阅读说明：本技术 一种基于信号差异性的输电线路故障类型判断方法 (Power transmission line fault type judgment method based on signal difference ) 是由 杨明 束小虎 王帅 朱成军 周新惠 于 2019-10-25 设计创作，主要内容包括：本发明提供了一种基于信号差异性的输电线路故障类型判断方法,所述输电线路故障判断方法包括如下步骤：步骤(1)：采集输电线路相电压、并联电抗器电压、中性点小电抗电压；步骤(2)：判断所述输电线路是否发生接地故障,若发生接地故障,进入步骤(3)；若没有发生接地故障,返回步骤(1)；步骤(3)：计算固定时间内并联电抗器电压与中性点小电抗电压的差异性；步骤(4)：根据差异性判断接地故障类型；步骤(5)：检测结果进行显示；步骤(6)：将检测结果上传至智能电气设备和监控中心。本发明提供一种基于信号差异性的输电线路故障类型判断方法,根据信号的差异性,判断输电线路故障是瞬时性还是永久性。(the invention provides a power transmission line fault type judgment method based on signal difference, which comprises the following steps: step (1): collecting phase voltage, shunt reactor voltage and neutral point small reactance voltage of a power transmission line; step (2): judging whether the power transmission line has a ground fault, and if so, entering the step (3); if no ground fault occurs, returning to the step (1); and (3): calculating the difference between the voltage of the shunt reactor and the voltage of the neutral point small reactance in fixed time; and (4): judging the type of the ground fault according to the difference; and (5): displaying the detection result; and (6): and uploading the detection result to the intelligent electrical equipment and the monitoring center. The invention provides a method for judging the fault type of a power transmission line based on signal difference, which judges whether the fault of the power transmission line is transient or permanent according to the difference of signals.)

1. A power transmission line fault type judgment method based on signal difference is characterized by comprising the following steps:

Step (1): collecting phase voltage, shunt reactor voltage and neutral point small reactance voltage of the power transmission line;

step (2): judging whether the power transmission line has a ground fault according to the phase voltage, and entering the step (3) if the power transmission line has the ground fault; if no ground fault occurs, returning to the step (1);

And (3): calculating the difference between the voltage of the shunt reactor and the small reactance voltage of the neutral point in fixed timeT is fixed time after the breaker is disconnected, U₁(t) is the shunt reactor voltage at time t within the fixed time, U₂(t) is the neutral point small reactance voltage at the time t within the fixed time;

And (4): judging the type of the ground fault: judging whether the difference K is larger than a difference reference value K or not_sIf it is greater than the difference reference value K_sThen it is a transient fault; if not greater than the difference reference value K_sIf the fault is a permanent fault;

and (5): displaying the fault detection result of the power transmission line through display equipment;

and (6): and uploading the detection result of the transmission line fault to intelligent electrical equipment and a monitoring center through a communication module, and taking a solution in time.

2. The method for judging the type of the power transmission line fault based on the signal difference as claimed in claim 1, wherein the method for judging the power transmission line fault is written into a microprocessor, and the collected signals are intelligently analyzed and judged to realize intelligent monitoring of the power transmission line fault.

3. The method for judging the fault type of the power transmission line based on the signal difference as claimed in claim 2, wherein the phase voltage, the shunt reactor voltage and the neutral point small reactance voltage of the power transmission line are acquired by a voltage sensor and transmitted to the microprocessor for analysis and judgment.

4. the method according to claim 3, wherein the microprocessor compares the phase voltages with phase voltage reference values, and if one phase voltage is smaller than a first phase voltage reference value and the other phase voltage is larger than a second phase voltage reference value, the power transmission line has a ground fault; the first phase voltage reference is less than a phase voltage rating and the second phase voltage reference is greater than the phase voltage rating.

5. The method according to claim 4, wherein the communication module uploads the transmission line fault detection result to the intelligent electrical device and the monitoring center by using a wireless communication device.

Technical Field

The invention belongs to the technical field of power detection, and particularly relates to a power transmission line fault type judgment method based on signal difference.

Background

With the continuous development of science and technology, the electric power scale of China is rapidly expanded, and the requirements of people on the quality of electric energy are higher and higher, especially on the aspects of the safety, reliability and stability of a system. The transmission line is used as an important component of an electric power system, has the widest coverage and severe working environment, and is easily influenced by various natural factors, so that short-circuit faults occur.

When short-circuit fault occurs on a transmission line, the two types of faults can be classified according to different characteristics of the faults: transient faults, permanent faults. Transient faults generally refer to that when a short-circuit fault occurs in a circuit, a protection device can act rapidly to remove the fault, an electric arc can be extinguished rapidly, the insulation level at the fault point can be recovered, and after a breaker is switched on, a system can recover power supply normally. Permanent faults are those in which, when a line fails, the insulation level is generally unrecoverable, and the fault point always exists, and if the breaker is reclosed, the equipment of the power system is subjected to the impact of short-circuit current again. Therefore, the invention provides a method for judging the fault type of the power transmission line based on the signal difference, which judges whether the fault of the power transmission line is instantaneous or permanent according to the signal difference, so that the fault processing is carried out more safely, and the safety and the reliability of the power transmission line are ensured.

Disclosure of Invention

The invention provides a power transmission line fault type judging method based on signal difference, which judges whether the power transmission line fault is transient or permanent according to the signal difference, and further carries out fault processing more safely.

The invention specifically relates to a power transmission line fault type judgment method based on signal difference, which comprises the following steps:

Step (1): collecting phase voltage, shunt reactor voltage and neutral point small reactance voltage of the power transmission line;

Step (2): judging whether the power transmission line has a ground fault according to the phase voltage, and entering the step (3) if the power transmission line has the ground fault; if no ground fault occurs, returning to the step (1);

And (3): calculating the difference between the voltage of the shunt reactor and the small reactance voltage of the neutral point in fixed timeT is fixed time after the breaker is disconnected, U₁(t) is the shunt reactor voltage at time t within the fixed time, U₂(t) is the neutral point small reactance voltage at the time t within the fixed time;

and (4): judging the type of the ground fault: judging whether the difference K is larger than a difference reference value K or not_sIf it is greater than the difference reference value K_sThen it is a transient fault; if not greater than the difference reference value K_sIf the fault is a permanent fault;

And (5): displaying the fault detection result of the power transmission line through display equipment;

And (6): and uploading the detection result of the transmission line fault to intelligent electrical equipment and a monitoring center through a communication module, and taking a solution in time.

and writing the power transmission line fault judgment method into a microprocessor, and intelligently analyzing and judging the acquired signals to realize intelligent monitoring of the power transmission line fault.

And the phase voltage of the power transmission line, the voltage of the shunt reactor and the small reactance voltage of the neutral point adopt a voltage sensor to carry out signal acquisition and transmit the signals to the microprocessor for analysis and judgment.

The microprocessor compares the phase voltage with a phase voltage reference value, and if the phase voltage of one phase is smaller than the first phase voltage reference value and the phase voltage of the other phase is larger than the second phase voltage reference value, the power transmission line has a ground fault; the first phase voltage reference is less than a phase voltage rating and the second phase voltage reference is greater than the phase voltage rating.

And the communication module uploads the transmission line fault detection result to the intelligent electrical equipment and the monitoring center by adopting wireless communication equipment.

Compared with the prior art, the beneficial effects are: according to the method for judging the transmission line fault, whether the transmission line fault is transient or permanent is judged according to the difference between the voltage of the shunt reactor and the small reactance voltage of the neutral point, so that the fault processing is carried out more safely, and the safety and the reliability of the transmission line are ensured.

Drawings

Fig. 1 is a working flow chart of a method for judging a fault type of a power transmission line based on signal difference according to the present invention.

Detailed Description

The following describes in detail a specific embodiment of the method for determining a fault type of a power transmission line based on signal differences according to the present invention with reference to the accompanying drawings.

As shown in fig. 1, the method for determining a fault of a power transmission line of the present invention includes the following steps:

step (1): collecting phase voltage, shunt reactor voltage and neutral point small reactance voltage of the power transmission line;

Step (2): judging whether the power transmission line has a ground fault according to the phase voltage, and entering the step (3) if the power transmission line has the ground fault; if no ground fault occurs, returning to the step (1);

And (3): calculating the voltage of the shunt reactor and the neutral point small current in fixed timedifference in resistance to voltaget is fixed time after the breaker is disconnected, U₁(t) is the shunt reactor voltage at time t within the fixed time, U₂(t) is the neutral point small reactance voltage at the time t within the fixed time;

and (4): judging the type of the ground fault: judging whether the difference K is larger than a difference reference value K or not_sIf it is greater than the difference reference value K_sThen it is a transient fault; if not greater than the difference reference value K_sIf the fault is a permanent fault;

and (5): displaying the fault detection result of the power transmission line through display equipment;

And (6): and uploading the detection result of the transmission line fault to intelligent electrical equipment and a monitoring center through a communication module, and taking a solution in time.

And writing the power transmission line fault judgment method into a microprocessor, and intelligently analyzing and judging the acquired signals to realize intelligent monitoring of the power transmission line fault.

And the phase voltage of the power transmission line, the voltage of the shunt reactor and the small reactance voltage of the neutral point adopt a voltage sensor to carry out signal acquisition and transmit the signals to the microprocessor for analysis and judgment.

and the fixed time T is 500ms after the breaker is disconnected.

the microprocessor compares the phase voltage with a phase voltage reference value, and if the phase voltage of one phase is smaller than the first phase voltage reference value and the phase voltage of the other phase is larger than the second phase voltage reference value, the power transmission line has a ground fault; the first phase voltage reference value is less than a phase voltage nominal value, and the second phase voltage reference value is greater than a phase voltage nominal value; the first phase voltage reference value is 0.1 time of a phase voltage rated value; the second phase voltage reference value is 1.5 times the phase voltage rated value.

and the communication module uploads the detection result of the power transmission line fault to the intelligent electrical equipment and the monitoring center by adopting wireless communication equipment, and then, measures are taken in time.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the same. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.