Power system management device and power system management method

Abstract

To provide an electric power system management device and an electric power system management method that can appropriately monitor and operate an electric power system.SOLUTION: An electric power system management device has: acquisition means 12 that acquires output values from components connected to an electric power system; stability calculation means 12 that, based on the output values from the components acquired by the acquisition means 12, calculates a static stability index indicating the static stability of the electric power system; and display means 12 that displays the static stability index calculated by the stability calculation means 12. The stability calculation means 12 calculates a static stability index in the present configuration of the electric power system and a static stability index when the configuration of the electric power system is changed. The display means 12 draws displays indicating the static stability index in the present configuration of the electric power system and display indicating the static stability index when the configuration of the electric power system is changed, and displays them in a superimposed state.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Synchronous generators, such as those found in thermal, nuclear, and hydroelectric power plants, which have traditionally been the mainstream of power generation, rotate in synchronization with the frequency of the power grid. Even if a generator accelerates (or decelerates) for some reason, causing its phase angle to advance (or lag), a synchronizing force is known to act to return it to its original operating state. It is also known that the synchronizing force can transition the generator to a different, stable operating state in response to fluctuations in power supply and demand due to increases or decreases in the load (demand) in the power grid, or changes in the interconnection reactance due to a transmission line outage. Furthermore, synchronous generators possess inertia, which mitigates sudden changes during transient phenomena such as transmission line failures, and maintains the stability of the power grid through appropriate control by protective relays and other devices.

[0003] Renewable energy sources are a technology that can combat global warming and realize a decarbonized society, and various renewable energy power generation technologies are being developed, including small-scale hydroelectric power generation, solar power generation, wind power generation, geothermal power generation, and even tidal and wave power generation. Furthermore, the use of storage batteries is also progressing as a technology that contributes to adjusting power supply and demand. Many of these renewable energy sources and storage batteries are connected to the power grid via inverters (converters). Many renewable energy sources and storage batteries are connected to the power grid via inverters, and unless special control is applied, they do not have the above-mentioned synchronizing force or inertia force. Therefore, as the proportion of renewable energy sources in total power supply increases, there are concerns that the synchronizing force and inertia force of the entire grid will decrease, making it impossible to maintain the stability of the power grid. In particular, in relatively depopulated areas such as rural farming, mountain and fishing villages, renewable energy generation such as solar and wind power is increasing, while electricity demand is decreasing. Furthermore, because the power networks are weaker than in urban areas, the frequency of reverse power flow, in which electricity is sent from renewable energy sources up transmission lines to other areas, is increasing, and the amount of electricity in this reverse power flow is also increasing.

[0004] Therefore, there is a need to visualize, diagnose, and monitor the stability and transmission limits of the power system in real time, taking into account power demand, the amount of connected renewable energy sources, as well as power line accidents, equipment shutdowns for inspections, and changes to the power system configuration. This will enable the implementation of measures to ensure stability, such as changing operation plans and resupplying (switching) power sources, and ensure safe and secure operation of the power network. For example, Patent Document 1 discloses that the latest stability margin is displayed in an easy-to-visual illustration image using the terminal voltage, active power, reactive power, and system voltage of a synchronous machine, and that an alarm is issued if the stability margin becomes low. It also discloses that before changing the operating state of a synchronous machine or the circuit configuration of a power system, simulated data for when the configuration of the power system is changed is input, and the stability of the power system after the change is presented. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 5-316656 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in Patent Document 1, in order to present the stability when the configuration of the power system is changed, it is necessary to input simulated data after the configuration of the power system is changed, and it is not possible to compare in real time the steady-state stability limit when the configuration of the power system is changed with the steady-state stability limit of the power system in its current configuration, which poses a problem in that the administrator cannot quickly grasp the indicators for determining what kind of power system configuration should be changed, how to change the operation plan, and what measures to ensure stability should be taken, such as re-supplying power to the power source.

[0007] An object of the present invention is to provide a power system management device and a power system management method that are capable of appropriately monitoring and operating a power system. [Means for solving the problem]

[0008] The power system management device according to the present invention includes: an acquisition means for acquiring an output value of each component connected to the power system; and a steady-state stability index indicating the steady-state stability of the power system based on the output values ​​of the components acquired by the acquisition means. As the power phase difference angle curve and a display means for displaying the steady-state stability index calculated by the stability calculation means, wherein the stability calculation means Includes renewable energy sources The current configuration of the power system Power phase difference angle curve and, The relevant Power system current When the configuration is changed, Power phase difference angle curve and the display means calculates the current configuration of the power system. Power phase difference angle curve and a display showing the results when the configuration of the power system is changed. Power phase difference angle curve The display showing the When calculating the power phase difference angle curve in the current configuration of a power system including a renewable energy power source, and the power phase difference angle curve when the current configuration of the power system is changed, the stability calculation means calculates the phase difference angle of the renewable energy power source, and calculates the power phase difference angle curve using the calculated phase difference angle of the renewable energy power source. It further has an alarm means, and the acquisition means for acquiring the output values ​​of each component connected to the power system is composed of a means for measuring and transmitting the relationship between the generated power value of a specified generator in the power system and the phase difference angle based on a specified remote electric power station (equivalent to an infinite bus), and a means for measuring and transmitting the power generation amount and demand load status of renewable energy sources.The stability calculation means is characterized by superimposing predicted values ​​on current values ​​on indicators for the administrator to take measures to ensure stability using a single screen display or integrated visualized information, and the alarm means can issue an alarm when the steady-state stability is below a specified value. The stability calculation means calculates a power phase difference angle curve when the renewable energy power source is added to the current configuration of the power system, as a power phase difference angle curve when the current configuration of the power system is changed. The power system stability calculation means further includes an acquisition means for acquiring an output value of a component specified by a user, and the stability calculation means calculates the power phase difference angle curve using the output value of the component acquired by the acquisition means as the power phase difference angle curve when the configuration of the power system is changed. The stability calculation means calculates the steady-state stability index in the current configuration of the power system and the steady-state stability index when the configuration of the power system is changed, and the display means draws and superimposes a display showing the steady-state stability index in the current 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-described power system management device, the stability calculation means calculates, as the steady-state stability index, a power phase difference angle curve indicating the relationship between the generated power value (hereinafter referred to as power value) of a specified generator in the power system and a phase difference angle based on a specified remote electric power station (corresponding to an infinite bus), and the display means can be configured to draw, as the steady-state stability index, a power phase difference angle curve in the current configuration of the power system and a power phase difference angle curve when the configuration of the power system is changed, and display them superimposed on each other. Furthermore, the current power value and phase difference angle of the specified generator and the steady-state stability limit, which is the peak value of the power phase difference angle curve, are calculated as the steady-state stability index, and the display means can be configured to further draw and superimpose, as the steady-state stability index, a display showing the current power value and phase difference angle of the specified generator, a display showing the steady-state stability limit in the current configuration of the power system, and a display showing the steady-state stability limit if the configuration of the power system is changed. Regarding changes in the configuration of the power system, a steady-state stability index is calculated when the output value of some of the components connected to the power system is changed, and the display means can be configured to display the steady-state stability index when the output value of some of the components connected to the power system is changed, superimposed on the steady-state stability index in the current configuration of the power system, instead of or in addition to the steady-state stability index when the configuration of the power system is changed. For this reason, the power system may have a database in which system constants are stored in advance, and when output values ​​cannot be obtained from some components of the power system, the stability calculation means may be configured to estimate the output values ​​of the components from which output values ​​cannot be obtained based on the output values ​​of the components from which output values ​​can be obtained and the system constants stored in the database, and to calculate the steady-state stability index using the estimated output values. In the above-mentioned power system management device, the acquisition means can be configured to acquire the output value and output time information from each component of the power system, and the stability calculation means can be configured to calculate the steady-state stability index based on the output values ​​output at the same time. The power system management device can be configured to further include a notification means for determining the steady-state stability of the power system in its current configuration and the steady-state stability when the configuration of the power system is changed, and for issuing a notification when the steady-state stability of the power system in its current configuration or the steady-state stability when the configuration of the power system is changed is equal to or less than a predetermined value. In the above power system management device, the notifying means can be configured to determine the steady-state stability of the power system based on a steady-state stability margin, a synchronizing force margin, or an inertia constant of the power system based on an oscillation frequency. The power system management method according to the present invention acquires an output value of each component connected to the power system, and calculates a steady-state stability index (SSI) indicating the steady-state stability of the power system based on the acquired output values ​​of the components. As the power phase difference angle curve and displaying the calculated steady-state stability index, Includes renewable energy sources The current configuration of the power system Power phase difference angle curve and, The relevant Power system current When the configuration is changed, Power phase difference angle curve and calculate the current configuration of the power system. Power phase difference angle curve and when the configuration of the power system is changed, Power phase difference angle curve and are displayed superimposed on each other. When calculating the power phase angle curve in the current configuration of a power system including a renewable energy power source and the power phase angle curve when the current configuration of the power system is changed, the phase angle of the renewable energy power source is calculated, and the power phase angle curve is calculated using the calculated phase angle of the renewable energy power source. . In this way, the present invention is characterized by visually displaying a prediction of steady-state stability based on the effects of electrical changes such as increased power generation from renewable energy sources, decreased demand, and power line outages, as well as their impact on stability, geometrically superimposed on the current steady-state stability, based on measurement values ​​such as real-time measurements. [Effects of the Invention]

[0009] According to the present invention, the current steady-state stability of the power system and the steady-state stability when the configuration of the power system is changed are superimposed and visually displayed, thereby allowing the administrator to appropriately monitor and operate the power system. [Brief explanation of the drawings]

[0010] [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. 10 is a diagram illustrating another example of the configuration of the power system according to the present embodiment. [Figure 4] FIG. 10 is a diagram showing an example of a graph in which a power phase difference angle curve in the current configuration of the power system according to the present embodiment and a power phase difference angle curve when the configuration of the power system is changed are superimposed. [Figure 5] 10 is a flowchart illustrating a power management process according to the present embodiment. [Figure 6] 1 is a diagram illustrating a configuration of a power system according to a first embodiment. [Figure 7] 10 is a graph showing a part of a power phase difference angle curve C1 calculated using actual measured values ​​in the configuration of the power system of Example 1, and a part of a power phase difference angle curve C2 when the configuration of the power system is partially changed. [Figure 8] FIG. 10 is a diagram illustrating a configuration of a power system according to a second embodiment. [Figure 9] 10 is a graph showing changes in active power value and phase difference angle obtained using actual measured values ​​when a power transmission line is stopped in Example 2. [Figure 10] 10 is a graph showing changes in active power value and phase difference angle obtained using actual measured values ​​when the amount of power generated by the generator is increased in Example 2. [Figure 11] 10 is a graph showing changes in active power value and phase difference angle obtained using actual measured values ​​when a stopped power transmission line is restarted in Example 2. [Figure 12] 10 is a graph showing the effective power value and the phase difference angle when the power generation amount of an existing generator is increased in Example 3, by changing the components based on Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0011] An embodiment of the present invention will be described below with reference to the drawings. In the following, a power system to be managed will be referred to as a "target power system," and a power system management device that allows a manager to grasp the steady-state stability of the target power system will be described as an example. 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" or "renewable energy power sources." Furthermore, generators, renewable energy power sources, electric 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."

[0012] Fig. 1 is a configuration diagram of a power system management device 10 according to this embodiment. As shown in Fig. 1, the power system management device 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.

[0013] By executing a program stored in storage device 13, calculation device 12 has an acquisition function for acquiring system constants in the target power system and output values ​​of each component of the target power system, a stability calculation function for calculating a steady-state stability index of the power system based on the output values ​​of each component of the power system, a display function for displaying the steady-state stability index calculated by the stability calculation function, and a notification function for determining the steady-state stability of the power system and issuing a notification if the steady-state stability is low. Each function of calculation device 12 will be described below.

[0014] The acquisition function of the computing device 12 acquires system constants for the target power system. In this embodiment, system constants such as the impedance of power transmission lines and transformers, and generators and their internal constants are stored in advance in the database 14, and the acquisition function can acquire these system constants for the target 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 measurement device connected to the target power system, and the output values ​​measured by the measurement 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 can acquire GPS information including output time information from each measurement device connected to the target power system in addition to the output values ​​of each component of the power system, thereby acquiring information on the time when each component output a value.

[0015] FIG. 2 is a diagram showing an example of the configuration of a target power system according to this embodiment. In the target 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, from the database 14, the complex impedance r1+jx1 of the transmission line L1 and the complex impedance r2+jx2 of the transmission line L2 as system constants of the target power system. 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 , the voltage value V of the renewable energy power 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 target power grid.

[0016] The stability calculation function of the arithmetic device 12 calculates a steady-state stability index of the target power system. Specifically, the stability calculation function first calculates an active power value P of the target generator based on a voltage value V and a current value I of the target generator. For example, in the example shown in FIG. 2, if the target generator is generator G, the stability calculation function calculates a steady-state stability index of the target power system based on a voltage value V and a current value I of 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 measured value θ from the difference with the measured value θ standard of the specified distant electric power station (electric power station equivalent to an infinite bus). G can be obtained.

[0017] The stability calculation function also calculates a steady-state stability index that indicates the steady-state stability of the target power system using the output values ​​of each component connected to the target power system. Specifically, the stability calculation function first calculates, as the steady-state stability index, a power phase difference angle curve that indicates the relationship between the generated power value P of the target 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 that is the peak value of the power phase difference angle curve.

[0018] For example, in the example shown in FIG. 2, if the target generator is generator G, 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 target 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 GTheoretically, 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 θ P 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

[0019] 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 active power value P G The phase difference angle at which the peak is reached is calculated as the steady-state stability limit.

[0020] 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 target power system is changed. Here, FIG. 3 is a diagram showing an example of a changed configuration of the target power system. FIG. 3(A) shows a configuration in which a renewable energy power source P is removed from the current configuration of the target 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 target 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 target 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 target power system is changed, as shown in FIGS. 3(A) to 3(D).

[0021] The power phase angle curves for the configurations shown in Figures 3(A) to 3(D) can be calculated using known methods, and therefore will not be described here. Furthermore, when the configuration of the target power system is changed, the resulting configuration is not particularly limited. For example, the administrator may input a command in advance via input devices 17, such as a keyboard or mouse, or the stability calculation function may automatically determine the configuration based on certain rules. Furthermore, for output values ​​of components that cannot be measured in the target power system, the measured output values ​​of other components or known transmission line impedance can be used to correct for the influence of power flows caused by renewable energy sources, etc. 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 a measurement device. However, the power phase angle curve can also be calculated using measurement values ​​measured at different sampling times, such as telemeters for 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 administrator. 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.

[0022] As shown in Fig. 4, the display function of the arithmetic unit 12 plots the power phase difference angle curve for the current configuration of the target power system calculated by the stability calculation function and the power phase difference angle curve for when the configuration of the target power system is changed, superimposing them on a graph, and displays them on the display of the display device 15. In addition, the display function also plots the active power value P G and phase difference angle θ GA display showing this (for example, point p in FIG. 4) is drawn on the graph and displayed on the display of display device 15. Note that FIG. 4 is a diagram showing an example of a graph in which the power phase difference angle curve in the current configuration of the target power system according to this embodiment is superimposed on the power phase difference angle curve when the configuration of the target power system is changed.

[0023] For example, in the example shown in Figure 4, Figure 4(C) shows the power phase difference angle curve for the current configuration of the target power system shown in Figure 2. Also, Figure 4(A) shows the power phase difference angle curve when renewable energy power source P is removed from the current configuration of the target power system (or when power source P is stopped), as shown in Figure 3(A). Figure 4(B) shows the power phase difference angle curve when renewable energy power source P is removed from the current configuration of the target power system and load B is added, as shown in Figure 3(D). Also, Figure 4(D) shows the power phase difference angle curve when renewable energy power source P2 is added to the current configuration of the target power system, as shown in Figure 3(B). Figure 4(E) shows the power phase difference angle curve when the output power of renewable energy power source P is higher than that of Figure 4(D) in the current configuration of the target power system shown in Figure 2. The configuration shown in Figure 3(C) is a combination of the configuration in Figure 3(B) in which renewable energy power sources P1 and P2 are connected and the configuration in Figure 3(D) in which load B is connected, and can be calculated according to the respective parameters.

[0024] As shown in Fig. 4, the display function not only displays the power phase difference angle curve in the current configuration of the target power system (for example, the power phase difference angle curve in Fig. 4(C)), but also displays the power phase difference angle curves in the case where the configuration of part of the target power system is changed (for example, the power phase difference angle curves in Fig. 4(A), (B), (D), and (E)), which are superimposed on a graph and displayed on the display of the display device 15. Furthermore, as shown in Fig. 4, the display function displays the active power value P G and phase difference angle θ G A point p indicating the above is displayed on the power phase difference angle curve of the current configuration of the target power system (for example, the power phase difference angle curve in FIG. 4(C)).

[0025] As described above, in this embodiment, the display function displays the power phase difference angle curve (C) in the current configuration of the target power system and the power phase difference angle curve when the configuration of the target power system is changed, superimposed on each other, and also displays the generated power measurement value P based on the real-time measurement value. G and the measured value θ G By plotting on the power phase difference angle curve (C) or near the power phase difference angle curve (C) due to the influence of measurement errors, the administrator can visually grasp, with the current point as the base, how the steady-state stability of the power system will change depending on how the configuration of the target power system is changed. For example, in the example shown in Figure 4, the stability calculation function calculates the steady-state stability limit θ of the power phase difference angle curve (C) in the current configuration of the target power system. C is calculated as 85.2°. Also, the current active power value P of the target generator, generator G, is G is 20 [pu] shown as P0 in FIG. 4, the current phase difference angle θ G is approximately 54°, as shown by θ1. Therefore, the manager should C Comparing the 85.2° of the phase difference angle θ1 of generator G with the phase difference angle θ of generator G, G is the steady-state stability limit θ C It can be seen that the steady-state stability of the target power system in its current configuration is high.

[0026] In this embodiment, when the administrator uses the input device 17 to move the cursor displayed on the display of the display device 15 to the power phase difference angle curve (C) or point p also displayed on the display, the display function displays the configuration of the target power system indicated by the power phase difference angle curve (C), the value of the steady-state stability limit θc, and the current power value P of the generator G indicated by point p. G or phase difference angle θ G This allows the administrator to view the power system configuration shown by the power phase angle curve (C), the value of the steady-state stability limit θc, and the active power value P of the generator G shown by point p. G or phase difference angle θ GIn this embodiment, the display function can change the color or type of line (for example, a wavy line, a thick line, etc.) for each power phase difference angle curve displayed on the display device 15, making it easier for the administrator to distinguish between the power phase difference angle curves.

[0027] In the example shown in FIG. 4, when the administrator uses the input device 17 to move the cursor displayed on the display to the power phase difference angle curve shown in FIG. 4(A), the display function displays the configuration of the target power system that results in the power phase difference angle curve shown in FIG. 4(A) (the configuration shown in FIG. 3(A)) and the steady-state stability limit θ A The numerical value of can be displayed on the display. This allows the administrator to understand that when the current configuration of the target power system shown in Figure 2 is changed to the configuration shown in Figure 3(A) by removing the renewable energy power source P, the power phase difference angle curve will change from the curve shown in Figure 4(C) to the curve shown in Figure 4(A). In addition, in the power phase difference angle curve shown in Figure 4(A), the steady-state stability limit θ A is 90°, and the phase difference angle θ0 for the current active power value P0 (20 [pu]) of generator G is approximately 38°. Therefore, the administrator can understand that if the current configuration of the power system is changed to the configuration shown in Figure 3(A), the steady-state stability will be higher (stability will increase) than the current configuration of the target power system.

[0028] Similarly, in the example shown in Fig. 4, when the administrator places the cursor displayed on the display on the power phase difference angle curve shown in Fig. 4(D), the display function displays the configuration of the target power system (the configuration shown in Fig. 3(B)) that results in the power phase difference angle curve shown in Fig. 4(D) and the steady-state stability limit θ C The value of can be displayed on the display. This allows the administrator to understand that when the renewable energy power source P2 is added to the current configuration of the target power system shown in Figure 2 and changed to the configuration shown in Figure 3(B), the power phase difference angle curve will change from the curve shown in Figure 4(C) to the curve shown in Figure 4(D). In addition, in the power phase difference angle curve shown in Figure 4(D), the steady-state stability limit θ Dis 84.5°, and the phase difference angle θ2 for the current active power value P0 (20 [pu]) of generator G is approximately 78°. Therefore, the administrator can understand that if the current configuration of the power system is changed to the configuration shown in Figure 3(B), the steady-state stability will be lower than the current configuration of the target power system, and that although the steady-state stability is within an acceptable range, it will approach the limit value.

[0029] Furthermore, in the example shown in Fig. 4, when the administrator places the cursor displayed on the display on the power phase difference angle curve shown in Fig. 4(E), the display function displays the configuration of the target power system that results in the power phase difference angle curve shown in Fig. 4(E) (the configuration shown in Fig. 2 with the output value of the renewable energy power source P increased) and the steady-state stability limit θ E The value of is displayed on the display. This allows the administrator to understand that if the output of the renewable energy power source P is increased in the current configuration of the target power system shown in Figure 2, the power phase difference angle curve will change from the curve shown in Figure 4(C) to the curve shown in Figure 4(E). Furthermore, in the power phase difference angle curve shown in Figure 4(E), the steady-state stability limit θ E Since the following phase difference angle cannot be obtained, the administrator can understand that if the output value of the renewable energy power source P is increased in the current configuration of the power system, the steady-state stability will become unstable (exceed the steady-state stability limit) and will exceed the allowable range.

[0030] Next, the notification function of the computing device 12 will be described. The notification function determines the steady-state stability of the target power system and issues a warning to the administrator if the steady-state stability is equal to or lower than a predetermined value. Specifically, the notification function first calculates the synchronizing force F of the target power system by measuring the power value P and phase difference angle θ of the target generator over time. More specifically, the notification function can calculate the synchronizing force F using the formula F=dP / dθ based on the time-series data of the power value P and phase difference angle θ of the target generator. Note that the synchronizing force F varies depending on the influence of small disturbances during operation of the target power system (e.g., tap changes of an interconnection transformer, switching on and off of a transmission line, system changes, system faults including those at distant locations, etc.). In this embodiment, the database 14 stores time-series data of the power value P and phase difference angle θ of the target generator, and the notification function can reference the database 14 to obtain the time-series data of the power value P and phase difference angle θ of the target generator.

[0031] The notification function determines the steady-state stability of the target power system by determining the following conditions: Specifically, if either of the following conditions (1) or (2) is met, the notification function determines that the steady-state stability of the target power system is low, and causes the display device 15 or the notification device 16 to issue an alarm.

[0032] (1) The current phase difference angle θ of the target generator > steady-state stability margin M1 (steady-state stability margin M1 = steady-state stability limit in the current configuration of the target power system × margin coefficient C1) (2) Synchronizing power F of the target power system < Synchronizing power margin M2 (Synchronizing power margin M2 = Synchronizing power F at the steady-state stability limit + margin coefficient C2) In the above, the synchronizing force F at the steady-state stability limit is "0." The margin coefficient is a margin for notifying the administrator when the phase difference angle θ of the target generator approaches the steady-state stability limit of the target power system, even if it has not reached the steady-state stability limit of the target power system. The margin coefficient C1 is set to a number greater than 0 and less than 1, such as 0.9, and the margin coefficient C2 is set to a number greater than 0, such as 0.2.

[0033] In addition, the notification function can also be configured to predict future output values ​​of generators, renewable energy sources, power stations, loads, etc., and determine the steady-state stability of the target power system based on the predicted output values, as shown in (3) and (4) below. (3) Phase difference angle θ of the target generator after 1 hour > Steady-state stability margin M1 after 1 hour (Steady-state stability margin M1 after 1 hour = Steady-state stability limit of the target power system configuration after 1 hour × margin coefficient C1) (4) Phase difference angle θ of the target generator after n hours > Steady-state stability margin M1 after n hours (Steady-state stability margin M1 after n hours = Steady-state stability limit of the target power system configuration after n hours × margin coefficient C1) In this case, past performance data of each component of the target power system and performance data of the output values ​​of each component are stored in database 14, and the notification function can use this performance data to calculate the phase difference angle θ of the target generator one hour or n hours later and the steady-state stability limit of the target power system.

[0034] In addition, the notification function may be configured to determine that the steady-state stability of the target power system is low and issue an alarm on the display device 15 or the notification device 16 when any of the following conditions (1') to (4') are met, instead of the above conditions (1) to (4). (1') Steady-state stability margin M1' (Steady-state stability margin M1' = Steady-state stability limit in the current configuration of the target power system - Current phase difference angle θ of the target generator) < Predetermined value (2') Synchronization force margin M2' (synchronization force margin M2' = synchronization force F of the target power system - synchronization force F at the steady-state stability limit) < predetermined value (3') Steady-state stability margin M1' after 1 hour (Steady-state stability margin M1' after 1 hour = Steady-state stability limit of the target power system in the configuration after 1 hour - Current phase difference angle θ of the target generator) < Predetermined value (4') Steady-state stability margin M1' after n hours (Steady-state stability margin M1' after n hours = Steady-state stability limit of the target power system in the configuration after n hours - Current phase difference angle θ of the target generator) < Predetermined value

[0035] Furthermore, the notification function can be configured to determine the steady-state stability of the target power system as shown below. That is, the notification function extracts the oscillation frequency f based on the time change of the phase difference angle θ of the target generator, and calculates the inertia constant of the target power system from the relationship between this oscillation frequency f and the synchronizing force F. The notification function can then be configured to determine the steady-state stability of the target power system by comparing the calculated inertia constant of the target power system with the known inertia constants of each generator. The oscillation frequency f is calculated at intervals of, for example, 0.1 to 10 seconds.

[0036] If the notification function determines that the steady-state stability of the target power system is low, it causes the display device 15 or the notification device 16 to issue an alarm. For example, if the notification function determines that the steady-state stability of the current configuration of the target power system is low, it issues a relatively strong warning because there is a high need to change the current configuration of the target power system. For example, the notification function can cause the display device 15 to display an emphasized warning message and the notification device 16 to output an audible warning. Note that the notification function can also be configured to periodically determine the steady-state stability of the current configuration of the target power system, and to forcibly issue the above-mentioned notification if it determines that the steady-state stability is low.

[0037] Furthermore, when it is determined that changing the configuration of the target power system will lower the steady-state stability, the notification function can issue a relatively weak warning to prevent the change to the configuration of the target power system. For example, the notification function can be configured to display a predetermined warning message on display device 15. In this case, the notification function can be configured to display the warning message when the administrator operates input device 17 to align the cursor displayed on the display with the power phase difference angle curve when the configuration of the target power system is changed.

[0038] In this way, the notification function determines the steady-state stability of the target power system with a certain margin, allowing the administrator to take necessary measures before the steady-state stability of the target power system reaches the steady-state stability limit. In addition, the notification function determines the steady-state stability for each configuration of the target power system, allowing the administrator to understand how the steady-state stability will change depending on how the configuration of the target power system is changed.

[0039] Next, the power management process according to this embodiment will be described. Fig. 5 is a flowchart showing the power management process according to this embodiment. The power management process according to this embodiment is repeatedly executed at a predetermined interval by the arithmetic unit 12 of the power system management device 10.

[0040] 5, in step S101, the output values ​​of each component of the target power system are acquired by the acquisition function of the calculation device 12. Specifically, the acquisition function acquires the system constants of the target power system from the database 14, and also acquires output values ​​such as voltage values ​​and current values ​​of each component measured by a measurement device connected to the target power system.

[0041] In step S102, the stability calculation function of the arithmetic device 12 calculates the power value and phase difference angle of the target generator based on the output value of the target generator acquired in step S101. Then, in step S103, the stability calculation function calculates a power phase difference angle curve for the current configuration of the target power system based on the system constants and output values ​​of each component acquired in step S101 and the power value and phase difference angle of the target generator calculated in step S102.

[0042] In step S104, the stability calculation function calculates a power phase difference angle curve when the configuration of the target power system is changed based on the system constants and output values ​​of each component acquired in step S101, and the power value and phase difference angle of the target generator calculated in step S102. Note that the configuration of the target power system after the change can be appropriately specified by the administrator via input device 17, such as by changing the system or shutting down equipment.

[0043] In step S105, the display function causes the multiple power phase difference angle curves calculated in steps S103 and S104 to be superimposed and displayed on the display of the display device 15. In addition, in step S106, the display function causes point p indicating the power value and phase difference angle of the target generator calculated in step S102 to be superimposed on the power phase difference angle curve drawn in step S105 and displayed on the display device 15.

[0044] In step S107, the notification function determines the current steady-state stability of the target power system. For example, if the current phase difference angle of the target generator exceeds the steady-state stability margin M1 of the target power system's current configuration, the notification function can determine that the steady-state stability of the target power system's current configuration is low. The notification function can also refer to database 14 to calculate synchronizing force F based on time-series data of the target generator's power value P and phase difference angle θ, and determine that the steady-state stability of the target power system's current configuration is low if the synchronizing force F of the target power system is lower than the synchronizing force margin M2. If the notification function determines in step S108 that the steady-state stability of the target power system's current configuration is low, the process proceeds to step S109, where the notification function issues an alarm. In this case, because the current configuration of the target power system needs to be changed, the notification function displays a warning message in emphasis on display device 15 and also outputs an alarm sound from alarm device 16. If it is not determined in step S108 that the steady-state stability of the target power system in its current configuration is low, the process proceeds directly to step S110.

[0045] In step S110, the notification function determines the steady-state stability when the configuration of the target power system is changed. In particular, in step S110, the notification function predicts power generation and load conditions one hour and n hours from now based on past measurement data accumulated in database 14, and, taking into account the error rate of the prediction, determines the steady-state stability when the configuration of the target power system is changed due to equipment shutdowns, system configuration changes, etc. If the notification function determines in step S111 that the steady-state stability will be reduced when the configuration of the target power system is changed, the process proceeds to step S112, where the notification function issues an alarm. Note that, when an administrator places a cursor on a power phase angle curve when the configuration of the target power system is changed, the notification function determines the steady-state stability of the target power system configuration indicated by the cursor, and if it determines that the steady-state stability is low, displays a warning associated with the power phase angle curve.

[0046] After the processing up to step S112 has been performed, the process returns to step S101, and the above processing is repeated. In this manner, in this embodiment, the steady-state stability of the target power system in the current configuration and the steady-state stability when the configuration of the target power system is changed are determined based on the latest output values ​​of each component, thereby allowing the administrator to grasp, in real time, the steady-state stability of the current configuration and the steady-state stability when the current configuration is changed. [Example]

[0047] Example 1 Next, a first example of the power system management device 10 according to this embodiment will be described. In the first example, a steady-state stability index is calculated for a current configuration of an existing power system. Specifically, in the first example, a phase difference angle θ is calculated from an active power value P measured in the current configuration of the existing power system and a phase angle measured at the same sampling period. GUsing the actual measured values, a power phase difference angle curve in the current configuration and a power phase difference angle curve in the case where the components are changed are calculated and displayed on the display device 15. FIG. 6 is a diagram showing the configuration of a power system according to Example 1. Note that the power system of Example 1 is an actual power system, and as shown in FIG. 6, two generators G1 and G2, two renewable energy power sources P1 and P2, and two loads B1 and B2 are connected via power transmission lines L1 to L3 and a transformer L4. The power transmission line L3 is made up of power transmission lines L3a and L3b, and the transformer L4 is made up of transformers L4a and L4b.

[0048] In the power system shown in FIG. 6, output values ​​(hereinafter also referred to as actual measured values) such as the amount of power generated and the amount of demand are measured for 24 hours, and based on the measured actual measured values, a power phase difference angle curve C1 of the generator G1 in the configuration of the power system shown in FIG. 6 is calculated, and the active power value P G1 and phase difference angle θ G1 was calculated and plotted. Fig. 7 is a graph showing a part of the power phase difference angle curve C1 of the generator G1 in the power system configuration shown in Fig. 6, and a part of the power phase difference angle curve C2 of the generator G1 when the power system configuration shown in Fig. 6 is partially changed. In Fig. 7, R1 is the effective power value P of the generator G1 during the 24-hour period actually measured. G1 and phase difference angle θ G1 R2 indicates the area where the effective power value P G1 and phase difference angle θ G1 In the example shown in Fig. 7, the active power value P of the target generator was calculated, so in Fig. 7, the active power value P is displayed on a 1000 kVA basis (the same applies to Fig. 12 described later).

[0049] The direction and magnitude of the current (power flow) change, and the phase difference angle θ changes, depending on the power system configuration, the output of generators G1 and G2, the magnitude of demand from loads B1 and B2, and the correlation between the power generation output of renewable energy sources P1 and P2. In this example, a power phase difference angle curve C2 for generator G1 when a portion of the power system configuration is changed is also calculated and displayed superimposed on the graph shown in FIG. 7. Specifically, the power phase difference angle curve C2 when transmission line L3b and transformer L4b are stopped in the power system shown in FIG. 6 is calculated from various measured values, electrical constants, system constants, etc. in the power system shown in FIG. 6, and displayed superimposed on the graph shown in FIG. 7. When transmission line L3b and transformer L4b are stopped in the power system shown in FIG. 6, the transformer L4 and transmission line L3 change from a two-unit, two-circuit parallel configuration to a one-unit, single-circuit configuration. This approximately doubles the impedance in that section, and the impedance from generator G1 to the remote electric power station increases. In the power system shown in Figure 6, when the output of generator G1 is zero, the loads B1 and B2 form a power flow cross section in the direction of receiving power from the distant electric power station. Therefore, as shown in Figure 7, when the output of generator G1 is zero, the phase difference angle θ is lagging. As the output of generator G1 increases, the phase difference angle θ gradually shifts to leading. Furthermore, if the demand from loads B1 and B2 is greater than the total power generation, including renewable energy sources P1 and P2, and one transformer L4 and one transmission line L3 are shut down, the phase difference angle θ will shift more lagging than the phase difference angle in the current configuration. Conversely, if the demand from loads B1 and B2 is less than the total power generation, including renewable energy sources P1 and P2, and one transformer L4 and one transmission line L3 are shut down, the phase difference angle θ will shift more leading than the phase difference angle in the current configuration, approaching the steady-state stability limit. In the present Example 1, the demand amount of the loads B1 and B2 is greater than the amount of power generated including the renewable energy power sources P1 and P2. Therefore, by stopping the power transmission line L3b and the transformer L4b, the power phase difference angle curve C1 was calculated to shift in the lagging direction to the power phase difference angle curve C2, as shown in FIG. 7 .

[0050] In this way, in the first embodiment, the actual measured values ​​of the existing power system are used to calculate the power phase difference angle curve C1 in the current configuration of the power system, and the active power value P calculated from the measured values ​​for 24 hours this time in the region R1 on the power phase difference angle curve C1 is G1 and phase difference angle θ G1 It was also possible to calculate and display the power phase difference angle curve C2 in a configuration in which one transformer L4 and one transmission line L3 were stopped. In this way, it was found that the power system management device 10 according to this embodiment can be applied to an actual electrical system.

[0051] Example 2 In Example 2, a power phase difference angle curve was calculated when the configuration of the power system was changed from the current configuration, and then the configuration of the power system was actually changed. The active power value P and the phase difference angle θ were calculated based on the measured values ​​in the changed configuration, and it was verified whether the calculated active power value P and the phase difference angle θ were values ​​that matched the power phase difference angle curve in the changed configuration. Note that, since it is difficult to intentionally change an existing power system to a state with low steady-state stability, in Example 2, measurements were taken using a small generator and a simulated circuit of the power system using a method similar to that of a real system, and the measured results were obtained.

[0052] Fig. 8 is a diagram showing the configuration of the power system in Example 2. Figs. 9 and 11 show the effective power value P G and phase difference angle θ G 10 is a graph showing the change in the active power value P of the generator G when the output of the generator G is changed in the power system shown in FIG. G and phase difference angle θ G 9 to 11, a generator smaller than the target generator of Example 1 shown in FIG. 7 is used, and therefore in FIGS. 9 to 11, the active power value P is shown on a 1 kVA basis.

[0053] In the example shown in Fig. 9, the power phase difference angle curve of the generator G in the configuration of the power system shown in Fig. 8 is shown as C3, and the power phase difference angle curve of the generator G when the transmission line L5b is stopped in the power system of Example 2 is shown as C4. Also, in Fig. 9, the active power value P of the generator G calculated from the actual measured value before and after the transmission line L5b is stopped in the power system shown in Fig. 8 is G and phase difference angle θ G In the power system shown in FIG. 8, before the transmission line L5b is stopped, the active power value P G and phase difference angle θ G The value of the active power P of the generator G was shown as P1 on the power phase difference angle curve C3. G and phase difference angle θ G First, the power phase difference angle changes to P2 on the power phase difference angle curve C4, and the effective power value P G After that, the active power value P of the generator G decreased. G and phase difference angle θ G is the effective power value P along the power phase difference angle curve C4. G While increasing the phase difference angle θ G changes in the forward direction, passes through P3, and finally reaches the same effective power value P G This resulted in P4.

[0054] In the example shown in FIG. 10, the active power value P of the generator G is increased without changing the configuration of the power system. G and phase difference angle θ G 10 shows the change in the active power value P of the generator G before and after increasing the power generation amount of the generator G. In the example shown in FIG. 10, the power system shown in FIG. 8 is configured with the transmission line L5b stopped, and only the power generation amount of the generator G is increased. The power phase difference angle curve of the generator G in this configuration is shown as C5, and the power phase difference angle curve of the generator G when the transmission line L5b is restarted is shown as C6. In addition, in FIG. 10, the active power value P of the generator G before and after increasing the power generation amount of the generator G is shown as G and phase difference angle θ GAs shown in FIG. 10, the active power value P G and phase difference angle θ G Before the power output of generator G was increased, the active power value P of generator G was at P5 on the power phase difference angle curve C5, but after the power output of generator G was increased, it changed to P6 on the same power phase difference angle curve C5. In other words, when the power output of generator G was increased, it did not move to the power phase difference angle curve C6 when the configuration of the power system was changed, but moved along the power phase difference angle curve C5 in the current configuration. G increases, and the phase difference angle θ G has changed to a forward direction.

[0055] Furthermore, in the example shown in FIG. 11, when the power transmission line L5b is stopped in the power system shown in FIG. 8, the power transmission line L5b is restarted and the configuration of the power system is changed to that shown in FIG. 8, and the effective power value P G and phase difference angle θ G 11 shows the change in the active power value P of the generator G calculated from the actual measured values ​​before and after the restart of the transmission line L5b. In the example shown in FIG. 11, the power system shown in FIG. 8 is configured such that the transmission line L5b is stopped, and the power phase difference angle curve of the generator G in this configuration is shown as C7, and the power phase difference angle curve of the generator G when the transmission line L5b is restarted is shown as C8. In addition, in FIG. 11, the active power value P of the generator G calculated from the actual measured values ​​before and after the restart of the transmission line L5b G and phase difference angle θ G In the power system shown in FIG. 8, when the transmission line L5b is stopped, the active power value P G and phase difference angle θ G was P7 on the power phase difference angle curve C7. After that, when the power transmission line L5b was restarted and the power system configuration was changed to that shown in Figure 8, the active power value P G and phase difference angle θ G First, when the configuration is changed, the power phase difference angle changes to P8 on the power phase difference angle curve C8, and the phase difference angle θ G remains unchanged, and the effective power value P G Then, the active power value P of the generator G G and phase difference angle θ G is the effective power value P along the power phase difference angle curve C8.G As the phase difference angle θ G gradually becomes delayed, and finally reaches the same effective power value P G It changed to P10.

[0056] In this way, in the second embodiment, when the configuration of the power system is actually changed, the effective power value P G and phase difference angle θ G It was confirmed that the value actually changes on the power phase difference angle curve simulated based on the changed configuration. Also, when the power generation amount of generator G is changed without changing the configuration of the power system, the active power value P of generator G changes on the power phase difference curve in the current configuration. G and phase difference angle θ G It was thus confirmed that the power system management device 10 according to this embodiment can appropriately calculate the phase difference angle curve in the current configuration of the power system, the active power value P and the phase difference angle θ in the current configuration of the power system, and the phase difference angle curve when the configuration of the power system is changed.

[0057] Example 3 In Example 3, in the configuration of the power system shown in Figure 6, contrary to Example 1, when the demand of the loads B1 and B2 is smaller than the power generation amount including the renewable energy power sources P1 and P2, that is, when the renewable energy power sources exceed the demand, the active power value P and the phase difference angle θ when the configuration of the power system is changed are calculated based on the operating state of the actual system. Figure 12 is a graph showing the active power value P and the phase difference angle θ of the generator when the power generation amount of the generator is increased in an actual power system. Note that Figure 12 shows the active power value P when the power generation amount of the generator G1 is changed in an actual power system that has the same configuration as Figure 6 but is different from Example 1. G1 and phase difference angle θ G1 The transition of the active power value P when the power generation amount of the generator G1 is changed when one transmission line is stopped for inspection in the power system is shown as C9. G and phase difference angle θ GThe transitions C9 and C10 shown in FIG. 12 are obtained by increasing the amount of power generated by the generator G1 by a predetermined amount and changing the active power value P G and phase difference angle θ G was calculated and plotted.

[0058] As shown in C9 of FIG. 12, in the configuration of the power system shown in FIG. 6, when the power generation amount of the generator G1 is changed, the effective power value P G and phase difference angle θ G The trend of C9 is that as the amount of power generation increases, the active power value P G1 As the phase difference angle θ G It was confirmed that the curve gradually changes to the leading direction, showing the same change as the power phase difference angle curve. Also, as shown in C10 in Fig. 12, in a configuration where one transmission line is stopped, even when the power generation amount of generator G is increased, the active power value P G As the phase difference angle θ G It was confirmed that the curve gradually changes in the leading direction, showing the same change as the power phase difference angle curve. In the power system shown in Figure 12, the demand is smaller than the power generation, so when one transmission line is stopped, the same active power value P G However, compared to normal operation, the phase difference angle θ changes in the leading direction, and as a result, the effective power value P when one transmission line is stopped G and phase difference angle θ G The transition of C10 is the active power value P G and phase difference angle θ G The calculated trend was more advanced than C9.

[0059] As described above, Examples 1 to 3 show that the power system management device 10 according to this embodiment can obtain the power phase difference angle curve for the current power system configuration and the power phase difference angle curve for when the current power system configuration is changed as curves that match the actual measured values. From this, it was found that the power system management device 10 according to this embodiment can visualize the steady-state stability of the changed configuration and the future operating state with high accuracy before changing the power system configuration, and can allow the administrator to monitor and operate the system.

[0060] As described above, the power system management device 10 according to the present embodiment can visualize the steady-state stability of the current configuration of the target power system and the impact on steady-state stability of a change in the configuration of the target power system, such as the connection of renewable energy sources, by superimposing and displaying the steady-state stability index for the current configuration of the target power system and the steady-state stability index for a change in the configuration of the target power system. In particular, the power system management device 10 according to the present embodiment can superimpose and display the power phase angle curve for the current configuration of the target power system and the power phase angle curve for a change in the configuration of the target power system, allowing the administrator to more easily grasp the impact on steady-state stability of a change in the current configuration of the target power system. Furthermore, the power system management device 10 according to the present embodiment can also plot and display the current active power value P and phase angle θ of the target generator, allowing the administrator to monitor the margin of the steady-state stability of the target power system. The multiple overlapping line segments indicate the current values ​​and the respective assumed electromechanical states, and the diagramming method is not limited to line segment representation, but may also be planar color-coded representation.

[0061] As described above, the power system management device 10 according to this embodiment visualizes the steady-state stability limit in real time, taking into account changes in renewable energy sources and loads, based on actual measurements of the target power system. This contributes to the safe and secure operation of the power network. Furthermore, the degree of inertia reduction due to an increase in non-inertial sources, such as renewable energy sources, can be visualized and displayed as a steady-state stability index, contributing to the operation of the power network. From the perspective of steady-state stability, changes in steady-state stability can be visualized by calculating ∂P / ∂θ using measurements of the phase difference between the equivalent infinite bus and the generator-connected bus, such as voltage changes (small disturbances of about 1%) when changing the output of a generator or when changing the tap of an interconnection transformer in a higher-level system. Changes such as raising and lowering the tap of an interconnection transformer occur frequently in daily operations and are therefore easy to detect. This analysis data can be used to support stable generator operation. In addition, by charging electricity generated by renewable energy sources into nearby storage batteries, the apparent amount of transmitted power can be reduced, improving steady-state stability. Alternatively, at reservoir-type or dam-type hydroelectric power plants, power generation can be suppressed and the amount of water stored can be increased, reducing transmitted power and generating power during times when steady-state stability is sufficient. By linking this to prediction functions and visualizing it, stable operation can be supported, just like overload response control, and it can contribute to a decarbonized society.

[0062] 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. [Explanation of symbols]

[0063] 10…Power system management device 11...Communication equipment 12...Arithmetic device 13...Storage device 14...Database 15...Display device 16...Alarm device 17...Input device

Claims

1. an acquisition means for acquiring an output value of each component connected to the power grid; a stability calculation means for calculating a power phase difference angle curve as a steady-state stability index indicating the steady-state stability of the power system based on the output values ​​of the components acquired by the acquisition means; a display means for displaying the steady-state stability index calculated by the stability calculation means, the stability calculation means calculates the power phase difference angle curve in a current configuration of the power system including a renewable energy power source and the power phase difference angle curve when the current configuration of the power system is changed; the display means draws and superimposes a display showing a power phase difference angle curve in a current configuration of the power system and a display showing a power phase difference angle curve when the configuration of the power system is changed; The power system management device, wherein when calculating the power phase difference angle curve in a current configuration of a power system including a renewable energy power source and the power phase difference angle curve when the current configuration of the power system is changed, the stability calculation means calculates a phase difference angle of the renewable energy power source and calculates the power phase difference angle curve using the calculated phase difference angle of the renewable energy power source.

2. The power system management device described in claim 1, wherein the stability calculation means calculates a power phase difference angle curve when the renewable energy power source is added to the current configuration of the power system as a power phase difference angle curve when the current configuration of the power system is changed.

3. The method further comprises: acquiring means for acquiring an output value of a component specified by a user; 3. The power system management device according to claim 1, wherein the stability calculation means calculates the power phase difference angle curve when a configuration of the power system is changed, using the output values ​​of the components acquired by the acquisition means.

4. 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; 2. The power system management device according to claim 1, wherein the display means plots, as the steady-state stability index, a power phase difference angle curve in a current configuration of the power system and a power phase difference angle curve in a case where the configuration of the power system is changed, and displays the plots in a superimposed manner.

5. the stability calculation means further calculates, as the steady-state stability index, a current 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; 5. The power system management device according to claim 4, wherein the display means further renders and superimposes, as the steady-state stability indicators, an indication indicating a current power value and a phase difference angle of the predetermined generator, an indication indicating a steady-state stability limit in a current configuration of the power system, and an indication indicating a steady-state stability limit when the configuration of the power system is changed.

6. A database in which system constants are stored in advance is provided, 6. The power system management device according to claim 1, wherein, when output values ​​cannot be acquired from some of the components of the power system, the stability calculation means estimates the output values ​​of the components from which output values ​​cannot be acquired based on the output values ​​of the components from which output values ​​can be acquired and the system constants stored in the database, and calculates the steady-state stability index using the estimated output values.

7. the acquiring means acquires the output value 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 index based on the output values ​​output at the same time.

8. 8. The power system management device according to claim 1, further comprising: a notification means for determining a steady-state stability in a current configuration of the power system and a steady-state stability when the configuration of the power system is changed, and for issuing a notification when the steady-state stability in the current configuration of the power system or the steady-state stability when the configuration of the power system is changed is equal to or lower than a predetermined value.

9. Obtain the output value of each component connected to the power grid, calculating a power phase difference angle curve as a steady-state stability index indicating the steady-state stability of the power system based on the acquired output values ​​of the components; A power system management method for displaying the calculated steady-state stability index, calculating the power phase difference angle curve in a current configuration of an electric power system including a renewable energy power source and the power phase difference angle curve when the current configuration of the electric power system is changed, and displaying the power phase difference angle curve in the current configuration of the electric power system and the power phase difference angle curve when the configuration of the electric power system is changed in a superimposed manner; A power system management method, comprising: calculating a phase difference angle of a renewable energy power source; and calculating the power phase difference angle curve in a current configuration of the power system including a renewable energy power source; and calculating the power phase difference angle curve when the current configuration of the power system is changed, the power system management method comprising: calculating a phase difference angle of the renewable energy power source; and calculating the power phase difference angle curve using the calculated phase difference angle of the renewable energy power source.

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