CN104569769A - Power cable partial discharge simulation system and testing method - Google Patents

Abstract

The invention discloses a power cable partial discharge simulation system and a testing method. The system includes a pulse generation unit, a measurement unit, a pulse detection unit and a pulse wave responder, the control output end of the measurement unit and the excitation pulse control input end of the pulse generation unit The excitation pulse output end of the pulse generating unit is connected to the near end of the power cable through the first high frequency current transformer, and the input end of the measurement unit is connected to the near end of the power cable through the second high frequency current transformer. The input end of the pulse detection unit is connected to the far end of the power cable through the third high-frequency current transformer, the output end of the pulse detection unit is connected to the pulse wave responder, and the pulse wave responder is connected to the power cable through the fourth high-frequency current transformer. The remote ends of the power cables are connected. The invention accurately detects the position of the partial discharge signal, detects the fault of the cable in advance, so as to prevent it, has strong anti-interference performance, and has a good application prospect.

Description

A power cable partial discharge simulation system and testing method

technical field

The invention relates to a power cable partial discharge simulation system and a test method, belonging to the technical field of power equipment detection.

Background technique

With the development of my country's modernization and the continuous progress of science and technology, my country's research, manufacture and application of cables have developed rapidly. From power stations to urban and rural power grids, from power distribution stations to factory streets, cable lines have been more and more widely used due to their unique characteristics, and their number has doubled, playing an irreplaceable role in many occasions. . In such a huge and complex cable network, due to many factors such as cable production quality, improper construction, and poor operation and maintenance, cable failures will occur. Ensuring the normal operation of cables is the focus of ensuring reliable power supply, and insulation aging accounts for a large part. Therefore, the cable insulation is one of the important means to ensure reliable power supply. The best way is that we can make judgments in advance, prevent in advance, and eliminate faults in advance. At present, the main method is to detect and locate through the method of power failure pre-test. Since this method requires a power outage, it will bring certain economic losses. If we can evaluate the working status of the cable in time, find out the fault of the cable in advance, and judge the cause and location of the fault while live, we can make preventive measures in advance. , to prevent the occurrence of vicious accidents, however, there are many strong electromagnetic field interference sources where the cable is working, the data acquisition accuracy is not high, the original waveform of the collected signal is seriously distorted, and it is easy to mislead, misjudgment, or even miss the judgment. How to improve the safety of the cable? The accuracy of work status assessment is an urgent problem to be solved.

Contents of the invention

The purpose of the present invention is to overcome the problem of how to improve the accuracy of the evaluation of the working state of the cable due to the need for a power failure for detection and positioning through the existing method of power failure pretest, which will bring certain economic losses. The power cable partial discharge simulation system and testing method of the present invention can capture the partial discharge signal on the power cable in operation, accurately detect the position of the partial discharge signal, discover the fault of the cable in advance, take precautions, and prevent the occurrence of malignant accidents. It has strong anti-interference performance and has good application prospects.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A power cable partial discharge simulation system is characterized in that it includes a pulse generation unit, a measurement unit, a pulse detection unit and a pulse wave transponder,

The pulse generating unit is arranged at the near end of the power cable, and is used to inject excitation pulses to the near end of the power cable through coupling;

The measuring unit is arranged at the near end of the power cable, and is used for measuring and analyzing the pulse location of the partial discharge of the power cable, and controlling the pulse generating unit to send an excitation pulse;

The pulse detection unit is arranged at the far end of the power cable, and is used to receive the excitation pulse sent by the pulse generation unit and notify the pulse transponder;

The pulse transponder is arranged at the far end of the power cable, and is used to inject echo pulses to the far end of the power cable through coupling;

The control output end of the measurement unit is connected to the excitation pulse control input end of the pulse generation unit, and the excitation pulse output end of the pulse generation unit is connected to the near end of the power cable through the first high-frequency current transformer. The input end of the measurement unit is connected to the near end of the power cable through the second high-frequency current transformer, and the input end of the pulse detection unit is connected to the far end of the power cable through the third high-frequency current transformer. The output end of the detection unit is connected to the pulse wave responder, and the pulse wave responder is connected to the far end of the power cable through the fourth high-frequency current transformer.

The aforementioned power cable partial discharge simulation system is characterized in that: the measurement unit is also connected with a power frequency synchronizer.

The aforementioned power cable partial discharge simulation system is characterized in that: the first high-frequency current transformer, the second high-frequency current transformer, the third high-frequency current transformer, and the fourth high-frequency current transformer are shielded Type high-frequency current transformer, and socketed on the power cable.

Based on the test method of the above-mentioned power cable partial discharge simulation system, it is characterized in that: comprising the following steps,

Step (1), the pulse generating unit is controlled by the measurement unit to send an excitation pulse, and the excitation pulse is transmitted to the near end and the far end of the power cable;

Step (2), the measurement unit receives the excitation pulse at the near end of the power cable, the pulse detection unit receives the excitation pulse at the far end of the power cable, and the pulse detection unit triggers the pulse transponder to send an echo pulse to feed back to the measuring unit;

Step (3), the measuring unit calculates the length of the power cable through the arrival time of the excitation pulse and the echo pulse;

Step (4), when the partial discharge pulse occurs on the power cable, the measurement unit captures the time when the partial discharge pulse first arrives, the feedback time for the partial discharge pulse to send the feedback signal to the measurement unit through the pulse detection unit and the pulse transponder;

Step (5), the measuring unit calculates the position of the partial discharge of the power cable through the first arrival time of the partial discharge pulse, the feedback time and the length of the power cable;

In step (6), the measurement unit performs characteristic map simulation through the received partial discharge pulse, and establishes a pulse database for identifying and judging the type of the partial discharge pulse.

The test method of the aforementioned power cable partial discharge simulation system is characterized in that: step (6), the measurement unit carries out characteristic map simulation by the partial discharge pulse received, and the process of setting up the pulse database is to pass the rise time of the partial discharge pulse, drop Time, pulse energy, peak value, pulse width and dead zone, carry out standard formatting, and establish a pulse database.

The beneficial effects of the present invention are: the power cable partial discharge simulation system and test method of the present invention include power cable length measurement, partial discharge location, partial discharge pulse, characteristic map simulation, identification and judgment of the type of partial discharge pulse, by capturing The partial discharge signal on the power cable in operation can accurately detect the position of the partial discharge signal, detect the fault of the cable in advance, take precautions, and prevent the occurrence of malignant accidents. It has strong anti-interference performance and has a good application prospect.

Description of drawings

Fig. 1 is a system block diagram of the power cable partial discharge simulation system of the present invention.

Fig. 2 is a flow chart of the measurement method of the power cable partial discharge simulation system of the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings. The following examples are only used to illustrate the technical solution of the present invention more clearly, but not to limit the protection scope of the present invention.

As shown in Figure 1, the power cable partial discharge simulation system of the present invention includes a pulse generation unit 1, a measurement unit 2, a pulse detection unit 3 and a pulse wave transponder 4,

The pulse generating unit 1 is arranged at the near end of the power cable, and is used to inject excitation pulses to the near end of the power cable through coupling, and a portable pulse generator can be used, which is convenient to carry;

The measuring unit 2 is arranged at the near end of the power cable, and is used for measuring and analyzing the pulse location of the partial discharge of the power cable, and controlling the pulse generating unit 1 to send an excitation pulse;

The pulse detection unit 3 is arranged at the far end of the power cable, for receiving the excitation pulse sent by the pulse generating unit 1, and notifying the pulse wave transponder 4;

The pulse wave transponder 4 is arranged at the far end of the power cable, and is used to inject echo pulses to the far end of the power cable through coupling, and a portable pulse generator can be used, which is convenient to carry;

The control output end of the measurement unit 2 is connected with the excitation pulse control input end of the pulse generation unit 1, and the excitation pulse output end of the pulse generation unit 1 is connected to the proximal end of the power cable through the first high-frequency current transformer 5. connected, the input end of the measurement unit 2 is connected to the near end of the power cable through the second high frequency current transformer 6, and the input end of the pulse detection unit 3 is connected to the power cable through the third high frequency current transformer 7 The remote end is connected, the output end of the pulse detection unit 3 is connected with the pulse wave transponder 4, and the pulse wave transponder 4 is connected with the far end of the power cable through the fourth high frequency current transformer 8, the first The high-frequency current transformer 5, the second high-frequency current transformer 6, the third high-frequency current transformer 7, and the fourth high-frequency current transformer 8 are shielded high-frequency current transformers, and are socketed on the power cable. Coupling the pulse signal, the measurement unit 2 is also connected with a power frequency synchronizer 9, the power frequency synchronizer 9 is used to generate a power frequency synchronization signal, and the synchronization of the excitation pulse sent by the pulse generation unit 1 is controlled by the measurement unit 2.

The test method based on the above-mentioned power cable partial discharge simulation system, as shown in Figure 2, comprises the following steps,

Step (1), the pulse generating unit 1 is controlled by the measuring unit 2 to send an excitation pulse, and the excitation pulse is propagated to the near end and the far end of the power cable;

Step (2), the measurement unit 2 receives the excitation pulse at the near end of the power cable, the pulse detection unit 3 receives the excitation pulse at the far end of the power cable, and the pulse detection unit 3 triggers the pulse transponder 4 to send an echo pulse after receiving the excitation pulse Feedback to the measurement unit 2;

Step (3), the measurement unit 2 calculates the length of the power cable by the arrival time of the excitation pulse and the echo pulse;

Step (4), when the partial discharge pulse occurs on the power cable, the measurement unit 2 captures the time when the partial discharge pulse first arrives, and the partial discharge pulse sends a feedback signal to the measurement unit 2 through the pulse detection unit 3 and the pulse wave transponder 4 Feedback time;

Step (5), the measuring unit 2 calculates the position of the partial discharge of the power cable through the first arrival time of the partial discharge pulse, the feedback time and the length of the power cable;

In step (6), the measurement unit 2 performs characteristic map simulation through the received partial discharge pulse, performs standard formatting through the rise time, fall time, pulse energy, peak value, pulse width and dead zone of the partial discharge pulse, and establishes a pulse database , as shown in Table 1 below, a pulse database table

Table 1 A pulse database table

non-local discharge Local PD noise Frequency Range 100‐4500kHz 4500‐10000kHz 0-100kHz rise/fall time 80-900ns 0-80ns 0 pulse width 2‐5us 0‐2us 0

Used to identify and judge the type of PD pulse, from the PD frequency range, rise, fall time and pulse width characteristic parameters to identify the type of PD, such as the frequency range is 4500-10000kHz, the rise and fall time is 0-80ns , the pulse width between 0‐2us is identified as a local PD pulse.

In summary, the power cable partial discharge simulation system and test method of the present invention include power cable length measurement, partial discharge location, partial discharge pulse, characteristic map simulation, identification and judgment of the type of partial discharge pulse, by capturing The partial discharge signal on the power cable can accurately detect the position of the partial discharge signal, detect the fault of the cable in advance, take precautions, and prevent the occurrence of malignant accidents. It has strong anti-interference performance and has a good application prospect. The basic principles, main features and advantages of the present invention have been shown and described above. Those skilled in the industry should understand that the present invention is not limited by the above-mentioned embodiments. What are described in the above-mentioned embodiments and the description only illustrate the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will also have Variations and improvements all fall within the scope of the claimed invention. The protection scope of the present invention is defined by the appended claims and their equivalents.

Claims (5)

1. a power cable shelf depreciation analogue system, is characterized in that: comprise impulse generating unit (1), measuring unit (2), pulse detection unit (3) and pulse wave transponder (4),

Described impulse generating unit (1) is arranged on the near-end of power cable, for through near-end from overcoupling to power cable inject driving pulse;

Described measuring unit (2) is arranged on the near-end of power cable, and for measuring, analyzing the pulse location of power cable shelf depreciation, and gating pulse generating unit (1) sends driving pulse;

Described pulse detection unit (3) is arranged on the far-end of power cable, for the driving pulse that received pulse generating unit (1) sends, and notifies pulse wave transponder (4);

Described pulse wave transponder (4) is arranged on the far-end of power cable, for through far-end from overcoupling to power cable inject echo-pulse;

The control output end of described measuring unit (2) is connected with the driving pulse control input end of impulse generating unit (1), the driving pulse output terminal of described impulse generating unit (1) is connected with the near-end of power cable by the first HF current transformer (5), the input end of described measuring unit (2) is connected with the near-end of power cable by the second HF current transformer (6), the input end of described pulse detection unit (3) is connected with the far-end of power cable by third high frequency current transformer (7), the output terminal of described pulse detection unit (3) is connected with pulse wave transponder (4), described pulse wave transponder (4) is connected with the far-end of power cable by the 4th HF current transformer (8).

2. a kind of power cable shelf depreciation analogue system according to claim 1, is characterized in that: described measuring unit (2) is also connected with power frequency synchronizer (9).

3. a kind of power cable shelf depreciation analogue system according to claim 1, it is characterized in that: described first HF current transformer (5), the second HF current transformer (6), third high frequently current transformer (7), the 4th HF current transformer (8) are protected type HF current transformer, and are socketed on power cable.

4., based on the method for testing of power cable shelf depreciation analogue system according to claim 1, it is characterized in that: comprise the following steps,

Step (1), sends driving pulse by measuring unit (2) gating pulse generating unit (1), and the described driving pulse in the same way near-end of power cable, far-end is propagated;

Step (2), measuring unit (2) receives driving pulse at the near-end of power cable, the far-end of pulse detection unit (3) power cable receives driving pulse, triggers pulse wave transponder (4) and send echo-pulse and feed back to measuring unit (2) after described pulse detection unit (3) receives driving pulse;

Step (3), measuring unit (2), by the time of arrival of driving pulse, echo-pulse, calculates the length of power cable;

Step (4), when power cable there is partial discharge pulse, the feedback time that measuring unit (2) catches time that partial discharge pulse reaches first, feedback signal is sent to measuring unit (2) by partial discharge pulse through pulse detection unit (3) and pulse wave transponder (4);

Step (5), the length of the time that measuring unit (2) is reached first by partial discharge pulse, feedback time and power cable, calculates the position of power cable shelf depreciation;

Step (6), measuring unit (2), by the partial discharge pulse received, carries out characteristic spectrum emulation, sets up pulse database, for identify and the type of pulse is put in judgement office.

5. the method for testing of power cable shelf depreciation analogue system according to claim 1, it is characterized in that: step (6), measuring unit (2), by the partial discharge pulse received, carries out characteristic spectrum emulation, and the process setting up pulse database is the rise time by partial discharge pulse, fall time, pulse energy, peak value, pulsewidth and dead band, carry out standard format, set up pulse database.