accuracy of the estimated wind speed value E.

[0122] Therefore, according to this embodiment, it is possible to further improve the accuracy of estimating the wind conditions on the power transmission line 7.

[0123] Although several embodiments have been described above, these embodiments are presented only as examples and are not intended to limit the scope of the invention. The novel system described in this specification can be embodied in various other forms. Furthermore, various omissions, substitutions, and modifications can be made to the forms of the system described in this specification without departing from the spirit of the invention. The appended claims and their equivalents are intended to cover such forms and modifications that fall within the scope and spirit of the invention. [Explanation of symbols]

[0124] 1: Power system monitoring device 11: Receiving unit 15: Display section 21: Power flow calculation section 22: Margin calculation section 23: Power Generation Planning Department 26: Wind condition estimation section 27: Bottleneck Identification Unit

Claims

1. a wind condition estimation unit that estimates wind conditions for the power transmission and distribution facilities based on a result of airflow analysis of meteorological data relating to weather in an evaluation area including the power transmission and distribution facilities of the power system; a power flow value calculation unit that calculates a maximum power flow value that is equal to or greater than a predetermined rated value as a power flow value of the power transmission and distribution facility according to the estimated wind conditions of the power transmission and distribution facility; Equipped with the wind condition estimation unit estimates wind conditions for each section of the power transmission and distribution facility; the power flow value calculation unit calculates the maximum power flow value for each section; The power system monitoring device further comprises a bottleneck identification unit that identifies, as a bottleneck section, a section in the power transmission and distribution facility where the maximum power flow value is lowest.

2. 2. The power system monitoring device according to claim 1, further comprising a display unit that plots the power transmission and distribution facility on a map, displays maximum power flow values ​​of each section of the power transmission and distribution facility in different colors according to their magnitude, and displays airflow analysis results for the evaluation area on the map.

3. a receiving unit that receives the weather data in a preset time unit; the wind condition estimation unit estimates wind conditions at the power transmission and distribution facility in the time units; The power system monitoring device according to claim 1 , wherein the power flow value calculation unit calculates the maximum power flow value in the time unit for each of the power transmission and distribution facilities installed in each of a plurality of power systems.

4. a margin calculation unit that sets the maximum power flow value as an upper limit, and calculates a difference obtained by subtracting the power flow value of the power transmission and distribution facility from the upper limit as a margin for each of the power transmission and distribution facilities; The power system monitoring device according to claim 1 , further comprising: a power generation plan creating unit that creates power generation plan data for the power system so that the margin is equal to or greater than a predetermined value.

5. 2. The power system monitoring device according to claim 1, wherein the power flow value calculation unit calculates a confidence interval of wind conditions for each section of the power transmission and distribution facility based on the wind condition estimation result of the wind condition estimation unit, and corrects the maximum power flow value in accordance with the confidence interval.

6. the power flow value calculation unit calculates a probability distribution of the estimation result based on the wind condition estimation result of the wind condition estimation unit, and then calculates a probability distribution of the maximum power flow value; 5. The power system monitoring device according to claim 4, wherein the power generation plan creation unit uses at least one of minimizing power transmission and distribution losses, minimizing power generation costs of power generation facilities, maximizing output of a renewable energy power generation device, and minimizing carbon dioxide emissions from power generation facilities as an objective function, and when creating power generation plan data that does not reach an upper limit temperature of the power transmission and distribution facilities based on a result of power flow calculation, calculates an expected value of the objective function based on a probability distribution of the maximum power flow value.

7. 2. The power system monitoring device according to claim 1, wherein the wind condition estimation unit calculates an estimation accuracy of the wind conditions for each section of the power transmission and distribution facility using a result of comparing the estimated results of the wind conditions with actual measured values, and reconstructs a model used for airflow analysis for sections where the estimation accuracy is equal to or less than a predetermined value.

8. 2. The power system monitoring device according to claim 1, wherein the wind condition estimation unit calculates an estimation accuracy of the wind conditions for each section of the power transmission and distribution facility using a result of comparing the estimated results of the wind conditions with actual measured values, and identifies sections in which the estimation accuracy is equal to or less than a predetermined value as sections in which installation of a wind condition sensor is recommended.

9. the wind condition estimation unit estimates wind conditions for each section of the power transmission and distribution facility; the power flow value calculation unit calculates the maximum power flow value for each section; 2. The power system monitoring device according to claim 1, further comprising a bottleneck identification unit that identifies a section in the power transmission and distribution facility where the maximum power flow value is equal to or less than a threshold value as a bottleneck section, and identifies the bottleneck section as a section in which installation of a wind condition sensor is recommended.

10. The power system monitoring device according to claim 9 , wherein the wind condition estimating unit performs airflow analysis again for the bottleneck section by dividing the evaluation target area more finely than in the previous airflow analysis.

11. 2. The power system monitoring device according to claim 1, wherein the wind condition estimation unit estimates the wind conditions of the power transmission and distribution equipment using a predicted value of a weather forecast point in the evaluation area obtained from the weather data and a ratio of average wind speeds within a predetermined calculation step or time obtained from the airflow analysis between the weather forecast point and the power transmission and distribution equipment.

12. We analyze the weather data related to the weather in the area to be evaluated, including the power grid's transmission and distribution facilities, and Estimating wind conditions for each section of the power transmission and distribution facility based on the results of the airflow analysis; calculating, for each section, a maximum power flow value that is equal to or greater than a predetermined rated value as a power flow value of the power transmission and distribution facility according to the estimated wind conditions of the power transmission and distribution facility; identifying a section in the power transmission and distribution facility where the maximum power flow value is lowest as a bottleneck section; Power system monitoring method.

13. A process of analyzing airflow data relating to the weather in an area to be evaluated, including the power transmission and distribution facilities of the power system; A process of estimating wind conditions for each section of the power transmission and distribution facility based on the results of the airflow analysis; calculating, for each section, a maximum power flow value that is equal to or greater than a predetermined rated value as a power flow value of the power transmission and distribution facility according to the estimated wind conditions of the power transmission and distribution facility; a process of identifying a section in the power transmission and distribution facility where the maximum power flow value is lowest as a bottleneck section; A program that causes a computer to execute the following.

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