JP7293084B2 - stabilization system - Google Patents

Description

The present embodiment relates to a power system stabilization system that controls the output amount of a renewable energy power generator in a power system including a synchronous generator and a renewable energy power generator to ensure stability of the power system.

2. Description of the Related Art A power system stabilization system is known that controls the output amount of a renewable energy power generation device in a power system based on collected power system information in order to prevent a generator from going out of step at the time of an accident.

JP 2015-130777 A JP 2016-208826 A

In recent years, the introduction of renewable energy power generation equipment using renewable energy such as solar power generation and wind power generation is progressing. A power grid is connected to a large number of renewable energy generators. For this reason, the number of operating synchronous generators such as thermal and hydraulic power generators connected to the electric power system tends to decrease more than before.

A decrease in the number of operating synchronous generators connected to the power system, such as thermal power and hydraulic power, is thought to reduce the synchronous stability and voltage stability of power generation equipment, making it more important to operate the power system stably. expected to be difficult. The control method of the conventional power system stabilization system, which finds a stable system state by stopping the equipment (electrical control), may not be suitable for controlling such a power system with a small number of synchronous generators in operation. .

In a power system with a small number of operating synchronous generators, the ratio of the amount of decrease in the output power of the synchronous generators to the entire power system is higher than in a conventional power system. For example, when power control is performed in the event of an accident or the like, the power system may become unstable. This is because if such control is performed, the proportion of the synchronous generator in the entire electric power system may further decrease, the number of voltage maintenance sources may decrease, and the inertia and synchronizing force may decrease.

Therefore, in a power system with a small number of synchronous generators in operation, it is possible to reduce or stop the output of renewable energy power generation equipment instead of synchronous generators to ensure a certain amount of synchronous generator output. It can be said that it is desirable. However, there is a problem that the stability of the electric power system cannot be efficiently ensured by randomly selecting renewable energy power generation devices and controlling to reduce or stop the output amount. It is necessary to select a renewable energy power generation device that can efficiently ensure the stability of the power system and perform control to reduce the output amount.

There is also the problem that when control is performed to reduce or stop the output of a renewable energy power generation device, a loss is incurred by the power generation company that owns the renewable energy power generation device that is subject to control. Alternatively, the power transmission and distribution business operator may have to compensate for the loss incurred by the power generation business operator. For this reason, it is desirable to minimize the reduction or suspension of the output amount of the renewable energy power generation device to be controlled. On the other hand, it is important to ensure the synchronous stability of the power system when an accident occurs.

In view of the above problems, the present embodiment aims to provide a power system stabilization system that can select a renewable energy power generation device that reduces or stops the output amount and can efficiently ensure the stability of the power system. aim.

The power system stabilization system of this embodiment is characterized by having the following configuration.
(1) A stabilization index change amount calculation unit that calculates the amount of change in the synchronization stability stabilization index when the supply of power supplied from a plurality of renewable energy power generation devices in a power system that supplies power is reduced. .
(2) A renewable energy group determination unit that classifies the plurality of renewable energy power generation devices into groups based on the amount of change in the stabilization index calculated by the amount of change in stabilization index calculation unit.
(3) necessary for stabilization at the occurrence of an assumed accident for each group of the plurality of renewable energy power generation devices classified by the renewable energy group determination unit for each of the plurality of power flow cross sections of the power system; An estimation model creation unit that calculates an amount of decrease in output power and constructs an estimation model for estimating the amount of decrease for each of the groups of the renewable energy power generation devices based on the node branch information of the power flow cross section.
(4) A control amount distribution unit that distributes the decrease amount for each group of the renewable energy power generation devices estimated by the estimation model creation unit to the renewable energy power generation devices within the group.
(5) determining the group of the renewable energy power generation devices to be controlled when an accident occurs based on the reduction amount distributed by the control amount distribution unit; control unit that directs to

An overall diagram showing the configuration of a power system using the power system stabilization system according to the first embodiment. Diagram showing the functional flow of the power system stabilization system according to the first embodiment The figure which shows the presumed model created by the calculating part of the power system stabilization system concerning 1st Embodiment. FIG. 4 is a diagram for explaining calculation of a control amount of output power by the power system stabilization system according to the first embodiment; A diagram for explaining the operation of grouping renewable energy power generation devices by the power system stabilization system according to the first embodiment.

[1. First Embodiment]
[1-1. overall structure]
FIG. 1 is an overall diagram showing the configuration of a power system using a power system stabilization system 1 according to the first embodiment. In this embodiment, when there are a plurality of devices or members having the same configuration, the same numbers are assigned to them for description, and when describing each device or member having the same configuration, a common number is used. are distinguished by subscripting them with a hyphen. In this embodiment, the amount of control applied to the output power to be reduced by the renewable energy power generation device 6 is called the amount of reduction. The control amount for the reduced output power of the renewable energy power generation device 6 may be, for example, a stop amount of string power for stopping the output of the renewable energy power generation device 6, which is a solar power generation device.

In FIG. 1, a synchronous generator 4-1 is connected to a power system 9 via a transformer 3-1, a circuit breaker 5-1, a transmission line 2-2, and a transmission line 2-1. Similarly, the synchronous generator 4-2 is connected to the electric power system 9 via the transformer 3-2, the circuit breaker 5-2, the transmission line 2-2 and the transmission line 2-1, and the synchronous generator 4-3 is It is connected to a power system 9 via a transformer 3-3, a circuit breaker 5-3, a transmission line 2-2 and a transmission line 2-1.

The synchronous generators 4-1, 4-2, and 4-3 are composed of thermal power, hydraulic power, or other power generation devices. Transformers 3-1, 3-2 and 3-3 convert voltages of electric power output from synchronous generators 4-1, 4-2 and 4-3, respectively, into predetermined voltages.

The circuit breakers 5-1, 5-2 and 5-3 are composed of switches that cut off power, and cut off the power output from the synchronous generators 4-1, 4-2 and 4-3, respectively. The circuit breakers 5-1, 5-2, and 5-3 are connected to the power system stabilization system 1 via communication lines, and are controlled by the power system stabilization system 1 to open and close.

The renewable energy power generation device 6-1 is connected to the power system 9 via the transformer 3-4, and the renewable energy power generation device 6-2 is connected to power via the transformer 3-5 and the transmission line 2-1. It is connected to system 9. Transformers 3-4 and 3-5 convert the voltages of the electric power output from renewable energy power generators 6-1 and 6-2, respectively, into predetermined voltages.

The renewable energy generators 6-1 and 6-2 are connected to the power system stabilization system 1 via communication lines, and the power system stabilization system 1 controls the amount of output.

An accident detection device 7-1 is installed on the transmission line 2-1, and an accident detection device 7-2 is installed on the transmission line 2-2. The accident detection devices 7-1 and 7-2 are composed of a ground fault detection device, an abnormal voltage/current detection device, and the like. The accident detection devices 7-1 and 7-2 are connected to the power system stabilization system 1 via communication lines, and transmit accident information to the power system stabilization system 1. FIG.

Information collection devices 8-6 and 8-7 are installed on the transmission line 2-1, and information collection devices 8-8 and 8-9 are installed on the transmission line 2-2. An information collection device 8-1 is installed in the synchronous generator 4-1, an information collection device 8-2 is installed in the synchronous generator 4-2, and an information collection device 8-3 is installed in the synchronous generator 4-3. An information collection device 8-4 is installed in the renewable energy power generation device 6-1, and an information collection device 8-5 is installed in the renewable energy power generation device 6-2.

Information collecting devices 8-1 to 8-9 are configured by measuring devices for detecting power frequency, phase, voltage, current, active power, and reactive power. Information collecting devices 8-1 to 8-9 are connected to power system stabilization system 1 through communication lines. The information collecting devices 8-1 to 8-9 detect power frequency, phase, voltage, current, active power, and reactive power, and transmit them to the power system stabilization system 1 as power information.

[1-2. Configuration of power system stabilization system 1]
The power system stabilization system 1 is a control device that calculates the amount of decrease and/or the amount of stoppage that is the control amount of the output power at the time of occurrence of an accident, and determines the target renewable energy power generator 6 . The power system stabilization system 1 has an arithmetic unit 10 and a control unit 20 . The calculation unit 10 and the control unit 20 are each configured by a computer and connected inside the power system stabilization system 1 . Alternatively, the calculation unit 10 and the control unit 20 are integrally configured by a computer. The power system stabilizing system 1 is installed in a command room such as a power supply command center, a system control center, or a central control center that monitors and controls the power system.

(A, configuration of calculation unit 10)
The calculation unit 10 is configured by a computer, and is connected to the control unit 20 inside the power system stabilization system 1 . The calculation unit 10 receives power information from the information collection devices 8-1 to 8-9 connected via the communication line, and determines the renewable energy power generation device 6 that reduces the output power when an accident occurs and the output power. Determine the amount of reduction.

Each part of the calculation unit 10 in the functional flow shown in FIG. 2 is configured by hardware or software modules in the computer. The calculation unit 10 has a stabilization index change amount calculation unit 11 , a renewable energy group determination unit 12 , an estimation model creation unit 13 , and a control amount distribution unit 14 .

(Stabilization index change amount calculator 11)
The stabilization index change amount calculation unit 11 calculates the amount of change in the stabilization index of synchronization stability when the supply of power supplied from the plurality of renewable energy power generation devices 6 in the power system 9 that supplies power is reduced. calculate.

(Renewable energy group determination unit 12)
The renewable energy group determination unit 12 groups (sorts into groups) the plurality of renewable energy power generators 6 based on the amount of change in the stabilization index calculated by the stabilization index change amount calculation unit 11 .

(Estimation model creation unit 13)
The estimation model creation unit 13 calculates the stability at the occurrence of an assumed accident for each group of the plurality of renewable energy power generation devices 6 grouped by the renewable energy group determination unit 12 for each of the plurality of power flow cross sections of the power system 9. An estimation model is constructed for calculating the amount of decrease in the output power required for conversion, and estimating the amount of decrease for each group of renewable energy power generation devices 6 based on the node branch information of the power flow cross section.

(Controlled amount distribution unit 14)
The control amount distribution unit 14 distributes the amount of decrease for each group of the renewable energy power generation devices 6 estimated by the estimation model creation unit 13 to the renewable energy power generation devices 6 within the group.

(B, configuration of control unit 20)
The control unit 20 is configured by a computer, and is connected to the calculation unit 10 inside the power system stabilization system 1 . The control unit 20 is connected to the breakers 5-1, 5-2, 5-3 and the renewable energy generators 6-1, 6-2 via an information transmission network, and transmits and receives command values and set values. The control unit 20 determines a group of renewable energy power generation devices 6 to be controlled when an accident occurs based on the amount of decrease distributed by the control amount distribution unit 14 of the calculation unit 10, and can reproduce the amount of decrease in output power. Instruct the energy generator 6 .

The above is the configuration of the power system stabilization system 1 .

[1-2. action]
Next, the outline of the operation of the power system stabilization system 1 of the present embodiment will be described based on FIGS. 1 to 5. FIG. Stabilization index change amount calculation unit 11, renewable energy group determination unit 12, estimation model creation unit 13, control amount allocation unit configured by hardware or software modules in calculation unit 10, related to the functional flow shown in FIG. 14 and the control unit 20 perform the following calculations and controls.

In accordance with the functional flow shown in FIG. 2, the computing unit 10 prevents the synchronous generator 4 from stepping out and stabilizes the power system for each assumed accident. Make 6 choices. The computing unit 10 also selects the synchronous generator 4 to be disconnected. , the control unit 20 determines a group of renewable energy power generation devices 6 to be controlled when an accident occurs based on the distributed decrease amount calculated by the calculation unit 10, and determines the amount of decrease in output power as a renewable energy The power generator 6 is instructed. The control unit 20 also instructs the synchronous generator 4 to be disconnected to disconnect. The power system stabilization system 1 in this embodiment preferentially reduces or stops the output power of the renewable energy power generator 6 in order to stabilize the power system.

First, a plurality of training data necessary for constructing an estimation model are prepared. A plurality of teacher data are prepared for each power flow cross section to be calculated. In order to ensure the estimation accuracy of the estimation model, it is desirable to prepare as many training data as possible for tidal flow cross sections having tidal current states with different characteristics. The teacher data is set in the calculation unit 10 by the operator. The calculation unit 10 constructs an estimation model using the estimation model creation unit 13 based on the teacher data.

The system configuration (topology) of the power system 9 configured by the open/closed state of the circuit breaker 5 in the transmission line, etc., and the operation stop state of the synchronous generator 4 are different. 9 will be discretely different. The estimation model is constructed for each power flow cross-section classified in advance by the calculation unit 10 according to the system configuration (topology) of the power system 9 and the shutdown state of the synchronous generator 4 . As a result, a highly accurate estimation model with little error in the amount of decrease in output power is constructed. FIG. 3 shows the process of creating an estimation model for one power flow section classification and the process of calculating the control amount using the estimation model.

The calculation unit 10 performs power flow calculation and transient stability calculation for each power flow cross section, and calculates the amount of decrease in the output power of the renewable energy power generation device 6 required for stabilization. The renewable energy power generators 6 are grouped based on the stabilization index change amount described later, and the reduction amount required for each group is calculated.

The calculation unit 10 inputs power flow calculation results such as node voltage, power, and branch power flow for each assumed accident and for each classified power flow cross section. Generates training data that outputs the amount of decrease. The calculation unit 10 applies a statistical model such as a regression equation or machine learning to build an estimation model.

By inputting the power flow calculation result of the power flow cross section for which the output power is reduced and the assumed accident into the estimation model, the similarity between the system configuration (topology) of the power system 9 and the shutdown state of the synchronous generator 4 Based on this, the relevant load flow section classification is selected. A required reduction amount of the output power for each group of the renewable energy power generation devices 6 for the power flow section classification selected by the calculation unit 10 is calculated.

The calculation unit 10 selects the group of the renewable energy power generation devices 6 with the smallest reduction amount and the highest stabilization effect as the group of the renewable energy power generation devices 6 to be controlled when an accident occurs. When an accident occurs, the control unit 20 applies the calculated amount of decrease to the nodes of the renewable energy power generation devices 6 belonging to the group of the selected control target renewable energy power generation devices 6 as a stabilizing effect. distributed in descending order of After distributing the decrease amount to the node, the control unit 20 further distributes the surplus decrease amount to the renewable energy power generators 6 included in the node.

As the transient stability analysis by the calculation unit 10, evaluation of transient stability in the backbone system of the electric power system 9 is mainly performed. From the viewpoint of reducing calculation difficulty and shortening calculation time, details of the electric power system 9 are not simulated, and are generally treated as a system model in which a voltage class of 66 kV or less is aggregated and simulated as shown in FIG. The model shown in FIG. 4 is an example of the concept of voltage classes when creating a system model. Voltages below 66 kV, excluding the synchronous generator 4, are aggregated and simulated, and voltage classes higher than 66 kV are simulated in detail.

Renewable energy power generation devices 6 such as solar power generation devices are generally connected to a voltage class of 66 kV or less, so renewable energy power generation devices 6 connected to a system of 66 kV or less are aggregated and installed at a 66 kV node. It is effective to create a phylogenetic model based on

The control unit 20 determines the node of the renewable energy power generation device 6 to be controlled and the reduction amount necessary for stabilization, and determines the renewable energy power generation device 6 belonging to the selected node (in FIG. 4, the 66 kV system or less) Allocate the reduction to the renewable energy generator 6). The amount of reduction is distributed by equal distribution, distribution according to installed capacity, rotational distribution based on fairness, and the like.

(Arithmetic control by stabilization index change amount calculator 11)
The stabilization index change amount calculation unit 11 of the calculation unit 10 calculates a stabilization index of synchronization stability when the supply of power supplied from the plurality of renewable energy power generation devices 6 in the power system 9 that supplies power is reduced. Calculate the amount of change in

First, the stabilization index change amount calculator 11 classifies the power flow cross section based on the system configuration (topology) of the power system 9 and the shutdown state of the synchronous generator 4 . The stabilization index change amount calculation unit 11 collects a number of system cross sections of the power system 9 from, for example, the operation data for the past several days, and based on the SV information, "system configuration (topology) of the power system 9" and " The power flow cross section is classified based on the degree of similarity of "the shutdown state of the synchronous generator 4".

Power flow cross-sections determined to be similar by the two indices of "system configuration (topology) of power system 9" and "shutdown state of synchronous generator 4" are grouped together. The degree of similarity of the "system configuration (topology) of the power system 9" is determined using, for example, the calculated short-circuit impedance from the assumed accident point as an index. Based on the system configuration (topology) of the power system 9 in the past, a short-circuit impedance that causes a significant difference in system stability is set in the calculation unit 10 in advance as a threshold for grouping.

The degree of similarity of the "shutdown state of the synchronous generators 4" is determined by comparing the shutdown states of the synchronous generators 4 as vectors of discrete values. The degree of similarity of the "shutdown state of the synchronous generator 4" is obtained by, for example, selecting the synchronous generator 4 that becomes unstable for each accident condition based on past calculation results of the stability of the system, and selecting the selected synchronous generator. It is determined by the shutdown state of the machine 4.

After classifying the power flow cross section as described above, the stabilization index change amount calculation unit 11 of the calculation unit 10 calculates the stabilization index change amount S used for grouping the renewable energy power generation devices 6 by the renewable energy group determination unit 12. is performed for each classification of the power flow cross section of the power system 9 . The stabilizing index change amount S is an index that indicates the stabilizing effect of reducing or stopping the output power of the renewable energy power generation device 6 . As an example, the stabilization index change amount S is calculated by (Equation 1).

The stabilization index change amount Si is calculated for each assumed accident case and power flow section classification. FIG. 10 shows the change sensitivity of the generator group stabilization index of the synchronous generator 4 when the i-th renewable energy power generator 6-i is reduced or stopped per unit amount.

・・・・・ （式１）
ｉ：再生可能エネルギー発電装置６の番号
（i∈I, I:制御対象候補の再エネノードの集合）
ｊ：同期発電機４の番号
Ｕ：不安定となる同期発電機４の群
ΔＰＲＥｉ：再生可能エネルギー発電装置６の減少または停止にかかる単位量
ΔＰＧ：再生可能エネルギー発電装置６の出力電力をΔＰＲＥｉ減少または停止した場合における同期発電機４の出力電力の増加分 (Equation 1) can reproduce the output increment of the synchronous generator 4 that becomes unstable when the renewable energy power generation device 6-i is reduced or stopped per unit amount, and the capacity of the synchronous generator 4 that becomes unstable. The change sensitivity of the stabilizing effect when the output power of the renewable energy power generation device 6-i is reduced or stopped is standardized by the unit amount ΔPREi related to the reduction or stoppage of the energy power generation device 6-i. The stabilization index of the generator group of the synchronous generator 4 is not limited to the output increment of the synchronous generator 4 that becomes unstable when the output power of the renewable energy power generation device 6 is reduced or stopped, for example, the internal phase difference angle. It may be the amount of change (the amount of decrease) or the like.

・・・・ (Formula 1)
i: the number of the renewable energy power generation device 6 (i∈I, I: a set of renewable energy nodes that are control target candidates)
j: Number of synchronous generator 4 U: Group of synchronous generators 4 that become unstable ΔPREi: Unit amount required for reduction or stoppage of renewable energy power generation device 6 ΔPG: Output power of renewable energy power generation device 6 is reduced by ΔPREi Or the increase in the output power of the synchronous generator 4 when stopped

The stabilization index change amount Si is calculated for each assumed accident condition and power flow section classification. When a plurality of tidal flow cross-sections are included in the tidal flow cross-section classification, for example, one representative cross-section is selected from the multiple tidal flow cross-sections included in the tidal flow cross-section classification, and the stabilization index change amount Si is calculated. may For example, the center of gravity is calculated from values such as the voltage, power flow, phase, etc. of the node branch of the power flow calculation result, and the power flow cross section closest to the center of gravity is used as the representative 1 cross section to calculate the stabilization index change amount Si.

In addition, when multiple tidal flow sections are included in the classification of tidal flow sections, two sections with the most different characteristics are selected from the classification of tidal flow sections, and the stabilization index change amount Si is calculated and averaged for each of the two sections. can be For example, select two cross sections where the feature values such as the voltage, power flow, and phase of the node branch in the power flow calculation result are the farthest apart, and calculate and average the stabilization index change amount Si for each of the two cross sections. good too. Alternatively, when the synchronous generators 4 belonging to the power system to be stabilized are classified into a stable group and an unstable group, and only the output of the synchronous machine in the unstable group is used as a feature amount, the distance calculated with the feature amount may be selected, and the stabilization index change amount Si may be calculated and averaged for each of the two cross sections.

・・・・・ （式２） The stabilization index change amount Si is calculated for N nodes of the renewable energy power generation device 6 that are candidates for reduction or suspension.

・・・・ (Formula 2)

(Calculation control by renewable energy group determination unit 12)
The renewable energy group determination unit 12 of the calculation unit 10 selects the plurality of renewable energy power generation devices 6 based on the stabilization index change amount Si, which is the amount of change in the stabilization index calculated by the stabilization index change amount calculation unit 11. Categorize into groups.

Based on FIG. 5, an example of the operation for grouping the renewable energy power generators 6 will be described. In the grouping example shown in FIG. 5, the renewable energy power generators 6 are grouped based on the difference in the stabilization index change amount Si. The renewable energy power generators 6 are grouped based on a preset threshold for the difference in the stabilization index change amount Si.

If sufficient training data for constructing an estimation model can be secured, an estimation model is constructed for each renewable energy power generation device 6 that has not been grouped. If sufficient training data for constructing an estimation model cannot be secured, the renewable energy power generators 6 that have not been grouped are excluded from construction of the estimation model.

As an example, the threshold for the difference in the stabilization index change amount Si is determined by classifying the synchronous generator 4 of the electric power system 9 into a stable group and an unstable group, and determining the internal It is calculated by calculating the electrical output change corresponding to the phase angle change and converting the electrical output change into a stabilization index.

For example, based on the oscillation equation of an unstable generator group, the electrical output change that causes a difference of about 5° in 1 second, which corresponds to 0.5π in the case of a 4-second oscillation period, is converted into a stabilization index, and stabilized. This is used as a threshold for the difference in the index change amount Si. In addition, the grouping method is not limited to the above. For example, securing sufficient teacher data for constructing an estimation model in each group is a constraint condition, and clustering is performed according to the difference in the amount of change in the stabilization index Si. It may be by the method of

In each of the power flow section classifications, the renewable energy group determination unit 12 determines necessary for stabilizing the grouped renewable energy power generation devices 6 with respect to the assumed accident and a plurality of power flow sections within the power flow section classification. Calculate the amount of decrease in output power for each group. The renewable energy group determination unit 12 creates teacher data with power flow calculation results (node voltage, power, branch power flow, etc.) as input and output power reduction amounts for each group of renewable energy power generators 6 as output.

The amount of decrease in the output power of each group of the renewable energy power generation devices 6 required for stabilization is calculated by, for example, accumulating the decrease amounts of the output power in order from the renewable energy power generation device 6 with the highest stabilization index change amount Si. . In addition, the amount of decrease is not limited to the above, and may be calculated by accumulating the amount of decrease for renewable energy included in the same group of renewable energy power generation devices 6, for example. .

(Arithmetic control by estimation model creation unit 13)
The estimation model creation unit 13 of the calculation unit 10 calculates an assumed accident for each group of the plurality of renewable energy power generators 6 grouped by the renewable energy group determination unit 12 for each of the plurality of power flow cross sections of the power system 9. An estimation model is constructed to calculate the amount of decrease in output power required for stabilization at the time of occurrence, and to estimate the amount of decrease for each group of renewable energy power generators 6 based on the node branch information of the cross section of the power flow.

Based on the teaching data created by the renewable energy group determination unit 12, the estimation model creation unit 13 uses statistical models such as regression equations and machine learning for each group of assumed accidents, power flow cross-section classifications, and renewable energy power generation devices 6. Construct an estimation model for the reduction in output power. By inputting the power flow calculation results of the power flow cross section for which the amount of reduction is to be calculated and the assumed accident into the estimation model, the "system configuration (topology) of the power system 9" and the "shutdown state of the synchronous generator 4" can be determined. A corresponding power flow section classification is selected from the degree of similarity, and a reduction amount for each group of renewable energy power generation devices 6 corresponding to the power flow section classification is calculated.

(Arithmetic control by control amount distribution unit 14)
The control amount distribution unit 14 of the calculation unit 10 distributes the amount of decrease for each group of the renewable energy power generation devices 6 estimated by the estimation model creation unit 13 to the renewable energy power generation devices 6 within the group.

Based on the stabilization index change amount Si, the control amount distribution unit 14 selects the group of the renewable energy power generation devices 6 with the highest stabilizing effect due to the decrease or stop of the output power as the maximum stabilizing effect group to be controlled. do. The amount of decrease calculated by the estimation model for the maximum stabilization effect group exceeds the total output value of the renewable energy power generation device 6 in the maximum stabilization effect group, and is necessary for stabilization in a single maximum stabilization effect group If the amount of reduction cannot be secured, the maximum possible reduction amount is assigned to the maximum stabilization effect group, and the surplus amount of the reduction amount is assigned to the group of other renewable energy power generation devices 6, Allocate in descending order of stabilizing effect. The allocation of the surplus amount of reduction is performed by calculating the allocation amount based on the ratio of the required reduction amount of the maximum stabilization effect group and each of the other groups alone.

(Calculation control by control unit 20)
The control unit 20 determines a group of renewable energy power generation devices 6 to be controlled when an accident occurs based on the amount of decrease distributed by the control amount distribution unit 14 of the calculation unit 10, and can reproduce the amount of decrease in output power. Instruct the energy generator 6 .

When an accident occurs, the control unit 20 assigns the amount of decrease for each group of the renewable energy power generation devices 6 calculated by the control amount allocation unit 14 to the groups of the renewable energy power generation devices 6 in descending order of the stabilization effect. Allocate to the nodes of the renewable energy power generation device 6 .

The above is the operation of the power system stabilization system 1 .

[1-3. effect]
(1) According to the present embodiment, the power system stabilization system 1 reduces the supply of power supplied from the plurality of renewable energy power generation devices 6 in the power system 9 that supplies power. Synchronous stability A plurality of renewable energy power generators 6 based on the amount of change in the stabilization index calculated by the stabilization index change amount calculation unit 11 that calculates the amount of change in the stabilization index of and the stabilization index change amount calculation unit 11 Renewable energy group determination unit 12 for classifying into groups, and assumed accidents for each group of a plurality of renewable energy power generation devices 6 classified by the renewable energy group determination unit 12 for each of a plurality of power flow cross sections of the power system 9 An estimation model creation unit 13 that calculates the amount of decrease in output power at the time of occurrence and builds an estimation model for estimating the amount of decrease for each group of renewable energy power generation devices 6 based on the node branch information of the power flow cross section; A control amount distribution unit 14 that distributes the reduction amount for each group of the renewable energy power generation devices 6 estimated by the unit 13 to the renewable energy power generation devices 6 in the group, and the reduction amount distributed by the control amount distribution unit 14 Based on this, the control unit 20 determines a group of renewable energy power generation devices 6 to be controlled when an accident occurs, and instructs the renewable energy power generation devices 6 to decrease the output power, so that the output power is reduced or stopped. It is possible to provide the power system stabilization system 1 that can select a renewable energy power generation device to be used and efficiently ensure the stability of the power system.

In the future, it is expected that the introduction of renewable energy power generators 6 will be promoted, and the electric power system 9 will be operated with a reduced number of operating synchronous generators 4 such as thermal power and hydraulic power. As a result, synchronization stability and voltage stability are degraded, and it may become more difficult to operate the power system 9 stably. A conventional control method for a power system stabilization system that stops a synchronous machine may not be suitable for controlling a power system 9 with a small number of operating synchronous generators 4 .

In the power system 9 in which the number of operating synchronous generators 4 is small, the ratio of the decrease in the output power of the synchronous generator 4 to the output power of the entire power system 9 is high, so inertia, reduction in synchronizing force, and voltage maintenance source This is because the disadvantage of control such as a decrease in the power system appears strongly, and if the control method according to the power system stabilization system according to the prior art is used, it is conceivable that it may fall into an unstable state.

In order to improve this, as an example of conventional technology, there is a control method for reducing or stopping the output power of the renewable energy power generator 6 . However, the control method according to the prior art relies on an on-line precomputation type stabilization system or the like that calculates the control amount by repeating detailed transient stability calculations. The control method according to the prior art has problems such as the fact that it takes time to calculate the control amount.

The power system stabilization system 1 according to the present embodiment can construct an estimation model for estimating the control amount required for stabilization in advance by offline simulation, and can quickly calculate the control amount.

Compared to the synchronous generator 4, the renewable energy power generators 6 are installed in a distributed manner. Therefore, in general, when the renewable energy power generators 6 are to be controlled, the renewable energy power generators 6 scattered at a plurality of locations are used. need to be controlled. When the power system 9 is represented by a power system model expressed by node branches, the case where the renewable energy power generation device 6 is the control target is more than the case where the synchronous generator 4 is the control target. It is thought that it will be necessary to control the power supply of each node.

Therefore, building an estimation model for a single node requires a large amount of training data and cannot be said to be efficient. In order to solve this problem, it is effective to group the renewable energy power generators 6 of multiple nodes and construct an estimation model for this group. In addition, it is desirable that the amount of decrease in output power required for control be minimized.

According to this embodiment, the renewable energy power generators 6 of multiple nodes are grouped based on the similarity of the stabilization effect of the power system 9 to build an estimation model, and the amount of decrease in the output power required for control is minimized. It is possible to determine the renewable energy power generation device 6 and the amount of decrease in the output power that are effective for stabilizing the electric power system 9 while keeping the limit to a minimum.

According to the present embodiment, it is possible to stably control the electric power system 9 in which the number of operating synchronous generators 4 is small, while the shortcomings in control such as reduction in inertia, synchronizing force, and reduction in voltage maintenance sources are improved. It is possible to provide a power system stabilization system 1 that can.

(2) According to the present embodiment, the stabilization index change amount calculation unit 11 calculates a plurality of power flows in the electric power system 9 based on the similarity between the topology of the system configuration and the state when the power supply of the renewable energy power generation device 6 is stopped. The cross section is classified, the amount of change in the stabilization index for each assumed accident is calculated for the classified power flow cross section, and the renewable energy group determination unit 12 determines the stabilization index for the classified power flow cross section. Based on the amount of change, a plurality of renewable energy power generation devices 6 are grouped, a group of renewable energy power generation devices 6 is determined as a unit for creating an estimation model of the amount of decrease, and the estimation model creation unit 13 classifies Since an estimation model is constructed for each group of renewable energy power generation devices 6 for each accident assumed for the tidal flow cross section, a renewable energy power generation device whose output power is quickly reduced or stopped can be selected and power can be efficiently generated. It is possible to provide the power system stabilization system 1 that can ensure the stability of the system.

The power system stabilization system 1 according to the present embodiment estimates the amount of decrease, which is the amount of control required for stabilization, for each group of renewable energy power generation devices 6 for each assumed accident with respect to the classified power flow cross section. By constructing an estimation model in advance by offline simulation, it is possible to quickly calculate the amount of decrease, which is the amount of control.

(3) According to the present embodiment, the stabilization index change amount calculation unit 11 of the power system stabilization system 1 is configured to The amount of change in the stabilization index of synchronization stability is calculated based on the output.

Renewable energy power generators 6 are classified into groups based on the difference in the amount of change in the stabilization index, and groups of renewable energy power generators 6 that are highly effective in stabilizing the power system 9 are preferentially selected as control targets. Since the amount of decrease in output power is instructed, the amount of decrease in output power in each group of renewable energy power generation devices 6 is suppressed.

(4) According to the present embodiment, the stabilization index change amount calculation unit 11 calculates the similarity of a plurality of power flow cross sections of the electric power system 9, The combination is extracted, and the amount of change in the stabilization index of synchronous stability when the power supply of a predetermined amount from the plurality of renewable energy power generation devices 6 is stopped for the tidal flow cross section included in the combination of tidal flow cross sections is calculated. Furthermore, since it is averaged and used as the amount of change in the stabilization index, it is possible to select a renewable energy power generation device 6 that can reduce or stop the output power, which can efficiently ensure the stability of the power system with respect to the power flow cross section. can.

(5) According to the present embodiment, when it is determined that sufficient teacher data for creating an estimation model exists, the renewable energy group determination unit 12 of the power system stabilization system 1 stabilizes each renewable energy A plurality of renewable energy power generators 6 are classified into groups based on the difference in the amount of change in the index.

Since the renewable energy power generation devices 6 each having a smaller output than the synchronous generator 4 are grouped, a sufficient number of teacher data can be secured, and an estimation model constructed based on the teacher data Calculation of the amount of decrease in the output power required for stabilization of the power system 9 and selection of the renewable energy power generator 6 can be performed quickly.

(6) According to the present embodiment, the renewable energy group determination unit 12 of the power system stabilization system 1 classifies the plurality of synchronous generators 4 in the power system 9 to be stabilized into a stable group and an unstable group. Then, from the fluctuation equation of the synchronous generator 4 classified into the unstable group, the electrical output change amount corresponding to the internal phase angle change amount that causes a significant difference in stability is calculated, and the electrical output change amount is used as a stabilization index. with the value converted to . . As a result, the renewable energy power generators 6 having a similar stabilizing effect on the power system 9 are grouped, so that the estimation error due to the estimation model can be minimized.

(7) According to the present embodiment, the renewable energy group determination unit 12 determines that the difference in the amount of change in the stabilization index from any of the other renewable energy power generators 6 does not fall below the threshold in the grouping based on the threshold. When it is determined that there is sufficient training data to create an estimation model for the power generation device 6, an estimation model is created by grouping the individual renewable energy power generation devices 6 as one group, and sufficient teaching data to create an estimation model. is not determined to exist, it is excluded from the estimation model creation targets, so that the renewable energy power generation device 6 with a high stabilizing effect of the power system 9 and the amount of decrease in the output power are calculated with higher accuracy.

(8) According to the present embodiment, the control amount allocation unit 14 sets the renewable energy power generator 6 having the highest stabilizing effect due to the decrease in power supply as the maximum stabilizing effect group based on the amount of change in the stabilization index. In addition to selecting the group to be subject to power supply suspension, if the amount of reduction required for stabilization cannot be secured only for the maximum stabilization effect group, the maximum reduction amount that can stop the power supply to the maximum stabilization effect group At the same time, the difference between the amount of reduction required for the maximum stabilization effect group calculated based on the estimation model and the maximum possible reduction amount is apportioned to other renewable energy power generation equipment different from the maximum stabilization effect group. Therefore, even if the amount of decrease required for stabilization cannot be secured only by the maximum stabilization effect group, the renewable energy power generation device 6 with a high stabilization effect of the power system 9 and the output power The amount of decrease is calculated and distributed to the renewable energy power generators 6 .

[2. Other embodiments]
While embodiments including variations have been described, these embodiments are provided by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, as well as the scope of the invention described in the claims and equivalents thereof. Below is an example.

(1) In the above embodiment, the power system 9 has the synchronous generators 4-1, 4-2, 4-3 and the renewable energy generators 6-1, 6-2. The number and system configuration of the synchronous generator 4 and the renewable energy power generator 6 are not limited to this. The power system 9 may have any number of synchronous generators 4 and renewable energy generators 6 . Also, the power system 9 may have any system configuration.

1 Power system stabilization system 2, 2-1, 2-2 Transmission line 3, 3-1, 3-2, 3-3 Transformer 4, 4-1, 4-2 , 4-3... Synchronous generators 5, 5-1, 5-2, 5-3... Circuit breakers 6, 6-1, 6-2... Renewable energy generators 7, 7-1 , 7-2... accident detection devices 8, 8-1, 8-2, 8-3, 8-4, 8-5, 8-6, 8-7, 8-8, 8-9...
Information collecting device 9... Power system 10... Calculation unit 11... Stabilization index change amount calculation unit 12... Renewable energy group determination unit 13... Estimation model creation unit 14... Control amount distribution Part 20... Control part

Claims (8)

a stabilization index change amount calculation unit that calculates the amount of change in a stabilization index of synchronization stability when the supply of power supplied from a plurality of renewable energy power generation devices in a power system that supplies power is reduced;
a renewable energy group determination unit that classifies the plurality of renewable energy power generation devices into groups based on the amount of change in the stabilization index calculated by the amount of change in stabilization index calculation unit;
Output power required for stabilization at the occurrence of an assumed accident for each group of the plurality of renewable energy power generation devices classified by the renewable energy group determination unit for each of the plurality of power flow cross sections of the power system. an estimation model creation unit that calculates the amount of decrease and constructs an estimation model of the amount of decrease for each of the groups of the renewable energy power generation devices based on the node branch information of the power flow cross section;
a control amount distribution unit that distributes the decrease amount for each group of the renewable energy power generation devices calculated by the estimation model generation unit to the renewable energy power generation devices in the group;
determining the group of the renewable energy power generation devices to be controlled when an accident occurs based on the reduction amount distributed by the control amount distribution unit, and instructing the renewable energy power generation device of the reduction amount of the output power; a control unit;
Stabilization system with The stabilization index change amount calculation unit classifies the plurality of power flow cross sections of the power system based on the similarity between the topology of the system configuration and the outage state of the synchronous generator, and for the classified power flow cross sections, calculating the amount of change in the stabilization index for each assumed accident;
The renewable energy group determination unit classifies the plurality of renewable energy power generation devices based on the amount of change in the stabilization index for the classified power flow cross section, and creates an estimation model of the reduction amount. determining the group of the renewable energy power plants that are
The estimation model creation unit builds the estimation model for each group of the renewable energy power generation devices for each accident assumed for the classified power flow cross section.
2. The stabilization system of claim 1. The stabilization index change amount calculation unit calculates the amount of change in the stabilization index of synchronous stability based on a change in the output of a synchronous generator with an unstable tendency that changes due to the stoppage of power supply to the renewable energy power generation device. calculate,
3. Stabilization system according to claim 1 or 2. The stabilization index change amount calculation unit calculates the similarity of the plurality of power flow cross sections of the electric power system, extracts a combination of the power flow cross sections in which the difference in the similarity is greater than a predetermined value, and calculates the power flow. calculating the amount of change in the stabilization index of synchronous stability when a predetermined amount of power supply from the plurality of renewable energy power generation devices is stopped for the tidal flow cross sections included in the combination of cross sections; averaged as the amount of change in the stabilization index;
4. Stabilization system according to claim 2 or 3. When it is determined that sufficient teacher data for creating the estimation model exists, the renewable energy group determination unit selects the plurality of renewable energy groups based on the difference in the amount of change in the stabilization index between each renewable energy. Categorize the energy generators into groups ,
The estimation model creation unit creates the estimation model based on the teacher data .
5. A stabilization system according to any one of claims 1-4. The renewable energy group determination unit classifies a plurality of synchronous generators in the power system to be stabilized into a stable group and an unstable group, and from the swing equation of the synchronous generators classified into the unstable group, An amount of change in electric output corresponding to an amount of change in internal phase angle that causes a significant difference in stability is calculated, and a value obtained by converting the amount of change in electric output to the stabilization index is used as a threshold value, and the electric power of the renewable energy power generation device Classifying the renewable energy power generation devices for which the difference in the amount of change in the stabilization index is equal to or less than the threshold when the supply is stopped, into the same group;
5. A stabilization system according to any one of claims 1-4. If it is determined that there is sufficient training data to create the estimation model,
In the classification by the threshold, the renewable energy group determination unit separates the renewable energy power generation device for which the difference in the amount of change in the stabilization index from any other renewable energy power generation device is equal to or less than the threshold. Classified into one group as the renewable energy power generation device,
The estimation model creation unit creates the estimation model based on the teacher data,
If it is not determined that there is sufficient training data to create the estimation model,
The renewable energy group determination unit does not group the renewable energy power generation device for which the difference in the amount of change in the stabilization index is not equal to or less than the threshold value with any other renewable energy power generation device,
The estimation model creation unit creates the estimation model excluding the renewable energy power generation devices that are not grouped .
7. The stabilization system of claim 6. The control amount distribution unit selects the renewable energy power generation device having the highest stabilizing effect due to the decrease in power supply as a group with the greatest stabilizing effect based on the amount of change in the stabilizing index, and selects the power supply stop target. And, if the amount of reduction required for stabilization cannot be secured only by the maximum stabilization effect group, the maximum amount of reduction that can stop the power supply is assigned to the maximum stabilization effect group, and the estimation model The difference between the amount of reduction required for the maximum stabilizing effect group and the maximum possible amount of reduction, which is calculated based on distributed by
8. A stabilization system according to any one of claims 1-7.

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