CN108548997B - Transformer substation space partial discharge positioning method and system - Google Patents

Abstract

The invention discloses a method for localizing partial discharge in substation space, which comprises the steps of: (1) selecting N measurement points in a measured area, and constructing a probability distribution characteristic matrix Ψ ^(m) of simulated partial discharge signal strength; (2) when partial discharge When it actually occurs, q UHF sensors are used to collect the partial discharge signal and obtain the measured partial discharge intensity characteristic vector.

(3) Obtain the localization result E of partial discharge based on the model formula. In addition, the invention also discloses a substation space partial discharge positioning system, comprising: q ultra-high frequency sensors and a processing unit connected with the q ultra-high frequency sensors for data. The spatial partial discharge positioning method of the substation can locate quickly, and is less affected by the space environment and electromagnetic environment, which reduces the difficulty of partial discharge monitoring in the substation, improves the maintenance efficiency of power equipment faults, and further improves the intelligent level of the operation and maintenance of the substation.

Description

Method and system for localization of partial discharge in substation space

technical field

The present invention relates to a positioning method and system, in particular to a positioning method and system for partial discharge signals.

Background technique

The live detection of power equipment is one of the important means to discover hidden dangers in the operation of power equipment, and it is also an important guarantee for the safe and stable operation of power equipment. According to statistics, with the continuous improvement of the voltage level of my country's power system, insulation faults account for more than 50% of power equipment faults. An important manifestation of equipment insulation failure is the occurrence of partial discharge. Partial discharge is not only a manifestation of insulation degradation, but also aggravates the degree of insulation degradation, resulting in a vicious circle, which eventually leads to insulation breakdown, which in turn leads to major accidents. Effective partial discharge detection and positioning technology can detect insulation faults in time and accurately locate them, speed up maintenance speed and efficiency, and avoid the spread of accidents. Therefore, the detection and localization of partial discharge has become the focus of live detection work.

If the monitoring and investigation of every power equipment in the whole station space of the substation is adopted, the equipment and labor costs will be greatly increased, and the monitoring efficiency will be extremely low. At present, there are mainly two types of UHF partial discharge localization technologies used in the whole station space of substations: time difference method and angle location method. Among them, the time difference method needs to sample the signal at a high sampling frequency, so this method has high requirements on hardware and is difficult to implement; the angle positioning method is easily affected by the space environment and the electromagnetic environment, and it is difficult to be accurate in practical applications. position.

Based on this, it is expected to obtain a partial discharge localization method for the entire substation space. When partial discharge occurs, the partial discharge localization method can quickly locate the faulty equipment, greatly improve the detection and localization efficiency of partial discharge, and significantly reduce the equipment. ,Labor costs. In addition, the partial discharge localization method is less affected by the space environment and electromagnetic environment, which reduces the difficulty of partial discharge monitoring in substations, improves the maintenance efficiency of power equipment faults, and finally improves the intelligent level of substation operation and maintenance.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a localization method for partial discharge in substation space. The method for localization of partial discharge in substation space is based on the constructed simulated partial discharge signal intensity probability distribution characteristics, and then uses Bayesian probability method to determine the occurrence of partial discharge in each area. probability, and finally realize the spatial localization of partial discharge through comprehensive analysis. The spatial partial discharge positioning method of the substation can locate quickly, and is less affected by the space environment and electromagnetic environment, which reduces the difficulty of partial discharge monitoring in the substation, improves the maintenance efficiency of power equipment faults, and further improves the intelligent level of the operation and maintenance of the substation.

Based on the above purpose, the present invention proposes a method for localizing partial discharge in a substation space, which includes the steps:

(1) N measurement points are selected in the tested area, and the simulated partial discharge signal intensity probability distribution characteristic matrix Ψ ^{(m) is} constructed;

(2) When the partial discharge actually occurs, use q UHF sensors to collect the partial discharge signal and obtain the measured partial discharge intensity characteristic vector

(3) Obtain the partial discharge localization result E based on the following model formula:

表示选取自模拟局部放电信号强度概率分布特性矩阵Ψ^(m)中的第k列的向量，

表示选取自模拟局部放电信号强度概率分布特性矩阵Ψ^(m)中的第n列的向量。Among them, _Sk represents the coordinates of the measurement point RP _k , k represents one of the N measurement points; _Sn represents the coordinates of the measurement point RP _n , n=1,2,...,N; d represents r _PD The dimensions of , μ _k and μ _n represent the sample mean values of PD signal intensity at measurement points RP _k and RP _n , respectively, C _k and C _n are covariance matrices,

represents the vector selected from the kth column in the probability distribution characteristic matrix Ψ ^(m) of the simulated partial discharge signal strength,

Represents a vector selected from the nth column of the simulated partial discharge signal strength probability distribution characteristic matrix Ψ ^(m) .

It should be noted that T represents the transpose of a vector, which is a common symbol in the field.

Further, in the method for localizing partial discharge in substation space according to the present invention, step (1) further comprises the steps of:

则测量点RP_j处的模拟局部放电强度特性向量r^(m) _j为：Denote the measurement points in the measured area as RP _j (j=1,2,...,N), use the simulated partial discharge source to discharge M times at each measurement point, and use q UHF sensors to measure each measurement point For each simulated partial discharge signal intensity, record any UHF sensor as AP _i (i=1, 2, 3, 4..., q); set the measurement point RP _j measured by the UHF sensor AP _i The simulated partial discharge intensity value at

Then the simulated partial discharge intensity characteristic vector r ^(m) _j at the measurement point RP _j is:

其中m表示测量次数，m＝1,2,…,M；

Where m represents the number of measurements, m=1,2,...,M;

Then the simulated partial discharge intensity characteristic vectors of all measurement points constitute the simulated partial discharge signal intensity probability distribution characteristic matrix Ψ ^(m) of the measured area:

Further, in the method for localizing partial discharge in substation space according to the present invention, the q UHF sensors are set as 4 UHF sensors.

Further, in the method for localizing partial discharge in substation space according to the present invention, the UHF sensor is a UHF wireless sensor.

It should be noted that, in order to facilitate data transmission and transmission, UHF wireless sensors are preferably used in this case.

Correspondingly, another object of the present invention is to provide a localization system for partial discharge in substation space. The localization system for partial discharge in substation space is fast in positioning, less affected by space environment and electromagnetic environment, and reduces the difficulty of partial discharge monitoring in substations. It improves the maintenance efficiency of power equipment failures, thereby improving the intelligent level of substation operation and maintenance.

Based on the above purpose, the present invention also proposes a substation spatial partial discharge positioning system, including: q UHF sensors and a processing unit connected to the q UHF sensors for data; wherein:

The processing unit constructs a probability distribution characteristic matrix Ψ ^(m) of the simulated partial discharge signal intensity based on the simulated partial discharge signals transmitted by the q UHF sensors;

When partial discharge actually occurs, q UHF sensors are used to collect partial discharge signals, and the processing unit obtains the measured partial discharge intensity characteristic vector based on these partial discharge signals

The processing unit obtains the partial discharge localization result E based on the following model formula:

表示选取自模拟局部放电信号强度概率分布特性矩阵Ψ^(m)中的第k列的向量，

表示选取自模拟局部放电信号强度概率分布特性矩阵Ψ^(m)中的第n列的向量。Among them, _Sk represents the coordinates of the measurement point RP _k , k represents one of the N measurement points; _Sn represents the coordinates of the measurement point RP _n , n=1,2,...,N; d represents r _PD The dimensions of , μ _k and μ _n represent the sample mean values of PD signal intensity at measurement points RP _k and RP _n , respectively, C _k and C _n are covariance matrices,

represents the vector selected from the kth column in the probability distribution characteristic matrix Ψ ^(m) of the simulated partial discharge signal strength,

Represents a vector selected from the nth column of the simulated partial discharge signal strength probability distribution characteristic matrix Ψ ^(m) .

Further, in the substation space partial discharge positioning system of the present invention, the processing unit constructs the simulated partial discharge signal intensity probability distribution characteristic matrix Ψ ^(m) based on the simulated partial discharge signals transmitted by the q UHF sensors, including the steps of: :

则测量点RP_j处的模拟局部放电强度特性向量r^(m) _j为：Denote the measurement points in the measured area as RP _j (j=1,2,...,N), use the simulated partial discharge source to discharge M times at each measurement point, and use q UHF sensors to measure each measurement point For each simulated partial discharge signal intensity, record any UHF sensor as AP _i (i=1, 2, 3, 4..., q); set the measurement point RP _j measured by the UHF sensor AP _i The simulated partial discharge intensity value at

Then the simulated partial discharge intensity characteristic vector r ^(m) _j at the measurement point RP _j is:

其中m表示测量次数，m＝1,2,…,M；

Where m represents the number of measurements, m=1,2,...,M;

Then the simulated partial discharge intensity characteristic vectors of all measurement points constitute the simulated partial discharge signal intensity probability distribution characteristic matrix Ψ ^(m) of the measured area:

Further, in the substation space partial discharge positioning system according to the present invention, the q UHF sensors are set as 4 UHF sensors.

Further, in the substation space partial discharge positioning system of the present invention, the UHF sensor is a UHF wireless sensor.

It should be noted that, in order to facilitate data transmission and transmission, UHF wireless sensors are preferably used in this case.

Further, in the substation space partial discharge positioning system of the present invention, a router is connected between the UHF sensor and the processing unit.

The partial discharge localization method in the substation space of the present invention is based on the constructed simulated partial discharge signal intensity probability distribution characteristics, and then judges the probability of partial discharge occurring in each area through the Bayesian probability method, and finally realizes the partial discharge space through comprehensive analysis. position. The method for localizing partial discharge in space of a substation can locate quickly, and is less affected by the space environment and electromagnetic environment, which reduces the difficulty of monitoring partial discharge in the substation, improves the maintenance efficiency of power equipment faults, and further improves the intelligent operation and maintenance of the substation. Level.

In addition, the substation space partial discharge positioning system of the present invention also has the above advantages.

Description of drawings

FIG. 1 is a schematic flowchart of the method for localizing partial discharge in a substation space according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of the substation space partial discharge positioning system according to an embodiment of the present invention.

FIG. 3 shows the arrangement of the substation space partial discharge positioning system according to the present invention in one embodiment.

Detailed ways

The substation space partial discharge location and system of the present invention will be further explained and described below in conjunction with the drawings and specific embodiments of the description, but the explanation and explanation do not constitute an improper limitation of the technical solution of the present invention.

FIG. 1 is a schematic flowchart of the method for localizing partial discharge in a substation space according to an embodiment of the present invention.

As shown in FIG. 1 , the localization of partial discharge in the substation space in this embodiment includes the steps:

则测量点RP_j处的模拟局部放电强度特性向量r^(m) _j为：(1) Select N measurement points in the measured area, and construct a probability distribution characteristic matrix Ψ ^(m) of simulated partial discharge signal strength, where the measurement points in the measured area are recorded as RP _j (j=1,2, ...,N), use the analog partial discharge source to discharge M times at each measurement point, use q UHF sensors to measure the simulated partial discharge signal strength of each measurement point, and record any UHF sensor as AP _i (i=1, 2, 3, 4..., q); set the simulated partial discharge intensity at the measurement point RP _j measured by the UHF sensor AP _i as

Then the simulated partial discharge intensity characteristic vector r ^(m) _j at the measurement point RP _j is:

其中m表示测量次数，m＝1,2,…,M；需要说明的是，其中T表示向量的转置，为本领域内的通用符号。

where m represents the number of measurements, m=1, 2, .

Then the simulated partial discharge intensity characteristic vectors of all measurement points constitute the simulated partial discharge signal intensity probability distribution characteristic matrix Ψ ^(m) of the measured area:

(2) When the partial discharge actually occurs, use q UHF sensors to collect the partial discharge signal and obtain the measured partial discharge intensity characteristic vector

(3) Obtain the partial discharge localization result E based on the following model formula:

表示选取自模拟局部放电信号强度概率分布特性矩阵Ψ^(m)中的第k列的向量，

表示选取自模拟局部放电信号强度概率分布特性矩阵Ψ^(m)中的第n列的向量。Among them, _Sk represents the coordinates of the measurement point RP _k , k represents one of the N measurement points; _Sn represents the coordinates of the measurement point RP _n , n=1,2,...,N; d represents r _PD The dimensions of , μ _k and μ _n represent the sample mean values of PD signal intensity at measurement points RP _k and RP _n , respectively, C _k and C _n are covariance matrices,

represents the vector selected from the kth column in the probability distribution characteristic matrix Ψ ^(m) of the simulated partial discharge signal strength,

Represents a vector selected from the nth column of the simulated partial discharge signal strength probability distribution characteristic matrix Ψ ^(m) .

It should be noted that, in this embodiment, the q UHF sensors are set as four UHF sensors AP ₁ , AP ₂ , AP ₃ , and AP ₄ , and the UHF sensors AP ₁ , AP ₂ , and AP ₃ and AP ₄ are UHF wireless sensors.

FIG. 2 is a schematic diagram of the substation space partial discharge positioning system according to an embodiment of the present invention.

As shown in FIG. 2 , the spatial partial discharge localization system in the substation in this embodiment includes q ultra-high frequency sensors (in this embodiment, q=4, that is, the ultra-high frequency sensors AP ₁ , AP ₂ , AP ₃ and AP ₄ , each UHF sensor is a UHF wireless sensor) and a processing unit 1 that is data-connected to each UHF sensor, and the processing unit 1 realizes data connection through the router 2 .

The UHF sensors AP ₁ , AP ₂ , AP ₃ and AP ₄ are located at the four corners of the test area 4 respectively. When a partial discharge occurs at a certain place P in the test area, the UHF sensors AP ₁ , AP ₂ , AP ₃ and AP ₄ collect partial discharge signals.

The specific process is shown in Figure 3. FIG. 3 shows the arrangement of the substation space partial discharge positioning system according to the present invention in one embodiment.

During the test, the test area 4 is within a square area of 24m*24m (L1 in the figure represents the side length of the square area, L1=24m), and four UHF sensors AP ₁ , AP ₂ , For AP ₃ and AP ₄ , in order to express the orientation, a plane rectangular coordinate system is established. The coordinates of AP ₃ in the coordinate system are (1,1), the coordinates of AP ₄ in the coordinate system are (25, 1), and the coordinates of AP ₁ are The coordinates in the coordinate system are (25, 25), the coordinates of AP ₂ in the coordinate system are (1, 25), and there are 625 test points evenly distributed in the square area, along the X-axis direction or the direction of a straight line parallel to it The interval L2 between the two adjacent test points above is 1m, and the interval L3 between the two adjacent test points along the Y-axis direction or a straight line parallel thereto is also 1m.

则测量点RP_j处的模拟局部放电强度特性向量r^(m) _j为：

其中m表示测量次数，m＝1,2,…,M；需要说明的是，其中T表示向量的转置，为本领域内的通用符号。Denote the measurement points in the measured area as RP _j (j=1,2,...,N, in this embodiment N=625), use the simulated partial discharge source to discharge M times at each measurement point, and use A UHF sensor measures the simulated partial discharge signal intensity of each measurement point, and any UHF sensor is recorded as AP _i (i=1, 2, 3, 4..., q); set the UHF sensor The simulated partial discharge intensity at measurement point RP _j measured by AP _i is

Then the simulated partial discharge intensity characteristic vector r ^(m) _j at the measurement point RP _j is:

where m represents the number of measurements, m=1, 2, .

Then the simulated partial discharge intensity characteristic vectors of all measurement points constitute the simulated partial discharge signal intensity probability distribution characteristic matrix Ψ ^(m) of the measured area:

The processing unit 1 constructs an analog partial discharge signal intensity probability distribution characteristic matrix Ψ ^(m) based on the analog partial discharge signals transmitted by the UHF sensors AP ₁ , AP ₂ , AP ₃ and AP ₄ ;

When partial discharge actually occurs, the UHF sensors AP ₁ , AP ₂ , AP ₃ and AP ₄ are used to collect partial discharge signals, and the processing unit 1 obtains the measured partial discharge intensity characteristic vector based on these partial discharge signals

The processing unit 1 obtains the partial discharge localization result E based on the following model formula:

表示选取自模拟局部放电信号强度概率分布特性矩阵Ψ^(m)中的第k列的向量，

表示选取自模拟局部放电信号强度概率分布特性矩阵Ψ^(m)中的第n列的向量。Among them, _Sk represents the coordinates of the measurement point RP _k , k represents one of the N measurement points; _Sn represents the coordinates of the measurement point RP _n , n=1,2,...,N; d represents r _PD The dimensions of , μ _k and μ _n represent the sample mean values of PD signal intensity at measurement points RP _k and RP _n , respectively, C _k and C _n are covariance matrices,

represents the vector selected from the kth column in the probability distribution characteristic matrix Ψ ^(m) of the simulated partial discharge signal strength,

Represents a vector selected from the nth column of the simulated partial discharge signal strength probability distribution characteristic matrix Ψ ^(m) .

In order to verify the localization effect of substation space partial discharge based on Bayesian probability, each test point in the test area is measured by the substation space partial discharge localization method of this case, the time difference method and the angle localization method of the prior art. The error statistics between the values obtained by the measurement and the coordinate data of the actual occurrence of partial discharge are carried out, and the results are shown in Table 1.

Table 1.

Localization method of partial discharge in substation space time difference Angle positioning method Average positioning error (m) 1.86 2.38 2.84 Error less than 1m percentage (%) 32.3 24.2 21.0 The error is less than 3m percentage (%) 75.2 70.2 64.2 The error is less than 5m percentage (%) 87.5 84.6 83.5 Maximum error (m) 8.25 11.23 11.78

It can be seen from Table 1 that the average positioning error of the substation-wide partial discharge positioning method in this case is 1.86 meters, and the percentage of the positioning error less than 3 meters is 75.2%. The performance is significantly better than the existing technology. And the positioning error of 1.86 meters fully meets the accuracy requirements of partial discharge positioning in substations. This shows that based on the probability distribution characteristics of the simulated partial discharge signal intensity, the probability of partial discharge occurring in each area is judged by the Bayesian probability method, and the spatial positioning of partial discharge is finally realized through comprehensive analysis. The spatial partial discharge positioning method of the substation can locate quickly, and is less affected by the space environment and electromagnetic environment, which reduces the difficulty of partial discharge monitoring in the substation, improves the maintenance efficiency of power equipment faults, and further improves the intelligent level of the operation and maintenance of the substation.

Moreover, compared with the time difference method and the angle positioning method in the prior art, this case only needs to measure the partial discharge signal strength information, which not only ensures high positioning accuracy, but also significantly reduces the cost of system hardware and effectively improves the power of the substation. The monitoring and maintenance efficiency of equipment has good practical application value.

It should be noted that the prior art part in the protection scope of the present invention is not limited to the examples given in this application document, and all prior art that does not contradict the solution of the present invention, including but not limited to the prior art Patent documents, prior publications, prior publications, etc., can all be included in the protection scope of the present invention.

In addition, the combination of the technical features in this case is not limited to the combination described in the claims of this case or the combination described in the specific embodiments, and all the technical features described in this case can be freely combined or combined in any way, unless conflict with each other.

It should also be noted that the above-listed embodiments are only specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments, and the similar changes or deformations made subsequently can be directly derived from the contents disclosed in the present invention or can be easily thought of by those skilled in the art, and all belong to the protection scope of the present invention. .

Claims (9)

1. A method for localizing partial discharge in substation space, comprising the steps of: (1) N measurement points are selected in the tested area, and the simulated partial discharge signal intensity probability distribution characteristic matrix Ψ ^{(m) is} constructed; (2) When the partial discharge actually occurs, use q UHF sensors to collect the partial discharge signal and obtain the measured partial discharge intensity characteristic vector

(3) Obtain the partial discharge localization result E based on the following model formula:

Among them, _Sk represents the coordinates of the measurement point RP _k , k represents one of the N measurement points; _Sn represents the coordinates of the measurement point RP _n , n=1,2,...,N; d represents r _PD The dimensions of , μ _k and μ _n represent the sample mean values of PD signal intensity at measurement points RP _k and RP _n , respectively, C _k and C _n are covariance matrices,

represents the vector selected from the kth column in the probability distribution characteristic matrix Ψ ^(m) of the simulated partial discharge signal strength,

Represents a vector selected from the nth column in the probability distribution characteristic matrix of simulated partial discharge signal strength Ψ ^(m) , where m represents the number of measurements, m=1, 2,...,M. 2. The method for locating partial discharge in substation space as claimed in claim 1, wherein step (1) further comprises the steps of: Denote the measurement points in the measured area as RP _j (j=1,2,...,N), use the simulated partial discharge source to discharge M times at each measurement point, and use q UHF sensors to measure each measurement point For each simulated partial discharge signal intensity, record any UHF sensor as AP _i (i=1, 2, 3, 4..., q); set the measurement point RP _j measured by the UHF sensor AP _i The simulated partial discharge intensity value at

Then the simulated partial discharge intensity characteristic vector r ^(m) _j at the measurement point RP _j is:

Where m represents the number of measurements, m=1,2,...,M; Then the simulated partial discharge intensity characteristic vectors of all measurement points constitute the simulated partial discharge signal intensity probability distribution characteristic matrix Ψ ^(m) of the measured area:

3 . The method for localizing partial discharge in substation space according to claim 1 , wherein the q UHF sensors are set as 4 UHF sensors. 4 . 4 . The method for localizing partial discharge in substation space according to claim 1 , wherein the UHF sensor is an UHF wireless sensor. 5 . 5. A spatial partial discharge positioning system in a substation, comprising: q UHF sensors and a processing unit data-connected to the q UHF sensors; wherein: The processing unit constructs a probability distribution characteristic matrix Ψ ^(m) of the simulated partial discharge signal intensity based on the simulated partial discharge signals transmitted by the q UHF sensors; When partial discharge actually occurs, q UHF sensors are used to collect partial discharge signals, and the processing unit obtains the measured partial discharge intensity characteristic vector based on these partial discharge signals

The processing unit obtains the partial discharge localization result E based on the following model formula:

Among them, _Sk represents the coordinates of the measurement point RP _k , k represents one of the N measurement points; _Sn represents the coordinates of the measurement point RP _n , n=1,2,...,N; d represents r _PD The dimensions of , μ _k and μ _n represent the sample mean values of PD signal intensity at measurement points RP _k and RP _n , respectively, C _k and C _n are covariance matrices,

represents the vector selected from the kth column in the probability distribution characteristic matrix Ψ ^(m) of the simulated partial discharge signal strength,

Represents a vector selected from the nth column in the probability distribution characteristic matrix of simulated partial discharge signal strength Ψ ^(m) , where m represents the number of measurements, m=1, 2,...,M. 6. The partial discharge positioning system in substation space as claimed in claim 5, wherein the processing unit constructs a simulated partial discharge signal intensity probability distribution characteristic matrix Ψ ^{(m )} includes steps: Denote the measurement points in the measured area as RP _j (j=1,2,...,N), use the simulated partial discharge source to discharge M times at each measurement point, and use q UHF sensors to measure each measurement point For each simulated partial discharge signal intensity, record any UHF sensor as AP _i (i=1, 2, 3, 4..., q); set the measurement point RP _j measured by the UHF sensor AP _i The simulated partial discharge intensity value at

Then the simulated partial discharge intensity characteristic vector r ^(m) _j at the measurement point RP _j is:

Where m represents the number of measurements, m=1,2,...,M; Then the simulated partial discharge intensity characteristic vectors of all measurement points constitute the simulated partial discharge signal intensity probability distribution characteristic matrix Ψ ^(m) of the measured area:

7 . The partial discharge localization system in substation space according to claim 5 , wherein the q UHF sensors are set as 4 UHF sensors. 8 . 8 . The partial discharge positioning system in substation space according to claim 5 , wherein the UHF sensor is a UHF wireless sensor. 9 . 9 . The partial discharge positioning system in substation space according to claim 5 , wherein a router is connected between the UHF sensor and the processing unit. 10 .

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