JP2013121208A - Power system control system and power system control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To operate a power system stably.SOLUTION: In a power system 1 including a system controller 4 and a measurement device 8, the system controller 4 comprises: a prediction unit for generating prediction information by predicting a consumer 7 where the power value changes more than a predetermined magnitude and the time zone thereof, based on the power information transmitted from each measurement device 8; and a prediction information transmission unit for transmitting the prediction information to each measurement device 8 in a prediction area where a predetermined number or more of predicted consumers 7 exist. The measurement device 8 includes a measurement unit for measuring the power value at a predetermined time interval, and a power information transmission unit for transmitting the power information including the power values measured, based on the prediction information transmitted from the system controller 4, at any one of a first time interval or a second time interval longer than the first period to the system controller 4.

Description

  The present invention relates to a power system control system and a power system control method.

  In recent years, power generation devices that use natural energy, such as solar power generation devices (hereinafter referred to as “PV (Photovoltaic) power generation devices”) or wind power generation devices, are installed in various places. These are called distributed power sources because they are often geographically dispersed compared to existing thermal power generators, hydroelectric generators, nuclear power generators, and the like. Conventionally, consumers (private houses, buildings, factories, etc.) have only been supplied with electric power from the electric power system, but in recent years, consumers can supply electric power generated by PV power generators to the electric power system. Became.

  High stability is required for the power system that bears the social infrastructure. Therefore, a voltage regulator is installed in the power system in order to stabilize the voltage of the system power. As such a voltage regulator, for example, there is a load ratio control transformer (LRT), a step voltage regulator (SVR), or a static var compensator (SVC). In any voltage regulator, in order to properly adjust the voltage, it is necessary to measure (sample) the voltage of the power system with high accuracy. An allowable range is defined for the voltage of the power supplied from the power system to the consumer. For example, the domestic allowable range is defined as 101 ± 6V. The voltage adjustment device adjusts the voltage so that the voltage of the electric power supplied to the consumer falls within this allowable range.

  In recent years, a measuring device called a smart meter that measures information on power generation and power consumption (hereinafter referred to as “power information”) is installed in each consumer, and AMI (Automatic Measuring Infrastructure) receives power information from each smart meter. A collection system is being considered. The measuring device measures the voltage, current, power factor, and the like of the power generated and consumed by the consumer, and transmits the measured value to the AMI. The measuring device is configured as a sensor-equipped switch, for example. The sensor-equipped switch has an opening / closing function for switching the distribution system and a function for measuring a voltage at an installation location. In general, the measurement device transmits power information to the AMI at predetermined time intervals. The AMI collects power information from each measuring device and transmits it to a system control device that manages and controls the power system. The system control device calculates the power rate of each consumer based on the power information transmitted from the AMI.

  The measuring device includes an A / D (Analog / Digital) converter that converts a power value measured as an analog signal into a digital signal. When converting an analog signal to a digital signal, the measurement device sets a sampling rate based on the sampling theorem so that information on the analog signal is not largely lost.

  Patent Document 1 describes that the sampling rate is variable in accordance with a change in the frequency of the power system.

  Patent Document 2 describes that the amount of electricity is sampled and converted into a digital signal, and the interval between signals extracted from the digital signal is made variable in accordance with the measured rate of change of the amount of electricity.

  Non-Patent Document 1 describes a US standardization system regarding an AMI apparatus configuration.

  Non-Patent Document 2 describes the configuration of a device that conforms to Non-Patent Document 1, and describes that 15 minutes, 30 minutes, or 60 minutes can be set as the transmission interval of power information.

Japanese Patent No. 2969724 JP-A-9-243669

American National Standards Institute (ANSI) standard, C12 series AMI system, the base of smart grid, Toshiba review, pp19-22, vol. 65, N0.9, (2010)

  In the PV power generation device, the amount of power generation varies depending on the altitude and azimuth angle of the sun, the weather (such as sunny or cloudy), or the flow of clouds. In particular, the cloud flow changes the amount of power generated by the PV power generation device at very short intervals (for example, every few seconds). The allowable range of the voltage supplied to the consumer is defined as described above. However, when the electric power generated by the PV power generation apparatus owned by the consumer is supplied to the power system, the voltage of the distribution network may rise and deviate from the allowable range.

  The power system can be affected by natural disasters. For example, there is a risk of transmission line disconnection due to strong winds, equipment failure due to lightning strikes, system disruption due to large-scale earthquakes, and communication failures. When these failures occur, the power of the power system may become unstable.

  An object of the present invention is to provide a power system control system and a power system control method that enable stable operation of a power system.

  Another object of the present invention is to provide a power system control system and a power system control method for controlling a voltage regulator so that a voltage supplied to a consumer falls within an allowable range.

  A power system control system for controlling a power system for supplying power to a consumer according to an embodiment of the present invention measures a power value generated or consumed by a consumer, and generates power information including the power value A measuring device that controls the measuring device and the power system, and a communication path that enables information transmission between the measuring device and the system control device. The grid control device includes a power information receiving unit that receives power information transmitted from each measurement device via a communication path, and a customer whose power value changes by a predetermined magnitude or more based on a plurality of received power information. Prediction information transmission that predicts the time zone and generates prediction information including the predicted time zone and each measurement device in the prediction area that is the area where the predicted consumer exists. A part. The measurement device includes a measurement unit that measures the power value at predetermined time intervals, a prediction information reception unit that receives the prediction information transmitted from the system control device, and a first time interval or a first time based on the prediction information It is determined whether the power information should be transmitted at any one of the second time intervals longer than the time interval, and the power information including the power value measured by the measuring unit is transmitted to the system control device at the determined time interval. And a power information transmission unit.

  In a preferred embodiment, the power information transmission unit included in the measurement device may determine to transmit power information to the system control device at a first time interval during a time period included in the prediction information. .

  In a preferred embodiment, there is further provided a voltage adjustment device capable of adjusting a voltage of electric power supplied to a consumer, and a solar power generation device capable of generating electric power when receiving sunlight and supplying the generated electric power to an electric power system. And the system control device controls the voltage regulator so that the voltage of the power supplied to the consumer does not deviate from a predetermined range based on the power information transmitted from the measuring device at the first time interval. A control unit may be further provided.

FIG. 1 is a schematic diagram illustrating the entire power system control system according to the first embodiment. FIG. 2 is a sequence diagram illustrating a process in which the measurement device notifies the grid control device of power information. FIG. 3 is a graph showing changes in the voltage value of power in the transmission line. FIG. 4 is a block diagram illustrating a hardware configuration of the system control device. FIG. 5 is a block diagram illustrating a hardware configuration of the measurement apparatus. FIG. 6 is a block diagram illustrating a functional configuration of the system control device. FIG. 7 is an explanatory diagram showing the movement of each area and cloud. FIG. 8 is a block diagram illustrating a functional configuration of a controller included in the measurement device. FIG. 9 is an explanatory diagram showing a state in which an analog signal is sampled and converted into a digital signal. FIG. 10 is a flowchart showing processing of the measuring unit included in the system control device. FIG. 11 is a flowchart illustrating processing of the SVR control unit included in the system control device. FIG. 12 is a flowchart showing the processing of the rate converter included in the measurement device. FIG. 13 is an explanatory diagram when the power system control system is compared to control theory. FIG. 14 is a block diagram illustrating a functional configuration of the measurement apparatus according to the second embodiment. FIG. 15 is a block diagram illustrating a functional configuration of the measurement apparatus according to the third embodiment. FIG. 16 is an explanatory diagram of a method for determining an end time of a time zone in which power information should be reported in detail. FIG. 17 is a block diagram illustrating a functional configuration of the system control apparatus according to the fourth embodiment. FIG. 18 is a block diagram illustrating a functional configuration of the measurement apparatus according to the fourth embodiment. FIG. 19 is an explanatory diagram illustrating a state where a disaster has occurred in the power system.

  FIG. 1 is a schematic diagram illustrating the entire power system control system according to the first embodiment.

  In the power system control system 1, for example, a power plant 2, a substation 3, and a distribution station 5 are connected by a power transmission line 10 (a power transmission station is not illustrated). The power distribution station 5, the SVR 9, and the pole transformer 13 are connected by a power transmission line 11 (feeder line 11). The pole transformer 13, the switchboard (not shown) of the customer 7, and the PV power generator 6 are connected by a distribution line 14 (lead-in wire 14). The system control device 4, the SVR 9, and the measurement device 8 are connected by a communication line 12. The measuring device 8 is connected between the switchboard of the customer 7 and the pole transformer 13.

  The power plant 2 transmits the generated power from the power transmission station to the substation 3 via the power transmission line 10. The power plant 2 is, for example, a thermal power plant, a hydro power plant, a nuclear power plant, or the like.

  The substation 3 converts the electric power from the power transmission station into a predetermined voltage value and distributes it to each distribution station 5. A plurality of substations 3 may exist between the power plant 2 and the distribution station 5.

  The distribution station 5 converts the electric power supplied from the substation 3 through the power transmission line 10 into a predetermined voltage and transmits it to each customer 7 through the power transmission line 11. In this embodiment, the group of customers 7 connected to one power transmission line 11 is managed as one area. For example, in FIG. 1, a group of customers 7 connected to each of the power transmission lines 11a, 11b, 11c, and 11d is defined as areas A1, A2, A3, and A4, respectively.

  The SVR 9 receives a voltage control signal for controlling the voltage from the system control device 4 via the communication line 12. SVR9 is installed in the middle of the power transmission line 11, and adjusts so that the voltage of the electric power supplied to each consumer 7 may fall within an allowable range. Details of the SVR 9 will be described later. In the present embodiment, SVR is used as the voltage regulator, but SVC, LRT, or the like may be used.

  The PV power generation device 6 generates electric power when receiving sunlight. The amount of power generated by the PV power generation device 6 is greatly affected by the weather. For example, the power generation amount of the PV power generation device 6 increases when it is clear (the amount of solar radiation is large), and decreases when it is cloudy (the amount of solar radiation is small).

  The consumer 7 can receive power supply from an electric power company or the like via the distribution line 14. The consumer 7 including the PV power generation device 6 can supply the power generated by the PV power generation device 6 to an electric power company or the like via the distribution line 14.

  The measuring device 8 measures the amount of power consumed by the customer 7 (power consumption) and the amount of power generated by the customer 7 (power generation amount). Information regarding these power consumption and power generation is referred to as power information in this embodiment. The power information is not limited to the power consumption amount and the power generation amount, and may include a voltage value, a current value, or a power factor. The power information is generally used for calculating a power charge. Details of the measuring device 8 will be described later.

  The system control device 4 receives power information from each measurement device 8 via the communication line 12. In the present embodiment, AMI is omitted. The system control device 4 generates a voltage control signal based on the received power information. The system control device 4 transmits the generated voltage control signal to the SVR 9 via the communication line 12. Details of the system control device 4 will be described later.

  The communication line 12 is a line capable of bidirectional data communication. The communication line 12 may be the same line as the power transmission line 11, or may be another line composed of an optical fiber cable or the like. A part or all of the communication line 12 is not necessarily wired, and may be wireless communication, for example. In addition, when transmitting the same data to a large number, broadcast waves may be used instead of the communication line 12.

  FIG. 2 is a sequence diagram illustrating a process in which the measurement device 8 notifies the grid control device 4 of power information. As described above, the measurement device 8 notifies the system control device 4 of the power information via the communication line 12. Hereinafter, some examples of notification means will be given.

  (1) As shown in FIG. 2 (a), the first notification means is configured so that each measuring device 8 transmits the measured power information to the so-called push format via the relay device 15 (not shown in FIG. 1). (S101 to S102). The merit of the first notification means is that the system control device 4 can know the power information measured by the measurement device 8 almost in real time by the push-type notification. Note that there may be a plurality of relay apparatuses 15 or none. In the latter case, each measuring device 8 transmits power information directly to the system control device 4.

  (2) As shown in FIG. 2B, the second notification means notifies each relay device 15 of the power information to the relay device 15 in a push type (S103). And the relay apparatus 15 once collects the electric power information notified from each measuring device 8, and notifies it to the system | strain control apparatus 4 (S104). The merit of the second notification means is that the relay device 15 once collects a plurality of pieces of power information, so that it is possible to reduce the load of reception processing in the system control device 4.

  (3) As shown in FIG. 2 (c), the third notification means transfers the power information between the adjacent measurement devices 8 to the relay device 15 in a so-called bucket relay format (S105 to S107). Then, the relay device 15 notifies the system control device 4 of the transferred power information in a push format (S108). The measuring device 8 (2) that transfers the power information adds its own power information to the power information transferred from the measuring device 8 (1) and transfers it to the next measuring device 8 (3). Also good. The merit of the third notification means is that communication traffic on the communication line 12 between the measuring device 8 and the relay device 15 can be reduced.

  (4) In the fourth notification unit, as shown in FIG. 2D, the system control device 4 requests power information from the relay device 15 (S109). In response to the request, the relay device 15 requests power information from each measuring device 8 (S110). Each measuring device 8 receives the request and returns power information to the relay device 15 (S111). The relay device 15 collects the power information returned from each measuring device 8 and sends it back to the system control device 4 (S112). That is, the system control device 4 acquires power information from the measurement device 8 in a so-called pull format. The merit of the fourth notification means is that the system control device 4 can know the power information of the measuring device 8 at an arbitrary timing.

  In this embodiment, it is assumed that the first notification means is used. In this embodiment, the relay device 15 is not present. However, this invention is not limited to this, Any notification means of said (1)-(4) may be used, they may be used in combination, and another notification means may be used. .

  Next, a problem when a large number of consumers install a PV power generation device will be described.

  FIG. 3 is a graph showing changes in the voltage value of power in the transmission line.

  As described above, the voltage of the electric power supplied to the consumer 7 needs to be within the specified voltage allowable range. Therefore, the SVR 9 adjusts (transforms) the voltage of the electric power supplied to the consumer 7 so as to be within an allowable range. For example, in the SVR 9, the voltage value of the electric power supplied to the customer 7 is between the upper limit value VU (for example, 101 + 6V) and the lower limit value VL (for example, 101-6V) of the allowable range shown in FIG. Adjust the voltage to.

  Since the voltage value decreases in proportion to the transmission distance, the SVR 9 generally increases the voltage (boost). For example, in FIG. 3A, the voltage value 120 of the customer 7 at the point D4 falls within the allowable range (VL to VU) by the SVR 9 at the point D2 performing step-up (121).

  However, when the PV power generation device 6 of the customer 7 at the point D4 generates power, the voltage of the customer 7 at the point D4 increases. In this case, when the SVR 9 at the point D2 boosts (121) as in FIG. 3 (a), the voltage value 120 of the consumer 7 at the point D4 is within the allowable range as shown in FIG. 3 (b). Deviation (122) from (VL to VU).

  Therefore, as shown in FIG. 3C, if the SVR 9 at the point D2 does not boost, the voltage value 120 of the customer 7 at the point D4 can be kept within an allowable range (VL to VU).

  That is, when the voltage value 120 of the customer 7 deviates from the allowable range (VL to VU) due to the power generation of the PV power generation device 6 of the customer 7, the SVR 9 at the point D2 is not boosted. Thus, the voltage value 120 of the consumer 7 can be within the allowable range (VL to VU). This determination method will be described later.

  FIG. 4 is a block diagram illustrating a hardware configuration of the system control device. The system control device 4 includes a CPU (Central Processing Unit) 21, a memory 22, a storage device 23, and a communication interface (hereinafter referred to as “I / F”) 24. These elements 21 to 24 are connected by a bus 25 capable of bidirectional data transmission. The CPU 21 and the memory 22 may be collectively regarded as the controller 20.

  The CPU 21 reads out and executes a computer program (hereinafter referred to as “program”) held in the storage device 23, thereby realizing various functions of the system control device 4 described later.

  The memory 22 temporarily holds data necessary for the CPU 21 to execute the program. The memory 22 is, for example, a DRAM (Dynamic Random Access Memory).

  The storage device 23 holds a program executed by the CPU 21, data necessary for executing the program, and the like. The storage device 23 includes, for example, a nonvolatile storage medium such as an HDD (Hard Disk Drive) or a flash memory.

  The communication I / F 24 is connected to the communication line 12. The communication I / F 14 transmits and receives data to and from other devices via the communication line 12.

  FIG. 5 is a block diagram showing a hardware configuration of the measuring device 8. The measuring device 8 includes, for example, an amplifier 31, an A / D converter 32, a buffer memory 33, a rate converter 34, a transmission device 35, a communication interface 36, a controller 37, and a measuring instrument 38. .

  The measuring instrument 38 measures the amount of power consumed and the amount of power generated by the customer 7 (hereinafter referred to as “power value”). The measuring instrument 38 may measure, for example, a voltage value, a current value, or a power factor.

  The amplifier 31 is connected to the output side of the measuring instrument 38. The amplifier 31 amplifies and outputs an analog signal indicating the power value output from the measuring instrument 38.

  The A / D converter 32 is connected to the output side of the amplifier 31. When the analog signal amplified by the amplifier 31 is input, the A / D converter 32 samples the analog signal at a predetermined sampling rate, converts it to a digital signal, and outputs the digital signal.

  The buffer memory 33 is connected to the output side of the A / D converter 32. The buffer memory 33 is used to correct a time lag of the digital signal converted by the A / D converter 32. That is, the digital signal output from the buffer memory 33 is corrected for a time lag.

  The rate converter 34 is connected to the output side of the buffer memory 33. When the digital signal whose time lag has been corrected by the buffer memory 33 is input to the rate converter 34, the rate converter 34 converts the sampling rate of the digital signal. For example, the rate converter 34 lowers the sampling rate of a certain time zone of the digital signal by rate conversion processing. Thereby, the data amount of a digital signal can be reduced. The rate conversion process of the sampling rate is realized using, for example, a low-pass filter.

  The transmission device 35 is connected to the output side of the rate converter 34. When the digital signal that has been rate-converted by the rate converter 34 is input to the transmission device 35, the transmission device 35 generates power information that is a data format that can be processed by the system control device 4 based on the digital signal. The transmission device 35 outputs the generated power information to the communication I / F 36.

  The communication I / F 36 is connected between the output side of the transmission device 35 and the communication line 12. When receiving the prediction information from the system control device 4, the communication I / F 36 transmits the prediction information to the controller 37. When receiving power information from the transmission device 35, the communication I / F 36 transmits the power information to the system control device 4.

  The controller 37 is connected to the amplifier 31, the A / D converter 32, the buffer memory 33, the rate converter 34, the transmission device 35, and the communication I / F 36. The controller 37 sets an amplification value and an offset value of the analog signal for the amplifier 31. The controller 37 sets a sampling rate for converting an analog signal into a digital signal for the A / D converter 32. The controller 37 sets a rate value after conversion and a time zone for converting the rate to the rate converter 34. The controller 37 sets a transmission interval (transmission cycle) of power information and the like for the transmission device 35. Details of the controller 35 will be described later.

  The measurement device 8 is not limited to the configuration of FIG. 5, and may be a configuration in which the transmission device 35 includes the function of the rate converter 34, for example. The measuring device 8 may include a CPU, a memory, and a storage medium, and may realize the above functions by a computer program.

  FIG. 6 is a block diagram illustrating a functional configuration of the system control device. The system control device 4 includes a power information reception unit 41, a prediction unit 42, an SVR control unit 43, and a prediction information transmission unit 44. These functions 41 to 44 are realized by, for example, reading a corresponding program into the CPU 21 and executing it.

  The power information receiving unit 41 receives power information from each measuring device 8 and holds it in the storage device 23.

  Based on the received power information, the predicting unit 42 predicts an area where the power generation amount is expected to change greatly and a time zone where the power generation amount is expected to change greatly in the area. Then, the prediction unit 42 provides detailed power information (for example, at shorter time intervals) in the time zone in which the power generation amount is predicted to change greatly with respect to the measurement device 8 in the area where the power generation amount is predicted to change significantly. Request to report. Because, if the power information report time interval is long even though the power generation amount has changed greatly, if the SVR 9 is requested to adjust the voltage after receiving the report, the adjustment There is a risk of not being in time. That is, there is a risk that a voltage deviation occurs in the customer 7.

  In the present embodiment, information including an area and a time zone where the power generation amount is predicted to change greatly is referred to as “prediction information”. The prediction unit 42 transmits prediction information to each measurement device 8 existing in an area where the power generation amount is predicted to change greatly. The prediction unit 42 may transmit the prediction information to each measurement device 8 in a predetermined area via the communication line 12, or predicts simultaneously to the measurement devices 8 in the predetermined area using radio waves as in broadcasting. Information may be distributed.

  Next, an area and time zone prediction method in which the power generation amount is considered to change greatly will be described.

  FIG. 7 is an explanatory diagram showing the movement of each area and cloud.

  The amount of power generated by the PV power generation device 6 is greatly affected by the weather. Generally, the power generation amount of the PV power generation device 6 is large when it is clear (when the amount of solar radiation is large) and small when it is cloudy (when the amount of solar radiation is small). In FIG. 7, since the cloud 131 exists in the area A1 at time t0, the power generation amount of the PV power generation device 6 in the area A1 is small. At time t0, there is no cloud 131 in area A2, so the amount of power generated by PV power generation device 6 in area A2 is large.

  Here, it is assumed that time elapses from time t0 to time t1, and the cloud 131 moves from area A1 to area A2. In this case, the power generation amount of the PV power generation device 6 in the area A1 where the cloud 131 no longer exists is larger than that at the time t0. On the other hand, the power generation amount of the PV power generation device 6 in the area A2 covered with the clouds 131 is smaller than that at the time t0. That is, from time t0 to time t1, the power generation amount of the PV power generation device 6 in the area A1 increases and the power generation amount of the PV power generation device 6 in the area A2 decreases.

  From this, it can be estimated that the cloud 131 has moved from west to east (the left direction in FIG. 7 is west and the right direction is east). Therefore, it can be predicted that the cloud 131 will move to the area A3 in the future. Therefore, it can be predicted that the power generation amount of the PV power generation device 6 in area A3 will greatly decrease in the future from time t2 (t2> t1). Therefore, the prediction unit 42 transmits the prediction information to the measurement device 8 in the area A3, and requests to report the power information in detail (at short time intervals) in the time zone before and after the time t2. Thereby, the system | strain control apparatus 4 can know in detail the change of the electric power generation amount of each consumer 7 of area A3.

  The prediction unit 42 similarly transmits the prediction information to the measurement device 8 in the area A2 that is predicted to become clear when the cloud 131 moves, and requests the power information to be reported in detail. This is because the amount of power generation changes greatly when it changes from cloudy to sunny.

  Clouds do not necessarily move in a certain direction. Therefore, the prediction unit 42 may also transmit the prediction information to the measurement device 8 in the area adjacent to the predicted area of the cloud and request that the power information be reported in detail. For example, when it is predicted that the cloud 131 moves from the area A2 to the area A3 at the time t2, the prediction unit 42 also transmits the prediction information to the neighboring area A13 and the measuring device 8 in the area A23 of the area A3, Requests detailed reporting of power information. Thereby, even if the cloud 131 deviates from the prediction and moves to either the area A13 or the area A23, the system control device 4 can know in detail that the power generation amount has changed greatly.

  Next, several means for predicting changes in the weather in each area are listed.

  (1) As described above, the first prediction means predicts future weather changes in each area based on changes in the amount of power generated by the PV power generation device 6 in each area. For example, when the power generation amount of the PV power generation device 6 is greatly reduced, it can be estimated that the cloud has moved to that area. On the contrary, when the power generation amount of the PV power generation device 6 greatly increases, it can be estimated that the cloud has left the area. That is, it is possible to estimate how the clouds are moving by observing changes in the power generation amount of the PV power generation devices 6 in each area.

  (2) The second prediction means uses a weather forecast announced by the Japan Meteorological Agency or the like. For example, the prediction unit 42 acquires future weather forecasts for each area, and predicts areas that will change from cloudy to sunny and from sunny to cloudy in the future.

  (3) The third predicting means is that the system control device 4 periodically collects information on the current local weather from each customer 7 and predicts future weather changes in each area based on the information. . For example, when each customer 7 is equipped with a sunshine meter, the prediction unit 42 periodically collects the measurement values of the sunshine meter, and thus the movement of the cloud is similar to the first prediction means described above. Can be estimated.

  In this embodiment, the first prediction means (1) is used. However, it is not limited to the first prediction means, and any of the prediction means (1) to (3) may be used, or these prediction means may be used in combination. Alternatively, other prediction means may be used.

  Returning to FIG. The SVR control unit 43 transmits a voltage control signal for adjusting the voltage to each SVR 9. As described above (see FIG. 3), when the power generation amount of the PV power generation device 6 of the consumer 7 is large, if the voltage is boosted by the SVR 9, the voltage of the consumer 7 may exceed the upper limit of the allowable range. Conversely, if the SVR 9 does not boost when the amount of power generated by the PV power generation device 6 of the customer 7 is small, the voltage of the customer 7 may fall below the lower limit of the allowable range. Therefore, the SVR control unit 43 determines whether or not boosting should be performed in each SVR 9 based on the power generation amount of the PV power generation device 6 of the consumer 7 and transmits a voltage control signal.

  The SVR control unit 43 can predict that the power generation amount of the PV power generation device 6 in the area predicted to clear in the future in the prediction unit 42 will increase in the future. Therefore, the SVR control unit 43 transmits a voltage control signal indicating that boosting is not performed to the SVR 9 in an area predicted to be sunny in the future. The SVR control unit 43 can predict that the power generation amount of the PV power generation apparatus 6 in the area predicted to be cloudy in the future in the prediction unit 42 will be reduced in the future. Therefore, the SVR control unit 43 transmits a voltage control signal for boosting to the SVR 9 in the area predicted to be cloudy in the future. The SVR control unit 43 may transmit the voltage control signal only when boosting or when boosting is not performed. Thereby, the SVR control unit 43 can control the SVR 9 so that the voltage of the customer 7 is within the allowable range.

  FIG. 8 is a block diagram showing a functional configuration of the controller 37 provided in the measuring device 8. The controller 37 of the measuring device 8 includes, for example, a prediction information receiving unit 51, a sampling setting unit 52, a rate conversion setting unit 53, and a transmission setting unit 54.

  The prediction information receiving unit 51 has a function of receiving prediction information. The prediction information receiving unit 51 receives the prediction information from the system control device 4 by controlling the communication I / F 36. The prediction information receiving unit 51 holds the received prediction information in the storage device 23.

  The sampling setting unit 52 is a function for setting the sampling rate. The sampling setting unit 52 sets a sampling rate for converting an input analog signal into a digital signal for the A / D converter 32. Based on the sampling theorem, this sampling rate is a rate at which the information on the power value held by the analog signal is not largely lost. For example, the sampling rate is several milliseconds to several seconds.

  The rate conversion setting unit 53 is a function for setting a rate conversion amount. The rate conversion setting unit 53 sets, for the rate converter 34, the rate at which the digital signal input in which time zone is to be reduced. For example, the rate conversion setting unit 53 sets the digital signal in a time zone other than the time zone for which a detailed report is requested by the prediction information to be reduced to a predetermined rate. In other words, the rate conversion setting unit 53 keeps the rate of the digital signal in the time zone requested by the prediction information as it is, and reduces the digital signal in the time zone not requested by the prediction information to a predetermined rate. Thereby, the system control apparatus 4 can know in detail the change in the power generation amount in the time zone in which the change in the power generation amount is predicted to be large. Furthermore, the amount of power information data can be reduced in a time period in which the change in power generation amount is expected to be not so large. Details of the sampling rate conversion means will be described later.

  The transmission setting unit 54 is a function for setting the transmission device 35. The transmission setting unit 54 causes the transmission device 35 to generate power information based on the digital signal whose rate is converted by the rate converter 34. The transmission setting unit 54 sets a time interval for transmitting the generated power information to the transmission device 35. For example, the transmission setting unit 54 synchronizes the time interval for transmitting the power information with the sampling rate. That is, the transmission setting unit 54 transmits the power information at a relatively long time interval (for example, several minutes to several tens of minutes) in a time zone with a low sampling rate, and a relatively short time interval in a time zone with a high sampling rate. (For example, several milliseconds to several seconds). Thereby, the system control apparatus 4 can know the change in the amount of power generation almost in real time for the time zone for which a detailed report is requested by the prediction information.

  FIG. 9 is an explanatory diagram showing a state in which an analog signal is sampled and converted into a digital signal. Hereinafter, the process of converting an analog signal into a digital signal in the measurement apparatus 8 will be described with reference to FIG.

  FIG. 9A is an analog signal 141 indicating the amount of power measured by the measuring device 8. Here, the horizontal axis is time t, and the vertical axis is the electric energy W. The analog signal 141 is input to the A / D converter 32 and converted into a digital signal 142 shown in FIG. 9B at a predetermined sampling rate (for example, at intervals of several seconds).

  The rate converter 34 converts the digital signal 142 shown in FIG. 9B to the sampling rate of the digital signal 142 in the time zone 145 other than the time zone 144 specified by the prediction information, as shown in FIG. 9C. , Convert to a lower rate. For example, the rate converter 34 converts the rate of the digital signal 142 in the time zone 145 that was several seconds apart into minutes.

  Below are some means of converting to lower rates.

  (1) The first rate conversion means thins out the power value indicated by the digital signal at a predetermined rate. For example, the rate can be reduced to about 1/3 by thinning out the three power values indicated by the digital signal in the time zone 143 in FIG. 9B at a rate of about 2/3.

  (2) The second rate conversion means averages the power value indicated by the digital signal at a predetermined ratio. For example, by averaging the three power values indicated by the digital signal in the time zone 143 in FIG. 9B to obtain one power value, the rate can be reduced to about ３.

  In this embodiment, the first rate conversion means (1) is used. However, it is not limited to the first rate conversion means, and any of the rate conversion means (1) to (2) may be used. Alternatively, these rate conversion means may be used in combination, or other rate conversion means may be used.

  FIG. 10 is a flowchart showing the processing of the prediction unit 42 included in the system control device 4.

  The prediction unit 42 reads out the power information held in the storage device 23 (S201). Registration of the power information in the storage device 23 is performed by the power information receiving unit 41 as needed.

  The prediction unit 42 analyzes temporal changes in the amount of power generation based on the power information, and predicts areas and time zones in which the weather is expected to change significantly in the future (S202).

  For each area where the weather is predicted to change significantly in the future (hereinafter referred to as “prediction area”), the prediction unit 42 includes a time zone (hereinafter referred to as “prediction time zone”) where the weather is predicted to change greatly in the area. Information is generated (S203).

  The prediction unit 42 transmits the prediction information generated for the prediction area to each measurement device 8 in the prediction area (S204).

  Through the above processing, the prediction unit 42 reports power information at a relatively short time interval for each measurement device 8 in the area where the weather is predicted to change significantly for the time zone where the weather is predicted to change significantly. To request.

  FIG. 11 is a flowchart showing the processing of the SVR control unit 43 included in the system control device 4.

  The SVR control unit 43 analyzes the voltage value of the power information reported in detail from each measuring device 8 (S211).

  The SVR control unit 43 determines whether or not there is a customer 7 having a voltage value equal to or higher than a predetermined threshold value in each area (S212).

  When there is a customer 7 having a voltage value equal to or higher than a predetermined threshold (S212: YES), the SVR control unit 43 specifies SVR 9 to be controlled to keep the voltage of the customer 7 within an allowable range. (S213). Then, the SVR control unit 43 transmits a voltage control signal for requesting not to boost the specified SVR 9 (S214).

  When there is no customer 7 whose voltage value is equal to or higher than the predetermined threshold (S212: NO), the SVR control unit 43 transmits a voltage control signal for requesting boosting as usual to each SVR9. (S215).

  Through the above processing, the system control device 4 can control the boosting of the SVR 9 so that the voltage of the customer 7 is within the allowable range. The reason for this will be described below. The measuring device 8 in the area where the weather is predicted to change significantly in the prediction unit 42 reports the power information to the system control device 4 at a relatively short time interval. Therefore, the system control apparatus 4 can know the timing when the voltage of the consumer 7 becomes equal to or higher than the predetermined threshold value almost in real time. Therefore, the system controller 4 can transmit to the SVR 9 a voltage control signal indicating that boosting is not immediately performed when the voltage of the consumer 7 becomes equal to or higher than a predetermined threshold value. Thereby, even if it is a case where the voltage of the consumer 7 rises because the PV power generation device 6 of the consumer 7 generates power, the SVR 9 can adjust the voltage of the consumer 7 to be within an allowable range.

  If the time interval in which the measurement device 8 reports the power information to the system control device 4 is relatively long as in the conventional case, it is difficult for the SVR 9 to adjust the voltage of the customer 7 to be within an allowable range. . This is because in this case, the system control device 4 knows it after a considerable delay from the timing when the voltage of the customer 7 becomes equal to or higher than a predetermined threshold value. Therefore, the voltage of the customer 7 continues to deviate from the allowable range for a while until the system control device 4 transmits a voltage control signal indicating that boosting is not performed to the SVR 9. However, according to the present embodiment, as described above, the risk that the voltage of the customer 7 deviates from the allowable range can be reduced.

  FIG. 12 is a flowchart showing processing of the rate converter 34 included in the measuring device 8.

  The rate converter 34 specifies a time zone for which a detailed report is requested in the prediction information (S221).

  The rate converter 34 determines whether or not the current time is included in the time zone specified in step S221 (S222). That is, the rate converter 34 determines whether or not the current time is included in the time zone for which detailed reporting is requested in the prediction information.

  When the current time is included in the specified time zone (S222: YES), the rate converter 34 maintains the rate sampled by the A / D converter 32 for the input digital signal (S223). ). That is, the rate converter 34 does not perform processing for reducing the input digital signal to a predetermined rate.

  If the current time is not included in the specified time zone (S222: NO), the rate converter 34 performs a process of reducing the input digital signal to a predetermined rate (S224).

  By the above processing, the sampling rate in the time zone where the power generation amount or the voltage value is predicted to change greatly increases, and the sampling rate in the other time zones decreases. Therefore, the system control device 4 can know the change in the power generation amount or the voltage value in detail. Furthermore, the data amount of the power information notified from the measuring device 8 to the system control device 4 can be reduced.

  The system configuration described above can also be compared to open loop control and closed loop control in control theory. Next, this will be described.

  FIG. 13 is an explanatory diagram when the power system control system is compared to control theory.

  In FIG. 13, an input value 151 to the system control device 4 is a target value for keeping the voltage of the customer 7 within an allowable range. An output value 152 from the system controller 4 to the SVR 9 is a voltage control signal for keeping the voltage of the customer 7 within an allowable range. The output value 153 from the SVR 9 is the voltage of the customer 7. Output values 151a and 151b from the measuring device 8 to the system control device 4 are power information. The predicted value 155 input to the measuring device is prediction information.

  FIG. 13A shows a configuration when a predicted value is not input to the measuring device 8. In this case, the measuring device 8 feeds back the output value 151a to the system control device 4 only at a relatively long time interval. Therefore, the system control device 4 cannot receive feedback with high real-time characteristics, and cannot converge the output value 153 from the SVR 9 to the target value 151. That is, it can be said that the power system control system shown in FIG. 13A is an open loop control system.

  FIG. 13B shows a configuration when the predicted value 155 is input to the measuring device 8. The measurement device 8 according to the present embodiment is relatively short with respect to the system control device 4 when the change in the output value 153 from the SVR is predicted to be large based on the predicted value 155 from the system control device 4. The output value 151b is fed back at time intervals. Therefore, the system control device 4 can receive feedback with high real-time characteristics, so that the output value 153 from the SVR 9 can be converged to the target value 151. That is, it can be said that the power system control system shown in FIG. 13B is a closed loop control system.

  According to the present embodiment, an area where the weather is expected to change greatly in the future is predicted, and detailed power information reporting is requested only from the measuring device 8 in the area. Therefore, the communication traffic of the communication line 12 and the system control device 4 can reduce the data reception load and processing load.

  According to the present embodiment, a time zone in which the weather is expected to change greatly in the future is predicted, and a detailed power value report is requested to the measuring device 8 only in that time zone. Further, the data reception load and processing load in the system control device 4 can be further reduced.

  According to the present embodiment, the present invention can be realized by using an existing measuring device (for example, a smart meter), which has conventionally been mainly used for calculating a power charge.

  A second embodiment will be described with reference to FIG. In the first embodiment, the measuring device 8 determines a time zone in which the power information should be reported in detail based on the prediction information transmitted from the system control device 4. In the second embodiment, the measuring apparatus 201 autonomously determines a time zone in which power information should be reported in detail.

  FIG. 14 is a block diagram illustrating a functional configuration of the measurement apparatus according to the second embodiment. The controller 202 of the measurement apparatus 201 according to the present embodiment includes, for example, a sampling setting unit 52, a rate conversion setting unit 53, a transmission setting unit 54, and a prediction unit 203. Functional blocks having the same functions as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted or simplified (the same applies to the following embodiments).

  The prediction unit 203 predicts a change in weather in a place where the own measuring device 201 exists. As described in the first embodiment, the prediction means uses a weather forecast announced by the Japan Meteorological Agency, for example. And the prediction part 203 produces | generates the prediction information containing the time slot | zone estimated that a weather changes a lot. The subsequent processing is the same as in the first embodiment. That is, the measurement apparatus 201 according to the present embodiment determines in which time zone the power information should be reported in detail using the prediction information generated by itself.

  According to the present embodiment, it is not necessary for the system control device 4 to generate prediction information, so that the processing load on the system control device 4 can be reduced.

  According to the present embodiment, it is not necessary to transmit the prediction information from the system control device 4 to the measurement device 8, so that the communication traffic on the communication line 12 can be reduced.

  A third embodiment will be described with reference to FIG. In the third example, the prediction information includes only the start time of the time zone in which power information should be reported in detail. That is, the measuring apparatus 211 according to the present embodiment cannot know the end time of the time zone in which power information should be reported in detail from the prediction information. Therefore, the measuring device 211 determines by itself the end time of the time zone in which power information should be reported in detail.

  FIG. 15 is a block diagram illustrating a functional configuration of the measurement apparatus according to the third embodiment. The controller 212 of the measurement apparatus 211 according to the present embodiment includes, for example, a prediction information receiving unit 51, a sampling setting unit 52, a rate conversion setting unit 53, a transmission setting unit 54, and an end time determination unit 213.

  The end time determination unit 213 determines the end time of the time zone in which power information should be reported in detail. Hereinafter, this determination method will be described.

  FIG. 16 is an explanatory diagram of a method for determining an end time of a time zone in which power information should be reported in detail. Several determination methods are listed below.

  (1) In the first determination method, a time at which a predetermined time has elapsed from a start time of a time zone in which power information should be reported in detail is set as an end time. This will be described with reference to FIG. The end time determination unit 213 sets a time 303 at which a predetermined time 302 has elapsed from the start time 301 of the time zone in which power information should be reported in detail as the end time 303. Therefore, the rate converter 34 does not convert the sampling rate between the times 301 and 302, and lowers the sampling rate after the time 302. For the predetermined time 302, a different value may be set for each measuring device 8.

  (2) The second determination method ends reporting power information in detail when the power value does not change significantly for a predetermined time or longer. This will be described with reference to FIG. The measuring device 211 starts a detailed report of power information from time 304. If the end time determination unit 213 determines that the change in the power value continues to be within the range of the threshold value 307 for the predetermined time 306 or more, the end time determination unit 213 ends the detailed reporting of the power information at time 305. Therefore, the rate converter 34 does not convert the sampling rate between the time 304 and the time 305, and lowers the sampling rate after the time 305. The predetermined time 306 and the change threshold value 307 may be set to different values for each measuring device 8.

  According to this embodiment, it is not necessary for the system control device 4 to calculate the end time of the prediction information, so that the processing load on the system control device 4 can be reduced.

  According to the present embodiment, the system control device 4 can receive a more detailed report from the measurement device 211 than when uniform prediction information is transmitted to the measurement device 8 existing in the area.

  A fourth embodiment will be described with reference to FIG. In the fourth embodiment, the grid control device 221 stabilizes the power grid using the power information reported from the measurement device 231 when a disaster occurs.

  FIG. 17 is a block diagram illustrating a functional configuration of the system control apparatus according to the fourth embodiment. The controller 222 of the system control apparatus 221 according to the present embodiment includes, for example, a power information reception unit 41, a prediction unit 42, an SVR control unit 43, and an abnormality determination unit 223.

  The abnormality determination unit 223 determines a measurement device 231, a customer 7, an area, or the like that may have an abnormality based on the power information received from each measurement device 231. For example, when the power information is not transmitted from a certain measurement device 8 for a predetermined time or longer, the abnormality determination unit 223 determines that some abnormality has occurred in the measurement device 231.

  The abnormality determination unit 223 determines that some abnormality (for example, a large-scale disaster or the like) has occurred in an area where the measurement devices 231 exist when power information is not transmitted from a plurality of measurement devices 231 all at once. When such a large-scale abnormality occurs in the power system, the power system tends to become unstable temporarily. Therefore, the system control device 221 requests the power system measurement device 231 in which no other abnormality has occurred to temporarily report the power information in detail. Thereby, the system control device 221 can finely control the power system in which no other abnormality has occurred, and can stabilize the entire power system.

  FIG. 18 is a block diagram illustrating a functional configuration of the measurement apparatus 231 according to the fourth embodiment. The measuring apparatus 231 according to the present embodiment includes, for example, a prediction information receiving unit 51, a sampling setting unit 52, a rate conversion setting unit 53, a transmission setting unit 54, a prediction unit 42, and an abnormal time control unit 233. .

  The abnormality control unit 233 determines whether there is a possibility that an abnormality has occurred in the area where the measuring device 231 exists. For example, the abnormal time control unit 233 determines that its own area is disconnected from the power system when communication with the system control device 221 becomes impossible. When the area is separated from the power system, the power from the power plant 2 is not supplied to the consumers 7 in this area. In this case, it is desirable that the electric power generated by each PV power generation device 6 in the area is interchanged by the consumers 7 in the area. However, the power generation amount of the PV power generation device 6 is unstable because it is greatly affected by the weather. Therefore, in order to keep the voltage of each customer 7 within the allowable range, the voltage control of the SVR 9 must be finely performed. Therefore, when it is determined that an abnormality has occurred, the abnormality control unit 233 observes a change in the power value at the sampling rate converted by the A / D converter 32 (that is, at a short time interval), and based on that Voltage control of SVR9 is performed.

  FIG. 19 is an explanatory diagram illustrating a state where a disaster has occurred in the power system.

  For example, as shown in FIG. 19, it is assumed that an abnormality such as a disaster has occurred at a point 241 and the area A2 is separated from the power system. In this case, the system control device 221 requests the measurement devices 231 in the areas A1, A3, and A4 to report power information in detail temporarily. The measuring device 231 in the area A2 observes the change in the power value at the sampling rate converted by the A / D converter 32 (that is, at a short time interval) and performs voltage control of the SVR 9 based on the change.

  According to the present embodiment, even when an abnormality such as a disaster occurs and a part of the area of the power system is divided, the power system in the area where the abnormality does not occur can be stably maintained. .

  According to the present invention, the voltage of the customer 7 can be kept within an allowable range in an area separated from the power system.

  The above-described embodiments of the present invention are examples for explaining the present invention, and are not intended to limit the scope of the present invention only to those embodiments. Those skilled in the art can implement the present invention in various other modes without departing from the gist of the present invention.

For example, this embodiment can be expressed as follows.
"A measuring device that measures the power value, which is a value related to the power between the power system and the customer,
A prediction information receiving unit for receiving prediction information including a predetermined time zone transmitted from another device via the communication path;
A measurement unit for measuring the power value at a predetermined cycle;
The power value measured by the measurement unit is transmitted in a first period in the predetermined time period included in the prediction information, and a second period longer than the first period except in the predetermined time period A power value transmitter for transmitting by,
A measuring device comprising: "

DESCRIPTION OF SYMBOLS 1 ... Electric power system control system, 4 ... System control apparatus, 6 ... PV power generator, 7 ... Consumer, 8 ... Measuring apparatus, 9 ... SVR

Claims (7)

A power system control system for controlling a power system that supplies power to a consumer,
A measuring device that measures the power value generated or consumed by the consumer, and generates power information including the power value;
A system controller capable of controlling the measuring device and the power system;
A communication path that enables information transmission between the measurement device and the system control device;
With
The system controller is
A power information receiving unit that receives power information transmitted from each measuring device via the communication path;
Based on the plurality of received power information, a prediction unit that predicts a customer and a time zone in which a power value changes by a predetermined magnitude or more, and generates prediction information including the predicted time zone;
A prediction information transmission unit that transmits the prediction information to each measurement device in a prediction area that is an area where the predicted consumer exists,
With
The measuring device is
A measurement unit for measuring the power value at predetermined time intervals;
A prediction information receiving unit that receives the prediction information transmitted from the system control device;
Based on the prediction information, it is determined whether power information should be transmitted at a first time interval or a second time interval longer than the first time interval, and the measurement is performed at the determined time interval. A power information transmission unit that transmits the power information including the power value measured by the unit to the system control device;
A power system control system comprising: The power information transmission unit provided in the measurement device,
2. The power system control system according to claim 1, wherein during the time period included in the prediction information, it is determined to transmit the power information to the system control device at the first time interval. A voltage regulator capable of adjusting the voltage of power supplied to consumers; and a solar power generator capable of generating power when receiving sunlight, and supplying the generated power to the power system,
The system controller is
Based on the power information transmitted from the measurement device at the first time interval, a voltage control unit that controls the voltage regulator so that the voltage of power supplied to the consumer does not deviate from a predetermined range. The power system control system according to claim 2, further comprising: The prediction unit provided in the system control device,
Based on a plurality of power information in the past time zone, by analyzing the temporal transition of the area where there is a customer whose power value has changed more than a predetermined magnitude, the power value will become more than a predetermined magnitude in the future The power system control system according to claim 3, wherein prediction information is generated by predicting a changing customer and a time zone. In the system control device,
The prediction information transmitting unit
The power system control system according to any one of claims 1 to 4, wherein the prediction information is transmitted also to each measurement device in each area adjacent to the prediction area. The prediction information transmission unit provided in the system control device,
The power system control system according to any one of claims 1 to 5, wherein the prediction information is transmitted in a broadcast type to each measuring device existing in the prediction area. A power system control method for controlling a power system that supplies power to a consumer,
A measuring device that measures the power value generated or consumed by the consumer, and generates power information including the power value;
A system control device capable of controlling the measuring device and the power system;
A communication path that enables information transmission between the measurement device and the system control device;
With
The system controller is
The power information transmitted from each measuring device is received via the communication path,
Based on the received plurality of power information, predicting a customer and a time zone in which the power value will change by a predetermined magnitude or more in the future, and generating prediction information including the predicted time zone,
Sending the prediction information to each measuring device in the prediction area, which is an area where the predicted customer exists,
The measuring device is
Measure the power value at predetermined time intervals,
Receiving the prediction information transmitted from the system control device;
Based on the prediction information, it is determined whether transmission should be performed at a time interval of the first time interval or the second period longer than the first time interval, and the measurement unit performs the determination at the determined time interval. Transmitting power information including the measured power value to the system control device;
Power system control method.

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