JPH0318411B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a control method in a power distribution system that detects and disconnects the fault section without interruption or in the shortest possible time based on the current values of the distribution circuit breaker and the sectional switch when a fault occurs in the power distribution system. [Prior Art] Conventionally, when an accident occurs in a power distribution system, a method has been adopted in which the faulty section is detected and disconnected through trial power transmission, and power distribution is resumed to the healthy section in a short time. Figure 1 is a block diagram of the power distribution system using this method, with circuit breakers 1-1, 1-2, and 1 at substation SS.
-3, 1-4, 1-5, normally closed switch for classification 2-
1, 2-2, 2-3, 2-4, 2-5, 2-6,
2-7, 2-8, 3-1, 4-1, 5-1, 5-
2. Normally open switch for classification 2-9, 2-10, 2-1
1, distribution lines a, b, c, d, e, f, g, h, i, substation monitoring devices 7, 8, distribution line control device 9, and divisions through which power is transmitted by the circuit breaker 1-1 Switch remote control device 6, 6-1, 6-2,...
This is a distribution line made up of. Conventionally, in the control method described in Japanese Patent Publication No. 57-43021, for example, when a fault occurs on the distribution line d, the circuit breaker 1-1 of the substation SS is tripped due to an overcurrent, and the circuit breaker 1-1 of the substation SS is tripped. Waiting for re-closing, section switches 2-1, 2- are opened sequentially from the power supply side.
2 is closed, and then the fault zone is closed by the section switch 2-3, the circuit breaker 1-1 trips again, thereby determining the fault zone d. [Problem to be solved by the invention] In the case of this conventional method, after waiting for the circuit breaker 1-1 to close again,
Power is transmitted from distribution line 1-1 to b, c, and i, and distribution line 1-4, 1-5 is transmitted to sections e, f, g, and h on the load side.
There was a need to provide more flexibility for reverse transfers. In the above method, sections a, b, c, e, f, other than accident section d,
G, h, and i also involve long-term power outages, which hinders stable power supply. As social life has become more sophisticated in recent years, there has been a strong demand for improvements in the quality of electricity supply, from securing quantity to supply reliability. For this reason, it is desirable to avoid power outages as much as possible and to minimize the duration of power outages. Additionally, depending on the power company's power transmission system (especially 3-phase 4-wire system), even if an accident occurs, the circuit breakers at the substation will not trip, making it difficult to detect the fault section. I couldn't do it. The present invention has been made in view of such social demands, and aims to resume power transmission in the shortest possible time after an uninterrupted power outage or an accident occurs. [Means for solving the problem] In order to achieve this objective, the fault section detection and disconnection method in the power distribution system of the present invention applies to distribution substation buses, distribution circuit breakers, substation monitoring devices, and sectional switches. In a sectional switch operating device for a distribution system consisting of electric wires that connect these mutually, the current of the distribution substation busbar, the distribution circuit breaker, The status and current of the sectional switch are constantly input to the control device, and from this input information, the open/close status of the sectional switch connected to each distribution line breaker is determined, depending on the current value and the open/close status of the sectional switch. The power transmission route and current value from the distribution circuit breaker to each customer are always stored in the storage device of the control device, and when an accident occurs on the distribution line, the current flows to the distribution circuit breaker. Detects the occurrence of an accident based on a change in current, and detects the fault area based on changes in the current value flowing through the sectional switch belonging to the faulty distribution line at that time, based on the pre-stored opening/closing status of the sectional switch and the power transmission route. death,
The feature is that the load curve of the circuit breaker is used to calculate the reverse transmission flexibility for the section where power is being transmitted through the faulty section, the load is moved so that power is supplied from other distribution lines, and finally the faulty section is disconnected. shall be. [Operation] In the present invention, the distribution line control device periodically reads the current of each circuit breaker in the substation,
Load curves for weekdays, Sundays and public holidays (see Figure 2) are created and updated once a week. In addition, in order to monitor the distribution line, the control device reads the on/off status and current value of each circuit breaker and sectional switch at regular intervals, for example every 30 minutes or every hour, and reads the on/off status and current value of each circuit breaker and sectional switch, as shown in Table 1. The power transmission section and the section current I _k are detected in sequence and stored in the memory of the control device.

[Table] Note that the section current I _k is calculated using equation (1). I(i)=I(i) _IN −I(i) _OUT ……(1) However, I(i): Section current I(i) _IN : Inflow current into the section I(i) _OUT : Outflow from the section Outflow current The control device monitors the current of each circuit breaker in the substation SS at all times, for example every few seconds. A distribution line fault is determined only when the condition of equation (2) is satisfied. A≧B×μ+α ……(2) However, A: current of the breaker just read B: current of the breaker 1 minute ago μ: coefficient considering the load curve α: expected fault current This equation (2) If the conditions are satisfied, the control device
It is determined that an accident has occurred and the circuit breaker is designated as the accident feeder. The control device reads the current of the switch that is on the power transmission path of the accident feeder, and (1)
Using the formula, each section current I _j at the time of an accident is detected as shown in Table 2.

[Table] Also, at this time, the control device detects the expected section current I _y of the section using equation (3). I _y (i)＝B×
I _k (i) / ΣI _k (i) × μ ... (3) However, I _k (i): Previous section current ΣI _k (i): Total of previous section current belonging to the accident feeder The control device is Based on the section current I _j at the time of the accident and the expected section current I _y obtained using equations (1) and (3), a judgment is made as to whether it is normal or abnormal based on equation (4). I _j (i)≧I _y (i) + α ... (4) The interval that satisfies the condition of this formula (4) is registered in Table 3 as an abnormal interval, and the interval that does not satisfy it as a normal interval. In the above case, the control device sets the abnormal section as accident section d in Table 3.

〔Example〕

In the system of the present invention, the system itself includes circuit breakers 1-1 to 1-5, substation monitoring devices 7 and 8, and sectional switches 2-1 to 2-1 in FIG.
1, 3-1, 4-1, 5-1, 5-2, remote control device master station 6, remote control device slave stations 6-1 to 6-1
4. Consists of a distribution line control device 9. In this case, the distribution line control device 9 is the fault section detection disconnection device 9.
becomes. Each remote control device slave station 6-1 to 6-14 is connected to the remote control device master station 6 by a communication line (broken line) (partially omitted in the drawing). The control method performed by this accident section detection and separation device 9 is different from the conventional method, and the above control can be realized by a microcomputer or a minicomputer. [Effects of the Invention] As explained above, in the present invention, the current in each section is monitored, and when the magnitude of the fluctuation becomes higher than the expected value, that section is detected as abnormal and the section is opened/closed. I try to separate it depending on the container. Therefore, when detecting a faulty section, it is not necessarily necessary to shut off the substation circuit breaker, and the faulty section can be detected and disconnected without power outage or in a shorter time than before, providing high-quality power. be able to.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a power transmission system according to the present invention.
Figure 2 shows the load curve. 1-1, 1-2, 1-3, 1-4, 1-5: Substation SS circuit breaker, 2-1 to 2-8, 3-1, 4
-1, 5-1, 5-2: Normally closed switch for classification, 2-
9, 2-10, 2-1: Normally open switch for classification, a,
b, c, d, e, f, g, h, i: distribution line,
6, 6-1, 6-2 to 6-14: remote control device,
7, 8: Substation monitoring device, 9: Fault section detection and disconnection device (distribution line control device), SS: Substation.

Claims (1)

[Scope of Claims] 1. In a sectional switch operating device for a distribution system consisting of a distribution substation busbar, a distribution circuit breaker, a substation monitoring device, a sectional switch, and the electric wires that interconnect them, The current of the distribution substation busbar, the status and current of the distribution circuit breaker and sectional switch are constantly input to the control device from a correspondingly installed remote monitoring control device, etc., and each distribution The above-mentioned control of the power transmission route and current value from the distribution circuit breaker to each consumer determined by the opening/closing state and current value of the sectional switch connected to the line breaker and the opening/closing state of the sectional switch It is always stored in the device's memory device, and when an accident occurs on the distribution line, the occurrence of the accident is detected by the change in the current flowing through the distribution circuit breaker, and the opening/closing status of the sectional switch and the power transmission route are stored in advance. Based on this, the fault section is detected by the change in the current value flowing through the sectional switch belonging to the faulty distribution line at that time, and reverse transmission accommodation is implemented using the load curve of the circuit breaker for the section where power is being transmitted through the faulty section. A method for detecting and disconnecting fault sections in power distribution systems, which performs calculations, moves loads so that power is supplied from other distribution lines, and finally disconnects the fault section. 2. In the sectional switch operating device for distribution systems consisting of distribution substation busbars, distribution circuit breakers, substation monitoring equipment, sectional switches, and the wires that connect them, a remote controller installed corresponding to each sectional switch The current of the distribution substation busbar, the status and current of the distribution circuit breaker, and the sectional switch are constantly input to the control device from the monitoring control device, etc., and connections are made to the circuit breakers for each distribution line based on this input information. The current value and the power transmission route from the distribution circuit breaker to each consumer, which is determined by the open/close state of the sectional switch and the current value determined by the open/close state of the sectional switch, and the current value are always stored in the storage device of the control device. When an accident occurs on the distribution line, (a) If the distribution circuit breaker does not trip, the occurrence of the accident will be detected by the change in the current flowing through the distribution circuit breaker, and the system will be memorized in advance. Based on the opening/closing status of the sectional switch and the power transmission route, the fault section is detected based on the change in the current value flowing through the sectional switch belonging to the faulty distribution line at that time, and a circuit breaker is installed in the section where power is being transmitted through the faulty distribution line. Using the load curve, reverse transmission calculations are performed, the load is moved so that power is supplied from other distribution lines, and finally the faulty section is disconnected. (b) If the distribution circuit breaker trips, wait for the distribution circuit breaker to close again, then close the section switches one after another from the power supply side, and transfer the current flowing through the closed switches to the The faulty section is detected and disconnected based on the change from the pre-stored section current value, which is read as the section current, and then reverse transfer accommodation is performed using the circuit breaker load curve in the normal power outage section after the faulty section. Calculations are made and power is supplied from other distribution lines. (c) After the distribution circuit breaker is tripped and the distribution circuit breaker is closed again, the section switches are closed in sequence, and if the circuit breaker is tripped again by closing the section switch in the accident section, then the section is defined as the fault section, power is transmitted to the section on the power supply side of the fault section by repeatedly closing the distribution circuit breaker, and power is transferred back to the section on the load side from the distribution line on the reverse transmission side. A fault section detection and isolation method in a power distribution system is characterized by: