Power system management device and power system information display method

Abstract

To provide a power system management device and a power system information display method that allow a user to more clearly grasp the state of a power system.SOLUTION: And a display unit that causes the display device 15 to display a management screen 100 including a stability calculation unit that calculates steady-state stability of a power system including at least one generator, a system diagram display unit 300 that displays a power system diagram showing a configuration of the power system, and a stability display unit 500 that displays the steady-state stability of the generator, in which the stability calculation unit calculates a power phase difference angle curve of the generator and a phase difference angle of the generator, and the display unit causes the display device 15 to display the system diagram display unit 300 and the stability display unit 500 on one screen. The phase difference angle of the generator is superimposed on the power phase difference angle curve and displayed on the stability display unit 500.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a power system management device for monitoring and operating a power system and a power system information display method. [Background technology]

[0002] Conventionally, technologies for visualizing the status of a power system have been developed. For example, Patent Document 1 discloses a technology for visualizing the status of a power system by displaying a power system diagram and calculation results of allowable power flow operational values ​​on separate tabs. Furthermore, Patent Document 2 discloses a technology for displaying, on a single screen, a real-time monitor that displays the current and past status of a monitored object, important similar past cases, and an operation panel that an operator uses to operate the monitored object. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2020 / 90021 [Patent Document 2] Patent No. 6360977 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, renewable energy sources and storage batteries have been widely used, but there are concerns that the increase in the proportion of renewable energy sources will reduce the synchronization ability and inertia of the entire power system. However, conventional technologies have not yet been put into practical use to visualize the steady-state stability of power systems, and there has been a demand for a system that can monitor the steady-state stability of power systems in real time. In particular, there has been a need for a system that can centrally monitor the steady-state stability of power systems together with the power system configuration.

[0005] An object of the present invention is to provide a power system management device and a power system information display method that allow a user to more clearly understand the state of the power system. [Means for solving the problem]

[0006] A power system management device according to the present invention comprises: a stability calculation means for calculating the steady-state stability of a power system including at least one generator; a system diagram display unit for displaying a power system diagram showing the configuration of the power system; and a stability display unit for displaying the steady-state stability of the generator; and a display means for causing a display device to display a management screen having the stability calculation means for calculating the steady-state stability of the power system including at least one generator; a system diagram display unit for displaying a power system diagram showing the configuration of the power system; and a stability display unit for displaying the steady-state stability of the generator. The stability calculation means calculates a power phase difference angle curve and a phase difference angle of the generator, and the display means causes the display device to display the system diagram display unit and the stability display unit on a single screen, and also causes the stability display unit to display the power phase difference angle curve with the phase difference angle of the generator superimposed thereon. In the above power system management device, the display means can be configured to change the color of the generator to be warned in the power system diagram displayed on the system diagram display unit to an accent color when the phase difference angle of the generator is equal to or greater than a predetermined threshold and to display an alarm area in which the area inside the power phase difference angle curve and equal to or less than the phase difference angle of the generator to be warned is colored in an accent color as the steady-state stability index of the generator to be warned displayed on the stability display unit. In the above power system management device, the threshold value may be a phase difference angle set by a user in a current configuration of the power system, and / or a phase difference angle obtained by converting the phase difference angle set by the user in accordance with a change in the configuration of the power system. In the above-described power system management device, in addition to the system diagram display unit and the stability display unit, a phase difference angle transition display unit that displays time-varying phase difference angles of generators that constitute the power system, and / or a basic information display unit that displays measurement times of the phase difference angles of generators that constitute the power system can be configured to be displayed on a single screen on the display device. In the above power system management device, the phase difference angle transition display unit can be configured to display a combination of a time change in the phase difference angle of the generator and a time change in the bus voltage, active power and / or reactive power. In the above power system management device, the phase difference angle of the generator displayed on the stability display unit includes the latest phase difference angle of the generator and the phase difference angle of the generator a predetermined time ago, The latest phase difference angle of the generator may be displayed in a darker color than the phase difference angle of the generator a predetermined time ago. In the above-described power system management device, the display means may be configured to display, as the power phase difference angle curve to be displayed on the stability display unit, a power phase difference angle curve in the current configuration of the power system and a power phase difference angle curve in the event that the configuration of the power system is changed, in a superimposed manner. In the above-described power system management device, the display means can be configured to, when a user specifies a component of the power system diagram in the system diagram display unit displayed on the display device via the input means, change the configuration of the power system by excluding or adding the specified component from the configuration of the power system displayed on the system diagram display unit, and to display the power phase difference angle curve corresponding to the changed power system configuration of the power system in the stability display unit. The above-described power system management device may further include input means for a user to input instructions, and the stability calculation means may calculate a power phase difference angle curve and a phase difference angle corresponding to the generator selected by the user via the input means. The power system information display method according to the present invention comprises a stability calculation step of calculating a power phase difference angle curve of a generator in a power system including at least one generator and the phase difference angle of the generator, and a display step of displaying on a display device a management screen having a system diagram display unit that displays a power system diagram showing the configuration of the power system and a stability display unit that displays the steady-state stability of the generator, wherein the power phase difference angle curve and the phase difference angle of the generator are calculated in the stability calculation step, and the system diagram display unit and the stability display unit are displayed on a single screen in the display step, and the stability display unit is caused to display the phase difference angle of the generator superimposed on the power phase difference angle curve. In addition, the power system management device according to the present invention comprises a stability calculation means for calculating the steady-state stability of a power system including at least one generator, a system diagram display unit for displaying a power system diagram showing the configuration of the power system, and a stability display unit for displaying the steady-state stability of the generator, and a display means for causing a display device to display a management screen having the system diagram display unit and the stability display unit on a single screen. In the above-described power system management device, the stability calculation means calculates a steady-state stability index for the configuration of the power system and a steady-state stability index when the configuration of the power system is changed, and the display means draws and superimposes on the stability display unit a display showing the steady-state stability index for the configuration of the power system and a display showing the steady-state stability index when the configuration of the power system is changed. In the above power system management device, the stability calculation means calculates the steady-state stability index in a power system configuration that further includes a renewable energy power source, and the steady-state stability index when the configuration of the power system is changed. In the above-described power system management device, the stability calculation means calculates, as the steady-state stability index when the configuration of the power system is changed, the steady-state stability index when the renewable energy power source is added to the configuration of the power system. In the above power system management device, the stability calculation means calculates, as the steady-state stability index, a power phase difference angle curve showing the relationship between the power value of a predetermined generator in the power system and the phase difference angle, and the display means draws, as the steady-state stability index, a power phase difference angle curve for the configuration of the power system and a power phase difference angle curve when the configuration of the power system is changed, and displays them in a superimposed manner. In the above power system management device, the stability calculation means further calculates, as the steady-state stability index, the power value and phase difference angle of the specified generator and a steady-state stability limit which is the peak value of the power phase difference angle curve, and the display means further draws and superimposes, as the steady-state stability index, a display showing the power value and phase difference angle of the specified generator, a display showing the steady-state stability limit in the configuration of the power system, and a display showing the steady-state stability limit when the configuration of the power system is changed. The above-mentioned power system management device further includes an acquisition means for acquiring output values ​​and output time information from each component of the power system, and the stability calculation means calculates the steady-state stability based on the output values ​​output at the same time. Furthermore, the power system management method according to the present invention comprises a stability calculation step of calculating the steady-state stability of a power system including at least one generator, and a display step of displaying on a display device a management screen having a system diagram display unit that displays a power system diagram showing the configuration of the power system, and a stability display unit that displays the steady-state stability of the generator, and in the display step, the system diagram display unit and the stability display unit can be configured to be displayed on a single screen. [Effects of the Invention]

[0007] According to the present invention, a power system diagram showing the configuration of the power system and a steady-state stability index showing the steady-state stability of the generators that make up the power system are displayed on a single screen, allowing the user to more clearly understand the state of the power system. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a configuration diagram of a power system management device according to an embodiment of the present invention. [Figure 2] 1 is a diagram illustrating an example of the configuration of a power system according to an embodiment of the present invention. [Figure 3] FIG. 3 is a diagram illustrating an example in which the configuration of the power system illustrated in FIG. 2 is changed. [Figure 4] FIG. 10 is a diagram illustrating an example of a management screen displayed in the present embodiment. [Figure 5] FIG. 10 is a diagram for explaining a management screen displayed in the present embodiment. [Figure 6] FIG. 10 is a diagram for explaining a basic information display section. [Figure 7] FIG. 2 is a diagram for explaining a system diagram display unit. [Figure 8] 10 is a diagram for explaining a phase difference angle transition display unit. FIG. [Figure 9] FIG. 10 is a diagram for explaining a stability display unit. [Figure 10] FIG. 4 is a partial enlarged view showing an example of a stability display section. [Figure 11] FIG. 10 is a diagram showing another example of a screen displayed on the display device. [Figure 12] FIG. 10 is a diagram showing another example of a screen displayed on the display device. [Figure 13] FIG. 10 is a diagram showing another example of a screen displayed on the display device. [Figure 14] FIG. 10 is a diagram showing another example of a screen displayed on the display device. DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment of the present invention will be described below with reference to the drawings. The following description will be given using an example of a power system management device that allows a user who manages a power system to understand the status of the power system, including the steady-state stability of the power system. In the following, a synchronous generator, such as a nuclear power plant, a thermal power plant, or a hydroelectric power plant, will be simply referred to as a "generator." Renewable energy power sources, such as solar power plants and wind power plants, and devices connected to the power system via inverters, such as storage batteries, will be collectively referred to as "renewable energy power sources." Furthermore, generators, renewable energy power sources, power plants, and loads connected to the power system will also be collectively referred to as "components." In addition, when dealing with a phase difference angle within a generator, it may be referred to as an internal phase difference angle, but in this embodiment, it will be referred to as a "phase difference angle." In this embodiment, a manager or operator who manages and operates the power system uses the power system management device according to this embodiment. In the following, such a manager or operator will be referred to as a "user."

[0010] A power grid is a system that transports and distributes electrical energy through (1) renewable energy sources and storage batteries, such as solar and wind power, (2) substations, power plants, and / or power plants, which are connected to nuclear power plants, thermal power plants, hydroelectric power plants, pumped-storage power plants, and geothermal power plants, and / or (3) transmission and distribution lines that electrically connect consumer locations such as factories and buildings. It is composed of various voltage classes, such as 6 kV, 22 kV, 66 kV, and 500 kV, and the combination of these classes is not limited to known forms or formats. In a power grid, energy supply equipment and energy consumption equipment are connected. When viewed as a whole, the power grid can be viewed as the transport and distribution of electrical energy between at least one generator and one consumer. Furthermore, even in a portion of the power grid, the transport and distribution of electrical energy between at least one generator and one consumer is also carried out. Generators include the various power generation forms mentioned above, such as power generation facilities, storage facilities, and inverter power supplies. There are multiple partial areas that are made up of such relationships between generators and demand, and when you look at the aggregate that is electrically connected to each other, you can think of the many generators / power generation facilities as being contracted and like one or more generators and demand. Visualizing the steady-state stability of the power system in real time / Centralized monitoring of the steady-state stability of the power system together with the power system configuration can refer to a single generator, or multiple generators, or a large number of generators can be condensed and visualized as a single generator, allowing managers to intuitively grasp the stability of the power system. Therefore, one generator can refer not only to one generator, but also to a number of generators that are electrically combined and condensed.

[0011] FIG. 1 is a configuration diagram of a power system management apparatus 10 according to this embodiment. As shown in FIG. 1, the power system management apparatus 10 according to this embodiment includes a communication device 11, a calculation device 12, a storage device 13, a database 14, a display device 15, a notification device 16, and an input device 17. In the power system management apparatus 10 according to this embodiment, a user monitors the state of the power system displayed on the display device 15, and can input user instructions to the power system management apparatus 10 by operating the input device 17 such as a mouse or keyboard. Each component of the power system management apparatus 10 will be described below.

[0012] By executing a program stored in the storage device 13, the arithmetic device 12 has an acquisition function for acquiring system constants in the power system and output values ​​of each component of the target power system, a stability calculation function for calculating the steady-state stability of the power system based on the output values ​​of each component of the power system, a display function for displaying a power system diagram of the power system and the steady-state stability of the generator on the display device 15, and a notification function for making a notification. Each function of the arithmetic device 12 will be described below.

[0013] The acquisition function of the computing device 12 acquires system constants in the power system. In this embodiment, system constants such as the impedance of power transmission lines and transformers and internal constants of generators are pre-stored in the database 14, and the acquisition function can acquire these system constants of the power system from the database 14. In this embodiment, output values ​​such as voltage, current, and generated power (hereinafter referred to as power values) of each component of the power system (such as a generator, renewable energy power source, electric power station, and load) are measured by a measuring device (not shown) connected to the power system, and the output values ​​measured by the measuring device are transmitted to the power system management device 10. This allows the acquisition function to acquire the output values ​​of each component of the power system via the communication device 11. In this embodiment, the acquisition function acquires GPS information including output time information from each measuring device connected to the power system in addition to the output values ​​of each component of the power system, thereby obtaining information on the time when each component output value was output. Note that information from each measuring device connected to the power system may be directly communicated, or may be linked via a centralized monitoring and control system such as a control center / power dispatching center.

[0014] FIG. 2 is a diagram showing an example of the configuration of a power system according to this embodiment. In the power system shown in FIG. 2, a generator G, a renewable energy power source P, and an infinite bus IB are connected via transmission lines L1 and L2. In this case, the acquisition function can acquire, as system constants of the power system, the complex impedance r1+jx1 of the transmission line L1 and the complex impedance r2+jx2 of the transmission line L2 from the database 14. In addition, the acquisition function can acquire, via the communication device 11, the voltage value V of the generator G. G and the current value I G , power generation P from renewable energy source P P , the voltage value V of the infinite bus IB IB can be obtained from a measuring device (not shown) connected to the power grid.

[0015] The stability calculation function of the arithmetic device 12 calculates the steady-state stability of the power system. Specifically, the stability calculation function first calculates the active power value P of the generator to be monitored based on the voltage value V and current value I of the generator to be monitored. For example, in the example shown in FIG. 2, if the generator to be monitored is generator G, the stability calculation function calculates the active power value P of the generator G based on the voltage value V and current value I of the generator G measured at the same sampling period. G , current value I G , and based on these phase angles, the current active power value P of the generator G is calculated. G Calculate the phase difference angle of the generator from the difference between the measured value θ of the specified distant electric power station (electric power station equivalent to an infinite bus) and the reference value θ. G Get.

[0016] The stability calculation function also calculates the steady-state stability of each generator that makes up the power system using the output values ​​of each component connected to the power system. Specifically, the stability calculation function first calculates a power phase difference angle curve that shows the relationship between the generated power value P of the generator in the current configuration of the power system and the phase difference angle θ based on a specified remote electric power station (for example, an infinite bus), and the steady-state stability limit, which is the peak value of the power phase difference angle curve, as a steady-state stability index that indicates the steady-state stability of the generator.

[0017] For example, in the example shown in Figure 2, the stability calculation function calculates the active power value P G and the phase difference angle θ of generator G G In the current configuration of the power system shown in Figure 2, the generator G, the renewable energy power source P, and the infinite bus IB are connected to the transmission lines L1 and L2, so the active power value P of the generator G is G and phase difference angle θ G Theoretically, there is a relationship shown in the following formula (1). In the following formula (1), P G +jQ G is the complex power of generator G, r1+jx1 is the complex impedance of transmission line L1, r2+jx2 is the complex impedance of transmission line L2, V G is the voltage value of generator G, V P is the voltage value of the renewable energy power source P, and θP is the phase difference angle of the renewable energy power source P, which can be calculated using the following formula (2). P is the active power value of the renewable energy source P.

number

number

[0018] The stability calculation function uses the voltage value V of generator G in the above formula (1). G , the voltage value V of the renewable energy power source P P , the voltage value V of the infinite bus IB IB , the complex impedance r1+jx1 of the transmission line L1, and the complex impedance r2+jx2 of the transmission line L2 are substituted, and the active power value P of the generator G is G and phase difference angle θ G In addition, the stability calculation function can calculate a power phase difference angle curve that shows the relationship between the effective power value P G The phase difference angle at which the peak is reached can be calculated as the steady-state stability limit.

[0019] Furthermore, in this embodiment, the stability calculation function also calculates the power phase angle curve and the steady-state stability limit when the current configuration of the power system is changed. Here, FIG. 3 is a diagram showing an example of a changed power system configuration. FIG. 3(A) shows a configuration in which a renewable energy power source P is removed from the current configuration of the power system shown in FIG. 2, and FIG. 3(B) shows a configuration in which a renewable energy power source P2 is added to the current configuration of the power system shown in FIG. 2. Also, FIG. 3(C) shows a configuration in which a renewable energy power source P2 and a load B are added to the current configuration of the power system shown in FIG. 2, and FIG. 3(D) shows a configuration in which the renewable energy power source P is removed from the current configuration of the power system shown in FIG. 2 and the load B is added. In this embodiment, the stability calculation function not only calculates the power phase angle curve and the steady-state stability limit for the current configuration of the power system shown in FIG. 2, but also calculates the power phase angle curve and the steady-state stability limit when the current configuration of the power system is changed, as shown in FIGS. 3(A) to 3(D).

[0020] Note that the power phase angle curves for the configurations shown in Figures 3(A) to 3(D) can be calculated using known methods, and therefore a detailed description thereof will be omitted. Furthermore, when the configuration of the power system is changed, the resulting configuration is not particularly limited. For example, the user can specify the changed configuration by clicking on each component in the power system diagram displayed on the display device 15 using an input device 17, such as a keyboard or a mouse. Furthermore, for output values ​​of components that cannot be measured in the power system, the influence of power flows due to renewable energy sources can be corrected and calculated using measured output values ​​of other components or known transmission line impedance. In this embodiment, the stability calculation function calculates the power phase angle curve based on output values ​​output at the same time using GPS information (including output time information) transmitted from the measurement device. However, the power phase angle curve can also be calculated using measurement values ​​measured at different sampling times, such as telemeters for power system control centers, either individually or in combination. For example, in utility facilities such as renewable energy sources, it may not be possible to install equipment that performs measurements in synchronization with measuring instruments at other power stations managed by the power system user. In such cases, the calculations can be performed without synchronizing the sampling times, assuming that there are no large fluctuations in the amount of power generated by renewable energy sources or the demand load, and the results can be displayed.In addition, since the loss due to transmission lines is small, the active power value of a non-metered electric power station can be replaced by the sum of the active power of other electric power stations.

[0021] The display function of the computing device 12 causes a plurality of pieces of information related to the power system to be displayed in an integrated manner on the display of the display device 15. FIG. 4 is a diagram showing an example of a management screen 100 displayed on the display of the display device 15. FIG. 5 is a diagram for explaining the management screen 100 displayed on the display of the display device 15. As shown in FIG. 5, in the power system management device 10 according to this embodiment, the display function displays the management screen 100, which has a basic information display section 200, a system diagram display section 300, a phase difference angle transition display section 400, and a stability display section 500, on the display of the display device 15. Each display section constituting the management screen 100 will be described below.

[0022] The basic information display unit 200 displays the time at which a measurement value was acquired by each measuring device (not shown) connected to the power grid. This time is the time acquired by the measuring device together with the measurement value by synchronization with a GPS (Global Positioning System), or the time at which the measurement value was acquired and recorded by the communication device 11 synchronized with the measuring device. When the display function receives the latest time via the communication device 11, it updates the time displayed on the basic information display unit 200 to the latest time. Furthermore, the display function displays the updated time down to the second on the basic information display unit 200. This allows the user to understand that the phase difference angle is being updated in real time.

[0023] In this embodiment, the basic information display unit 200 is provided with buttons for "Stop Alarm," "Alarm Information," "Restore Display," and "Settling." Fig. 6 is a diagram illustrating the basic information display unit 200. (A) shows a normal state (a state in which the power grid is stable and is not expected to become unstable), (B) shows a state in which the power grid is stable but is expected to become unstable due to a pre-anticipated event (e.g., the shutdown of one transmission line, an increase in power generation from a renewable energy source, a decrease in demand, etc.), and (C) shows a current unstable state. The "stable power grid" state refers to a state in which the phase difference angles θ of all generators are less than predetermined thresholds δ1 and δ2. The "unstable power grid" state refers to a state in which stable power transmission is not possible even with disturbances such as gradual load changes. When the phase difference angles θ of one or more generators connected to the power grid exceed the predetermined thresholds δ1 and δ2, the power grid approaches the unstable region. The predetermined thresholds δ1 and δ2 will be explained in the stability display section 500.

[0024] As shown in Figure 6(A), when the state of the power system is stable, the "Stop Alarm," "Alarm Information," and "Restore Display" buttons are displayed in a color indicating a normal state, such as gray, and the buttons are set to a state where they cannot be pressed. On the other hand, if the current power system is stable, but the power system is predicted to become unstable due to a predetermined event (for example, the shutdown of one transmission line, an increase in power generation by a renewable energy source, a decrease in demand, etc.), and the phase difference angle θ of one or more generators becomes equal to or greater than the second threshold value δ2 in that state, the "Alarm Information" and "Restore Display" buttons are displayed in a highlighted color such as red to indicate an abnormal state, and the "Alarm Information" button is made pressable. In this state, the user can press the "Alarm Status" button via the input device 17 to cause the display function to display a screen showing details of the abnormality on the display of the display device 15. Furthermore, if the phase difference angle θ of one or more generators exceeds the second threshold δ2 and then, due to a change in the state of the power grid, the phase difference angle θ of all generators falls below the second threshold δ2, the "Display Reset" button becomes pressable. By pressing the "Display Reset" button via the input device 17, the user can restore the display functions (basic information display section 200, system diagram display section 300, stability display section 500, buttons such as "Alarm Information" and "Display Reset" displayed in red, generator graphics on the power grid diagram, and alarm area A2 (details will be described later) to their normal state (color display such as gray). On the other hand, if the phase difference angle θ of all generators remains above the second threshold δ2, the display cannot be restored to its normal state (color display such as gray). However, as shown in FIG. 6(B), if the current power grid is stable but becomes unstable due to the occurrence of a preset event, an alarm sound is not output. Furthermore, if the phase difference angle θ of one or more generators exceeds the first threshold value δ1 and the current power grid approaches an unstable state, the "Alarm Stop," "Alarm Information," and "Display Reset" buttons are displayed in a highlighted color such as red, and all buttons except for "Display Reset" are set to a pressable state, as shown in FIG. 6(C). In this case, an alarm sound is output from the alarm device 16, and the user can stop this alarm sound by pressing the "Alarm Stop" button. Furthermore, as in the case of FIG. 6(B), in the case shown in FIG. 6(C), a screen showing details of the abnormality can be displayed by pressing the "Alarm Information" button.

[0025] 6(A) to 6(C), in this embodiment, a "setting" button is provided in the basic information display section 200. The user can display the screen shown in FIG. 6(D) by pressing the "setting" button via the input device 17. FIG. 6(D) shows an example of a screen for setting the equipment constants of each generator and the three-phase connection system of the transformers for the generators. Via this screen, the user can, for example, set the equipment constants (e.g., internal impedance) of the generator, and the equipment constants and connections (e.g., angular displacement) of the transformer.

[0026] The system diagram display unit 300 displays a power system diagram that allows the user to view the configuration of the power system. FIG. 7 is a diagram for explaining the system diagram display unit 300. In FIG. 7, "ss" indicates a substation and "ps" indicates a power plant, which are connected via a transmission line. In the power plant ps shown on the right side of FIG. 7, two generators G1 and G2 are displayed, and the power phase angle curves corresponding to the selected generator or a preselected generator are displayed on the stability display unit 500. In this embodiment, the display function draws figures representing transmission lines and transformers in the power system diagram displayed on the system diagram display unit 300 with lengths proportional to the reactance and displays them on the display device 15. This allows the administrator to intuitively understand the reactance of the transmission lines and transformers. Furthermore, according to known electrical theory, the steady-state stability of a generator is the reciprocal of the reactance, which is a physical constant of transmission lines and transformers. By displaying the transmission lines and transformers with lengths proportional to the reactance, which is a physical constant, the user can grasp the approximate steady-state stability of the generator.

[0027] As shown in FIG. 7, the display function displays the phase angle δ of each generator as a number next to a graphic representing each generator in the power system diagram displayed on the system diagram display unit 300. This allows the user to grasp the phase angle of each generator from a bird's-eye view. Note that the phase angle of a generator is an internal value calculated from measurements and is a relative value in which a distant electric power station in the power system to which the generator supplies power is used as the reference for the phase angle, with the phase of the reference electric power station being set to 0 degrees. In this way, the phase angle of a generator indicates the deviation from a reference when the phase of the distant electric power station is set to the reference (0°). By displaying the phase angle of the generator from a bird's-eye view, the user can grasp the twist in the power system. As shown in FIG. 7, the display function can also display the voltage value at each power plant and the complex power (P+jQ) of the generator as a number in the power system diagram.

[0028] Furthermore, the display function has a function of changing the configuration of the power system diagram displayed on the system diagram display unit 300 by the user operating the input device 17. Specifically, the user operates the input device 17 to specify components such as power transmission lines and transformers that configure the power system diagram displayed on the system diagram display unit 300, thereby making it possible to exclude or add the specified power transmission line or transformer from the configuration. For example, in the example shown in FIG. 7 , the user uses the input device 17 to move the pointer on the management screen 100 to the position of one of the power transmission lines that form a dual-use duplex of lines No. 1 and No. 2, and specifies power transmission line L3 (for example, by clicking the mouse), whereby power transmission line L3 is displayed in gray, for example, and the power system diagram changes to one showing a state in which power transmission line L3 is stopped. In this case, the stability calculation function recalculates the steady-state stability of each generator for the power system configuration in which transmission line L3 is stopped, and the stability display unit 500 (described later) displays the power phase angle curve for the power system configuration in which transmission line L3 is stopped as the power phase angle curve for the changed configuration. In this way, in this embodiment, the power system configuration can be changed simply by specifying the configuration of the power system diagram displayed on the system diagram display unit 300. This allows the user to quickly and easily understand the impact of changing part of the power system configuration, for example, when considering equipment shutdowns due to system accidents, maintenance, etc. Note that the user is aware of the state of the power system on a daily basis, and can change the power system configuration based on their experience or hypothetically by specifying conditions such as the shutdown of a power line or transformer.

[0029] The display function is also capable of displaying the phase difference angle θ of the generator in the power system diagram displayed on the system diagram display unit 300. G When the phase difference angle θ of the generator G2 is equal to or greater than the preset thresholds δ1 and δ2, the figure of the generator G2 is highlighted in red. G2 is less than the preset threshold δ1 and threshold δ2, the generator G1 is displayed in gray in the power system diagram, and the phase difference angle θ G1is greater than or equal to threshold δ1 or threshold δ2, the generator is displayed in red on the power system diagram. This allows the manager to clearly grasp, from a bird's-eye view, the generators whose phase difference angle θ is large and whose steady-state stability is approaching the unstable region. Details of the thresholds δ1 and δ2 will be explained in the stability display unit 500.

[0030] The phase difference angle transition display unit 400 displays a graph showing the change over time in the phase difference angle of each generator. FIG. 8 is a diagram for explaining the phase difference angle transition display unit 400. In this embodiment, the graph displayed on the phase difference angle transition display unit 400 has a horizontal axis representing time and a vertical axis representing the phase difference angle of each generator. As shown in FIG. 8(A), the phase difference angle transition display unit 400 can display the change over time in the phase difference angle of all generators connected to the power grid. Alternatively, the user can operate the input device 17 to display only the change over time in the phase difference angle of a generator desired by the user. For example, as shown in FIG. 8(B), the display function can display on the display device 15 a screen for selecting a generator to be displayed on the phase difference angle transition display unit 400. When the user selects a generator to be displayed on the phase difference angle transition display unit 400 via the input device 17, the display function can enlarge and display only the change over time in the phase difference angle of the generator selected by the user on the phase difference angle transition display unit 400, as shown in FIG. 8(C).

[0031] In this embodiment, the stability calculation function repeatedly calculates the phase difference angle of each generator every few seconds to every few minutes, and the display function plots the phase difference angle of each generator calculated by the stability calculation function on a graph in chronological order, thereby allowing the change over time in the phase difference angle of each generator to be displayed on the phase difference angle transition display unit 400. For example, the display function can display the most recent change over time in the phase difference angle (for example, in the most recent 10 seconds) on the phase difference angle transition display unit 400. This allows the user to intuitively grasp the status of the generators from the change over time in the phase difference angle of the generators.

[0032] 8(A) and 8(C), in this embodiment, the display ranges showing the time change of the phase difference angle of each generator are aligned vertically (up and down in the drawing), and the time change of the phase difference angle of each generator is displayed within this display range. The display function may also have a function to automatically adjust the scale of the display range of the phase difference angle of the generator to be displayed on the phase difference angle trend display unit 400. For example, because the output of a generator can change from zero when the generator is stopped to rated output, the display function may initially set the range of the phase difference angle from zero to the rated output (maximum value) as the display range of the phase difference angle, extract the maximum and minimum values ​​of the phase difference angle of the generator over the most recent 10 seconds, set the upper limit of the display range of the time change of the phase difference angle of the generator to 1.2 times the maximum value, and the lower limit to 0.8 times the minimum value, and use the median between the upper and lower limits as the central axis to appropriately change the display range of the phase difference angle of the generator to be displayed on the phase difference angle trend display unit 400. The display function may also be configured to superimpose the most recent time change in the phase difference angle and the time change in the phase difference angle from a predetermined time ago on the display device 15. For example, the display function may be configured to superimpose the most recent time change in the phase difference angle over the last 10 seconds on the time change in the phase difference angle from one minute or two minutes ago, or 30 minutes or one hour ago, on the display device 15. In this case, it is preferable to display the most recent time change in the phase difference angle in a darker color than the past time change in the phase difference angle. This allows the user to intuitively understand the most recent change in the phase difference angle of the generators by comparing it with the past changes in the phase difference angle. Furthermore, the display function may also be configured to display the time change in the bus voltage or the generator output (active power P and reactive power Q) on the phase difference angle transition display unit 400 in addition to or instead of the time change in the phase difference angle of each generator.

[0033] The stability display unit 500 displays a power phase difference angle curve (a chart showing generated power and phase difference angle), which is used as a stability indicator for the generator. The power phase difference angle curve is a curve (calculated value) calculated by the stability calculation function from the current configuration and state of the power system, and is calculated based on electrical theory, taking into account electrical changes such as increases and decreases in power generation and demand from renewable energy sources and transmission line outages (for example, it is calculated using known methods such as electrical circuit calculations using a reduced model or voltage flow calculations). The display function outputs the power phase difference angle curve calculated by the stability calculation function to the display device 15, thereby allowing the power phase difference angle curve to be displayed on the display device 15.

[0034] FIG. 9 is a diagram for explaining the stability display unit 500 according to this embodiment, and shows an example of the stability display unit 500. FIG. 10 is a partially enlarged view showing an example of the stability display unit 500 according to this embodiment. The display function displays a steady-state stability index indicating the steady-state stability of each generator, as shown in FIGS. 9 and 10. Specifically, the display function superimposes on a graph, as the steady-state stability index, a power phase difference angle curve C1 in the current configuration of the power system calculated by the stability calculation function and a power phase difference angle curve C2 when the configuration of the target power system is changed, and displays the graph on the display of the display device 15. Furthermore, the display function displays, as the steady-state stability index, the current active power value P of the generator G, as shown in FIG. 9. G and phase difference angle θ G 9(B), 9(C) and 10(A) to 10(C), the display function plots the active power value P1 of the generator G at a predetermined time before (for example, one minute before) as a steady-state stability index. G and phase difference angle θ G Plot P2 shows the active power value P of an even earlier time (for example, 2 minutes ago). G and phase difference angle θ G A plot P3 showing the current active power value P is also plotted on the graph and displayed on the display of the display device 15. In this case, the display function may be, for example, G and phase difference angle θ GThe plot P1 showing the active power value P G and phase difference angle θ G The plot P2 showing the active power value P at an earlier time is displayed in a lighter color than P1. G and phase difference angle θ G The plot P3, which indicates the active power value P of the generator and the phase difference angle θ, can be displayed in a lighter color than the colors P1 and P2. This allows the user to intuitively understand how the active power value P of the generator and the phase difference angle θ change over time.

[0035] 9(A) to 9(C), the stability display unit 500 allows a threshold value setting area A1 to set a threshold value for notifying the user when the phase difference angle of the generator becomes equal to or greater than a predetermined value. Specifically, in the threshold value setting area A1, the user can set a first threshold value δ1 indicating the phase difference angle of the generator at which an alarm should be issued in the current power system configuration via the input device 17. Note that the first threshold value δ1 may be configured to be automatically set in advance based on a pre-expected event, and in this case, the user may also be configured to be able to change the preset first threshold value δ1 as appropriate. In addition, in this embodiment, once the first threshold value δ1 is set, the display function automatically sets a second threshold value δ2 based on the set first threshold value δ1. Specifically, the display function first displays the active power value P at the first threshold value δ1 on the power phase difference angle curve C2 when the power system configuration is changed. δ1 Then, the display function calculates the calculated active power value P on the power phase difference angle curve C1 in the current power system configuration. δ1 is calculated as the second threshold value δ2 and set, and the stability display unit 500 displays the second threshold value δ2.

[0036] When the phase difference angle of the generator exceeds the first threshold value δ1 or the second threshold value δ2, the display function superimposes and displays an alarm area A2 colored in a highlighting color, such as red, on the stability display unit 500 as shown in FIGS. 9(B), (C) and 10(B), (C). For example, in the examples shown in FIGS. 9(A) and 10(A), the phase difference angle of the generator in the current power system configuration does not exceed the first threshold value δ1 or the second threshold value δ2, so the display function does not display the alarm area A2. In contrast, in the examples shown in FIGS. 9(B) and 10(B), the phase difference angle of the generator in the current power system configuration exceeds the second threshold value δ2. Furthermore, in the examples shown in FIGS. 9(C) and 10(C), the phase difference angle of the generator in the current power system configuration exceeds the second threshold value δ2 and the first threshold value δ1. In this case, as shown in FIGS. 9(B), (C) and 10(B), (C), the display function colors the area inside the power phase difference angle curve that is equal to or less than the current phase difference angle θ of the generator as a warning area A2 in red or other colors. This allows the user to intuitively understand that the generator phase difference angle is large and the power system is unstable. Furthermore, in this embodiment, as shown in FIGS. 9(B) and 10(B), when the generator phase difference angle in the current power system configuration exceeds a second threshold value δ2, which is a threshold value for when the power system configuration is changed, the display function displays the warning area A2 but does not output an alarm. Instead, when the generator phase difference angle exceeds a first threshold value δ1, which is a threshold value for the current configuration, the display function outputs an alarm. This allows the user to be alerted when the second threshold value δ2 is exceeded and to take prompt action when the first threshold value δ1 is exceeded.

[0037] Furthermore, in this embodiment, the user can change the configuration of the power system diagram displayed on the system diagram display unit 300 by specifying each component of the power system diagram displayed on the display device 15 via the input device 17. When the configuration of the power system diagram is changed, the display device 15 calculates new changed power phase angle curves for each generator in the stability display unit 500 in accordance with the changed configuration of the power system diagram. When the new changed power phase angle curves are calculated, the display device 15 also calculates a new second threshold value δ2 based on the changed power phase angle curves. The display device 15 then displays the newly calculated second threshold value δ2 in the stability display unit 500. If the current phase angle of a generator is equal to or greater than the newly calculated second threshold value δ2, the display device 15 displays buttons such as "Alarm Information" and "Restore Display" in the basic information display unit 200 in red, displays the generator figure in the power system diagram displayed on the system diagram display unit 300 in red, and further displays a red alarm area A2 in the stability display unit 500. This allows the user to more clearly understand how the steady-state stability of each generator will change when the configuration of the power system is changed, by linking the configuration of the power system with the steady-state stability of each generator, etc.

[0038] Furthermore, in this embodiment, the stability calculation function calculates the active power value P and phase difference angle θ of each generator at regular time intervals (for example, every few seconds), and the display function displays a plot P1 indicating the latest active power value P and phase difference angle θ calculated by the stability calculation function on the stability display unit 500. In this case, the display function displays the active power value P and phase difference angle θ at a time a predetermined time before the calculation time of the newly calculated active power value P and phase difference angle θ as plots P2 and P3 on the stability display unit 500. That is, the display function displays a plot P1 indicating the latest active power value P and phase difference angle θ on the stability display unit 500, and also displays, for example, an active power value P and phase difference angle θ calculated one minute before the calculation time at which the latest active power value P and phase difference angle θ were calculated as a new plot P2 on the stability display unit 500, and displays an active power value P and phase difference angle θ calculated two minutes before the calculation time at which the latest active power value P and phase difference angle θ were calculated as a new plot P3 on the stability display unit 500.

[0039] In this embodiment, the stability calculation function repeatedly calculates the active power value P and the phase difference angle θ every few seconds, but as shown in Figures 9 and 10, the display function extracts and plots only the active power value P and the phase difference angle θ from the repeatedly calculated active power value P and the phase difference angle θ a predetermined time ago, such as one minute and two minutes before the calculation time of the most recent active power value P and the phase difference angle θ. This is because plotting the most recent active power value P and the phase difference angle θ (for example, if the active power value P and the phase difference angle θ are calculated every two seconds, the most recent active power value P and the phase difference angle θ and the active power value P and the phase difference angle θ from two seconds and four seconds before) would reduce the change in the phase difference angle of the generator, which could reduce the visibility of the change in the phase difference angle. Furthermore, in this embodiment, the stability calculation function calculates the power phase difference angle curve and steady-state stability limit of each generator at regular time intervals (for example, every 10 minutes), and the display function displays the latest power phase difference angle curve and steady-state stability limit calculated by the stability calculation function on the stability display unit 500. This allows the user to grasp the ever-changing state of the power system in real time.

[0040] The display function can draw a power phase difference angle curve as follows to display a smooth power phase difference angle curve. That is, when there is a change in the configuration of the power grid, the display function divides the generator output from zero to the rated output value by a fixed number (for example, 10 divisions), and if the phase difference angle when output at the maximum division value (rated output value) exceeds a preset value (for example, 90°), the display function again divides the output by a fixed number (for example, 10 divisions) up to the division value just before the maximum value (the ninth division value), and draws the power phase difference angle curve when there is a change in the configuration of the power grid. When the phase difference angle still exceeds the preset value even at the division value just before the maximum value, the display function repeats the above division. By drawing the power phase difference angle curve in this way, a smooth power phase difference angle curve can be drawn.

[0041] In addition, when the configuration of the power system is changed, such as when some of the transmission lines or transformers that make up the power system are stopped, the display function can be configured to determine whether or not to issue an alarm using both a threshold value when demand is changed based on publicly known forecasts, and a threshold value when the configuration of the power system is restored to its original state.

[0042] As described above, in this embodiment, the display of the display device 15 displays the management screen 100 on which the basic information display section 200, the system diagram display section 300, the phase difference angle transition display section 400, and the stability display section 500 can be viewed on one screen.

[0043] As described above, in the power system management device 10 according to this embodiment, the power system diagram of the power system and the steady-state stability of the generators that make up the power system are displayed on a single screen on the display of the display device 15, allowing the manager / operator of the power system to grasp the steady-state stability of the generators that make up the power system together with the power system diagram. Furthermore, in this embodiment, in addition to the power system diagram of the power system and the steady-state stability of the generators, the time change in the phase difference angle of the generators that make up the power system and / or the measurement time of the phase difference angle of the generators that make up the power system (the update time of the phase difference angle of the generator) are displayed on a single screen, allowing the user to grasp the time change in the phase difference angle of the generators that make up the power system and the measurement time of the phase difference angle of the generators that make up the power system in a unified manner, allowing the user to grasp the state of the power system more intuitively and clearly.

[0044] Furthermore, in the power system management device 10 according to this embodiment, when the current phase difference angle of the generator exceeds the first threshold value δ1 or the second threshold value δ2, the stability display unit 500 displays an area inside the power phase difference angle curve that is equal to or smaller than the phase difference angle θ of the generator as an alarm area A2, highlighted in a color such as red, thereby enabling the user to intuitively understand that the phase difference angle of the generator is increasing and the steady-state stability is approaching an unstable area. Furthermore, in this embodiment, the alarm area A2, which indicates that the phase difference angle of the generator has exceeded the first threshold value δ1 or the second threshold value δ2, is visually visualized as an area inside the locus of sin θ using the power phase difference angle curve. As the phase difference angle of the generator increases beyond the first threshold value δ1 or the second threshold value δ2, the area of ​​the alarm area A2 increases exponentially, thereby effectively stimulating the user's sense of crisis.

[0045] Furthermore, in the power system management device 10 according to this embodiment, the user can change the configuration of the power system diagram displayed on the system diagram display unit 300 by specifying each component of the power system diagram displayed on the display device 15 via the input device 17. When the configuration of the power system diagram is changed, the display device 15 displays the steady-state stability of each generator in accordance with the changed configuration of the power system diagram in the stability display unit 500. When the configuration of the power system diagram displayed on the system diagram display unit 300 is changed, a new power phase difference angle curve for the changed configuration is calculated, and a new second threshold value δ2 is calculated based on the newly calculated power phase difference angle curve for the changed configuration. The display device 15 then displays the newly calculated second threshold value δ2 in the stability display unit 500. If the current phase difference angle of a generator is equal to or greater than the newly calculated second threshold value δ2, the display device 15 displays the generator's figure in the power system diagram displayed on the system diagram display unit 300 in red, and further displays a red warning area A2 in the stability display unit 500. This allows the user to compare the state before and after a change in the configuration of the power system, linking the configuration of the power system and the steady-state stability of each generator, thereby allowing the user to more clearly understand how the steady-state stability of each generator changes due to a change in the configuration of the power system.

[0046] Although the preferred embodiments of the present invention have been described above, the technical scope of the present invention is not limited to the above-described embodiments. Various modifications and improvements can be made to the above-described embodiments, and such modifications and improvements are also included in the technical scope of the present invention.

[0047] For example, in the above-described embodiment, the configuration of the management screen 100 shown in Figures 4 and 5 has been described as an example, but for example, a configuration may be adopted in which the positions of the basic information display section 200, the system diagram display section 300, the phase difference angle transition display section 400, and the stability display section 500 can be appropriately changed by the user operating the input device 17, as shown in Figures 11 to 14. Furthermore, the present invention is not limited to the above screen configuration as long as at least the system diagram display section 300 and the stability display section 500 can be displayed on a single screen, and for example, a configuration in which only the basic information display section 200, the system diagram display section 300, and the stability display section 500 are displayed by the user operating the input device 17, as shown in Figures 12 and 13. 11 illustrates a configuration in which the steady-state stability indexes of four generators are displayed on the stability display unit 500, similar to the example illustrated in FIG. 4. However, for example, the user can operate the input device 17 to enlarge and display only the steady-state stability index of one generator, or to display the steady-state stability indexes of one to three, or five or more generators. Note that FIG. 12 illustrates a configuration in which the steady-state stability indexes of five generators are displayed, while FIGS. 13 and 14 illustrate a configuration in which the steady-state stability indexes of two generators are displayed. In addition, the display function can be configured to display the steady-state stability indexes of all generators displayed on the system diagram display unit 300 on the stability display unit 500, or can be configured to display only the steady-state stability index of a generator specified by the user on the system diagram display unit 300 via the input device 17 on the stability display unit 500.

[0048] Furthermore, in the above-described embodiment, the management screen 100 is configured to display the basic information display section 200, the system diagram display section 300, the phase difference angle transition display section 400, and the stability display section 500, but the present invention is not limited to this configuration, and for example, the management screen 100 may also be configured to display a display section that indicates signs of oscillatory behavior in the power system. It is known that signs of oscillatory behavior appear as a characteristic of the power system, and for example, such signs (or unknown signs) may be extracted, and statistical processing such as cluster classification may be performed to detect the signs, and an alert may be issued when the signs are detected, and data used to detect the signs (such as the phase difference angle and voltage fluctuations) may be displayed on the management screen 100. For example, the power system management device 10 uses its stability calculation function to statistically process data such as generator phase angle and voltage fluctuations over periods such as one hour, one day, one month, or one year to calculate deviation values. When the deviation between the most recent data and the calculated deviation value exceeds a predetermined threshold, the display function can display the generator phase angle and voltage fluctuations as indicators of oscillatory behavior on the management screen 100. The detection of these indicators may be performed using functions or artificial intelligence (AI). The data displayed on the management screen 100 can be configured appropriately depending on the purpose. For example, the management screen 100 may display either or both of the generator phase angle and voltage fluctuations, or may prioritize multiple items for display, or may prioritize items with the greatest changes.

[0049] Furthermore, in the above-described embodiment, when the phase difference angle θ of the generator becomes equal to or greater than the preset thresholds δ1 and δ2, buttons such as "Alarm Information" and "Return Display" displayed on the basic information display unit 200 are displayed in red, the generator figure in the power system diagram displayed on the system diagram display unit 300 is displayed in red, and a red alarm area A2 is displayed on the stability display unit 500. However, the present invention is not limited to this configuration. For example, when the phase difference angle θ of the generator becomes equal to or greater than the steady-state stability margin of the generator, buttons such as "Alarm Information" and "Return Display" displayed on the basic information display unit 200 may be displayed in red, the generator figure in the power system diagram displayed on the system diagram display unit 300 may be displayed in red, and a red alarm area A2 may be displayed on the stability display unit 500. The steady-state stability margin can be calculated by multiplying the steady-state stability limit by a predetermined margin coefficient. The margin coefficient is a margin for notifying the power system manager / operator and urging them to take action when the generator phase difference angle θ approaches the generator's steady-state stability limit, even if it has not reached the steady-state stability limit of the power system, and the margin coefficient is set to a number greater than 0 and less than 1, such as 0.9. For example, if the steady-state stability limit is 80° and the margin coefficient is 0.9, the steady-state stability margin can be calculated as 80 × 0.9 = 72°. [Explanation of symbols]

[0050] 10…Power system management device 11...Communication equipment 12...Arithmetic device 13...Storage device 14...Database 15...Display device 100…Management screen 200…Basic information display section 300...System diagram display section 400... Phase difference angle transition display section 500...Stability display section 16...Alarm device 17...Input device

Claims

1. a stability calculation means for calculating a steady-state stability of a power system including at least one generator; a display means for displaying on a display device a management screen having a system diagram display unit for displaying a power system diagram showing the configuration of the power system and a stability display unit for displaying the steady-state stability of the generator; The display means causes the display device to display the system diagram display section and the stability display section on a single screen.

2. the stability calculation means calculates a steady-state stability index in a configuration of the power system and a steady-state stability index when the configuration of the power system is changed; 2. The power system management device according to claim 1, wherein the display means draws and superimposes on the stability display unit a display showing the steady-state stability index for the configuration of the power system and a display showing the steady-state stability index when the configuration of the power system is changed.

3. 3. The power system management device according to claim 2, wherein the stability calculation means calculates the steady-state stability index in a configuration of a power system further including a renewable energy power source, and the steady-state stability index when the configuration of the power system is changed.

4. 4. The power system management device according to claim 3, wherein the stability calculation means calculates, as the steady-state stability index when the configuration of the power system is changed, a steady-state stability index when the renewable energy power source is added to a configuration of the power system.

5. the stability calculation means calculates, as the steady-state stability index, a power phase difference angle curve that indicates a relationship between a power value of a predetermined generator in the power system and a phase difference angle; 3. The power system management device according to claim 2, wherein the display means plots, as the steady-state stability index, a power phase difference angle curve for the configuration of the power system and a power phase difference angle curve when the configuration of the power system is changed, and displays the plots in a superimposed manner.

6. the stability calculation means further calculates, as the steady-state stability index, a power value and a phase difference angle of the predetermined generator, and a steady-state stability limit which is a peak value of the power phase difference angle curve; 6. The power system management device according to claim 5, wherein the display means further plots and superimposes, as the steady-state stability indicators, an indication showing the power value and phase difference angle of the predetermined generator, an indication showing a steady-state stability limit in a configuration of the power system, and an indication showing a steady-state stability limit when the configuration of the power system is changed.

7. further comprising an acquisition means for acquiring output values ​​and output time information from each component of the power system; 7. The power system management device according to claim 1, wherein the stability calculation means calculates the steady-state stability based on the output values ​​output at the same time.

8. a stability calculation step of calculating a steady-state stability of a power system including at least one generator; a display step of displaying on a display device a management screen having a system diagram display unit that displays a power system diagram showing a configuration of the power system and a stability display unit that displays a steady-state stability of the generator, In the display step, the system diagram display section and the stability display section are displayed on a single screen.

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