Power system and control method

Abstract

To provide a power system capable of suppressing a state in which time stamps added to specific control results become discontinuous, and a control method.SOLUTION: A power system comprises a power storage device which executes specific control for controlling charge and discharge on the basis of a frequency of an electric power system, and a control device which controls the power storage device. The control device stops a time adjustment function on time adjustment for changing a time managed by the control device using a time managed by a time server before the specific control, resumes the time adjustment function after the specific control, and adjusts time stamps added to the specific control results when parameters on the time adjustment meets a specific condition.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a power system and a control method. [Background technology]

[0002] In recent years, technology (e.g., Virtual Power Plant (VPP)) that uses power storage devices as distributed power sources to maintain the balance between power supply and demand in a power grid has become known. In such cases, it is necessary to adjust the frequency of the power grid by reverse flow power supplied from the facility to the power grid (hereinafter, "supply and demand adjustment"). To enable such supply and demand adjustment, a technology has been proposed that divides regulated power sources into categories and transmits an appropriate signal for each category (e.g., Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6183576 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, when a facility is requested to adjust supply and demand by business operators such as an aggregation coordinator (AC) or a resource aggregator (RA), the facility is expected to execute specific control to control a power storage device within the facility based on the frequency of the power grid in response to the supply and demand adjustment request. The facility reports the result of the specific control to the AC or the RA.

[0005] In such a case, the facility needs to synchronize the time using a time server. The time synchronization method may be NTP (Network Time Protocol). For example, the time needs to be synchronized at least once an hour.

[0006] However, if the time is adjusted while the above-described supply and demand adjustment is being performed, the timestamp attached to the result of the specific control may become discontinuous.

[0007] Therefore, the present invention has been made to solve the above-mentioned problems, and aims to provide a power system and a control method that can prevent the situation in which the timestamp attached to the result of specific control becomes discontinuous. [Means for solving the problem]

[0008] One aspect of the disclosure is an electric power system that includes a power storage device that executes specific control to control charging and discharging based on the frequency of a power grid, and a control device that controls the power storage device, wherein the control device stops a time adjustment function related to time adjustment that corrects a time managed by the control device using a time managed by a time server before the specific control, and resumes the time adjustment function after the specific control, and adjusts a timestamp attached to the result of the specific control when a parameter related to the time adjustment satisfies a specific condition.

[0009] One aspect of the disclosure is a power system that includes a power storage device that executes specific control to control charging and discharging based on the frequency of a power grid, and a control device that controls the power storage device, wherein before the specific control, the control device sets the power storage device to stop a time adjustment function related to time adjustment that corrects the time managed by the control device using a time managed by a time server, and after the specific control, sets the power storage device to resume the time adjustment function, and the power storage device adjusts a timestamp attached to the result of the specific control when a parameter related to the time adjustment satisfies a specific condition.

[0010] One aspect of the disclosure is a control method comprising the steps of: a control device that controls a power storage device that executes specific control that controls charging and discharging based on the frequency of a power grid, stopping a time adjustment function related to time adjustment that corrects a time managed by the control device using a time managed by a time server before the specific control; the control device resuming the time adjustment function after the specific control; and the control device adjusting a timestamp attached to a result of the specific control when a parameter related to the time adjustment satisfies a specific condition.

[0011] One aspect of the disclosure is a control method comprising the steps of: a control device that controls an energy storage device that executes specific control that controls charging and discharging based on the frequency of a power grid, setting the energy storage device to stop a time adjustment function related to time adjustment that corrects the time managed by the control device using a time managed by a time server before the specific control; a step of the control device setting the energy storage device to resume the time adjustment function after the specific control; and a step of the energy storage device adjusting a timestamp attached to the result of the specific control when a parameter related to the time adjustment satisfies a specific condition. Effect of the Invention

[0012] According to the present invention, it is possible to provide a power system and a control method that can prevent a situation in which the timestamp attached to the result of specific control becomes discontinuous. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a diagram showing a power management system 1 according to an embodiment. [Diagram 2] FIG. 2 is a diagram showing a facility 100 according to the embodiment. [Diagram 3] FIG. 3 is a diagram showing a power storage device 120 according to an embodiment. [Figure 4] FIG. 4 is a diagram showing the EMS 160 according to the embodiment. [Diagram 5]FIG. 5 is a diagram for explaining frequency fluctuation adjustment according to the embodiment. [Figure 6] FIG. 6 is a diagram for explaining the specific control according to the embodiment. [Figure 7] FIG. 7 is a diagram for explaining option 1 according to the embodiment. [Figure 8] FIG. 8 is a diagram for explaining option 2 according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, the embodiments will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, the drawings are schematic.

[0015] [Embodiment] (Power Management System) A power management system according to an embodiment will be described below. The power management system may be simply referred to as a power system.

[0016] 1, the power management system 1 includes a facility 100. The power management system 1 may include a power management server 200 and a time server 300.

[0017] Here, the facility 100 and the power management server 200 are configured to be able to communicate with each other via a network 11. The network 11 may include the Internet, a dedicated line such as a Virtual Private Network (VPN), or a mobile communication network.

[0018] The facility 100 is connected to the power system 12, and may receive power from the power system 12, or may supply power to the power system 12. Power from the power system 12 to the facility 100 may be referred to as forward flow power, purchased power, or demanded power. Power from the facility 100 to the power system 12 may be referred to as reverse flow power or sold power. In FIG. 1, facilities 100A to 100C are illustrated as examples of the facility 100.

[0019] Although not particularly limited, the facility 100 may be a facility such as a residence, a facility such as a store, or a facility such as an office. The facility 100 may be an apartment building including two or more residences. The facility 100 may be a complex including at least two or more of the following facilities: a residence, a store, and an office. Details of the facility 100 will be described later (see FIG. 2).

[0020] The power management server 200 is managed by a business operator who manages power related to the power system 12. The business operator may be a power generation business operator, a power transmission and distribution business operator, or a retail business operator. The business operator may be a resource aggregator (hereinafter, RA), or an aggregation coordinator (AC) that manages the RA. The RA may be a business operator who adjusts the power supply and demand balance of the power system 12. The adjustment of the power supply and demand balance may include a transaction (hereinafter, negawatt trading) in which reduced power of the demand power (flow power) of the facility 100 is exchanged for value. The adjustment of the power supply and demand balance may include a transaction in which increased power of reverse flow power is exchanged for value. In the VPP, the RA may be a business operator such as a power generation business operator, a power transmission and distribution business operator, or a retail business operator.

[0021] The time server 300 is a server that manages a reference time for performing time adjustment in the power management system 1. Although not particularly limited, the time adjustment method may be NTP (Network Time Protocol). For example, the power storage device 120 or the EMS 160 may perform time adjustment periodically, or may perform time adjustment in response to a request from the power management server 200 (AC or RA). The time adjustment may be performed in a wireless environment based on standards such as IEEE802.11a / b / g / n / ac / ax, ZigBee, Wi-SUN, LTE, 5G, and 6G.

[0022] In the embodiment, communication between the power management server 200 and the EMS 160 is performed according to a first protocol. On the other hand, communication between the EMS 160 and the distributed power source (the solar cell device 110, the power storage device 120, or the fuel cell device 130) is performed according to a second protocol different from the first protocol. For example, the first protocol may be a protocol conforming to Open ADR (Automated Demand Response) or a unique dedicated protocol. For example, the second protocol may be a protocol conforming to ECHONET Lite (registered trademark), SEP (Smart Energy Profile) 2.0, KNX, or a unique dedicated protocol. Note that the first protocol and the second protocol may be different from each other, and may be, for example, both of which may be unique dedicated protocols, provided that they are protocols created according to different rules. However, the first protocol and the second protocol may be protocols created according to the same rules.

[0023] (facility) A facility according to an embodiment will be described below. As shown in Fig. 2, the facility 100 includes a solar cell device 110, a power storage device 120, a fuel cell device 130, a load device 140, and an EMS (Energy Management System) 160. The facility 100 may also include a measuring device 190.

[0024] The solar cell device 110 is a distributed power source that generates power in response to light such as sunlight. For example, the solar cell device 110 is configured with a PCS (Power Conditioning System) and a solar panel. Here, installation may mean that the solar cell device 110 and the power grid 12 are connected.

[0025] The power storage device 120 is a distributed power source that charges and discharges power. For example, the power storage device 120 is configured with a PCS and a power storage cell. Here, the term "installed" may mean that the power storage device 120 and the power grid 12 are connected to each other.

[0026] The fuel cell device 130 is a distributed power source that generates power using fuel. For example, the fuel cell device 130 is composed of a PCS and a fuel cell. Here, "installation" may mean that the fuel cell device 130 and the power system 12 are connected.

[0027] For example, the fuel cell device 130 may be a solid oxide fuel cell (SOFC; Solid Oxide Fuel Cell), a polymer electrolyte fuel cell (PEFC; Polymer Electrolyte Fuel Cell), a phosphoric acid fuel cell (PAFC; Phosphoric Acid Fuel Cell), or a molten carbonate fuel cell (MCFC; Molten Carbonate Fuel Cell).

[0028] The load device 140 is a device that consumes power. For example, the load device 140 may include an air conditioner that adjusts the temperature of a predetermined space in the facility 100, or may include a lighting device that adjusts the illuminance of a predetermined space in the facility 100. The load device 140 may include a video device, an audio device, a refrigerator, a washing machine, a personal computer, and the like.

[0029] The EMS 160 manages the power related to the facility 100. The EMS 160 may control the solar cell device 110, the power storage device 120, the fuel cell device 130, and the load devices 140. In the embodiment, the EMS 160 is illustrated as an apparatus that receives a control command from the power management server 200, but such an apparatus may be referred to as a Gateway or simply as a control unit. The EMS 160 may be referred to as a Local EMS (LEMS), a Home EMS (HEMS), or a VPP controller to distinguish it from the power management server 200. Details of the EMS 160 will be described later (see FIG. 4).

[0030] The measuring device 190 measures forward flow power from the power system 12 to the facility 100. The measuring device 190 may measure reverse flow power from the facility 100 to the power system 12. For example, the measuring device 190 may be a smart meter belonging to a power company. The measuring device 190 may transmit an information element indicating a measurement result (an integrated value of forward flow power or reverse flow power) in a first interval (e.g., 30 minutes) to the EMS 160 at the first interval. The measuring device 190 may transmit an information element indicating a measurement result in a second interval (e.g., 1 minute) shorter than the first interval to the EMS 160.

[0031] (Electricity storage device) The power storage device according to the embodiment will be described below. As shown in Fig. 3, the power storage device 120 includes a BT 121, a monitoring unit 122, and a control unit 123. Although omitted in Fig. 3, the power storage device 120 may include a PCS.

[0032] BT121 is a storage cell included in the power storage device 120.

[0033] The monitoring unit 122 monitors the frequency of the power grid 12. For example, the monitoring unit 122 is connected to a measuring device installed between the power grid 12 and the facility 100, and monitors the frequency of the power measured by the measuring device. The measuring device may be installed in a position similar to that of the measuring device 190 described above.

[0034] The control unit 123 may include at least one processor. The at least one processor may be configured by a single integrated circuit (IC), or may be configured by a plurality of circuits (such as integrated circuits and / or discrete circuits) communicatively connected to each other.

[0035] The control unit 123 controls the BT 121. In the embodiment, the control unit 123 executes specific control for autonomously controlling charging and discharging based on the frequency of the power grid 12.

[0036] (EMS) The EMS according to the embodiment will be described below. As shown in Fig. 4, the EMS 160 includes a first communication unit 161, a second communication unit 162, and a control unit 163. In the embodiment, the EMS 160 is an example of a control device that controls the power storage device 120.

[0037] The first communication unit 161 is configured by a communication module. The communication module may be a wireless communication module conforming to a standard such as IEEE802.11a / b / g / n / ac / ax, ZigBee, Wi-SUN, LTE, 5G, or 6G, or may be a wired communication module conforming to a standard such as IEEE802.3.

[0038] For example, the first communication unit 161 communicates with the power management server 200 via the network 11. As described above, the first communication unit 161 communicates according to the first protocol. For example, the first communication unit 161 receives a first message from the power management server 200 according to the first protocol. The first communication unit 161 transmits a first message response to the power management server 200 according to the first protocol.

[0039] The second communication unit 162 is configured by a communication module. The communication module may be a wireless communication module conforming to a standard such as IEEE802.11a / b / g / n / ac / ax, ZigBee, Wi-SUN, LTE, 5G, or 6G, or may be a wired communication module conforming to a standard such as IEEE802.3.

[0040] For example, the second communication unit 162 communicates with devices included in the facility 100 (the solar cell device 110, the power storage device 120, and the fuel cell device 130). As described above, the second communication unit 162 communicates according to the second protocol. For example, the second communication unit 162 transmits a second message to the distributed power source according to the second protocol. The second communication unit 162 receives a second message response from the distributed power source according to the second protocol.

[0041] The control unit 163 may include at least one processor. The at least one processor may be configured by a single integrated circuit (IC), or may be configured by a plurality of circuits (such as integrated circuits and / or discrete circuits) communicatively connected.

[0042] For example, the control unit 163 may control the distributed power sources (the solar cell device 110, the power storage device 120, and the fuel cell device 130) provided in the facility 100 based on a control command received from the power management server 200.

[0043] (Frequency fluctuation adjustment) The following describes the adjustment of the fluctuation in frequency of the power system 12 according to the embodiment.

[0044] As shown in Fig. 5, the control related to the frequency fluctuation adjustment differs for each fluctuation period to be adjusted. Specifically, the control related to the frequency fluctuation adjustment includes short-period control in which the fluctuation period to be adjusted is a short period (e.g., about several tens of seconds to several minutes), medium-period control in which the fluctuation period to be adjusted is a medium period longer than the short period (e.g., about several minutes to several tens of minutes), and long-period control in which the fluctuation period to be adjusted is a long period longer than the medium period (e.g., about several tens of minutes to several hours).

[0045] Here, the short-cycle control may be called GF (Governor Free). The short-cycle control is a control for eliminating supply and demand fluctuations that cannot be followed by the medium-cycle control. For example, such supply and demand fluctuations may cause the operation of an adjustable power source that operates under short-cycle control to stop.

[0046] The medium-term control may be called Load Frequency Control (LFC) or Automatic Frequency Control (AFC). The medium-term control is a control for eliminating supply and demand fluctuations that are difficult to predict.

[0047] The long-cycle control may be called DPC (Dispatching Power Control) or EDC (Economic Load Dispatching Control). The long-cycle control is a control for eliminating supply and demand fluctuations based on supply and demand prediction.

[0048] Although not particularly limited, the specific control in which the power storage device 120 autonomously controls charging and discharging based on the frequency of the power grid 12 may be applied to the short-period control (for example, GF) described above.

[0049] For example, when specific control is executed in short-cycle control (e.g., GF), the operation shown in Fig. 6 may be executed. Fig. 6 illustrates a case where AC and RA are separate entities. The regulated power of the power storage device 120 includes at least one of the discharge power of the power storage device 120 and the charge power of the power storage device 120. The regulated power of the power storage device 120 is power that is autonomously regulated by the power storage device 120 to keep the frequency of the power grid 12 constant.

[0050] 6, in step S10, the AC transmits to the RA a command (adjustment command) regarding adjustment of the frequency of the power grid 12. The adjustment command may be a message conforming to the above-mentioned Open ADR.

[0051] In step S11, the RA transmits to the EMS 160 a control command for the power storage device 120 for adjusting the frequency of the power grid 12. The control command may be a message between the RA and the EMS 160 in accordance with a unique protocol.

[0052] In step S20, EMS 160 sets properties related to the specific control in power storage device 120. The properties may include information elements for power storage device 120 to operate autonomously under the specific control. The properties may be considered as properties for setting the specific control in power storage device 120. Although not particularly limited, in ECHONET Lite (registered trademark), the setting of the properties may be executed by a SET command.

[0053] The power storage device 120 executes specific control to autonomously control charging and discharging based on the frequency of the power grid 12 in accordance with the property settings.

[0054] In step S21, the EMS 160 transmits a data request to the power storage device 120, requesting a combination of the frequency of the power grid 12 and the regulated power of the power storage device 120. Although not particularly limited, in ECHONET Lite (registered trademark), the data request may be executed by a GET command.

[0055] In step S22, the EMS 160 receives a data response including a combination of the frequency of the power grid 12 and the regulated power of the power storage device 120 from the power storage device 120. Although not particularly limited, in ECHONET Lite (registered trademark), the data response may be executed by a GET response command.

[0056] It should be noted that steps S21 and S22 are repeated according to the request period.

[0057] In step S30, the EMS 160 transmits performance information of the specific control to the RA. The performance information includes a combination of a frequency and an adjustment power for each request period. In the performance information, a time stamp is attached to the combination of the frequency and the adjustment power. The performance information may be a message conforming to a unique protocol between the RA and the EMS 160.

[0058] In step S31, the RA transmits a report including performance information to the AC. The report may be a message conforming to the above-mentioned Open ADR.

[0059] Here, it is assumed that the period (request period) in which the EMS 160 requests data from the power storage device 120 is longer than the period (control period) in which the power storage device 120 executes specific control. For example, the request period may be 1 s. The control period may be 100 ms or less. The control period may be considered to be the period (monitoring period) in which the power storage device 120 monitors the frequency of the power grid 12.

[0060] On the other hand, when time is adjusted using the time server 300, if a difference occurs between the communication time to the time server 300 and the communication time back from the time server 300, it is expected that an error will be 1 / 2 of this difference. For example, if the communication time on the outbound route is 0.01 seconds and the communication time on the back route is 2.01 seconds, an error of 1 second will occur. Such an error can be corrected by periodic time adjustment, etc.

[0061] However, assuming a case where time adjustment is performed using the time server 300 while the specific control is being performed, an error (e.g., 1 second) may be corrected while the specific control is being performed. That is, in the performance information from the EMS 160 to the RA, the timestamps attached to the combinations of the frequency and the regulated power may become discontinuous.

[0062] To solve this problem, the following operations are performed in the embodiment. The following options are considered as the operations.

[0063] (Option 1) Option 1 will be described below with reference to Fig. 7. In option 1, a case will be described in which the EMS 160 assigns a time stamp. That is, the EMS 160 manages the time for assigning the time stamp, and uses the time managed by the time server 300 to perform time adjustment to correct the time managed by the EMS 160.

[0064] As shown in FIG. 7, in step S41, the EMS 160 receives a control command from the RA.

[0065] In step S42, the EMS 160 uses the time server 300 to set the time.

[0066] In step S43, EMS 160 acquires a delay time and an offset by time adjustment before specific control. The delay time is a delay time (delay in FIG. 7) associated with acquiring the time managed by the time server 300. The delay time is the sum of the communication time on the way to the time server 300 and the communication time on the way back from the time server 300. The offset is the difference (offset in FIG. 7) between the time managed by the time server 300 and the time managed by EMS 160.

[0067] In step S44, the EMS 160 stops the time adjustment function using the time server 300 before the specific control.

[0068] In step S45, the power storage device 120 and the EMS 160 execute specific control. The specific control is the process of steps S20 to S22 shown in FIG.

[0069] In step S46, the EMS 160 resumes the time adjustment function using the time server 300 after the specific control.

[0070] In step S47, the EMS 160 acquires the delay time and offset by adjusting the time after the specific control.

[0071] In step S48, the EMS 160 determines whether the parameters related to time adjustment satisfy a specific condition. If the specific condition is satisfied, the EMS 160 executes the process of step S49. If the specific condition is not satisfied, the EMS 160 executes the process of step S50.

[0072] In option 1-1, the parameters may include a delay time before the specific control. The specific condition may include a condition that the delay time before the specific control is greater than a threshold. That is, in option 1-1, by determining whether the specific condition is satisfied, it is determined whether the time managed by the EMS 160 potentially includes an unacceptable error during the execution of the specific control.

[0073] Incidentally, since the offset before the specific control is used to correct the time managed by the EMS 160 before the specific control, the magnitude of the offset does not matter.

[0074] In option 1-2, the parameters may include a delay time after the specific control. The specific condition may include a condition that the delay time after the specific control is smaller than a threshold. That is, in option 1-2, by determining whether the specific condition is satisfied, it is determined whether the time managed by the EMS 160 potentially includes an unacceptable error after the specific control.

[0075] In option 1-3, the parameters may include an offset after the specific control. The specific condition may include a condition that the offset after the specific control is greater than a threshold. That is, in option 1-3, by determining whether the specific condition is satisfied, it is determined whether the time managed by EMS 160 contained an unacceptable error during the execution of the specific control.

[0076] Two or more options selected from the above-mentioned Option 1-1 to Option 1-3 may be applied.

[0077] In step S49, the EMS 160 adjusts the timestamp to be attached to the result (performance information) of the specific control, based on the offset after the specific control.

[0078] That is, according to the above-mentioned option 1-1, if it is determined that the time managed by EMS160 potentially contains an unacceptable error during execution of a specific control, the timestamp is adjusted based on the offset after the specific control.

[0079] According to option 1-2 described above, if it is determined that the time managed by EMS 160 does not potentially contain unacceptable errors after specific control, the timestamp is adjusted based on the offset after specific control.

[0080] According to the above-mentioned options 1-3, if it is determined that the time managed by EMS 160 contains an unacceptable error during execution of specific control, the timestamp is adjusted based on the offset after the specific control.

[0081] In step S50, the EMS 160 transmits the result of the specific control (performance information) with a time stamp to the RA.

[0082] (Option 2) Option 2 will be described below with reference to Fig. 8. In option 2, a case will be described in which the power storage device 120 assigns a time stamp. That is, the power storage device 120 manages the time for assigning the time stamp, and uses the time managed by the time server 300 to perform time adjustment to correct the time managed by the power storage device 120.

[0083] As shown in FIG. 8, in step S61, the EMS 160 receives a control command from the RA.

[0084] In step S62, the EMS 160 instructs the power storage device 120 to use the time server 300 to perform time adjustment.

[0085] In step S63, EMS 160 acquires the delay time and offset from power storage device 120 as a result of time adjustment performed by power storage device 120 before specific control. The delay time is the delay time (delay in FIG. 8) associated with acquiring the time managed by time server 300. The delay time is the sum of the communication time on the outbound route to time server 300 and the communication time on the return route from time server 300. The offset is the difference (offset in FIG. 8) between the time managed by time server 300 and the time managed by power storage device 120.

[0086] In step S64, the EMS 160 instructs the power storage device 120 to stop the time adjustment function using the time server 300 before the specific control.

[0087] In step S65, the power storage device 120 and the EMS 160 execute specific control. The specific control is the process of steps S20 to S22 shown in FIG.

[0088] In step S66, the EMS 160 instructs the power storage device 120 to resume the time adjustment function using the time server 300 after the specific control.

[0089] In step S67, the EMS 160 acquires the delay time and the offset from the power storage device 120 as a result of the power storage device 120 performing time adjustment after the specific control.

[0090] In step S68, the EMS 160 determines whether the parameters related to time adjustment satisfy a specific condition. If the specific condition is satisfied, the EMS 160 executes the process of step S69. If the specific condition is not satisfied, the EMS 160 executes the process of step S70.

[0091] In option 2-1, the parameters may include a delay time before the specific control. The specific condition may include a condition that the delay time before the specific control is greater than a threshold. That is, in option 2-1, by determining whether the specific condition is satisfied, it is determined whether the time managed by the power storage device 120 potentially includes an unacceptable error during the execution of the specific control.

[0092] Note that the offset before the specific control is used to correct the time managed by power storage device 120 before the specific control, so the magnitude of the offset does not matter.

[0093] In option 2-2, the parameters may include a delay time after the specific control. The specific condition may include a condition that the delay time after the specific control is smaller than a threshold. That is, in option 2-2, by determining whether the specific condition is satisfied, it is determined whether the time managed by the power storage device 120 potentially includes an unacceptable error after the specific control.

[0094] In option 2-3, the parameters may include an offset after the specific control. The specific condition may include a condition that the offset after the specific control is greater than a threshold. That is, in option 2-3, by determining whether the specific condition is satisfied, it is determined whether the time managed by the power storage device 120 contained an unacceptable error during the execution of the specific control.

[0095] Two or more options selected from the above-mentioned options 2-1 to 2-3 may be applied.

[0096] In step S69, the EMS 160 adjusts the timestamp to be attached to the result (performance information) of the specific control, based on the offset after the specific control.

[0097] That is, according to the above-mentioned option 2-1, if it is determined that the time managed by the storage device 120 potentially contains an unacceptable error during execution of the specific control, the timestamp is adjusted based on the offset after the specific control.

[0098] According to the above-mentioned option 2-2, if it is determined that the time managed by the storage device 120 does not potentially contain an unacceptable error after the specific control, the timestamp is adjusted based on the offset after the specific control.

[0099] According to the above-mentioned option 2-3, if it is determined that the time managed by the storage device 120 contains an unacceptable error during execution of the specific control, the timestamp is adjusted based on the offset after the specific control.

[0100] In step S70, the EMS 160 transmits the result of the specific control (performance information) with a time stamp to the RA.

[0101] (Action and Effects) In the embodiment, in the case where a time stamp is added based on the time managed by the EMS 160, the EMS 160 stops the time adjustment function before the specific control and resumes the time adjustment function after the specific control (Option 1 described above). With this configuration, by using the time managed by the EMS 160 (local time) during the execution of the specific control, discontinuity in the time stamp can be prevented.

[0102] In the embodiment, in a case where a time stamp is added based on the time managed by the power storage device 120, the EMS 160 instructs the power storage device 120 to stop the time adjustment function before the specific control, and instructs the power storage device 120 to resume the time adjustment function after the specific control (Option 2 described above). With this configuration, by using the time managed by the power storage device 120 (local time) during the execution of the specific control, discontinuity in the time stamp can be prevented.

[0103] Under such a premise, when the parameters related to time adjustment satisfy the specific condition, the EMS 160 adjusts the timestamp based on the offset after the specific control. With such a configuration, when the error of the local time, such as the time managed by the EMS 160 or the time managed by the power storage device 120, is assumed to be large during the execution of the specific control, the timestamp can be appropriately adjusted. In other words, when the error of the local time is assumed to be small during the execution of the specific control, unnecessary adjustment of the timestamp can be omitted (the above-mentioned options 1-1, 1-3, 2-1, 2-3, etc.). Furthermore, when the local time is assumed to not include a potential error after the specific control, the timestamp can be appropriately adjusted. In other words, when the local time is assumed to include a potential error after the specific control, unnecessary adjustment of the timestamp can be omitted (the above-mentioned options 1-2, 2-2, etc.).

[0104] [Other embodiments] Although the present invention has been described by the above-mentioned embodiment, the description and drawings forming a part of this disclosure should not be understood as limiting the present invention. From this disclosure, various alternative embodiments, examples and operating techniques will become apparent to those skilled in the art.

[0105] Although not specifically mentioned in the above disclosure, a case may be assumed in which ECHONET Lite (registered trademark) is used as the protocol between the power storage device 120 and the EMS 160. In such a case, a command by which the EMS 160 instructs the power storage device 120 to perform time adjustment may be defined as a new SET command. A command by which the EMS 160 instructs the power storage device 120 to stop the time adjustment function may be defined as a new SET command. A command by which the EMS 160 instructs the power storage device 120 to resume the time adjustment function may be defined as a new SET command. A command by which the EMS 160 requests an offset from the power storage device 120 may be defined as a new GET command. A command by which the EMS 160 requests a delay time from the power storage device 120 may be defined as a new GET command.

[0106] Although not specifically mentioned in the above disclosure, stopping the time setting function may be interpreted as disabling or deactivating the time setting function, and resuming the time setting function may be interpreted as enabling or activating the time setting function.

[0107] In the above disclosure, a case has been exemplified in which the data response transmitted from the power storage device 120 to the EMS 160 includes the frequency of the power grid 12 itself. However, the above disclosure is not limited to this. The data response transmitted from the power storage device 120 to the EMS 160 may include frequency information related to the frequency of the power grid 12. For example, the frequency information may include a deviation of the frequency of the power grid 12 rather than the frequency of the power grid 12 itself. In such a case, in the above disclosure, "frequency" may be read as "frequency deviation."

[0108] Although not specifically mentioned in the above disclosure, the specific control may be executed in units of a predetermined time interval (e.g., 3 hours). If the time adjustment function is stopped during execution of the specific control, the error that may occur in the predetermined time interval may be assumed to be about 10 to 100 ms.

[0109] In the above disclosure, a case where the specific control is applied to short-period control (e.g., GF) has been exemplified. However, the above disclosure is not limited to this. The specific control may be applied to control related to frequency fluctuation adjustment. That is, the specific control may be applied to medium-period control (e.g., LFC or AFC) or long-period control (e.g., DPC or EDC).

[0110] In the above disclosure, ECHONET Lite has been mainly described. However, the above disclosure is not limited thereto. The above disclosure can also be applied to other protocols such as SEP2.0 and KNX.

[0111] Although not specifically mentioned in the above disclosure, at least a part of the functions of the EMS 160 may be executed by a server located on the network 11. In other words, the EMS 160 may be provided by a cloud service. [Explanation of symbols]

[0112] Reference Signs List 1...Power management system, 11...Network, 12...Power system, 100...Facility, 110...Solar cell device, 120...Power storage device, 121...BT, 122...Monitoring unit, 123...Control unit, 130...Fuel cell device, 140...Load device, 160...EMS, 161...First communication unit, 162...Second communication unit, 163...Control unit, 190...Measuring device, 200...Power management server, 300...Time server

Claims

1. a power storage device that executes specific control for controlling charging and discharging based on a frequency of a power grid; A control device that controls the power storage device, The control device includes: before the specific control, stopping a time adjustment function for adjusting a time managed by the control device using a time managed by a time server; restarting the time setting function after the specific control; The power system adjusts a timestamp attached to a result of the specific control when a parameter related to the time adjustment satisfies a specific condition.

2. The power system according to claim 1 , wherein the specific condition includes a condition that a delay time associated with acquisition of the time managed by the time server before the specific control is greater than a threshold value.

3. The power system according to claim 1 or 2, wherein the specific condition includes a condition that a delay time associated with acquisition of the time managed by the time server after the specific control is smaller than a threshold value.

4. a power storage device that executes specific control for controlling charging and discharging based on a frequency of a power grid; A control device that controls the power storage device, The control device includes: before the specific control, setting, in the power storage device, a stop of a time adjustment function relating to time adjustment that corrects a time managed by the control device using a time managed by a time server; After the specific control, a restart of the time setting function is set in the power storage device; The power storage device is The power system adjusts a timestamp attached to a result of the specific control when a parameter related to the time adjustment satisfies a specific condition.

5. The power system according to claim 4 , wherein the specific condition includes a condition that a delay time associated with acquisition of the time managed by the time server before the specific control is greater than a threshold value.

6. The power system according to claim 4 or 5, wherein the specific condition includes a condition that a delay time associated with acquisition of the time managed by the time server after the specific control is smaller than a threshold value.

7. a control device that controls a power storage device that executes specific control for controlling charging and discharging based on a frequency of a power grid, stopping a time adjustment function related to time adjustment that corrects a time managed by the control device using a time managed by a time server, before the specific control; the control device restarting the time setting function after the specific control; The control method includes a step of adjusting a timestamp attached to a result of the specific control by the control device when a parameter related to the time adjustment satisfies a specific condition.

8. a control device that controls a power storage device that executes specific control for controlling charging and discharging based on a frequency of a power grid, before the specific control, sets a time adjustment function for adjusting a time managed by the control device using a time managed by a time server to be stopped in the power storage device; a step of the control device setting the power storage device to resume the time adjustment function after the specific control; The control method includes a step of adjusting a timestamp attached to a result of the specific control by the power storage device when the parameter related to the time adjustment satisfies a specific condition.

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