JP3649365B2 - Unipolar intermittent arc optical ground fault test equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a unipolar intermittent arc light ground fault test apparatus for artificially generating a unipolar intermittent arc light ground fault in a simulated distribution line and performing a ground fault accident test of various power receiving equipment.
[0002]
[Prior art]
Conventionally, in high-voltage power receiving equipment installed at the demarcation point between electric power companies and customers, it has been recommended to use equipment with a ground fault detection function in order to prevent spillovers based on the occurrence of accidents within customers. .
FIG. 4 shows an example of such a case, 51 is a lead-in switch, 52 is an overcurrent lock type high-pressure air switch (GRS with PAS), 53 is a cable, 60 is a high-voltage power receiving facility, and 61 is a voltage transformer. A current transformer (VCT), 62 is a circuit breaker, 63 is a capacitor, and 64 is a transformer. In this example, the PAS 52 with GR has a ground fault detection function. When a ground fault occurs on the customer side, the PAS 52 with GR is opened before the circuit breaker of the power company's substation. It is possible to prevent the power outage of other customers.
By the way, the ground fault includes an intermittent arc light ground fault in which a ground fault current flows intermittently. Furthermore, in the case of a ground fault occurring in the ungrounded distribution line, a half-wave rectified waveform with only one of positive and negative zero-phase current is generated due to the core saturation of the grounded instrument transformer (EVT), In addition, there may be a sawtooth waveform. As described above, when the zero-phase voltage and the zero-phase current have complicated waveforms, it becomes more difficult to detect the ground fault. Moreover, even with these difficult-to-detect zero-phase voltages and zero-phase currents, the above-mentioned equipment with a ground fault detection function is required to have a function of reliably detecting a ground fault and accurately identifying the position of the fault point. . For this reason, it is necessary to verify the performance of accident detection devices and accident detection systems installed on distribution lines assuming actual use. Therefore, in the past, these test equipments were connected to a simulated distribution line, and various ground faults were artificially generated for testing. By the way, conventionally, when attempting to artificially reproduce the intermittent arc light ground fault phenomenon for the ground fault test, it has been generated using a cable, insulator, gap or the like at the ground fault point.
[0003]
[Problems to be solved by the invention]
However, the actual situation is that these intermittent arc light ground faults, etc. have many elements due to chance, such as the frequency of occurrence depending on the line constant, and the reproducibility of the occurrence is low. Therefore, when installing a distribution line accident detection device or system on a simulated distribution line and conducting a verification test on an intermittent arc light ground fault, it is difficult to reach a ground fault or immediately cause a ground fault. It is extremely poor in performance and needs to be repeated many times to accumulate data, and a great deal of time and labor has been spent on its implementation. In addition, the “single-sided insulator arc” method, in which diodes are connected in series in multiple stages between the enameled wire and the power supply, and only half the AC voltage is applied to the insulator, requires a lot of manpower. There was a problem that the danger increased.
[0004]
[Means for Solving the Problems]
In order to solve the above problems, the invention of claim 1 is directed to a primary side distribution line connected to a primary side of a device under test, and a power source that applies a voltage imitating a substation connected to the primary side distribution line. Circuit, simulated distribution line capacity connected between primary side distribution line and ground, secondary side distribution line connected to secondary side of device under test, connected between secondary side distribution line and ground It is equipped with a simulated distribution line capacity, a ground fault line connecting the secondary side distribution line and the ground, and a rectifying element, a switch and an accident point generating equipment connected in series to the ground fault line. To do.
Here, it is preferable to use a high-pressure pin insulator having a crack as the accident point occurrence equipment.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a configuration of an embodiment of the present invention. As shown in the figure, this apparatus is a power supply circuit that simulates a power company substation and supplies power, and is connected to the simulated substation 1 and the primary side of the EUT 2. A primary distribution line 3 connected to the primary distribution line 3, a simulated distribution line capacity 4 connected between the primary distribution line 3 and the ground, a secondary distribution line 5 connected to the secondary side of the EUT 2, The simulated distribution line capacity 6 connected between the secondary distribution line 5 and the ground, the ground fault line 7 formed between the R phase of the secondary distribution line 5 and the ground, and the ground fault line 7 are connected. A rectifier element 8, a high-voltage pin insulator 9 having a crack connected to the ground fault line 7 as an accident point, and a fault point switching switch connected to the ground fault line 7. 10.
[0006]
Conventionally, when a ground fault is generated in a distribution line via a cracked high-voltage pin insulator or the like, one-side discharge is randomly generated, and the rate of one-side discharge during the ground fault period can be controlled. In contrast to this, in this embodiment, a diode is connected in series with the part of the accident point so that a discharge phenomenon occurs only on one side. That is, by closing the switch 10 on the ground fault line 7, a ground fault current flows only in the direction from the R phase of the secondary distribution line 5 to the ground through the diode 8, and the unipolar intermittent arc optical ground fault is ensured. Can be reproduced. In this state, the ground fault detection performance of the connected EUT 2 can be inspected.
[0007]
Moreover, in this embodiment, it is also possible to perform a test by reversing the direction of the ground fault current by reversing the connection direction of the diode 8. Furthermore, if a semiconductor switch (GTO) is used instead of the diode 8, the duration of unipolar discharge can be controlled. Similarly, for the switch 10, it is also possible to install a control device (not shown) and execute an opening / closing operation at a preset opening / closing timing.
[0008]
FIG. 2 is a graph showing the relationship between the bank capacitance of the simulated distribution line and the one-side discharge occurrence rate, and it has been confirmed that the one-side discharge occurrence rate changes in relation to the bank capacitance. In the figure, the smaller the bank capacitance, the higher the occurrence rate, and it is shown that when the bank capacitance per phase is 0.7 μF or less, almost one-sided discharge occurs.
[0009]
FIG. 3 is a circuit diagram showing a connection example in the case of performing a ground fault detection performance test of a PAS with GR installed on a utility pole in a customer premises as a test equipment. The primary side distribution line 3 in FIG. 1 is connected to the power supply side on the left side of the switch body 521 in the figure, and the secondary side distribution line 5 is also connected to the right load side. Further, each terminal at the lower part of the main body is connected to the control device 523 via the 11-core cable 522. By generating a unipolar intermittent arc light ground fault on the load side in this state, the ground fault test of the switch body 521 is performed, and the ground fault detection function of the switch body 521 is determined.
The configuration of the switch body 521 is well known and will not be described in detail. In the figure, ZCT is a zero-phase current transformer, S is an interlocking switch, TC is a tripping coil, CT is a current transformer, and ZPD is zero. Phase voltage detector.
[0010]
As described above, in the present invention, it is possible to reliably generate a unipolar intermittent arc light ground fault, thereby enabling a reproducible and quantitative artificial unipolar intermittent arc light ground fault test to be performed. This significantly reduces the time and effort required to implement it, and also improves test safety.
[0011]
【The invention's effect】
As described above, according to the present invention, the rectifier, the switch, and the accident point occurrence equipment are connected to the ground fault line connected to the secondary distribution line of the device under test, and the switch is closed. Therefore, it is possible to reliably generate a single-pole intermittent arc light ground fault and to perform a ground fault test with excellent reproducibility and safety.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of an exemplary embodiment of the present invention.
2 is a graph showing the relationship between the bank capacitance and the one-side discharge occurrence rate in the embodiment of FIG.
FIG. 3 is a circuit diagram showing a specific connection example in the embodiment of FIG. 1;
FIG. 4 is a diagram illustrating an installation example of a high-voltage power receiving facility installed at a demarcation point between a power company and a customer.
[Explanation of symbols]
1 Simulated substation 2 EUT 3 Primary distribution line 4 Simulated distribution line capacity 5 Secondary distribution line 6 Simulated distribution line capacity 7 Ground fault line 8 Diode 9 High voltage pin insulator 10 Switch

Claims (2)

A primary distribution line connected to the primary side of the device under test;
A power circuit connected to the primary distribution line and applying a voltage simulating a substation;
A simulated distribution line capacity connected between the primary distribution line and the ground;
A secondary distribution line connected to the secondary side of the device under test;
The simulated distribution line capacity connected between the secondary distribution line and the ground,
A ground fault line connecting the secondary distribution line and the ground,
Rectifying element, switch and accident point occurrence equipment connected in series to the ground fault line,
A unipolar intermittent arc optical ground fault testing apparatus comprising: In the unipolar intermittent arc optical ground fault testing apparatus according to claim 1,
Unipolar intermittent arc light ground fault test equipment using a high-pressure pin insulator with cracks as the accident point occurrence equipment.

Images