JP6113604B2 - Power supply monitoring and control device - Google Patents

Description

  The present invention relates to a power supply monitoring and control apparatus.

  Traditionally, the main source of power supply in the power system was a large generator linked to the main system. In many cases, there is an organization that mainly operates the power system, and the organization has been systematically proceeding with the construction plan of the power generation facility and the transmission facility.

  However, in the future, large-scale introduction of small and medium-sized generators called distributed power sources that use renewable energy typified by sunlight and wind power is expected. In this case, there is a high possibility that small and medium-sized power generation companies will be disturbed, and there is an increase in uncertainty regarding the expansion and abolition of power generation facilities. Therefore, if a large number of distributed power sources are connected to the power system, it will be difficult to systematically advance or abolish power generation facilities as in the past.

  Such a change in the power supply configuration affects the operation method of the power system. In the operation of the old power system, the supply-demand balance was maintained mainly by controlling large generators. However, as distributed power sources such as renewable energy are widely used in electric power systems, such conventional system operation methods are also required to be reviewed (Patent Document 1).

JP 2007-60742 A

  In order to maintain the power system stably, it is necessary to maintain the frequency within an appropriate range. Frequency maintenance is organized by the balance between supply and demand in the entire power system. If the supply is excessive, a part of the surplus becomes rotational energy of the generator, leading to an increase in the frequency of the power system. Conversely, when the demand is excessive, the frequency decreases.

  In current power system operation, measures are taken to eliminate such a fluctuation in supply and demand balance by combining a plurality of control systems. The control system is broadly divided into an autonomous control mode (Governor-Free operation, hereinafter abbreviated as GF), load frequency control (hereinafter abbreviated as LFC), and economy based on demand forecast. Examples include load distribution control (Economic Load Dispatching Control, hereinafter abbreviated as ELD).

  However, at present, most of the distributed power sources including the renewable energy power source are not controlled for the above-described conventional system operation. Such a distributed power source generally does not have a function for maintaining a frequency like GF or LFC.

  As the number of distributed power sources that do not contribute to grid operation increases, it becomes difficult to maintain the power grid by the conventional grid operation method. Regarding frequency maintenance, the demand for output adjustment borne by large power plants such as thermal power generation becomes severe. Frequent and extensive power adjustment requirements for large power plants result in increased fuel costs and economic losses. In addition, when the limit of the adjustment capacity of a large power plant is exceeded, there may be a frequency deviation and the system maintenance may be hindered.

  Therefore, the idea of contributing to system operation is also discussed for distributed power sources. For example, Patent Document 1 proposes to provide a control network in which a distributed power supply autonomously adjusts the output. In patent document 1, the operation | movement which each distributed power supply tries to eliminate the supply-and-demand imbalance with respect to a frequency fluctuation is implement | achieved.

  However, the attempt of Patent Document 1 targets a power system in a relatively small specific area, and the configuration of the power system is specified in advance. In addition, in Patent Document 1, it is necessary to identify a desired control parameter in advance for supply and demand control necessary for maintaining the frequency. However, in a relatively large-scale power system, it is difficult to accurately grasp the configuration of the entire power system because distributed power sources are added and removed unplanned over a wide range. Therefore, in a relatively large-scale power system, it is difficult and difficult to set desirable control parameters for each distributed power source. On the other hand, in Patent Document 1, it is not considered to actively utilize a distributed power source that increases unintentionally over a wide range.

  The present invention has been made paying attention to the above problems, and its purpose is to monitor and control a power supply that can contribute to stabilization of the power system by adjusting the output of the power supply connected to the power system. Is to provide. A further object of the present invention is to provide a power supply monitoring and control device that calculates an output adjustment amount according to the system frequency for a fluctuation cycle of the system frequency determined as an output adjustment target, and can adjust the output of the power supply. There is.

  In order to solve the above problems, a power supply monitoring and control apparatus according to the present invention monitors and controls a power supply connected to a power system, and is an adjustment that is a fluctuation cycle of a system frequency that is a target of power supply output adjustment. Using the adjustment target fluctuation period determining means for determining the target fluctuation period, the determined adjustment target fluctuation period and the system frequency, the output adjustment amount for adjusting the output of the power source is determined, and the determined output adjustment amount is supplied to the power source. And an output adjustment amount determining means for adjusting the output of the power supply, and a communication means for transmitting the determined adjustment target variation period via the communication network.

  According to the present invention, the monitoring and control apparatus can adjust the output of the power supply with the output adjustment amount determined by the determined adjustment target fluctuation period and the system frequency. As a result, it is possible to construct a control system in which the power supply autonomously contributes to maintaining the frequency of the entire power system.

2 shows an example of a functional configuration of a monitoring control device according to an embodiment of the present invention. It is explanatory drawing which shows the example of installation of the monitoring control apparatus. It is a control block diagram of an output adjustment amount determination means. It is a conceptual diagram of the control system for the frequency adjustment of an electric power system. It is a graph which shows the example of an analysis of the change period about the time series change of a frequency deviation. It is explanatory drawing which shows the structural example of the operation information database of the monitoring control apparatus which a server manages. It is explanatory drawing which shows the example of a condition display regarding the frequency adjustment capability of an electric power grid | system. It is explanatory drawing which shows the structural example of the operation | movement history table of the distributed power source which a monitoring control apparatus manages. It is explanatory drawing which shows the example of the reward delivery system regarding the assignment of the responsibility which adjusts the frequency of an electric power grid | system.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As will be described later, the supervisory control device according to the present embodiment determines a fluctuation cycle of the system frequency (fluctuation cycle to be adjusted) that is handled by a power source that is connected to the power system, and the determined fluctuation cycle and its own system The output adjustment amount is determined according to the frequency, and the output from the power source is adjusted by the output adjustment amount. Thereby, the power supply autonomously participates in the frequency maintenance of the entire power system. Therefore, by using the monitoring control device for each distributed power source, each distributed power source can contribute to the maintenance of the system frequency with respect to each adjustment target variation period. As a result, each distributed power source can fulfill its responsibility for frequency stability of the entire power system, and can reduce the burden of supply and demand adjustment for large generators.

  A method for monitoring and controlling a distributed power source connected to an electric power system using the monitoring control apparatus according to the present embodiment will be described. These distributed power sources are not included in high-frequency monitoring and control via a dedicated communication network like large generators. On the other hand, these distributed power sources have a function of communicating via a public communication network. Therefore, the monitoring control device contributes to frequency adjustment of the entire power system by monitoring and controlling the distributed power source using the communication function.

  FIG. 1 is an example of a functional configuration of a distributed power supply monitoring and control apparatus 0100. The monitoring control device 0100 includes, for example, a system frequency detection unit 0101, a frequency history database 0102, an output adjustment amount determination unit 0103, an adjustment target variation period determination unit 0104, a power supply characteristic database 0105, and a communication unit 0106. The monitoring control device 0100 can be configured as, for example, a computer device having a microprocessor, a main storage device, an auxiliary storage device, a communication circuit, an input / output circuit (all not shown), and the like. Various functions shown in FIG. 1 can be realized by the microprocessor executing a predetermined computer program. A dedicated hardware circuit may be used instead of the computer program.

  First, the outline of the operation of the monitoring control apparatus 0100 will be described with reference to FIG. The system frequency detection means 0101 detects the system frequency of the power system 0201 (both see FIG. 2) connected to the distributed power source 0202. The detected system frequency is stored in the frequency history database 0102 and also output to the output adjustment amount determining means 0103. The output adjustment amount determination unit 0103 calculates the output adjustment amount of the distributed power source and issues a command to the distributed power source. When calculating the output adjustment amount, the output adjustment amount determination unit 0103 obtains the parameters of the calculation formula from the adjustment target variation period determination unit 0104.

  The adjustment target variation period determining unit 0104 is based on the reference processing of the frequency history database 0102 and the power supply characteristic database 0105, and is based on transmission / reception processing with the external communication network 0204 having a scale equivalent to the power system via the communication unit 0106. Then, the parameter of the calculation formula is determined.

  FIG. 2 shows an example in which the monitoring control device 0100 is installed in a power supply 0202 that is connected to the power system 0201. A plurality of distributed power sources 0202 and a large generator 0203 are linked to the power system 0201.

  The monitoring control device 0100 is connected to one or a plurality of distributed power supplies 0202, and monitors and controls the connection-target distributed power supply 0202 as a monitoring control target. The monitoring control device 0100 has a function of communicating with a server 0205 installed remotely via the public communication network 0204. The server 0205 is an example of an “arithmetic apparatus”. The server 0205 is configured as a computer device including, for example, a microprocessor, a main storage device, an auxiliary storage device, an input device, an output device, and the like. The power system operation manager indicates the adjustment status of the system frequency for the power system 0201. Etc. can be presented.

  Hereinafter, the details of the processing procedure of the monitoring control apparatus 0100 described above will be described with reference to FIG. The system frequency detection unit 0101 is a process of calculating a system frequency using a measurement value of a voltage sensor or a current sensor connected to the power system 0201 and outputting the calculated system frequency as commonly used technology. is there.

  The output adjustment amount determination unit 0103 uses a control block as shown in FIG. 3, for example. In FIG. 3, a system frequency deviation (Δf) 0301 is a difference between the system frequency detected by the system frequency detection means 0101 and the commercial rated frequency. The output adjustment amount determination unit 0103 passes the system frequency deviation 0301 through the band-pass filter 0302 and outputs the output adjustment amount (1) under the constraints of the upper limit (UL) 0304 and the lower limit (LL) 0305 by the first-order lag element 0303. ΔP) 0306 is calculated.

  The target output value of the distributed power source 0202 is obtained by adding this output adjustment amount (ΔP) to the current power generation output value of the distributed power source 0202. The operation content of the bandpass filter 0302 is designated by a lower limit fluctuation period TL, a center fluctuation period T0, and an upper limit fluctuation period TH as shown as a parameter group 0307. The monitoring control device 0100 has a mechanism for dynamically determining the parameter 0307 of the bandpass filter 0302 according to the adjustment target fluctuation period determined by the adjustment target fluctuation period determining unit 0104.

  Next, an outline of the adjustment target variation period determining unit 0104 will be described. FIG. 4 shows a concept of a control system for frequency adjustment of the power system 0201. A horizontal axis 0401 indicates a fluctuation cycle related to demand fluctuation occurring in the power system 0201. The vertical axis 0402 indicates the magnitude of the demand fluctuation component. In general, the fluctuation component in a short fluctuation cycle is small, and the fluctuation component increases as the fluctuation cycle increases up to a cycle corresponding to one day. It is known that this relationship tends to be close to an exponential function as shown in FIG.

  The monitoring control apparatus 0100 of the present embodiment incorporates a control system in which the fluctuation cycle is divided into several parts for such fluctuation component characteristics. However, no specific control system has been established for the minute fluctuation component in the region 0403 at present. This is because it is considered that damping is performed according to the frequency characteristics of the demand itself. The other areas 0404, 0405, and 0406 are eliminated by combining a plurality of control systems.

  For short cycle fluctuation components in the area 0404, GF control known as a speed control function of the large generator 0203 is prepared. Each generator output has a drooping characteristic with respect to the frequency observed at the generator end, suppresses the generator output with respect to the frequency increase, and increases the power generation output with respect to the frequency decrease. Since GF control is control using only observation information in each generator, autonomous high-speed control can be realized. Since the speed control function is mechanically limited, the GF control is generally responsible for frequency fluctuations of about several tens of seconds.

  An LFC is prepared for the medium cycle fluctuation component in the area 0405. In LFC, a control system for changing a target output from a central control station to a large generator 0203 is assembled. In general, in LFC, frequency fluctuations of about several minutes to several tens of minutes due to restrictions on the communication speed of the communication network connecting the central control station and the large generator 0203 and restrictions on the change speed of the generator output adjustment. The generator output is adjusted to

  Economic load distribution control (ELD) is prepared for the long period fluctuation component in the area 0406. ELD commands output distribution to the large generator 0203 based on demand prediction for large demand changes that cannot be resolved by LFC. The adjustment target variation period determining unit 0104 determines a parameter group 0307 of the bandpass filter 0302 on the premise of such a control system GF, LFC, and ELD for frequency adjustment.

  The process of the adjustment target variation period determining unit 0104 will be described. First, the adjustment target fluctuation period determining unit 0104 refers to the frequency history database 0102 to obtain time series fluctuations of frequency deviations that have occurred within a certain past time. In addition, as shown in FIG. 5, the adjustment target variation period determining unit 0104 includes sections 1 to N (center variation periods Tc1 to TcN) divided for each fixed range of the variation period 0501 with respect to the time series variation of the frequency deviation. The magnitude 0503 of the actual supply and demand fluctuation 0502 in each of the above is obtained.

  Then, the adjustment target fluctuation cycle determining unit 0104 selects a section probabilistically at regular intervals according to the magnitude of the actual supply and demand fluctuation for each section. As an example, the adjustment target fluctuation cycle determination unit 0104 selects a section using a random number at regular intervals so that the larger the actual supply-demand fluctuation magnitude 0503 is, the more the section is selected.

  The adjustment target fluctuation period determining unit 0104 determines the lower limit fluctuation period TL, the central fluctuation period T0, and the upper limit fluctuation period TH as the parameter 0307 of the bandpass filter 0302 from the center fluctuation period and the upper and lower limit values of the selected section. . However, at this time, the adjustment target fluctuation cycle determining unit 0104 refers to the power supply characteristic database 0105 so that the upper and lower limits of the fluctuation cycle separately designated for each power source 0202 are not exceeded.

  The operation status of the monitoring control device 0100 is collected in the server 0205 via the communication network 0204. FIG. 6 is a configuration example of a database for managing the operation information of the power supply 0202 collected from the monitoring control device 0100 by the server 0205. A target ID is assigned for each power supply of each monitoring control target, and this is stored in column 0601 as an index.

  For each power source 0202 to be monitored and controlled, the center variation period T0 determined by the adjustment target variation period determining unit 0104 is in column 0602, the adjustable amount upper limit 0304 of each power source 0202 is in column 0603, and the adjustable amount lower limit. In this configuration, 0305 is stored in column 0604, respectively.

  With the function of collecting and managing the operation information described above, the server 0205 can monitor the frequency adjustment capability of the entire power system. FIG. 7 is an example of a status display regarding the frequency adjustment capability of the power system 0201. The screen illustrated in FIG. 7 can be output to an output device (display, printer, or the like) included in the server 0205.

  The horizontal axis 0701 of the graph indicates the fluctuation cycle of the supply and demand balance. The vertical axis 0702 of the graph indicates the magnitude of supply and demand fluctuation assumed for each fluctuation cycle. As described in the operation information database of FIG. 6, the frequency adjustment capability of each distributed power supply 0202 is represented by a white square using values collected from the monitoring control device 0100 of each distributed power supply 0202. A region 0703 is drawn.

  In the graph of FIG. 7, an area 0704 represented by a rectangle filled with diagonal lines is drawn with respect to the frequency adjustment capability of the large generator 0203 as well as the frequency adjustment capability of the distributed power source 0202. The frequency adjustment capability of the entire power system is shown by the accumulation of the frequency adjustment capability by the distributed power source 0202 and the frequency adjustment capability by the large generator 0203.

  Further, in FIG. 7, the central reference 0705, the upper limit 0706, and the lower limit 0707 of the separately designated frequency adjustment capability are displayed together so that the operation manager of the power system can determine whether the current frequency adjustment capability is appropriate in the server 0205. It is possible to judge. The operation manager of the power system can use the screen shown in FIG. 7 as support information in the operation of the large generator 0203 by the distributed power source 0202.

  On the other hand, it is necessary to quantify the contribution of the distributed power supply 0202 that cooperated with the frequency adjustment of the entire power system. FIG. 8 is an example of a table for managing the operation history of the distributed power source 0202 controlled by the monitoring control device 0100.

  For each time stored in column 0801, information on adjustment target variation period T0 stored in column 802, information on lower limit LL of the adjustable amount stored in column 0803, and adjustable amount stored in column 0804 The upper limit UL information is recorded. The distributed power supply operation history table shown in FIG. 8 records how much each of the distributed power supplies 0202 has provided the frequency adjustment capability to the power system as a reserve while losing power generation opportunities.

  Finally, the business structure related to the operator of the distributed power source 0202 will be described. FIG. 9 is an example of a reward giving / receiving system related to sharing of frequency adjustment duties. Here, the power system operator 0901 is responsible for the operation responsibility of the commercial power system. On the other hand, the distributed power source 0202 that is a monitoring control target of the monitoring control device 0100 is owned by a power operator 0902 that is another business operator.

  First, after connecting the distributed power source 0202 to the commercial power system 0201, the power operator 0902 makes an application 0903 to participate in a system for distributing the responsibility for frequency adjustment. When the examination of the application content is completed, the monitoring control device 0100 of the distributed power source 0202 periodically reports the operation status 0904 as shown in FIG. 8 to the server 0205 to the power system operator 0901.

  The server 0205 periodically collects the operating status of each distributed power source 0202 from each monitoring control device 0100 via the communication network 0204. The power system operator 0901 provides a reward 0905 to the distributed power source operator 0902 as a post-settlement after repeating the process of reporting the operation status 0904 to the server 0205 from time to time.

  There are various methods for calculating the reward. For example, the value [¥ / kW] of reserve capacity for frequency adjustment is agreed in advance for each time zone, and the adjustment provided by each distributed power supply 0202 for frequency adjustment in practice. A business structure that pays money according to the range of the upper and lower limits of the possible amount.

  By constructing the business structure as described with reference to FIG. 9, this embodiment can also provide an environment for improving the business balance of the distributed power source 0202.

  Since the present embodiment has the above-described configuration, the monitoring control device 0100 can adjust the output of the distributed power source 0202 under its management according to the difference between the adjustment target fluctuation period and the system frequency, and as a result, The distributed power source 0202 can autonomously participate in maintaining the frequency of the entire power system.

  In this embodiment, each distributed power supply 0202 is not configured to adjust its output in response to an instruction from the server 0205, but is information that the monitoring control device 0100 associated with each distributed power supply 0202 measures by itself. Based on the above, the fluctuation period to be adjusted is autonomously selected, and the output of the distributed power source 0202 is adjusted according to the difference between the selected fluctuation period and the system frequency. Therefore, even in a relatively large-scale power system 0201 in which a relatively large number of distributed power supplies 0202 are interconnected and the specific configuration changes as needed, the distributed power supplies 0202 can contribute to maintaining the system frequency.

  In the present embodiment, as shown in FIG. 5, with respect to the time series fluctuation of the frequency deviation, the magnitude of the actual supply and demand fluctuation in each of the sections divided for each constant range of the fluctuation period 0501 is obtained, and according to the magnitude, a certain time is obtained. Each section is selected probabilistically. Therefore, the fluctuation cycle to be adjusted by each distributed power source 0202 can be selected relatively appropriately for the entire distributed power source 0202 without depending on an instruction from the server 0205. Thereby, it is possible to simplify the control structure and contribute to the maintenance of the system frequency in the large-scale power system 0201 whose configuration varies daily.

  In the present embodiment, the efficiency of the entire power system can be increased in accordance with the spread of the distributed power source 0202, which can contribute to the promotion of the spread of the distributed power source 0202.

  In addition, this invention is not limited to embodiment mentioned above. A person skilled in the art can make various additions and changes within the scope of the present invention.

  0201: Power system, 0202: Power supply, 0203: Large generator, 0204: Communication network, 0205: Server, 0100: Monitoring control device, 0101: System frequency detection means, 0102: Frequency history database, 0103: Output adjustment amount determination means 0104: Adjustment target variation period determining means, 0105: Power supply characteristic database, 0106: Communication means

Claims (6)

In the power supply monitoring and control system linked to the power system,
An adjustment target fluctuation period determining means for determining an adjustment target fluctuation period that is a fluctuation period of a system frequency to be an output adjustment target of the power source;
The output adjustment amount for adjusting the output of the power supply is determined using the determined adjustment target fluctuation period and the system frequency, and the determined output adjustment amount is input to the power supply to adjust the output of the power supply Output adjustment amount determining means to
Communication means for transmitting the determined adjustment target variation period via a communication network;
Equipped with a,
The adjustment target fluctuation cycle determining means divides the fluctuation cycle of the system frequency into a plurality of sections, and based on the magnitude of the fluctuation amount of the system frequency and a random number in each section, any one of the sections select, monitoring and control device of the power supply characterized that you determine the fluctuation period corresponding to the selected segment as the adjustment target change period. In the power supply monitoring and control device according to claim 1,
The output adjustment amount determining means is a power supply monitoring and control apparatus that determines the output adjustment amount using an arithmetic expression for inputting a deviation between the system frequency and a preset reference frequency. In the power supply monitoring and control device according to claim 1,
The adjustment target fluctuation cycle determining unit is a power supply monitoring and control device that determines the adjustment target fluctuation period from a result of an operation for decomposing time series changes of the system frequency into fluctuation period components. In the power supply monitoring and control device according to claim 1,
The communication means is a power supply monitoring and control device that transmits the adjustment target variation period to an arithmetic device having a function of accumulating reception histories from one or more monitoring and control devices. In the power supply monitoring and control device according to claim 1,
The communication means is a power supply monitoring and control device that transmits the adjustment target fluctuation period to a computing device having a function of displaying the received content from one or more monitoring and control devices on a screen. In the power supply monitoring and control device according to claim 1,
The communication means transmits the adjustment target variation period to an arithmetic device having a function of quantifying a reward amount that contributes to frequency adjustment of the entire power system according to a reception history from one or more monitoring control devices. Power supply monitoring and control device.

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