JPH01311820A - Detection of accident point in closed-loop distribution system - Google Patents

Abstract

PURPOSE:To detach an accident section quickly by operating only a detecting relay connected to the ON contact of a direction relay nearest to an accident point in direction relays worked when an accident is generated in both directions of a closed loop. CONSTITUTION:When an accident is generated at a point B, direction relays R24, R23, R22, R21 viewing an accident point in the direction of a control power are operated because there is the accident point at a section nearer to the control power than the direction relay R24, and R25 is not worked. Consequently, currents are made to flow only through a relay coil r24, and a trip signal is transmitted over a breaker S24. Likewise, direction relays R12, R11 viewing the accident point in the direction of the control power are operated because there is the accident point B at a section nearer to the control power than the direction relay R12, and R13, R14, R15 are not worked. Accordingly, currents are made to flow only through a relay coil r12, and a trip signal is transmitted over a breaker S12.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a method for detecting fault points that occur in a closed-loop power distribution system. Accidents that occur in a closed loop that has a branch point where the feeder line that supplies current to the load branches or a division point where a division switch is installed to divide the closed loop into appropriate lengths, Method 1 for promptly detecting fault points that occur in a closed loop power distribution system equipped with directional relays that are arranged at both ends of a section between adjacent branch points or division points and whose detection directions are directed toward the inside of this section. Related 6 [Prior Art] Conventional protection methods in closed-loop distribution systems include A grounding detection device, an overcurrent detection device (#) and a ζ breaker are installed at both ends of the section between the two branching points or division points, and the detection elements of the respective grounding detection devices in the same section are connected to each other. The detection elements of the flow detection device are connected to each other by two pilot wires, and the detection device connected between these two pilot wires detects the occurrence of an accident within that section. A pyro system that determines whether there is an accident or not, and when it determines that there is an accident within that section, simultaneously releases the Li thickness cutters at both ends of that section.

[・Wire relay method and directional relay shown in Figure 2 1・
There is one method in the direction 1Jy in which each of R1, ~rtls, R21~R2s is combined with a timer to separate the section where the accident point exists from the closed loop. In this one-direction relay type, the operating time of each direction relay R1□~Rxs, R21~fezs when combined with a timer is 'I'll~TIs*T=r-'':'5 is T15 <T14 <TI3 <T12 <Tll and T25 < T24 < Tzy+ < T22 <
Each timer is set to T21, and A
When a point fault occurs, the combination of directional relay all and its timer as well as the combination of directional relay 1 (25) and its timer 7 are activated, so that only the section where the fault point A exists is separated from the closed loop.

[Problem to be solved by the invention]

Of the aforementioned protection methods for closed-loop distribution systems, pilot wire! ! The electric method can detect faults without delay and has excellent protection performance as a section protection method, but it is quite expensive. On the other hand, the one-way directional relay type is an inexpensive and simple protection system, but when there are many branching points or division points, the number of timers combined with the directional relay increases, and accordingly, the number of time limits that must be set increases. Therefore, depending on the number of accident points, it takes a long time until the accident section is separated from the closed loop, and there is a risk that the accident will spread.

The object of the present invention is to eliminate the above-mentioned drawbacks of the one-way directional relay type, eliminate the time delay until the fault point is detected, and therefore quickly disconnect the section where the fault point exists from the closed loop M, -
4- To provide a method for detecting fault points that is possible and inexpensive.

[Means to solve the problem]

In order to achieve the above object, according to the present invention, a branch point where a feeder line that is formed with a closed loop 6 that is supplied with power from a distribution power source and that supplies current to a load branches is also provided. < indicates an accident that has occurred in the closed loop, which has a dividing point where a dividing switch is installed to divide the closed loop into appropriate lengths, at an adjacent branch point or dividing point on this closed loop. The detection direction is 7'11.
A closed-loop power distribution system equipped with a directional relay in the direction toward this section (as a method of detecting a fault point that has occurred, the closed-loop power supply is 1) A first connecting the off contact gaps in the on/off switching contacts in series, extending in one direction along the direction and having the detection direction opposite to this direction.
and a second control line that comes out from the other terminal of the control power source and extends parallel to the first control line to connect the on contact of the on/off switching contact to the second control line. between the control line (a detection relay is arranged for each, and a third control line and a fourth control line are similarly drawn out from the control power source in the opposite direction of the closed loop, and a detection relay is arranged, and a detection relay is arranged on the closed loop. The ON contact of the directional relay closest to the accident point among the directional relays that operated when the accident occurred (by activating only the connected detection relay in both directions in a closed loop, the section between branch points or division point where the accident point exists) The method shall be one that detects the interval.

[Effect]

Configuring the circuit for fault point detection in this way (
Therefore, if an accident occurs in any section in the closed loop, the control power supply (closer section) than this section (therefore, the direction relay whose detection direction is in the direction of the control power supply will not operate and its OFF contact will remain closed). Since the voltage of the control power supply is transmitted to a further distance via the off contact of this non-operating direction relay, the detection direction is in the direction of the control power supply in this fault section and in the section farther from this fault section. Since the directional relay operates and switches its OFF contact to the ON contact, the voltage of the control power supply reaches the ON/OFF switching contact of the directional relay that is in the accident zone and has the detection direction in the direction of the control power supply, It does not reach the on/off switching contact of the direction relay in the accident section.As a result, among the direction relays whose detection direction is in the direction of the control power supply, only the detection relay connected to the on contact of the direction relay in the accident section is activated. , and since there is one activated detection relay at each end of the accident section, the accident section is quickly separated from the closed loop without delay.

〔Example〕

Figure 1 shows an embodiment of the detection circuit configuration that enables the fault point detection method of the present invention.If an accident occurs at point B in Figure 2, this fault point is connected to direction relay R2A. Since it is located closer to the control power source, the direction relay R44* R23* ”2 looks at the fault point toward the control power source.
2 e When R21 is activated, there is no fault point near the control power source of direction relay R25, so direction relay R is activated.
ZS does not work. Therefore, in Fig. 2, the direction relay R
24+ RZi * R22+ "The on/off switching contact of 21 switches from the off position to the on position, and the on/off switching contact of directional relay R25 remains closed at the off position fR1. Therefore, the voltage of the control power supply is It reaches the on contact of direction relay R24 via the off contact of direction relay R25, and then reaches the on contact of direction relay R24, which is further away from this,
R22* It does not reach the on/off switching contact of R21. For this reason, each on contact of the direction relay and the second
Detection relay r25 e 1 arranged between control line 2 of
24 + rzs l '22 e r2 out of r21
Current flows only through the operating coil No. 4 to close the contacts of this relay, and a trip signal is sent to circuit breaker S24. Similarly, since this accident point B exists closer to the control power source than the direction relay R1
e Since there is no fault point near the control power source of R14 and R15, the directional relay R13e "14 tRI5 does not operate. Therefore, the voltage of the control power source is the same as the directional relay R15+.
”14 r Direction relay R via the off contact of R13
12 on contact, and the direction relay a further away from this
The on/off switching contact 1 of 11 is not reached. For this reason, each on contact of the direction relay and the fourth control line 4
Detection relay r15 + '! 4 + r
13*r12*rlJ, current flows only through the operating coil of r12 to close the contacts of this relay, and a trip signal is sent to circuit breaker S12.

In this way, detection relays r25~r21, r15~rl
Since the operation of l is performed without using a timer, no matter where the fault point occurs on the closed loop,
No matter how many branching points or dividing points there are, there is always a
It becomes possible to detect the accident point only by the delay in the operation time of the direction relay and the detection relay, and it is possible to prevent the danger of the accident from spreading.

〔Effect of the invention〕

As described above, according to the present invention, there is provided a branch point where a feeder line formed in a closed loop supplied with power from a distribution power source and which supplies current to a load branches, or a branch point for dividing the closed loop into appropriate lengths. Accidents that occur in the closed loop that has a dividing point where a dividing switch is installed are detected at both ends of the section between adjacent branch points or dividing points on this closed loop, and the detection direction is directed toward the inside of this section. As a method for detecting fault points that occur in a closed-loop power distribution system equipped with directional relays, one terminal of a control power source placed at the distribution power source position is extended in one direction along the closed loop, and a first control line connecting in series the off-contact gaps of the on-off switching contacts of the directional relay with detection directions in opposite directions; wc2 extending parallel to
A detection relay is provided between the on contact of the on/off switching contact and the second control line, and a third control line is provided in the opposite direction of the closed loop from the control power source. A detection relay is placed by pulling out the control line and the fourth control line, and only the detection relay that is connected to the on contact of the direction relay closest to the accident point among the direction relays that operated when the accident occurred on the closed loop is connected to the closed loop. This method detects the section between branch points or the section between section points where an accident point exists by operating and tightening in both directions, so no matter how many branch points or section points there are on the closed loop,
In addition, even if an accident occurs in any section between junctions or sections between division points, the accident point can be detected only by the time delay between the operation times of the direction relay and detection relay, regardless of these factors. This makes it possible to provide zone protection with excellent protection performance without the risk of escalating an accident using an inexpensive directional relay type, and its economic effects are significant.

[Brief explanation of the drawing]

FIG. 1 is a circuit configuration diagram for detecting a fault point according to an embodiment of the present invention, and FIG. 2 is a circuit diagram using a direction switch. FIG. 2 is a circuit configuration diagram for detecting a fault point according to a conventional example.

Claims (1)

[Claims] 1) It is formed into a closed loop fed from a distribution power source and has a branch point where the feeder line that supplies current to the load branches, or a dividing point where a dividing switch is installed to divide the closed loop into appropriate lengths. A fault occurring in the closed loop is detected in a closed loop power distribution system equipped with directional relays arranged at both ends of a section between adjacent branch points or division points on this closed loop, and whose detection direction is directed toward the inside of this section. A method for detecting a fault point in a direction extending in one direction along the closed loop from one terminal of a control power source disposed at the distribution power source position and having a detection direction in the opposite direction. a first control line that connects in series the off contact gaps of the on/off switching contacts of the relay; and a second control line that comes out from the other terminal of the control power source and extends parallel to the first control line. A detection relay is disposed between the on contact of the on/off switching contact and the second control line, and a third control line is similarly arranged in the opposite direction of the closed loop from the control power source. A detection relay is installed by pulling out the fourth control line, and only the detection relay connected to the ON contact of the direction relay closest to the accident point among the direction relays activated when an accident occurs on the closed loop is activated in both directions of the closed loop. A method for detecting a fault point in a closed loop power distribution system, characterized by detecting a section between branch points or a section between division points in which a fault point exists by detecting the fault point.