Power circuit breaker and power interruption system equipped therewith, method for protecting a power circuit breaker, protection program

Abstract

To enable improvement in the protection function of a power breaker including a relay without separately using a temperature sensor for temperature detection, etc., and to provide a power interruption system including such a power breaker, a protection method for the power breaker and a protection program.SOLUTION: A power breaker 20 comprises a power relay 21, a temperature calculation section 22a and a determination section 22b. The power relay 21 includes a drive coil 21a. The temperature calculation section 22a calculates a temperature of the drive coil 21a by calculating a resistance value of resistance which is changed with a temperature change in a case where the drive coil 21a included in the power relay 21 is regarded as resistance. Based on the temperature of the drive coil 21a calculated in the temperature calculation section 22a, the determination section 22b determines whether to interrupt power supply.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a power circuit breaker including a relay, a power interruption system equipped therewith, a method for protecting a power circuit breaker, and a protection program. [Background technology]

[0002] In recent years, devices and systems have been used that monitor the temperature rise of electrical appliances such as relays and determine whether or not to stop their operation depending on whether or not an abnormality has occurred. For example, Patent Document 1 discloses a method for providing a predetermined location monitoring method that ensures user privacy, which is performed by an electrical plug connection device and a management server, and includes the steps of: (A) the management server deriving behavioral characteristics of an electrical appliance and constructing a behavioral characteristic identification model; (B) the electrical plug connection device generating event data of an electrical appliance and transmitting the event data to the management server; (C) the management server determining whether the event data matches multiple behavioral characteristics using the behavioral characteristic identification model; and (D) the management server sending a warning message to a user terminal device associated with the user if it determines that there is no match for any of the characteristics. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-68855 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] However, the conventional method of monitoring a designated location described above has the following problems. In other words, the predetermined location monitoring method disclosed in the above-mentioned publication includes a temperature measurement module for measuring the temperature of an electrical appliance, and determines whether or not an event (abnormality) has occurred in the electrical appliance based on the temperature measurement result and the current measurement result.

[0005] In this configuration, when detecting an abnormal rise in ambient temperature of electrical appliances such as relays and stopping their operation, it is necessary to set a tolerable range that is somewhat on the safe side when deciding whether to stop operation. Furthermore, after stopping the operation of an electrical appliance due to an abnormal rise in ambient temperature, it is difficult to remotely determine whether the abnormal temperature rise has been resolved and whether it is possible to resume operation, so it is necessary to perform the work directly on-site.

[0006] The object of the present invention is to provide a power interruption system, a power interruption method, and a protection program that can improve the protection function of a power interruption device including a relay without using a separate temperature sensor or the like for temperature detection. [Means for solving the problem]

[0007] The power circuit breaker according to the first invention is a power circuit breaker that monitors the temperature of a relay that interrupts the power supply to an electrical device and determines whether or not to interrupt the power supply, and comprises a relay, a temperature calculation unit, and a determination unit. The relay includes a drive coil. The temperature calculation unit calculates the temperature of the drive coil by calculating the resistance value of the resistance that changes with temperature, assuming that the drive coil included in the relay is a resistor. The determination unit determines whether or not to interrupt the power supply based on the temperature of the drive coil calculated by the temperature calculation unit.

[0008] In this power circuit breaker, which includes a relay that cuts off the power supply to electrical equipment as needed, the drive coil included in the relay is considered as a resistor. By utilizing the fact that the resistance value of the drive coil changes with temperature changes, the temperature of the drive coil is calculated based on that resistance value, and a decision is made as to whether or not to cut off the power supply. Accordingly, by detecting that the relay has entered an abnormally high temperature state by calculating the resistance value of the drive coil included in the relay, it is possible to easily determine whether to cut off the power supply. As a result, the protection function of the power circuit breaker including the relay can be improved without separately using a temperature sensor or the like for temperature detection.

[0009] A power circuit breaker according to a second invention is the power circuit breaker according to the first invention, wherein the determination unit determines that an abnormality has occurred and cuts off the power supply when a temperature rise exceeding a first threshold value occurs within a predetermined time.

[0010] Here, the predetermined time is, for example, about 1 to 3 seconds, and the first threshold value is set to, for example, 20°C / sec, or a reached temperature of 100°C. Accordingly, when a temperature rise exceeding the first threshold value is detected within a predetermined time, it is determined that an abnormality caused by a rapid temperature rise has occurred, and safety can be ensured by cutting off the power supply.

[0011] A power circuit breaker according to a third invention is the power circuit breaker according to the first or second invention, wherein the determination unit determines that the state is normal and does not cut off the power supply when no temperature rise exceeding the first threshold value occurs within a predetermined time. Accordingly, for example, even when there is a gentle temperature rise within a predetermined time, since the temperature rise is not rapid, it can be determined as a normal state and it can be determined not to cut off the power supply.

[0012] A power circuit breaker according to a fourth invention is the power circuit breaker according to the first or second invention, wherein the determination unit determines that an abnormality has occurred and cuts off the power supply when a temperature rise exceeding a second threshold value occurs. Here, the predetermined time is, for example, about 5 seconds, and the second threshold value is set to, for example, 100°C. This allows for improved safety by detecting a potential anomaly when the temperature rise reaches a second threshold, and then shutting off the power supply.

[0013] The power circuit breaker according to the fifth invention is the power circuit breaker according to the fourth invention, further comprising an operation recovery determination unit that, after the determination unit has determined that there is a temperature rise exceeding a second threshold and the power supply should be interrupted, restores the operation of the relay when the temperature falls below a third threshold for determining operation recovery.

[0014] Here, the third threshold is set to restore the operation of a relay that has had its power supply cut off, and is set to, for example, 70°C. This allows the relay to resume operation if, for example, the power supply is cut off because a gradual temperature rise exceeds the second threshold, and the temperature of the drive coil drops below the third threshold after the power supply is cut off. Therefore, unlike power supply interruptions caused by a sudden temperature rise, power supply interruptions caused by a gradual temperature rise can be automatically restored to operation by automatically resetting the relay, eliminating the need to dispatch workers and thus reducing the burden on users.

[0015] The power circuit breaker according to the sixth invention is the power circuit breaker according to the fifth invention, wherein the operation recovery determination unit determines that if there is a rapid temperature rise exceeding a first threshold within a predetermined time, the operation of the relay will not be restored. This allows the system to determine, for example, that if the power supply is cut off due to a rapid temperature rise exceeding the first threshold, it may decide that there is a risk in automatically restoring power and, instead of performing the process to restore the relay's operation, take measures such as dispatching a worker.

[0016] The seventh invention is a power circuit breaker according to the first or second invention, wherein the temperature calculation unit calculates the temperature of the drive coil using a first resistor for calculating the temperature of the drive coil while the relay is operating and a second resistor for calculating the temperature of the drive coil when the relay is not operating. This allows the temperature of the drive coil to be calculated using different resistances (first resistor and second resistor) when the relay is operating and when it is not operating, while simultaneously flowing a current less than or equal to the drive current required to drive the drive coil.

[0017] The power circuit breaker according to the eighth invention is a power circuit breaker according to the first or second invention, further comprising a communication unit that transmits information regarding the determination result in the determination unit to the outside. This allows the results of the determination regarding the temperature rise of the relay in the power circuit breaker to be transmitted, for example, to the user or supervisor of the power circuit breaker, prompting them to take appropriate measures.

[0018] The power circuit breaker according to the ninth invention is the same as the power circuit breaker according to the eighth invention, wherein the communication unit changes the destination to which it transmits information regarding the determination result according to the content of the determination result in the determination unit. This allows for appropriate communication with only the necessary contacts, depending on whether the device requires inspection and repair work by a specialist to restore functionality, or if it can be restored automatically.

[0019] The power circuit breaker according to the 10th invention is a power circuit breaker according to the 9th invention, further comprising an operation recovery determination unit that, after the determination unit has determined that the temperature rise exceeds a second threshold and the power supply should be shut off, restores the operation of the relay when the temperature falls below a third threshold for determining operation recovery. If the operation recovery determination unit determines that the operation of the relay should not be restored, the communication unit transmits information regarding the shutdown of the power supply to the electrical equipment management company. This allows the power supply to be interrupted due to a sudden rise in temperature, and the results of the assessment can be communicated to the power circuit breaker maintenance management company.

[0020] The power circuit breaker according to the 11th invention is a power circuit breaker according to the 9th invention, further comprising an operation recovery determination unit that, after the determination unit has determined that the temperature rise exceeds a second threshold and the power supply should be interrupted, restores the operation of the relay when the temperature falls below a third threshold for determining operation recovery. The communication unit, when the operation recovery determination unit determines that the operation of the relay should be restored, transmits information regarding the interruption of the power supply to at least the user of the electrical equipment. This means that in the event of a power outage due to a gradual temperature rise that allows for automatic recovery, no work is required to restore operation, and therefore, only the user needs to be contacted, without needing to contact the maintenance contractor.

[0021] The power interruption system according to the twelfth invention comprises a power circuit breaker according to the first or second invention, a transmitting device, and a cloud server. The transmitting device transmits information regarding the determination result from the determination unit to an external source. The cloud server is connected to the user and management company of the electrical equipment via the internet, and information regarding the determination result is transmitted from the transmitting device to the cloud server. This allows the power circuit breaker to send the determination result regarding the interruption of the relay's power supply to a connected cloud server, enabling users and administrators connected to the cloud server via the internet to share information about the determination result.

[0022] The power interruption system according to the 13th invention is a power interruption system that monitors the temperature of a relay that interrupts the power supply to an electrical device and determines whether or not to interrupt the power supply, and comprises a power circuit breaker and a cloud server that communicates with the power circuit breaker. The power circuit breaker has a relay including a drive coil and a communication unit that communicates with the cloud server. The cloud server has a temperature calculation unit and a determination unit. The temperature calculation unit obtains information about the relay received via the communication unit, calculates the resistance value of the resistance that changes with temperature change when the drive coil included in the relay is considered as a resistor, and calculates the temperature of the drive coil. The determination unit determines whether or not to interrupt the power supply based on the temperature of the drive coil calculated by the temperature calculation unit.

[0023] In this power interruption system, which includes a power circuit breaker with a relay that interrupts the power supply to electrical equipment as needed, and a cloud server, the cloud server considers the drive coil included in the relay as a resistor and utilizes the fact that the resistance value of the drive coil changes with temperature changes to calculate the temperature of the drive coil based on that resistance value and determine whether or not to interrupt the power supply.

[0024] This makes it easy to determine whether or not to cut off the power supply by detecting that the relay has become abnormally hot by calculating the resistance value of the drive coil contained in the relay. As a result, the protective function of the power circuit breaker, including the relay, can be improved without the need to use a separate temperature sensor or other device for temperature detection.

[0025] The protection method for a power circuit breaker according to the 14th invention is a method for a power circuit breaker that monitors the temperature of a relay that interrupts the power supply to an electrical device and determines whether or not to interrupt the power supply, and comprises a temperature calculation step and a determination step. In the temperature calculation step, the temperature of the drive coil is calculated by calculating the resistance value of the resistance that changes with temperature, assuming that the drive coil included in the relay is a resistor. In the determination step, it is determined whether or not to interrupt the power supply based on the temperature of the drive coil calculated in the temperature calculation step.

[0026] In this power circuit breaker, which includes a relay that cuts off the power supply to electrical equipment as needed, the drive coil included in the relay is considered as a resistor. By utilizing the fact that the resistance value of the drive coil changes with temperature changes, the temperature of the drive coil is calculated based on that resistance value, and a decision is made as to whether or not to cut off the power supply. This makes it easy to determine whether or not to cut off the power supply by detecting that the relay has become abnormally hot by calculating the resistance value of the drive coil contained in the relay. As a result, the protective function of the power circuit breaker, including the relay, can be improved without the need to use a separate temperature sensor or other device for temperature detection.

[0027] The power circuit breaker protection program according to the 15th invention is a power circuit breaker protection program that monitors the temperature of a relay that interrupts the power supply to an electrical device and determines whether or not to interrupt the power supply, and causes a computer to execute a power circuit breaker protection method comprising a temperature calculation step and a determination step. In the temperature calculation step, the resistance value of the resistance that changes with temperature changes, assuming that the drive coil included in the relay is a resistor, is calculated and the temperature of the drive coil is calculated. In the determination step, it is determined whether or not to interrupt the power supply based on the temperature of the drive coil calculated in the temperature calculation step.

[0028] In this power circuit breaker, which includes a relay that cuts off the power supply to electrical equipment as needed, the drive coil included in the relay is considered as a resistor. By utilizing the fact that the resistance value of the drive coil changes with temperature changes, the temperature of the drive coil is calculated based on that resistance value, and a decision is made as to whether or not to cut off the power supply. This makes it easy to determine whether or not to cut off the power supply by detecting that the relay has become abnormally hot by calculating the resistance value of the drive coil contained in the relay.

[0029] As a result, the protective function of the power circuit breaker, including the relay, can be improved without the need to use a separate temperature sensor or other device for temperature detection. [Effects of the Invention]

[0030] According to the power circuit breaker of the present invention, the protective function of the power circuit breaker, including the relay, can be improved without using a separate temperature sensor or the like for temperature detection. [Brief explanation of the drawing]

[0031] [Figure 1] A block diagram showing the configuration of a power interruption system including a power circuit breaker according to one embodiment of the present invention. [Figure 2] Figure 1 is an electrical circuit diagram showing the configuration around the drive coil when the power relay included in the power circuit breaker is in operation. [Figure 3] Figure 1 shows an electrical circuit diagram illustrating the configuration around the drive coil of the power relay included in the power circuit breaker during cooling. [Figure 4] Figure 1 shows a graph illustrating the temperature change of the drive coil over time when an abnormality occurs in a power circuit breaker that cannot be restored to operation. [Figure 5] Figure 1 shows a graph illustrating the temperature change of the drive coil over time when an abnormality occurs in a power circuit breaker that can be restored to operation. [Figure 6] A flowchart showing the processing flow of the protection method for the power circuit breaker in Figure 1. [Figure 7]A block diagram showing the configuration of a power interruption system according to another embodiment of the present invention. [Modes for carrying out the invention]

[0032] A power circuit breaker 20 and a power interruption system 1 equipped therewith according to one embodiment of the present invention will be described below with reference to Figures 1 to 6. In this embodiment, unnecessary details may be omitted. For example, detailed explanations of already well-known matters or redundant explanations of substantially identical configurations may be omitted. This is to avoid the following explanation becoming unnecessarily verbose and to facilitate understanding for those skilled in the art. Furthermore, the applicant provides the accompanying drawings and the following description so that those skilled in the art may fully understand the present invention, and not intends to limit the subject matter described in the claims.

[0033] (1) Configuration of power interruption system 1 As shown in Figure 1, the power interruption system 1 according to this embodiment is a system for interrupting the power supplied from the power grid 31 to a load (electrical equipment) 32 based on predetermined conditions, and includes a power interruption module 10 and a cloud server 30.

[0034] As shown in Figure 1, the power interruption module 10 includes a communication module 11 and a power circuit breaker 20. As shown in Figure 1, the communication module 11 is connected to the power circuit breaker 20 and has a communication unit 11a. As shown in Figure 1, the communication unit 11a is connected to the cloud server 30 via wireless communication and transmits data such as the judgment results from the power circuit breaker 20, which will be described later, to the cloud server 30. The communication unit 11a also receives instruction input from the user terminal 40a, the management company terminal 40b, etc., and transmits it to the power circuit breaker 20. Furthermore, the communication unit 11a selectively changes the destination to which it transmits the judgment results and other data according to the content of the judgment results from the power circuit breaker 20, which will be described later.

[0035] As shown in Figure 1, the power circuit breaker 20 is installed between the power grid 31 and the load 32. It determines whether or not to supply the power supplied from the power grid 31 directly to the load 32, and if predetermined conditions are met to ensure safety, it cuts off the power supply to the load 32. The detailed configuration of the power circuit breaker 20 will be described in more detail later.

[0036] (2) Configuration of the power circuit breaker 20 The power circuit breaker 20 according to this embodiment is a device that monitors the temperature of a power relay 21 that interrupts the power supply to a load (electrical equipment, etc.) 32 and determines whether or not to interrupt the power supply. As shown in Figure 1, it comprises a power relay 21, a data processing unit 22, an input 23a, and an output 23b.

[0037] The power relay 21 is a safety device provided to shut off the power supply to the load 32 when a temperature rise exceeding a predetermined threshold is detected, and as shown in Figure 1, it has a drive coil 21a and a switching unit 21b (see Figure 2). The drive coil 21a is one of the components that make up the power relay 21, and is mainly made of copper wire. When the drive coil 21a is considered as a resistor in an electrical circuit, its resistance value changes in response to temperature changes.

[0038] As shown in Figure 2, the power circuit breaker 20 of this embodiment has a resistance value R when the drive coil 21a is considered as a resistor. L By utilizing the fact that this changes in response to temperature changes, the temperature change is detected based on the resistance value of the drive coil 21a. For example, an abnormal temperature rise can be detected, and it is determined whether or not to cut off the power supply to the load 32. As shown in Figure 2, the switching unit 21b is a switching means provided in the power relay 21 that switches between the ON state and the OFF state of the power supply to the load 32.

[0039] As shown in Figure 1, the data processing unit 22 controls the ON / OFF state of the power relay 21, detects the temperature of the power relay 21 (drive coil 21a), and detects the power. The data processing unit 22 also includes a temperature calculation unit 22a, a determination unit 22b, and an operation recovery determination unit 22c. The temperature calculation unit 22a considers the drive coil 21a included in the power relay 21 as a resistor and calculates the resistance value R of the drive coil 21a that changes with temperature. L The temperature of the drive coil 21a is calculated by determining the value of the value.

[0040] Furthermore, the temperature calculation unit 22a calculates the temperature of the drive coil 21a using a resistor (first resistor) R while the power relay 21 is operating. x (See Figure 2) and the resistor (second resistor) R that calculates the temperature of the drive coil 21a when the power relay 21 is not operating. y , R z (See Figure 3) The temperature of the drive coil 21a is calculated using the above. The process for calculating the temperature of the drive coil 21a will be described in detail later.

[0041] The determination unit 22b determines whether or not to cut off the power supply to the load 32 based on the temperature of the drive coil 21a calculated by the temperature calculation unit 22a. More specifically, as shown in Figure 4, if the determination unit 22b detects a rapid temperature rise exceeding a first threshold (e.g., 100°C) within a predetermined time (e.g., 3 seconds), it determines that an abnormality has occurred and decides to cut off the power supply to the load 32 (stop the operation of the power relay 21).

[0042] In this case, the determination regarding a rapid temperature rise may be made based on the condition that the temperature rise per unit time exceeds a predetermined threshold (e.g., 20°C / second), rather than the condition that the temperature rise within a predetermined time (e.g., 3 seconds) exceeds a predetermined first threshold (e.g., 100°C). On the other hand, if the temperature rise does not exceed the first threshold within a predetermined time, the determination unit 22b determines that the state is normal and decides not to interrupt the power supply to the load 32 (maintain operation of the power relay 21).

[0043] Furthermore, if the temperature rise is not a rapid increase as described above, but rather a gradual increase exceeding the second threshold (for example, 100°C) as shown in Figure 5, the determination unit 22b determines that an abnormality has occurred and decides to cut off the power supply to the load 32 (stop the operation of the power relay 21). As shown in Figure 5, the operation recovery determination unit 22c restarts (restores) the operation of the power relay 21 if, after the determination unit 22b has determined that the temperature rise exceeds the second threshold (e.g., 100°C) and that the power supply to the load 32 has been cut off, time has elapsed and the power relay 21 has cooled naturally, and the temperature of the drive coil 21a falls below the third threshold (e.g., 70°C) for operation recovery determination. On the other hand, the operation recovery determination unit 22c determines that if there is a rapid temperature rise exceeding the first threshold (e.g., 100°C) within a predetermined time (e.g., 1 to 3 seconds) as shown in Figure 4, it will not restore the operation of the power relay 21.

[0044] <Temperature calculation process for power relay 21 (drive coil 21a)> The power circuit breaker 20 of this embodiment, with the configuration described above, detects whether the power relay 21 (drive coil 21a) is abnormally hot by calculating the temperature of the drive coil 21a included in the power relay 21, and if it is in an abnormally hot state, it cuts off the power supply to the load 32.

[0045] The method for calculating the temperature of the drive coil 21a is as follows. In other words, the upper temperature limit of the power relay 21 depends on the temperature of the drive coil 21a, which is generally made using copper wire. Here, the temperature rise of the copper windings of a coil, etc., can be determined by the resistance method using the following relation (1).

[0046]

number

[0047] where t: coil temperature before test (°C), T: coil temperature after test (°C), Rt: coil resistance at temperature t (Ω), RT: coil resistance at temperature T (Ω), 234.5: constant for copper. For example, in the case of power relay 21 (Product A) where the resistance of drive coil 21a is 47Ω at 23°C, when the temperature of drive coil 21a changes, the resistance value RT after temperature change (120°C, -5°C) is calculated using the following relational expressions (2) and (3), respectively.

[0048] Note that 120°C is the general maximum rated temperature of power relay 21, and -5°C is the minimum operating temperature of power relay 21.

[0049]

Mathematics

[0050]

Mathematics

[0051] Figure 2 shows an electric circuit using a resistor RX that is used to calculate the temperature of the drive coil 21a when the power relay 21 is in operation. Here, in the electric circuit diagram around the power relay 21 shown in Figure 2, except during transients, the drive coil 21a of the power relay 21 can be regarded as a resistor having a resistance value R L ). Resistance value R L is calculated using the following relational expression (4).

[0052]

Mathematics

[0053] In Figure 2, the resistance value of the resistor (first resistor) Rx, which is used when calculating the temperature of drive coil 21a during operation, is a specified value, V1 / V RL / V CE1This involves obtaining a voltage value using an A / D converter, thereby determining the resistance value R when the drive coil 21a is considered as a resistor. L It is possible to obtain it. Note that I1 represents the current flowing through the resistor when the drive coil 21a is considered as a resistor. V1 represents the voltage applied to the power relay 21. RL This represents the voltage across the drive coil 21a when it is considered as a resistor. RX This refers to the voltage across the resistor (first resistor) Rx used to calculate the temperature of the drive coil 21a while it is operating. CE1 This refers to the voltage applied between ground and point B (transistor 25).

[0054] Here, in the above relation (1), RT = R L Therefore, the resistance value is R L In this case, the 21a temperature of the drive coil is given by the following relation (5), obtained by rearranging relation (1).

[0055]

number

[0056] For example, in the case of the power relay 21 (product A) whose drive coil 21a has a resistance of 47Ω at 23℃, RT = 47(Ω), so the temperature T of the drive coil 21a can be calculated using the following relational equation (6).

[0057]

number

[0058] This allows for the determination of whether the power relay 21 is abnormally hot by directly calculating the temperature T from the resistance value of the drive coil 21a itself, without the need to use a temperature sensor or the like. In the electrical circuit diagram shown in Figure 2, for example, if V1 = 5V, the voltage at point A Va = 2.16V, the voltage at point B Vb = 0.05V, and the resistance Rx = 47Ω, then according to the following relationships (7), (8), and (9), V RL The voltage is 2.89 (V), I1 = 0.045 (A), and the resistance value RL of the drive coil 21a is calculated to be 64.22 (Ω).

[0059]

number

[0060]

number

[0061]

number

[0062] Therefore, the temperature T of the drive coil 21a is calculated to be approximately 117°C using the following relational equation (10).

[0063]

number

[0064] Figure 3 shows an electrical circuit using resistor RX to calculate the temperature of the drive coil 21a when the power relay 21 is not operating (cooling). At this time, the resistance value R when the power relay 21 is in a non-driven state and the drive coil 21a is considered as a resistor is... L To calculate this, a resistor (second resistor) R with a capacitance that the power relay 21 cannot drive is used. y ,R z The resistor R is connected in series with the drive coil 21a, and a test current less than the drive current is passed through it to determine the resistance value R of the drive coil 21a. L Calculate.

[0065] In the case of product A mentioned above, since the drive current of the drive coil 21a is set to 100mA or more, the test current is set to less than 100mA. And then, resistor R y , R z Since this is a specified value, by identifying the voltage values ​​at points C and D, the resistance value R of the drive coil 21a can be determined. L It is possible to calculate this. In the electrical circuit diagram shown in Figure 3, V RZ =V C -V D , V CE1 =V D I²=V RZ / R Z , V Ry =I2·R y , V RL =V1-V Ry -V Rz -V CE1 Therefore, the resistance value R when the drive coil 21a is considered as a resistor is L This is shown by the following relation (11).

[0066]

number

[0067] For example, V1 = 5V, voltage at point C V C =2.4V, voltage at point D V D =0.05V, resistance R y =470Ω, R Z If the value is 470Ω, then the resistance value of the drive coil 21a R is given by the following relation (12). L This is calculated to be approximately 50 ohms.

[0068]

number

[0069] Therefore, the temperature T of the drive coil 21a can be calculated to be approximately 39.43°C using the following relational equation (13).

[0070]

number

[0071] <Protection method for power circuit breaker 20> The protection method for the power relay 21 in this embodiment can be explained as follows using the flowchart shown in Figure 6. In other words, as shown in Figure 6, in step S11, when the user of the power interruption system 1 inputs an operation command to the power circuit breaker 20 using the user terminal 40a or the like, in step S12, the power circuit breaker 20 turns on the power relay 21 and starts supplying power to the load 32 from the power grid 31.

[0072] Next, in step S13, the temperature calculation unit 22a of the power circuit breaker 20 calculates the drive coil 21a from the change in the resistance value of the drive coil 21a of the power relay 21 and monitors whether a rapid temperature rise (see Figure 4) is occurring. Next, in step S14, the determination unit 22b of the power circuit breaker 20 determines whether or not the temperature has reached 100°C, which is set as the critical threshold temperature (first threshold).

[0073] If the calculated temperature of the drive coil 21a has reached the critical threshold temperature (100°C), the process proceeds to step S15; otherwise, the process proceeds to step S18. Next, in step S15, since it was determined in step S14 that there was a rapid temperature rise exceeding the critical threshold temperature, the data processing unit 22 turns the power relay 21 (switching unit 21b) to the OFF state and stops the power supply to the load 32.

[0074] Next, in step S16, the communication unit 11a of the communication module 11 notifies the user terminal 40a owned by the user of the abnormal shutdown of the power relay 21, and in step S17, sends a notification of the abnormality and a request for inspection to the management company terminal 40b owned by the management company. On the other hand, in step S18, since it was determined in step S14 that the temperature of the drive coil 21a had not reached the critical threshold temperature (100°C), the determination unit 22b determines that the temperature rise is gradual.

[0075] Next, in step S19, it is determined whether or not the critical threshold temperature (100°C) has been reached as a result of the gradual temperature increase. At this point, if the temperature of the drive coil 21a, which is gradually rising, reaches the critical threshold temperature (100°C), the process proceeds to steps S20 and S21; otherwise, the process proceeds to step S28. Note that the processes in steps S20 and S21 are performed almost simultaneously.

[0076] Next, in step S20, since it was determined in step S19 that the critical threshold temperature (100°C) had been reached even with a gradual temperature rise, the communication unit 11a of the communication module 11 sends an abnormal shutdown notification only to the user terminal 40a owned by the user. The reason why the communication unit 11a does not send a notification of abnormal shutdown, etc., to the management company's terminal 40b is that if the dangerous threshold temperature (100°C) is reached due to a gradual rise in temperature, the possibility of components such as the power relay 21 being damaged by a short circuit, etc., is low, and it is considered unnecessary for the management company to perform inspection work, etc.

[0077] Next, in step S21, since it was determined in step S19 that the critical threshold temperature (100°C) had been reached even with a gradual temperature rise, the data processing unit 22 turns the power relay 21 (switching unit 21b) to the OFF state and stops the power supply to the load 32. Next, in step S22, the power relay 21 is left in the OFF state for a predetermined time (for example, 30 to 60 minutes) to allow it to cool naturally.

[0078] Next, in step S23, the temperature calculation unit 22a measures the temperature of the power relay 21 while it is not operating (see Figure 3), and the operation recovery determination unit 22c determines whether the temperature of the drive coil 21a has decreased to a predetermined operation recovery temperature (for example, 70°C). If the temperature has dropped to the operating recovery temperature, proceed to step S24; otherwise, proceed to steps S26 and S27.

[0079] Next, in step S24, since it was determined in step S23 that the temperature of the drive coil 21a had dropped to the operating recovery temperature, the data processing unit 22 turns on the switching unit 21b and automatically restores the operation of the power relay 21. Next, in step S25, the communication unit 11a of the communication module 11 sends a notification that the power relay 21 has been automatically restored to only the user terminal 40a owned by the user.

[0080] On the other hand, in step S26, since it was determined in step S23 that the temperature of the drive coil 21a had not decreased to the operating recovery temperature, it was determined that another abnormality had occurred due to environmental factors, etc., and a notification that recovery was impossible was sent to the user terminal 40a owned by the user. In step S27, a notification of the abnormality and a request for inspection was sent to the management company terminal 40b owned by the management company. Next, in step S28, since it was determined in step S19 that the temperature had not reached the critical threshold temperature (100°C) as a result of a gradual temperature rise, it is determined that there is no abnormally high temperature condition, and the operation of the power relay 21 continues.

[0081] [Other embodiments] Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the invention.

[0082] (A) In the above embodiments, examples of the present invention were described as power circuit breakers and their protection methods. However, the present invention is not limited thereto. For example, the present invention may be implemented as a protection program that causes a computer to execute the above-described protection method for power circuit breakers.

[0083] The protection program for this power circuit breaker is stored in the memory (storage unit) installed in the power circuit breaker. The CPU reads the protection program stored in memory and instructs the hardware to execute each step. More specifically, the CPU reads the protection program and executes the temperature calculation step and the judgment step described above, thereby achieving the same effect as above. Furthermore, the present invention may be implemented as a recording medium that stores a protection program for a power circuit breaker.

[0084] (B) In the above embodiment, an example was described in which a temperature calculation unit 22a and a determination unit 22b provided inside the power circuit breaker 20 calculate the temperature of the drive coil 21a included in the power relay 21 and determine whether or not to interrupt the power supply. However, the present invention is not limited thereto.

[0085] For example, as shown in Figure 7, the main entity responsible for calculating the temperature of the drive coil 21a included in the power relay 21 and determining whether or not to cut off the power supply based on the calculated temperature may be a power cut-off system 101 provided on the cloud server 130 side. In other words, as shown in Figure 7, the power interruption system 101 may be configured such that the power circuit breaker 120 is equipped with a data acquisition unit 122 that acquires data regarding changes in resistance from the drive coil 21a included in the power relay 21, and transmits the data to the cloud server 130 via the communication unit 11a of the communication module 11 in the power interruption module 110.

[0086] In this case, the same effect as in the above embodiment can be obtained by having the temperature calculation unit 130a provided in the cloud server 130 calculate the temperature of the drive coil 21a, and the determination unit 130b determine whether or not to cut off the power supply to the load 32 based on the calculated temperature. Furthermore, the operation recovery determination unit 130c may also be provided on the cloud server 130 side.

[0087] (C) In the above embodiment, an example was given in which both the critical threshold temperature (first threshold), which is the upper limit of a rapid temperature rise, and the critical threshold temperature (second threshold), which is the upper limit of a gradual temperature rise, are set to 100°C. However, the present invention is not limited to this. For example, the first threshold and the second threshold may be set to different temperatures. Furthermore, the first and second thresholds may be set to temperatures higher than 100°C or lower than 100°C.

[0088] (D) In the above embodiment, an example was described in which, after a predetermined critical threshold temperature is reached during a gradual temperature rise, the power relay 21 is turned OFF, and then, after a predetermined time has elapsed, the operation of the power relay 21 is restored when the temperature of the drive coil 21a drops to a predetermined operating recovery temperature (70°C). However, the present invention is not limited to this. For example, the operating recovery temperature is not limited to 70°C; it could be a higher temperature such as 90°C, or a lower temperature such as 70°C.

[0089] (E) In the above embodiment, an example was given in which, in order to calculate the temperature of the cooled drive coil 21a when the power relay 21 is in a non-operating state, the temperature of the drive coil 21a is calculated in an electrical circuit including two resistors (second resistor) by applying a current at or below the drive current of the power relay 21. However, the present invention is not limited thereto.

[0090] For example, the second resistor used to calculate the temperature of the drive coil when the relay is not operating does not necessarily have to be two; it could be one or three or more. [Industrial applicability]

[0091] The power circuit breaker of the present invention has the effect of improving the protective function of a power circuit breaker including a relay without the need to use a separate temperature sensor or the like for temperature detection, and is therefore widely applicable to various devices including relays. [Explanation of Symbols]

[0092] 1. Power interruption system 10 Power interruption modules 11. Communication module (transmitter) 11a Communications Department 20 Power circuit breakers 21 Power Relay (Relay) 21a Drive coil 21b Switching section 22 Data Processing Unit 22a Temperature calculation section 22b Judgment part 22c Operation recovery determination unit 23a Input 23b Output 25 transistors 30 Cloud Servers 31 Power grid 32. Load (Electrical Equipment) 40a User terminal 40b Administrator terminal 101 Power Interruption System 110 Power Interruption Module 120 Power Circuit Breaker 122 Data Acquisition Unit 130 Cloud Servers 130a Temperature calculation section 130b Judgment part 130c Operation recovery determination unit R x Resistance (1st resistance) Ry ,R z Resistance (Second Resistance)

Claims

1. A power circuit breaker that monitors the temperature of a relay that cuts off the power supply to electrical equipment and determines whether or not to cut off the power supply, The relay including the drive coil, When the drive coil included in the relay is considered as a resistor, a temperature calculation unit calculates the resistance value of the resistor which changes with temperature, and calculates the temperature of the drive coil. A determination unit determines whether or not to shut off the power supply based on the temperature of the drive coil calculated by the temperature calculation unit, Equipped with, The temperature calculation unit calculates the temperature of the drive coil using a first resistor that calculates the temperature of the drive coil while the relay is operating, and a second resistor that calculates the temperature of the drive coil when the relay is not operating. Power circuit breaker.

2. The determination unit determines that an abnormality has occurred if the temperature rise exceeds a first threshold set to a predetermined temperature within a predetermined time, and decides to shut off the power supply. The power circuit breaker according to claim 1.

3. The determination unit determines that the state is normal and decides not to shut off the power supply if the temperature does not rise above a first threshold set to a predetermined temperature within a predetermined time. A power circuit breaker according to claim 1 or 2.

4. The determination unit determines that an abnormality has occurred if the temperature rise exceeds a second threshold set to a predetermined temperature, and decides to shut off the power supply. A power circuit breaker according to claim 1 or 2.

5. The system further includes an operation recovery determination unit that, after the determination unit has determined that the temperature rise exceeds the second threshold and the power supply should be shut off, restores the operation of the relay if the temperature falls below a third threshold set as a predetermined temperature for operation recovery determination. The power circuit breaker according to claim 4.

6. The operation recovery determination unit determines that if the temperature rise exceeds a first threshold set to a predetermined temperature within a predetermined time, the operation of the relay will not be restored. The power circuit breaker according to claim 5.

7. The system further includes a communication unit that transmits information regarding the determination result from the determination unit to an external source. A power circuit breaker according to claim 1 or 2.

8. The communication unit changes the destination to which it transmits information related to the determination result, according to the content of the determination result in the determination unit. The power circuit breaker according to claim 7.

9. The determination unit further comprises an operation recovery determination unit that, after determining that the temperature rise exceeds a second threshold set to a predetermined temperature and the power supply is to be shut off, restores the operation of the relay if the temperature falls below a third threshold set to a predetermined temperature for operation recovery determination. If the communication unit determines in the operation recovery determination unit that the operation of the relay should not be restored, it transmits information regarding the interruption of the power supply to the electrical equipment management company. The power circuit breaker according to claim 8.

10. The determination unit further comprises an operation recovery determination unit that, after determining that the temperature rise exceeds a second threshold set to a predetermined temperature and the power supply is to be shut off, restores the operation of the relay if the temperature falls below a third threshold set to a predetermined temperature for operation recovery determination. If the communication unit determines in the operation recovery determination unit that the operation of the relay should be restored, it transmits information regarding the interruption of the power supply to at least the user of the electrical equipment. The power circuit breaker according to claim 8.

11. A power circuit breaker according to claim 1 or 2, A transmitting device that transmits information regarding the determination result in the determination unit to an external source, A cloud server is connected to the user and management company of the electrical equipment via the internet, and information regarding the determination result is transmitted from the transmitting device. A power interruption system equipped with [unspecified features].

12. A power interruption system that monitors the temperature of a relay that interrupts the power supply to electrical equipment and determines whether or not to interrupt the power supply, A power circuit breaker, a cloud server that communicates with the power circuit breaker, It is equipped with, The aforementioned power circuit breaker is The relay including the drive coil, A communication unit that communicates with the aforementioned cloud server, It has, The aforementioned cloud server is A temperature calculation unit that obtains information about the relay received via the communication unit, calculates the resistance value of the drive coil which changes with temperature, and calculates the temperature of the drive coil, assuming that the drive coil included in the relay is a resistor, A determination unit determines whether or not to shut off the power supply based on the temperature of the drive coil calculated by the temperature calculation unit, It has, The temperature calculation unit calculates the temperature of the drive coil using a first resistor that calculates the temperature of the drive coil while the relay is operating, and a second resistor that calculates the temperature of the drive coil when the relay is not operating. Power cutoff system.

13. A method for protecting a power circuit breaker, which monitors the temperature of a relay that interrupts the power supply to electrical equipment and determines whether or not to interrupt the power supply, When the drive coil included in the relay is considered as a resistor, the temperature calculation step involves calculating the resistance value of the resistor which changes with temperature, and calculating the temperature of the drive coil. A determination step in which the power supply is determined to be cut off based on the temperature of the drive coil calculated in the temperature calculation step, Equipped with, In the temperature calculation step, the temperature of the drive coil is calculated using a first resistor for calculating the temperature of the drive coil while the relay is operating, and a second resistor for calculating the temperature of the drive coil when the relay is not operating. Methods for protecting power circuit breakers.

14. A protection program for a power circuit breaker that monitors the temperature of a relay that cuts off the power supply to electrical equipment and determines whether or not to cut off the power supply, When the drive coil included in the relay is considered as a resistor, the temperature calculation step involves calculating the resistance value of the resistor which changes with temperature, and calculating the temperature of the drive coil. A determination step in which the power supply is determined to be cut off based on the temperature of the drive coil calculated in the temperature calculation step, Equipped with, In the temperature calculation step, the temperature of the drive coil is calculated using a first resistor for calculating the temperature of the drive coil while the relay is operating, and a second resistor for calculating the temperature of the drive coil when the relay is not operating. A power circuit breaker protection program that instructs a computer to execute the protection methods for power circuit breakers.

Images