CN103308775B - A kind of devices and methods therefor testing interchange sea electric power cable loss induced by armour - Google Patents

Abstract

A device and method for testing AC submarine power cable armor loss, relating to a device and method for testing loss. At present, the device for testing the loss has higher requirements on the current capacity of the secondary side of the transformer, and involves the loss of the transformer, and the error of the loss test is relatively large. A device for testing the armor loss of an AC submarine power cable. The AC submarine power cable includes a wire core, a metal sheath covering the wire core, and armor. It is characterized in that: the test device includes a transformer, and a tester for detecting current and voltage The tested submarine cable connected end to end is installed on the secondary side of the transformer; the tested submarine cable passing through the transformer section is the secondary side line group of the transformer, and the rest of the tested submarine cable is the load. The technical scheme eliminates the error of the transformer loss, makes the data more real and reliable, and has lower requirements on the test equipment.

Description

A device and method for testing AC submarine power cable armor loss

technical field

The invention relates to a device and method for testing loss.

Background technique

When the conductor of a single-core submarine cable passes a large current, an induced electromotive force will be generated on the armor and the metal sheath (lead sheath), and the alternating current of the wire core will generate a changing magnetic field, which will form an eddy current on the metal sheath and the armor , resulting in eddy current losses. Due to the particularity of the operating environment of the submarine cable, the armor and metal sheath can only be interconnected and grounded at both ends of the submarine cable line, and the resulting circulation will cause a large loss. These losses are collectively referred to as armor loss. Armor loss not only increases power loss and reduces current carrying capacity, but also adversely affects the life of the insulation layer and submarine power cables. The existing method for testing the armor loss of a submarine cable is to connect a section of submarine cable in series to the secondary side of the transformer, measure the active loss of the primary side of the transformer, and subtract the loss of the transformer to calculate the total loss of the submarine cable. This method has high requirements on the current capacity of the secondary side of the transformer, and the method involves transformer loss, and the error is relatively large.

Contents of the invention

The technical problem to be solved and the technical task proposed by the present invention are to perfect and improve the existing technical solutions, and to provide a device and method for testing the armor loss of AC submarine power cables, so as to achieve the purpose of convenient operation and high test accuracy . For this reason, the present invention takes the following technical solutions.

A device for testing the armor loss of an AC submarine power cable. The AC submarine power cable includes a wire core, a metal sheath covering the wire core, and armor. It is characterized in that: the test device includes a transformer, a device for detecting current and voltage For the tester, the subsea cable under test connected end-to-end is installed on the secondary side of the transformer; the subsea cable under test passing through the transformer section is the secondary side line group of the transformer, and the rest of the subsea cable under test is the load. This technical solution directly detects the current and voltage of the tested submarine cable, and obtains the loss of the tested submarine cable and the loss of the wire core. The difference between the loss of the tested submarine cable and the loss of the wire core is the loss of the metal sheath and armor. The detection device eliminates the error of transformer loss, makes the data more authentic and reliable, and has lower requirements for test equipment.

In order to further improve and supplement the above technical solutions, the present invention also includes the following additional technical features.

The test device also includes connecting wires, stripping off the metal sheath and armor of the tested submarine cable passing through the transformer section, taking only the core of the tested submarine cable to pass through the secondary side of the transformer, and disconnecting the metal sheath and armor. The devices are communicated through connecting wires located outside the transformer. Eliminate the electromagnetic induction effect of the feedthrough transformer on its internal submarine cable lead sheath and armor. In actual production, the armor and lead cladding at both landing ends of the submarine cable are interconnected and grounded. In order to be consistent with the actual test, the lead sheath and armor at both ends of the lead-through transformer are also interconnected and connected in parallel (equivalent to grounding).

The test device includes multiple transformers, the primary side windings of the transformers are connected in parallel, and the tested submarine cable passes through each transformer in turn.

A method for testing AC submarine power cable armor loss is characterized in that it comprises the following steps:

1) The tested submarine cable passes through the secondary side of the transformer, and the tested submarine cable is connected end to end;

2) The primary side winding of the transformer is energized, the current of the core of the submarine cable under test and the voltage of the core of the submarine cable under test as the load part are obtained through the tester, and the loss of the submarine cable under test is calculated according to the measured current and voltage;

3) Calculate the core loss of the tested submarine cable according to the resistance of the core and the measured voltage;

4) The loss of the submarine cable under test is compared with the loss of the wire core to obtain the armor loss of the submarine cable.

Strip off the metal sheath and armor of the tested submarine cable that passes through the transformer section, and only take the core of the tested submarine cable to pass through the secondary side of the transformer, and the disconnected metal sheath and armor pass through the connection outside the transformer The wires are connected.

Multiple transformer primary side windings are connected in parallel to achieve a predetermined current value, and the tested submarine cable passes through each transformer secondary side in turn.

Beneficial effects: the technical solution directly detects the current and voltage of the tested submarine cable, and obtains the loss and core loss of the tested submarine cable through the tester. The difference between the loss of the tested submarine cable and the loss of the core is the value of the metal sheath and armor The loss of the equipment eliminates the error of the transformer loss, makes the data more real and reliable, and has lower requirements for the test equipment.

Description of drawings

Fig. 1 is a structural schematic diagram of the present invention.

Fig. 2 is a schematic diagram of another structure of the present invention.

In the figure: 1-transformer, 2-tester; 3-submarine cable under test; 4-wire core; 5-metal sheath and armor; 6-connecting wire.

Detailed ways

The technical solution of the present invention will be further described in detail below in conjunction with the accompanying drawings.

The AC submarine power cable includes a wire core 4 , a metal sheath covering the wire core 4 and armor 5 .

As shown in Figure 1, the present invention comprises transformer 1, the tester 2 that is used to detect voltage and electric current, and the secondary side of transformer 1 wears the tested submarine cable 3 that connects end to end, and tested submarine cable 3 passes through the transformer section as The secondary side line group of the transformer 1 and the rest of the tested submarine cable 3 are loads. The test device includes at least one transformer 1 , the primary side windings of the transformer 1 are connected in parallel, and the tested submarine cable 3 passes through each transformer 1 in turn.

As shown in Figure 2, in order to eliminate the electromagnetic induction effect of the core-through transformer 1 on its internal submarine cable lead sheath and armor, the metal sheath and armor 5 of the tested submarine cable 3 passing through the transformer 1 section are stripped, and only The core 4 of the tested submarine cable 3 passes through the secondary side of the transformer 1, and the disconnected metal sheath and armor 5 are connected through the connecting wire 6 located outside the transformer 1. The metal sheath, armor, and connecting wire electrical connection.

A method for testing losses, comprising the following steps:

1) Connect the primary side windings of multiple transformers 1 in parallel to achieve a predetermined current value, and the tested submarine cable 3 passes through the secondary side of each transformer 1 in turn; and the tested submarine cables 3 are connected end to end;

2) The primary side winding of the transformer 1 is energized, and the current of the core 4 of the tested submarine cable 3 and the voltage of the core 4 of the tested submarine cable 3 as the load part are obtained through the tester, that is, the voltage between points A and B. Obtained current and voltage are calculated to obtain the loss of the tested submarine cable 3;

3) According to the resistance of the core 4 and the measured voltage, calculate and obtain the loss of the core 4;

4) The loss of the tested submarine cable 3 is subtracted from the loss of the core 4, p=UI-I ² R, to obtain the armor loss of the submarine cable.

A kind of device and its method for testing AC submarine power cable armor loss shown in above Fig. 1, 2 are the concrete embodiment of the present invention, have reflected the outstanding substantive characteristic and remarkable progress of the present invention, can be used according to actual Need, under the enlightenment of the present invention, equivalent modification of its shape, structure and other aspects are all within the scope of protection of this scheme.

Claims (6)

1. A device for testing the armor loss of an AC submarine power cable, the AC submarine power cable includes a wire core (4), a metal sheath and armor (5) sheathed on the wire core (4), and is characterized in that: the AC submarine power cable is tested The device for armor loss of submarine power cables includes a transformer (1), a tester (2) for detecting current and voltage, and the secondary side of the transformer (1) is passed through an end-to-end AC submarine power cable (3). The power cable (3) passing through the transformer section is the secondary side line group of the transformer (1), and the rest of the AC submarine power cable (3) is the load. 2. A device for testing the armor loss of an AC submarine power cable according to claim 1, characterized in that: the device for testing the armor loss of an AC submarine power cable also includes a connecting wire (6), stripped through the transformer (1 ) section of the AC submarine power cable (3) metal sheath and armor (5), only take the core (4) of the AC submarine power cable (3) through the secondary side of the transformer (1), disconnected The metal sheath and armor (5) are communicated through connecting wires (6) located outside the transformer (1). 3. A device for testing the armor loss of an AC submarine power cable according to claim 1, characterized in that: the device for testing the armor loss of an AC submarine power cable includes a plurality of transformers (1), and the primary transformer (1) The side windings are connected in parallel, and the AC submarine power cable (3) passes through each transformer (1) in turn. 4. a method for the device test loss that adopts the test AC submarine power cable armor loss described in claim 1, is characterized in that it comprises the following steps: The AC submarine power cable (3) passes through the secondary side of the transformer (1), and the AC submarine power cable (3) is connected end to end; The primary side winding of the transformer (1) is energized, and the current of the core (4) of the AC submarine power cable (3) and the voltage of the core (4) of the AC submarine power cable (3) as the load part are measured by the tester. The current and voltage are calculated to obtain the loss of the AC submarine power cable (3); Calculate the loss of the AC submarine power cable (3) core (4) according to the resistance of the core (4) and the measured voltage; The loss of the AC submarine power cable (3) is subtracted from the loss of the wire core (4) to obtain the armor loss of the AC submarine power cable. 5. The method for testing loss according to claim 4, characterized in that: the metal sheath and armor (5) of the AC submarine power cable (3) passing through the transformer (1) section are stripped, and only the AC submarine power is taken The core (4) of the cable (3) passes through the secondary side of the transformer (1), and the disconnected metal sheath and armor (5) are connected through the connecting wire (6) located outside the transformer (1). 6. The method for testing loss according to claim 5, characterized in that: the primary side windings of multiple transformers (1) are connected in parallel to reach a predetermined current value, and the AC submarine power cable (3) passes through each transformer ( 1) Secondary side.