JP2024019980A - System management device, system management method and program - Google Patents

Abstract

To minimize a secured capacity of a GFM for providing a control amount and pseudo inertia by selecting and controlling an inverter power supply effective for improving system stability for each assumed system disturbance, and to reduce a calculation load for narrowing down the inverter power supply of a control candidate.SOLUTION: A system management device includes: an identification unit that identifies a power system in a supply area that is an outflow side of a power flow and a consumption area that is an inflow side of the power flow from the point of origin of disturbance based on power flow information; and a control unit for performing control so as to effectively increase an entire capacity of a GFM inverter power supply in the supply area when or before the disturbance occurs.SELECTED DRAWING: Figure 1

Description

Embodiments of the present invention relate to a system management device, a system management method, and a program.

In recent years, the introduction of inverter power supplies that are connected to power grids via power conversion devices (inverter converters) such as solar power generation devices and storage batteries has been progressing.

A Grid-Following (GFL) inverter power source as a conventional inverter power source is controlled to follow a system mainly composed of synchronous generators, and has no inertia or synchronization force. For this reason, there is a concern that stability in systems where inverter power supplies are the main power source will decrease in response to system failures.

As a countermeasure to this problem, Grid-Forming (GFM) inverter power supplies, which mainly constitute the system, are expected to be used.
Furthermore, technology is being developed to enable switching control between GFL and GFM using the same inverter power source.

On the other hand, in order for GFM to provide inertia, it is necessary to ensure charge/discharge capacity for storage batteries and to suppress output for renewable energy power sources. These lead to a loss of charging/discharging and power generation output opportunities, and are a burden to the operator of the inverter power supply.
In order to minimize the capacity to be switched to GFM, it is desirable to effectively select control targets from the viewpoint of system stability and to minimize the burden on the operator.

In the technique described in Patent Document 1, a method is proposed in which the stability of the power system is determined, the necessary inertia and synchronization force are calculated, and the calculated inertia and synchronization force are allocated to a PCS with a pseudo-inertia function. This is carried out for each branch of the power system, and pseudo-inertia is assigned until all faults are stably converged. By combining this with stability calculations, it is possible to output the minimum necessary pseudo-inertia to the PCS (Power Conditioning Subsystem).

In this case, the PCS to be allocated is determined based only on whether inertia can be output based on the output prediction of the renewable energy power source.

Japanese Patent Application Publication No. 2020-188595

However, the target of pseudo-inertia that is effective for improving transient stability differs depending on the fault point, and depending on the arrangement of the fault point and target PCS, the phase difference angle of the synchronous generator increases and becomes unstable due to pseudo-inertia assignment. . As a result, there was a possibility that the required pseudo-inertia was overcalculated.

Furthermore, if an attempt is made to search PCSs to which pseudo-inertia is assigned in a brute-force manner and determine a PCS to be controlled to be stabilized, the total number of PCSs increases, and there is a possibility that the calculation load increases.

The present invention has been made in view of the above, and provides a controlled amount and pseudo-inertia by selecting and controlling an inverter power source that is effective in improving system stability for each assumed system disturbance. The present invention provides a system management device, a system management method, and a program that can minimize the secured capacity of a GFM and reduce the calculation load for narrowing down control candidate inverter power supplies.

The system management device of the embodiment includes an identification unit that identifies the power system into a supply area, which is the outflow side of the power flow, and a consumption area, which is the inflow side of the power flow, based on the power flow information when viewed from the point of occurrence of the disturbance. , a control unit that performs control to effectively increase the overall capacity of the GFM inverter power supply in the supply area when the disturbance occurs.

FIG. 1 is a schematic block diagram of a system management device according to a first embodiment. FIG. 2 is an explanatory diagram of an example of a schematic configuration of a system to be managed by a system management device. FIG. 3 is an explanatory diagram of a first configuration example of the inverter power supply. FIG. 4 is an explanatory diagram of a second configuration example of the inverter power supply. FIG. 5 is an explanatory diagram of an example of an operation processing flowchart in the first embodiment. FIG. 6 is a schematic block diagram of the system management device according to the second embodiment. FIG. 7 is a flowchart of a control target list creation process in the second embodiment. FIG. 8 is an explanatory diagram of an example of an operation processing flowchart in the second embodiment. FIG. 9 is a schematic block diagram of the system management system according to the third embodiment.

[1] First Embodiment FIG. 1 is a schematic block diagram of a system management device according to a first embodiment.
The system management device 10 includes a threshold setting unit 11 that sets standards for determining system stability, an arithmetic unit 12 that performs power flow calculation and dynamic characteristic analysis, and control from among the inverter power supplies that constitute the inverter power supply group 16. It includes a control target selection unit 13 that selects and stores a target machine, and a control unit 14 that outputs a control command to the selected control target machine.

In the above configuration, the system management device 10 functions as a system control device.
Further, each inverter power supply constituting the inverter power supply group 16 is composed of a power supply and a power conversion device. Here, the power source is constituted by a renewable energy power source such as a solar power generation facility or a wind power generation facility, or a power storage facility such as a storage battery or an EV.

Then, the renewable energy power source generates DC power and supplies it to the power conversion device. Further, the power storage equipment supplies the stored power to the power conversion device.
Further, the power conversion device supplies the supplied power to the grid as AC power having an arbitrary voltage and frequency within a range allowable for grid operation.

The system management device 10 can be configured as a single device, or can be configured as separate devices for each function. Moreover, it is also possible to configure it as a monitoring and control system on a core system scale, or as a system that monitors and controls part of the power transmission and distribution system, such as an EMS (energy management system) in a microgrid.
Further, instead of the calculation unit 12, it is also possible to configure it as a calculation result input unit (calculation result input interface unit) that inputs the result of calculation by an external device.

FIG. 2 is an explanatory diagram of an example of a schematic configuration of a system to be managed by a system management device.
In FIG. 2, the system 20 to be managed includes synchronous generators 21a and 21b, inverter power supplies 22a to 22c forming the inverter power supply group 16, step-up transformers 23a to 23b, and step-up transformers 24a to 24c. It includes nodes 25a to 25c and branches 26a to 26c.

In the above configuration, the synchronous generator 21a is connected to the node 25a via the step-up transformer 23a, and the power generated by the synchronous generator 21a is boosted and supplied to the node 25a.
Further, the synchronous generator 21b is connected to the node 25c via a step-up transformer 23b, and the power generated by the synchronous generator 21b is boosted and supplied to the node 25c.
In the above description, it is described that the synchronous generator is connected to the node using one step-up transformer, but the voltage may be changed stepwise using a plurality of transformers.

Here, the configuration of the inverter power supply will be explained.
Inverter power supply 22a is connected to node 25a via step-up transformer 24a, and the power supplied by inverter power supply 22a is boosted and supplied to node 25a.
Inverter power supply 22b is connected to node 25b via step-up transformer 24b, and the power supplied by inverter power supply 22b is boosted and supplied to node 25b.
Inverter power supply 22c is connected to node 25c via step-up transformer 24c, and the power supplied by inverter power supply 22c is boosted and supplied to node 25c.
In this case as well, the inverter power source is described as being connected to the node through one step-up transformer, but the voltage may be changed stepwise using a plurality of transformers.

Here, the inverter power supply will be explained in more detail.
FIG. 3 is an explanatory diagram of a first configuration example of the inverter power supply.
In FIG. 3, an example is shown in which the inverter power supply 22a is configured as a switchable inverter power supply that has both GFL control and GFM control functions and can switch between them.
The control target selection unit 13 of the system management device 10 determines whether, when a disturbance occurs, each inverter power supply is located on the supply area side, which is the outflow side of the power flow, with respect to the disturbance occurrence point, or It is determined whether the area is located on the consumption area side, which is the inflow side of the tidal current.

Based on the identification result, if the inverter power supply of the first configuration example located on the supply area side and operating under GFL control becomes the control target, the switchable inverter power supply is switched to GFM control. Become.
Furthermore, the inverter power supply located on the consumption area side, which is the inflow side of the power flow, is not subject to control.

FIG. 4 is an explanatory diagram of a second configuration example of the inverter power supply.
In FIG. 4, the inverter power supply 22b includes a first inverter power supply 22b-1, a second inverter power supply 22b-2, and a contactor 22b-3.

In this case, a second inverter power source 22b-2 under GFM control is provided in parallel with the first inverter power source 22b-1 whose control is fixed to GFL control or GFM control in a disconnected state by a contactor 22b-3. There is. Note that the parallel array of the second inverter power supplies 22b-2 is not limited to the contactor 22b-3, and it is also possible to use control of a circuit breaker or a gate of a power conversion device.

In the example of FIG. 4, the inverter power supply 22b has a configuration in which one GFM-controlled second inverter power supply 22b-2, which can be paralleled, is connected to the GFL-controlled or GFM-controlled first inverter power supply 22b-1. It is also possible to configure a plurality of two-inverter power supplies 22b-2. Furthermore, a configuration in which the first inverter power source 22b-1 and the second inverter power source 22b-2 are each connected to a node is also conceivable.

When the inverter power supply of the second configuration example becomes a control target, the control unit 14 of the system management device 10 connects the GFM-controlled second inverter power supply 22b-2 to the system.
Specifically, in the example of FIG. 4, when the inverter power supply 22b becomes the control target, the control unit 14 of the system management device 10 controls the contactor 22b-3 to be in the closed state, and Control is performed so that the GFM-controlled second inverter power supplies 22b-2, which are provided in a row, are connected in parallel.

The explanation will be given by returning to FIG. 2 again.
The node 25a and the node 25b are connected by a branch 26b, and the node 25a is further connected to another branch by the branch 26a.
Node 25b and node 25c are connected by a branch 26c.

In this case, assume that the current is flowing in the direction from the node 25a to the nodes 25b and 25c, for example.
Further, it is assumed that the system management device 10 is connected to each of the inverter power supplies 22a to 22c so as to be able to control them.

Next, the operation of the first embodiment will be explained.
FIG. 5 is an explanatory diagram of an example of an operation processing flowchart in the first embodiment.
First, the threshold value setting unit 11 of the system management device 10 sets allowable threshold values of system values such as the phase difference angle, voltage, and frequency of the synchronous generators for each synchronous generator 21a, 21b, nodes 25a to 25c, and branches 26a to 26c. is set (step S11).

The calculation unit 12 of the system management device 10 performs power flow calculation, and calculates and stores the power flow and voltage phase angle of each branch (step S12).
The calculation unit 12 performs dynamic characteristic analysis for each assumed disturbance such as a system accident (step S13).

Subsequently, the calculation unit 12 determines whether there is an unstable response such as a deviation from the allowable threshold set by the threshold setting unit 11 or a step-out of the synchronous generator (step S14).
In this case, when a disturbance that deviates from the allowable threshold is discovered through analysis, it is treated as a disturbance occurring.

In the judgment in step S14, if the allowable threshold set by the threshold setting unit 11 has not been exceeded and an unstable response such as a step-out of the synchronous generator has not occurred (step S14; No), perform dynamic characteristic analysis under the following disturbance.

In the judgment of step S14, if there is a disturbance that causes an unstable response such as deviation from the allowable threshold set by the threshold value setting unit 11 or step-out of the synchronous generator (step S14; Yes), a countermeasure event In the disturbance set as a countermeasure event, the calculation unit 12 refers to the power flow direction or voltage phase angle from the result of power flow calculation, and the control target selection unit 13 selects a disturbance that is on the supply side of the power flow as seen from the disturbance occurrence point. The inverter power supply is set as a control candidate machine (step S15).

For example, if the disturbance occurrence point is the branch 26b, the inverter power supply 22a on the power flow supply side as viewed from the disturbance occurrence point is set as the control candidate machine.
Next, a target machine to which a control command is actually output is selected from among the control candidate machines (step S16).

In this case, the selection criterion is the inverter power source near the node whose system value deviates the most from the allowable threshold value, but it may also be the inverter power source closest to or at the end of the disturbance point.

The system is simulated assuming that the selected inverter power source is controlled (for example, the switchable inverter power source is switched to GFM control), and the dynamic characteristic analysis is performed again at the countermeasure event (step S17). .

Subsequently, the calculation unit 12 determines whether an unstable response occurs, such as deviating from the allowable threshold set by the threshold setting unit 11 or causing the synchronous generator to step out (step S18).

In the judgment in step S18, if there is an unstable response such as deviating from the allowable threshold set by the threshold setting unit 11 or the synchronous generator is out of synchronization (step S18; Yes), that is, the countermeasure event still remains. If the control does not converge stably, the process returns to step S16, where the next target aircraft is selected from among the control candidate aircraft, and the above-described process is performed again.

If it is determined in step S18 that the process has converged to stability, the dynamic characteristic analysis for each disturbance is performed again while maintaining the simulated state of the inverter power supply after control, and the above-described processing is then performed. If all disturbances do not deviate from the tolerable threshold and unstable responses such as synchronous generator step-out do not occur, the control unit 14 controls the inverter power supply set for the controlled machine. A command is output (step S19), and the process is temporarily terminated.
The above-described processing is performed periodically and operates to ensure stable operation of the system at all times.

Here, more specific operations will be explained.
As described above, the current is flowing from the node 25a to the nodes 25b and 25c.
For example, assume that as a result of dynamic characteristic analysis performed on the short circuit accident at the branch 26c in step S13, the frequency and voltage at the nodes 25a and 25b deviate from the allowable threshold set in step S11.

As a result, the control target selection unit of the system management device 10 functions as an identification unit, and determines whether each inverter power supply is located on the supply area side, which is the outflow side of the power flow, with respect to the disturbance occurrence point when a disturbance occurs. Or, it is determined whether the disturbance point is located on the consumption area side, which is the inflow side of the tidal current, with respect to the disturbance occurrence point.
Then, the inverter power source located on the supply area side and the inverter power source of the first configuration example or the inverter power source of the second configuration example described above is set as a control candidate machine.

More specifically, since the power flow of the branch 26c at the disturbance occurrence point (fault point) flows from the node 25b to the node 25c, in step S15, the inverter power supply 22a on the tidal flow supply side as seen from the disturbance occurrence point , 22b are set as control candidate machines.

In step S16, if the simulated node with the largest frequency fluctuation is the node 25a, the inverter power supply 22a connected to the node 25a is set as the control target.

In step S17, the dynamic characteristics when the control circuit is switched to GFM or when the GFM power supply is connected in parallel to the grid are simulated again, and if the grid values such as frequency and voltage are within the allowable thresholds in all branches, , dynamic characteristic analysis for all disturbances is performed again in step S13.

Then, when the system values for all disturbances fall within the allowable threshold, a control command is output to the inverter power supply 22a set to the controlled object machine. Here, the condition for outputting a control command is that all disturbances converge stably, but a threshold value is set for the number of disturbances, and when a certain number of disturbances or more converges stably, a control command is output. However, stabilization control may be considered as a separate countermeasure for the remaining disturbances.

By the way, in systems where inverter power supplies are the main power source, stability against disturbances such as system failures decreases, and inverter power supplies with pseudo-inertia have been developed as a countermeasure. Developing power sources may actually worsen system stability or lead to excessive inertia.

On the other hand, by applying the same method as in the first embodiment, the arrangement of inertia can be optimized and the system stability can be improved with the minimum amount of control and amount of inertia secured.

[2] Second Embodiment FIG. 6 is a schematic block diagram of a system management device according to a second embodiment.
In FIG. 6, the same parts as in the first embodiment of FIG. 1 are given the same reference numerals.

The system management device 10A includes a threshold setting unit 11 that sets standards for determining system stability, an arithmetic unit 12A that performs power flow calculation and dynamic characteristic analysis, and control from among the inverter power supplies that constitute the inverter power supply group 16. It includes a control target selection unit 13 that selects and stores a target machine, and a control unit 14 that outputs a control command to the selected control target machine.

The second embodiment has the same basic configuration as the first embodiment, but includes tidal flow monitoring terminals 17-1 to 17-n (n is a natural number of 2 or more) that monitor tidal currents, and Disturbance detection terminals 18-1 to 18-m (m is a natural number of 2 or more) that detect positions and disturbance contents are installed at a plurality of substations and switchyards.

The current monitoring terminals 17-1 to 17-n communicate with the control target selection section 13, and the disturbance detection terminals 18-1 to 18-m communicate with the control section 14.

In this case, the tidal current monitoring terminals 17-1 to 17-n and the disturbance detection terminals 18-1 to 18-m may have both functions in one device, or they may have the functions described in the system management device 10A. may also be provided on the terminal side.

FIG. 7 is a flowchart of a control target list creation process in the second embodiment.
Further, FIG. 8 is an explanatory diagram of an example of an operation processing flowchart in the second embodiment.

First, the threshold value setting unit 11 of the system management device 10A sets allowable threshold values of system values such as the phase difference angle, voltage, and frequency of the synchronous generators for each synchronous generator 21a, 21b, nodes 25a to 25c, and branches 26a to 26c. is set (step S11).

The power flow monitoring terminals 17-1 to 17-n measure the power flow and voltage phase angle of each branch and periodically transmit them to the system management device 10A (step S12A).
The calculation unit 12A performs dynamic characteristic analysis for each assumed disturbance such as a system accident (step S13).

Subsequently, the calculation unit 12A determines whether there is an unstable response such as a deviation from the allowable threshold set by the threshold setting unit 11 or an out-of-step of the synchronous generator (step S14).

In the judgment in step S14, if the allowable threshold set by the threshold setting unit 11 has not been exceeded and an unstable response such as a step-out of the synchronous generator has not occurred (step S14; No), perform dynamic characteristic analysis under the following disturbance.

In the judgment in step S14, if an unstable response occurs such as deviating from the allowable threshold set by the threshold value setting unit 11 or the synchronous generator loses synchronization (step S14; Yes), set as a countermeasure event, In a disturbance set as a countermeasure event, the control target selection unit 13 determines the supply of power flow from the point of occurrence of the disturbance by referring to the power flow direction or voltage phase angle from the power flow information measured by the power flow monitoring terminals 17-1 to 17-n. The inverter power source on the side is set as a control candidate machine (step S15).

For example, if the disturbance occurrence point is the branch 25b, the inverter power supply 22a on the power flow supply side as viewed from the disturbance occurrence point is set as the control candidate machine.
Next, the control unit 14 selects a target machine to actually output a control command from among the control candidate machines, adds it to the control target list, and updates the control target list. Furthermore, the inverter power supply is excluded from the control candidate machines (step S16A).

In this case, the selection criterion is the inverter power source near the node whose system value deviates the most from the allowable threshold value, but it may also be the inverter power source closest to or at the end of the disturbance point.

The system is simulated assuming that the selected inverter power source is controlled (for example, the switchable inverter power source is switched to GFM control), and the dynamic characteristic analysis is performed again at the countermeasure event (step S17). .

Subsequently, the calculation unit 12 determines whether an unstable response occurs, such as deviating from the allowable threshold set by the threshold setting unit 11 or causing the synchronous generator to step out (step S18).

In the judgment in step S18, if an unstable response occurs such as deviating from the allowable threshold set by the threshold setting unit 11 or the synchronous generator steps out (step S18; Yes), that is, the countermeasure event is still occurring. If the control does not converge stably, the process returns to step S16A, selects the next target aircraft from among the control candidate aircraft, and then performs the above-described process again.

If it is determined in step S18 that the process has converged to stability, the dynamic characteristic analysis for each disturbance is performed again while maintaining the simulated state of the inverter power supply after control, and the above-described processing is then performed. If all the disturbances do not deviate from the allowable threshold and unstable responses such as the synchronous generator stepping out do not occur, the process of updating the controlled object list is temporarily terminated.
The above-described process is performed periodically, and the controlled object list is always updated to the latest state.

In parallel with the above processing, the control unit 14 communicates with the disturbance detection terminals 18-1 to 18-m to inform the disturbance detection terminal 18-1 that the grid disturbance event X has occurred at any point in the grid. -18-m is detected (step S21).
In the judgment in step S21, if all of the disturbance detection terminals 18-1 to 18-m have not detected the system disturbance event X (step S21; No), the terminal enters a standby state.

In the judgment in step S21, if any of the disturbance detection terminals 18-1 to 18-m detects that the system disturbance event X has occurred (step S21; Yes), the control unit 14 updates the control target list. With reference to this, a control command is output to the inverter power supply to be controlled corresponding to the system disturbance event X (step S22), and the process is temporarily terminated.

These processes are repeated in sequence to ensure stable operation of the system at all times.

In the above explanation, tidal currents were detected by collecting measurement data from tidal current monitoring terminals 17-1 to 17-n, but considering that tidal currents have patterns depending on the season, time of day, and weather, multiple tidal currents were created. The pattern may be used as tidal flow information and the tidal current monitoring terminal may be omitted.

In this case, the calculations in steps S11 to S18 are performed for each tidal current pattern in advance to create and store a list of controlled aircraft, and based on the season, time, weather forecast, etc., the tidal current of the day is linked to the tidal current pattern, and the disturbance is detected. What is necessary is to schedule the inverter power supply to be controlled when this occurs.

According to the second embodiment, in response to a system fault, one of the inverter power supplies is set as a control target, as in the first embodiment, and is stored as a control target list.
When a branch system failure is detected by the disturbance detection terminals 18-1 to 18-m installed in the nodes 25a to 25c, etc., the control unit 14 calls up the list of control targets stored in the control unit 14, and issues control commands to the inverter power supplies to be controlled. is output.

Therefore, compared to the first embodiment, according to the second embodiment, a control command is output only when a disturbance occurs, so that the amount of control and the amount of inertia secured can be further suppressed.

[3] Third Embodiment FIG. 9 is a schematic block diagram of a system management system according to a third embodiment.
In FIG. 9, the same parts as in FIG. 6 are given the same reference numerals.
The power grid management system of the third embodiment differs from each of the above embodiments in that it uses only power flow information and does not use dynamic characteristic analysis.

In the third embodiment, based on the power flow information from the power flow monitoring terminals 17-1 to 17-n, the control target selection unit 13 selects an inverter power supply to be controlled that corresponds to an assumed disturbance such as a system accident, It is periodically transmitted to the disturbance detection terminals 18-1 to 18-m. The disturbance detection terminals 18-1 to 18-m store the controlled object list.

When the disturbance detection terminals 18-1 to 18-m installed at the site detect a target disturbance, control commands are issued to the corresponding inverter power supplies forming the inverter power supply group 16 based on the stored control target list. Output. In the third embodiment, the disturbance detection terminals 18-1 to 18-m have the functions of the control unit 14 in the first embodiment or the second embodiment.

In this case, it is also possible for the power flow monitoring terminals 17-1 to 17-n to be installed representatively so as to separate the system into several areas and monitor the power flow between the areas.

Further, similarly to the second embodiment, the disturbance details and position are transmitted from the disturbance detection terminals 18-1 to 18-m to the system management device 10B, and the inverter power supply group 16 is configured from the control unit 14 provided in the system management device 10B. It is also possible to configure a configuration in which a control command is output to a corresponding inverter power supply that is a control target.

In the third embodiment, similarly to the first embodiment, inverter power supplies that are candidates for control in response to system disturbances are registered and stored in a control object list.

When the disturbance detection terminals 18-1 to 18-m installed in the nodes 25a to 25c etc. detect a system disturbance, a corresponding action is taken based on the control target list stored in the disturbance detection terminals 18-1 to 18-m. A control command is output to the inverter power supply.

According to the third embodiment, in addition to the effects of the second embodiment, up and down communication is reduced and support can be carried out locally, so faster control is possible. Furthermore, since dynamic characteristic analysis is not used, calculation load can be reduced.

The system management device of this embodiment includes a control device such as a CPU, a storage device such as a ROM (Read Only Memory) or a RAM, an external storage device such as an HDD or a CD drive device, and a display device such as a display device. It is equipped with input devices such as a keyboard and mouse, and can be configured as a hardware configuration using an ordinary computer.

The program executed by the system management device of this embodiment is a file in an installable or executable format, and is stored in a semiconductor storage device such as a USB memory, an SSD (Solid State Drive), or a DVD (Digital Versatile Disk). Provided recorded on a computer-readable recording medium.

Further, the program executed by the system management device of this embodiment may be stored on a computer connected to a network such as the Internet, and may be provided by being downloaded via the network. Further, the program executed by the system management device of this embodiment may be provided or distributed via a network such as the Internet.

Further, the program of the system management device of this embodiment may be configured to be provided by being incorporated in a ROM or the like in advance.

The program executed by the system management device of this embodiment has a module configuration including the above-mentioned units (threshold value setting unit, calculation unit, control target selection unit, control unit), and the actual hardware is the CPU ( When the processor (processor) reads the program from the storage medium and executes it, each of the above sections is loaded onto the main storage device, and the threshold setting section, calculation section, control object selection section, and control section are generated on the main storage device. It looks like this.

Although several embodiments of the invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included within the scope and gist of the invention, as well as within the scope of the invention described in the claims and its equivalents.

10, 10A, 10B Grid management device 11 Threshold setting unit 12, 12A, 12B Calculation unit 13 Control target selection unit 14 Control unit 16 Inverter power supply group 17-1 to 17-n Power flow monitoring terminal 18-1 to 18-m Disturbance detection Terminal 20 System 21a, 21b Synchronous generator 22a-22c Inverter power supply 22b-1 First inverter power supply 22b-2 Second inverter power supply 22b-3 Contactor 23a, 23b Step-up transformer 24a-24c Step-up transformer 25a-25c Node 26a-26c Branch

Claims (15)

an identification unit that identifies the power system into a supply area, which is the outflow side of the tidal flow, and a consumption area, which is the inflow side of the tidal flow, based on the tidal flow information when viewed from the point of occurrence of the disturbance;
a control unit that performs control to effectively increase the overall capacity of a Grid-Forming (GFM) inverter power supply in the supply area when the disturbance occurs;
A system management device equipped with. The power system has a switchable inverter power source that has both Grid-Following (GFL) control and GFM control functions and can switch between them,
The control unit switches the switchable inverter power supply located on the supply area side and operating under GFL control to GFM control when the disturbance occurs.
The system management device according to claim 1. The control unit connects a GFM-controlled inverter power supply in parallel to the grid when the disturbance occurs;
The system management device according to claim 1. The identification unit divides the entire system into a plurality of areas in advance and uses, as the tidal flow information, a tidal flow measurement value of a branch representing the tidal flow between each area.
The system management device according to claim 1. The identification unit uses a power flow measurement value of the core system as the power flow information,
The system management device according to claim 1. The identification unit uses, as the power flow information, a power flow calculation result calculated by inputting grid information and predicted values or past actual values of power demand and power generation output.
The system management device according to claim 1. The identification unit uses, as the tidal current information, a plurality of tidal current patterns created in advance for each tidal-related factor such as season, time, and weather.
The system management device according to claim 1. The control unit presets allowable threshold values for system values such as phase difference angle, voltage, and frequency of the synchronous generator, and detects that the disturbance that deviates from the allowable threshold based on the results of simulating dynamic characteristics. In this case, the disturbance shall be treated as the occurrence of the disturbance;
The system management device according to claim 1. The control unit selects one or more of the switchable inverter power supplies on the power supply side as viewed from the disturbance occurrence point, and selects a combination of control targets for switching to GFM control from among the selected switchable inverter power supplies. selecting the switchable inverter power supply, simulating the dynamic characteristics after control for each of the combinations, and actually switching to the GFM control;
The system management device according to claim 2. The control unit selects one or more GFM inverter power supplies that are in a disconnected state on the power supply side when viewed from the disturbance occurrence point, and selects a combination to be paralleled from among the selected GFM inverter power supplies, simulating the dynamic characteristics after control for each combination and selecting the GFM inverter power supplies to be actually paralleled;
The system management device according to claim 3. A system management method in a power supply system having a GFM inverter power supply or a switchable inverter power supply that has both GFL control and GFM control functions and can switch between them,
Based on the tidal flow information, the power system is divided into a supply area, which is the outflow side of the tidal current, and a consumption area, which is the inflow side of the tidal current, when viewed from the point of occurrence of the disturbance;
controlling to effectively increase the overall capacity of the GFM inverter power supply in the supply area when the disturbance occurs;
A system management method with The process of controlling the GFM inverter power supply so as to effectively increase the overall capacity is to select a new parallel GFM inverter power supply or a combination of the switchable inverter power supplies to be switched to GFM control, and to control the GFM inverter power supply after the control for each combination. simulating dynamic characteristics and actually selecting the GFM inverter power supplies to be paralleled or the switchable inverter power supplies to be switched to GFM control;
The system management method according to claim 11. A process for presetting allowable threshold values for system values such as phase difference angle, voltage, frequency, etc. of the synchronous generator,
In the controlling step, when the disturbance that deviates from the allowable threshold is detected from the result of simulating dynamic characteristics, the disturbance is treated as an occurrence.
The system management method according to claim 11 or claim 12. A program for controlling, by computer, a system management device that controls a power system having a GFM inverter power supply or a switchable inverter power supply that has both GFL control and GFM control functions and can switch between them,
means for causing the computer to identify, based on the tidal flow information, the power system into a supply area, which is the outflow side of the tidal current, and a consumption area, which is the inflow side of the tidal current, when viewed from the point of occurrence of the disturbance;
means for controlling to effectively increase the overall capacity of the GFM inverter power supply in the supply area when the disturbance occurs;
A program that makes it work. Equipped with means for presetting allowable threshold values for system values such as phase difference angle, voltage, frequency, etc. of the synchronous generator,
The controlling means treats the disturbance as occurring when the disturbance that deviates from the allowable threshold is detected from the result of simulating dynamic characteristics.
The program according to claim 14.

Images