JP4045571B2 - Coil abnormality monitoring device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a coil abnormality monitoring device that detects a coil abnormality.
[0002]
[Prior art]
Conventionally, this type of coil abnormality monitoring apparatus has a coil impedance between a DC power supply terminal and an important coil (hereinafter referred to as a monitoring target coil) that will cause a serious accident if it is disconnected and does not operate. A large disconnection detection relay is provided, and a current smaller than the operating current of the coil is passed through this relay. The coil to be monitored is set so that a current smaller than the minimum operating current flows. When the monitoring target coil is disconnected, the disconnection of the coil is detected by stopping energization of the disconnection detection relay, the contact of the disconnection detection relay provided in the lamp circuit is opened or closed, the lamp is turned off, and the monitoring target coil is turned off. Disconnection detection is performed.
A conventional example is shown in FIG. The contact b is pulled out from the coil to be monitored and the disconnection detection relay, respectively, and a disconnection detection signal is output. When the disconnection detection relay and the coil to be monitored are energized, the respective contacts are opened, and in the non-excited state, the respective contacts are closed.
Hereinafter, detection of disconnection of the monitoring target coil will be described in accordance with normality / disconnection of the monitoring target coil and presence / absence of a trip command.
(1) When the monitoring target coil is normal and no trip command is issued The disconnection detection relay that operates at a current smaller than the minimum operating current of the monitored coil is in an excited state, and the b contact of the disconnection detection relay is opened, No disconnection detection signal is output. At this time, since a current smaller than the minimum operating current flows through the monitored coil, it is in a non-excited state and the b-contact of the monitored coil is closed.
(2) When the monitoring target coil is disconnected and the trip command is not issued Since the monitoring target coil is disconnected, no current flows through the disconnection detection relay, and there is no excitation, so b of the disconnection detection relay Since the contact is closed and no current flows through the monitoring target coil and the coil is not excited, the contact b of the monitoring target coil is closed, so that the disconnection detection signal is output.
(3) When the coil to be monitored is normal and the trip command is issued The contact that is turned on by the trip command causes no current to flow through the disconnection detection relay, so that the b contact of the disconnection detection relay is closed. However, since the coil to be monitored is excited, the b contact of the coil to be monitored is opened, and no disconnection detection signal is output.
(4) When the coil to be monitored is disconnected and a trip command is issued The contact that is turned on by the trip command causes no current to flow through the disconnection detection relay, and the b contact of the disconnection detection relay is closed. Since the monitoring target coil is disconnected and is not excited, the b contact of the monitoring target coil is also closed, and a disconnection detection signal is output.
[0003]
[Problems to be solved by the invention]
In the case of the conventional example, since a disconnection detection relay is used, even if an abnormality occurs in either the monitored coil or the disconnection detection relay, such as a crack or a crack, an abnormality is detected, and either coil is abnormal. In addition, if there are multiple coils to be monitored, it is necessary to provide a disconnection detection relay for each coil to be monitored, so it is not easy to add or delete coils to be monitored was there.
[0004]
An object of the present invention is to monitor a plurality of monitoring target coils, identify an abnormal coil, and facilitate addition and deletion of the monitoring target coil.
[0005]
[Means for Solving the Problems]
In order to solve the above problem, when monitoring abnormalities of a plurality of coils to be monitored connected in parallel between power buses of the main circuit, a constant voltage power source different from the main circuit or another constant current power source, A diode that prevents the inflow of reverse current, a current measuring device or voltage measuring device, and a plurality of changeover switches for switching a plurality of coils to be monitored, and current information or voltage information detected by the current measuring device or voltage measuring device A coil abnormality monitoring device that performs abnormality monitoring of a plurality of coils to be monitored based on one unit ,
A circuit switching means is provided for switching a changeover switch between a power bus different from the power bus of the main circuit,
The circuit switching means includes, for each of the plurality of changeover switches, a self-holding type relay that operates the changeover switch, a contact that forms a self-holding circuit that self-holds the relay when the relay is excited, Having a timer connected in series, connecting the timer contact and a self-holding relay in series, and connecting the timer in parallel with the series connected circuit,
When abnormality monitoring the first monitoring target coil, the first relay and the first timer is excited, the excitation of the first relay at this time is a predetermined time set by the first timer, the predetermined time Until the first monitoring coil is abnormally monitored until
Subsequently, the abnormality monitoring of the second monitoring target coil is performed on the condition that the predetermined time set by the first timer has elapsed, with the first timer connected in series with the second relay and the second timer. exciting the second relay and the second timer to close the contacts, the excitation of the second relay in this case is a predetermined time set in the second timer, the second until the predetermined time elapses Monitor the monitored coil for abnormalities,
Subsequently, abnormality monitoring of the third and subsequent monitoring target coils is performed in the same manner, and a plurality of monitoring target coils are automatically switched to perform abnormality monitoring.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an embodiment of a coil abnormality monitoring apparatus of the present invention. In FIG. 1, an abnormality monitoring device (one-dot chain line portion) 21 includes a changeover switch portion (chain line portion) 16 on a plurality of monitoring target coils 4 connected to the main circuit of a positive power supply bus 1 and a negative power supply bus 2. A current measuring device 12 that measures the current flowing through the circuit and a diode 15 that prevents inflow of reverse current are connected, and a constant voltage power supply 11 that is different from the main circuit is connected to the current measuring device 12 and diode 15. The constant voltage power supply 11 is set to a constant voltage such that a current smaller than the operating current of the coil flows through the coil 4 to be monitored. The changeover switch unit 16 connects a changeover switch to each of the plurality of monitoring target coils 4, and switches the changeover switch to turn on and off the target coil 4.
When the coil 4 to be monitored is normal, a certain current flows from the constant voltage power supply 11 to the coil 4 via the diode 15, the changeover switch unit 16, and the current measuring device 12. The current measuring device 12 detects this current and uses the current information of the current measuring device 12 to determine that the coil 4 to be monitored is normal. On the other hand, when an abnormality such as a crack or a crack occurs in the coil 4 to be monitored, the current flowing through the circuit is reduced due to an increase in the impedance of the coil 4. Further, when the coil 4 is completely disconnected, the current flowing through the circuit becomes zero. The current measuring device 12 detects this current and uses the current information of the current measuring device 12 to determine that the monitored coil 4 is abnormal.
In addition, in order to identify a coil having an abnormality among the plurality of coils 4 to be monitored, the circuit is switched by the changeover switch of the changeover switch unit 16 and the abnormality is monitored. Thereby, it is possible to monitor and detect abnormalities of a plurality of coils with one abnormality monitoring device, and further to identify the coil in which the abnormality is detected.
In this embodiment, in order to add or delete one monitoring target coil, it is sufficient to add or delete two cables. Therefore, the monitoring target coil can be easily added or deleted.
[0007]
FIG. 2 shows another embodiment of the present invention. In FIG. 2, the abnormality monitoring device (one-dot chain line portion) 22 includes a changeover switch portion (chain line portion) 16 in a plurality of monitoring target coils 4 connected to the main circuit of the positive power supply bus 1 and the negative power supply bus 2. A voltage measuring device 14 for measuring the voltage applied to the coil is connected to a diode 15 for preventing the inflow of reverse current, and a constant current power supply 13 different from the main circuit is connected to the voltage measuring device 14 and the diode 15. . The constant current power source 13 is set to a constant current such that a current smaller than the operating current of the coil flows through the monitored coil 4. The changeover switch unit 16 connects a changeover switch to each of the plurality of monitoring target coils 4 and switches the changeover switch to turn on and off the target coil 4.
When the monitoring target coil 4 is normal, a certain voltage is applied to the coil 4 from the constant current power supply 13 via the diode 15 and the changeover switch unit 16. The voltage measuring device 14 detects this voltage and uses the voltage information of the voltage measuring device 14 to determine that the coil 4 to be monitored is normal. On the other hand, when an abnormality such as a crack or a crack occurs in the coil 4 to be monitored, the voltage applied to the coil 4 increases due to an increase in the impedance of the coil 4. Further, when the wire is completely disconnected, the voltage applied to the coil 4 becomes very large. The voltage measuring device 14 detects this voltage and uses the voltage information of the voltage measuring device 14 to determine that the coil 4 to be monitored is abnormal.
Further, a plurality of coils 4 to be monitored are monitored for anomalies by switching circuits with the selector switch of the selector switch unit 16. Thereby, it is possible to monitor and detect abnormalities of a plurality of coils with one abnormality monitoring device, and further to identify the coil in which the abnormality is detected.
In this embodiment, in order to add or delete one monitoring target coil, it is sufficient to add or delete two cables. Therefore, the monitoring target coil can be easily added or deleted.
[0008]
FIG. 3 is an embodiment in which the changeover switch of the changeover switch unit 16 of each embodiment of FIGS. 1 and 2 is a manual changeover switch. In FIG. 3, push button switches 31 and 32 that open and close in conjunction with the input side and output side of the circuit to which the coil 4 to be monitored is connected are connected. In this way, the coil connected thereto can be switched while the pushbutton switch 31 is being pressed, and the coil connected thereto can be monitored while the pushbutton switch 32 is being pressed.
Here, as the switching method, in addition to a manual switching method using a push button switch or the like, any one or a combination of a switching method using a combination of a relay and a timer, a switching method using a digital signal and a program is used. There is a way.
[0009]
FIG. 4 shows an embodiment of circuit switching using a combination of relay and timer. In FIG. 4, relays 45, 46, 47 and timers 48, 49 are connected between a positive power supply bus 41 and a negative power supply bus 42 that are different from the bus connected to the coil 4 to be monitored.
First, when the input signal 43 is turned on, the timer 48 is excited, and at the same time, the relay 46 is excited, the a contact 46 'of the relay 46 is closed to form a self-holding circuit, and the coil 4 to be monitored is connected. The a-contact 33 of the relay 46 that closes the monitoring circuit that is being closed closes, and abnormality monitoring of the coil 4 is started. When the set time of the timer 48 elapses, the b contact 48 'of the timer 48 is opened and the relay 46 is de-energized, whereby the a contact 33 of the relay 46 is opened, and the abnormality monitoring of the coil 4 being monitored is performed. stop. At the same time, the a contact 48 "of the timer 48 is closed and the relay 47 is excited, whereby the a contact 47 'of the relay 47 is closed and a self-holding circuit is formed, and the coil 4 to be monitored is connected. The a contact 34 of the relay 47 that closes the monitoring circuit is closed and monitoring of the abnormality of the coil is started.When the timer 49 is excited at the time of the coil switching and the set time of this timer passes, Since the a contact 49 ″ is connected to the circuit to which the relay 46 and the timer 48 are connected, the coil 4 to be monitored is automatically switched as described above. When the turn-off signal 44 is turned on, the relay 45 is excited, the b contacts 45 ′ and 45 ″ of the relay 45 are opened, and the abnormality monitoring is stopped.
In this way, the abnormality monitoring coil can be switched using the relay timer.
[0010]
FIG. 5 shows a timing chart of the embodiment of FIGS. In the case of manual switching in FIG. 3, the coil is monitored only for the time the switch is pressed because of the switching by the pushbutton switch 31 or 32. Further, in the case of switching using the relay timer of FIG. 4, coil abnormality monitoring is started by an incoming signal and stopped by a turn-off signal, and during that period, automatic switching is performed at the set time of the timer.
[0011]
【The invention's effect】
As described above, according to the present invention, a plurality of coils are used in one abnormality monitoring device by using a change in the current value flowing through the monitoring circuit and a change in the voltage value applied to the monitoring target coil. Abnormality can be monitored, and addition and deletion of coils to be monitored can be easily performed.
In addition, by detecting and detecting an abnormality by switching a plurality of coils to be monitored with one abnormality monitoring device, it is possible to identify the coil in which the abnormality is detected.
[Brief description of the drawings]
FIG. 1 shows an embodiment of a coil abnormality monitoring device of the present invention. FIG. 2 shows another embodiment of the present invention. FIG. 3 shows an embodiment in which the changeover switch portion of the invention is a manual changeover switch. Embodiment of Circuit Switching Using Combination of Relay and Timer of Invention [FIG. 5] Timing Chart of Switching of the Present Invention [FIG. 6] Conventional Example [Explanation of Symbols]
DESCRIPTION OF SYMBOLS 1 ... Positive power source bus, 2 ... Negative power source bus, 3 ... Input command contact, 4 ... Coil to be monitored, 11 ... Constant voltage power source, 12 ... Current measuring device, 13 ... Constant current power source, 14 ... Voltage measuring device 15 ... Diode, 16 ... Changeover switch unit, 21 ... Abnormality monitoring device, 22 ... Abnormality monitoring device, 31,32 ... Push button switch, 33,34 ... Contact, 41 ... Positive power bus, 42 ... Negative power bus, 43 ... On signal, 44 ... Off signal, 45 ... Relay, 46 ... Relay, 47 ... Relay, 48 ... Timer, 49 ... Timer

Claims (2)

When monitoring abnormality of a plurality of coils to be monitored connected in parallel between power supply buses of the main circuit, a constant voltage power supply different from the main circuit, a diode for preventing inflow of reverse current, and a current measuring device And a plurality of changeover switches for switching the plurality of coils to be monitored, and a coil abnormality monitoring device for monitoring abnormality of the plurality of coils to be monitored based on current information detected by the current measuring device Because
Providing a circuit switching means for switching the changeover switch between a power supply bus different from the power supply bus of the main circuit;
The circuit switching means includes, for each of the plurality of changeover switches, a self-holding relay that operates the changeover switch, and a contact that forms a self-holding circuit that self-holds the relay when the relay is excited, A timer connected in series with the contact, connecting the timer contact and the self-holding relay in series, and connecting the timer in parallel with the series connected circuit;
When abnormality monitoring the first monitoring target coil, the first of the relay and the first of said timer excited, the excitation of the first relay at this time is set to a predetermined time set in the first timer , Abnormally monitoring the first monitored coil until the predetermined time has elapsed,
Subsequently, the abnormality monitoring of the second monitoring target coil is performed by connecting the second relay and the second timer connected in series on the condition that a predetermined time set by the first timer has elapsed. and closing the contacts of the first timer excites the second timer and the second relay, the excitation of the second relay in this case is a predetermined time set in the second timer, the predetermined The second monitoring target coil is abnormally monitored until time passes ,
Subsequently, the abnormality monitoring of the third and subsequent monitoring target coils is performed in the same manner,
A coil abnormality monitoring device characterized by automatically switching a plurality of coils to be monitored and monitoring the abnormality. When monitoring abnormality of a plurality of coils to be monitored connected in parallel between power supply buses of the main circuit, a constant current power supply different from the main circuit, a diode for preventing reverse current from flowing, and a voltage measuring device And a plurality of changeover switches for switching the plurality of coils to be monitored, and a coil abnormality monitoring device for monitoring abnormality of the plurality of coils to be monitored based on voltage information detected by the voltage measuring device. Because
Providing a circuit switching means for switching the changeover switch between a power supply bus different from the power supply bus of the main circuit;
The circuit switching means includes, for each of the plurality of changeover switches, a self-holding relay that operates the changeover switch, and a contact that forms a self-holding circuit that self-holds the relay when the relay is excited, A timer connected in series with the contact, connecting the timer contact and the self-holding relay in series, and connecting the timer in parallel with the series connected circuit;
When abnormality monitoring the first monitoring target coil, the first of the relay and the first of said timer excited, the excitation of the first relay at this time is set to a predetermined time set in the first timer , Abnormally monitoring the first monitored coil until the predetermined time has elapsed,
Subsequently, the abnormality monitoring of the second monitoring target coil is performed by connecting the second relay and the second timer connected in series on the condition that a predetermined time set by the first timer has elapsed. and closing the contacts of the first timer excites the second timer and the second relay, the excitation of the second relay in this case is a predetermined time set in the second timer, the predetermined The second monitoring target coil is abnormally monitored until time passes ,
Subsequently, the abnormality monitoring of the third and subsequent monitoring target coils is performed in the same manner,
A coil abnormality monitoring device characterized by automatically switching a plurality of coils to be monitored and monitoring the abnormality.

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