CN106569065B - A DC cable thermal cycle voltage test device - Google Patents

Abstract

The utility model relates to a thermal cycle voltage test device for a DC cable, which relates to a thermal cycle voltage test device for a DC cable. The existing DC cable thermal cycle voltage test device adopts a pass-through cable heating transformer, and the AC heating method changes the electric field distribution while changing the temperature distribution of the cable, so that the test cannot truly reflect the operating status of the cable, and there are defects. The invention comprises a step-up transformer and a rectifier bridge electrically connected with the step-up transformer, the rectifier bridge is provided with a first output terminal and a second output terminal, and a DC cable for testing is connected between the first output terminal and the second output terminal , the high potential end of the test DC cable is connected to the DC high voltage generator. In this technical solution, by using direct current instead of traditional induced alternating current for thermal cycle voltage test, it can truly simulate the actual operating condition of the direct current cable, making the test closer to the actual working condition.

Description

A DC cable thermal cycle voltage test device

technical field

The invention relates to a thermal cycle voltage test device for DC cables.

Background technique

The existing DC cable thermal cycle voltage test device adopts a piercing cable heating transformer, and uses the induced AC current to conduct the heating test, while the DC cable passes a DC current during actual operation, and the AC heating method will cause the outer metal sheath to produce damage. Circulation loss, and then change the temperature distribution from the inside to the outside of the cable. The electric field distribution of the cable is directly related to the temperature. The AC heating method changes the electric field distribution while changing the temperature distribution of the cable, so that the test cannot truly reflect the operation of the cable. defect.

Contents of the invention

The technical problem to be solved and the technical task proposed by the present invention are to improve and improve the existing technical solutions, and to provide a DC cable thermal cycle voltage test device for the purpose of better simulating the actual operating conditions of the DC cable. For this reason, the present invention takes the following technical solutions.

A DC cable thermal cycle voltage test device, comprising a step-up transformer, a rectifier bridge electrically connected to the step-up transformer, the rectifier bridge is provided with a first output end and a second output end, the first output end and the second output end The test DC cable is connected between the terminals, and the high potential end of the test DC cable is connected to the DC high voltage generator. The DC heating and voltage test of the DC cable used in the test is realized through the step-up transformer, rectifier bridge and DC high-voltage generator. The simulation effect is almost the same as the working state of the DC cable, which is more in line with the actual application status of the DC cable.

As a further improvement and supplement to the above technical solutions, the present invention also includes the following additional technical features.

The rectifier bridge is supported by the supporting insulating pillars arranged under it. The supporting insulating column provides support for the rectifier bridge, and because of its insulating properties, no electrical connection occurs, which improves the working reliability of the rectifier bridge.

The rectifier bridge is a PWM rectifier bridge. PWM control is simple and flexible, with good dynamic response and strong flow capacity.

The supporting insulating column is grounded. It can effectively deal with the induced charge and static charge generated on the supporting insulating column, and improve the safety of the rectifier bridge.

The step-up transformer is an output voltage adjustable transformer. By adjusting the output pressure, the required output pressure is provided.

Beneficial effects: by using direct current instead of traditional induced alternating current to carry out thermal cycle voltage test, the actual operating condition of the direct current cable can be truly simulated, making the test closer to the actual working condition.

Description of drawings

Fig. 1 is a schematic diagram of the circuit structure of the present invention.

In the figure, 1-step-up transformer; 2-supporting insulating column; 3-DC cable for test; 4-first output terminal; 5-second output terminal; 6-DC high voltage generator; 7-rectifier bridge.

Detailed ways

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

As shown in Figure 1, a kind of DC cable thermal cycle voltage test device comprises a step-up transformer 1, a rectifier bridge 7 electrically connected with the step-up transformer 1, and the rectifier bridge 7 is provided with a first output terminal 4 and a second The output terminal 5 is connected to the test DC cable 3 between the first output terminal 4 and the second output terminal 5 , and the high potential end of the test DC cable 3 is connected to the DC high voltage generator 6 . The DC heating of the test DC cable 3 is realized through the step-up transformer 1, the rectifier bridge 7 and the DC high-voltage generator 6. The simulated test conditions are consistent with the working conditions of the DC cable 3, which is more in line with the actual application conditions of the DC cable 3.

In order to provide support for the rectifier bridge 7, the rectifier bridge 7 is supported by the support insulating column 2 provided thereunder. The supporting insulating column 2 provides support for the rectifier bridge 7 and does not conduct electricity due to its insulating properties, which improves the working reliability of the rectifier bridge 7 .

For ease of control, the rectifier bridge 7 is a PWM rectifier bridge 7 . PWM control is simple and flexible, with good dynamic response and strong flow capacity.

In order to improve safety, the supporting insulating column 2 is grounded. The induced charge and static charge generated on the supporting insulating column 2 can be effectively dealt with, and the safety of the rectifier bridge 7 is improved.

In order to adjust the output voltage conveniently, the step-up transformer 1 is an output voltage adjustable transformer. By adjusting the output pressure, the required output pressure is provided.

During the test, the step-up transformer 1 takes a certain voltage difference at the high potential end on the step-up side of the transformer, and outputs it to the PWM rectifier bridge 7 after rectification. The first output terminal 4 and the second output terminal 5 of the PWM rectifier bridge 7 are connected for testing. The DC cable 3, the high potential end of the test DC cable 3 is connected to the DC high voltage generator 6, and the DC high voltage generator 6 can adjust the current and voltage according to the test requirements.

In this example, the low potential end of the boost side of the step-up transformer 1 is grounded, and the DC high voltage generator 6 is grounded.

A kind of DC cable thermal cycle voltage test device shown in above Fig. 1 is the concrete embodiment of the present invention, has embodied the substantive characteristic and progress of the present invention, can according to actual use needs, under enlightenment of the present invention, to its Equivalent modifications in aspects such as shape and structure are all within the scope of protection of this scheme.

Claims (5)

1. A direct current cable thermal cycle voltage test device, its characterized in that: the high-voltage direct-current power supply comprises a step-up transformer (1) and a rectifier bridge (7) electrically connected with the step-up transformer (1), wherein the rectifier bridge (7) is provided with a first output end (4) and a second output end (5), a direct-current cable (3) for test is connected between the first output end (4) and the second output end (5), and a high-potential end of the direct-current cable (3) for test is connected to a direct-current high-voltage generator (6); the low potential ground of the boost side of the boost transformer (1) is grounded, and the direct current high voltage generator (6) is grounded.

2. The direct current cable thermal cycle voltage test apparatus according to claim 1, wherein: the rectifier bridge (7) is supported by a supporting insulating column (2) arranged below the rectifier bridge.

3. The direct current cable thermal cycle voltage test apparatus according to claim 1, wherein: the rectifier bridge (7) is a PWM rectifier bridge (7).

4. The direct current cable thermal cycle voltage test apparatus according to claim 2, wherein: the supporting insulating column (2) is grounded.

5. The direct current cable thermal cycle voltage test apparatus according to claim 1, wherein: the step-up transformer (1) is a transformer with adjustable output voltage.