Power measuring equipment and distribution boards

Abstract

To provide an electric power measurement device that can detect a removal of an electric current measurement member from an electric power line in which the electric current measurement member is installed, and to prove a power distribution board that includes the electric current measurement member.SOLUTION: An electric power measurement device 10 is the device that measures an amount of electric power to be supplied from an electric current line of a measurement object. The electric power measurement device 10 comprises: an electric current measurement member 2; an electric current measurement unit 11; and a state detection unit 12. The electric current measurement member 2 has a through-hole passing the electric power line, and is configured to be switchable between a closed state where the through-hole is partitioned from the outside and an open state where the through-hole and the outside are continuous. The electric current measurement unit 11 is electrically connected to the electric current measurement member 2, and is configured to measure an electric current flowing through the electric power line when the electric current measurement member 2 is in the closed state. The state detection unit 12 is configured to monitor a state of the electric current measurement member 2 to detect occurrence of the open state.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a power measurement device and a distribution board, and more particularly to a power measurement device that measures the amount of power supplied from a power line, and a distribution board including the same. [Background technology]

[0002] Patent Document 1 discloses a residential distribution board (distribution board). The distribution board includes a box body in which multiple switches are housed and in which the operation parts of the switches are exposed on the front, and a door body whose one edge is pivotally attached to the box body so as to open and close between a position that covers the front of the box body and a position that opens it. The distribution board also includes a measurement unit that measures the power flowing into the distribution board from the main line. The measurement unit is connected to current transformers (CTs) attached to the L1 and L2 phases of the system power supply, which is the main line, and measures the amount of power received from the main line. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-65374 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, a current measuring member such as a current transformer that measures the current of a power line passing through a through hole is electrically insulated from the power line and can be easily moved or removed. In particular, a current measuring member that is configured to be able to switch the through hole to a state where it is continuous with the outside of the current measuring member can be moved or removed without stopping the power line or inserting or removing it from the terminal of the distribution board. Therefore, the higher the possibility that the current measuring member is moved from the power line to be measured, the lower the reliability that the measured power is the current of the power line to be measured.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a power measuring device that can detect when a current measuring member is removed from a power line on which the current measuring member is installed, and a distribution board equipped with the same. [Means for solving the problem]

[0006] A power measurement device according to one aspect of the present disclosure is a power measurement device that measures the amount of power supplied from a power line to be measured. The power measurement device includes a current measurement member, a current measurement unit, and a state detection unit. The current measurement member has a through hole through which the power line passes, and is configured to be switchable between a closed state in which the through hole is separated from the outside, and an open state in which the through hole is continuous with the outside. The current measurement unit is electrically connected to the current measurement member, and measures the current flowing through the power line when the current measurement member is in the closed state. The state detection unit monitors the state of the current measurement member to detect the occurrence of an open state. When the state detection unit detects the occurrence of the open state, the state detection unit does not cancel the detection of the occurrence of the open state even if the state detection unit detects the closed state.

[0007] A distribution board according to an aspect of the present disclosure includes the power measuring device and a cabinet for the distribution board. The power line to be measured is a main line. Effect of the Invention

[0008] According to an aspect of the present disclosure, a power measuring device and a distribution board can detect when a current measuring member is removed from a power line on which the current measuring member is installed. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a functional block diagram of the power measuring device according to the first embodiment. [Diagram 2] FIG. 2 is a schematic diagram of the current measuring member according to the first embodiment. [Diagram 3] FIG. 3 is an explanatory diagram of the distribution board according to the first embodiment as viewed from the front. [Figure 4] FIG. 4 is a conceptual diagram showing a schematic configuration of the distribution board of the above embodiment. [Diagram 5] FIG. 5 is a state transition diagram showing the operation of the power measuring device according to the embodiment. [Figure 6] FIG. 6 is a functional block diagram of the power measuring device according to the second embodiment. [Figure 7] FIG. 7 is a schematic diagram of a current measuring member according to another modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] [Embodiment 1] Hereinafter, a power measuring device 10 and a current measuring member 2 according to an embodiment of the present disclosure will be described with reference to the drawings.

[0011] 1. Configuration 1.1 Overview of power measurement equipment FIG. 1 is a functional block diagram of a power measurement device 10 according to the first embodiment. The power measurement device 10 includes a device body 1 and a current measurement member 2. The device body 1 includes a current measurement section 11, a state detection section 12, a storage section 13, an alarm section 14, a communication section 15, an operation section 16, a control section 17, and a power supply section 18. The current measurement member 2 is a so-called current transformer (CT). As shown in FIG. 2, the current measurement member 2 has a through hole 21 for passing a power line to be measured, and includes a core 22 surrounding the through hole 21. FIG. 2 is a schematic diagram of the current measurement member 2 according to the first embodiment. Details will be described later.

[0012] 1 and 2, the current measuring unit 11 is a circuit that is connected to the current measuring member 2 and measures the current flowing through the power line that passes through the through hole 21 of the current measuring member 2. The current measuring unit 11 measures the current value at predetermined time intervals.

[0013] The state detection unit 12 is a circuit connected to the current measurement member 2 and detects whether the current measurement member 2 is in a closed state or an open state. Here, the closed state of the current measurement member 2 refers to a state in which the core 22 of the current measurement member 2 forms a closed loop around the through hole 21 as viewed from the axial direction of the core 22. In other words, the closed state of the current measurement member 2 refers to a state in which the core 22 separates the through hole 21 from the outside of the core 22 as viewed from the axial direction of the core 22. On the other hand, the open state of the current measurement member 2 refers to a state in which the core 22 of the current measurement member 2 does not form a closed loop as viewed from the axial direction of the core 22. In other words, the open state of the current measurement member 2 refers to a state in which the core 22 has an open portion and the through hole 21 is connected to the outside of the core 22 as viewed from the axial direction of the core 22. When the control unit 17 instructs the start of monitoring, the state detection unit 12 monitors whether the current measurement member 2 is in a closed state or an open state. Furthermore, when the state detection unit 12 detects that the current measurement member 2 is in the open state, it causes the state detection unit 12 to store information indicating that the open state has occurred in the state storage unit 131 of the storage unit 13. Note that the state detection unit 12 may include the time at which the open state has occurred in the information indicating that the open state has occurred.

[0014] The storage unit 13 is a storage medium that holds information related to monitoring the state of the state detection unit 12. The storage unit 13 includes a state holding unit 131 that holds whether or not the open state of the current measuring member 2 has been detected. The storage unit 13 is preferably a non-volatile storage medium so that information is not lost in the event of a power outage.

[0015] The alarm unit 14 is a circuit for notifying a user when the state detection unit 12 detects that the current measurement member 2 is in an open state. The alarm unit 14 has, for example, an LED, and notifies the user of the open state of the current measurement member 2 by light from the LED. Alternatively, for example, the alarm unit 14 has a speaker, and notifies the user of the open state of the current measurement member 2 by an alarm sound or a voice message. Note that, if the alarm unit 14 has a display unit, the alarm unit 14 may cause the display unit to display a warning.

[0016] The communication unit 15 is an interface for transmitting power information measured by the current measurement unit 11 and information indicating the open state of the current measurement member 2 detected by the state detection unit 12 to the external device 3. The communication unit 15 may also receive an instruction from the external device 3 regarding monitoring of the current measurement member 2 by the state detection unit 12. The external device 3 is, for example, a controller of a Home Energy Management System (HEMS). The communication method between the power measurement device 10 and the controller is, for example, wireless communication using radio waves as a medium that complies with a communication standard such as a specific low-power radio station (a radio station that does not require a license) in the 920 MHz band, Wi-Fi (registered trademark), or Bluetooth (registered trademark). Alternatively, the communication method between the power measurement device 10 and the controller may be wired communication such as Ethernet. The external device 3 is not limited to a HEMS controller, and may be, for example, a server of a building management company or a server of a power company.

[0017] The operation unit 16 is an interface for receiving instructions from a contractor or the like, such as to start or stop the operation of the power measuring device 10. The operation unit 16 is, for example, a button or a switch provided on the surface of the device main body 1. The operation unit 16 may be, for example, a keyboard having an interface that is detachable from the device main body 1.

[0018] The control unit 17 is a circuit that controls starting and stopping of power measurement and state monitoring of the current measuring member 2, and receiving instructions and transmitting data from the external device 3. The control unit 17 is, for example, a combination of a processor such as a CPU (Central Processing Unit), a memory, and software. Note that the control unit 17 may also be a combination of an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit), and a memory.

[0019] Power supply unit 18 is connected to each of the secondary terminals of main breaker 4, and supplies power to each functional block of power measurement device 10. Power supply unit 18 converts the power received from main breaker 4 into direct current for supply to each functional block of power measurement device 10, and supplies power to each functional block of power measurement device 10.

[0020] 1.2 Details of current measuring component 2 As shown in FIG. 2, the current measurement member 2 includes a first portion 23 and a second portion 24. The first portion 23 has a first recess 211 facing the through hole 21, a first surface 271, and a second surface 272. One end (first end) of the first recess 211 is continuous with the first surface 271. The other end (second end) of the first recess 211 is continuous with the second surface 272. The second portion 24 has a second recess 221 facing the through hole 21, a third surface 281, and a fourth surface 282. One end (third end) of the second recess 221 is continuous with the third surface 281. The other end (fourth end) of the second recess 221 is continuous with the fourth surface 282. When the current measurement member 2 is in the closed state, one end of the first recess 211 and one end of the second recess 221 are in contact with each other. Moreover, the first surface 271 and the third surface 281 face each other and are in contact with each other. Furthermore, when the current measurement member 2 is in the closed state, the other end of the first recess 211 and the other end of the second recess 221 face each other and are in contact with each other. Furthermore, the second surface 272 and the fourth surface 282 face each other and are in contact with each other. When the current measurement member 2 is in the closed state, the first recess 211 and the second recess 221 form the outer circumferential surface of the through hole 21.

[0021] One end of the first surface 271 is continuous with the first recess 211. A first engagement portion 231 is provided at the other end of the first surface 271. One end of the third surface 281 is continuous with the second recess 221. A second engagement portion 241 is provided at the other end of the third surface 281. When the current measurement member 2 is in the closed state, the first engagement portion 231 and the second engagement portion 241 are engaged with each other. When the engagement between the first engagement portion 231 and the second engagement portion 241 is released, the current measurement member 2 can be set to the open state.

[0022] One end of the second surface 272 is continuous with the first recess 211. One end of the fourth surface 282 is continuous with the second recess 221. The other end of the second surface 272 and the other end of the fourth surface 282 are continuous with each other via the joint 232. The joint 232 allows the relative position of the first portion 23 and the second portion 24 to be changed while maintaining the other end of the second surface 272 and the other end of the fourth surface 282 in contact with each other. That is, the second portion 24 is configured to be rotatable relative to the first portion 23 with the joint 232 as the rotation axis. The state in which the first surface 271 and the third surface 281 are in contact with each other and the second surface 272 and the fourth surface 282 are in contact with each other is the closed state as described above. On the other hand, the state in which the first surface 271 and the third surface 281 are separated from each other and the second surface 272 and the fourth surface 282 are separated from each other is the open state. In the open state, the current measurement member 2 is in a state in which the through hole 21 is connected to the outside of the current measurement member 2 via the space between the first surface 271 and the third surface 281. That is, the current measurement member 2 in the open state can be moved relative to the power line so that the power line passes through the space between the first surface 271 and the third surface 281. Therefore, with the current measurement member 2 in the open state, it is easy to insert the power line into the through hole 21 or remove the power line from the through hole 21 without moving the power line or removing it from the contact terminal.

[0023] The current measurement member 2 includes an open / close sensor 27. The open / close sensor 27 is provided in the first portion 23 near the joint 232. The open / close sensor 27 is a sensor that detects whether the current measurement member 2 is in an open state or a closed state. The open / close sensor 27 is, for example, a microswitch, and a pressure detection portion protrudes from the second surface 272. When the current measurement member 2 is in a closed state, the pressure detection portion is pressed by the fourth surface 282, and the open / close sensor 27 detects the closed state. When the current measurement member 2 is in an open state, the pressure detection portion is not pressed by the fourth surface 282, and the open / close sensor 27 detects the open state.

[0024] The first portion 23 includes a first core portion 25 constituting the core 22. The second portion 24 includes a second core portion 26 constituting the core 22. One end (first end) of the first core portion 25 is exposed from a first surface 271. The other end (second end) of the first core portion 25 is exposed from a second surface 272. One end (third end) of the second core portion 26 is exposed from a third surface 281. The other end (fourth end) of the second core portion 26 is exposed from a fourth surface 282. When the current measurement member 2 is in a closed state, the first surface 271 and the third surface 281 are in contact with each other, and one end of the first core portion 25 and one end of the second core portion 26 are in contact with each other. When the current measurement member 2 is in a closed state, the second surface 272 and the fourth surface 282 are in contact with each other, and the other end of the first core portion 25 and the other end of the second core portion 26 are in contact with each other. Therefore, when the current measurement member 2 is in the closed state, the first core part 25 and the second core part 26 are magnetically coupled to form the core 22, which is a single loop-type core. A current detection coil connected to the current measurement unit 11 is wound around the first core part 25. Therefore, when the current measurement member 2 is in the closed state, the current measurement unit 11 can measure the magnitude of the current flowing through the power line passing through the through hole 21.

[0025] 1.3 Overview of distribution boards The overall configuration of a distribution board 30 including a power measuring device 10 according to the first embodiment will be described.

[0026] Fig. 3 is an explanatory diagram of a distribution board 30 according to the first embodiment as viewed from the front. Fig. 4 is a conceptual diagram showing a schematic configuration of the distribution board 30 according to the first embodiment. The distribution board 30 includes a device main body 1, a main breaker 4, a plurality of switches 5, and a distribution board cabinet 31. The distribution board cabinet 31 houses the device main body 1, the main breaker 4, and the plurality of switches 5.

[0027] The main breaker 4 has a plurality of primary terminals 41 (three in the illustrated example) and a plurality of secondary terminals. The main breaker 4 has contacts for each of the plurality of primary terminals 41 that are connected to an electric circuit between the primary terminal 41 and the secondary terminal. The main breaker 4 has an operating lever 43 on its front side for turning the contacts on and off. The main breaker 4 also has a main breaker section that cuts off the contacts when it detects an abnormal state in which an overcurrent, such as a leakage current or an overload current, flows through the contacts.

[0028] In the distribution board 30 of the first embodiment, a single-phase three-wire system is assumed as the power distribution system, and therefore a single-phase three-wire system service line 200 of a system power supply (commercial power supply) is electrically connected to a primary terminal 41 of the main breaker 4. A conductive bar of a first voltage pole (L1 phase), a conductive bar of a second voltage pole (L2 phase), and a conductive bar of a neutral pole (N phase) are connected to a secondary terminal of the main breaker 4. Each conductive bar is formed into an elongated plate shape that is long in the left-right direction by a conductive member, and constitutes the main line 6.

[0029] The switches 5 are arranged in a row in the left-right direction, separated into the upper side and the lower side of the conductive bar of the neutral pole (N phase). Here, as shown in FIG. 4, each switch 5 is inserted between one of the branch circuits 8 and the trunk line 6. That is, the branch circuit 8 is connected to the trunk line 6 via the corresponding switch 5. The "branch circuit" in the present disclosure is each of the circuits electrically connected to the trunk line 6 and branched into a plurality of circuits from the trunk line 6 at the distribution board 30. In the present embodiment, the branch circuit 8 includes an electric wire 81 and a load 82. The electric wire 81 is electrically connected to the secondary side terminal of the switch 5. The load 82 includes, for example, lighting equipment, air conditioners, television receivers, hot water supply equipment, and wiring equipment such as a socket (outlet) or a wall switch. The load 82 is electrically connected to the switch 5 via the electric wire 81.

[0030] The device main body 1 has a current measuring function for measuring at least one of the power and the current supplied from the service line 200, and a communication function for communicating with devices arranged outside the distribution board 30.

[0031] The current measurement members 2 are attached to the L1 phase and the L2 phase of the drop line 200. The power measurement device 10 measures the currents of the L1 phase and the L2 phase of the drop line 200 and calculates the power value. The power measurement device 10 also monitors whether each of the current measurement members 2 attached to the drop line 200 maintains a closed state and detects an open state. Note that a current measurement member 2 may also be attached to the N phase of the drop line 200.

[0032] 2. Operation The following describes the operation of the power measuring device 10 according to the embodiment 1. FIG.

[0033] When the construction is completed and the operation lever 43 of the main breaker 4 is turned on, the power measuring device 10 transitions to a standby state st1. The power measuring device 10 in the standby state st1 is in a state in which it can communicate with the external device 3. The power measuring device 10 in the standby state st1 does not measure the power supplied from the service line 200, nor monitors whether each of the current measuring members 2 maintains a closed state. The power measuring device 10 in the standby state also receives, from the operation unit 16 or the external device 3, an instruction for initial settings such as time setting, settings related to communication between the power measuring device 10 and the external device 3, and addition or deletion of the external device 3 (step S11). For example, the construction company inputs parameters for communicating with the HEMS controller from the operation unit 16, so that the power measuring device 10 in the standby state st1 can communicate with the HEMS controller as the external device 3. Or, for example, when a contractor performs a pairing operation of Bluetooth (registered trademark), the power measuring device 10 in the standby state st1 becomes capable of communicating with a smartphone or a tablet terminal on which a control app of the power measuring device 10 is running, as the external device 3. Or, for example, when a contractor inputs a URL of a power company server from the operation unit 16 or the external device 3, the power measuring device 10 in the standby state st1 becomes capable of communicating with the power company server, as the external device 3.

[0034] Furthermore, the power measuring device 10 in the standby state st1 receives an instruction to transition to the monitoring state st2 from the external device 3 (step S12). For example, when the external device 3 is a power company server, the power measuring device 10 performs the following process in step S12. First, the power measuring device 10 receives an operation by the construction company on the operation unit 16, and adds the tablet terminal on which the control app of the power measuring device 10 is running as the external device 3. Next, the power measuring device 10 receives an operation by the construction company to the control app of the tablet terminal on the communication unit 15, and adds the power company server as the external device 3. Then, the construction company takes an image using the tablet terminal to confirm that the current measurement member 2 is correctly attached to the drop line 200, and registers the image in the power company server. The power company operator checks the image, and when it verifies that the construction company has correctly installed the current measurement member 2, registers that fact in the power company server. The power company server, which is the external device 3, transmits an instruction to transition to the monitoring state st2 to the power measuring device 10 for which verification of the current measurement member 2 has been completed. When the communication unit 15 of the power measuring device 10 receives an instruction to transition to the monitoring state from the power company server, which is the external device 3, the power measuring device 10 transitions to the monitoring state st2. When the communication unit 15 of the power measuring device 10 in the standby state st1 receives an instruction to monitor a power value from the external device 3, the power measuring device 10 may transmit the power value from the communication unit 15 to the external device 3. For example, an operator of the power company may cause the power company server to transmit an instruction to monitor a power value to the power measuring device 10, and determine whether the installation state is correct from the power value received from the power measuring device 10. When an image is registered, the power company server may verify the installation state of the current measuring member 2 by image recognition without the intervention of an operator, and transmit an instruction to transition to the monitoring state st2 if the verification is successful.

[0035] The power measuring device 10 in the monitoring state st2 measures the amount of power supplied from the service line 200 using the current measurement members 2. The power measuring device 10 in the monitoring state st2 transfers the measured amount of power to a HEMS controller or a power company server. The power measuring device 10 in the monitoring state st2 may transfer the measured amount of power periodically or whenever there is a change. The power measuring device 10 in the monitoring state st2 may also transfer the measured amount of power in association with the time of measurement. The power measuring device 10 in the monitoring state st2 also monitors whether each of the current measurement members 2 is maintained in a closed state (step S21). When the power measuring device 10 in the monitoring state st2 detects that at least one of the current measurement members 2 is in an open state, it transitions to an error detection state st3 (step S22). Furthermore, when the power measurement device 10 in the monitoring state st2 is instructed by the external device 3 to transition to the standby state st1, the power measurement device 10 authenticates whether the instruction is a legitimate instruction, and transitions to the standby state st1 if the authentication is successful (step S23). A method for authenticating whether the instruction from the external device 3 is a legitimate instruction is, for example, password authentication. Alternatively, a method for authenticating whether the instruction from the external device 3 is a legitimate instruction may be a confirmation of whether the external device 3 has authority to issue an instruction to transition to the standby state. For example, when registering the external device 3 in the standby state power measurement device 10, the external device 3 is authenticated by a password or the like, and if the authentication is successful, the external device 3 is given authority to issue an instruction to transition to the standby state. Then, when the communication unit 15 receives an instruction to transition to the standby state from the external device 3 that has authority to issue an instruction to transition to the standby state, the power measurement device 10 in the monitoring state st2 transitions to the standby state st1. According to this method, for example, by not granting the tablet terminal of the installer of the power measuring device 10 the authority to instruct the transition to a standby state, it is possible to prevent the monitoring of the current measuring member 2 from being stopped without the permission of the power company.

[0036] In step S22, the power measurement device 10 that has transitioned to the error detection state st3 holds information indicating the error detection state in the state holding unit 131. The information indicating the error detection state is information indicating that there is a history of the current measurement member 2 being in an open state. Then, the power measurement device 10 in the error detection state issues a warning indicating that the current measurement member 2 is in an open state by the alarm unit 14 (step S31). The warning indicating that the current measurement member 2 is in an open state may be, for example, a voice or alarm sound output from the speaker of the alarm unit 14, a lighting or blinking LED, or a display on a display. Alternatively, the alarm unit 14 may notify the external device 3 that the current measurement member 2 is in an open state, and the external device 3 may issue a warning. For example, when the external device 3 is a HEMS controller, the HEMS controller may cause a smart meter connected to the HEMS controller to issue a warning indicating that the current measurement member 2 is in an open state. Alternatively, for example, when the external device 3 is a power company server, the power company server may notify an inspector of the power company together with the installation location of the power measurement device 10. Also, for example, the power company server may associate the amount of power received from the power measuring device 10 after receiving the notification with information indicating that the amount of power may be incorrect. Furthermore, the power measuring device 10 in the error detection state st3 transfers the measured amount of power to the HEMS controller or the power company server. Note that the power measuring device 10 in the error detection state st3 may continue to monitor whether each of the current measurement members 2 is maintained in the closed state. However, even if the power measuring device 10 in the error detection state st3 detects that all of the current measurement members 2 are in the closed state, the power measuring device 10 in the error detection state st3 maintains the error detection state st3 and does not transition to the monitoring state st2. Furthermore, when the power measuring device 10 in the error detection state st3 is instructed by the external device 3 to transition to the standby state st1, it authenticates whether the instruction is legitimate, and transitions to the standby state st1 if the authentication is successful (step S32). Furthermore, when the power measurement device 10 in the error detection state st3 is instructed by the external device 3 to reset the error state, the power measurement device 10 authenticates whether the instruction is legitimate, and if the authentication is successful, transitions to the monitoring state st2 (step S33).When the power measuring device 10 transitions from the error detection state st3 to the standby state st1 or the monitoring state st2, the power measuring device 10 clears the information held in the state holding unit 131 indicating that the power measuring device 10 is in the error detection state.

[0037] 3. Summary According to the power measuring device 10 of the first embodiment, it is possible to detect that the current measuring member 2 attached to the drop line 200, which is the power line to be measured, has become open. Therefore, when a user, a construction worker, or the like mistakenly removes or attempts to remove the current measuring member 2, the manager of the power measuring device 10 can quickly deal with the situation. In addition, when the current measuring member 2 becomes open, the error detection state st3 of the power measuring device 10 is not released until a regular reset instruction or a regular standby instruction is received. Therefore, the error detection state st3 can be released only when it is confirmed that the current measuring member 2 is correctly attached to the drop line 200. In other words, when the power measuring device 10 is in the monitoring state st2, it is possible to trust that the amount of power measured by the power measuring device 10 is the amount of power of the drop line 200. Therefore, the reliability of the amount of power measured by the power measuring device 10 can be evaluated depending on whether the power measuring device 10 is in the monitoring state st2 or the error detection state st3. Therefore, when a user or a third party intentionally attaches the current measuring member 2 to another power line, it is possible to detect that the amount of power measured by the power measuring device 10 may be incorrect. Therefore, it is possible to prevent billing errors and erroneous control of grid interconnection based on an erroneous amount of power that is contrary to the intention of the administrator of the power measuring device 10 or the administrator of the power equipment connected to the power line being measured.

[0038] [Variation 1] In the first embodiment, the power measuring device 10 needs a transition instruction from the external device 3 when switching from the standby state st1 to the monitoring state st2. However, for example, when the administrator of the external device 3 that receives the amount of power measured by the power measuring device 10 can trust the construction company, the procedure may be simplified.

[0039] 1. Operation In the power measuring device 10 according to the first modification, when it is detected in step S12 that communication with the external device 3 that is to receive the amount of power has been established, the power measuring device 10 transitions to a monitoring state st2. For example, if the external device 3 is a power company server, the power measuring device 10 communicates with the power company server from the communication unit 15 based on information about the power company server input by the installer. The power measuring device 10 transmits, for example, a customer number for an electricity receiving contract to the power company server from the communication unit 15. If there is no defect in the information transmitted by the communication unit 15 of the power measuring device 10, the power company server does not reject the connection but responds indicating that communication is permitted. When the power measuring device 10 receives a response indicating that communication is permitted from the power company server, which is the external device 3, the power measuring device 10 transitions to a monitoring state st2.

[0040] 2. Summary The power measuring device 10 according to the first modification can also detect that the current measuring member 2 attached to the drop wire 200, which is the power line to be measured, has entered an open state. Moreover, the power measuring device 10 according to the first modification transitions to the monitoring state st2 when communication with the external device 3 is established. Therefore, if the administrator of the external device 3 that receives the amount of power measured by the power measuring device 10 can trust the contractor that installed the power measuring device 10, it is possible to omit checking the installation state of the power measuring device 10. This reduces the burden on the administrator of the external device 3.

[0041] [Variation 2] In the first embodiment and the first modification, the power measuring device 10 needs to communicate with the external device 3 when switching from the standby state st1 to the monitoring state st2. However, for example, when the manager of the external device 3 that receives the amount of power measured by the power measuring device 10 can trust the construction company, the procedure may be simplified.

[0042] 1. Operation In the power measuring device 10 according to the second modification, in step S12, when a contractor or the like operates the operation unit 16 to instruct a transition to the monitoring state st2, the power measuring device 10 transitions to the monitoring state st2. For example, when the contractor presses a monitoring start button on the operation unit 16, the power measuring device 10 transitions to the monitoring state st2.

[0043] The operation unit 16 may be configured so that only specific persons can operate the instruction to transition to the monitoring state st2. For example, a locked cover may be attached to the monitoring start button of the operation unit 16 so that only a person who has the key can operate it. Alternatively, for example, a key lock switch may be used as the monitoring start switch of the operation unit 16. Alternatively, for example, the monitoring state st2 may be transitioned to when a password is input after the monitoring start button is pressed. Alternatively, the monitoring state st2 may be transitioned to when a special input is input, such as pressing two specific buttons simultaneously or pressing buttons in a specific order.

[0044] 2. Summary The power measuring device 10 according to the second modification can also detect that the current measuring member 2 attached to the drop line 200, which is the power line to be measured, has entered the open state. Moreover, the power measuring device 10 according to the second modification transitions the power measuring device 10 to the monitoring state st2 at the location where the power measuring device 10 is installed. Therefore, the administrator of the external device 3 does not need to be involved in transitioning the power measuring device 10 to the monitoring state st2, thereby saving labor. Moreover, by configuring the operation unit 16 so that only specific persons can operate the instruction to transition to the monitoring state st2, it is possible to transition to the monitoring state st2 only when the installation of the current measuring member 2 is reliable.

[0045] [Variation 3] In the first embodiment and the first and second modifications, when switching the power measuring device 10 from the standby state st1 to the monitoring state st2, an instruction to transition to the monitoring state st2 is required. However, for example, when the administrator of the external device 3 that receives the amount of power measured by the power measuring device 10 can trust the contractor, the procedure may be simplified.

[0046] 1. Operation In the power measuring device 10 according to the third modification, when an installer or the like starts the operation of the power measuring device 10 in step S12, the power measuring device 10 immediately transitions to a monitoring state st2 rather than to a standby state st1.

[0047] Furthermore, when a construction worker or the like starts the operation of the power measuring device 10, the power measuring device 10 may automatically transition to the monitoring state st2 after a predetermined time has elapsed. The predetermined time may be, for example, one hour, eight hours, or one day. The predetermined time is preferably, for example, the time required for the construction of the distribution board 30 to be completed after the operation of the power measuring device 10 is started.

[0048] 2. Summary The power measuring device 10 according to the third modification can also detect that the current measuring member 2 attached to the service line 200, which is the power line to be measured, has become open. Moreover, the power measuring device 10 according to the third modification transitions to the monitoring state st2 immediately or after a predetermined time has elapsed since the power measuring device 10 starts operating. Therefore, the administrator of the external device 3 does not need to be involved in the transition of the power measuring device 10 to the monitoring state st2, which can save labor. Furthermore, by configuring the power measuring device 10 to transition to the monitoring state st2 after a predetermined time has elapsed since the power measuring device 10 starts operating, even if an open state occurs during installation of the current measuring member 2, it can be excluded from the detection target. In other words, it is possible to detect the open state of the current measuring member 2 during operation of the power measuring device 10 without erroneously detecting the open state of the current measuring member 2 during installation of the power measuring device 10.

[0049] [Variation 4] In the first embodiment and modifications 1-3, when switching the power measuring device 10 from the error detection state st3 to the monitoring state st2, a transition instruction is required from the external device 3. However, for example, when the administrator of the external device 3 that receives the amount of power measured by the power measuring device 10 can trust the construction company, the procedure may be simplified.

[0050] 1.Operation In the power measuring device 10 according to the fourth modification, in step S33, when a construction worker who has visited the site operates the operation unit 16 to instruct a transition to the monitoring state st2, the device transitions to the standby state st1 or the monitoring state st2. The operation unit 16 is configured so that only a specific person can operate it. For example, a locked cover may be attached to the error reset button of the operation unit 16 so that only a person who has the key can operate it. Alternatively, for example, a key lock switch may be used as the error reset switch of the operation unit 16. Alternatively, for example, when a password is input after the error reset button is pressed, the device may transition to the monitoring state st2. Alternatively, for example, when a special input is input, such as pressing two specific buttons simultaneously or pressing buttons in a specific order, the device may transition to the monitoring state st2.

[0051] Similarly, when switching the power measuring device 10 from the monitoring state st2 or the error detection state st3 to the standby state st1, an input from the operation unit 16 may be accepted. In this case, the operation unit 16 is similarly configured so that only specific persons can operate it. Note that, if a key is required to operate the operation unit 16, the same key may be used to switch from the error detection state st3 to the monitoring state st2 and to switch the power measuring device 10 from the monitoring state st2 or the error detection state st3 to the standby state st1.

[0052] 2. Summary The power measuring device 10 according to the fourth modification can also detect that the current measuring member 2 attached to the service line 200, which is the power line to be measured, has entered an open state. Moreover, the power measuring device 10 according to the fourth modification can cancel the error detection state st3 of the power measuring device 10 and transition to the standby state st1 at the place where the power measuring device 10 is installed. Therefore, there is no need for the administrator of the external device 3 to be involved, and labor can be saved. Furthermore, by configuring the operation unit 16 so that only specific persons can operate the cancellation of the error detection state st3 and the transition to the standby state st1, it is not possible to cancel the error or monitoring unless it is confirmed on-site that the current measuring member 2 is correctly attached. Therefore, it is possible to prevent a user or a third party from controlling the monitoring state of the power measuring device 10 in an attempt to avoid detection of the removal or movement of the current measuring member 2.

[0053] [Embodiment 2] 1. Configuration 6 is a functional block diagram of a power measuring device 10A according to the second embodiment. The same components as those in the first embodiment are given the same reference numerals and will not be described. The power measuring device 10A includes a device main body 1A and a current measuring member 2. The device main body 1A includes a current measuring section 11, a state detecting section 12, a memory section 13A, an alarm section 14, a communication section 15, an operation section 16, a control section 17, a voltage measuring section 181, and a power supply section 18A. The power supply section 18A of the device main body 1A is electrically connected to a standby power source 19.

[0054] The storage unit 13A is a storage medium that stores information related to monitoring the state of the state detection unit 12. The storage unit 13A includes a state storage unit 131 and a power outage information storage unit 132. The state storage unit 131 stores whether or not the open state of the current measurement member 2 has been detected. The power outage information storage unit 132 stores a state in which the voltage of the drop line 200 becomes zero, that is, the time when the power outage state occurred and the time when it was resolved.

[0055] Voltage measurement unit 181 is connected to each of the secondary terminals of main breaker 4 and measures the voltage. Since a single-phase three-wire system is also assumed as the power distribution system in the second embodiment, voltage measurement unit 181 measures the voltage between L1 phase and N phase, the voltage between L2 phase and N phase, and the voltage between L1 phase and L2 phase. Voltage measurement unit 181 outputs the measured voltages to control unit 17.

[0056] Like the power supply unit 18, the power supply unit 18A is connected to each of the secondary terminals of the main breaker 4 and supplies power to each functional block of the power measuring device 10A. The power supply unit 18A converts the power received from the main breaker 4 into DC for supplying to each functional block of the power measuring device 10A, and supplies power to each functional block of the power measuring device 10A. In addition to the function of the power supply unit 18, the power supply unit 18A has a function of supplying DC from the standby power source 19 to each functional block of the power measuring device 10A when the voltage of the secondary terminal of the main breaker 4 becomes 0. When the output voltage of the standby power source 19 differs from the voltage required by each functional block of the power measuring device 10A, the power supply unit 18A converts the voltage by stepping up or stepping down to supply the required voltage to each functional block of the power measuring device 10A. The power supply unit 18A also has a function of supplying DC to the standby power source 19 and controlling charging.

[0057] The standby power supply 19 is electrically connected to the power supply unit 18A, and functions as a power supply for the power measurement device 10A while the power supply from the secondary terminal of the main breaker 4 to the power measurement device 10A is stopped. The standby power supply 19 is, for example, a secondary battery such as a lithium ion battery or a nickel-metal hydride battery. The standby power supply 19 may be a primary battery such as a lithium battery or an alkaline battery. When the standby power supply 19 is a primary battery, the power supply unit 18A does not have the function of supplying direct current to the standby power supply 19 and controlling charging. When the standby power supply 19 is a primary battery, it is preferable that the power supply unit 18A has a function of managing the remaining amount of the standby power supply 19. It is also preferable that the standby power supply 19 is replaceable by the administrator of the power measurement device 10A or a contractor designated by the administrator. On the other hand, it is preferable that the standby power supply 19 is locked or fixed with a special screw so that the user or a third party cannot easily remove the standby power supply 19.

[0058] 2. Operation The following describes the operation of power measuring device 10A according to embodiment 2. Note that the same operations as those in embodiment 1 are denoted by the same reference numerals, and the description thereof will be omitted.

[0059] When the installation is completed and the operation lever 43 of the main breaker 4 is turned on, the power measuring device 10A transitions to a standby state st1 (see FIG. 5). The power measuring device 10A in the standby state st1 operates in the same manner as the power measuring device 10 in the standby state st1. Note that while the voltage detected by the voltage measuring unit 181 is 0, the power measuring device 10A in the standby state st1 may not operate until the voltage detected by the voltage measuring unit 181 recovers.

[0060] When the voltage measured by the voltage measuring unit 181 is normal, the power measuring device 10A in the monitoring state st2 (see FIG. 5) performs the same operation as the power measuring device 10. That is, the power measuring device 10A measures the power supplied from the service line 200 using the current measuring member 2. The power measuring device 10A in the monitoring state st2 transfers the measured amount of power to the HEMS controller or the power company server. The power measuring device 10A in the monitoring state st2 may transfer the measured amount of power periodically or whenever there is a change. The power measuring device 10A in the monitoring state st2 may transfer the measured amount of power in association with the time of measurement. The power measuring device 10 in the monitoring state st2 monitors whether each of the current measuring members 2 is maintained in the closed state. When the power measuring device 10 in the monitoring state st2 detects that at least one of the current measuring members 2 is in the open state, the power measuring device 10 transitions to the error detection state st3. Furthermore, when the power measuring device 10A in the monitoring state st2 is instructed by the external device 3 to transition to the standby state st1, the power measuring device 10A authenticates whether the instruction is legitimate, and transitions to the standby state st1 if the authentication is successful.

[0061] Furthermore, when the voltage measured by the voltage measuring unit 181 becomes 0, that is, when a power outage of the main line 6 is detected, the power measuring device 10A in the monitoring state st2 performs the following operation. The power supply unit 18A switches the power source so that the power measuring device 10A operates with the power of the standby power source 19. Then, the power measuring device 10A stores information that the voltage has become 0 together with the time of occurrence in the power outage information storage unit 132. Furthermore, the power measuring device 10A continues to monitor whether each of the current measurement members 2 is maintained in the closed state. When the power measuring device 10 in the monitoring state st2 detects that at least one of the current measurement members 2 is in the open state, the power measuring device 10 stores information indicating an error detection state in the state storage unit 131, and transitions to the error detection state st3. Note that the power measuring device 10A in the monitoring state st2 may temporarily stop measuring the power supplied from the service line 200. Furthermore, the power measuring device 10A in the monitoring state st2 may temporarily stop the function of the communication unit 15. When the voltage measured by the voltage measuring unit 181 of the power measuring device 10A in the monitoring state st2 is restored, the power measuring device 10A stores the voltage value together with the restoration time in the power failure information storage unit 132. Then, the power supply unit 18A switches the power source so that the power measuring device 10A operates with the power of the main line 6. Furthermore, if the function of the communication unit 15 has been temporarily stopped, the power measuring device 10A resumes the function of the communication unit 15. Furthermore, the power measuring device 10A transmits to the external device 3 the time when the voltage became 0 and the time when the voltage was restored. Furthermore, if there is any power data that has not been transmitted to the external device 3, the power measuring device 10A transmits it to the external device 3. Then, the power measuring device 10A restores to the operation when the voltage detected by the voltage measuring unit 181 is normal.

[0062] When the power measuring device 10A transitions to the error detection state st3 (see FIG. 5) if the voltage measured by the voltage measuring unit 181 is normal, the power measuring device 10A performs the same operation as the power measuring device 10. That is, the power measuring device 10 in the error detection state issues a warning from the alarm unit 14 indicating that the current measurement member 2 has entered an open state. The power measuring device 10 in the error detection state st3 also transfers the measured amount of power to the HEMS controller or the power company server. When the power measuring device 10 in the error detection state st3 is instructed by the external device 3 to transition to the standby state st1, the power measuring device 10 authenticates whether the instruction is legitimate, and transitions to the standby state st1 if the authentication is successful. When the power measuring device 10 in the error detection state st3 is instructed by the external device 3 to reset the error state, the power measuring device 10 authenticates whether the instruction is legitimate, and transitions to the monitoring state st2 if the authentication is successful. When the power measuring device 10 transitions from the error detection state st3 to the standby state st1 or the monitoring state st2, the power measuring device 10 clears the information held in the state holding unit 131 indicating that the power measuring device 10 is in the error detection state.

[0063] When the power measuring device 10A in the error detection state st3 detects a power outage of the main line 6, it performs the following operation. The power supply unit 18A switches the power source so that the power measuring device 10A operates with the power of the standby power source 19. Then, the power measuring device 10A stores information that the voltage has become 0 in the power outage information storage unit 132 together with the time of occurrence. Furthermore, the power measuring device 10A issues a warning from the alarm unit 14 indicating that the current measurement member 2 has entered an open state. Note that the alarm unit 14 may wait to output a warning until the voltage detected by the voltage measuring unit 181 is restored. Furthermore, the power measuring device 10A stores the measured amount of power, and waits to transfer the amount of power until the voltage detected by the voltage measuring unit 181 is restored. When the voltage measured by the voltage measuring unit 181 is restored, the power measuring device 10A stores the voltage value together with the recovery time in the power outage information storage unit 132. Then, when the power measuring device 10A has been waiting to output a warning, it outputs a warning. Furthermore, the power measuring device 10A transmits the time when the voltage became 0 and the time when the voltage recovered to the external device 3. Furthermore, if there is any power data that has not been transmitted to the external device 3, the power measuring device 10A transmits it to the external device 3. Then, the power measuring device 10A recovers to the operation when the voltage detected by the voltage measuring unit 181 is normal.

[0064] Moreover, when the power measuring device 10A transitions from the monitoring state st2 to the error detection state st3 while the main line 6 remains in a power outage state, the following operation is performed. The power measuring device 10A issues a warning indicating that the current measurement member 2 has entered an open state through the alarm unit 14. The alarm unit 14 may wait to output a warning until the voltage detected by the voltage measuring unit 181 is restored. The power measuring device 10A holds the measured amount of power and waits to transfer the amount of power until the voltage detected by the voltage measuring unit 181 is restored. When the voltage measured by the voltage measuring unit 181 is restored, the power measuring device 10A holds the voltage value together with the recovery time in the power outage information holding unit 132. Then, when the output of a warning was on hold, the power measuring device 10A outputs a warning. The power measuring device 10A transmits the time when the voltage became 0 and the time when the voltage was restored to the external device 3. If there is any power data that has not been transmitted to the external device 3, the power measuring device 10A transmits it to the external device 3. Then, power measuring device 10A recovers to the operation that would occur if the voltage detected by voltage measuring unit 181 was normal.

[0065] 3. Summary According to the power measuring device 10A of the second embodiment, it is possible to detect that the current measuring member 2 attached to the service line 200, which is the power line to be measured, has been opened. Therefore, when a user, a construction worker, or the like mistakenly removes or attempts to remove the current measuring member 2, a manager, or the like, can quickly take action. Furthermore, even if the service line 200 experiences a power outage, the power measuring device 10A does not stop monitoring the current measuring member 2. Therefore, even during a power outage or when the user or a third party intentionally turns off the main breaker 4, it is possible to monitor whether the current measuring member 2 has been moved.

[0066] [Variation 1] In each of the above-described embodiments and modifications, when the power measuring device 10 or the power measuring device 10A detects that the current measuring member 2 is open, the power measuring device 10 or the power measuring device 10A immediately notifies the user or the external device 3. However, for example, the power measuring device 10 or the power measuring device 10A may only monitor the current measuring member 2 and not notify the user.

[0067] 1. Operation When the power measuring device 10A according to the first modification detects the open state of the current measurement member 2 in the monitoring state st2, the power measuring device 10A stores a record of the change of the current measurement member 2 to the open state in the state storage unit 131 in association with the time of occurrence. Then, the power measuring device 10A continues the monitoring state st2. The power measuring device 10A does not issue an alarm from the alarm unit 14. The power measuring device 10A transmits information of the change of the current measurement member 2 to the open state and the time of occurrence to the external device 3 from the communication unit 15. Furthermore, the power measuring device 10A continuously and repeatedly performs an operation of transmitting the amount of power measured by the current measuring unit 11 to the external device 3. Note that when the power measuring device 10A detects the closed state of the current measurement member 2, it may transmit a record of the change of the current measurement member 2 to the closed state. Furthermore, when the power measuring device 10A detects that the current measuring member 2 has changed to the open state, the power measuring device 10A associates the change to the open state of the current measuring member 2 with the time of occurrence and stores the record in the state storage unit 131. Then, the power measuring device 10A transmits information that the current measuring member 2 has changed to the open state and the time of occurrence to the external device 3 from the communication unit 15.

[0068] The external device 3 may determine whether the current measurement member 2 has been removed from the drop line 200 based on the record of the current measurement member 2 changing to the open state, the record of the current measurement member 2 changing to the closed state, and the power value received from the power measurement device 10A. For example, if the time when the current measurement member 2 changed to the open state is registered in advance as the installation date and time or the maintenance work date and time, the external device 3 determines that the detection is not an error. Also, for example, if the time when the current measurement member 2 changed to the open state is not the installation date and time or the maintenance work date and time, the external device 3 determines that the detection may be an error. Based on the determination of the external device 3, the administrator of the power measurement device 10A checks the site to confirm whether the installation state of the current measurement member 2 is correct. Also, for example, if the time when the current measurement member 2 was in the open state is sufficiently shorter than the time required for the current measurement member 2 removal operation, the external device 3 determines that the user or a third party simply opened the current measurement member 2. Based on the determination of the external device 3, the administrator of the power measuring device 10A notifies the user of the result.

[0069] When the external device 3 determines that the current measurement member 2 has been removed from the drop line 200 based on the record that the current measurement member 2 has changed to the open state or the record that the current measurement member 2 has changed to the closed state, and the power value, the external device 3 may transmit an error notification to the power measuring device 10A. When the power measuring device 10A receives the error notification from the external device 3, the power measuring device 10A may transition to an error detection state st3 and cause the alarm unit 14 to issue an alarm.

[0070] 2. Summary According to the power measuring device 10A of the first modification, it is possible to detect that the current measuring member 2 attached to the drop line 200, which is the power line to be measured, has been put into an open state. Therefore, when a user, a construction worker, or the like mistakenly removes or attempts to remove the current measuring member 2, a manager or the like can quickly deal with the situation. Furthermore, when the power measuring device 10A of the first modification detects that the current measuring member 2 is in an open state, the power measuring device 10A notifies the external device 3 and does not issue an alarm. Therefore, the manager of the power measuring device 10A can comprehensively determine whether the current measuring member 2 has been moved or not based on the time when the current measuring member 2 changed to the open state, the time when the current measuring member 2 changed to the closed state, and the power value received by the external device 3. That is, it is possible to monitor whether the current measuring member 2 has been moved or not without excessively issuing an alarm.

[0071] [Other variations] (1) The method by which the state detection unit 12 detects whether the current measurement member 2 is in the open state or the closed state is not limited to the above-mentioned method. For example, the open / close sensor 27 of the current measurement member 2 only needs to be provided in a position where it can detect whether the current measurement member 2 is in the open state or the closed state, and does not have to be in the vicinity of the joint 232. Furthermore, for example, the open / close sensor 27 of the current measurement member 2 is not limited to a microswitch and may be a non-contact sensor.

[0072] The method of the state detection unit 12 detecting whether the current measurement member 2 is in the open state or the closed state may be as follows. For example, an open / close detection coil may be provided in the first core portion 25 of the current measurement member 2, and the open / close detection coil and the state detection unit 12 may be electrically connected. The state detection unit 12 can detect whether the current measurement member 2 is in the open state or the closed state, for example, by passing a current through the open / close detection coil and comparing it with the current detected by the current measurement unit 11. Alternatively, for example, the state detection unit 12 may apply a voltage to the open / close detection coil and measure the impedance or inductance to detect whether the current measurement member 2 is in the open state or the closed state. Alternatively, for example, the current measurement member 2 may not be provided with an open / close detection coil, and the state detection unit 12 may measure the impedance or inductance of the current detection coil to detect whether the current measurement member 2 is in the open state or the closed state.

[0073] The state detection unit 12 may also estimate that a period during which the current or power measured by the current measurement unit 11 is zero is a period during which the current measurement member 2 is in an open state. If the current amount of the power line that is the object of measurement by the current measurement member 2 is unlikely to be zero, the current amount being zero is considered to be a high possibility that the current measurement member 2 is not functioning normally. The state detection unit 12 may also estimate that the current measurement member 2 is in an open state if the state during which the current or power measured by the current measurement unit 11 is zero continues for a predetermined time or more. Alternatively, for example, the state detection unit 12 may also estimate that a period during which the voltage measured by the voltage measurement unit 181 is zero is a period during which the current measurement member 2 is in an open state. The state detection unit 12 may also estimate that the current measurement member 2 is in an open state if the state during which the voltage measured by the voltage measurement unit 181 is zero continues for a predetermined time or more.

[0074] (2) The current measuring member 2A may be provided with a locking mechanism 235 so that the current measuring member 2A cannot be easily changed from a closed state to an open state.

[0075] 7 is a schematic diagram of a current measurement member 2A including a locking mechanism 235. The current measurement member 2A includes a first portion 23A, a second portion 24A, and a locking member 234. The first portion 23A has a first protrusion 233. The second portion 24A has a second protrusion 243. The locking mechanism 235 includes the locking member 234, the first protrusion 233, and the second protrusion 243.

[0076] The first projection 233 protrudes in the thickness direction of the first portion 23A, and an end portion thereof is in contact with the first surface 271. The first projection 233 has a through hole in a direction perpendicular to the first surface 271. The second projection 243 protrudes in the thickness direction of the second portion 24A, and an end portion thereof is in contact with the third surface 281. The second projection 243 has a through hole in a direction perpendicular to the third surface 281. When the current measuring member 2 is in the closed state, the through hole of the first projection 233 and the through hole of the second projection 243 are aligned on the same straight line. The locking member 234 is provided so as to penetrate both the through hole of the first projection 233 and the through hole of the second projection 243. The locking member 234 is, for example, a cable tie. Alternatively, for example, the locking member 234 may be a lock, or may be a combination of a bolt and a nut that cannot be removed without a dedicated tool.

[0077] The lock mechanism 235 may be any mechanism that limits the people who can change the current measurement member 2 from the closed state to the open state, and the position and structure are not limited to the above example. Alternatively, the lock mechanism 235 may be a mechanism that prevents an operator from changing the state to the open state by mistake. For example, the current measurement member 2 may be configured such that it requires both hands to change the state from the closed state to the open state, or the operation method is difficult to understand without referring to a procedure manual, etc. By adopting such a configuration, it is possible to prevent an accident in which an operator mistakenly opens the current measurement member 2 for another current transformer. Alternatively, the lock mechanism 235 may be a mechanism that allows an operator to easily check whether or not the current measurement member 2 has been changed to the open state. For example, the lock mechanism 235 may be a cable tie wrapped around the current measurement member 2, or a paper sticker affixed across the first part 23 and the second part 24. When the current measurement member 2 is opened, the lock mechanism 235 is irreversibly destroyed and cannot be restored to its original state, which serves as a deterrent against tampering, etc.

[0078] (3) The power line on which the power measuring device 10 measures power using the current measuring member 2 is not limited to a grid power supply. For example, the power measuring device 10 may use the current measuring member 2 to measure power supplied from a power conditioner. The source of power supply to the power conditioner may be any of a solar cell, a fuel cell, an electric vehicle, and a storage battery system, or a combination of these. Alternatively, for example, the power measuring device 10 may use the current measuring member 2 to measure power supplied from a gas power generation system. In addition, the external device 3 that receives data on power measured by the power measuring device 10 is not limited to a power company server, and may be, for example, a HEMS server or a server of a maintenance company for power generation equipment.

[0079] In addition, the external device 3 to which the power measuring device 10 sends power data and the external device 3 that receives notification that the current measuring member 2 is in an open state and sends an instruction to clear the error detection state of the power measuring device 10 do not have to be the same device.

[0080] Furthermore, the power measurement device 10 may measure the power supplied from a solar cell, a fuel cell, an electric vehicle, or a storage battery system, using the current measurement member 2. The current measurement member 2 may include a Hall element inserted between a part of the first core portion 25 and the remaining part of the first core portion 25, instead of the current detection coil wound around the first core portion 25.

[0081] (4) The above-described embodiments and modifications are merely a part of the various embodiments and modifications of the present invention. In addition, the embodiments and modifications can be modified in various ways depending on the design, etc., as long as the object of the present invention can be achieved. In addition, one embodiment and another embodiment, one embodiment and another modification, or one modification and another modification may be combined as appropriate.

[0082] [summary] A power measuring device (10; 10A) according to a first aspect is a device that measures the amount of power supplied from a power line (200) to be measured. The power measuring device (10; 10A) includes a current measuring member (2; 2A), a current measuring unit (11), and a state detecting unit (12). The current measuring member (2; 2A) has a through hole (21) through which the power line (200) passes, and is configured to be switchable between a closed state in which the through hole (21) is separated from the outside, and an open state in which the through hole (21) is continuous with the outside. The current measuring unit (11) is electrically connected to the current measuring member (2; 2A) and measures the current flowing through the power line (200) when the current measuring member (2; 2A) is in the closed state. The state detecting unit (12) monitors the state of the current measuring member (2; 2A) to detect the occurrence of an open state.

[0083] According to the power measuring device (10; 10A) of the first aspect, it is possible to detect that the current measuring member (2; 2A) has been removed or is about to be removed from the power line (200) to be measured. Therefore, when the current measuring member (2; 2A) is removed from the power line (200) to be measured, it is possible to take action promptly. In addition, since it is possible to recognize that the reliability of the power value measured by the power measuring device (10; 10A) has decreased, it is possible to prevent processing based on an erroneous power value.

[0084] In the power measuring device (10; 10A) according to the second aspect, in the first aspect, the device further includes an alarm unit (14). The alarm unit (14) issues an alarm when the state detection unit (12) detects the occurrence of an open state.

[0085] According to the power measuring device (10; 10A) of the second aspect, it is possible to notify and warn a person who is attempting to inappropriately remove the current measuring member (2; 2A) that the act has been detected. Alternatively, according to the power measuring device (10; 10A) of the second aspect, it is possible to quickly notify the administrator of the power measuring device (10; 10A) that an attempt has been made to inappropriately remove the current measuring member (2; 2A).

[0086] In the power measuring device (10; 10A) according to the third aspect, in the first or second aspect, the status detection unit (12) starts monitoring the status of the current measurement member (2; 2A) after a predetermined time has elapsed since the current measuring unit (11) started operating.

[0087] According to the power measuring device (10; 10A) of the third aspect, for example, it is possible to prevent the attachment of the current measuring member (2; 2A) during the installation work of the power measuring device (10; 10A) from being erroneously detected as an inappropriate removal of the current measuring member (2; 2A). Furthermore, according to the power measuring device (10; 10A) of the third aspect, after the installation work of the power measuring device (10; 10A) is completed, it is possible to start monitoring the removal of the current measuring member (2; 2A) without performing any special operation.

[0088] A power measuring device (10; 10A) according to a fourth aspect is any one of the first to third aspects, further comprising an operation unit (16). The operation unit (16) accepts an operation by a user. The state detection unit (12) starts monitoring the state of the current measuring member (2; 2A) when a predetermined operation is performed on the operation unit (16).

[0089] According to the power measuring device (10; 10A) of the fourth aspect, for example, it is possible to prevent the attachment of the current measuring member (2; 2A) during the installation work of the power measuring device (10; 10A) from being erroneously detected as an inappropriate removal of the current measuring member (2; 2A). Furthermore, according to the power measuring device (10; 10A) of the fourth aspect, after the installation work of the power measuring device (10; 10A) is completed, it is possible to immediately start monitoring whether the current measuring member (2; 2A) is not removed by a predetermined operation.

[0090] In a power measuring device (10; 10A) according to a fifth aspect, the predetermined operation is a first predetermined operation in the fourth aspect. When a second predetermined operation is performed on the operation unit (16) while the state detection unit (12) detects the occurrence of the open state, the state detection unit (12) cancels the detection of the occurrence of the open state.

[0091] According to the power measuring device (10; 10A) of the fifth aspect, the detection state can be cancelled when an installer or manager of the power measuring device (10; 10A) confirms that the current measurement member (2; 2A) is installed on the power line (200) to be measured. Therefore, it is possible to confirm from the detection state that the current measurement member (2; 2A) is correctly attached to the power line to be measured.

[0092] A power measuring device (10; 10A) according to a sixth aspect is any one of the first to fifth aspects, and further includes a communication unit (15). The communication unit (15) communicates with the external device (3). When the state detection unit (12) detects the occurrence of the open state, the communication unit (15) transmits information indicating the occurrence of the open state to the external device (3).

[0093] According to the power measuring device (10; 10A) of the sixth aspect, it is possible to confirm from an external device (3) that the current measuring member (2; 2A) has been removed or is about to be removed from the power line (200) to be measured. Therefore, even if the installer or manager of the power measuring device (10; 10A) cannot directly monitor the power measuring device (10; 10A), it is possible to monitor whether the current measuring member (2; 2A) is correctly attached to the power line (200) to be measured.

[0094] In the power measuring device (10; 10A) of the seventh aspect, in the sixth aspect, when the communication unit (15) receives at least one of an instruction to start monitoring the state of the current measuring member (2; 2A) and an instruction to cancel the notification of the occurrence of an open state from the external device (3), the state detection unit (12) starts monitoring the state of the current measuring member (2; 2A) or cancels the notification of the occurrence of the open state in accordance with the instruction.

[0095] According to the power measuring device (10; 10A) of the seventh aspect, the monitoring state of whether or not the current measuring member (2; 2A) is correctly attached to the power line (200) to be measured can be controlled from the external device (3). Therefore, for example, when a construction company is requested to install the power measuring device (10; 10A) or check the installation state of the current measuring member (2; 2A), the manager can remotely start monitoring the current measuring member (2; 2A) or cancel the detection state. In other words, when a construction company is requested to do so, it is not necessary to transfer the authority to start monitoring the current measuring member (2; 2A) or cancel the detection state.

[0096] A power measuring device (10; 10A) according to an eighth aspect is any one of the first to seventh aspects, and further includes a status holding unit (131) and a transmission unit (communication unit 15). The status holding unit (131) holds a change in the status of the current measuring member (2; 2A) obtained by the status detection unit (12) through monitoring in association with the date and time of the occurrence of the change in status. The transmission unit (communication unit 15) transmits the information held by the status holding unit (131) to the outside.

[0097] According to the power measuring device (10; 10A) of the eighth aspect, a manager at a remote location can check the state and changes of the current measuring member (2; 2A). Therefore, the normality and the reliability of the measurement results of the power measuring device can be evaluated according to the situation, for example, state changes that are not contrary to the manager's intentions, such as state changes due to installation work or maintenance work, can be regarded as normal, and state changes while the resident is at home can be regarded as inappropriate work by the resident.

[0098] A power measurement device (10A) according to a ninth aspect is any one of the first to eighth aspects, and further includes a voltage measurement unit (181), a power supply unit (18A), and a power failure information storage unit (132). The voltage measurement unit (181) measures the voltage of the power line (200). The power supply unit (18A) is connected to a standby power source (19) and causes the standby power source (19) to supply power to the power measurement device (10A) when power supply to the power line (200) is stopped. The power failure information storage unit (132) stores a period during which power supply to the power line (200) is stopped.

[0099] The power measuring device (10A) according to the ninth aspect can detect a power outage in the power line (200) to be measured. Furthermore, the power measuring device (10A) according to the ninth aspect may be able to detect when the current measuring member (2; 2A) is removed during a power outage.

[0100] In a power measuring device (10; 10A) according to a tenth aspect, in any one of the first to ninth aspects, the current measuring member (2A) includes a locking mechanism (235). The locking mechanism (235) prevents switching from a closed state to an open state.

[0101] According to the power measuring device (10; 10A) of the tenth aspect, it is not easy to remove the current measuring member (2A) from the power line (200) to be measured. Therefore, it is possible to more effectively prevent accidents in which the current measuring member (2A) is inappropriately removed from the power line (200) to be observed.

[0102] A distribution board (30) according to an eleventh aspect includes a power measuring device (10; 10A) according to any one of the first to tenth aspects and a distribution board cabinet (31). The power line to be measured is a main line (6).

[0103] According to the distribution board (30) of the eleventh aspect, it is possible to measure the power of the trunk line (6) upstream of the distribution board (30). In addition, since the current value of the trunk line (6) is measured by the current measuring member (2; 2A), it is easy to add a power measuring device (10; 10A) after the installation of the distribution board (30). [Explanation of symbols]

[0104] 10,10A Power Metering Device 11 Current measurement section 12 Status detection unit 131 State Holder 132 Power outage information holding unit 14 Alarm section 15 Communication unit (transmission unit) 16 Control section 181 Voltage measurement section 19 Standby power supply 2,2A current measuring device 21 Through hole 30 Distribution Board 31 Distribution cabinet 3 External device 6 main line 200 Power line

Claims

1. A power measurement device for measuring an amount of power supplied from a power line to be measured, a current measuring member having a through hole through which the power line passes and configured to be switchable between a closed state in which the through hole is separated from the outside and an open state in which the through hole is continuous with the outside; a current measuring unit electrically connected to the current measuring member and configured to measure a current flowing through the power line when the current measuring member is in the closed state; a state detection unit that monitors a state of the current measuring member to detect the occurrence of the open state; Equipped with when the state detection unit detects the occurrence of the open state, the state detection unit does not cancel the detection of the occurrence of the open state even if the state detection unit detects the closed state. Power measuring equipment.

2. The locking mechanism further includes an alarm unit that issues an alarm when the state detection unit detects the occurrence of the open state. The power measurement device according to claim 1 .

3. The state detection unit starts monitoring the state of the current measurement member after a predetermined time has elapsed since the current measurement unit started operating. The power measuring device according to claim 1 or 2.

4. Further comprising an operation unit for receiving an operation from a user, The state detection unit starts monitoring the state of the current measuring member when a predetermined operation is performed on the operation unit. The power measuring device according to claim 1 .

5. The predetermined operation is a first predetermined operation, When a second predetermined operation is performed on the operation unit while the state detection unit is detecting the occurrence of the open state, the state detection unit cancels the detection of the occurrence of the open state. The power measurement device according to claim 4 .

6. Further comprising a communication unit for communicating with an external device; The communication unit transmits information indicating the occurrence of the open state to the external device when the state detection unit detects the occurrence of the open state. The power measuring device according to claim 1 .

7. when the communication unit receives at least one of an instruction to start monitoring the state of the current measuring member and an instruction to stop detecting the occurrence of the open state from the external device, The state detection unit starts monitoring the state of the current measuring member or cancels detection of the occurrence of the open state in accordance with the instruction. The power measurement device according to claim 6.

8. a status storage unit that stores a change in the state of the current measuring member obtained by the status detection unit through monitoring in association with a date and time when the change in state occurred; a transmission unit that transmits the information held by the status holding unit to an external device; Further comprising: The power measuring device according to claim 1 .

9. A voltage measurement unit that measures a voltage of the power line; a power supply unit connected to a standby power supply and supplying power from the standby power supply to the power measuring device when power supply to the power line is stopped; A power outage information storage unit that stores a power outage period of the power line; Further comprising The power measuring device according to claim 1 .

10. The current measuring member includes a lock mechanism that prevents the current measuring member from being switched from the closed state to the open state. The power measuring device according to claim 1 .

11. The power measuring device according to any one of claims 1 to 10, A distribution board cabinet is provided. The power line to be measured is a main line. Distribution board.

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