JP3564823B2 - Switchgear - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a switchgear mainly used for divided opening and closing of an extra-high voltage and a high voltage distribution system.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as shown in FIG. 2, a switching device of this type of distribution system is formed by a switch 1 inserted into the distribution system, a control device 2 for controlling the opening and closing thereof, and a control transformer 3.
[0003]
The single-phase control transformer 3 has two primary phase lines 4a, 4b and 4c of the A, B and C phases of the distribution line 4, for example, the A and C phase lines 4a. , it is connected from the switch 1 on the upstream side to 4c, stepping down the input power iN of the voltage _{V 1} of the primary side, for example, about 100 V.
[0004]
Further, in the case of FIG. 2, the control power supply is DC, and the switch 1 is turned on by the DC control power supply. Therefore, the secondary output OUT of the control transformer 3 is supplied to the rectifier 5 of the control device 2. The rectifier 5 converts the secondary output OUT into a DC control power supply.
[0005]
Further, a power supply monitoring relay 6 is provided on the input side of the rectifier 5, and the relay 6 monitors the presence or absence of a control power supply from the secondary output OUT.
[0006]
That is, when the power supply monitoring relay 6 becomes higher than the reference voltage of the set power supply monitoring voltage V ₂ of the secondary output OUT is the operating voltage of the power source monitoring relays 6, the operation (make) to inverted from the open position to the closed position and generates a contact signal of "1" indicating the Available power supply, when the voltage V ₂ of the secondary side output OUT at a power failure or the like of the distribution line 4 is sufficiently lower than the reference voltage of the power source monitoring, open become inoperative The state is maintained, and the contact signal becomes a signal of “0” indicating no power supply.
[0007]
The contact signal of the power monitoring relay 6 is supplied to a discrimination control unit 7 formed by a microcomputer or the like. In response to a contact signal of the switching state of the switch 1 given from the auxiliary contact 8 of the switch 1, the switching state of the main circuit contacts 9a, 9b, 9c inserted in series with the respective phase lines 4a, 4b, 4c, ie, the switch 1 The open / close state of is determined.
[0008]
Then, in the case of automatic power-on, when the contact signal of the power supply monitoring relay 6 changes from non-powered to powered-on based on power restoration from the upstream side of the distribution line 4, the discrimination control unit 7 executes Then, it is confirmed that there is a control power source, and the closing relay contacts 11a and 11b provided between the rectifier 5 and the closing coil 10 of the switch 1 are closed at a predetermined time.
[0009]
By this closing, a DC control power of the rectifier 5 is supplied to the input coil 10, and the coil 10 is energized to close the main circuit contacts 9a, 9b, 9c, and the switch 1 is automatically turned on for a predetermined time period. To close.
[0010]
Then, the auxiliary contact 8 is closed in conjunction with the closing of the main circuit contacts 9a, 9b, 9c, and the completion of closing of the switch 1 is notified to the discrimination control unit 7, and the discrimination control unit 7 performs the closing control by this notification. Are completed, and the closing relay contacts 11a and 11b are opened to stop the energization of the closing coil 10.
[0011]
The switch 1 is mechanically held in a closed state until a trip coil (not shown) is energized.
[0012]
[Problems to be solved by the invention]
In the case of the conventional switchgear shown in FIG. 2, the reference voltage for power supply monitoring is determined by the operating voltage of the power supply monitoring relay 6, and the reference voltage for power supply monitoring is set to an optimum voltage that guarantees the operation (energization) of the closing coil 10. In particular, when a general-purpose relay whose operating voltage is standardized is used for the power supply monitoring relay 6 in order to reduce costs and the like, the voltage V ₂ of the secondary output OUT is reduced by the operation of the power supply monitoring relay 6. Even when the voltage is higher than the voltage, the voltage applied to the closing coil 10 may be insufficient.
[0013]
That is, the power supply monitoring relay -6 formed by a general-purpose relays, typically, the operating voltage is about half of the normal value of the voltage V ₂ of the secondary output OUT (rated value), this case, the control transformer some abnormality of the failure or the like 3 is generated, the voltage V ₂ of the secondary output OUT drops below a predetermined amount lower voltage than the normal value, but the voltage V ₂ is the operating voltage range of the voltage monitoring relays 6, A situation occurs in which the voltage applied to the closing coil 10 is insufficient.
[0014]
If the voltage applied to the closing coil 10 is insufficient, sufficient electrical energy is not supplied to the closing coil 10 even when the closing control is performed, and the switch 1 enters a so-called incomplete closing state. Insufficient capacity of the open / close contacts causes problems such as the fusion of the contacts, thus deteriorating the reliability.
[0015]
SUMMARY OF THE INVENTION It is an object of the present invention to improve the reliability by detecting an output abnormality (output decrease) of a control transformer, notifying the occurrence of an abnormality by prohibiting the opening of a switch when the abnormality occurs.
[0016]
[Means for Solving the Problems]
In order to achieve the above object, a switchgear according to claim 1 of the present application detects a two-phase line voltage of a distribution line applied to a primary side of a control transformer, and detects the line voltage. A voltage detecting unit for forming a reference voltage for monitoring the transformer, wherein the voltage is adjusted to be equal to the voltage of the secondary-side output of the control transformer in a normal state;
An error calculator for calculating a difference between a reference voltage for transformer monitoring and a voltage of the secondary output;
When the voltage of the secondary side output is equal to or less than a predetermined threshold value lower than the reference voltage for monitoring the transformer based on the calculation result of the error calculation unit, the output abnormality of the control transformer is detected and the closing control of the discrimination control unit is performed. A transformer abnormality detecting means for inhibiting and closing the closing relay contact, and
Abnormality notification means for notifying an output abnormality of the control transformer based on the detection of the transformer abnormality detection means.
[0017]
Accordingly, the voltage detecting unit adjusts the two-phase line voltage of the distribution line to form a reference voltage for monitoring the transformer equal to the voltage (rated voltage) of the secondary output of the control transformer in a normal state. Thus, the difference between the reference voltage for monitoring the transformer and the voltage of the secondary output is calculated.
[0018]
Then, when an output abnormality of the control transformer occurs and the voltage of the secondary output thereof becomes equal to or lower than a predetermined threshold value lower than the reference voltage of the transformer monitoring, and the applied voltage of the closing coil becomes insufficient, the transformer abnormality occurs. The detecting means detects the output abnormality of the control transformer from the calculation result of the error calculating section, inhibits the closing control of the discriminating control section, holds the closing relay contact open, opens the energizing path of the closing coil and opens the switch of the switch. Prohibit input.
[0019]
Further, based on the detection of the transformer abnormality detecting means, the abnormality notifying means notifies an output abnormality of the control transformer.
Therefore, when an output abnormality of the control transformer occurs, the closing of the switch is prohibited to prevent occurrence of an incompletely closed state, and an output abnormality of the control transformer is notified, thereby improving reliability.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
One embodiment of the present invention will be described with reference to FIG.
In FIG. 1 showing the entire configuration, the same reference numerals as those in FIG. 2 denote the same components, and the switchgear of FIG. 1 differs from the conventional device of FIG. 2 in the following points (i) to (iv).
[0021]
(I) switch 1 point having a capacitor dividing system type voltage detecting unit 12 that forms a reference voltage V ₃ of the transformer monitoring.
[0022]
(Ii) the control device 2 that is provided with error computing section 13 for calculating a difference between the voltage V ₂ between the reference voltage V ₃ of the transformer monitoring the secondary side output OUT to.
[0023]
(Iii) The control device 2 is provided with a discrimination control unit 14 having a configuration obtained by adding a transformer abnormality detection means to the discrimination control unit 7 instead of the conventional discrimination control unit 7.
[0024]
(Iv) A point that an abnormality notification unit 15 connected to the discrimination control unit 14 is provided in the control device 2.
[0025]
The voltage detection unit 12 divides the voltage of the A phase of the distribution line 4 by the capacitors 16 and 17 provided in series between the phase line 4a and the ground, and converts the voltage of the C phase of the distribution line 4 to the phase line 4c. The voltage is divided by capacitors 18 and 19 provided in series between the capacitor and the ground.
[0026]
Further, the voltage between the terminals of the capacitors 16 and 18 on the ground side is subtracted by the subtractor 20 to detect the same A- and C-phase line voltage as the primary-side input of the control transformer 3, and the line voltage is controlled. voltage V ₂ of the secondary output OUT during normal use transformer _3, i.e., to form the reference voltage V ₃ of the transformer monitoring adjusted to be equal to the voltage of the normal value of the voltage V ₂ (rated value).
The size of the reference voltage V ₃ of the transformer monitoring is set by adjusting the voltage dividing ratio by the condenser 16 to 19.
[0027]
The reason why the capacitor voltage dividing method of dividing the voltage by the capacitors 16 to 19 is adopted is that there is an advantage that it can be formed smaller than when a transformer is used. during voltage of it may form a reference voltage V ₃ by adjusting the is a matter of course.
[0028]
Then, by supplying the voltage V ₂ of the secondary output OUT of the reference voltage V ₃ and the control transformer 3 of the transformer monitoring error calculation unit 13 of the subtracter arrangement, both the voltages V ₃ by the error calculator _13, V ₂ of the difference a _(V 3 -V ₂₎ is calculated in real time, and supplies the result of the calculation to the determination control unit 14.
[0029]
The discrimination control unit 14 monitors the calculation result of the error calculation unit 13 by a transformer abnormality detection unit formed by software of a microcomputer, for example, and an output abnormality of the control transformer 3 occurs. V ₂ is below a lower predetermined threshold from the reference voltage V ₃ of the transformer monitoring, the applied voltage of the closing coil 10 is situation where insufficient, based on the reduction of the calculation result of the error calculator 13, the control transformer 3 Output error is detected.
[0030]
Further, as an abnormality process based on the detection of the output abnormality, the transformer abnormality detecting means prohibits the closing control of the discrimination control unit 14 based on the contact signal of the power monitoring relay 6 with the power supply, and keeps the closing relay contacts 11a and 11b open. I do.
[0031]
Due to this open holding, the control power of the rectifier 5 is not supplied to the closing coil 10 of the switch 1, and the switch 1 is prohibited from being turned on and is held open. This prevents occurrence of troubles such as fusion of contacts.
[0032]
When the transformer abnormality detecting means detects an output abnormality of the control transformer 3, it supplies a notification command to the abnormality notifying means 15, and based on this supply, the abnormality notifying means 15 turns on a lamp or displays characters and graphics. The failure of the control transformer 3 is displayed to notify the output abnormality.
[0033]
Therefore, even if a general-purpose relay is used as the power supply monitoring relay 6, the conventional problem based on the output abnormality of the control transformer 3 does not occur, and the occurrence of the output abnormality can be easily known. The reliability is remarkably improved, and as a result, the reliability of the distribution system is improved, and a remarkable effect is obtained particularly when the reliability of the control transformer 3 is not high.
[0034]
The transformer abnormality detecting means and the like of the discrimination control unit 14 may be formed by hardware such as a logic circuit instead of being formed by software of a computer.
Further, a means for communicating the occurrence of an output abnormality of the control transformer 3 to a remote monitoring station or the like and notifying the occurrence of the abnormality may be provided as the abnormality notification means.
[0035]
Further, in the case of FIG. 1, the control power supply is DC, but the control power supply is AC. For example, the present invention is also applicable to a case where the rectifier 5 is omitted and the secondary output OUT of the control transformer 3 is supplied to the input coil 10. Of course you can.
[0036]
【The invention's effect】
The present invention has the effects described below.
Output abnormality occurs in the control transformer 3 becomes below its secondary output voltage V ₂ reaches a predetermined lower reference voltage V ₃ of the transformer monitoring of the voltage detection unit 12 threshold voltage applied closing coil 10 Is insufficient, the transformer abnormality detecting means detects the output abnormality of the control transformer 3 from the calculation result of the error calculation unit 13, inhibits the making control of the discrimination control unit 14, and opens the making relay contacts 11a and 11b. Then, the energizing path of the closing coil 10 is opened to prohibit closing of the switch 1.
[0037]
Further, based on the detection of the transformer abnormality detecting means, the abnormality notifying means 15 notifies the output abnormality of the control transformer 3.
Therefore, when an output abnormality of the control transformer 3 occurs, the closing of the switch 1 can be prohibited to prevent the occurrence of an incompletely closed state, and the output abnormality of the control transformer 3 can be notified. And the reliability can be significantly improved.
[Brief description of the drawings]
FIG. 1 is a circuit block diagram of one embodiment of the present invention.
FIG. 2 is a circuit block diagram of a conventional device.
[Explanation of symbols]
1 switch 3 control transformer 4 distribution line 6 power monitoring relay 10 closing coil 11a, 11b is turned relay contact 12 voltage detection unit 13 of the error calculating unit 14 determines the control unit 15 abnormality notification means _{V 2} control transformer secondary output the reference voltage of the voltage V ₃ transformer monitoring

Claims (1)

A DC or AC control power source is formed by a secondary output of a control transformer whose primary side is connected to two phases of a distribution line,
The voltage of the secondary output is monitored by a power monitoring relay to detect the presence or absence of the control power,
When the voltage of the secondary output is equal to or higher than a reference voltage for power monitoring determined by an operating voltage of the power monitoring relay, the power monitoring relay supplies a contact signal of a power supply to the discrimination control unit from the power monitoring relay,
By the closing control of the discrimination control unit, a closing relay contact between the control power supply and a closing coil of a switch is closed under a condition of input of the contact signal of the power supply, and the closing coil is energized to open and close the switching relay. In the switchgear that puts the container,
A voltage detection unit that detects a two-phase line voltage of the distribution line and forms a reference voltage for transformer monitoring in which the line voltage is adjusted to be equal to the voltage of the secondary output in a normal state;
An error calculation unit that calculates a difference between the reference voltage for monitoring the transformer and the voltage of the secondary output,
When the voltage of the secondary output is equal to or less than a predetermined threshold value lower than the reference voltage for monitoring the transformer based on the calculation result of the error calculation unit, an output abnormality of the control transformer is detected. Transformer abnormality detecting means for inhibiting the closing control and opening and holding the closing relay contact;
An opening / closing device comprising: an abnormality notification unit that notifies an output abnormality of the control transformer based on the detection of the transformer abnormality detection unit.

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