JPH077849A - Constant direct current feeder - Google Patents

Abstract

PURPOSE:To detect ground faults in the vicinity of an equal load sharing point at the time of feeding, in a submarine cable system. CONSTITUTION:Ground faults at an equal load sharing point of a submarine cable system are detected by providing a timer and a current control panel CUR.CONT in a power monitor rack PM, in addition to a conventional feeder, causing the output of the current control panel CUR.CONT to graduate stepwise in accordance with the output signal of the timer, and causing the output current or voltage of the feeder to increase or decrease stepwise.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distant constant-current power supply device returning to the earth, and more particularly to a constant-current DC power supply device for supplying power to submarine equipment such as a submarine cable system.

[0002]

2. Description of the Related Art A power feeding device used in a conventional submarine cable system is shown in FIG. BACKGROUND ART A conventional power supply device includes a power regulator (PR) rack that boosts a device input voltage by an inverter system, a power monitor (PM) rack that controls a voltage and a current of a power regulator rack output to have required characteristics, and a power monitor rack. It consists of a load switching (LT) rack and a pseudo load (TL) rack that can switch the output to a submarine cable or a pseudo load.

[0003]

The power supply to the submarine cable system is a distant constant current power supply system with the earth as a return path, and the power supply to the submarine equipment is equal to that of the power supply device installed in the opposite station. We share.

Therefore, when a ground fault occurs in the submarine cable or submarine equipment near the equal load point, there is a problem that the conventional power feeding device cannot detect the fault.

An object of the present invention is to provide a constant current DC power supply device which solves such a problem.

[0006]

DISCLOSURE OF THE INVENTION The present invention is a constant current DC power supply device installed in its own station and an opposite station for supplying power to submarine equipment, and a power regulator rack for boosting the device input voltage, A power monitor rack for monitoring the voltage and current of the power regulator rack and changing the output of the power regulator rack; a current control panel connected to the power monitor rack; and a timer for supplying a control current to the current control panel. A load switching rack for switching and connecting the output of the power monitor rack to a load or a pseudo load, and a pseudo load rack.

[0007]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a conceptual diagram of a power feeding device according to the present invention.

Regarding the power regulator (PR) rack, load switching (LT) rack, and pseudo load (TL) rack,
The same as before. That is, the power regulator rack boosts the device input voltage by an inverter system, the load switching rack switches the output of a power monitor (PM) rack to be described later to a submarine cable or a pseudo load, and the TL rack is a pseudo load rack.

The power monitor (PM) rack monitors the output voltage and current, and also has each adjusting section so that various characteristics (output voltage and current) of the apparatus have predetermined characteristics.
A control unit is provided so that the rack output characteristics are constant. A current control board (CUR.CONT) is newly connected to this control unit, and the PR rack output voltage and current are changed according to the output signal of the current control board. Further, a timer (TIMER) connected to the current control panel outputs a control signal to the current control panel according to the set time or elapsed time.

Generally, in a submarine cable system, a power supply device installed in its own station and an opposite station shares the load as shown in FIG. 2 to supply power to the submarine equipment. The broken line in the figure represents the change in the output voltage (current) of the power feeding device of the opposite station when the output voltage (current) of the power feeding device of one station is changed, and the voltage slope in the system length direction.

The power feeding device of the present invention utilizes this function,
As shown in FIG. 3, the power supply device output current of one station is intentionally changed in steps. This is done by changing the output of the current control board in steps according to the timer output signal.

As shown in the figure, the stationary feed current I _{1 of} station A is
Is increased by ΔI, the power supply device output current I _{2 of} station B, which is the opposite station, is also increased by ΔI. On the other hand, as shown in FIG. 3, with respect to the power supply voltage, when the power supply device output voltage of one station is increased, the opposite station power supply output voltage is decreased.

However, when a submarine device such as a submarine cable falls into a ground fault, a feed return path is formed at the ground fault point. Therefore, as shown in FIG. Opposite station power supply device output current does not change (same for voltage). As a result, ground faults near the uniform load point of the submarine cable system can be clearly detected.

[0015]

As described above, since the power supply to the submarine cable system is the distant constant current power supply system between the two stations, the power supply device output current or voltage of one station is increased or decreased as in the present invention. As a result, the power supply device output current or voltage of the opposite station can be increased or decreased. Thereby, the ground fault in the vicinity of the equal load point can be detected by monitoring the output characteristics of the opposite station power supply device.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of a power supply device according to the present invention.

FIG. 2 is a diagram showing a submarine cable system power supply voltage gradient.

FIG. 3 is a diagram showing an output current of a power supply device according to the present invention.

FIG. 4 is a diagram showing a change in current when a ground fault occurs.

FIG. 5 is a conceptual diagram of a power supply device according to a conventional technique.

[Explanation of symbols]

 PR Power regulator rack PM Power monitor rack LT Load switching rack TL Pseudo load rack CUR. CONT current control panel 2 TIMER timer

Claims (2)

[Claims] 1. A power regulator rack for boosting an input voltage of a constant current DC power feeder installed in a local station and an opposite station for supplying power to a submarine device, and voltage and current of the power regulator rack. A power monitor rack for monitoring the output of the power regulator rack, changing the output of the power regulator rack, a current control panel connected to the power monitor rack, a timer for supplying a control current to the current control panel, and a load for the power monitor rack output. Alternatively, a constant current DC power supply device comprising a load switching rack for switching and connecting to a pseudo load and a pseudo load rack. 2. A constant current DC power supply device characterized in that the current control board is controlled by a control current of the timer to increase or decrease the output of the power regulator rack stepwise.