Power monitoring and control device

Abstract

To suppress a decrease in the acquisition success rate of acquiring power information from a smart meter at certain communication intervals due to communication failures, and maintains the accuracy of load following control.SOLUTION: In wireless communication control in which power information is acquired through route B communication from a smart meter 36 at communication intervals of each fixed time (for example, 30 seconds), the operating status of the smart meter 36 is checked at the communication intervals of each fixed time, and when the route B communication is not possible, it is put into a standby state, and when the route B communication is possible, a route B transmission request function 50A is activated. If the standby state continues for a certain period of time (30 seconds), for control purposes, by assuming that the power information has been acquired, communication will not fail and no penalty (for example, 60 seconds of waiting) will be applied, and communication every 30 seconds can be continued.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a power monitoring and control device that acquires power information such as current, power, and power amount required for operation control of distributed power generation facilities, for example, a household fuel cell cogeneration system. [Background technology]

[0002] In homes that are equipped with distributed power sources, such as solar panels, storage batteries, or cogeneration systems that generate electricity using gas engines or fuel cells and utilize exhaust heat in addition to commercial power sources, it is important to monitor overcurrents and reverse currents.

[0003] In conventional home power generation systems, a CT (Current Transformer) clamp is attached to the distribution panel inside the home to acquire the home's power load and perform load following control (hereinafter referred to as the wired system).

[0004] On the other hand, there are wireless methods such as using wireless CTs and remotely obtaining the power load from the power information of a smart electricity meter. Wired methods have the disadvantage of requiring CT wiring work and the cost of drilling holes in the exterior wall, so wireless methods are desired.

[0005] Patent Document 1 describes the provision of a distribution board that can prevent the board from becoming large even when it accommodates devices that manage both power usage data for branch electric lines and power amount data from a smart meter.

[0006] The power information transmission unit installed in the distribution board communicates with the smart meter via route B using either G3PLC or Wi-SUN wireless communication, but the relationship between the power information transmission unit and the distributed power generation equipment is not described.

[0007] Patent Document 2 describes how power information is obtained from a smart meter via the Route B communication path, which roughly tracks the ever-changing power usage in a home, enabling control that approximates the power transition characteristics of a home.

[0008] The smart meter has three communication routes for acquiring information: Route A, Route B, and Route C. Route A is the communication route connecting the smart meter and the electric power company, Route B is the communication route connecting the smart meter and the HEMS, etc., and Route C is the communication route for providing the data acquired by the electric power company via Route A to a third party (such as a retail electricity supplier). [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-075895 [Patent Document 2] Japanese Patent Publication No. 2021-164198 Summary of the Invention [Problem to be solved by the invention]

[0010] However, Route B and specified low-power radio communications have limitations on communication frequency based on various standards to avoid radio interference with other devices and ensure the processing speed of smart meters and HEMS (Home Energy Management Systems). Therefore, an example of the default communication interval for obtaining power and current information from smart meters via wireless communication (specified low-power radio, Wi-SUN / Route B) is once every 30 seconds. If power and current information can be obtained at intervals of about 30 seconds, it will be possible to control power generation according to the power consumed in a home.

[0011] On the other hand, communication may fail due to an update of the smart meter's program or due to overlapping with communications between other devices (route A communications, route B communications with other devices (HEMS, etc.), and specific low-power radio communications of other devices) (hereinafter collectively referred to as a communication failure).

[0012] If communication fails, a timeout must be set until the next data request depending on the number of data requests due to radio wave interference or communication standby control (carrier sense) to avoid radio wave interference. For example, if two pieces of data (power and voltage) are requested and communication fails, communication will be cut off for 60 seconds.

[0013] This reduces the opportunities to obtain power information at fixed communication intervals, which poses a problem of reduced accuracy in load following control.

[0014] The present invention aims to provide a power monitoring and control device that can suppress a decrease in the success rate of obtaining power information from a smart meter at a fixed communication interval due to communication failures and maintain the accuracy of load following control. [Means for solving the problem]

[0015] The power monitoring control device of the present invention is a power monitoring control device for a distributed power supply facility that acquires information on the power consumed in a house from a smart meter connected to a power feed line for drawing commercial power into the house, and has: a communication unit that executes communication with the smart meter over a specified communication path when communication is possible at each communication period of a specified communication interval to acquire power information; an acquisition unit that acquires the operating status of the smart meter before communication by the communication unit at each communication period; a judgment unit that determines whether communication over the specified communication path by the communication unit is possible based on the operating status of the smart meter acquired by the acquisition unit; and a communication delay unit that, if the judgment unit determines that communication is not possible, automatically puts the communication of the communication unit into a standby state until it determines that communication is possible.

[0016] According to the present invention, the communication unit communicates with the smart meter via a specified communication path to obtain power information when communication is possible at each communication period of a specified communication interval, and the acquisition unit acquires the operating status of the smart meter at each communication period before communication by the communication unit.

[0017] The determination unit determines whether or not communication via the predetermined communication path by the communication unit is possible based on the operating status of the smart meter acquired by the acquisition unit.

[0018] When the determining unit determines that communication is not possible, the communication delay unit voluntarily puts the communication unit into a standby state until it determines that communication is possible.

[0019] This makes it possible to suppress a decrease in the success rate of acquiring power information from smart meters at fixed communication intervals due to communication failures, and maintain the accuracy of load following control.

[0020] In the present invention, after the communication delay unit has entered a standby state, the time when communication for acquiring the power information is executed is set as the starting point of the subsequent communication interval.

[0021] It becomes possible to obtain power information at stable communication intervals during time periods when communication is not unavailable.

[0022] In addition, in the present invention, the communication unit has a carrier sense function that checks the communication congestion status for the smart meter to obtain the power information based on the specified communication path, and if it determines that the communication is busy, cuts off communication for a period longer than the communication interval, and if the next communication time based on the specified communication interval arrives while the communication delay unit is waiting, it is assumed that the communication unit before waiting had successfully obtained the power information via the specified communication path, thereby avoiding communication interruption at the next communication time due to communication failure.

[0023] It is possible to avoid communication interruptions for periods longer than the communication interval due to communication failure, and it is possible to obtain power information at a predetermined communication interval. [Effects of the Invention]

[0024] According to the present invention, it is possible to suppress a decrease in the success rate of obtaining power information from a smart meter at a fixed communication interval due to communication failure, and to maintain the power contribution rate for load following control. [Brief explanation of the drawings]

[0025] [Figure 1] 1 is a schematic diagram of a cogeneration system according to an embodiment of the present invention and a house in which the cogeneration system is installed. [Figure 2] FIG. 2 is a control block diagram of a controller of the cogeneration system according to the present embodiment. [Figure 3] FIG. 2 is a functional block diagram for controlling the communication frequency assurance of the communication interval in the controller of the cogeneration system according to the present embodiment. [Figure 4] 4 is a flowchart showing a communication interval adjustment control routine executed by a controller of the cogeneration system according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0026] FIG. 1 shows a schematic diagram of a household fuel cell cogeneration system according to this embodiment (hereinafter, in this embodiment, simply referred to as "cogeneration system 10").

[0027] The cogeneration system 10 is a system in which a tank unit and a fuel cell unit are installed side by side. Note that "side by side" does not necessarily mean that they are physically adjacent to each other, but rather that they are interconnected. In other words, the tank unit and the fuel cell unit may be installed separately and connected by piping, electrical wiring, etc.

[0028] As shown in FIG. 1, the cogeneration system 10 is installed along the outer wall of a house 12, and workers go to the site to carry out the installation work.

[0029] FIG. 1 shows a state in which the installation work has been completed, the test run has been completed, and the system is ready for steady operation in cooperation with various facilities (electrical equipment, hot water supply facilities, etc.) in the house 12.

[0030] (Configuration of cogeneration system 10) Although not shown, the cogeneration system 10 includes a hot module, a power conditioner, an exhaust heat recovery device, a heat storage tank, a radiator, a heat exchanger, etc., each of which is controlled in cooperation with each other by the controller 14 via a hot water supply-related control unit 27 and a power generation-related control unit 29 (both see Figure 2).

[0031] The hot module extracts hydrogen in a fuel processor, supplies the extracted hydrogen to a fuel cell stack, and generates DC power using oxygen in the air.

[0032] The power conditioner converts the generated DC power into AC power and supplies it to the house.

[0033] The exhaust heat recovery device recovers heat from the exhaust gas generated by power generation.

[0034] The heat storage tank can store the heat recovered via the heat medium at a high temperature, and the stored heat is used to supply hot water.

[0035] The radiator dissipates heat and cools the heat transfer medium, but the radiator is not essential.

[0036] The heat exchanger uses the high-temperature heat medium from the heat medium tank to heat the tap water. The heat exchanger is not essential.

[0037] The cogeneration system 10 can also send the generated power to a heat source machine 16 via a power line 15. The heat source machine 16 further heats the hot water heated by the cogeneration system 10 by burning city gas (e.g., 13A) as needed and supplies the water to the house 12.

[0038] As shown in FIG. 2, the controller 14 includes a microcomputer 28 that is configured from a CPU 18, a RAM 20, a ROM 22, an I / O 24, and a bus 26 such as a data bus or a control bus that connects these components.

[0039] A hot water supply related control section 27 and a power generation related control section 29 are connected to the I / O 24, and operations relating to hot water supply and power generation are controlled by the controller 14.

[0040] In addition, a large-scale storage device 30 is connected to the I / O 24, which stores processing programs related to power generation and hot water supply executed by the controller 14, as well as historical information based on power generation (for example, in this embodiment, communication interval adjustment information, etc.).

[0041] Furthermore, a remote control 32 is connected to the I / O 24. The remote control 32 is installed inside the house 12 in which the cogeneration system 10 is to be installed, and has functions such as allowing a user to input commands regarding the cogeneration system 10 (and the heat source machine 16) and displaying the status of the cogeneration system 10.

[0042] As shown in FIG. 1, in the distributed power supply system according to this embodiment, power purchased from a commercial power supply 34 and power generated by a cogeneration system 10 are used as power sources for a house 12.

[0043] The commercial power supply 34 is connected to a smart meter 36. The smart meter 36 measures power information such as the current, power, and power consumption of the commercial power supply 34, and can transmit the measured information to a specific communication destination via communication paths A, B, and C.

[0044] That is, route A is a communication path connecting the smart meter 36 and the electric power company, route B is a communication path connecting the smart meter 36 and equipment installed in the house 12 (for example, the controller if a HEMS is installed), and route C is a communication path for providing data acquired by the electric power company via route A to a third party (such as a retail electricity supplier).

[0045] A power line 38 output from the smart meter 36 is wired to a distribution board 40 installed in the house 12 .

[0046] In the distribution board 40, if the smart meter 36 side is considered to be the upstream side, a service breaker 42, an earth leakage breaker 46, and a safety breaker 48 are installed in this order from the upstream side.

[0047] The service breaker 42 is a circuit breaker for determining the contract capacity, but may not be installed.

[0048] The earth leakage breaker 46 is a circuit breaker that quickly detects and cuts off leakage current in the internal wiring or electrical equipment of the house 12, thereby preventing electrical accidents.

[0049] The safety breaker 48 is attached to each branch circuit that transmits power from the distribution board 40 to each point of use in the house 12, and is a circuit breaker that automatically protects the circuit when it detects a short circuit caused by an electrical equipment failure or when power usage above a certain level is detected.

[0050] Here, the electricity generated by the cogeneration system 10 is merged with the commercial power source 34 via a dedicated safety breaker 48A installed in the distribution board 40, and can be used as a power source for electrical equipment inside the house 12.

[0051] Although not shown in the figure, the cogeneration system 10 is provided with a power line dedicated to use in the event of a power outage from the commercial power source 34, so that in a situation where power is not supplied from the commercial power source 34 due to a power outage, the power generated by the cogeneration system 10 can be supplied via a dedicated power outage outlet installed in part of the house 12.

[0052] Here, the controller 14 of the cogeneration system 10 needs to control the generated power in accordance with the amount of power used in the house 12, which varies from moment to moment.

[0053] In this embodiment, the communication interval for obtaining power information from the smart meter 36 via the communication path of Route B is set to once every 30 seconds as a standard. This communication interval allows control to roughly follow the ever-changing power usage in the house 12 without violating various standards for wireless communication.

[0054] Incidentally, the smart meter 36 communicates with the controller 14 of the cogeneration system 10 via route B, as well as other communications such as via route A. There are also periods when the smart meter 36 is unable to perform communications, including updates (while idling).

[0055] Therefore, if the controller 14 of the cogeneration device 10 attempts to obtain power information via the communication path of route B at intervals of once every 30 seconds, there is a possibility that communication to obtain power information will fail due to interference from communications (route A, route B, specific low-power radio) of other devices in the home or a neighboring home, and the communication standby (carrier sense) to avoid interference will exceed the specified number of times.

[0056] In other words, in the controller 14 of the cogeneration system 10, if communication control is limited to obtaining information at a communication interval of once every 30 seconds, there may be occasions when the information cannot be obtained, and it may not be possible to obtain power information at the required frequency.

[0057] Therefore, in this embodiment, the controller 14 of the cogeneration system 10 communicates at intervals of once every 30 seconds, and based on the operating status of the smart meter 36 when acquiring power information via the communication path of Route B, the controller 14 grasps the communication possible period along with the normal communication interval, thereby ensuring communication opportunities at the required frequency.

[0058] 3 is a functional block diagram for controlling the communication frequency of communication intervals in the controller 14 of the cogeneration system 10. Each block in this functional block diagram is classified by function, and in this embodiment, the control is performed as software control in which the CPU 18 operates based on a communication interval adjustment program stored in the ROM 22. Note that the operating programs shown in some or all of the functional blocks may be incorporated into an IC chip such as an ASIC and run on the chip.

[0059] As shown in Figure 3, the wireless communication unit 50 has a function of establishing a communication protocol for acquiring power information via the B-route communication path of the smart meter 36 and requesting transmission (B-route transmission request function 50A and smart meter operation status confirmation function 50B for confirming the current operation status of the smart meter 36).

[0060] The wireless communication unit 50 is connected to an operation status confirmation instruction unit 52. Here, the operation status confirmation instruction unit 52 is connected to a communication interval timer 54, which outputs a trigger signal to the wireless communication unit 50 at regular intervals (30 seconds in this embodiment). Based on this trigger signal, a smart meter operation status confirmation function 50B is activated, and the wireless communication unit 50 checks the operation status of the smart meter 36.

[0061] The wireless communication unit 50 is connected to the communication feasibility determination unit 56. The wireless communication unit 50 sends to the communication feasibility determination unit 56 the smart meter operation status acquired by the smart meter operation status confirmation function 50B.

[0062] The communication availability determination unit 56 determines whether or not it is possible to acquire power information via route B based on the operating status of the smart meter 36, and sends the determination result (communication availability information) to the communication control unit 58.

[0063] (Communication during communication intervals) When communication is possible during normal communication opportunities (communication opportunities at fixed time intervals), the communication control unit 58 outputs a power information acquisition instruction to the wireless communication unit 50 and outputs a reset / start signal to the communication interval timer 54 (in this case, the 30-second communication interval remains unchanged).

[0064] In response to the power information acquisition instruction, the wireless communication unit 50 activates the route B transmission request function 50A and establishes a route B communication protocol with the smart meter 36.

[0065] The wireless communication unit 50 is connected to the power information acquisition unit 60. When a communication protocol is established (successfully) in the route B transmission request function 50A of the wireless communication unit 50, the power information acquisition unit 60 acquires power information from the smart meter 36 via the route B communication path.

[0066] The power information acquisition unit 60 is connected to the system operation control unit 62 and notifies the system operation control unit 62 of the acquired power information.

[0067] The system operation control unit 62 calculates the power generation output and the like based on the acquired power information, and sends a control instruction signal to the necessary control target devices of the cogeneration system 10.

[0068] This allows the cogeneration system 10 to operate with a power generation output that generally matches the power consumption in the house 12.

[0069] (Waiting for communication intervals) On the other hand, if communication is not possible, the communication control unit 58 waits for communication (activation of the route B transmission request function 50A) once every fixed time (30 seconds) by the communication interval timer 54.

[0070] The communication availability determination unit 56 continues to output the communication availability signal to the communication control unit 58 until communication becomes possible or until the next communication time (30 seconds later) arrives.

[0071] Here, when the communication control unit 58 receives a communication possible signal while waiting for communication, it outputs a power information acquisition instruction to the wireless communication unit 50 at that time, and also outputs a reset start signal to the communication interval timer 54.

[0072] Furthermore, if the next communication time arrives while waiting for communication, the power information could not be obtained at this communication opportunity, but for control purposes it is assumed that the power information has been obtained, and the above process (activating the smart meter operation status confirmation function 50B at the next communication opportunity (30 seconds later)) will be repeated in the next communication interval timer 54.

[0073] From a control perspective, since the power information is considered to have been acquired, communication does not fail, and therefore no penalty (for example, a 60-second wait) is imposed, and communication continues every 30 seconds.

[0074] In this embodiment, in addition to requesting power information from the smart meter 36, if a B route communication unavailable state (A route communication in progress, update in progress, or other communication unavailable state such as idling) transmitted from the smart meter 36 is detected, the smart meter 36 will voluntarily wait for a power information request from the smart meter 36.

[0075] When it is determined that route B communication is possible, the power information request is resumed at the normal communication interval. This improves the communication success rate by ensuring that power is obtained only when there is a high probability that the power information request will be successful.

[0076] The operation of this embodiment will be described below with reference to the flowchart of FIG.

[0077] FIG. 4 is a flowchart showing a communication interval adjustment control routine executed by the controller 14 of the cogeneration system 10.

[0078] In step 100, the default value of the communication interval (in this embodiment, once every 30 seconds) is read, and the process proceeds to step .

[0079] In step 102, it is determined whether the communication interval time has elapsed, and step 102 is repeated until the communication interval time has elapsed. If the determination in step 102 is affirmative, the process proceeds to step 104, where the smart meter operation status confirmation function 50B of the wireless communication unit 50 is activated to acquire the operation status of the smart meter 36.

[0080] In the next step 106, it is determined whether or not the B route communication is possible based on the operating status of the smart meter 36.

[0081] If the determination in step 106 is affirmative, the process proceeds to step 108 , where the route B transmission request function 50A of the wireless communication unit 50 is activated to request power information from the smart meter 36 , and the process proceeds to step 110 .

[0082] In step 110, it is determined whether or not the power information has been acquired in response to the request in step 108. If the determination in step 110 is negative, the power information could not be acquired even though the operation status check of the smart meter 36 showed that route B communication was possible, so the process proceeds to step 112, where error processing (for example, reporting failure to acquire power information, recording log information, etc.) is performed, and the process proceeds to step 102.

[0083] Also, if the result of step 110 is affirmative, the process proceeds to step 114, where the operating status of each controlled device is controlled based on the power information, and then the process proceeds to step 116, where the current communication time is set as the starting point for measuring the communication interval (reset / start), and the process returns to step 102, where the above process is repeated.

[0084] On the other hand, if the determination in step 106 is negative, the process proceeds to step 118, where communication standby is started. During the communication standby period, no request for power information is made to the smart meter 36.

[0085] In the next step 120, it is determined whether the communication standby period has reached the default communication interval (specifically, whether 30 seconds have elapsed since the start of standby), and if the determination is negative, the process returns to step 104. That is, if B route communication becomes possible during the standby period (positive determination in step 106), the process proceeds to step 108, and the B route transmission request function 50A is activated.

[0086] If the determination in step 120 is affirmative, the process proceeds to step 122, where the communication is assumed to have been a pseudo success (for control purposes, it is assumed that power information has been acquired), and the process proceeds to step 102.

[0087] According to this embodiment, in wireless communication control, power information is obtained from the smart meter 36 via route B communication at fixed communication intervals (for example, 30 seconds), the operating status of the smart meter 36 is checked at fixed communication intervals, and when route B communication is not possible, the smart meter 36 is put into a standby state, and when route B communication is possible, the route B transmission request function 50A is activated. Furthermore, if the standby state continues for a fixed time (30 seconds), the control considers that power information has been obtained, so that communication does not fail, no penalty (for example, a 60-second wait) is imposed, and communication every 30 seconds can be continued. [Explanation of symbols]

[0088] 10 Cogeneration equipment 12 Houses 14 Controller 15 Power line 16 Heat source machine 18 CPU 20 RAM 22 ROM 24 I / O 26 Bus 27 Hot water supply related control unit 28 Microcomputer 29 Power generation related control section 30 Mass storage 32 Remote Control 34 Commercial power supply 36 Smart Meters 38 Power line 40 Distribution board 42 Service breaker 46 Earth leakage breaker 48 Safety Breaker 48A safety breaker 50 Wireless Communication Unit (Communication Unit) 50A Route B transmission request function 50B Smart meter operation status confirmation function 52 Operation status confirmation instruction section 54 Communication interval timer 56 Communication availability determination unit (determination unit) 58 Communication control section (communication delay section) 60 Power information acquisition unit (acquisition unit) 62 System Operation Control Unit

Claims

1. A power monitoring and control device for distributed power generation equipment that acquires information about power consumed in a house from a smart meter connected to a power lead-in line for drawing commercial power into the house, a communication unit that executes communication with the smart meter via a predetermined communication path to acquire power information when communication is possible at each communication time of a predetermined communication interval; an acquisition unit that acquires, at each communication time, before communication by the communication unit, from the smart meter, operation status information relating to an operation status indicating whether the smart meter is communicating via another communication path, is being updated, or is idling; a determination unit that determines whether communication via the predetermined communication path by the communication unit is possible based on the operation status information of the smart meter acquired by the acquisition unit; and a communication delay unit that, when the determination unit determines that communication is not possible via the predetermined communication path, automatically puts communication of the communication unit into a standby state until it is determined that communication is possible, and, when it determines that communication is possible via the predetermined communication path, requests the power information via the predetermined communication path; A power monitoring and control device having the same.

2. The power monitoring and control device according to claim 1 , wherein the communication delay unit sets a standby state, and then the communication time when the communication for acquiring the power information is executed is set as the starting point of a subsequent communication interval.

Images