Device for preventing misoperation, system for preventing misoperation, and method for preventing misoperation

Abstract

To provide a mis-operation prevention device capable of preventing a mis-operation of an operator during a power-returning operation to secure safety of the operator, and to provide a mis-operation prevention system and a mis-operation prevention method therefor.SOLUTION: A mis-operation prevention device 5 is constituted from a breaker side transmitter 51 attached to an electric pole 7 provided with a breaker 3, a ground side transmitter 52 integrated with a short-circuit ground tool 4, and a receiver 53 carried by an operator H. According to the mis-operation prevention device 5, a signal is sent / received by predetermined short-distance communication means. A determination part 532 provided in the receiver 53 issues alarm as occurrence of a mis-operation in an operational procedure operated by the operator H, when it is determined that reception order of respective signals of a first signal, a second signal and a third signal that are transmitted from the breaker side transmitter 51 and the short-circuit ground tool 4 is different from predetermined reception order.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an accidental operation prevention device, an accidental operation prevention system, and an accidental operation prevention method. Specifically, it relates to an accidental operation prevention device, an accidental operation prevention system, and an accidental operation prevention method that can prevent accidental operations of workers during power restoration work and ensure the safety of workers.

Background Art

[0002] Generally, when performing annual inspections or electrical work on transmission lines, high-voltage power receiving equipment, etc., the work is carried out with the corresponding part in a power-off state. However, even during power-off work, induced current may be induced in the circuit. Therefore, in order to prevent electric shock accidents of workers, after securely short-circuit grounding the target circuit using a short-circuit grounding tool, the inspection work is carried out. By performing short-circuit grounding on the circuit in this way, workers can be protected from electric shock accidents caused by accidental power-on.

[0003] Also, when attaching a short-circuit grounding tool, in order to protect workers from accidental electric shock accidents, its grounding procedure is determined. For example, when inspecting high-voltage power receiving equipment of a customer, first, the short-circuit grounding tool is attached to the grounding terminal, and then, the commercial power system is disconnected by the pole-mounted air switch (PAS) provided at the responsibility demarcation point between the power company and the customer. After releasing the circuit breaker (DS) of the high-voltage power receiving equipment, a short-circuit grounding tool is attached to the primary side of the circuit breaker, and work such as inspection is carried out.

[0004] And, for example, Patent Document 1 discloses a short-circuit grounding tool that can be used according to the correct attachment procedure. Specifically, by attaching the conductive clamp of the short-circuit grounding tool to the grounding terminal, a key member that can be pulled out from the conductive clamp is provided. And if this key member is not fixed to the short-circuit grounding tool, the short-circuit grounding tool cannot be attached to the circuit. Therefore, in order to attach the short-circuit grounding tool to the circuit, first, the worker is guided to the procedure of attaching the conductive clamp to the grounding terminal to obtain the key member, so the worker will not make a mistake in the attachment procedure of the short-circuit grounding tool. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2018-57247 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] Incidentally, once the inspection work is complete, the workers remove the short-circuit grounding device and restore power. However, if the power restoration work is performed with the short-circuit grounding device still attached, the substation's relay may activate when power is restored, potentially causing a power outage in areas that were originally receiving power. Furthermore, the large current (short-circuit current) that flows during a short circuit could cause conductors in high-voltage receiving equipment to overheat and expand, potentially leading to an explosion in the worst-case scenario.

[0007] While the short-circuit grounding device disclosed in Patent Document 1 can guide users through the correct procedure for installing the device, it does not take into account the removal of the device during power restoration, and is still prone to errors.

[0008] The present invention was conceived in view of the above points, and aims to provide a device, a system, and a method for preventing errors in operation that can prevent errors by workers during power restoration work and ensure the safety of workers. [Means for solving the problem]

[0009] To achieve the above objective, the malfunction prevention device of the present invention comprises: a switch-side transmitter installed near a switch provided between a commercial power system and a consumer's power receiving equipment, which transmits a first signal operating in a first pattern; a grounding-side transmitter provided on a short-circuit grounding device connected between the circuit and a grounding point for grounding the circuit, which transmits a second signal operating in a second pattern when the circuit is grounded by the short-circuit grounding device, and transmits a third signal operating in a third pattern when the grounding of the circuit is released; and a receiver carried by a worker, which is responsively connected to the switch-side transmitter and the grounding-side transmitter, which has a storage unit for temporarily storing the signals transmitted from the switch-side transmitter and the grounding-side transmitter, and a determination unit for determining whether the order in which the signals stored in the storage unit are received is in a predetermined order.

[0010] Here, by providing a switch-side transmitter installed near a switch located between the commercial power system and the customer's power receiving equipment, and transmitting a first signal that operates in a first pattern, when a worker approaches a predetermined range of the switch, the first signal can be received by a receiver carried by the worker, as described later.

[0011] Furthermore, by providing a grounding transmitter installed in a short-circuit grounding device connected between the circuit and the grounding point for grounding the circuit, which transmits a second signal operating in a second pattern when the circuit is grounded by the short-circuit grounding device, and transmits a third signal operating in a third pattern when the grounding of the circuit is released, workers can receive signals with different patterns on their portable receivers depending on the grounding status of the circuit.

[0012] Furthermore, by providing a receiver that can be carried by a worker, is freely connected to the switch-side transmitter and the ground-side transmitter, has a storage unit that temporarily stores each signal transmitted from the switch-side transmitter and the ground-side transmitter, and a determination unit that determines whether the order in which the signals stored in the storage unit are received is in a predetermined order, it is possible to determine whether the work performed by the worker was carried out in accordance with a predetermined work procedure based on the order in which the signals stored in the storage unit are received.

[0013] Furthermore, if the receiver receives the first signal, the second signal, the third signal, and the first signal in this order and determines that the work procedure was performed correctly, the determination unit can determine, based on the order in which the signals were received, that the worker performed the following steps correctly: disconnecting the switch from the circuit, connecting the short-circuit grounding device, removing the short-circuit grounding device, and closing the switch.

[0014] Furthermore, if the receiver receives the first signal, the second signal, and the first signal in this order, the determination unit can determine that the short-circuit grounding device is connected and issue an alarm, prompting the worker to remove the short-circuit grounding device. Specifically, the determination unit receives the second signal transmitted when the short-circuit grounding device is connected, but does not receive the third signal transmitted when the short-circuit grounding device is removed, and instead receives the first signal transmitted in close proximity to the switch, thus determining that the worker's procedure is incorrect.

[0015] Furthermore, if the receiver receives the first signal and, after a predetermined period has elapsed since receiving the first signal, receives the first signal again without receiving the second and third signals, the determination unit can issue an alarm, judging that the short-circuit grounding device is not connected or that the grounding transmitter is malfunctioning. In other words, since the determination unit cannot confirm the reception of the second and third signals indicating the connection status of the short-circuit grounding device, it determines that the short-circuit grounding device has been removed for some reason, or that the grounding transmitter itself is malfunctioning.

[0016] Furthermore, if the receiver receives the first signal, the second signal, the third signal, and the second signal again in this order, the determination unit determines that the short-circuit grounding device has been reconnected. If the determination unit clears the reception history of the second and third signals stored in the memory unit, it clears the reception history of the second and third signals that have already been received in the memory unit, allowing the determination to start again from the reception of the second signal. In other words, the determination unit determines that the worker reconnected the short-circuit grounding device for some reason after receiving the third signal and then the second signal again.

[0017] Furthermore, if the switch-side transmitter and the ground-side transmitter are magnetic field type transmitters that generate a magnetic field signal by generating an alternating current in a coil wound around a magnetic core, and the receiver is a magnetic field sensor that receives the magnetic field signal, then stable communication between the transmitter and receiver can be achieved within a predetermined range with a simple configuration.

[0018] Furthermore, if the magnetic field sensor is composed of multiple sensor groups directed in multiple directions around a reference sensor, it is possible to reliably receive the magnetic field signal and prevent a decrease in reception sensitivity, even when a worker is carrying a receiver while working.

[0019] Furthermore, if the switch-side transmitter and the ground-side transmitter transmit radio signals that meet the requirements for low-power radio as defined by the Radio Law, and the receiver receives the radio signals and temporarily stores them in its memory unit, it becomes possible to achieve a highly accurate communication environment within a limited transmission range without requiring license applications or notifications, and with less susceptibility to noise.

[0020] To achieve the above objective, the malfunction prevention system of the present invention comprises a switch installed between a commercial power system and a customer's power receiving equipment; a switch-side transmitter installed near the switch and transmitting a first signal that operates in a first pattern; a short-circuit grounding device connected between the circuit and a grounding point to ground the circuit; a grounding-side transmitter provided on the short-circuit grounding device that transmits a second signal that operates in a second pattern when the circuit is grounded and transmits a third signal that operates in a third pattern when the grounding of the circuit is released; and a receiver carried by a worker, which is responsively connected to the switch-side transmitter and the grounding-side transmitter, and has a storage unit that temporarily stores the signals transmitted from the switch-side transmitter and the grounding-side transmitter, and a determination unit that determines whether the order in which the signals stored in the storage unit are received is in a predetermined order.

[0021] With the above configuration, as described above, it is possible to reliably prevent workers from closing the switch while the short-circuit grounding device is connected, to make workers aware of the prescribed procedures, and to ensure the safety of the workers.

[0022] Furthermore, if the short-circuit grounding device has a gripping portion capable of gripping a grounding member, and the gripping portion includes a first gripping portion and a second gripping portion pivotally supported on the first gripping portion so as to be openable and closable, and the grounding side transmitter has a switching unit that turns on or off a second signal or a third signal transmitted from the grounding side transmitter by pushing or pulling an operating rod that contacts the second gripping portion when the second gripping portion moves in the opening direction, then the short-circuit grounding device and the grounding side transmitter are integrated into a single unit, eliminating the need to attach or detach the grounding side transmitter before starting work or after finishing work, thereby increasing work efficiency.

[0023] Furthermore, if the switch-side transmitter is installed at a predetermined height on the utility pole where the switch is installed, the switch-side transmitter is located along the worker's work route. Therefore, even if the transmission range of the first signal transmitted from the switch-side transmitter is limited, the worker can reliably receive the first signal with a receiver.

[0024] To achieve the above object, the method for preventing incorrect operations according to the present invention includes a first signal that operates in a first pattern within a first work area where an isolator is operated, a second signal that operates in a second pattern when an electric circuit is grounded within a second work area different from the first work area, and a third signal that operates in a third pattern when the grounding of the electric circuit is released within the second work area. When each of these signals is transmitted, a method for determining whether the reception order of each signal is a predetermined order is provided.

[0025] With the above configuration, based on the reception order of the first signal, the second signal, and the third signal, it is possible to determine whether the working procedure of the worker is correct. Therefore, accidents caused by incorrect working procedures by the worker can be prevented, and the safety of the worker can be ensured.

[0026] Also, when the method for determining whether the reception order of each signal is a predetermined order determines that the working procedure has been carried out normally when the first signal, the second signal, the third signal, and the first signal are received in this order, the worker can determine based on the reception status of each signal that each procedure of connecting the short-circuit grounding tool, removing the short-circuit grounding tool, and turning on the isolator has been correctly carried out.

Advantages of the Invention

[0027] The incorrect operation prevention device, incorrect operation prevention system, and incorrect operation prevention method according to the present invention can prevent incorrect operations by workers during power restoration work and ensure the safety of workers.

Brief Description of the Drawings

[0028] [Figure 1] It is a schematic diagram of an incorrect operation prevention system according to a first embodiment of the present invention. [Figure 2] It is a schematic diagram of a transmission antenna of an isolator-side transmitter according to a first embodiment of the present invention. [Figure 3] It is a schematic diagram showing the mounting state of a grounding-side transmitter according to a first embodiment of the present invention. [Figure 4] This is a schematic diagram of a magnetic field sensor in a receiver according to the first embodiment of the present invention. [Figure 5] This is a flowchart illustrating a method for preventing erroneous operation according to the first embodiment of the present invention. [Figure 6] This is a schematic diagram of a malfunction prevention device according to a second embodiment of the present invention. [Modes for carrying out the invention]

[0029] Hereinafter, an error prevention device, an error prevention system, and an error prevention method according to embodiments of the present invention will be described with reference to the drawings to facilitate understanding of the present invention.

[0030] 1. First Embodiment First, an overview of the error prevention system 1 according to the first embodiment of the present invention will be described using Figure 1. The error prevention system 1 according to the first embodiment is a system for preventing worker H from making incorrect operations during power restoration work performed after periodic maintenance and inspection of a customer's power receiving equipment 2, and mainly consists of a switch 3, a short-circuit grounding device 4, and an error prevention device 5.

[0031] [Power receiving equipment] The power receiving equipment 2 is equipment for consumers to receive electricity from the commercial power grid operated by the power utility company, and is a known power supply equipment installed in large factories, plants, high-rise buildings, shared facilities, or commercial facilities. The power receiving equipment 2 houses a disconnector (DS) 21 that opens and closes the circuit 8, and a vacuum circuit breaker (VCB) 22 that extinguishes the arc by diffusing the material constituting the arc discharge that occurs between electrodes when the current is interrupted in a high vacuum. In addition, although not shown, it is equipped with transformers, measuring instruments, capacitors, protective relays, etc.

[0032] [Switch] Switch 3 is a so-called pole-mounted switch (PAS) installed on the top of the utility pole 7 between the commercial power system and the power receiving equipment 2. It is used to temporarily interrupt the flow of current from the commercial power system to the consumer and to isolate the consumer's private premises from the commercial power system. Since the switch 3 has a known configuration, a detailed explanation will be omitted, but for example, it consists of a metal main case and a lid case that closes the opening of the main case, which is detachably attached to the main case. Inside the switch 3 are various power supply devices, including a circuit switching mechanism that enables electrical connection and disconnection, a transformer that supplies power to control equipment that controls the switch 3, a surge arrester to protect various power supply equipment from transient abnormally high voltages caused by lightning, and a voltage detection capacitor that serves as a voltage detection sensor for the power distribution path.

[0033] Here, switch 3 does not necessarily have to be a pole-mounted switch. For example, in facilities that use underground power distribution lines, a ground-mounted switch (UGS) can be used instead of a pole-mounted switch. However, for the sake of explanation, the following explanation will assume that switch 3 is a pole-mounted switch.

[0034] [Short-circuit grounding device] The short-circuit grounding device 4 is a known short-circuit grounding device used to short-circuit a designated work point in the circuit 8 in order to ensure safety during work such as erroneous power transmission when shutting off power during maintenance and inspection of the power receiving equipment 2, by opening the switch 3 and cutting off power from the commercial power system.

[0035] The short-circuit grounding device 4 consists of a high-voltage gripping part 41 that attaches to the circuit 8, a grounding-side gripping part 42 that attaches to the grounding wire 9 (for example, the earth, a grounding terminal connected to the earth, or a grounded conductive member, etc.), and a cable 43 that connects the high-voltage gripping part 41 and the grounding-side gripping part 42. For the sake of explanation, the high-voltage gripping part 41 shown in Figure 1 is represented as a short-circuit grounding device in a single-line diagram. However, in the case of a short-circuit grounding device for three-phase AC, one end of the cable 43 branches into three short-circuit wires, and the high-voltage gripping part 41 is connected to each short-circuit wire.

[0036] Since the short-circuit grounding device 4 has a known configuration, a detailed explanation will be omitted, but as shown in Figure 3, the high-voltage side gripping portion 41 and the grounding side gripping portion 42 are so-called alligator clips consisting of first gripping portions 411, 421 and second gripping portions 412, 422 pivotally supported to the first gripping portions 411, 421 so as to be openable and closable, and the circuit 8 and the grounding wire 9 can be gripped with these clips.

[0037] [Error prevention device] The error prevention device 5 is a short-range communication device for determining whether a series of grounding operations performed by worker H during inspection work on the power receiving equipment 2 are being carried out according to a predetermined procedure, and consists of a switch-side transmitter 51, a grounding-side transmitter 52, and a receiver 53.

[0038] <Switch-side transmitter> The switch-side transmitter 51 is installed at a predetermined height (approximately 1m from the ground) on the utility pole 7 where the switch 3 is installed, and a signal operating in a first pattern (first signal) is constantly transmitted within a radius of 1m centered on the switch-side transmitter 51. When worker H approaches the utility pole 7 where the switch-side transmitter 51 is installed in order to operate the switch 3, the first signal can be received by the receiver 53 carried by worker H, as described later.

[0039] Here, the switch-side transmitter 51 does not necessarily need to be installed at a height of about 1 meter from the ground. However, worker H often wears the receiver 53 on his waist to avoid obstructing his work during inspections. In this case, considering the average height of an adult, installing the switch-side transmitter 51 at waist height, about 1 meter from the ground, ensures that worker H can reliably receive the first signal when he approaches the utility pole 7.

[0040] Furthermore, the transmission range of the first signal does not necessarily have to be within a 1m radius from the switch-side transmitter 51; depending on the conditions at the work site, the transmission range can be narrower or wider than 1m. The upper limit of the transmission range of the first signal is a range that does not cause interference with the second signal or the third signal transmitted from the ground-side transmitter 52, which will be described later.

[0041] When the switch-side transmitter 51 is turned ON (not shown), it continuously transmits the first signal. When worker H performs inspection work on the power receiving equipment 2, he first installs the switch-side transmitter 51 on the utility pole 7 and turns ON the power to the switch-side transmitter 51 so that the first signal is transmitted continuously during the work period. After the inspection work on the power receiving equipment 2 is completed, he turns OFF the power to the switch-side transmitter 51, removes the switch-side transmitter 51 from the utility pole 7 and retrieves it, thus completing the work.

[0042] Figure 2 is a schematic diagram showing the transmitting antenna 512 included in the switch-side transmitter 51. As shown in the lower part of Figure 2(a) (front view), the transmitting antenna 512 is a short-range communication device consisting of an electromagnetic coupling system, which is constructed by winding a coil 513 along the long axis of a bobbin 514. When a signal current output from a signal transmitter 511 incorporated into the internal circuit of the switch-side transmitter 51 flows through the coil 513, a magnetic field is induced along the long axis of the bobbin 514, and this magnetic field is transmitted as a magnetic field signal, forming a first signal consisting of a first pattern.

[0043] As shown in the upper diagram (plan view) of Figure 2(a), the first signal is transmitted within a 360-degree range centered on the transmitting antenna 512, thereby increasing the receiving sensitivity of the receiver 53. Furthermore, the operation pattern and transmission range of the first signal can be freely changed by altering the number of coil turns or the applied current.

[0044] Furthermore, as shown in Figure 2(b), the antenna magnetic core 515 can also be installed along the long axis of the bobbin 514. Compared to the case where the coil 513 is constructed using only the bobbin 514, the coil 513 can be made smaller. In addition, by changing the length of the antenna magnetic core 515, it becomes possible to freely change the output signal of the magnetic field signal.

[0045] Alternatively, as shown in Figure 2(c), multiple transmitting antennas 512 may be arranged vertically (in the example in Figure 2(c), three transmitting antennas are arranged). In this case, the signal current output from the signal transmitter 511, which is incorporated into a circuit common to the three transmitting antennas 512, 512a, and 512b, flows through the coils of each transmitting antenna 512, 512a, and 512b, inducing a magnetic field along the long axis of the antenna magnetic core 515, thereby expanding the reception range in the vertical direction.

[0046] <Ground-side transmitter> As shown in Figure 1, the grounding side transmitter 52 has the same configuration as the switch side transmitter 51 described above, including a transmitting antenna 522 and a signal transmitter 521 that transmits a signal current to the transmitting antenna 522. A loop circuit is formed for the short-circuit grounding device 4 by switching the contact 523 ON / OFF. Note that the transmitting antenna 522 of the short-circuit grounding device 4 is the same as the configuration of the switch side transmitter 51 described above, so its explanation is omitted.

[0047] When worker H turns on a power button (not shown) to power on the grounding transmitter 52, and one of the two lead wires extending from the grounding transmitter 52, lead wire 524a, is connected to the high-voltage gripping part 41 of the short-circuiting grounding device 4, and the other lead wire 524b is connected to the grounding gripping part 42 of the short-circuiting grounding device 4, the contacts turn ON, forming a closed loop circuit, and a signal operating in the second pattern (second signal) is transmitted.

[0048] On the other hand, when the lead wires 524a and 524b connected to the high-voltage gripping section 41 or the grounding gripping section 42 are opened, the contacts turn OFF and the internal circuit becomes open. At this time, the grounding transmitter 52 transmits a signal that operates in the third pattern (the third signal) for a certain period of time. That is, the grounding transmitter 52 transmits the second signal and the third signal, respectively, depending on the short-circuit grounding state of the short-circuit grounding device 4.

[0049] The contact 523 in the internal circuit of the grounding side transmitter 52 is switched ON / OFF by the grounding unit 6, which is linked to the opening and closing operations of the high-voltage side gripping part 41 and the grounding side gripping part 42. As shown in Figure 3, the grounding unit 6 consists of a fixed plate 61 with a through hole 62 formed at one end, a slide plate 64 that is slidably attached to the fixed plate 61 via a spring 63 that biases toward one end of the fixed plate 61, and an operating rod 65 that can press a switch 66 and is integrally formed with the slide plate 64.

[0050] The grounding unit 6 is attached to the high-pressure side gripping section 41 by inserting a bolt and nut through the through hole 62 at one end of the fixing plate 61 and fixing it to the first gripping sections 411 and 421, at which point one end of the operating rod 65 comes into contact with the second gripping sections 412 and 422. When the high-pressure side gripping section 41 is operated to move the second gripping sections 412 and 422 in the opening direction relative to the first gripping sections 411 and 421, the slide plate 64 slides against the biasing force of the spring 63 (see blowout diagrams (a) and (b) in Figure 3).

[0051] As the slide plate 64 slides, the operating rod 65, which is in contact with the second gripping parts 412 and 422, presses the switch 66, turning the switch 66 of the grounding unit 6 ON. When the electric circuit 8 is gripped by the high-voltage gripping part 41, the operating rod 65 remains in the ON state, pressing the switch 66. The attachment of the grounding unit 6 to the grounding-side gripping part 42 is similar; when the grounding-side gripping part 42 is operated to grip the grounding wire 9, the switch 66 of the grounding unit 6 turns ON.

[0052] When either of the switches 66 on the grounding unit 6 is turned ON, the contacts in the internal circuit of the grounding transmitter 52 are turned ON, and a second signal is transmitted from the grounding transmitter 52. On the other hand, when both the high-voltage gripping part 41 and the grounding gripping part 42 are removed from the circuit 8 or grounding wire 9 they are gripping, the slide plate 64 slides in the direction of the biasing force of the spring 63, releasing the pressing state of the operating rod 65 and the switch 66, and the switch 66 turns OFF. When either of the switches 66 turns OFF, the contact 523 in the internal circuit of the grounding transmitter 52 turns OFF, and a third signal is transmitted from the grounding transmitter 52.

[0053] Here, it is not necessarily required that the contact 523 in the internal circuit of the grounding transmitter 52 be turned OFF when either the high-voltage grip 41 or the grounding grip 42 is removed. For example, the contact may be configured to turn OFF when both the high-voltage grip 41 and the grounding grip 42 are removed. By configuring it in this way, if either the high-voltage grip 41 or the grounding grip 42 is accidentally detached, a third signal is transmitted, which prevents a misdiagnosis that the work is proceeding according to the prescribed procedure.

[0054] <Receiver> The receiver 53 is a device carried by worker H on part of their body to receive the first signal, second signal, and third signal (the first to third signals are collectively simply referred to as "signals") transmitted from the switch-side transmitter 51 and the ground-side transmitter 52, respectively. The receiver mainly consists of a magnetic field sensor 534 that receives the signals, a storage unit 531 that temporarily stores the received signals, a determination unit 532 that determines whether the signals were received in a predetermined order, and an alarm output unit 533 that outputs an alarm to the outside according to the determination result of the determination unit 532.

[0055] The magnetic field sensor 534 is composed of a total of five sensor groups, for example, as shown in FIG. 4(a), including the second magnetic field sensor 534b, the third magnetic field sensor 534c, the fourth magnetic field sensor 534d, and the fifth magnetic field sensor 534e, which are arranged at equal angles (at intervals of 90 degrees in FIG. 4(a)) around the first magnetic field sensor 534a serving as a reference in a plan view. Note that, as shown in FIG. 4(b), as the configuration of the sensor group, the second magnetic field sensor 534b, the third magnetic field sensor 534c, the fourth magnetic field sensor 534d, and the fifth magnetic field sensor 534e may be evenly arranged in the left - right direction facing the paper surface with the first magnetic field sensor 534a as a reference.

[0056] Here, necessarily, the magnetic field sensor 534 does not necessarily have to be composed of a plurality of sensor groups as described above, and it may be composed of a single magnetic field sensor 534. However, since the operator H performs inspection work and the like while carrying the receiver 53, the position of the receiver 53 is not determined, and depending on the posture of the operator H during the inspection work, the reception sensitivity of the signal may become weak. Therefore, from the viewpoint of enhancing the reception sensitivity, it is preferable that the magnetic field sensor 534 is composed of a plurality of sensor groups.

[0057] When the magnetic field sensor 534 receives a signal, the sensitivity received by each magnetic field sensor 534 is compared with a threshold value stored in advance. If the sensitivity of any one of the magnetic field sensors 534 in the sensor group exceeds the threshold value, the receiver 53 is determined to have received the signal.

[0058] The above is the configuration of the misoperation prevention system 1 according to the first embodiment of the present invention. Next, a misoperation prevention method during the inspection work of the power receiving equipment 2 using the misoperation prevention device 5 will be described based on the flowchart of FIG. 5.

[0059] <S101: Power outage work> When inspecting the power receiving equipment 2, the power supply from the commercial power system is stopped by opening the switch 3 provided at the responsibility demarcation point between the circuit 8 of the commercial power system and the power receiving equipment 2. At this time, the operator H attaches the transmitter 51 on the switch side to a predetermined height position of the utility pole 7 where the switch 3 is installed and turns on the power supply of the transmitter 51 on the switch side.

[0060] <S102: Reception determination of the first signal> When the power supply of the transmitter 51 on the switch side is turned on, the first signal is transmitted. Then, the receiver 53 performs reception determination of this first signal. When the receiver 53 receives the first signal, the reception history is temporarily stored in the storage unit 531 of the receiver 53.

[0061] <S103: Short - circuit operation> After opening the switch 3 and completing the power outage work, the operator H moves to the work area where the power receiving equipment 2 to be inspected is located and connects the short - circuit grounding tool 4 integrated with the transmitter 52 on the grounding side. The connection of the short - circuit grounding tool 4 is to connect the high - voltage side gripping part 41 to the primary side of the circuit breaker 21 and connect the grounding side gripping part 42 to the grounding wire 9.

[0062] <S104: Reception determination of the second signal> Due to the connection of the short - circuit grounding tool 4, the contact of the internal circuit of the transmitter 52 on the grounding side is turned on, and the second signal is transmitted. Then, the receiver 53 performs reception determination of this second signal. When the receiver 53 receives the second signal, the reception history is temporarily stored in the storage unit 531 of the receiver 53.

[0063] <S105: Inspection work> After receiving the second signal, the operator H starts the inspection work of the power receiving equipment 2.

[0064] <S106: Reception determination of the third signal> When the inspection work of the power receiving equipment 2 is completed, prior to the power restoration work, the worker H removes the short-circuit grounding tool 4. When the short-circuit grounding tool 4 is removed, the contacts of the internal circuit of the grounding-side transmitter 52 are turned off, and a third signal is transmitted. Then, in the receiver 53, the reception determination of this third signal is performed. When the receiver 53 receives the third signal, the reception history is temporarily stored in the storage unit 531 of the receiver 53.

[0065] <S107: Reception determination of the second signal> When the third signal is received in S106, subsequently, the reception determination of the second signal is performed. In S107, if the receiver 53 determines that it has received the second signal (when "YES" in S107), it is determined that the short-circuit operation of the short-circuit grounding tool 4 has been performed again due to, for example, either the high-voltage side gripping portion 41 or the grounding-side gripping portion 42 of the short-circuit grounding tool 4 being disengaged. Then, the reception histories of the second signal and the third signal up to now are cleared, the second signal received the second time is stored in the storage unit 531, and the process returns to S105. On the other hand, if it is determined in S107 that the second signal has not been received (when "NO" in S107), the process proceeds to S108.

[0066] <S108: Reception determination of the first signal> Subsequently, the reception determination of the first signal is performed. The worker H who has completed the inspection work on the power receiving equipment 2 moves to the utility pole 7 where the switch 3 is installed in order to perform the power restoration work. When approaching the work area where the first signal is transmitted, the receiver 53 receives the first signal.

[0067] <S109: Power restoration work> If it is determined in S108 that the receiver 53 has received the first signal, the determination unit 532 determines that the work process by the worker H has been carried out in accordance with the correct procedure predetermined based on the reception history of the signals up to now (in the order of the first signal, the second signal, the third signal, and the first signal). As a result, the worker H can turn on the switch 3 and execute the power restoration work.

[0068] <S110: Reception determination of the first signal> On the other hand, if in S104 the second signal transmitted when the short-circuit grounding device is connected is not received (determined as "NO" in S104), and the first signal is received in S110, the determination unit 532 determines, based on the signal reception history up to that point (receiving the first signal, then receiving the first signal again), that the short-circuit grounding device 4 is not connected or that the grounding side transmitter 52 is malfunctioning, and an alarm is issued from the receiver 53 (S111). When the alarm is issued, worker H performs the short-circuit operation again using the short-circuit grounding device 4.

[0069] Furthermore, if the third signal transmitted when the short-circuit grounding device is removed is not received in S106 (determined as "NO" in S106), and the first signal is received in S112, the determination unit 532, based on the history of signals received so far (received in the order of the first signal, the second signal, and the first signal), determines that worker H will perform the power restoration work with the short-circuit grounding device 4 still connected, and the receiver 53 issues an alarm to notify the worker that the short-circuit grounding device has been forgotten to be removed (S113).

[0070] As described above, the determination unit 532, based on the signal history stored in the memory unit 531, issues an alarm if it determines that the order in which signals are received is not in a predetermined order (the order of the first signal, the second signal, the third signal, and the first signal). This prevents accidents caused by performing power restoration work while the short-circuit grounding device 4 is connected, and also enables fault diagnosis of the grounding side transmitter 52.

[0071] The above describes the method for preventing erroneous operation according to the first embodiment of the present invention. However, for example, the determination unit 532 may also issue an alarm when it determines that the signals have been received in a predetermined order. In this case, by changing the type of alarm depending on whether the signals were received in a predetermined order or not, worker H can instantly grasp whether the work procedure performed so far was correct or incorrect.

[0072] Furthermore, the means of notifying the alarm emitted from the receiver 53 may include sounds such as a buzzer, voice messages, display messages, flashing lights, or vibrations. In addition, the output signals of these alarms may be transmitted to a mobile terminal held by worker H, and the alarm may be issued through the mobile terminal.

[0073] Furthermore, when the receiver 53 receives the first signal, the second signal, and the third signal, an alarm may be issued to notify worker H that these signals have been received. In this case, it is preferable to change the type of alarm issued when each signal is received.

[0074] 2. Second Embodiment Next, the malfunction prevention device 5 according to the second embodiment of the present invention will be described with reference to Figure 6. In the following description, the same reference numerals will be used for components common to the first embodiment, and redundant explanations will be omitted, with only the differing components being described in detail.

[0075] The malfunction prevention device 5 according to the second embodiment differs from the first embodiment in the communication method between the switch-side transmitter 51, the ground-side transmitter 52, and the receiver 53, but the other configurations are the same. That is, the communication method of the malfunction prevention system 1 according to the second embodiment employs a radio wave method using 300MHz band low-power radio.

[0076] The switch-side transmitter 51 is equipped with a radio transmitter 516 that transmits a first signal, and the ground-side transmitter 52 is equipped with a radio transmitter 524 that transmits a second signal. The receiver 53 is equipped with a radio receiver 535 for receiving the first signal and the second signal.

[0077] Thus, by adopting a radio wave system using the 300MHz band low-power radio as the communication method, a radio license based on the Radio Law is not required, making it highly convenient. Furthermore, it is less susceptible to noise interference, enabling a highly accurate communication environment within a limited transmission range.

[0078] As described above, the malfunction prevention device, malfunction prevention system, and malfunction prevention method according to the present invention can prevent malfunctions by workers during power restoration work and ensure the safety of workers. [Explanation of Symbols]

[0079] 1. Error Prevention System 2. Power receiving equipment 21 Disconnector 22 Vacuum circuit breaker 3 Switch 4 Short-circuit grounding device 41 High-pressure side gripping section 411 First gripping part 412 Second gripping part 42 Ground side grip part 421 First gripping part 422 Second gripping part 43 Cables 5 Misoperation prevention device 51 Switch-side transmitter 511 Signal Transmitter 512, 512a, 512b transmitting antennas 513 Coil 514 Bobbin 515 Antenna magnetic core 516 Radio Transmitter 52 Ground-side transmitter 521 Signal Transmitter 522 Transmitting Antenna 523 Contacts 524 Radio Transmitter 53 Receiver 531 Storage section 532 Judgment section 533 Alarm output section 534 Magnetic field sensor 534a First magnetic field sensor 534b Second magnetic field sensor 534c Third Magnetic Field Sensor 534d Fourth magnetic field sensor 534e Fifth magnetic field sensor 535 Radio receiver 6. Grounding Unit 61 Fixed plate 62 Through hole 63 Spring 64 sliding plates 65 Operating Rod 66 switches 7 Utility pole 8 Electric circuit 9 Ground wire H worker

Claims

1. A switch-side transmitter is installed near a switch located between the commercial power system and the customer's power receiving equipment, and transmits a first signal that operates in a first pattern. A grounding transmitter is provided on a short-circuit grounding device connected between the circuit and the grounding point for grounding the circuit, and transmits a second signal that operates in a second pattern when both the high-voltage side gripping portion and the grounding side gripping portion of the short-circuit grounding device are closed, and transmits a third signal that operates in a third pattern when at least one of the high-voltage side gripping portion and the grounding side gripping portion is open. The system includes a receiver that is carried by a worker, is connected to the switch-side transmitter and the ground-side transmitter so as to be able to communicate with each other, has a storage unit for temporarily storing each signal transmitted from the switch-side transmitter and the ground-side transmitter, and a determination unit for determining whether the order in which the signals stored in the storage unit are received is in a predetermined order. Misoperation prevention device.

2. The determination unit, If the receiver receives the first signal, the second signal, the third signal, and the first signal in this order, it determines that the work procedure has been performed correctly. The malfunction prevention device according to claim 1.

3. The determination unit, If the receiver receives the first signal, the second signal, and the first signal in this order, it determines that the short-circuit grounding device is connected and issues an alarm. An error prevention device according to claim 1 or claim 2.

4. The determination unit, If the receiver receives the first signal and, after a predetermined period has elapsed, receives the first signal again without receiving the second signal or the third signal, it determines that the short-circuit grounding device is not connected or that the grounding side transmitter is malfunctioning and issues an alarm. An error prevention device according to claim 1 or claim 2.

5. The determination unit, If the receiver receives the first signal, the second signal, the third signal, and the second signal in this order, it determines that the short-circuit grounding device has been reconnected, and clears the reception history of the second signal and the third signal from the signal reception history stored in the memory unit. An error prevention device according to claim 1 or claim 2.

6. The switch-side transmitter and the ground-side transmitter are magnetic field type transmitters that generate a magnetic field signal by generating an alternating current in a coil wound around a magnetic core, and the receiver is a magnetic field sensor that receives the magnetic field signal. The magnetic field sensor is composed of multiple sensor groups that point in multiple directions different from each other, with a reference sensor at its center. An error prevention device according to claim 1 or claim 2.

7. The switch-side transmitter and the ground-side transmitter transmit radio signals that meet the requirements for low-power radio signals as defined by the Radio Law. The receiver receives the radio signal and temporarily stores it in the storage unit. An error prevention device according to claim 1 or claim 2.

8. A switch installed between the commercial power grid and the customer's power receiving equipment, A switch-side transmitter installed near the switch and transmitting a first signal that operates in a first pattern, A short-circuit grounding device connected between the circuit and the grounding point for grounding the circuit, A grounding transmitter provided on the short-circuit grounding device transmits a second signal that operates in a second pattern when both the high-voltage gripping portion and the grounding gripping portion of the short-circuit grounding device are closed, and transmits a third signal that operates in a third pattern when at least one of the high-voltage gripping portion and the grounding gripping portion is open. The system includes a receiver that is carried by a worker, is connected to the switch-side transmitter and the ground-side transmitter so as to be able to communicate with each other, has a storage unit for temporarily storing each signal transmitted from the switch-side transmitter and the ground-side transmitter, and a determination unit for determining whether the order in which the signals stored in the storage unit are received is in a predetermined order. A system to prevent accidental operation.

9. The high-pressure side gripping portion and the grounding side gripping portion each include a first gripping portion capable of gripping a grounding member and a second gripping portion pivotally supported to the first gripping portion so as to be openable and closable, The ground-side transmitter has a switching mechanism that, when the second gripping portion moves in the opening direction, allows the second signal or the third signal transmitted from the ground-side transmitter to be turned ON or OFF by pushing or pulling an operating rod that contacts the second gripping portion. The error prevention system according to claim 8.

10. The switch-side transmitter is installed at a predetermined height on the utility pole where the switch is installed. The error prevention system according to claim 8 or claim 9.

11. When a first signal is transmitted in a first pattern within a first work area where the switch is operated, a second signal is transmitted in a second pattern when both the high-voltage grip and the ground-side grip of a short-circuit grounding device are closed within a second work area different from the first work area, and a third signal is transmitted in a third pattern when at least one of the high-voltage grip and the ground-side grip is opened within the second work area, The system includes a method for determining whether the order in which each of the aforementioned signals is received is in a predetermined order. How to prevent incorrect operation.

12. A method for determining whether the order in which each of the aforementioned signals is received is a predetermined order. If the first signal, the second signal, the third signal, and the first signal are received in this order, it is determined that the work procedure has been performed correctly. The method for preventing erroneous operation according to claim 11.

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