SU565262A1 - Device for detecting power cables insulation damage spot - Google Patents

Description

one

This invention relates to the field of electrical measuring technology. The device can be used in energy systems, in particular, in energy utilities of cities and industrial enterprises.

A device for determining the location of insulation damage is known, based on recording the time interval between current pulses arriving at the cable ends from the point of occurrence of a defect, containing a high-voltage source connected to one of the cable cores, two impulse sensors resulting from a breakdown of electrical strength of the insulation. cable in the event of incomplete or polyohs, connected to the unit for measuring the time interval and installed at opposite ends of the cable, an additional communication line with corrective nodes that synchronize the operation of the counters and the time interval measurement circuit.

The disadvantages of a lime device are the lack of accuracy in determining the location of the damage and operational inconvenience caused by the presence of an additional communication line.

The purpose of the invention is to improve the accuracy of determining the location of damage and simplify the process of exploitation. This is achieved in the proposed device for determining the location of damage to the insulation of power cables in that the pulse sensors are connected at one end to two test wires that are interconnected at the opposite end.

The drawing shows an electrical block diagram of the device.

The device consists of sensors 1, 2 pulses, a high-voltage source 3 and a unit for measuring the time interval containing an electronic switch 4, a counter 5 pulses, an indicator 6 and a generator 7 of pulses.

Sensors 1 and 2 are connected on one ring of the test cable 8 to two conductors, which at the other end are interconnected, and one of the conductors of the cable is connected to a high-voltage source 3. The time interval measurement unit is connected to the outputs of the sensors 1 and 2 pulses.

The device works as follows. The signal from sensor 1 or 2, to which the pulse generated by the isolation breakdown had previously approached, opens the key 4. The normalized pulses from the generator 7 are fed to the input

counter 5. The signal from sensor 1 or 2, to which the pulse generated by the isolation breakdown comes up later, closes the key, interrupting the arrival of pulses from the generator to the counter input.

Impulses that occur at the place of incomplete Horo or a complete breakdown of cable insulation, are fed to the inputs of sensors 1 and 2 with a temporary

2 / at intervals t -, where / is the distance from

damage to the shorted end of the cable, V is the velocity of wave propagation in the cable.

The number of counted pulses, proportional to the measured time interval, is recorded by indicator 6.

The inclusion of sensors at one end of the test cable eliminates the need to use two time meters, which eliminates the additional communication line and correction device, which increases the noise immunity, operational reliability, simplifies the maintenance of the device and improves the measurement accuracy.

Claims (1)

Invention Formula A device for determining the location of damage to the insulation of power cables, containing a high-voltage source connected to one of the cable cores, two impulse sensors generated as a result of a breakdown of the electrical strength of the INSULATIONS of the Cable during incomplete or complete breakdowns, connected to a time measurement unit, that, in order to improve the accuracy of determining the location of damage and simplify the process of operation, the pulse sensors are connected at one end of the cable to the two test wires that dineny interconnected at the opposite end.