JP4138075B2 - Fuse blown detection protection device for high voltage equipment for temporary power transmission - Google Patents

Description

BACKGROUND OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuse blown detection protection device for a temporary power transmission high voltage device, and in particular, a fuse blown detection in a temporary power transmission high voltage device used to supply power by temporary power transmission when a power receiving facility of a high voltage consumer is newly installed or repaired. The present invention relates to a protective device.
[Prior art]
When power is supplied by temporary power transmission when a high-voltage customer's power receiving equipment is newly installed or refurbished, in order to prevent accidents from spreading to the power side in the event of an accident on the power receiving equipment side, power is supplied via a high-voltage device for temporary power transmission. Is called. This high-voltage device for temporary power transmission is roughly composed of a storage over-current and ground relay (SOG) switching unit and a switching unit with fuse. Specifically, it is configured to include a directional ground fault relay that detects a ground fault, a tripping high-voltage switch that shuts off the power source side and the load side, and a switch device. The switchgear includes a fuse that melts due to an overcurrent at the time of a short circuit accident and protects the load, and a mechanism that mechanically detects the blown fuse and opens the load side at once.
There are three types of accidents that can occur on the power receiving equipment side: ground fault, overcurrent accident, and accidents in which a ground fault and an overcurrent accident occur simultaneously. For these accidents, temporary power transmission high-voltage devices need to function effectively. The conventional high-voltage device for temporary power transmission opens the trip-type high-voltage switch if a ground fault occurs on the power receiving facility side during temporary power transmission, and mechanically shuts off the fuse in the event of a short-circuit accident. It is detected by the means and has a function of opening the three phases on the load side in a batch by the switchgear.
[Problems to be solved by the invention]
However, according to the conventional fuse blow detection protection device for temporary power transmission, when a short-circuit accident occurs, the fuse body is mechanically detected (for example, a mechanism is provided in the fuse body that causes a notch to pop out when a fuse blow occurs) In this configuration, the switch is driven to detect the pop-out of the notch and the load is released from the power source side, so that the structure becomes complicated and the size increases. The temporary power transmission high-voltage device is frequently used and frequently transported and moved. Therefore, when the temporary power transmission high-voltage device is increased in size, workability is deteriorated and a failure is likely to occur.
Accordingly, the object of the present invention is to electrically detect a fuse blown due to an overload / short-circuit accident and a mechanical shock during transportation or movement of the temporary power transmission high-voltage device to open the trip-type high-voltage switch. Another object of the present invention is to provide a protection device for detecting a blown fuse of a high-voltage device for temporary power transmission that can be reduced in size, weight, and high reliability with a simple configuration.
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides, as a first feature, a high voltage switch provided between the power supply side and the load side, which opens and closes the temporary power transmission line, and each phase on the load side of the high voltage switch. In the temporary power transmission high-voltage device used when performing temporary power transmission in construction such as new construction and renovation of high-voltage consumer power receiving equipment, on both sides of the plurality of fuses. An out-of-phase state is detected from the phase difference between the first and second voltage detection sensors provided to detect the voltage of each phase and the detected voltage between the first and second voltage detection sensors, and the first And a plurality of fuse blown detection circuits that determine whether the fuse is blown when a voltage of at least one phase of the voltages detected by the second voltage detection sensor is equal to or less than a predetermined value, and any of the plurality of fuse blown detection circuits Of the fuse Providing a blown fuse detection and protection apparatus of the temporary power transmission for high pressure and wherein said by providing a control means for opening the high-pressure switch, the when determining the cross-sectional.
In order to achieve the above object, the present invention has as a second feature, a high voltage switch provided between the power supply side and the load side, for opening and closing the temporary power transmission line, and a load side of the high voltage switch. A plurality of fuses inserted in each phase; a plurality of current transformers provided in each phase preceding the high-voltage switch; a zero-phase current transformer provided between the high-voltage switch and the fuse; In the temporary power transmission high-voltage device used when performing temporary power transmission in construction such as new construction and repair of high-voltage consumer power receiving equipment, the voltage of each phase is provided on both sides of the plurality of fuses. First and second voltage detection sensors for detection; a third voltage detection sensor provided on the power supply side of the high-voltage switch for detecting the voltage of each phase; the zero-phase current transformer; and the plurality of current transformers. The phase of the zero-phase current detected by the flow device and the third voltage detection sensor An out-of-phase state is detected from the phase difference between the detected voltage between the directional ground fault relay unit that detects a ground fault based on the phase of the zero-phase voltage and the first and second voltage detection sensors, and the first And a fuse blown detection circuit for determining whether the fuse is blown off when a voltage of at least one phase of the voltages detected by the second voltage detection sensor is equal to or less than a predetermined value, and the directional ground fault relay unit or the fuse blown detection And a control means for opening the high-voltage switch when an output signal is generated in the circuit. A fuse blown detection protection device for a high-voltage device for temporary power transmission is provided.
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a first embodiment of a fuse blown detection protection device for a temporary power transmission high voltage apparatus according to the present invention.
The fuse blown detection protection device 1 is connected to a trip type AC high voltage load switch (hereinafter referred to as “trip type high voltage switch”) 100 which is a component of a high voltage device for temporary power transmission. The fuse blown detection protection device 1 includes a phase A fuse blown detection circuit 10A, a phase B fuse blown detection circuit 10B and a phase C fuse blown which detect a phase difference and a voltage state based on a detection signal from the trip type high voltage switch 100. The detection circuit 10C, an OR circuit 20 (control means) that takes an OR logic of signals output from the three fuse blow detection circuits for each phase, and is turned on / off according to the output of the OR circuit 20 An LED (light emitting diode) 30 is provided. The output of the OR circuit 20 is applied to the trip coil 105 of the trip type high voltage switch 100 as a control command 40 (switch trip signal). The A-phase fuse blow detection circuit 10A, the B-phase fuse blow detection circuit 10B, and the C-phase fuse blow detection circuit 10C have the same configuration. FIG. 1 shows only the internal circuit for the A-phase fuse blow detection circuit 10A. .
The trip-type high voltage switch 100 corresponds to three phases (A phase, B phase, C phase). Between the power supply side terminal 101 and the load side terminal 102, the switch 103, fuses 104a, 104b are arranged in order from the power supply side. 104c are inserted and connected. The open / close unit 103 includes a trip coil 105 excited by an output from the fuse blown detection protection device 1, an armature 106a operated by the trip coil 105, and an operating member that opens and closes the open / close unit 103 in conjunction with the operation of the armature 106a. 106b is provided.
Voltage detection sensors 107a (PD1A), 107b (PD1B), and 107c (PD1C) are connected between the respective phases on the power source side of the fuses 104a, 104b, and 104c and the ground. Further, voltage detection sensors 108a (PD2A), 108b (PD2B), and 108c (PD2C) are connected between the respective phases on the load side of the fuses 104a, 104b, and 104c and the ground. The voltage detection sensors 107 a, 107 b, 107 c, 108 a, 108 b, and 108 c constitute a part of the fuse blown detection protection device 1, but the fuse blown detection protection device 1 from the trip-type high voltage switch 100 remains at a high voltage. Since the lead wire cannot be routed, it is provided in the trip type high voltage switch 100. Each of these voltage detection sensors is configured by connecting two capacitors in series, and detects a phase voltage divided by a capacitance ratio. Outputs of the voltage detection sensors 107a, 107b, and 107c are output to the signal line 109. Similarly, outputs of the voltage detection sensors 108a, 108b, and 108c are also output to the signal line 110.
Next, the configuration of the A-phase fuse blow detection circuit 10A will be described. An A / D converter 12a and a rectangular wave converter 13a are connected in parallel to the filter 11a connected to the signal line 109, and an A / D converter 12b and a rectangular wave converter are connected to the filter 11b connected to the signal line 110. 13b are connected in parallel. A phase comparison circuit 14 is connected to the rectangular wave converters 13a and 13b. A weighting circuit 15 is connected to the A / D converters 12a and 12b, and a NAND gate 16 is connected to the weighting circuit 15. An AND gate 17 is connected to the output of the NAND gate 16 and the output of the phase comparison circuit 14.
The filters 11a and 11b remove frequency components other than 50 Hz or 60 Hz in the signal lines 109 and 110. The rectangular wave converters 13a and 13b generate a rectangular wave from the sine wave signal. The phase comparison circuit 14 measures the phase difference from the time difference until the rise of the two rectangular waves output from the rectangular wave converters 13a and 13b. The weighting circuit 15 weights each of the digital values from the A / D converters 12a and 12b and converts them into ground voltage. Then, the converted value is compared with a preset reference value (for example, 1/2 of the ground voltage), and if the converted value exceeds the reference value, it is determined that the voltage appears in the detection unit of the voltage detection sensor. The NAND gate 16 becomes “L” level when the two outputs of the weighting circuit 15 are simultaneously “H” level, and outputs “H” level in other cases.
In the above configuration, operations in cases 1 to 5 will be described.
[Case 1]
When the open / close unit 103 is closed and the fuses 104a, 104b, and 104c are not blown out, a three-phase voltage having the same phase and no phase difference is detected between the voltage detection sensors 107a to 107c and 108a to 108c. Are output to the signal lines 109 and 110. As a result, the output signals of the A-phase fuse blow detection circuit 10A, the B-phase fuse blow detection circuit 10B, and the C-phase fuse blow detection circuit 10C are all at "L" level, and the output of the OR circuit 20 is at "L" level. Therefore, the LED 30 remains off and the control command 40 is not applied to the trip coil 105.
[Case 2]
When the open / close unit 103 is open (switch open) and the fuses 104a, 104b, 104c are not blown and no voltage is present on the load side, no output signal is generated from the filters 11a, 11b, and the AND gate 17 has an AND condition. Is not established, and no output voltage is generated in the A-phase fuse blow detection circuit 10A. Similarly, no output voltage is generated in the B-phase fuse blow detection circuit 10B and the C-phase fuse blow detection circuit 10C. For this reason, the OR circuit 20 does not hold the OR logic, the LED 30 remains off, and the open / close unit 103 remains open.
[Case 3]
When the switch 103 is open (switch is cut off), all of the fuses 104a, 104b, 104c are normal, and there is a voltage on the load side due to, for example, a generator connected to the load side Detection voltages are generated in the voltage detection sensors 108a, 108b, 108c and the voltage detection sensors 107a, 107b, 107c. In the A-phase fuse blow detection circuit 10A, the signal is output to each of the filters 11a and 11b. Therefore, the phase comparison circuit 14 cannot detect the phase difference, and its output becomes the “L” level. Further, since the A / D converters 12b and 12b also output signals to each other, there is no voltage difference, and the output of the NAND gate 16 whose two inputs are both at "H" level becomes "L" level. As a result, the AND gate 17 does not establish AND logic, and no output signal is generated from the A-phase fuse blow detection circuit 10A. Since the B-phase fuse blow detection circuit 10B and the C-phase fuse blow detection circuit 10C operate in exactly the same manner as the A-phase fuse blow detection circuit 10A, an output signal is output from the B-phase fuse blow detection circuit 10B and the C-phase fuse blow detection circuit 10C. Does not occur. For this reason, the OR circuit 20 has all three inputs at the “L” level, the output signal remains at the “L” level, the LED 30 remains off, and the control command 40 is not output to the trip coil 105.
[Case 4]
When the fuse 104a is blown under the state of the case 3, no detection voltage is generated in the PD 1A of the voltage detection sensor 107a, and detection voltages are generated in the PD 1B and the PD 1C. Further, a detection voltage is also generated in each of the voltage detection sensors 108a, 108b, and 108c. Therefore, the output signal of the B-phase fuse detection circuit 10B and the C-phase fuse detection circuit 10C remains at the “L” level as described in case 3, but the A-phase fuse detection circuit 10A operates differently. do. That is, no voltage is generated in the rectangular wave converter 13a, and a voltage is generated only in the rectangular wave converter 13b. Therefore, the phase comparison circuit 14 generates an "H" level output signal.
On the other hand, no output is generated in the A / D converter 12a, and an output is generated only in the A / D converter 12b. As a result, in the weighting circuit 15, an output voltage is generated at one output terminal, and no output voltage is generated at the other output terminal. For this reason, one of the inputs of the NAND gate 16 becomes “H” level and the other becomes “L” level, and the output of the NAND gate 16 becomes “H” level. Since the two inputs of the AND gate 17 are both at the “H” level, the output becomes the “H” level. In the OR circuit 20, the output of the A-phase fuse blow detection circuit 10A is “H” level, the output of the B-phase fuse blow detection circuit 10B is “L” level, and the output of the C-phase fuse blow detection circuit 10C is “L” level. Therefore, the OR logic is established, and the output becomes the “H” level. Accordingly, the LED 30 is turned on to warn of “fuse blown (fuse cut off)” and a control command 40 is output. However, in this state, since the opening / closing part 103 has already been opened, that state is maintained. Although the fuse 104a has been described, the operation is the same even when the other fuses 104b and 104c are cut off.
In case 3, when all of the fuses 104a, 104b, 104c are blown, the outputs of the A-phase fuse blow detection circuit 10A, the B-phase fuse blow detection circuit 10B, and the C-phase fuse blow detection circuit 10C are all at the “H” level. Thus, the OR circuit 20 operates, the LED 30 is turned on, and the control command 40 is output. As described above, since the final output is obtained via the OR circuit 20, if one fuse is blown, the same operation is performed regardless of whether two fuses are blown or three.
[Case 5]
When one of the fuses 104a, 104b, and 104c, for example, the fuse 104a is blown, with the open / close unit 103 closed, a detection voltage is generated in each of the voltage detection sensors 107a, 107b, 107c, 108b, and 108c. The detection voltage is not generated in the voltage detection sensor 108a. Therefore, an output is generated in the rectangular wave converter 13a and no output is generated in the rectangular wave converter 13b. Therefore, the output of the phase comparison circuit 14 is at the “H” level. Further, since an output is generated in the A / D converter 12a and no output is generated in the A / D converter 12b, one of the inputs of the NAND gate 16 becomes "H" level and the other becomes "L" level. Becomes “H” level. Since both the NAND gate 16 and the phase comparison circuit 14 output “H” level, the output of the AND gate 17 becomes “H” level. At this time, the outputs of the B-phase fuse blow detection circuit 10B and the C-phase fuse blow detection circuit 10C are both at the “L” level, but since the output of the AND gate 17 is at the “H” level, the OR circuit 20 has the OR logic. The output is established and the output becomes “H” level. Accordingly, the LED 30 is turned on to warn of “fuse blown”. At the same time, as a result of the output of the control command 40, the trip coil 105 is energized, and the trip type high voltage switch 100 is tripped (opening / closing part 103 is opened).
Next, the reason why the AND gate 17 takes the AND condition of the phase difference and the presence / absence of voltage as described above will be described. When the open / close unit 103 is closed, a sneak voltage is generated depending on the load state, and even if the fuse is blown, it is conceivable that the detected voltage becomes equal to or higher than a normal voltage value. Therefore, if it is determined that the fuse is blown based only on the presence or absence of the detection voltage, it may be determined that the fuse is blown but the fuse is actually blown. When the fuse is blown, the phase of the sneak voltage of the phase becomes a phase value obtained by synthesizing the other phases, so that the phase difference from the opposite end where the voltage is generated is 180 ° ± 70 °. Therefore, in the present invention, the phase difference is detected, and if the phase of the sneak voltage is ± 45 ° or more, the phase difference is detected, and when the two conditions of voltage detection are satisfied simultaneously with the detection of the phase difference, the blown fuse is determined. .
FIG. 2 shows a second embodiment of a fuse blown detection protection apparatus according to the present invention. In FIG. 2, the same reference numerals are used for those having the same or the same functions as the members shown in FIG. The feature of this embodiment is that an SOG function is provided, delay function priority processing is performed at the time of a short-circuit failure, and fuse blown trip control is not performed during storage trip storage. That is, the short circuit current is not interrupted.
In order to have the SOG function, the trip type high voltage switch 100 includes, in addition to the configuration of FIG. 1, voltage detection sensors 111a (PD3A), 111b (PD3B), 111c (PD3C), a current transformer (CT) 112a, 112b and 112c and a zero-phase current transformer (ZCT) 113 are provided. The voltage detection sensors 111a, 111b, and 111c are provided between the power supply side terminal 101 and the ground. Current transformers (CT) 112a, 112b, and 112c are attached to the phases A, B, and C between the power supply side terminal 101 and the switching unit 103, and the zero-phase current transformer (ZCT) 113 includes the switching unit 103 and the fuse 104. It is attached to each phase A, B, C. Like the other voltage detection sensors, the voltage detection sensors 111a, 111b, and 111c are part of the fuse blown detection protection device 1, but the fuse blown detection protection from the trip-type high voltage switch 100 remains at a high voltage. Since the lead wire cannot be routed to the device 1, it is provided in the trip type high voltage switch 100.
Further, the fuse blown detection protection device 1 includes a fuse blown detection circuit 50 including three circuits of the fuse blown detection circuits 10A, 10B, and 10C shown in FIG. 1 and the LED 30, as well as a directional ground fault relay unit 60, A phase detection circuit 70, an OR gate 80 (control means), and an LED 90 are provided. The output of voltage detection sensors 111a, 111b, 111c, current transformers 112a, 112b, 112c, and zero-phase current transformer 113 is input to directional ground fault relay unit 60.
In the configuration of FIG. 2, the operation of the fuse blow detection circuit 50 is as described in the A phase fuse blow detection circuit 10A, the B phase fuse blow detection circuit 10B, and the C phase fuse blow detection circuit 10C in FIG. A duplicate description is omitted.
When an overcurrent accident on the load side is detected by the current transformers 112a, 112b, and 112c, the occurrence of the overcurrent accident is stored in storage means (not shown), and the LED 30 is turned on. At this time, the circuit breaker (not shown) on the power supply side operates to make the high-voltage distribution line blackout. When the control power supply is lost due to a power failure in the high-voltage distribution line, for example, after a lapse of 0.5 seconds or more, the trip-type high-voltage switch 100 is automatically opened.
In the event of a ground fault, based on the phase of the zero-phase current detected by the zero-phase current transformer 113 and the current transformers 112a, 112b, 112c and the phase of the zero-phase voltage detected by the voltage detection sensors 107a, 107b, 107c. The directional ground fault relay unit 60 determines the direction of the ground fault current. If it is determined that a load-side ground fault has occurred, a “ground fault” detection signal (“H” level voltage) is output to the OR gate 80. The OR gate 80 sets the output to the “H” level, applies the control command 40 to the trip coil 105, and opens the trip type high voltage switch 100.
The phase detection circuit 70 compares the detection voltages of the voltage detection sensors 111a, 111b, and 111c with the detection voltages of the voltage detection sensors 108a, 108b, and 108c between the same phases, and from the phase difference, the phase difference between the power supply side and the load side is different. Is detected, the LED 90 is lit to warn that it is in the “different phase” state.
In the configuration of FIG. 2, as described above, since it has the SOG function, when a ground fault and an overcurrent accident overlap, the operation of the overcurrent relay has priority. Therefore, after the operation of the circuit breaker, the trip type high voltage switch 100 is opened after 0.5 seconds or more. Further, when storing the stored trip, the fuse blown trip control is not performed, whereby the short-circuit current is not cut off. For this reason, the fuse blow detection time is set longer than the ground fault detection time, so that the ground fault detection process can be surely prioritized over the fuse blow detection process.
In each of the above embodiments, one LED 30 is connected to the OR circuit 20, and it is not known which of the fuse blow detection circuits 10A, 10B, and 10C has caused the fuse blow. However, the fuse blow detection circuit 10A, If it is configured to connect to each of the output terminals 10B and 10C, it is possible to know in which phase the fuse has blown.
In the above description, the trip-type high voltage switch has been described as an example, but the present invention is not limited to this type. Further, the present invention can be applied not only to three phases but also to other single phases.
【The invention's effect】
As described above, according to the fuse blown detection protection device of the temporary power transmission high voltage device of the present invention, the voltage detection sensor detects the out-of-phase state from the phase difference of the phase voltage detected from both sides of the fuse, and the voltage detection sensor A plurality of fuse blow detection circuits that determine whether a fuse is blown when the voltage detected in step 1 is equal to or lower than a predetermined value, and a control that opens the high-voltage switch when any of the plurality of fuse blow detection circuits determines that the fuse is blown Because it has a configuration with means, it can electrically detect a blown fuse due to a short circuit accident to open the high-voltage switch, and achieve a small size, light weight and high reliability of the temporary power transmission high-voltage device with a simple configuration. can do.
Furthermore, a directional ground fault relay unit that detects the time of a ground fault based on the phase of the zero phase current and the phase of the zero phase voltage, and determines that the fuse is blown when the voltage detected by the voltage detection sensor is below a predetermined value. By comprising a plurality of fuse blown detection circuits and a control means for opening the high-voltage switch when an output signal is generated in either the directional ground fault relay unit or the fuse blown detection circuit Priority can be given to the delay function at the time of a short circuit failure, and the safety of the system can be improved. Further, it is possible to prevent the fuse blown trip control from being performed during the stored energy trip.
[Brief description of the drawings]
FIG. 1 is a circuit diagram showing a first embodiment of a fuse blown detection protection device for a temporary power transmission high voltage device according to the present invention;
FIG. 2 is a circuit diagram showing a second embodiment of a fuse blown detection protection device according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Fuse blow detection protection apparatus 10A A phase fuse blow detection circuit 10B B phase fuse blow detection circuit 10C C phase fuse blow detection circuit 11a, 11b Filter 12a, 12b A / D converter 13a, 13b Rectangular wave converter 14 Phase comparison circuit 15 Weighting circuit 16 NAND gate 17 AND gate 20, 80 OR circuit 30 LED
50 Fuse blown detection circuit 60 Directional ground fault relay unit 100 Trip type high voltage switch 103 Open / close unit 104a, 104b, 104c Fuse 105 Trip coil 107a, 107b, 107c Voltage detection sensor 108a, 108b, 108c Voltage detection sensor 111a, 111b , 111c Voltage detection sensors 112a, 112b, 112c Current transformer 113 Zero phase current transformer

Claims (4)

A high-voltage switch provided between the power supply side and the load side, which opens and closes the temporary power transmission line, and a plurality of fuses inserted in each phase on the load side of the high-voltage switch. In temporary power transmission high-voltage equipment used for temporary power transmission in construction of new facilities and repairs, etc.
First and second voltage detection sensors provided on both sides of the plurality of fuses for detecting the voltage of each phase;
An out-of-phase state is detected from a phase difference between detection voltages between the first and second voltage detection sensors, and at least one phase voltage detected by the first and second voltage detection sensors is equal to or less than a predetermined value. A plurality of fuse blown detection circuits that determine whether the fuse is blown off, and
Control means for opening the high-voltage switch when any of the plurality of fuse blown detection circuits determines that the fuse is blown;
A fuse blown detection protection device for a temporary power transmission high voltage device. 2. The fuse blown detection protection device of the high voltage device for temporary power transmission according to claim 1, wherein the fuse blown detection circuit determines whether or not the voltage is equal to or less than the predetermined value with reference to 1/2 of the ground voltage. . 2. The fuse blown detection circuit according to claim 1, wherein the detection of the different phase is performed when a phase difference between detection voltages between the first and second voltage detection sensors is ± 45 ° or more. Fuse blown detection protection device for high voltage equipment for temporary power transmission. A high-voltage switch provided between the power supply side and the load side, for opening and closing the temporary power transmission line, a plurality of fuses inserted in each phase on the load side of the high-voltage switch, and each phase preceding the high-voltage switch And a zero-phase current transformer provided between the high-voltage switch and the fuse. In the high voltage device for temporary power transmission used when performing power transmission, first and second voltage detection sensors that are provided on both sides of the plurality of fuses and detect the voltage of each phase;
A third voltage detection sensor provided on the power supply side of the high-voltage switch for detecting the voltage of each phase;
Directional ground fault relay for detecting a ground fault based on the phase of the zero phase current detected by the zero phase current transformer and the plurality of current transformers and the phase of the zero phase voltage detected by the third voltage detection sensor And
An out-of-phase state is detected from a phase difference between detection voltages between the first and second voltage detection sensors, and at least one phase voltage detected by the first and second voltage detection sensors is equal to or less than a predetermined value. A fuse blown detection circuit that determines the interruption of the fuse when it is,
Control means for opening the high-voltage switch when an output signal is generated in the directional ground fault relay section or the fuse blown detection circuit;
A fuse blown detection protection device for a temporary power transmission high voltage device.

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