JPS6223313A - Warning of ground trouble - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is utilized as a method for warning of a spillover accident location due to a grounding fault within a customer-side liability demarcation point in a high-voltage distribution line.

(Conventional technology) Among power outage accidents on power company distribution lines, there is a tendency for spillover power outages caused by failures of high-voltage customers to increase, and the failure rate is particularly high for aerial switches that are exposed to wind, rain, and snow damage. The current situation has developed into a social problem, including other grounding failures. Therefore, as a countermeasure against malfunctions of air switches at high-voltage consumers, a protective device is used to prevent spillover accidents by disconnecting only the company's premises from the distribution line using a grounding device. Prepared! There are some important people, but they are not using the same protection device because of the high price and the inability to work on live wires, which increases construction costs. The air switch provided with the equipment was not used thoroughly,
Most of them are in a state of protection against grounding faults, and these customers are at risk of causing spillover accidents, so there has been a demand for countermeasures against grounding faults that can be solved at low cost.

(Problems to be Solved by the Invention) In view of the above circumstances, the present invention provides a method for preventing spillover accidents that can occur during live line work without replacing conventional power receiving equipment, etc., that is, a method for warning of spillover accident locations due to grounding failures. This is what we are trying to provide.

(Means for Solving the Problems) The present invention detects a ground fault current within a customer liability demarcation point, and in this case, it is determined that the detected ground fault current has a current value greater than the self-charging current, and that an accident has occurred. As a condition for power cut-off, an alarm means is activated by the emergency power supply to alert the user to the location where a ground fault has occurred.

(Function) According to the above means, countermeasure work against grounding faults can be carried out by live wire work.1. When a failure occurs, it will alert you to the location where it has occurred, so you don't have to spend time searching for it.

(Example) Hereinafter, the present invention will be explained in detail using an example.
As shown in the figure, the power distribution line from the electric power company generally supplies power to the consumer at the responsible demarcation point a, and then the power is supplied to each power receiving equipment 4 in the power receiving room 6 on the premises by the high voltage lead-in cable 2 via the air switch 1. However, the present invention provides an air switch 1
By simply turning off the switch, the shield wire 5 of the high-voltage drop-in cable 2 is connected to the ground terminal 6 of the air switch 'a1, and the air switch 1, the drop-in cable 2, the power receiving equipment 4, etc. are connected as shown in Fig. 2. The ground fault current is detected by the ground fault current detection unit (zero-phase current transformer), and the ground fault current is detected by the ground fault relay 7, and if the ground fault current is higher than the self-charging current of each consumer unit and the power supply is cut off, the ground fault current is detected by the ground fault current detection unit (zero-phase current transformer). Using the emergency power source 8'ft for emergency lights, the occurrence of an accident can be mechanically indicated on the spillover accident indicator 9, or the location of the accident can be perceived by warning means such as an electrical buzzer or a turning light. In this embodiment, an autonomous security means 3 is incorporated in addition to the present invention. That is, as shown in FIG. 3, the ground fault current detected by the ground fault current detection section passes through the sensitivity adjustment section and enters the ground fault relay 7, and at the light ground fault detection g7', the ground fault current is set to a predetermined setting value below the self-charging current. After confirming this, the relay 10 is activated, and when the first stage alarm, which is a self-protection means, is turned on, the A contact 10' is closed and the buzzer 11 sounds to issue an alarm.

If inspection and repair are carried out at this stage, a spillover accident will not develop, but if it is overlooked and the ground fault current reaches a predetermined value higher than the self-charging current, heavy ground fault detection g7 of the ground fault relay 7 will occur.
Activate the relay 12 at the point A of the second stage alarm
If contact 12' is closed and a spillover accident occurs in this state, A
Since the power of OiQQV is cut off, in response to the command from relay 16, close BW point 16'', turn on pilot lamp 14, activate relay 15, close A contact 15' in the spillover accident display section, and turn on relay 16. When activated, the spillover accident indicator 9 is activated by appropriate warning means as described above.Therefore, when the present invention is applied,
In the unlikely event that a ground fault occurs and the power is cut off from the power supply side, the customer at the source of the accident can of course confirm that the accident has occurred, and the electric power company can quickly confirm this from the outside, so the location of the accident can be confirmed. It is possible to quickly respond to recovery without requiring time and effort for searching, and to minimize damage caused by spillover accidents.

(Effects of the Invention) According to the present invention, countermeasures against grounding faults can be carried out by live-line work, so the cost of the work is low, and even if the power supply on the power supply side is cut off due to the occurrence of a spillover accident, the location of the fault can be fixed. It is clear that since it can be confirmed quickly by both the user and others, damage caused by spillover accidents can be minimized, and the needs of consumers and electric power companies can be fully met.

[Brief explanation of drawings]

Fig. 1 is a schematic explanatory diagram of a ground fault sensing device (hereinafter referred to as this device) according to the present invention, Fig. 2 is an enlarged schematic diagram of a ground fault current detection section, and Fig. 6 is an electric circuit of this device. It is a diagram. In the figure, 1 is an air switch, 2 is a lead-in cable, 3 is a power receiving room, 4 is power receiving equipment, 5 is a shielded wire, 6 is a ground terminal,
7 is a ground fault relay, 8 is an emergency power supply, 9 is a spillover accident indicator, 10.12.16.15.16 is a relay, 11 is a buzzer, and 14 is a pilot lamp. A is the demarcation point of responsibility.

Claims (1)

[Claims] Detects ground fault current within the customer's responsibility demarcation point, and uses emergency power to alert the location of the ground fault if the current value is greater than the self-charging current and the power is shut off. A ground fault warning method characterized by: