Power system adjustment capability management system and power system adjustment capability management method

Abstract

To ensure the power supply adjustment capability to respond appropriately on a node-by-node basis to frequency fluctuations on a node-by-node basis.SOLUTION: A power system adjustment power management system 100 includes a frequency fluctuation index calculation unit 102 that calculates a frequency fluctuation index that represents a frequency fluctuation within a predetermined time at a point connected to each generator in the power system in response to a fault disturbance, a frequency fluctuation index constraint determination unit 103 that compares the frequency fluctuation index of the power system with a threshold value and determines whether the frequency fluctuation index is within an appropriate range or not, and an output response amount increment calculation unit 104 that calculates a change sensitivity of the frequency fluctuation index to an output response amount when the frequency fluctuation index is not within the appropriate range, and calculates an increment in the output response amount at the point on the basis of the change sensitivity of the calculated frequency fluctuation index.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a power system regulation power management system and a power system regulation power management method for maintaining the stability of a power system.

Background Art

[0002] The frequency of a power system is maintained by controlling the power generation and demand to match each other at all times. When the balance between power generation and demand cannot be maintained, for example, due to the stoppage of a generator or demand, the frequency fluctuates. When the amount of frequency fluctuation exceeds a certain level, a protection function is activated to disconnect the generator or demand (equivalent to the load) from the power system by a protection relay, which may lead to a large-scale power outage. In order to avoid such a situation, it is necessary to quickly perform control such as changing the power generation output or interrupting the demand in order to maintain the balance between power generation and demand (hereinafter also referred to as "supply-demand balance").

[0003] As an index representing the magnitude (rate of change) of the frequency fluctuation per unit time when a supply-demand imbalance occurs, the rate of change of frequency (RoCoF) is used. Also, as an index representing the maximum value of the frequency fluctuation, the frequency maximum deviation (Nadir) is used.

[0004] In recent years, the proportion of inverter-based resources (IBR), which are renewable energy power sources connected to the power system via inverters, in the power system power supply configuration has been increasing. As the proportion of thermal power generation, which is a synchronous machine power source, in the power supply configuration decreases, there is concern that the output response amount for maintaining the supply-demand balance, such as the inertia supplied by conventional synchronous generators and the primary regulation power by governor-free operation, will be insufficient.

[0005] Fig. 1 shows an example of the frequency fluctuation of a general power system. The horizontal axis in the figure indicates time, and the vertical axis indicates frequency. In Fig. 1, RoCoF is shown as the rate of change of frequency from the rated frequency f0 at the time t0 when a large-scale power source stops, and Nadir is shown as the difference (amount of decrease) between the value when the frequency drops most after the large-scale power source stops and the rated frequency f0.

[0006] In Fig. 1, the frequency fluctuation when the inertia / primary regulation force is relatively large is shown by a solid line, and the frequency fluctuation when the inertia / primary regulation force is relatively small is shown by a dashed-dotted line. Generally, when the inertia is insufficient, the frequency is likely to fluctuate when there is an imbalance between power supply and demand, so RoCoF and Nadir increase. When the primary regulation force is insufficient, the speed of changing the power generation output to match the power of demand and generation after the occurrence of the power supply-demand imbalance becomes small, so Nadir increases.

[0007] When the inertia and primary regulation force are insufficient, RoCoF becomes a problem, and the protection device of the inverter-type power source for RoCoF operates, causing the inverter-type power source to trip, or Nadir becomes large. In Fig. 1, an example where the inverter-type power source trips when the frequency drops below the lower limit frequency f lower is shown by a two-dot chain line. The occurrence of such an event further causes power sources to drop out, and it becomes difficult to maintain the power supply-demand balance of the power system due to the chain tripping of power sources, which may lead to a large-scale power outage.

[0008] RoCoF and Nadir generally do not suppress frequency fluctuations by changing the control method in the power system after the start of frequency fluctuations. RoCoF and Nadir ensure and suppress the output response amount so that the frequency fluctuation during an actual accident falls within a stable range according to the amount of inertia in the power system secured in advance and the setting value of the control for the primary regulation force supply preset in the power source.

[0009] In order to maintain the stability of the power system, it is an issue to ensure an output response amount that can suppress the RoCoF and Nadir of the frequency fluctuation index of the power system within an appropriate range. In addition, in order to avoid an increase in the cost of pre-ensuring the inertia and primary regulation force of the power source for responding to the cascading disconnection of inverter-type power sources and system accidents, it is important to ensure an output response amount with little excess or deficiency in suppressing RoCoF and Nadir.

[0010] The frequency of the power system is often regarded as having the same value within one system area. However, when paying attention to the fluctuation phenomenon after power source dropout, a slight difference occurs for each region according to the frequency of each synchronous power source and the electrical circuit positional relationship between the target point and the synchronous power source group. Therefore, regional differences occur in RoCoF and Nadir for each point in the power system. For this reason, in order to prevent the power source from being disconnected from the power system, it is important to operate the power system so that the frequency fluctuations at the point where each power source is connected or in its vicinity (hereinafter collectively referred to as "node") are kept within an appropriate range.

[0011] Patent Document 1 discloses "a method for grasping the inertia of a power system including an inverter-type power source having a simulated inertia function for adjusting the electrical output according to the fluctuations of the power system. The inertia grasping method executed using a computer sets the accident conditions of an assumed accident in the power system, estimates the change amount of the inertia of the inverter-type power source during the assumed accident, estimates the inertia within a partial system area set in the power system, and obtains the change amount of the inertia of the inverter-type power source, or the inertia amount or power control change amount within the partial system area."

Prior Art Documents

Patent Documents

[0012]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0013] However, in the method described in Patent Document 1, the increment of virtual inertia is not calculated based on the control amount necessary for the optimization of RoCoF and Nadir, which are indicators of frequency stability, so that the values of RoCoF and Nadir at each point in the power system do not exceed the appropriate range.

[0014] Thus, in the prior art, for frequency fluctuations in terms of nodes, the amount of inertia and primary regulation force necessary to satisfy the constraints of RoCoF and Nadir in terms of nodes are not planned. Therefore, there has been a concern that when the procurement of output response amounts related to inertia response and primary regulation force response is insufficient, power system destabilization or an increase in procurement costs due to over-securing may occur.

[0015] The present invention has been made in view of the above situation, and at least ensures an adjustment force of a power source that appropriately responds in terms of nodes to frequency fluctuations in terms of nodes.

Means for Solving the Problems

[0016] In order to solve the above problems, a regulation force management system for a power system according to one aspect of the present invention includes a frequency fluctuation index calculation unit that calculates a frequency fluctuation index representing frequency fluctuations within a predetermined time at a point connected to each generator of the power system in response to an accident disturbance, a frequency fluctuation index constraint determination unit that compares the frequency fluctuation index of the power system with a threshold value to determine whether the frequency fluctuation index is within an appropriate range, and an output response amount increment calculation unit that, when the frequency fluctuation index is not within the appropriate range, calculates the change sensitivity of the frequency fluctuation index with respect to the output response amount and calculates an increment of the output response amount at the point based on the calculated change sensitivity of the frequency fluctuation index.

Effects of the Invention

[0017] According to at least one aspect of the present invention, when the frequency fluctuation index is not within the appropriate range, an increment of the output response amount at the point is calculated based on the change sensitivity of the frequency fluctuation index with respect to the output response amount. Thereby, it is possible to ensure an adjustment force of a power source that appropriately responds in terms of nodes to frequency fluctuations in terms of nodes. Problems, configurations, and effects other than those described above will be clarified by the following description of the embodiments.

Brief Description of the Drawings

[0018]

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Modes for Carrying Out the Invention

[0019] Hereinafter, with reference to the accompanying drawings, examples of embodiments for implementing the present invention (hereinafter referred to as "embodiments") will be described. In this specification and the accompanying drawings, the same reference numerals are given to the same or similar components, and redundant descriptions may be omitted, or only descriptions centered on the differences may be made. The number of each component may be singular or plural unless otherwise specified.

[0020] In the following examples, various information is described in a table format, but the various information may be in a data format other than the table format. Also, for example, various designations such as "XX information", "XX table", "XX list", "XX list", etc. are interchangeable. Also, when explaining identification information, expressions such as "identification information", "name", "ID", etc. are used, but these are interchangeable.

[0021] <One Embodiment> The configuration and operation of a regulation power management system for a power system according to an embodiment of the present invention will be described. FIG. 2 shows an example of the configuration of a regulation power management system 100 for a power system according to this embodiment. The regulation power management system 100 for a power system includes an output response amount initial distribution calculation unit 101, a frequency fluctuation index calculation unit 102, a node frequency fluctuation index constraint determination unit 103, an output response amount increment calculation unit 104, an output unit 110, a display unit 120, and a communication unit 130.

[0022] The regulation power management system 100 for a power system is a system that manages the regulation power of a power system including a power source that adjusts output power according to the frequency fluctuation of the power system and / or an inverter-type power source having a simulated inertia function. The power system regulation power management system 100 estimates the frequency fluctuations within a predetermined time at the points connected to each generator in response to an accident disturbance, compares the frequency fluctuation indicators (rate of change of frequency and / or maximum deviation of frequency) at each bus of the power system with a threshold value, and determines whether it is within an appropriate range. When the rate of change of frequency and the maximum deviation of frequency are not within the appropriate range, the change sensitivity of the frequency fluctuation indicator with respect to the output response amount is calculated. Then, based on the estimated change sensitivity, the increment of the output response amount (inertia and / or primary regulation power) of the generator at each point is calculated, thereby generating the output response amount increment data D5. The inertia of the generator includes the inertia of the synchronous generator and / or the virtual inertia of the inverter-type power source.

[0023] Thereby, the power system regulation power management system 100 can maintain the frequency stability during an accident in a power system with an increased renewable energy power source, and the system operator can obtain a system stabilization effect. In addition, it is possible to reduce the excessive securing of the output response amount (regulation power) in preparation for the stability of the frequency, and reduce the cost associated therewith.

[0024] The output response amount increment data D5 can be notified to the user of the power system regulation power management system 100, such as the transmission system operator, to determine whether there is a shortage in the output response amount and present the additional required output response amount. Further, the power system regulation power management system 100 may notify the supply-demand adjustment market management system 200 of the output response amount increment data D5 via the communication unit 130. The transmission system operator is, for example, an operator who operates the transmission system among the power systems.

[0025] The supply-demand adjustment market management system 200 is a system for managing a market for buying and selling power adjustment power. For example, for a certain future specified period, regarding the power grid, the operator of a power source registers that it can provide inertia / primary adjustment power of a certain magnitude, and the grid operator operating the power grid registers the required amount of inertia / primary adjustment power. The operator of a power source is, for example, an electric power company engaged in power generation business, an individual or organization equipped with power generation facilities. The supply-demand adjustment market management system 200 is a system used to procure the inertia and primary adjustment power of power sources necessary for stabilizing the power grid.

[0026] Each power source secures a margin for increasing or decreasing the power generation output for supplying inertia and primary adjustment power based on the contract result. By notifying the output response amount increment data D5 to the supply-demand adjustment market management system 200, the required amount for the required output response amount for the supply-demand adjustment market is notified to the market, and it may be used as an index for a buy bid for the next output response amount market transaction opened before the actual time at the planned time.

[0027] The power source management system 300 is a system for operating and controlling various power source facilities in cooperation with the power grid. In the power source management system 300, the supply capacity of inertia and primary adjustment power can be increased or decreased by changing the number of operating power sources in a power plant, the power generation output of each power source, and the set value of control parameters.

[0028] FIG. 3 is a diagram showing an example of the hardware configuration of the adjustment power management system 100 of the power grid according to the present embodiment. The adjustment power management system 100 of the power grid is composed of a computer system, and includes a display device 11, an input device 12 such as a keyboard and a mouse, a CPU (Central Processing Unit) 13, a RAM (Random Access Memory) 14, a communication I / F (interface) 15, and a storage 16. Each block is connected via a system bus 30 and can communicate with each other by data. The computer system is used as a computer.

[0029] Here, the CPU 13 executes a program for regulating power management of the power system and gives instructions for the image data to be displayed on the display unit 120, and searches for data in various databases, etc. Other processors such as an MPU (Micro Processing Unit) may be used instead of the CPU 13. The RAM 14 is a memory that temporarily stores data necessary for the processing of the regulating power management system 100 of the power system.

[0030] The storage 16 is, for example, an HDD (Hard Disk Drive) or an SSD (Solid State Drive), and is used as a non-transitory recording medium. The storage 16 stores the program data executed by the CPU 13 and various data used in the regulating power management system 100 of the power system.

[0031] The system model data D10 is data related to the facilities constituting the power system, such as lines (resistance, reactance, shunt capacitance) such as transmission lines and transformers, power sources such as power generation facilities and synchronous condensers. By using this data, power flow calculation, sensitivity coefficient calculation, and frequency stability calculation of the power system can be performed. Using the system model data D10, the frequency fluctuations accompanying an accident in the power system can be grasped by simulation.

[0032] The power supply equipment data D11 includes the equipment configuration and electrical characteristics of synchronous generators or synchronous condensers (connected nodes, capacity, transient reactance, inertia, control model, number of units in the power plant, etc.) and inverter-type power sources (connected nodes, capacity, control model, etc.). The information of the inverter-type power source includes connected nodes, control configuration and control parameters, FRT characteristics (operation continuation availability, active power output pattern), etc.

[0033] The virtual inertia control type inverter power supply is a power supply that can have virtual inertia (equivalent to virtual inertia) that simulates the same characteristics as the inertia of a synchronous generator by controlling the inverter for connection to the power grid. Based on the control characteristics and capacity of the inverter, the equipment upper limit of the virtual inertia that can be simulated is determined, and virtual inertia that can be set in the inverter power supply is given within the range up to the upper limit. However, the virtual inertia that can be supplied is limited by the insufficient available capacity of the inverter corresponding to the power generation output of the inverter power supply. For this reason, when the power generation plan of the power supply has already been determined, the upper limit of the virtual inertia that can be supplied from the inverter power supply is reduced according to the planned value of the generated power. Also, the power supply equipment data D11 may include the value of the cost (procurement cost) when providing the output response amount, or a cost curve showing the relationship between the output response amount and the cost. Information regarding these costs can be obtained, for example, from the supply-demand adjustment market management system 200.

[0034] The committed output response amount data D12 is data on the output response amounts of inertia and primary frequency regulation power registered in the supply-demand adjustment market management system 200 and the like for power supply equipment. It is data provided to the regulation power management system 100 of the power grid as the amount already secured as the output response amount in a long-term plan or the like. Note that the committed output response amount data D12 may include data on the output response amounts of inertia and primary frequency regulation power of each power supply in the power grid managed by another grid operator adjacent (connected) to the power grid to be managed.

[0035] The assumed supply-demand scenario data D13 is data on estimated values of the power demand and the generated power of power supplies for which the power demand and the generated power during the planned period in the regulation power management system 100 of the power grid can be estimated. The estimated value of the power demand is, for example, data on the demand value of the power demand model obtained by aggregating the demand below the transformer in the grid model data D10. The estimated power generation amount is, for example, data on the predicted power generation amounts of solar power generation and wind power generation, which are natural fluctuation energy sources. As the estimated power generation amount to be used, for example, is the estimated value in a severe assumption situation where the ratio of renewable energy to the power supply configuration is the highest. Also, the assumed supply-demand scenario data D13 may include estimated values for a plurality of scenarios regarding combinations of cases where demand and power generation amount are large or small.

[0036] Note that the power supply facility data D11 and the committed output response amount data D12 of the input data may be acquired from the supply-demand adjustment market management system 200 and the power supply management system 300 via the communication I / F15.

[0037] The assumed accident data D14 is data on typical severe accident patterns that are assumed to occur in the power system in order to calculate, by simulation, the frequency fluctuations that can occur in the power system. When evaluating frequency stability, for example, accidents in which a plurality of large power sources drop out from the power system due to earthquakes, lightning, etc. are assumed. For example, the accident pattern can be expressed as a combination of one or two power sources that drop out.

[0038] The frequency fluctuation index threshold data D3 is a threshold regarding RoCoF and Nadir of the frequency fluctuation index at each point (node) of the power system. For example, for RoCoF, it is shown as a value such as 2 Hz / sec or less, and for Nadir, in a power system with a reference frequency value of 60 Hz, it is 2 Hz. The threshold of the node frequency fluctuation index may be a different value for each determination point. For example, by appropriately setting the threshold for each point such as a generator, a confluence point of power lines from a plurality of generators, and a connection point to a substation, it contributes to the calculation of an appropriate output response amount increment.

[0039] These input data (system model data D10, power supply facility data D11, committed output response amount data D12, assumed supply-demand scenario data D13, assumed accident data D14, and frequency fluctuation index threshold data D3) are stored in the RAM14 or the storage 16 in FIG. 3.

[0040] In the regulating power management system 100 of the power system, based on these input data, the CPU 13 generates necessary image data and displays it on the display device 11 (for example, a display screen).

[0041] Note that the output response amount increment data D5 is data representing the inertia amount to be supplied from the power source and the output response amount of the primary regulating power so that the frequency fluctuation index of the power system falls within a specified range, which is calculated by the processing algorithm shown in FIG. 8 described later. The output response amount increment is an amount that requests an increase in the output response amount due to inertia and primary regulating power necessary for frequency stability for the target node to which the output response amount is provided. It can also be said that the output response amount increment is an increment with respect to the initial allocation of the output response amount calculated by the output response amount initial allocation calculation unit 101. For example, the inertia amount can be expressed in terms of (unit: [sec]) at the target node, and the primary regulating power can be expressed in terms of the magnitude of the power that can change the output per 10 seconds (unit: [MW / 10sec]).

[0042] The output response amount initial allocation data D1, the node frequency fluctuation index data D2, and the node frequency fluctuation index constraint determination result data D4 will be described later.

[0043] [Overall Processing in the Regulating Power Management System of the Power System] Next, the overall processing in the regulating power management system 100 of the power system according to the present embodiment will be described with reference to FIG. 4. FIG. 4 is a flowchart showing an example of the overall processing in the regulating power management system 100 of the power system. A series of processing in FIG. 4 is started when the system operator instructs the regulating power management system 100 through the input device 12.

[0044] In step S1 of FIG. 4, the output response amount initial distribution calculation unit 101 calculates the inertia / frequency response amount distribution. In step S2, the frequency fluctuation index calculation unit 102 calculates the frequency fluctuation index. In step S3, the node frequency fluctuation index constraint determination unit 103 determines whether the node frequency characteristics constraints are satisfied. In step S4, based on the determination result of step S3, the output response amount increment calculation unit 104 calculates the output response amount increment data D5. Then, in step S5, the output unit 110 outputs the output response amount increment data D5 and causes it to be displayed on the display unit 120.

[0045] [Processing of Output Response Amount Initial Distribution Calculation Unit] Next, the processing by the output response amount initial distribution calculation unit 101 of the power system regulation power management system 100 will be described with reference to FIG. 5. FIG. 5 is a diagram showing a flowchart illustrating an example of the processing algorithm of the output response amount initial distribution calculation unit 101. The output response amount initial distribution calculation unit 101 calculates the output response amount initial distribution. The output response amount initial distribution represents how much output response amount each power source supplies to the target node from the current supply-demand balance without considering the constraints of the node frequency fluctuation index.

[0046] First, in step S11, the output response amount initial distribution calculation unit 101 acquires information related to the power system, such as the system model data D10, the power source equipment data D11, the assumed supply-demand scenario data D13, and the committed output response amount data D12.

[0047] Next, in step S12, the output response amount initial distribution calculation unit 101 reflects the assumed supply-demand scenario data D13 in the given system model data D10.

[0048] Next, in step S13, the output response amount initial distribution calculation unit 101 determines whether there is a power source having a committed output response amount in the committed output response amount data D12. If the corresponding power source exists (YES determination in step S13), the output response amount initial distribution calculation unit 101 proceeds to step S14. If the corresponding power source does not exist (NO determination in step S13), the output response amount initial distribution calculation unit 101 proceeds to step S15.

[0049] In step S14, for the committed power source, the output response amount initial distribution calculation unit 101 sets it as a starting power source on the system model assuming that the power source is operating in the assumed supply-demand scenario. Then, the output response amount initial distribution calculation unit 101 sets the equipment conditions (number of starting units, capacity) and the output response amount of the power source on the system model, and corrects the upper limit value and the lower limit value of the power generation output of the power source to ensure a margin for the output response.

[0050] After the NO determination in step S13 or the process in step S14, in step S15, the output response amount initial distribution calculation unit 101 calculates the power generation amount and the power flow of each power source to achieve the supply-demand balance in the steady state in the assumed supply-demand scenario. For example, by solving the generator start-stop planning problem under the network power flow and supply-demand balance constraints of the power system, the number of generators and the power generation output sufficient to satisfy the supply-demand balance constraints are obtained.

[0051] Next, in step S16, the output response amount initial distribution calculation unit 101 calculates the available response amount (the upper limit of the output response amount) supplied from each power source for the power sources that are not committed power sources among the power sources in the assumed power flow state, and calculates the initial distribution of the output response amount of each power source. When calculating the inertia and the primary adjustment force for each power source, the output response amount initial distribution calculation unit 101 calculates, for example, based on the power generation output in the assumed supply-demand scenario among the power sources capable of supplying the output response amount.

[0052] Specifically, for a synchronous generator, the initial output response amount distribution calculation unit 101 may supply, for example, the minimum governor free width of the grid connection requirement as the power source capable of supplying the primary regulation power. Further, for an inverter type power source, the initial output response amount distribution calculation unit 101 may, for example, set the pseudo inertia and the primary regulation power to zero, or may calculate them as supplying the specified minimum values.

[0053] Next, in step S17, the initial output response amount distribution calculation unit 101 stores the initial output response amount distribution data D1 in the storage 16 and ends the process.

[0054] [Processing of the frequency fluctuation index calculation unit] Next, the processing by the frequency fluctuation index calculation unit 102 of the power system regulation power management system 100 will be described with reference to FIG. 6. FIG. 6 is a diagram showing a flowchart illustrating an example of the processing algorithm of the frequency fluctuation index calculation unit 102.

[0055] First, in step S21, the frequency fluctuation index calculation unit 102 acquires information on the power system used for the frequency control simulation. Here, as the information on the power system used for the frequency control simulation, the system model data D10, the power source equipment data D11, the assumed supply and demand scenario data D13, and the initial output response amount distribution data D1 are acquired.

[0056] Next, in step S22, the frequency fluctuation index calculation unit 102 reflects the parameters of the power source based on the initial output response amount distribution data D1 in the system model data D10 in the frequency control simulation.

[0057] Next, in step S23, the frequency fluctuation index calculation unit 102 acquires the assumed accident data D14.

[0058] Next, in step S24, the frequency fluctuation index calculation unit 102 selects an unselected assumed accident from among the candidates of the assumed accident data D14.

[0059] Next, in step S25, the frequency fluctuation index calculation unit 102 calculates an estimated value of the frequency fluctuation index at the time of the selected assumed accident. In the calculation, for example, time series data of the frequency may be calculated by simulation of time series analysis of the power system using the system model data D10, or RoCoF or Nadir may be estimated using a differential equation related to the frequency and a power circuit equation. Since generally used mathematical formulas can be applied to these differential equations and power circuit equations, detailed descriptions thereof are omitted.

[0060] Next, in step S26, the frequency fluctuation index calculation unit 102 determines whether the estimated values of the frequency fluctuation index have been calculated for all the assumed accidents. If the frequency fluctuation index calculation unit 102 has calculated them (YES determination in step S26), it proceeds to step S27, and if not (NO determination in step S26), it returns to step S24.

[0061] Next, in step S27, the frequency fluctuation index calculation unit 102 stores the estimated value of the frequency fluctuation index in the storage 16 and ends the process.

[0062] Note that if the adjustment power required for the target power system can be obtained as a result, the frequency fluctuation index calculation unit 102 may calculate only RoCoF as the frequency fluctuation index. In this case, the node frequency fluctuation index constraint determination unit 103 described later compares only RoCoF with the threshold value to determine whether the RoCoF is within the appropriate range. Thereby, compared with the case of calculating both RoCoF and Nadir, the same effect can be obtained while reducing the processing load of the power system adjustment power management system 100.

[0063] [Processing of Node Frequency Fluctuation Index Constraint Determination Unit] Next, the processing by the node frequency fluctuation index constraint determination unit 103 (an example of a frequency fluctuation index constraint determination unit) of the power system adjustment power management system 100 will be described with reference to FIG. 7. FIG. 7 is a diagram showing a flowchart illustrating an example of the processing algorithm of the node frequency fluctuation index constraint determination unit 103.

[0064] First, in step S31, the node frequency fluctuation index constraint determination unit 103 reads the frequency fluctuation index threshold data D3.

[0065] Next, in step S32, the node frequency fluctuation index constraint determination unit 103 selects an unselected determination target node.

[0066] In step S33, the node frequency fluctuation index constraint determination unit 103 compares with the threshold of the node frequency fluctuation index and determines whether there is a deviation in the frequency fluctuation index.

[0067] In step S34, the node frequency fluctuation index constraint determination unit 103 determines whether the presence or absence of deviation has been determined for all nodes. If the node frequency fluctuation index constraint determination unit 103 has determined (YES determination in step S34), it proceeds to step S35, and if it has not been determined (NO determination in step S34), it returns to step S32.

[0068] In step S35, the node frequency fluctuation index constraint determination unit 103 stores each node frequency fluctuation index constraint determination result data D4 obtained by aggregating the determination results of all nodes in the storage 16 and ends the process.

[0069] [Processing by the output response amount increment calculation unit] Next, the processing by the output response amount increment calculation unit 104 of the power system regulation power management system 100 will be described with reference to FIG. 8. FIG. 8 is a diagram showing a flowchart illustrating an example of the processing algorithm of the output response amount increment calculation unit 104.

[0070] First, in step S41, the output response amount increment calculation unit 104 acquires information on the power system necessary for the output response amount increment calculation process. Here, as information on the power system necessary for the output response amount increment calculation process, system model data D10, power supply equipment data D11, assumed supply-demand scenario data D13, committed output response amount data D12, output response amount initial distribution data D1, node frequency fluctuation index data D2, and frequency fluctuation index threshold data D3 are acquired. Note that the power supply equipment data D11 may include data on the upper limit of the output response amount that can be supplied from the power supply and the cost (procurement cost) required for supplying the output response amount.

[0071] Next, in step S42, the output response amount increment calculation unit 104 acquires parameters related to the output response amount increment calculation. Here, as the parameter, the unit (unit increase width) of the increment of the output response amount in one calculation loop when calculating the increment of the output response amount by iterative calculation using change sensitivity calculation is acquired. As the unit of the increment, for example, a value such as increasing the amount of inertia or primary regulation power supplied from the power supply by 1% each time is set.

[0072] Next, in step S43, the output response amount increment calculation unit 104 calculates the change sensitivity of RoCoF and Nadir with respect to the unit increment of the output response amount at each node. The change sensitivity is obtained from the values of RoCoF and Nadir before and after changing the output response amount (inertia, primary regulation power) by a unit increment. For example, the change sensitivity may be calculated based on the change in the frequency fluctuation index when the output response amount is perturbed in the frequency simulation at the node.

[0073] Next, in step S44, the output response amount increment calculation unit 104 calculates a unit increment of the output response amount such that the difference between the RoCoF and Nadir of the frequency fluctuation index and the threshold value becomes small based on the change sensitivities of RoCoF and Nadir. For example, the unit increment of the output response amount can be calculated by solving an optimization problem of selecting a power source that supplies the output response amount increment so as to minimize a multi-objective function weighted by the amount that reduces the difference between the threshold values of RoCoF and Nadir. It may also be considered to add the cost of supplying the output response amount to the multi-objective function to reduce the cost.

[0074] Next, in step S45, the output response amount increment calculation unit 104 determines whether or not the estimated values of the frequency fluctuation indices of all the nodes included in the target power system are equal to or less than the threshold value. That is, it is determined whether or not the estimated values of the frequency fluctuation indices of all the nodes are within an appropriate range. When the estimated values of the frequency fluctuation indices of all the nodes are equal to or less than the threshold value (YES determination in step S45), the output response amount increment calculation unit 104 proceeds to step S47, and when the estimated values of the frequency fluctuation indices of all the nodes exceed the threshold value (NO determination in step S45), it proceeds to step S46.

[0075] In step S46, the output response amount increment calculation unit 104 updates the required output response amount with the output response amount reflecting the unit increment calculated in step S44. After the process of step S46, it proceeds to step S43.

[0076] On the other hand, in the case of a YES determination in step S45, in step S47, the output response amount increment calculation unit 104 compares the committed output response amount with the required output response amount and calculates the difference as the output response amount increment.

[0077] Next, in step S48, the output response amount increment calculation unit 104 stores the output response amount increment data D5 in the storage 16 and ends the process.

[0078] The output response amount increment data D5 is output to a device (display unit 120) having a display function such as the display device 11 through the output unit 110 (FIG. 2). Thereby, it is possible to transmit to the operator of the power system the increment of the output response amount (inertia and / or primary regulation force) necessary for maintaining the frequency stability index for each point.

[0079] Note that if the adjustment force required for the target power system can be obtained while satisfying the RoCoF and Nadir constraints, the output response amount increment calculation unit 104 may calculate only one of inertia or the primary regulation force as the increment of the output response amount. Thereby, it is possible to obtain a similar effect while reducing the processing load of the adjustment force management system 100 of the power system as compared with the case of calculating the increment of the output response amount in consideration of both inertia and the primary regulation force.

[0080] [Structure of Output Response Amount Increment Data] Here, the structure of the output response amount increment data D5 will be described with reference to FIG. 9. FIG. 9 shows an example of the structure of the output response amount increment data D5. In FIG. 9, an example in which the output response amount increment data D5 is represented in a table format is shown. For the nodes to which the power sources in the power system are connected, the inertia and the primary regulation force as the output response amount that needs to be increased for stabilizing the power system are displayed on a device having a display function such as the display device 11.

[0081] The output response amount increment data D5 has items of a power source connection node, date and time, inertia, and primary regulation force. The power source connection node is information for identifying the node to which the power source in the power system is connected. The increment of the registered output response amount (inertia, primary regulation force) is supplied to the node. The date and time is information indicating the date and time when the increment of the output response amount is secured. Although only an example of the date is shown in FIG. 9, information on the time such as the time zone may be included. The inertia is information indicating the increment of the inertia (sec) as the output response amount supplied to the target node. The primary regulation power is information indicating an increment of the primary regulation power (MW / 10sec) as an output response amount supplied to the target node.

[0082] For example, in the record of the first row of the output response amount increment data D5, the power supply connection node is "N11", the date and time is "202x / 9 / 1", the inertia is "15 (sec)", and the primary regulation power is "100 (MW / 10sec)".

[0083] The power system regulation power management system 100 may notify the related system of the output response amount increment data D5 via the communication I / F15. For example, the output response amount increment data D5 may be used to determine bids for procuring the output response amount that needs to be added by market transactions in the supply-demand adjustment market management system 200.

[0084] When calculating the output response amount increment, as shown on the left side (before aggregation) of FIG. 10, a sub-system 1002 with a plurality of power sources may be aggregated, and an equivalent power source 1003 may be calculated directly below a certain node 1001 as shown on the right side (after aggregation) of FIG. 10. The sub-system 1002 is connected to the main part 1000 of the power system via the node 1001.

[0085] However, based on the electrical distance between the nodes to be aggregated and each power source, it is approximated as a power source with a reduced output response amount that can be supplied to reduce the deviation of the frequency fluctuation index of the nodes. Thereby, while the increased supply amount of the output response amount can be competitively distributed among the power generation business operator group of the aggregated power sources based on market principles or the like with respect to the required output response amount calculated for the nodes to be aggregated, the output response amount required to keep the frequency fluctuation index of the nodes of the power system within a stable range can be calculated.

[0086] As described above, the adjustment power management system for a power system according to the above-described embodiment can ensure the adjustment power (inertia, or inertia and primary adjustment power) of a power source that appropriately responds in terms of nodes to frequency fluctuations in terms of nodes. Thereby, in this embodiment, in a power system with an increased renewable energy power source, the frequency stability during an accident can be maintained, and a system stabilization effect can be provided for the power system operated by the system operator. Further, this embodiment can reduce the excessive securing of inertia and primary adjustment power in preparation for frequency stability, and can reduce the procurement cost therefor.

[0087] Note that the present invention is not limited to the above-described embodiment, and it goes without saying that various other modifications and application examples can be taken without departing from the gist of the invention described in the claims. For example, the above-described embodiment has described the configuration in detail and specifically for the purpose of explaining the present invention clearly, and is not necessarily limited to the one having all the components described. Also, it is possible to add, replace, or delete some of the components of the configuration of the embodiment with other components.

[0088] Also, each of the above-described configurations, functions, processing units, etc. may be realized in hardware by designing part or all of them, for example, by using an integrated circuit. As the hardware, a processor device in a broad sense such as an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit) may be used.

[0089] Also, each component of the adjustment power management system 100 for a power system according to the above-described embodiment may be implemented in any hardware as long as the respective hardware can transmit and receive information to and from each other via a network. Also, the processing performed by a certain processing unit may be realized by one hardware or by distributed processing by a plurality of hardwares.

[0090] Also, in the above-described embodiments, the control lines and information lines show those considered necessary for explanation, and not necessarily all control lines and information lines are shown on the product. In reality, it may be considered that almost all components are interconnected.

Description of Signs

[0091] 100…Adjusting power management system of power grid, 101…Initial distribution calculation unit of output response amount, 102…Frequency fluctuation index calculation unit, 103…Node frequency fluctuation index constraint determination unit, 104…Increment calculation unit of output response amount, 110…Output unit, 120…Display unit, 130…Communication unit, D1…Initial distribution data of output response amount, D2…Frequency fluctuation index threshold data, D3…Node frequency fluctuation index data, D4…Node frequency constraint index constraint determination result data, D5…Increment data of output response amount, D10…System model data, D11…Power supply equipment data, D12…Output response amount data of committed contracts, D13…Assumed supply and demand scenario data, D14…Assumed accident data

Claims

1. A frequency fluctuation index calculation unit calculates a frequency fluctuation index that represents the frequency fluctuation within a predetermined time period at the point connected to each generator in the power system in response to the accident disturbance, A frequency fluctuation index constraint determination unit that compares the frequency fluctuation index of the power system with a threshold and determines whether the frequency fluctuation index is within an appropriate range, The system includes an output response amount increment calculation unit that calculates the sensitivity of the frequency fluctuation index to the output response amount when the frequency fluctuation index is not within the appropriate range, and calculates the increment of the output response amount at the point based on the calculated sensitivity of the frequency fluctuation index. A power grid adjustment and control system.

2. The frequency fluctuation index calculation unit estimates the frequency change rate as the frequency fluctuation index, The frequency fluctuation index constraint determination unit compares the frequency change rate with a threshold value to determine whether the frequency change rate is within an appropriate range. The power adjustment power management system for a power grid according to claim 1.

3. The frequency fluctuation index calculation unit estimates the maximum frequency deviation in addition to the frequency change rate as the frequency fluctuation index. The frequency fluctuation index constraint determination unit compares the frequency change rate and the maximum frequency deviation with their respective thresholds to determine whether the frequency change rate and the maximum frequency deviation are within an appropriate range. The power adjustment power management system for a power grid according to claim 2.

4. The output response amount increment calculation unit calculates the increment of the inertia and / or primary adjustment force of each generator at the point as the increment of the output response amount at the point, based on the sensitivity of the frequency fluctuation index to change. A power system adjustment power management system according to claim 2 or 3.

5. A method for managing the adjustment capacity of a power system using a power system adjustment capacity management system, A process for calculating a frequency fluctuation index that represents the frequency fluctuation within a predetermined time period at each generator in the power system connected to the power system in response to the accident disturbance, A process for determining whether the frequency fluctuation index of the power system is within an appropriate range by comparing it with a threshold, The process includes, when the frequency fluctuation index is not within the appropriate range, calculating the sensitivity of the frequency fluctuation index to the output response amount, and calculating the increment of the output response amount at the point based on the calculated sensitivity of the frequency fluctuation index to the change. A method for managing the adjustment capacity of the power grid.

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