WO2018051684A1

WO2018051684A1 - Microgrid operation device and microgrid operation method

Info

Publication number: WO2018051684A1
Application number: PCT/JP2017/028732
Authority: WO
Inventors: 正剛今林; 渡辺　雅浩; 亮介中村
Original assignee: 株式会社日立製作所
Priority date: 2016-09-13
Filing date: 2017-08-08
Publication date: 2018-03-22
Also published as: JP2019221006A

Abstract

Provided are a microgrid operation device and a microgrid operation method with which a large-scale stoppage of power demand devices and a stoppage of private power generation equipment can be prevented and a transition to independent operation can be performed suitably by curtailing power demand devices in advance. The microgrid operation device 10 is equipped with: a current system status prediction unit 23 that predicts the current microgrid system status on the basis of measurement data; and a control method formulation unit 27 that determines a dropout during independent operation on the basis of a dropout condition that at least includes frequency fluctuations and/or a voltage fluctuations stored for each power demand device 32 in the microgrid system, uses the frequency fluctuations and the voltage fluctuations to select a power demand device to be curtailed so as to increase the usable power, and curtails the selected power demand device before a transition to independent operation.

Description

Microgrid operation apparatus and microgrid operation method

The present invention relates to a microgrid operation apparatus and a microgrid operation method.

In recent years, with the increasing risk of power outages in the power system, there is a growing need to continue supplying power in the area by operating the microgrid independently. Independent operation of the microgrid means that the breaker at the connection point between the microgrid and the power system is opened, and power supply to the microgrid area is continued using the generator in the microgrid as a power supply source. . In general, the microgrid closes the circuit breaker while the power system is in a healthy state. During this time, power consumed by the microgrid is provided by power supplied from an external system and power supplied from a generator in the microgrid. Here, consider a case where the power system suddenly fails. At this time, the microgrid shifts to the independent operation by opening the circuit breaker at the connection point with the power system and shutting off the microgrid area and the commercial system (power system). However, immediately after the transition to independent operation, the frequency and voltage in the microgrid greatly fluctuate due to the loss of power supplied from the external system (commercial system) and the fluctuation of the power used by the power demanding equipment. To do. Due to the fluctuation of the frequency and voltage, there is a problem that the power demand equipment in the microgrid stops, the fluctuation of the voltage and frequency is amplified, and the private power generation equipment stops.

A technique described in Non-Patent Document 1 has been proposed as an example of a technique for reducing fluctuations in frequency and voltage immediately after the transition to independent operation of a microgrid. In Non-Patent Document 1, as a preparation for self-sustaining transition of a microgrid, the generator (in-house power generation equipment) is controlled so that the tidal current with the external system (commercial system) becomes zero, and immediately after self-sustaining transition with a storage battery The technology which compensates the supply and demand balance of is described. By applying this technology, it is possible to reduce the sudden change in the power demand for the generator (in-house power generation facility) in the microgrid, and there is an advantage that the generator does not stop immediately after the microgrid is operated independently.
As a similar technique, a technique disclosed in Patent Document 1 has been proposed. In Patent Document 1, an electromagnetic wave that causes lightning is measured with a distance detector until the distance to the thunder, and when the distance lightning approaches the private power generation facility up to a predetermined distance, the generated power of the private power generation facility is larger than the load power. Among a plurality of loads, one that disconnects from a power system after performing load interruption and independently operates a private power generation facility is disclosed. Further, in Patent Document 1, the self-sustained operation determination device compares the self-generated power of the private power generation facility with the load power when lightning approaches a predetermined distance, and if the self-generated power is smaller than the load power, When the load shutoff command is given and the self-generated power is larger than the load power, the autonomous operation determination device gives the disconnection control command to the disconnection control device, and loads are applied in order from the preset low priority load. It is stated that it will be blocked.

JP 2005-006414 A

However, in the configurations described in Non-Patent Document 1 and Patent Document 1, the determination about the drop-off of the power demand equipment is not performed, and the voltage and / or frequency fluctuates due to the drop-off of the power demand equipment, and further power There is a risk that demand equipment will drop off and private power generation facilities will be shut down.

Accordingly, the present invention provides a microgrid operation apparatus and a microgrid operation method capable of favorably shifting to a self-sustained operation by avoiding a large-scale stoppage of the power demand equipment and a stop of the private power generation facility by suppressing power demand equipment in advance. I will provide a.

In order to solve the above-mentioned problems, a microgrid operation device according to the present invention is a device for transitioning a microgrid from a grid-operated operation to a self-sustained operation with a commercial system without any power failure. A system state prediction unit for predicting the system state of the power supply, and at least a dropout condition during a self-sustaining operation is determined based on a dropout condition including frequency fluctuation and / or voltage fluctuation stored for each power demand device in the grid of the microgrid, A control method formulating unit that selects a power demand device that suppresses the available power using the frequency variation and / or voltage variation, and performs the suppression of the selected power demand device before the transition to the independent operation; It is characterized by providing.
In addition, the microgrid operation method according to the present invention is a method for transitioning the microgrid from a grid-operated operation with a commercial system to a self-sustained operation without a power failure, and predicts the current grid state of the microgrid from measurement data. And determining at least a dropout during a self-sustaining operation based on a dropout condition including frequency fluctuation and / or voltage fluctuation stored for each power demanding device in the grid of the microgrid, and using the frequency fluctuation and / or voltage fluctuation. It is characterized by selecting a power demand device to be suppressed so that usable power becomes large, and performing the suppression of the selected power demand device before the transition to the independent operation.

According to the present invention, a microgrid operation apparatus and a microgrid operation method capable of satisfactorily shifting to a self-sustained operation by avoiding a mass stoppage of power demand equipment and a stop of private power generation facilities by suppressing power demand equipment in advance. Can be provided.
Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

It is a schematic block diagram of the microgrid operation apparatus which concerns on one Example of this invention. It is a functional block diagram of the microgrid operation apparatus shown in FIG. 1, and a block diagram of a microgrid system provided with it. It is a structural example of a microgrid. It is a figure which shows the interconnection operation state of a microgrid, and the independent operation of a microgrid. It is a figure explaining an example of the omission conditions of an electric power demand apparatus. It is a figure which shows the data structure of the electric power demand apparatus drop condition database shown in FIG. It is a figure which shows a micro grid driving | operation possible area | region. It is a figure which shows the processing flow of the control system formulation part which comprises the microgrid operation apparatus shown in FIG. It is a figure which shows the time change of the frequency fluctuation | variation in the microgrid of a comparative example. It is a figure which shows the time change of the frequency fluctuation in a microgrid at the time of using the microgrid operation apparatus which concerns on a present Example. It is a figure which shows the state of the electric power demand apparatus and private power generation equipment which continue an operation | movement in a comparative example and a present Example.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First, a configuration of a microgrid to which a microgrid operation apparatus according to an embodiment of the present invention is applied will be described.
FIG. 3 is a configuration example of a microgrid. As shown in FIG. 3, the microgrid area system 100 includes a private power generation facility 110, a protection device 120 that protects the private power generation facility, a plurality of power demand equipment groups (L001, L002, L003, L004), and a power demand equipment group L001. Protection device 121 for protecting power, protection device 122 for protecting power demand device group L002, protection device 123 for protecting power demand device group L003, protection device 124 for protecting power demand device group L004, commercial system (power system) 200 And a circuit breaker 130 for connecting to or disconnecting from the commercial system (power system) 200 via the connection line 140.
N indicates a node, the node N004 is connected to the power demand equipment group L001, and a protection device 121 that protects the power demand equipment group L001 is disposed between the node N004 and the node N003. The node N006 is connected to the power demand device group L002, and a protection device 122 that protects the power demand device group L002 is disposed between the node N006 and the node N005. In addition, the node N008 is connected to the power demand device group L003, and a protection device 123 that protects the power demand device group L003 is disposed between the node N008 and the node N007. The node N010 is connected to the power demand device group L004, and a protection device 124 that protects the power demand device group L004 is arranged between the node N010 and the node N009. Node N012 is connected to interconnection line 140, and circuit breaker 130 is arranged between nodes N012 and N011. The node N001 is connected to the private power generation facility 110 via a protection device 120 that protects the private power generation facility. In FIG. 3, in order to simplify the description, it is assumed that each of the demand equipment groups (L001, L002, L003, L004) has the same power fluctuation characteristics and stop conditions for voltage and frequency fluctuations. .

FIG. 4 is a diagram showing a connected operation state of the microgrid and an independent operation of the microgrid. As shown in the upper diagram of FIG. 4, when the circuit breaker 130 disposed between the node N011 and the node N012 connected to the interconnection line 140 is closed, the microgrid regional system 100 is a commercial system (power system). ) It is in the state of the interconnection operation that operates in conjunction with 200. There are two power supply sources during the interconnected operation: power purchase from the commercial system (power system) 200 via the interconnecting line 140 and power generation by the private power generation facility 110. On the other hand, as shown in the lower diagram of FIG. 4, when the circuit breaker 130 arranged between the node N011 and the node N012 connected to the interconnection line 140 is open, the microgrid regional system 100 is a commercial system (power The system is in a self-sustaining operation state in which it is operated independently from 200). During the self-sustained operation, it is impossible to purchase power from the commercial system (power system) 200 via the interconnection line 140, so the power supply source is only power generation by the private power generation facility 110.

Here, it is assumed that the commercial system (power system) 200 suddenly fails during a grid operation. When the commercial grid (power grid) 200 is blacked out, the microgrid regional grid 100 opens the circuit breaker 130 and shifts to a self-sustaining operation. When shifting to a self-sustained operation, the voltage and frequency in the microgrid regional system 100 vary greatly. This voltage and frequency variation is caused by the following three factors.
(1) Sudden loss of purchased electricity
(2) Changes in the amount of power used by power demand equipment
(3) Omission of power demand equipment due to voltage and frequency fluctuations In order to eliminate these three factors, in this embodiment, the power demand equipment having the following two features is removed before the commercial grid (power grid) 200 fails. Use suppression methods.
(A) Electric power demand equipment with large fluctuations in power consumption
(B) Electric power demand equipment that easily falls off
By suppressing in advance the power demanding equipment having the above two features (a) and (b), the amount of purchased power is reduced in advance, and the sudden change at the time of transition to the independent operation shown in the above factor (1) The fluctuations in voltage and frequency due to loss of purchased power can be suppressed. In addition, the fluctuation of the power consumption of the power demand equipment shown in the above factor (2) and the further voltage and frequency fluctuations in the microgrid regional system 100 due to the drop of the power demand equipment due to the above factor (3) are suppressed. It becomes possible to do.

For example, when the power demand device group L001 shown in FIG. 3 is a power demand device group that is easy to drop out, and the power demand device group L004 (FIG. 3) is a power demand device group with large fluctuations in the amount of power used, A power demand device to be suppressed is selected from a plurality of power demand devices belonging to the demand device group L001 and the power demand device group L004. In addition, if all the power demand apparatuses which belong to the power demand apparatus group L001 and the power demand apparatus group L004 are suppressed, the fluctuation | variation of the voltage in the microgrid area system | strain 100 and a frequency can be made small, and a power demand apparatus and the private power generation equipment 110 stop. Risk is reduced. However, in this case, the amount of power demanding equipment that can be used is reduced. On the other hand, among the plurality of power demand devices belonging to the power demand device group L001 and the power demand device group L004, if the number of power demand devices to be suppressed is small, the amount of power demand devices that can be used increases, but in the microgrid regional system 100 Voltage and frequency fluctuations increase, and the risk of shutting down the power demand equipment and the private power generation facility 110 increases.

FIG. 1 is a schematic configuration diagram of a microgrid operation apparatus according to an embodiment of the present invention. As shown in FIG. 1, a microgrid operating device 10 includes a display device 11 such as an LCD or an organic EL display, an input device 12 such as a keyboard or a mouse, a CPU 13, a communication device 14, a RAM (Random Access Memory) 15, a power demand. A device characteristic database 16, a power demand device dropout condition database 17, a power demand device restraint condition database 18, a microgrid region system analysis database 19, and a program data storage database 20 are provided, which are interconnected via an internal bus 21. Has been.

Here, the CPU 13 reads out various programs from the program data storage database 20 via the internal bus 21, executes instructions for image data to be displayed, or stores them in various databases described in detail later via the internal bus 21. Search data. RAM (Random Access Memory) 15 is characteristic data of power demand equipment, drop-out condition data of power demand equipment and restraint condition data of power demand equipment, system analysis model data in the microgrid area system 100, determination result of control method, This is a memory for temporarily storing data and the like representing the calculation results of the voltage and frequency waveform after the transition to the independent operation. The CPU 13 generates necessary image data based on these data stored in the RAM 15 and transfers the image data to the display device 11 via the internal bus 21. The display device 11 displays the image data transferred from the CPU 13 on a display screen (not shown).

The power demand equipment characteristic database 16 stores power consumption characteristics by voltage and frequency for each power demand equipment constituting each power demand equipment group (L001 to L004), and power when a certain time width has passed (when a predetermined time has passed). Stores data indicating the actual data of the fluctuation amount.
The power demand equipment drop condition database 17 stores power demand equipment drop conditions due to frequency fluctuation and / or voltage fluctuation in association with the type of power demand equipment and the amount of power used. The power consumption equipment drop-off conditions differ for each power demand equipment depending on the voltage and / or frequency conditions. As an example of the conditions for dropping off the power demand equipment, FIG. 5 shows the operation range for each voltage and frequency of the general-purpose low-voltage three-phase squirrel-cage induction motor. FIG. 5 is described in Non-Patent Document 2. In FIG. 5, for example, when a rated frequency of 60 Hz is used as a reference, 60 Hz is normalized as 1.00. In the region outside the hatched portion, that is, in the boundary region where the frequency (pu) is 0.95 to 1.03 and the voltage (pu) is 0.90 to 1.10, the area is short. If it is time, it is an area where the power demand device may be operated. Further, in the shaded area, that is, in the area where the frequency (pu) is 0.98 to 1.02 and the voltage (pu) is 0.95 to 1.05, it is always This is the area where power demand equipment continues to operate.

The power demand device restraint condition database 18 stores data indicating whether restraint is possible and whether dropout is possible for each power demand device. The data indicating whether or not suppression is possible includes, for example, the time that can be suppressed for the power demand device.
The system analysis database 19 in the microgrid area stores data relating to facilities constituting the power system in the microgrid area system 100 such as lines (resistance, reactance, capacitance to ground) and generators (capacity, transient reactance, etc.). ing. By using these data, it is possible to calculate the power flow of the power system in the microgrid area system 100 and the behavior of the private power generation equipment 110, and to grasp the frequency fluctuation and / or voltage fluctuation at the time of shifting to the independent operation. Can do.
The program data storage database 20 stores a system analysis model creation program PR1, a system calculation program PR2, and a demand device (power demand device) control method determination program PR3. These programs are read and executed by the CPU 13 as needed via the internal bus 21.

FIG. 2 is a functional block diagram of the microgrid operation apparatus shown in FIG. 1 and a configuration diagram of a microgrid system including the functional block diagram. As shown in FIG. 2, the microgrid operation apparatus 10 includes a current system state prediction unit 23, a device demand fluctuation prediction unit 24, an independent time zone system state calculation unit 25, a device dropout determination unit 26, a control method formulation unit 27, power Demand equipment characteristic database 16, power demand equipment dropout condition database 17, power demand equipment restraint condition database 18, system analysis database 19 in microgrid area, and microgrid operable area database 22 are provided. The microgrid operation apparatus 10, the command transmission 31, the power demand device 32, the generator 33, the renewable energy 34, the sensor 35, the circuit breaker 130, and the interconnection 140 constitute a microgrid system. Here, the generator 33 and the renewable energy 34 constitute the private power generation facility 110 shown in FIG. 3 described above. As the renewable energy 34, for example, a solar power generation device, an air volume power generation device, a biomass power generation device, or the like is used. As the generator 33, for example, cogeneration is used.

The current system state prediction unit 23 is based on data measured and collected by the sensor 35, such as the power demand device 32, the generator 33, the active power output of the renewable energy 34, the reactive power output, the voltage at the connection end, and the current. Then, the voltage distribution and power flow state of the current microgrid regional system 100 are obtained. The current system state prediction unit 23 outputs the obtained voltage distribution and power flow state of the current microgrid regional system 100 to the in-self-time-time system state calculation unit 25. The current system state prediction unit 23 is realized, for example, when the CPU 13 illustrated in FIG. 1 reads and executes the system calculation program PR2 stored in the program data storage database 20 via the internal bus 21.

The equipment demand fluctuation prediction unit 24 is stored in the power demand equipment characteristic database 16, after a certain time width based on the actual data of the power fluctuation amount when a certain time width elapses (when a predetermined time elapses) ( Predict power fluctuations for each power demanding device after a further predetermined time elapses, and calculate the power fluctuations for each power demanding device after a certain predicted time span (after a further predetermined time elapses) To the unit 25.

The in-stand-time system state calculation unit 25 stores the power fluctuation for each power demanding device after a further certain time width (after the elapse of a further predetermined time) input from the equipment demand fluctuation prediction unit 24, in the power demanding equipment characteristic database 16. Microgrid area such as voltage (frequency, reactance, ground capacitance) and generator (capacity, transient reactance, etc.) stored in the grid analysis database 19 in the microgrid area, voltage and frequency characteristics for each stored power demand device Based on the data relating to the facilities constituting the power system in the system 100, and the current voltage distribution and power flow state of the microgrid area system 100 input from the current system state prediction unit 23, the voltage at the time of transition to the autonomous operation, The frequency fluctuation is transiently calculated at a unit time interval (in a predetermined cycle). The in-stand-time system state calculation unit 25 outputs the voltage and frequency fluctuations at the time of shifting to the independent operation at every unit time interval (predetermined period) to the device dropout determination unit 26 and the control method formulation unit 27. .

The equipment dropout determination unit 26 stores the voltage and frequency fluctuations at each power demand equipment end and a power demand equipment dropout condition database 17 inputted in units of unit time (predetermined period) inputted from the in-standtime system state calculation unit 25. It is determined whether or not the power demand device is dropped based on the power demand device drop condition due to the frequency fluctuation and / or voltage fluctuation stored in association with the type of power demand equipment and the amount of power used. The data of the power demand device determined to be dropped is output to the in-self-time-time system state calculation unit 25 and is reflected in the above-described processing in the in-self-time-time system state calculation unit 25. That is, the in-self-time-time system state calculation unit 25 sets the power consumption of the power demand device corresponding to the power loss data of the power demand device input from the device loss determination unit 26 to zero, and the voltage and frequency in the next unit time unit. Perform the calculation of the fluctuations. The device dropout determination unit 26 executes processing in parallel with the independence time zone system state calculation unit 25.

The control method formulation unit 27 stores the voltage and frequency fluctuation of each power demanding device at every unit time interval (predetermined period) and the power demanding device suppression condition database 18 input from the in-standtime system state calculation unit 25. Based on the data indicating whether or not each stored power demand device can be suppressed and whether or not it can be dropped, the power demand device to be suppressed before the shift to the independent operation is obtained.

Here, the data structure of the power demand equipment dropout condition database 17 will be described. FIG. 6 is a diagram showing a data structure of the power demand equipment dropout condition database 17 shown in FIG. As shown in FIG. 6, the power demand equipment drop condition database 17 includes a “symbol” column for identifying the power demand equipment group shown in FIG. 3, and a “power demand equipment” indicating the type of power demand equipment belonging to the power demand equipment group. Table of “Type of” column, “Amount of power used” column that indicates the amount of power used by power-demanding devices belonging to the group of power-demanding devices, and column of “Omitment condition” that indicates the dropping conditions of power-demanding devices belonging to the group of power-demanding devices Stored in the format. For example, for the power demand equipment group L001, “L001” in the “symbol” field, “inverter a” in the “type of power demand equipment” field, “0.54 MW” in the “power consumption” field, and In the “dropout condition” column, “−0.30 Hz <Δf <+0.30 Hz” is stored as a possible range (allowable frequency fluctuation range) of the frequency fluctuation Δf that can avoid the dropout during the transition to the independent operation. ing. Here, in order to simplify the description of the power demanding equipment group L001, only the inverter a is described, but actually, the power demanding equipment group L001 includes a plurality of inverters a. The same applies to other power demanding equipment groups.

Further, as shown in FIG. 6, for the power demand equipment group L002, “L002” is displayed in the “symbol” column, “induction motor” is displayed in the “type of power demand equipment” column, and “power consumption” column is displayed. “−0.30 Hz <Δf <+0.18 Hz” is stored in the “0.25 MW” and “dropout condition” columns. For the power demand equipment group L003, “L003” in the “symbol” field, “inverter b” in the “type of power demand equipment” field, “0.70 MW” in the “power consumption” field, and “drop off” In the “condition” column, “−0.42 Hz <Δf <+0.42 Hz” is stored. For the power demand equipment group L004, “L004” in the “symbol” field, “other” in the “type of power demand equipment” field, “0.51 MW” in the “power consumption” field, and “dropout condition” "Do not drop off" is stored in the "" column.

In FIG. 6, as an example of the “dropout condition”, a case where the range (allowable frequency fluctuation range) of the frequency fluctuation Δf that can avoid the dropout during the transition to the independent operation is specified is shown. However, the voltage fluctuation range (allowable voltage fluctuation range) that can avoid the dropout during the transition to the independent operation may be defined as the dropout condition. It is desirable to specify both the allowable frequency fluctuation range and the allowable voltage fluctuation range as the “drop-off condition”, and it is also possible to define only one of the allowable frequency fluctuation range or the allowable voltage fluctuation range. good.

Here, referring back to FIG. 2, the microgrid operable region database 22 stores the voltage and frequency range in which the private power generation facility 110 can continue to operate, and the operating state of the voltage and frequency that can be taken when shifting to the independent operation. . Further, the microgrid operable region database 22 is obtained by the most severe voltage, frequency value, and control method formulation unit 27 at the time of transition to the independent operation obtained by the above-described autonomous state system state calculation unit 25. The power demand equipment to be suppressed before the transition to the independent operation is suppressed, and the most severe voltage and frequency values when the microgrid regional system 100 is controlled are stored. FIG. 7 is a diagram showing a microgrid operable region. In FIG. 7, the frequency is plotted on the horizontal axis and the voltage is plotted on the vertical axis, and the private power generation facility operable region 41 is shown in the shaded region. In the pre-control severest condition 42, that is, when the control by the microgrid operation apparatus 10 is not performed before the transition to the independent operation, the vehicle deviates from the private power generation facility operable region 41. On the other hand, when the control by the microgrid operation apparatus 10 is executed before the transition to the most severe condition 43 after the control, that is, the self-sustained operation, it is shown that it falls within the private power generation facility operable region 41. .

Next, the processing flow of the control method formulation unit 27 constituting the microgrid operation apparatus 10 will be described. FIG. 8 is a diagram showing a processing flow of the control method formulation unit that constitutes the microgrid operation apparatus shown in FIG.
As shown in FIG. 8, in step S <b> 101, the control method formulating unit 27 determines that each power demanding device end at every unit time interval (predetermined period) at the time of shifting to the independent operation from the independent state system state calculation unit 25. Frequency fluctuations and voltage fluctuations are acquired.

In step S102, the control method formulation unit 27 selects a power demand device that is a target to be suppressed before shifting to the independent operation. Here, the power demand device to be controlled is a power demand device having any one of the following four characteristics.
(1) Electricity demand equipment connected to a point with large fluctuations in voltage and frequency
(2) Electricity demand equipment that easily falls off due to voltage fluctuation
(3) Electricity demand equipment that easily falls off due to frequency fluctuations
(4) Power Demand Equipment with Large Fluctuation in Power Use In Step S103, the control method formulation unit 27 determines the power demand equipment combination to be suppressed from the power demand equipment that is the suppression target selected in Step S102. . Here, the determined number N of power demand device combinations to be suppressed is N = 1, 2,... M.
Next, the control method formulation unit 27 sets “1” as the number N of combinations of power demanding devices to be suppressed (step S104), and sends a suppression command transmission 31 (FIG. 2) to the power demanding devices corresponding to the combination. Is output.

After controlling the microgrid area system 100, the in-stand-time in-system system state calculation unit 25 performs the operation for each power demanding device after a certain time width (after the elapse of a further predetermined time) input from the device demand fluctuation prediction unit 24. Power fluctuation, voltage and frequency characteristics for each power demand device stored in the power demand equipment characteristic database 16, lines (resistance, reactance, ground capacitance) and generator (capacity) stored in the microgrid system analysis database 19 , Transient reactance, etc.) based on data relating to facilities constituting the power system in the microgrid area system 100 and the current voltage distribution and power flow state of the microgrid area system 100 input from the current system state prediction unit 23. , Transient voltage and frequency fluctuations at unit time intervals (with a predetermined period) Calculated to. The control method formulation unit 27 acquires frequency fluctuations and voltage fluctuations at each power demanding device end for each unit time interval (predetermined period) after the control of the microgrid regional grid 100 from the independent time zone grid state calculation unit 25 ( Step S105).

In step S106, the control method formulation unit 27 performs frequency fluctuations and voltage fluctuations at each power demanding device end for each unit time interval (predetermined period) after the control of the microgrid regional system 100 acquired in step S105. It is determined whether or not the data (conditions) stored in the power demand equipment restraint condition database 18 indicating the restraint propriety and dropout feasibility for each power demand equipment are violated. In other words, the control method formulation unit 27 determines restrictions on the device suppression condition. As a result of the determination, if the data (conditions) indicating whether or not suppression is possible or not is violated, in step S107, the number N of power demand equipment combinations to be suppressed is “N = N + 1” (increment by 1), and the process returns to step S105. Then, the processing of step S105 and step S106 is executed again. On the other hand, if the result of determination is that there is no violation of the data (conditions) indicating whether suppression is possible and whether it is possible to drop out, the process proceeds to step S108.

In step S108, the control method formulation unit 27 determines whether or not the number N of combinations of power demand devices to be suppressed has reached m. As a result of the determination, if the number N of combinations of power demand devices to be suppressed is less than m, the process proceeds to step S107, and the processes from step S105 to step S108 are executed again as described above. On the other hand, if the number N of combinations of power demand devices to be suppressed reaches m as a result of the determination, the process proceeds to step S109.

In step S109, the control method formulation unit 27 obtains the total amount of power used by the suppressed power demand device, and stores it in a storage unit (not shown) together with the suppressed power demand device. In addition, you may comprise so that the total of the used electric energy of the calculated | required electric power demand apparatus and the suppressed electric power demand apparatus may be stored in the predetermined | prescribed storage area of the microgrid operable area | region database 22. FIG.

In step S110, the control method formulation unit 27 is a self-supporting unit that minimizes the total amount of power consumption of the suppressed power demand devices stored in a predetermined storage area of the storage unit (not shown) or the microgrid operable area database 22. A combination of power demand devices to be suppressed before shifting to operation is determined as a control method of the microgrid regional system 100 at the time of shifting to independent operation.
The processing flow by the control method formulation unit 27 that constitutes the microgrid operation device 10 shown in FIG. 8 minimizes the amount of power demand equipment to be suppressed at the time of transition to independent operation, and the power demand equipment that should be prevented from dropping out. It is possible to create a control system for the microgrid area system 100 that can avoid dropping or stopping the private power generation facility 110.
In addition, as an electric power demand apparatus which can be selected as a suppression object apparatus in the above-mentioned step S102, for example, in the case of home appliances, it is lighting, an air conditioner, etc., and since a refrigerator or the like needs to be constantly operated, the suppression object apparatus Excluded from.
Further, in step S101, the control method formulation unit 27 causes the frequency variation and voltage at each power demanding device end in units of unit time (predetermined cycle) when the system state calculation unit 25 in the independent time zone shifts to the independent operation. Although it is set as the structure which acquires a fluctuation | variation, it is not restricted to this. For example, as a configuration in which the control method formulation unit 27 acquires only the frequency fluctuation of each power demanding device end at every unit time interval (predetermined period) at the time of transition to the independent operation from the independent state time zone system state calculation unit 25. Also good. Instead of this, the control method formulation unit 27 receives only voltage fluctuations at the ends of each power demanding device at unit time intervals (predetermined period) when the system state calculation unit 25 in the independent time zone shifts to the independent operation. It is good also as a structure which acquires.

FIG. 9 is a diagram illustrating a time variation of frequency variation in the microgrid of the comparative example, and FIG. 10 is a diagram illustrating a time variation of frequency variation in the microgrid when the microgrid operation apparatus according to the present embodiment is used. It is. 9 and 10, the microgrid regional system 100 assumes a configuration example of the microgrid shown in FIG. 3 described above. As shown in FIG. 6, in the power demand device dropout condition database 17, the power consumption amount of the power demand device group L001 is 0.54 MW, the power consumption amount of the power demand device group L002 is 0.25 MW, The power consumption of the demand equipment group L003 is 0.70 MW, and the power consumption of the power demand equipment group L004 is 0.51 MW. Accordingly, the total amount of power used by the power demand equipment groups L001 to L004 is 2.00 MW, and 0.40 MW of power is purchased from the commercial system (power system) 200 via the interconnection line 140 to obtain 1.60 MW. Is supplied by the private power generation facility 110.

In FIG. 9, time is plotted on the horizontal axis and frequency variation is plotted on the vertical axis, and the time variation of the frequency variation in the comparative example is shown when shifting to a self-sustained operation without suppressing power demand equipment. As shown in FIG. 9, after the shift to the independent operation, the frequency fluctuation Δf has decreased to −3.0 Hz. The “drop-off condition” as a possible range (allowable frequency fluctuation range) of the frequency fluctuation Δf stored in the power demand equipment drop-out condition database 17 shown in FIG. 6 and capable of avoiding the drop-out during the transition to the independent operation. Out of the range of “−0.30 Hz <Δf <+0.30 Hz” which is the dropout condition of the power demand equipment group L001 and “−0.30 Hz <Δf <+0.18 Hz” which is the dropout condition of the power demand equipment group L002. Therefore, the inverter a belonging to the power demand device group L001 and the induction motor belonging to the power demand device group L002 are missing. Due to the dropout of the inverter a belonging to the power demanding equipment group L001 and the induction motor belonging to the power demanding equipment group L002, the frequency fluctuation increases rapidly, and is 4.2 Hz larger than the reference. Due to this increase in frequency fluctuation, the inverter b belonging to the power demand equipment group L003 falls off because it is outside the range of “−0.42 Hz <Δf <+0.42 Hz” which is the drop condition of the power demand equipment group L003. Yes. Due to the dropout of the inverter b belonging to the power demand equipment group L003, the frequency fluctuation is further increased, and there is a possibility that the private power generation facility 110 stops and the transition to the independent operation fails.

Next, in FIG. 10, the time is plotted on the horizontal axis and the frequency variation is plotted on the vertical axis, and control is performed in advance to stop the inverter a belonging to the power demand equipment group L001, which is an easily demanded power demand equipment, and a transition is made to independent operation. The time change of the frequency fluctuation at the time of using the microgrid operation apparatus 10 which concerns on a present Example at the time of doing is shown. As shown in FIG. 10, the frequency fluctuation is caused by stopping the inverter a belonging to the power demand device group L001 which is a power demand device that is likely to drop out in advance before the shift to the independent operation (suppression of the power demand device). It can be seen that the power demand equipment can be prevented from falling off, and the operation can be shifted to the independent operation.

FIG. 11 is a diagram illustrating a state of the power demanding equipment and the private power generation facility that continue to operate in the above-described comparative example and this example. As shown in FIG. 11, in the comparative example shifted to the independent operation without suppressing the power demanding equipment, the private power generation facility 110 is stopped and the power supply source in the microgrid regional system 100 is lost. As a result, all power demanding devices belonging to the power demanding device groups L001 to L004 become unusable. On the other hand, in the present embodiment, the amount of power used by the inverter a belonging to the power demand device group L001 is determined by controlling the inverter a belonging to the power demand device group L001 in advance and shifting to the independent operation. 0.54 MW is suppressed, and 1.46 MW, which is the total amount of power used by the power demanding devices belonging to the remaining power demanding device groups L002 to L004, is supplied from the private power generation facility 110 that is continuously operated.

As shown in FIG. 10, when the time change of the frequency fluctuation is low and stable after the transition to the self-sustaining operation, the control method formulation unit 27 configuring the microgrid operation apparatus 10 performs the above-described FIG. By executing again the processing flow shown in Fig. 5, it may be configured to reconnect any of the power demanding devices that have been regarded as the devices to be suppressed until the self-sustained operation. In this case, for example, a combination of power demand devices set in advance in step S103 is added and the processing up to step S110 is executed, or the total number of combinations of power demand devices is increased to steps S103 to S110. By executing this process, it is possible to reduce the number of power demand devices that are devices to be suppressed and obtain a power demand device to be reconnected.

As described above, according to the present embodiment, a microgrid operation device capable of avoiding a large-scale stoppage of power demand equipment and a stop of private power generation facilities by suppressing power demand equipment in advance, and making a good transition to independent operation, and It is possible to provide a microgrid operation method.
In addition, according to the present embodiment, the amount of restraint of the power demanding equipment at the time of transition to the self-sustained operation can be minimized, so that the power demanding equipment that should be avoided from falling off or the private power generation facility from being stopped can be avoided. A grid area system control method can be created.

In the present embodiment, the combination of suppression target devices (the combination of power demand devices to be suppressed) in step S103 is determined in the processing flow of the control method formulation unit 27 configuring the microgrid operation apparatus 10 illustrated in FIG. The device selection method is different from that of the first embodiment. Other configurations are the same as those of the above-described first embodiment, and steps other than step S102 and step S103 illustrated in FIG. 8 are the same as those of the first embodiment.

In the above-described first embodiment shown in FIG. 8, the control method formulation unit 27 executes steps S102 and S103. However, in this embodiment, the control method formulation unit 27 executes the next step after executing step S101. Step S103 shown is executed. In step S103, the control method formulation unit 27 determines all possible combinations of control devices as combinations of power demand devices that are to be suppressed. Here, “a combination of all possible control devices” is a combination of all control devices such that the amount of power used by the power demand device is less than the rated output of the private power generation facility. The reason for excluding the combination of control devices that exceed the rated output of the private power generation facility from the combination of power demanding devices that should be controlled is that when the power demand in the microgrid area system 100 exceeds the rated output of the private power generation facility, This is because the balance between supply and demand in the microgrid regional system 100 collapses and the private power generation facilities stop.

As described above, according to the present embodiment, in addition to the effects of the first embodiment, it is possible to optimally determine a combination of suppression devices (a combination of power demand devices). As a result, it is possible to determine a microgrid operation method that maximizes power consumption in subsequent calculations and that can prevent a power failure in the microgrid regional system.

In addition, this invention is not limited to the above-mentioned Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described.

DESCRIPTION OF SYMBOLS 10 ... Micro grid operation apparatus, 11 ... Display apparatus, 12 ... Input device, 13 ... CPU, 14 ... Communication apparatus, 15 ... RAM, 16 ... Electric power demand apparatus characteristic Database, 17 ... Power demand equipment dropout condition database, 18 ... Power demand equipment restraint condition database, 19 ... Microgrid system analysis database, 20 ... Program data storage database, 21 ... Internal bus , 22 ... Microgrid operable region database, 23 ... Current system state prediction unit, 24 ... Equipment demand fluctuation prediction unit, 25 ... Independent time zone system state calculation unit, 26 ... Equipment dropout Judgment part, 27 ... Control method formulation part, 31 ... Command transmission, 32 ... Electric power demand equipment, 33 ... Generator, 34 ... Renewable energy 35 ... sensor, 41 ... operating power generation facility operable region, 42 ... the most severe condition before control, 43 ... the most severe condition after control, 100 ... micro grid area system, 110 ... Private power generation equipment, 120, 121, 122, 123, 124 ... protection device, 130 ... circuit breaker, 140 ... interconnection line, 200 ... commercial system, N ... node, L ...・ Electric power demand equipment group

Claims

This is a device for transitioning the grid from the grid operation to the autonomous operation without any power failure. The current grid status prediction unit predicts the grid status of the current grid from the measurement data. Based on the dropout conditions including frequency fluctuations and / or voltage fluctuations stored for each power demand device in the system, the dropout in the independent operation is determined, and the power that can be used is large by using the frequency fluctuations and / or voltage fluctuations. And a control method formulation unit that selects a power demand device to be suppressed so that the selected power demand device is suppressed before shifting to a self-sustaining operation.
In the microgrid operation device according to claim 1,
A power demand equipment dropout condition database for storing the power demand equipment dropout conditions due to frequency fluctuations and / or voltage fluctuations in association with the type of power demand equipment and the amount of power used;
A microgrid comprising: a self-time-time system state calculation unit that obtains a frequency variation and / or a voltage variation during a self-sustained operation based on at least the current microgrid system state by the current system state prediction unit; Operational device.
In the microgrid operation device according to claim 2,
Frequency fluctuation and / or voltage fluctuation at the time of self-sustained operation determined by the system state calculation unit in the independent time zone, and the power demand equipment dropout condition due to the frequency fluctuation and / or voltage fluctuation stored in the power demand equipment dropout condition database A microgrid operation apparatus comprising a device dropout determination unit that determines whether a power demand device is dropped based on the above.
In the microgrid operation device according to claim 3,
For each power demand device, storing data indicating whether or not suppression is possible and whether or not it is possible to drop off, and the data indicating whether or not suppression is provided with a power demand device suppression condition database including time that can be suppressed for the power demand device,
The control method formulation unit indicates the frequency variation and / or voltage variation at the time of the independent operation calculated by the independent time zone system state calculation unit, and the suppression availability and dropout availability stored in the power demand device suppression condition database. A microgrid operation apparatus characterized by selecting a power demand device to be suppressed based on data.
In the microgrid operation device according to claim 3,
The control method formulation unit selects, as a power demand device, a power demand device connected to a point where frequency fluctuation and / or voltage fluctuation at the time of shifting to a self-sustained operation is large. .
In the microgrid operation device according to claim 3,
The microgrid operation apparatus characterized in that the control method formulating unit selects, as a power demand device, a power demand device that easily falls off due to a frequency fluctuation at the time of transition to independent operation.
In the microgrid operation device according to claim 3,
The microgrid operation apparatus characterized in that the control method formulating unit selects, as a power demand device, a power demand device that easily drops due to a voltage fluctuation at the time of shifting to a self-sustaining operation.
In the microgrid operation device according to claim 3,
The microgrid operation apparatus, wherein the control method formulation unit selects a power demand device having a large fluctuation in power consumption when shifting to a self-sustaining operation as a power demand device to be suppressed.
In the microgrid operation device according to claim 4,
The equipment drop-off determination unit performs drop-out determination of an induction motor as a power demand device based on a drop condition of the power demand device due to frequency variation and / or voltage variation stored in the power demand device drop condition database. A featured microgrid operation device.
In the microgrid operation device according to claim 5,
The equipment drop-off determination unit performs drop-out determination of an induction motor as a power demand device based on a drop condition of the power demand device due to frequency variation and / or voltage variation stored in the power demand device drop condition database. A featured microgrid operation device.
In the microgrid operation device according to claim 6,
The equipment drop-off determination unit performs drop-out determination of an induction motor as a power demand device based on a drop condition of the power demand device due to frequency variation and / or voltage variation stored in the power demand device drop condition database. A featured microgrid operation device.
In the microgrid operation device according to claim 7,
The equipment drop-off determination unit performs drop-out determination of an induction motor as a power demand device based on a drop condition of the power demand device due to frequency variation and / or voltage variation stored in the power demand device drop condition database. A featured microgrid operation device.
In the microgrid operation device according to claim 4,
The device dropout determination unit performs dropout determination of an inverter as a power demand device based on a dropout condition of the power demand device due to frequency variation and / or voltage variation stored in the power demand device dropout condition database. A microgrid operation device.
In the microgrid operation device according to claim 5,
The device dropout determination unit performs dropout determination of an inverter as a power demand device based on a dropout condition of the power demand device due to frequency variation and / or voltage variation stored in the power demand device dropout condition database. A microgrid operation device.
In the microgrid operation device according to claim 6,
The device dropout determination unit performs dropout determination of an inverter as a power demand device based on a dropout condition of the power demand device due to frequency variation and / or voltage variation stored in the power demand device dropout condition database. A microgrid operation device.
This is a method for uninterruptible transition from grid-connected operation to commercial grid operation to commercial grid, and predicts the current grid status of the grid from the measurement data, and at least power demand equipment in the grid grid Power that determines dropout during self-sustained operation based on dropout conditions including frequency fluctuation and / or voltage fluctuation stored every time, and suppresses the power that can be used to increase using the frequency fluctuation and / or voltage fluctuation. A microgrid operation method comprising: selecting a demand device and performing suppression of the selected power demand device before transition to independent operation.
The microgrid operation method according to claim 16, wherein
Referring to the power demand equipment dropout condition database that stores the power demand equipment dropout conditions associated with frequency fluctuations and / or voltage fluctuations in association with the types of power demand equipment and the amount of power used, the power demand equipment dropouts during autonomous operation A method of operating a microgrid, characterized by determining
The microgrid operation method according to claim 17,
For each power demand device, storing data indicating whether or not suppression is possible and whether or not it is possible to drop off, and the data indicating whether or not suppression is referred to a power demand device suppression condition database including time that can be suppressed for the power demand device,
A power demand device to be suppressed is selected based on frequency variation and / or voltage variation during self-sustained operation and data indicating the suppression availability and dropout availability stored in the power demand device suppression condition database. Grid operation method.
The microgrid operation method according to claim 17,
A method for operating a microgrid, comprising: selecting a power demand device connected to a point having a large frequency fluctuation and / or voltage fluctuation at the time of transition to independent operation as a power demand device to be suppressed.
The microgrid operation method according to claim 17,
A method for operating a microgrid characterized by selecting, as a power demand device, a power demand device that easily falls off due to frequency fluctuations when shifting to a self-sustaining operation.