JPS59169009A - Dc breaker - 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 Application of the Invention] The present invention relates to a DC breaker, and particularly to a DC breaker suitable for application to a high voltage system.

[Prior art] In order to improve the operational reliability of DC power transmission systems, the application of DC circuit breakers is being researched, but since DC has a force different from AC and no natural current zero point, special measures are required to interrupt it. It is.

The flow breaker method applied to DC transmission systems is as follows:
A common method is to superimpose a high frequency oscillation s'rm flow on the DC flowing through the breaker, generate all WIJ flow zero points, and interrupt the current in the same way as an AC breaker. Of this method, high frequency oscillating current? The method of charging a capacitor for generating electricity using the voltage of the transmission line has a simple structure, can cut off large currents, and is excellent in both reliability and economy. However, this method requires a high-speed switching device to quickly generate high-frequency oscillating current when shutting off, and the closing time of this switching device determines the DC or disconnection time. .

Also, the voltage on the power transmission line drops when the power is being transmitted and is waiting in an alley, but does the capacitor discharge at this time? Prevent high-frequency currents from burning? In order to quickly charge the capacitor at the required time and in the required amount in preparation for the cut-off and re-opening, it is necessary to switch the resistance of the charging resistor at high speed. equipment is required.

[Purpose of the invention]

What is the purpose of the present invention? The opening/closing operation of the 2 types of opening/closing devices to be determined is accurate and fast, and has excellent reliability and economical efficiency.
It's all about providing.

[Summary of the invention]

In the present invention, when the DC current is cut off, the switching device for allowing the current to flow into the cutoff section when the current is inserted into the DC current, and the operating device r for the switching device for holding the resistance ik+f of the charging resistor have almost the same structure,
Is it possible to achieve the required performance by mechanically connecting both switchgears so that their opening and closing operations are reversed? It's something you get.

(3) In other words, for operating devices that require high speed, the speed response for one-way operation is generally an obstacle for reverse direction operation, and if one direction operation is fast, the other direction operation is relatively slow. Become. The present invention makes full use of this difference in characteristics.

Examples Below are examples of the present invention. Take a close look at Figures 1 and 2. FIG. 1 shows the circuit configuration of a DC breaker which uses the voltages r and U of the power transmission lines lj and 8, which are connected to the charging capacitor 2, which is the source of the frequency oscillation kJJ current.

FIGS. 2A and 2B show the operation sequence of each switching device of the direct R, , L- and disconnectors shown in FIG. 1. In the same figure, the solid lines are between each interval (a)
The electrical contacts or parts of the device are shown, and the dashed lines indicate the positions of the contacts in a simulated manner. In the same figure, A is the breaker l
The operation is shown, and the contact is opened at time 11 according to the cutoff command 17. In the closing switch 4 indicated by B, the mechanical connection between the electrical contact and the operating device is reversed from the normal one, so the breaker l and the reverse VC operate in the same way. Therefore, if a closing command is issued at the same time as a shutoff command, the closing command will be turned on at an appropriate time delay point 12.

(4) With this closing operation, the capacitor 2, which is constantly charged from the power transmission line via the charging resistor 6.7r, is transferred to the reactor 3.
The generated one-frequency oscillating current is superimposed on the DC current flowing through the breaker l to generate a current zero point, and the DC is interrupted. As indicated by the cutoff point C, the changeover switch 5 is turned on at time 13 to short-circuit the 6 high resistances and quickly charge the 2 capacitors by the low resistance 7 in preparation for reclosing. In this way, the mechanical connection between the electrical contacts of the closing switch 4 and the operating device is reversed to that of the changeover switch 5 to enable high-speed closing, and the other structures are exactly the same.
Enables high-speed reclosing Mk.

The operating device for the closing switch 4, which is a device having such a closing function and the minute M function, and the operating device for the selector switch 5 for switching the charging resistor 6°7r have the same structure.
It is possible to connect one of the direction changing levers r to a link system in the middle.

〔Effect of the invention〕

According to the present invention, it is possible to provide a DC breaker that allows the closing switch and the changeover switch to have the same structure, enables high-speed shutoff and high-speed closing, and is excellent in both reliability and economy.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a south current breaker, and FIG. 2 is an operation sequence of each switch of a DC breaker to which the present invention is applied.

Claims (1)

[Claims] 1. A cut-off part is provided in the DC power transmission system, and a capacitor and a reactor for flowing a high-frequency current 'ff: into this cut-off part, as well as a device having an electrical input function and a separation function, are connected in parallel to the above cut-off part, and the capacitor One terminal of a charging resistor that is charged by the voltage of a DC transmission line is connected between the capacitor and the above-mentioned device having an electrical input function and a separation function, and the other terminal is connected to the ground or a neutral wire. and the resistance value r of the charging resistor
@In a flow breaker equipped with a changeover switch, is the electrical closing function and separation function described above? The operating device of the device and the operating device of the changeover switch @r have almost the same structure, and the mechanical connection t between the electrical contact part of the device and the operating device, and the electrical contact part of the changeover switch and the operating device A DC breaker characterized by being connected so that the mechanical connection and opening/closing operation are reversed.