CN115879044A - CNN network-based GIS switching-on/off state current detection method and device - Google Patents

CNN network-based GIS switching-on/off state current detection method and device Download PDF

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CN115879044A
CN115879044A CN202211481173.0A CN202211481173A CN115879044A CN 115879044 A CN115879044 A CN 115879044A CN 202211481173 A CN202211481173 A CN 202211481173A CN 115879044 A CN115879044 A CN 115879044A
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胡坤
汪太平
沈庆
付青太
李奇越
李帷韬
柯艳国
李永熙
张斌
刘翔
马欢
孙伟
陈明阳
崔忠营
赵巨龙
夏友森
施雯
崔玮
房姗姗
张方伟
李延东
马慧芳
石永建
葛健
董翔宇
郭振宇
武文杰
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Super High Voltage Branch Of State Grid Anhui Electric Power Co ltd
Hefei University of Technology
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Hefei University of Technology
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Abstract

The invention discloses a GIS switching-on and switching-off state current detection method and device based on a CNN network, wherein the method comprises the following steps: collecting the opening and closing states of a disconnecting link and a grounding switch and corresponding coupling capacitance current data sets in all states of GIS equipment; preprocessing the acquired current data, and constructing a training set of the network; constructing a CNN network; optimizing the CNN network parameters by using a particle swarm optimization algorithm to obtain optimal CNN network parameters; acquiring fault current data of a disconnecting link and a grounding switch of GIS equipment in real time, preprocessing the fault current data, inputting the preprocessed data into an optimal CNN network, and outputting a GIS switching-on and switching-off state judgment result by using the optimal CNN network; the invention has the advantages that: the execution speed is fast, the real-time performance is high, and after the model is trained, the output result is more accurate, and the reliability is strong.

Description

基于CNN网络的GIS分合闸状态电流检测方法及装置GIS opening and closing state current detection method and device based on CNN network

技术领域Technical Field

本发明涉及GIS设备中刀闸分合闸状态检测领域,更具体涉及基于CNN网络的GIS分合闸状态电流检测方法及装置。The present invention relates to the field of detection of knife switch opening and closing states in GIS equipment, and more specifically to a method and device for detecting current in the opening and closing states of GIS based on a CNN network.

背景技术Background Art

气体绝缘金属封闭组合电器GIS(Gas-Insulated metal-enclosed Switchgear)是全部或部分采用气体而不采用处于大气压下的空气作为绝缘介质的金属封闭开关设备,与传统敞开式配电装置相比,GIS具有占地面积小、元件全部密封不受环境干扰、操作方便、维护工作量小设备安装方便、建设周期短等优点。Gas-Insulated Metal-enclosed Switchgear (GIS) is a metal-enclosed switchgear that uses gas in whole or in part as the insulating medium instead of air at atmospheric pressure. Compared with traditional open-type distribution devices, GIS has the advantages of small footprint, fully sealed components that are not affected by the environment, easy operation, small maintenance workload, easy equipment installation, and short construction period.

某电站500kV GIS为日本三菱公司和西安开关厂合作生产,1990年出厂,1992年投入运行;型号为500-GNS-MS50,主接线为一倍半接线,共4串12个间隔,开关、刀闸(隔离刀闸)、地刀(接地刀闸)均为气动操作机构,采用集中供气方式,额定操作气压为1.5MPa,其中刀闸33把(99相)、地刀43把(129相)。2015—2017年期间,该电站500kV GIS暴露出4起因刀闸、地刀内部机构故障导致的刀闸、地刀分合不成功的缺陷,严重影响到系统的安全稳定运行。为避免设备事故发生,需要对刀闸、地刀分合情况进行研究。The 500kV GIS of a power station was jointly produced by Mitsubishi Corporation of Japan and Xi'an Switch Factory. It was manufactured in 1990 and put into operation in 1992. The model is 500-GNS-MS50, the main wiring is one and a half times wiring, a total of 4 series and 12 intervals, the switch, knife switch (isolation knife switch), and earth knife (grounding knife switch) are all pneumatic operating mechanisms, using centralized air supply, the rated operating air pressure is 1.5MPa, including 33 knife switches (99 phases) and 43 earth knives (129 phases). During the period from 2015 to 2017, the 500kV GIS of the power station exposed 4 defects of knife switches and earth knives that failed to open and close due to internal mechanism failures, which seriously affected the safe and stable operation of the system. In order to avoid equipment accidents, it is necessary to study the opening and closing of knife switches and earth knives.

中国专利公开号CN113484741A公开了一种GIS隔离开关工作状态监测装置及方法,利用开口式电流互感器获得GIS隔离开关操作机构驱动电机动作过程随时间变化的电流值,根据操作机构驱动电机动作过程随时间变化的电流值进而间接判断隔离开关隔离刀的动作状态;利用角位移传感器获得GIS隔离开关操作机构驱动电机随时间变化的转动位移值,判断GIS隔离开关刀闸的位置状态;累计GIS隔离开关分合闸动作次数,预测GIS隔离开关的机械寿命,有效提高了隔离开关工作状态监测的准确度。但是该专利申请依赖操作机构驱动电机动作过程中的电流值以及传感器数据进行刀闸动作以及位置判断,实时性不高,当前获得的刀闸动作和位置实际上可能是历史时刻的电流以及传感器数据推算得出的刀闸历史动作和位置,导致实际判断结果并不精准,可靠性不高。Chinese patent publication number CN113484741A discloses a GIS disconnector working state monitoring device and method, which uses an open-type current transformer to obtain the current value of the GIS disconnector operating mechanism driving motor that changes with time during the operation process, and indirectly judges the operation state of the disconnector according to the current value of the operating mechanism driving motor that changes with time during the operation process; uses an angular displacement sensor to obtain the rotation displacement value of the GIS disconnector operating mechanism driving motor that changes with time, and judges the position state of the GIS disconnector knife switch; accumulates the number of GIS disconnector opening and closing operations, predicts the mechanical life of the GIS disconnector, and effectively improves the accuracy of disconnector working state monitoring. However, this patent application relies on the current value and sensor data during the operation of the operating mechanism driving motor to judge the knife switch action and position, which is not real-time. The current knife switch action and position may actually be the historical action and position of the knife switch calculated by the current and sensor data at the historical moment, resulting in the actual judgment result being inaccurate and unreliable.

发明内容Summary of the invention

本发明所要解决的技术问题在于现有技术GIS隔离开关工作状态判断方法实时性不高,判断结果不够精准,可靠性不高的问题。The technical problem to be solved by the present invention is that the existing method for judging the working state of a GIS disconnector is not real-time, the judgment result is not accurate enough, and the reliability is not high.

本发明通过以下技术手段实现解决上述技术问题的:基于CNN网络的GIS分合闸状态电流检测方法,所述方法包括:The present invention solves the above technical problems by the following technical means: a GIS opening and closing state current detection method based on a CNN network, the method comprising:

步骤一:采集GIS设备各个状态下的刀闸和地刀的开合状态以及对应的耦合电容电流数据集;Step 1: Collect the opening and closing status of the switch and ground switch in various states of the GIS equipment and the corresponding coupling capacitor current data set;

步骤二:对采集的电流数据预处理,构建网络的训练集;Step 2: Preprocess the collected current data and construct a network training set;

步骤三:构建CNN网络,其输入为训练集,输出为刀闸和地刀的开合状态;Step 3: Construct a CNN network, whose input is the training set and output is the opening and closing status of the knife switch and the ground knife;

步骤四:使用粒子群优化算法优化CNN网络参数得到最优CNN网络参数;Step 4: Use particle swarm optimization algorithm to optimize CNN network parameters to obtain the optimal CNN network parameters;

步骤五:根据最优CNN网络参数对CNN网络进行设置得到最优的CNN网络,实时采集GIS设备的刀闸和地刀故障电流数据并进行预处理以后输入到最优的CNN网络中,利用最优的CNN网络输出GIS分合闸状态判断结果。Step 5: Set the CNN network according to the optimal CNN network parameters to obtain the optimal CNN network. Collect the fault current data of the knife switch and ground switch of the GIS equipment in real time, pre-process them and input them into the optimal CNN network. Use the optimal CNN network to output the GIS opening and closing status judgment results.

有益效果:本发明通过构建CNN网络并利用粒子群优化算法优化CNN网络参数得到最优CNN网络参数,从而获得最优的CNN网络,最终利用最优的CNN网络对实时采集的刀闸和地刀故障电流数据进行判断,输出GIS分合闸状态,相比现有技术传感器测量的方式,采用训练好的神经网络进行结果判定,执行速度快,实时性高,且经过训练以后,输出结果较为精准,可靠性强。Beneficial effect: The present invention obtains the optimal CNN network parameters by constructing a CNN network and optimizing the CNN network parameters using a particle swarm optimization algorithm, thereby obtaining the optimal CNN network. Finally, the optimal CNN network is used to judge the real-time collected knife switch and ground switch fault current data, and output the GIS opening and closing status. Compared with the existing sensor measurement method, the trained neural network is used for result judgment, which has fast execution speed and high real-time performance. After training, the output results are more accurate and reliable.

进一步地,所述步骤一包括:Furthermore, the step 1 comprises:

GIS设备处于热备状态时,每组刀闸、地刀开合情况为刀闸合闸、地刀分闸,记录地刀分合状态YH={y1 H,y2 H…yk H…yK H},同时采集电流数据集IH={I1 H,I2 H…Ik H…IK H},其中

Figure BDA0003961656260000031
表示热备状态下第k个地刀电流;When the GIS equipment is in hot standby state, the opening and closing status of each group of knife switches and earth switches is knife switch closed and earth switch opened. The earth switch opening and closing status Y H = {y 1 H ,y 2 H …y k H …y K H } is recorded, and the current data set I H = {I 1 H ,I 2 H …I k H …I K H } is collected at the same time.
Figure BDA0003961656260000031
Indicates the kth ground switch current in hot standby state;

GIS设备处于冷备用状态时,每组刀闸、地刀开合情况为刀闸分闸、地刀分闸,记录地刀和刀闸分合状态YC={y1 C,y2 C…yk C…yK C,y1 C',y2 C'…ym C'…yM C'},同时采集地刀和刀闸电流数据集IC={I1 C,I2 C…Ik C…IK C,I1 C',I2 C'…Im C'…IM C'},其中

Figure BDA0003961656260000032
表示冷备用状态下第k个地刀电流,
Figure BDA0003961656260000033
表示冷备用状态下第m个刀闸电流;When the GIS equipment is in cold standby state, the opening and closing status of each group of knife switches and earth switches is knife switch open and earth switch open. The opening and closing status of earth switches and knife switches Y C = {y 1 C ,y 2 C …y k C …y K C ,y 1 C' ,y 2 C' …y m C' …y M C' } is recorded. At the same time, the current data set of earth switches and knife switches I C = {I 1 C ,I 2 C …I k C …I K C ,I 1 C' ,I 2 C' …I m C' …I M C' } is collected, where
Figure BDA0003961656260000032
Indicates the kth ground switch current in cold standby state,
Figure BDA0003961656260000033
Indicates the current of the mth switch in the cold standby state;

GIS设备处于检修状态时,每组刀闸、地刀开合情况为刀闸分闸、地刀合闸,记录刀闸分合状态,YR={y1 R,y2 R…ym R…yM R},同时采集刀闸电流数据集IR={I1 R,I2 R…Im R…IM R},其中

Figure BDA0003961656260000034
表示检修状态下第m个边界刀闸电流。When the GIS equipment is under maintenance, the opening and closing status of each group of switch and earth switch is switch open and earth switch closed. The switch opening and closing status is recorded, Y R = {y 1 R ,y 2 R …y m R …y M R }, and the switch current data set IR = {I 1 R ,I 2 R …I m R …I M R } is collected at the same time, where
Figure BDA0003961656260000034
Indicates the current of the mth boundary switch in the maintenance state.

进一步地,所述步骤二包括:Furthermore, the step 2 comprises:

S21、采集刀闸和地刀故障电流数据,对故障电流信号作小波变换,从而获取小波系数Wi(a,b)和待选频率finsS21, collecting the fault current data of the switch and the ground switch, performing wavelet transform on the fault current signal, thereby obtaining the wavelet coefficients Wi (a, b) and the selected frequency fins ;

S22、通过公式

Figure BDA0003961656260000041
得到零矩阵,其中,设(Δa)k=ak-ak-1,Δf=fk-fk-1,ak为第k个瞬时分量的尺度因子,fk是第k个瞬时分量的中心频率,取k∈[0,na],fs为信号采样频率;由S21中的fins,根据式fins=2kΔf·fs/na计算得到k值,其中
Figure BDA0003961656260000042
S22, through the formula
Figure BDA0003961656260000041
The zero matrix is obtained, where (Δa) k = ak - ak-1 , Δf = f k - f k-1 , ak is the scale factor of the kth instantaneous component, f k is the center frequency of the kth instantaneous component, k∈[0, na ], f s is the signal sampling frequency; from fins in S21, the k value is calculated according to the formula fins = 2 kΔf ·f s / na , where
Figure BDA0003961656260000042

判断k∈[0,na]是否满足,若满足则有Determine whether k∈[0, n a ] satisfies. If so, then

Figure BDA0003961656260000043
Figure BDA0003961656260000043

重复上述步骤预设次数,将信号变得纤细从而清楚地呈现在时频图上,Repeat the above steps for a preset number of times to make the signal thinner and clearly present it on the time-frequency diagram.

经过式

Figure BDA0003961656260000044
重建信号及其各个分量,其中
Figure BDA0003961656260000045
Re为取实部。Passing
Figure BDA0003961656260000044
Reconstruct the signal and its individual components, where
Figure BDA0003961656260000045
R e is the real part.

更进一步地,所述S21包括:Furthermore, the S21 includes:

选择一个小波母函数ψ(t),使它的傅里叶变换Ψ(ω)满足如下小波函数的可容许性条件Select a wavelet mother function ψ(t) so that its Fourier transform Ψ(ω) satisfies the following admissibility condition of the wavelet function:

Figure BDA0003961656260000046
Figure BDA0003961656260000046

选择伸缩因子a,平移因子b,将小波母函数ψ(t)进行伸缩和平移操作,可得小波基函数:Select the scaling factor a and the translation factor b, scale and translate the wavelet mother function ψ(t), and you can get the wavelet basis function:

Figure BDA0003961656260000047
Figure BDA0003961656260000047

按下式对电流信号进行小波变换,得到小波系数Wi(a,b)Perform wavelet transform on the current signal according to the following formula to obtain the wavelet coefficients Wi (a, b):

Figure BDA0003961656260000048
Figure BDA0003961656260000048

其中ψ*(t)是ψ(t)的复共轭。where ψ * (t) is the complex conjugate of ψ(t).

进一步地,所述CNN网络包括顺序连接的输入层、卷积层、池化层、全连接层和输出层,所述卷积层为3层,卷积核提取电流时频谱图的特征,所述池化层也有3个,分别将3个卷积层输出数据进行降维;输出层由Softmax模块和分类模块构成。Furthermore, the CNN network includes a sequentially connected input layer, a convolution layer, a pooling layer, a fully connected layer and an output layer. The convolution layer has three layers, and the convolution kernel extracts the characteristics of the current spectrum. The pooling layer also has three layers, and the output data of the three convolution layers are respectively reduced in dimension; the output layer is composed of a Softmax module and a classification module.

更进一步地,所述卷积层通过公式

Figure BDA0003961656260000051
得到当前神经元
Figure BDA0003961656260000052
式中,Mj为输入到神经元j的向量总数,
Figure BDA0003961656260000053
为前一层输入神经元的特征图;kij l为卷积核的权重;bj为第j种特征图的偏置;σ为ReLU激活函数;Furthermore, the convolutional layer is constructed by the formula
Figure BDA0003961656260000051
Get the current neuron
Figure BDA0003961656260000052
Where Mj is the total number of vectors input to neuron j,
Figure BDA0003961656260000053
is the feature map of the input neuron in the previous layer; ki j l is the weight of the convolution kernel; b j is the bias of the jth feature map; σ is the ReLU activation function;

Softmax模块输出Softmax module output

Figure BDA0003961656260000054
Figure BDA0003961656260000054

式中,xj为全连接层的第j个输出,k为Softmax模块输入个数,k=2,则P1、P2为Where xj is the jth output of the fully connected layer, k is the number of inputs to the Softmax module, k = 2, then P1 and P2 are

Figure BDA0003961656260000055
Figure BDA0003961656260000055

P1、P2分别表示输出为y=1和y=0的概率;将概率值P1、P2输入分类模块,在分类模块中计算交叉损失熵函数值L,其中

Figure BDA0003961656260000056
yi为事件标签值,y1=1,y2=0。P1 and P2 represent the probabilities of outputting y=1 and y=0 respectively; the probability values P1 and P2 are input into the classification module, and the cross loss entropy function value L is calculated in the classification module, where
Figure BDA0003961656260000056
yi is the event label value, y1 = 1, y2 = 0.

更进一步地,所述CNN网络还包括Inception-v3结构,该结构使用大小为1×n和n×1的滤波器来代替CNN网络中n×n的卷积。Furthermore, the CNN network also includes an Inception-v3 structure, which uses filters of size 1×n and n×1 to replace the n×n convolution in the CNN network.

更进一步地,所述步骤四包括:设置损失函数Lloss,当CNN网络的损失值L<Lloss,网络训练可靠,将P1、P2中数值较大的标签值作为网络输出;否则表示网络权重分配不当,利用采用粒子群优化算法重新分配权值重复上述过程直至满足网络输出条件得到最优CNN网络参数。Furthermore, the step four includes: setting the loss function L loss , when the loss value L of the CNN network is less than L loss , the network training is reliable, and the label value with a larger value in P1 and P2 is used as the network output; otherwise, it indicates that the network weight distribution is improper, and the particle swarm optimization algorithm is used to reallocate the weights and repeat the above process until the network output conditions are met to obtain the optimal CNN network parameters.

更进一步地,所述粒子群优化算法重新分配权值,包括:Furthermore, the particle swarm optimization algorithm reallocates weights, including:

S41、在CNN网络计算出期望值与实际值之间的误差后,每个粒子都将CNN网络的批处理的样本数量batchsize、训练数据丢弃率dropout、卷积核数量Nc、卷积核大小Mc和网络初始偏置bj作为待优化超参数,待优化超参数作为粒子维度;S41. After the CNN network calculates the error between the expected value and the actual value, each particle takes the batch size of samples in the CNN network, the training data discard rate, the number of convolution kernels N c , the convolution kernel size Mc and the network initial bias b j as the hyperparameters to be optimized, and the hyperparameters to be optimized are used as the particle dimensions;

S42、以CNN网络的期望值与实际值之间的误差作为适应度函数,计算每个粒子的适应度值,将n次迭代更新中每个粒子出现过的最优点作为个体最优解Pbest保存,再与整体种群粒子比较,选取全局最优值Gbest保存;S42, using the error between the expected value and the actual value of the CNN network as the fitness function, calculating the fitness value of each particle, saving the optimal point of each particle in n iterative updates as the individual optimal solution P best , and then comparing it with the particles of the entire population, selecting the global optimal value G best and saving it;

S43、比较粒子的适应度值与个体的最优适应度值,若粒子的适应度值较大,将其替换为个体最优适应度值;S43, comparing the fitness value of the particle with the optimal fitness value of the individual, if the fitness value of the particle is larger, replacing it with the optimal fitness value of the individual;

S44、比较所有粒子的个体最优适应度值与群体全局最优适应度值,若个体最优适应度值较大,则将其替换为全局最优适应度值;S44, comparing the individual optimal fitness values of all particles with the global optimal fitness value of the group, if the individual optimal fitness value is larger, it is replaced by the global optimal fitness value;

S45、更新粒子的速度与位置,返回执行步骤S42;S45, update the speed and position of the particle, and return to execute step S42;

S46、比较当前迭代次数和最大迭代次数的大小,当n<N时,迭代继续;当n>N时,迭代结束,或者达到最小误差时迭代结束,若两个迭代结束条件均不满足则返回步骤S42,否则退出循环得到全局最优适应度值,全局最优适应度值对应的粒子的各参数即为粒子群寻优得到的最优CNN网络参数。S46. Compare the current number of iterations with the maximum number of iterations. When n<N, the iteration continues; when n>N, the iteration ends, or the iteration ends when the minimum error is reached. If both iteration end conditions are not met, return to step S42, otherwise exit the loop to obtain the global optimal fitness value. The parameters of the particles corresponding to the global optimal fitness value are the optimal CNN network parameters obtained by the particle swarm optimization.

本发明还提供基于CNN网络的GIS分合闸状态电流检测装置,所述装置包括:The present invention also provides a GIS opening and closing state current detection device based on a CNN network, the device comprising:

数据采集模块,用于采集GIS设备各个状态下的刀闸和地刀的开合状态以及对应的耦合电容电流数据集;The data acquisition module is used to collect the opening and closing status of the knife switch and the ground knife in various states of the GIS equipment and the corresponding coupling capacitor current data set;

训练集构建模块,用于对采集的电流数据预处理,构建网络的训练集;A training set construction module is used to pre-process the collected current data and construct a training set for the network;

网络构建模块,用于构建CNN网络,其输入为训练集,输出为刀闸和地刀的开合状态;The network construction module is used to construct a CNN network, whose input is the training set and output is the opening and closing status of the knife switch and the ground knife;

参数优化模块,用于使用粒子群优化算法优化CNN网络参数得到最优CNN网络参数;Parameter optimization module, used to optimize CNN network parameters using particle swarm optimization algorithm to obtain the optimal CNN network parameters;

结果输出模块,用于根据最优CNN网络参数对CNN网络进行设置得到最优的CNN网络,实时采集GIS设备的刀闸和地刀故障电流数据并进行预处理以后输入到最优的CNN网络中,利用最优的CNN网络输出GIS分合闸状态判断结果。The result output module is used to set the CNN network according to the optimal CNN network parameters to obtain the optimal CNN network, collect the switch and ground switch fault current data of the GIS equipment in real time, and input them into the optimal CNN network after preprocessing, and use the optimal CNN network to output the GIS opening and closing status judgment result.

进一步地,所述数据采集模块还用于:Furthermore, the data acquisition module is also used for:

GIS设备处于热备状态时,每组刀闸、地刀开合情况为刀闸合闸、地刀分闸,记录地刀分合状态YH={y1 H,y2 H…yk H…yK H},同时采集电流数据集IH={I1 H,I2 H…Ik H…IK H},其中

Figure BDA0003961656260000071
表示热备状态下第k个地刀电流;When the GIS equipment is in hot standby state, the opening and closing status of each group of knife switches and earth switches is knife switch closed and earth switch opened. The earth switch opening and closing status Y H = {y 1 H ,y 2 H …y k H …y K H } is recorded, and the current data set I H = {I 1 H ,I 2 H …I k H …I K H } is collected at the same time.
Figure BDA0003961656260000071
Indicates the kth ground switch current in hot standby state;

GIS设备处于冷备用状态时,每组刀闸、地刀开合情况为刀闸分闸、地刀分闸,记录地刀和刀闸分合状态YC={y1 C,y2 C…yk C…yK C,y1 C',y2 C'…ym C'…yM C'},同时采集地刀和刀闸电流数据集IC={I1 C,I2 C…Ik C…IK C,I1 C',I2 C'…Im C'…IM C'},其中

Figure BDA0003961656260000072
表示冷备用状态下第k个地刀电流,
Figure BDA0003961656260000073
表示冷备用状态下第m个刀闸电流;When the GIS equipment is in cold standby state, the opening and closing status of each group of knife switches and earth switches is knife switch open and earth switch open. The opening and closing status of earth switches and knife switches Y C = {y 1 C ,y 2 C …y k C …y K C ,y 1 C' ,y 2 C' …y m C' …y M C' } is recorded. At the same time, the current data set of earth switches and knife switches I C = {I 1 C ,I 2 C …I k C …I K C ,I 1 C' ,I 2 C' …I m C' …I M C' } is collected, where
Figure BDA0003961656260000072
Indicates the kth ground switch current in cold standby state,
Figure BDA0003961656260000073
Indicates the current of the mth switch in the cold standby state;

GIS设备处于检修状态时,每组刀闸、地刀开合情况为刀闸分闸、地刀合闸,记录刀闸分合状态,YR={y1 R,y2 R…ym R…yM R},同时采集刀闸电流数据集IR={I1 R,I2 R…Im R…IM R},其中

Figure BDA0003961656260000081
表示检修状态下第m个边界刀闸电流。When the GIS equipment is under maintenance, the opening and closing status of each group of knife switches and earth switches is knife switch open and earth switch closed. The knife switch opening and closing status is recorded, Y R = {y 1 R ,y 2 R …y m R …y M R }, and the knife switch current data set IR = {I 1 R ,I 2 R …I m R …I M R } is collected at the same time, where
Figure BDA0003961656260000081
Indicates the current of the mth boundary switch in the maintenance state.

进一步地,所述训练集构建模块还用于:Furthermore, the training set construction module is also used for:

S21、采集刀闸和地刀故障电流数据,对故障电流信号作小波变换,从而获取小波系数Wi(a,b)和待选频率finsS21, collecting the fault current data of the switch and the ground switch, performing wavelet transform on the fault current signal, thereby obtaining the wavelet coefficients Wi (a, b) and the selected frequency fins ;

S22、通过公式

Figure BDA0003961656260000082
得到零矩阵,其中,(Δa)k=ak-ak-1,Δf=fk-fk-1,ak为第k个瞬时分量的尺度因子,fk是第k个瞬时分量的中心频率,取k∈[0,na],fs为信号采样频率;由S21中的fins,根据式fins=2kΔf·fs/na计算得到k值,其中
Figure BDA0003961656260000083
S22, through the formula
Figure BDA0003961656260000082
The zero matrix is obtained, where (Δa) k = ak - ak-1 , Δf = f k - f k-1 , ak is the scale factor of the kth instantaneous component, f k is the center frequency of the kth instantaneous component, k∈[0, na ], and f s is the signal sampling frequency; the k value is calculated from fins in S21 according to the formula fins = 2 kΔf ·f s / na , where
Figure BDA0003961656260000083

判断k∈[0,na]是否满足,若满足则有Determine whether k∈[0, n a ] satisfies. If so, then

Figure BDA0003961656260000084
Figure BDA0003961656260000084

重复上述步骤预设次数,将信号变得纤细从而清楚地呈现在时频图上,Repeat the above steps for a preset number of times to make the signal thinner and clearly present it on the time-frequency diagram.

经过式

Figure BDA0003961656260000085
重建信号及其各个分量,其中
Figure BDA0003961656260000086
Re为取实部。Passing
Figure BDA0003961656260000085
Reconstruct the signal and its individual components, where
Figure BDA0003961656260000086
R e is the real part.

更进一步地,所述S21包括:Furthermore, the S21 includes:

选择一个小波母函数ψ(t),使它的傅里叶变换Ψ(w)满足如下小波函数的可容许性条件Select a wavelet mother function ψ(t) so that its Fourier transform Ψ(w) satisfies the following admissibility condition of the wavelet function:

Figure BDA0003961656260000087
Figure BDA0003961656260000087

选择伸缩因子a,平移因子b,将小波母函数ψ(t)进行伸缩和平移操作,可得小波基函数:Select the scaling factor a and the translation factor b, scale and translate the wavelet mother function ψ(t), and you can get the wavelet basis function:

Figure BDA0003961656260000091
Figure BDA0003961656260000091

按下式对电流信号进行小波变换,得到小波系数Wi(a,b)Perform wavelet transform on the current signal according to the following formula to obtain the wavelet coefficients Wi (a, b):

Figure BDA0003961656260000092
Figure BDA0003961656260000092

其中ψ*(t)是ψ(t)的复共轭。where ψ * (t) is the complex conjugate of ψ(t).

进一步地,所述CNN网络包括顺序连接的输入层、卷积层、池化层、全连接层和输出层,所述卷积层为3层,卷积核提取电流时频谱图的特征,所述池化层也有3个,分别将3个卷积层输出数据进行降维;输出层由Softmax模块和分类模块构成。Furthermore, the CNN network includes a sequentially connected input layer, a convolution layer, a pooling layer, a fully connected layer and an output layer. The convolution layer has three layers, and the convolution kernel extracts the characteristics of the current spectrum. The pooling layer also has three layers, and the output data of the three convolution layers are respectively reduced in dimension; the output layer is composed of a Softmax module and a classification module.

更进一步地,所述卷积层通过公式

Figure BDA0003961656260000093
得到当前神经元
Figure BDA0003961656260000094
式中,Mj为输入到神经元j的向量总数,
Figure BDA0003961656260000095
为前一层输入神经元的特征图;kij l为卷积核的权重;bj为第j种特征图的偏置;σ为ReLU激活函数;Furthermore, the convolutional layer is constructed by the formula
Figure BDA0003961656260000093
Get the current neuron
Figure BDA0003961656260000094
Where Mj is the total number of vectors input to neuron j,
Figure BDA0003961656260000095
is the feature map of the input neuron in the previous layer; k ij l is the weight of the convolution kernel; b j is the bias of the jth feature map; σ is the ReLU activation function;

Softmax模块输出Softmax module output

Figure BDA0003961656260000096
Figure BDA0003961656260000096

式中,xj为全连接层的第j个输出,k为Softmax模块输入个数,k=2,则P1、P2为Where xj is the jth output of the fully connected layer, k is the number of inputs to the Softmax module, k = 2, then P1 and P2 are

Figure BDA0003961656260000097
Figure BDA0003961656260000097

P1、P2分别表示输出为y=1和y=0的概率;将概率值P1、P2输入分类模块,在分类模块中计算交叉损失熵函数值L,其中

Figure BDA0003961656260000101
yi为事件标签值,y1=1,y2=0。P1 and P2 represent the probabilities of outputting y=1 and y=0 respectively; the probability values P1 and P2 are input into the classification module, and the cross loss entropy function value L is calculated in the classification module, where
Figure BDA0003961656260000101
yi is the event label value, y1 = 1, y2 = 0.

更进一步地,所述CNN网络还包括Inception-v3结构,该结构使用大小为1×n和n×1的滤波器来代替CNN网络中n×n的卷积。Furthermore, the CNN network also includes an Inception-v3 structure, which uses filters of size 1×n and n×1 to replace the n×n convolution in the CNN network.

更进一步地,所述参数优化模块还用于:设置损失函数Lloss,当CNN网络的损失值L<Lloss,网络训练可靠,将P1、P2中数值较大的标签值作为网络输出;否则表示网络权重分配不当,利用采用粒子群优化算法重新分配权值重复上述过程直至满足网络输出条件得到最优CNN网络参数。Furthermore, the parameter optimization module is also used to: set the loss function L loss , when the loss value L of the CNN network < L loss , the network training is reliable, and the label value with a larger value in P1 and P2 is used as the network output; otherwise, it means that the network weight distribution is improper, and the particle swarm optimization algorithm is used to reallocate the weights and repeat the above process until the network output conditions are met to obtain the optimal CNN network parameters.

更进一步地,所述粒子群优化算法重新分配权值,包括:Furthermore, the particle swarm optimization algorithm reallocates weights, including:

S41、在CNN网络计算出期望值与实际值之间的误差后,每个粒子都将CNN网络的批处理的样本数量batchsize、训练数据丢弃率dropout、卷积核数量Nc、卷积核大小Mc和网络初始偏置bj作为待优化超参数,待优化超参数作为粒子维度;S41. After the CNN network calculates the error between the expected value and the actual value, each particle takes the batch size of samples in the CNN network, the training data discard rate, the number of convolution kernels N c , the convolution kernel size Mc and the network initial bias b j as the hyperparameters to be optimized, and the hyperparameters to be optimized are used as the particle dimensions;

S42、以CNN网络的期望值与实际值之间的误差作为适应度函数,计算每个粒子的适应度值,将n次迭代更新中每个粒子出现过的最优点作为个体最优解Pbest保存,再与整体种群粒子比较,选取全局最优值Gbest保存;S42, using the error between the expected value and the actual value of the CNN network as the fitness function, calculating the fitness value of each particle, saving the optimal point of each particle in n iterative updates as the individual optimal solution P best , and then comparing it with the particles of the entire population, selecting the global optimal value G best and saving it;

S43、比较粒子的适应度值与个体的最优适应度值,若粒子的适应度值较大,将其替换为个体最优适应度值;S43, comparing the fitness value of the particle with the optimal fitness value of the individual, if the fitness value of the particle is larger, replacing it with the optimal fitness value of the individual;

S44、比较所有粒子的个体最优适应度值与群体全局最优适应度值,若个体最优适应度值较大,则将其替换为全局最优适应度值;S44, comparing the individual optimal fitness values of all particles with the global optimal fitness value of the group, if the individual optimal fitness value is larger, it is replaced by the global optimal fitness value;

S45、更新粒子的速度与位置,返回执行步骤S42;S45, update the speed and position of the particle, and return to execute step S42;

S46、比较当前迭代次数和最大迭代次数的大小,当n<N时,迭代继续;当n>N时,迭代结束,或者达到最小误差时迭代结束,若两个迭代结束条件均不满足则返回步骤S42,否则退出循环得到全局最优适应度值,全局最优适应度值对应的粒子的各参数即为粒子群寻优得到的最优CNN网络参数。S46. Compare the current number of iterations with the maximum number of iterations. When n<N, the iteration continues; when n>N, the iteration ends, or the iteration ends when the minimum error is reached. If both iteration end conditions are not met, return to step S42, otherwise exit the loop to obtain the global optimal fitness value. The parameters of the particles corresponding to the global optimal fitness value are the optimal CNN network parameters obtained by the particle swarm optimization.

本发明的优点在于:本发明通过构建CNN网络并利用粒子群优化算法优化CNN网络参数得到最优CNN网络参数,从而获得最优的CNN网络,最终利用最优的CNN网络对实时采集的刀闸和地刀故障电流数据进行判断,输出GIS分合闸状态,相比现有技术传感器测量的方式,采用训练好的神经网络进行结果判定,执行速度快,实时性高,且经过训练以后,输出结果较为精准,可靠性强。The advantages of the present invention are as follows: the present invention obtains the optimal CNN network parameters by constructing a CNN network and optimizing the CNN network parameters using a particle swarm optimization algorithm, thereby obtaining the optimal CNN network, and finally using the optimal CNN network to judge the real-time collected knife switch and ground switch fault current data, and output the GIS opening and closing status. Compared with the sensor measurement method in the prior art, the present invention uses a trained neural network to judge the results, with fast execution speed and high real-time performance, and after training, the output results are more accurate and reliable.

附图说明BRIEF DESCRIPTION OF THE DRAWINGS

图1为现有技术刀闸与地刀三种情况原理图;FIG1 is a schematic diagram of three situations of knife switches and ground switches in the prior art;

图2为本发明实施例1所公开的基于CNN网络的GIS分合闸状态电流检测方法中CNN网络架构图;FIG2 is a diagram of the CNN network architecture in the GIS opening and closing state current detection method based on the CNN network disclosed in Example 1 of the present invention;

图3为本发明实施例1所公开的基于CNN网络的GIS分合闸状态电流检测方法中inception模块结构示意图;FIG3 is a schematic diagram of the structure of the inception module in the GIS opening and closing state current detection method based on the CNN network disclosed in Example 1 of the present invention;

图4为本发明实施例1所公开的基于CNN网络的GIS分合闸状态电流检测方法中粒子群优化算法流程图。FIG4 is a flow chart of a particle swarm optimization algorithm in a GIS opening and closing state current detection method based on a CNN network disclosed in Example 1 of the present invention.

具体实施方式DETAILED DESCRIPTION

为使本发明实施例的目的、技术方案和优点更加清楚,下面将结合本发明实施例,对本发明实施例中的技术方案进行清楚、完整地描述,显然,所描述的实施例是本发明一部分实施例,而不是全部的实施例。基于本发明中的实施例,本领域普通技术人员在没有作出创造性劳动前提下所获得的所有其他实施例,都属于本发明保护的范围。In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

实施例1Example 1

发明人对刀闸、地刀分合情况进行研究,对刀闸、地刀的故障进行了统计分析,统计分析发现GIS设备的共性问题为因内部传动机构故障而使刀闸、地刀未按预定指令完成动作,不存在半分或半合状态。相邻平行线路处于强电场中,会产生感应电压,并在地刀合闸状态通过地刀接地板产生电耦合电容电流,而分闸状态接地板中无线路耦合电容电流。刀闸断口两侧均压罩可视为电容的两个极板,断口可等效为一个固定电容,断口的一端有高压、另一端接地,必然有耦合电容电流通过断口,并经地刀接地板流入地网。如图1所示,刀闸与地刀具有以下三种情况:The inventor studied the opening and closing conditions of knife switches and earth switches, and conducted a statistical analysis of the failures of knife switches and earth switches. The statistical analysis found that the common problem of GIS equipment is that the knife switches and earth switches fail to complete the action according to the predetermined instructions due to the failure of the internal transmission mechanism, and there is no half-open or half-closed state. Adjacent parallel lines are in a strong electric field, which will generate an induced voltage and generate an electric coupling capacitor current through the earth switch grounding plate when the earth switch is in the closed state, while there is no line coupling capacitor current in the grounding plate in the open state. The voltage-equalizing covers on both sides of the knife switch break can be regarded as the two plates of the capacitor, and the break can be equivalent to a fixed capacitor. There is high voltage at one end of the break and the other end is grounded. There must be a coupling capacitor current passing through the break and flowing into the ground grid through the earth switch grounding plate. As shown in Figure 1, the knife switch and the earth switch have the following three situations:

1)刀闸断口与地刀断口串联(见图1(a)),则耦合电容电流计算公式如下:1) The knife switch break is connected in series with the ground knife break (see Figure 1(a)), and the coupling capacitor current calculation formula is as follows:

Figure BDA0003961656260000121
Figure BDA0003961656260000121

式中,j是虚数单位。Where j is the imaginary unit.

2)刀闸处于断开状态、地刀处于合闸状态(见图1(b)),则耦合电容电流计算公式如下:2) When the knife switch is in the open state and the ground switch is in the closed state (see Figure 1(b)), the coupling capacitor current calculation formula is as follows:

Ic=j2πfCgUI c =j2πfC g U

3)地刀处于断开状态、刀闸处于合闸状态(见图1(c)),则耦合电容电流计算公式如下:3) When the earth switch is in the disconnected state and the knife switch is in the closed state (see Figure 1(c)), the coupling capacitor current calculation formula is as follows:

Ic=j2πfCjUI c =j2πfC j U

对于GIS刀闸、地刀的断口,因其为纯容性结构,故阻性电流为0,全泄漏电流即是耦合电容电流;因此,通过检测刀闸、地刀倒闸操作过程中耦合电容电流的特征变化,即可对刀闸、地刀分合情况作出判断。For the fracture of GIS knife switch and earth switch, since it is a purely capacitive structure, the resistive current is 0, and the total leakage current is the coupling capacitor current; therefore, by detecting the characteristic changes of the coupling capacitor current during the switching operation of the knife switch and earth switch, the opening and closing conditions of the knife switch and earth switch can be judged.

基于上述分析,本发明提供基于CNN网络的GIS分合闸状态耦合电容电流检测方法,通过采集刀闸、地刀倒闸操作过程中耦合电容电流的特征变化实现GIS分合闸的判断。以下详细介绍本发明的方法过程。Based on the above analysis, the present invention provides a GIS opening and closing state coupling capacitor current detection method based on CNN network, which realizes the judgment of GIS opening and closing by collecting the characteristic changes of coupling capacitor current during the operation of knife switch and ground knife. The method process of the present invention is described in detail below.

S1、采集GIS设备各个状态下的刀闸和地刀的开合状态以及耦合电容电流数据集;该步骤的具体过程如下:S1. Collect the opening and closing status of the knife switch and the ground knife in each state of the GIS equipment and the coupling capacitor current data set; the specific process of this step is as follows:

在GIS设备停电和复电时,采集各个设备电流状态;处于热备状态时,每组刀闸、地刀开合情况为:刀闸合闸、地刀分闸;记录地刀分合状态YH={y1 H,y2 H…yk H…yK H},同时采集电流数据集IH={I1 H,I2 H…Ik H…IK H}其中

Figure BDA0003961656260000134
表示热备状态下第k个地刀电流;处于冷备用状态时,每组刀闸、地刀开合情况为:刀闸分闸、地刀分闸;记录地刀和刀闸分合状态YC={y1 C,y2 C…yk C…yK C,y1 C',y2 C'…ym C'…yM C'},同时采集地刀和刀闸电流数据集IC={I1 C,I2 C…Ik C…IK C,I1 C',I2 C'…Im C'…IM C'},中
Figure BDA0003961656260000131
表示冷备用状态下第k个地刀电流,中
Figure BDA0003961656260000132
表示冷备用状态下第m个刀闸电流;处于检修状态时,每组刀闸、地刀开合情况为:刀闸分闸、地刀合闸;记录刀闸分合状态,YR={y1 R,y2 R…ym R…yM R},同时采集刀闸电流数据集IR={I1 R,I2 R…Im R…IM R},其中
Figure BDA0003961656260000133
表示检修状态下第m个边界刀闸电流。When the GIS equipment is powered off and restored, the current status of each device is collected; when in hot standby state, the opening and closing status of each group of knife switches and earth switches is: knife switch closed, earth switch open; record the earth switch opening and closing status Y H = {y 1 H ,y 2 H …y k H …y K H }, and collect the current data set I H = {I 1 H ,I 2 H …I k H …I K H } at the same time
Figure BDA0003961656260000134
Indicates the kth earth switch current in the hot standby state; in the cold standby state, the opening and closing conditions of each group of switch and earth switch are: switch open, earth switch open; record the opening and closing status of earth switch and switch Y C = {y 1 C ,y 2 C …y k C …y K C ,y 1 C' ,y 2 C' …y m C' …y M C' }, and collect the earth switch and switch current data set I C = {I 1 C ,I 2 C …I k C …I K C ,I 1 C' ,I 2 C' …I m C' …I M C' } at the same time,
Figure BDA0003961656260000131
Indicates the kth ground switch current in cold standby state,
Figure BDA0003961656260000132
Indicates the current of the mth knife switch in the cold standby state; when in the maintenance state, the opening and closing status of each set of knife switches and earth switches is: knife switch open, earth switch closed; record the knife switch opening and closing status, Y R = {y 1 R ,y 2 R ...y m R ...y M R }, and collect the knife switch current data set IR = {I 1 R ,I 2 R ...I m R ...I M R }, where
Figure BDA0003961656260000133
Indicates the current of the mth boundary switch in the maintenance state.

S2、对采集的电流信号预处理,采用小波分解算法,获知信号的频带信息,去除一些杂波信号,完成对信号的降噪处理,构建网络的训练集;具体过程如下:S2. Preprocess the collected current signal, use the wavelet decomposition algorithm to obtain the frequency band information of the signal, remove some clutter signals, complete the noise reduction processing of the signal, and construct the network training set; the specific process is as follows:

S21、采集刀闸和地刀故障电流数据I(t),对故障电流信号作小波变换,从而获取小波系数Wi(a,b)和待选频率fins,选择一个小波母函数ψ(t),使它的傅里叶变换Ψ(ω)满足小波函数的可容许性条件如下S21, collect the fault current data I(t) of the switch and the ground switch, perform wavelet transform on the fault current signal, thereby obtaining the wavelet coefficients Wi (a, b) and the selected frequency fins , and select a wavelet mother function ψ(t) so that its Fourier transform Ψ(ω) satisfies the admissibility condition of the wavelet function as follows:

Figure BDA0003961656260000141
Figure BDA0003961656260000141

选择伸缩因子(尺度因子)a,平移因子b,将小波母函数ψ(t)进行伸缩和平移操作,可得小波基函数:Select the scaling factor a and the translation factor b, and perform scaling and translation operations on the wavelet mother function ψ(t) to obtain the wavelet basis function:

Figure BDA0003961656260000142
Figure BDA0003961656260000142

按下式对电流信号I(t)进行小波变换,得到Wi(a,b)Perform wavelet transform on the current signal I(t) as follows to obtain Wi (a, b):

Figure BDA0003961656260000143
Figure BDA0003961656260000143

其中ψ*(t)是ψ(t)的复共轭。where ψ * (t) is the complex conjugate of ψ(t).

S22、通过同步压缩小波变换SWT逆变换重建多组分信号的各个分量,将时间-尺度平面(a,b)转换到时频面(fins,b)上面来,通过下式得到Si(fk,b);S22, reconstruct the components of the multi-component signal by inverse transformation of synchronous compressed wavelet transform SWT, convert the time-scale plane (a, b) to the time-frequency plane (f ins , b), and obtain S i (f k , b) by the following formula;

Figure BDA0003961656260000144
Figure BDA0003961656260000144

其中,(Δa)k=ak-ak-1,Δf=fk-fk-1,ak为第k个瞬时分量的尺度因子,fk是第k个瞬时分量的中心频率;瞬时频率压缩在(fk-0.5(Δf)k,fk-0.5(Δf)k),锐化了时频图;取k∈[0,na],Si(fk,b)为零矩阵,信号采样频率为fs,故信号频率取值为[fs/na,fs/2];由S21中的fins,根据下式计算得到k值;Wherein, (Δa) k = ak - ak-1 , Δf = f k - f k-1 , ak is the scale factor of the kth instantaneous component, f k is the center frequency of the kth instantaneous component; the instantaneous frequency is compressed at (f k - 0.5(Δf) k , f k - 0.5(Δf) k ), which sharpens the time-frequency diagram; k∈[0, na ], S i (f k , b) is the zero matrix, the signal sampling frequency is f s , so the signal frequency is [f s / na , f s / 2]; from fins in S21, the k value is calculated according to the following formula;

fins=2kΔf·fs/na f ins = 2 kΔf ·f s /n a

其中

Figure BDA0003961656260000145
判断k∈[0,na]是否满足,若满足则有in
Figure BDA0003961656260000145
Determine whether k∈[0, n a ] satisfies. If so, then

Figure BDA0003961656260000151
Figure BDA0003961656260000151

重复上述步骤,将信号变得纤细从而清楚地呈现在时频图上,经过下式SWT反变换重建信号及其各个分量Repeat the above steps to make the signal thinner so that it can be clearly presented on the time-frequency diagram. The signal and its components are reconstructed by the following SWT inverse transform:

Figure BDA0003961656260000152
Figure BDA0003961656260000152

其中

Figure BDA0003961656260000153
Re为取实部;in
Figure BDA0003961656260000153
R e is the real part;

S3、构建CNN网络模型,网络模型主要分为输入层、CNN层、和输出层。训练集通过输入层输入模型,经过CNN层进行特征提取,生成特征向量通过输出层输出模型结果;具体过程如下:S3. Construct a CNN network model. The network model is mainly divided into input layer, CNN layer, and output layer. The training set is input into the model through the input layer, and features are extracted through the CNN layer. The feature vector is generated and the model results are output through the output layer. The specific process is as follows:

S31、构建初始CNN网络,CNN的结构包括输入层、卷积层、池化层、全连接层和输出层,其中,卷积层、池化层、全连接层组成CNN层。输入层接收小波分解处理后的电流时频谱图,以时频谱图中各个像素点作为输入。卷积层通过不同的卷积核数量和大小作用于电流时频谱图并提取其特征。为了避免出现不同的卷积核对电流时频谱图同一特征反复提取的情况,设计了3层卷积的网络结构,每个卷积层的卷积核个数分别由粒子群寻优得到的最佳网络参数,卷积核提取电流时频谱图的特征,加上偏置和激活函数便可以得到当前神经元

Figure BDA0003961656260000154
并以此组成不同的特征图,激活函数选取ReLU函数,计算公式如下:S31. Construct the initial CNN network. The structure of CNN includes input layer, convolution layer, pooling layer, fully connected layer and output layer, among which convolution layer, pooling layer and fully connected layer constitute CNN layer. The input layer receives the current time-frequency spectrum after wavelet decomposition processing, and takes each pixel in the time-frequency spectrum as input. The convolution layer acts on the current time-frequency spectrum through different numbers and sizes of convolution kernels and extracts its features. In order to avoid the situation where different convolution kernels repeatedly extract the same feature of the current time-frequency spectrum, a three-layer convolution network structure is designed. The number of convolution kernels in each convolution layer is the best network parameter obtained by particle swarm optimization. The convolution kernel extracts the features of the current time-frequency spectrum, and the current neuron can be obtained by adding bias and activation functions.
Figure BDA0003961656260000154
Different feature maps are formed in this way, and the activation function selects the ReLU function. The calculation formula is as follows:

Figure BDA0003961656260000155
Figure BDA0003961656260000155

Figure BDA0003961656260000156
Figure BDA0003961656260000156

式中,Mj为输入到神经元j的向量总数,

Figure BDA0003961656260000157
为前一层输入神经元的特征图;kij l为卷积核的权重;bj为第j种特征图的偏置;σ为ReLU激活函数;Where Mj is the total number of vectors input to neuron j,
Figure BDA0003961656260000157
is the feature map of the input neuron in the previous layer; k ij l is the weight of the convolution kernel; b j is the bias of the jth feature map; σ is the ReLU activation function;

设计了3个池化层结构,采用最大池化,目的是将卷积层输出数据进行降维,以降低数据的复杂程度。在全连接层确保其和之前的全部神经元都要有联系,负责降低池化层的矩阵数据维数,并提取特征样本,采用Softmax损失函数作为全连接层转换函数。CNN模型结构如图2所示。Three pooling layer structures are designed, and the maximum pooling is used to reduce the dimension of the convolution layer output data to reduce the complexity of the data. In the fully connected layer, it is ensured that it has connections with all previous neurons, which is responsible for reducing the dimension of the matrix data of the pooling layer and extracting feature samples. The Softmax loss function is used as the conversion function of the fully connected layer. The CNN model structure is shown in Figure 2.

S32、添加Inception模块,对于神经网络中n×n的卷积层直接替换成Inception模块,从而把粒子群寻优过程中n×n的卷积分解成1×n和n×1的滤波器,来降低CNN网络结构的复杂程度。一般在n比较大的情况下采用Inception模块替换n×n的卷积层,实际应用中,n的取值根据需要设定。CNN的网络结构是把卷积层进行堆叠,为达到更好的效果往往需要设置更多层数,使网络结构变深,添加Inception将不同的卷积层以并联的方式结合在一起,拉伸网络的宽度,降低网络结构的深度,并在同一级网络上运行多个尺寸的滤波器,降低了CNN的复杂程度。采用Inception-v3结构,该结构使用了大小为1×n和n×1的滤波器来代替n×n的卷积,它们对上一层进行了卷积和池化操作。采用此结构使得滤波器更小,降低了参数的数量,计算速度更快,提高了训练效率;inception模块结构如图3所示。S32, add Inception module, directly replace the n×n convolution layer in the neural network with Inception module, so as to decompose the n×n convolution in the particle swarm optimization process into 1×n and n×1 filters to reduce the complexity of the CNN network structure. Generally, when n is relatively large, the Inception module is used to replace the n×n convolution layer. In practical applications, the value of n is set according to needs. The network structure of CNN is to stack convolution layers. In order to achieve better results, it is often necessary to set more layers to make the network structure deeper. Adding Inception combines different convolution layers in parallel, stretches the width of the network, reduces the depth of the network structure, and runs filters of multiple sizes on the same level network, reducing the complexity of CNN. The Inception-v3 structure is used. This structure uses filters of size 1×n and n×1 to replace n×n convolution. They perform convolution and pooling operations on the previous layer. This structure makes the filter smaller, reduces the number of parameters, and increases the calculation speed, which improves the training efficiency. The structure of the Inception module is shown in Figure 3.

S33、输出层由Softmax模块和分类模块构成,x1、x2为全连接层输出,P1、P2为输出层Softmax模块输出S33, the output layer is composed of a Softmax module and a classification module, x1 and x2 are the outputs of the fully connected layer, and P1 and P2 are the outputs of the Softmax module of the output layer

Figure BDA0003961656260000161
Figure BDA0003961656260000161

式中k为Softmax模块输入个数,k=2,则P1、P2为Where k is the number of Softmax module inputs, k = 2, then P1 and P2 are

Figure BDA0003961656260000171
Figure BDA0003961656260000171

P1、P2分别表示输出为y=1和y=0的概率;将概率值P1、P2输入分类模块,在分类模块中计算交叉损失熵函数值L;P1 and P2 represent the probabilities of the output being y=1 and y=0 respectively; the probability values P1 and P2 are input into the classification module, and the cross loss entropy function value L is calculated in the classification module;

其中

Figure BDA0003961656260000172
yi为事件标签值,y1=1,y2=0;设置损失函数Lloss=1.2×10-3。当L<Lloss,网络训练可靠,将P1、P2中数值较大的标签值作为网络输出;否则表示网络权重分配不当,应重新分配权值重复上述过程直至满足。其中,如图4所示,分配权值采用粒子群优化算法,算法过程参阅以下步骤。in
Figure BDA0003961656260000172
Yi is the event label value, y1 = 1, y2 = 0; set the loss function Lloss = 1.2× 10-3 . When L< Lloss , the network training is reliable, and the label value with the larger value in P1 and P2 is used as the network output; otherwise, it means that the network weight distribution is improper, and the weight should be redistributed and the above process is repeated until it is satisfied. As shown in Figure 4, the particle swarm optimization algorithm is used to allocate weights, and the algorithm process refers to the following steps.

S4、使用粒子群优化算法来选择和优化建立的CNN网络结构和初始参数;S4, using particle swarm optimization algorithm to select and optimize the established CNN network structure and initial parameters;

S41、在CNN网络计算出期望值与实际值之间的误差后,每个粒子都将CNN网络的批处理的样本数量batchsize、训练数据丢弃率dropout、卷积核数量Nc、卷积核大小Mc和网络初始偏置bj作为待优化超参数,作为粒子维度;S41. After the CNN network calculates the error between the expected value and the actual value, each particle takes the batch size of samples in the CNN network, the training data dropout rate, the number of convolution kernels N c , the convolution kernel size Mc and the network initial bias b j as the hyperparameters to be optimized and as the particle dimensions;

S42、以CNN网络的期望值与实际值之间的误差作为适应度函数,计算每个粒子的适应度值。将n次迭代更新中每个粒子出现过的最优点作为个体最优解Pbest保存,再与整体种群粒子比较,选取全局最优值Gbest保存;S42, using the error between the expected value and the actual value of the CNN network as the fitness function, calculate the fitness value of each particle. Save the optimal point of each particle in the n-times iterative update as the individual optimal solution P best , and then compare it with the particles of the entire population, and select the global optimal value G best to save;

S43、比较粒子的适应度值与个体的最优适应度值,若粒子的适应度值较大,将其替换为个体最优适应度值;S43, comparing the fitness value of the particle with the optimal fitness value of the individual, if the fitness value of the particle is larger, replacing it with the optimal fitness value of the individual;

S44、比较所有粒子的个体最优适应度值与群体全局最优适应度值,若个体最优适应度值较大,则将其替换为全局最优适应度值。S44, comparing the individual optimal fitness values of all particles with the global optimal fitness value of the group, if the individual optimal fitness value is larger, it is replaced by the global optimal fitness value.

S45、通过下式更新粒子的速度与位置,返回执行步骤S42;S45, update the velocity and position of the particle by the following formula, and return to execute step S42;

Figure BDA0003961656260000181
Figure BDA0003961656260000181

Figure BDA0003961656260000182
Figure BDA0003961656260000182

wn为惯性权重系数,

Figure BDA0003961656260000183
表示第i个粒子在第n次迭代时的速度,
Figure BDA0003961656260000184
为全局学习因子,
Figure BDA0003961656260000185
为局部学习因子,R1和R2为(0,1)间的随机数,
Figure BDA0003961656260000186
为第n次迭代后的个体极值,
Figure BDA0003961656260000187
为第n次迭代后的群体极值,
Figure BDA0003961656260000188
为第n次迭代后的位置;w n is the inertia weight coefficient,
Figure BDA0003961656260000183
represents the velocity of the i-th particle at the n-th iteration,
Figure BDA0003961656260000184
is the global learning factor,
Figure BDA0003961656260000185
is the local learning factor, R1 and R2 are random numbers between (0, 1),
Figure BDA0003961656260000186
is the individual extreme value after the nth iteration,
Figure BDA0003961656260000187
is the population extreme value after the nth iteration,
Figure BDA0003961656260000188
is the position after the nth iteration;

同时通过下式对其中的惯性权重系数wn进行非线性递减处理,增强多目标的局部和全局搜索能力;At the same time, the inertia weight coefficient w n is processed nonlinearly through the following formula to enhance the local and global search capabilities of multiple targets;

Figure BDA0003961656260000189
Figure BDA0003961656260000189

wo初始惯性权重系数,wf为迭代结束后的惯性权重值,N为最大迭代次数;w o is the initial inertia weight coefficient, w f is the inertia weight value after the iteration ends, and N is the maximum number of iterations;

同时对学习因子

Figure BDA00039616562600001810
按下式进行更新;At the same time, the learning factor
Figure BDA00039616562600001810
Press the following formula to update;

Figure BDA00039616562600001811
Figure BDA00039616562600001811

Figure BDA00039616562600001812
Figure BDA00039616562600001812

Figure BDA00039616562600001813
为学习因子初始值。
Figure BDA00039616562600001813
is the initial value of the learning factor.

通过对学习因子

Figure BDA00039616562600001814
和惯性权重系数wn的动态调整,平衡局部和全局搜索的能力,提高粒子群算法全局搜索水平与收敛速度。Through the learning factor
Figure BDA00039616562600001814
And the dynamic adjustment of the inertia weight coefficient w n balances the local and global search capabilities and improves the global search level and convergence speed of the particle swarm algorithm.

S46、比较当前迭代次数和最大迭代次数的大小,当n<N时,迭代继续;当n>N时,迭代结束,或者达到最小误差时迭代结束,若两个迭代结束条件均不满足则返回步骤S42,否则退出循环得到全局最优适应度值,全局最优适应度值对应的粒子的各参数即为粒子群寻优得到的最优CNN网络参数。S46. Compare the current number of iterations with the maximum number of iterations. When n<N, the iteration continues; when n>N, the iteration ends, or the iteration ends when the minimum error is reached. If both iteration end conditions are not met, return to step S42, otherwise exit the loop to obtain the global optimal fitness value. The parameters of the particles corresponding to the global optimal fitness value are the optimal CNN network parameters obtained by the particle swarm optimization.

S5、根据最优CNN网络参数对CNN网络进行设置得到最优的CNN网络,实时采集GIS设备的刀闸和地刀故障电流数据并进行预处理以后输入到最优的CNN网络中,利用最优的CNN网络输出GIS分合闸状态判断结果。S5. The CNN network is set according to the optimal CNN network parameters to obtain the optimal CNN network. The fault current data of the knife switch and the ground switch of the GIS equipment are collected in real time and input into the optimal CNN network after preprocessing. The optimal CNN network is used to output the judgment result of the GIS opening and closing status.

实施例2Example 2

基于实施例1,本发明实施例2还提供基于CNN网络的GIS分合闸状态电流检测装置,所述装置包括:Based on Example 1, Example 2 of the present invention further provides a GIS opening and closing state current detection device based on a CNN network, the device comprising:

数据采集模块,用于采集GIS设备各个状态下的刀闸和地刀的开合状态以及对应的耦合电容电流数据集;The data acquisition module is used to collect the opening and closing status of the knife switch and the ground knife in various states of the GIS equipment and the corresponding coupling capacitor current data set;

训练集构建模块,用于对采集的电流数据预处理,构建网络的训练集;A training set construction module is used to pre-process the collected current data and construct a training set for the network;

网络构建模块,用于构建CNN网络,其输入为训练集,输出为刀闸和地刀的开合状态;The network construction module is used to construct a CNN network, whose input is the training set and output is the opening and closing status of the knife switch and the ground knife;

参数优化模块,用于使用粒子群优化算法优化CNN网络参数得到最优CNN网络参数;Parameter optimization module, used to optimize CNN network parameters using particle swarm optimization algorithm to obtain the optimal CNN network parameters;

结果输出模块,用于根据最优CNN网络参数对CNN网络进行设置得到最优的CNN网络,实时采集GIS设备的刀闸和地刀故障电流数据并进行预处理以后输入到最优的CNN网络中,利用最优的CNN网络输出GIS分合闸状态判断结果。The result output module is used to set the CNN network according to the optimal CNN network parameters to obtain the optimal CNN network, collect the switch and ground switch fault current data of the GIS equipment in real time, and input them into the optimal CNN network after preprocessing, and use the optimal CNN network to output the GIS opening and closing status judgment result.

具体的,所述数据采集模块还用于:Specifically, the data acquisition module is also used for:

GIS设备处于热备状态时,每组刀闸、地刀开合情况为刀闸合闸、地刀分闸,记录地刀分合状态YH={y1 H,y2 H…yk H…yK H},同时采集电流数据集IH={I1 H,I2 H…Ik H…IK H},其中

Figure BDA0003961656260000201
表示热备状态下第k个地刀电流;When the GIS equipment is in hot standby state, the opening and closing status of each group of knife switches and earth switches is knife switch closed and earth switch opened. The earth switch opening and closing status Y H = {y 1 H ,y 2 H …y k H …y K H } is recorded, and the current data set I H = {I 1 H ,I 2 H …I k H …I K H } is collected at the same time.
Figure BDA0003961656260000201
Indicates the kth ground switch current in hot standby state;

GIS设备处于冷备用状态时,每组刀闸、地刀开合情况为刀闸分闸、地刀分闸,记录地刀和刀闸分合状态YC={y1 C,y2 C…yk C…yK C,y1 C',y2 C'…ym C'…yM C'},同时采集地刀和刀闸电流数据集IC={I1 C,I2 C…Ik C…IK C,I1 C',I2 C'…Im C'…IM C'},其中

Figure BDA0003961656260000202
表示冷备用状态下第k个地刀电流,
Figure BDA0003961656260000203
表示冷备用状态下第m个刀闸电流;When the GIS equipment is in cold standby state, the opening and closing status of each group of knife switches and earth switches is knife switch open and earth switch open. The opening and closing status of earth switches and knife switches Y C = {y 1 C ,y 2 C …y k C …y K C ,y 1 C' ,y 2 C' …y m C' …y M C' } is recorded. At the same time, the current data set of earth switches and knife switches I C = {I 1 C ,I 2 C …I k C …I K C ,I 1 C' ,I 2 C' …I m C' …I M C' } is collected, where
Figure BDA0003961656260000202
Indicates the kth ground switch current in cold standby state,
Figure BDA0003961656260000203
Indicates the current of the mth switch in the cold standby state;

GIS设备处于检修状态时,每组刀闸、地刀开合情况为刀闸分闸、地刀合闸,记录刀闸分合状态,YR={y1 R,y2 R…ym R…yM R},同时采集刀闸电流数据集IR={I1 R,I2 R…Im R…IM R},其中

Figure BDA0003961656260000204
表示检修状态下第m个边界刀闸电流。When the GIS equipment is under maintenance, the opening and closing status of each group of knife switches and earth switches is knife switch open and earth switch closed. The knife switch opening and closing status is recorded, Y R = {y 1 R ,y 2 R …y m R …y M R }, and the knife switch current data set IR = {I 1 R ,I 2 R …I m R …I M R } is collected at the same time, where
Figure BDA0003961656260000204
Indicates the current of the mth boundary switch in the maintenance state.

具体的,所述训练集构建模块还用于:Specifically, the training set construction module is also used for:

S21、采集刀闸和地刀故障电流数据,对故障电流信号作小波变换,从而获取小波系数Wi(a,b)和待选频率finsS21, collecting the fault current data of the switch and the ground switch, performing wavelet transform on the fault current signal, thereby obtaining the wavelet coefficients Wi (a, b) and the selected frequency fins ;

S22、通过公式

Figure BDA0003961656260000205
得到零矩阵,其中,(Δa)k=ak-ak-1,Δf=fk-fk-1,ak为第k个瞬时分量的尺度因子,fk是第k个瞬时分量的中心频率,取k∈[0,na],fs为信号采样频率;由S21中的fins,根据式fins=2kΔf·fs/na计算得到k值,其中
Figure BDA0003961656260000206
S22, through the formula
Figure BDA0003961656260000205
The zero matrix is obtained, where (Δa) k = ak - ak-1 , Δf = f k - f k-1 , ak is the scale factor of the kth instantaneous component, f k is the center frequency of the kth instantaneous component, k∈[0, na ], and f s is the signal sampling frequency; the k value is calculated from fins in S21 according to the formula fins = 2 kΔf ·f s / na , where
Figure BDA0003961656260000206

判断k∈[0,na]是否满足,若满足则有Determine whether k∈[0, n a ] satisfies. If so, then

Figure BDA0003961656260000207
Figure BDA0003961656260000207

重复上述步骤预设次数,将信号变得纤细从而清楚地呈现在时频图上,Repeat the above steps for a preset number of times to make the signal thinner and clearly present it on the time-frequency diagram.

经过式

Figure BDA0003961656260000208
重建信号及其各个分量,其中
Figure BDA0003961656260000211
Re为取实部。Passing
Figure BDA0003961656260000208
Reconstruct the signal and its individual components, where
Figure BDA0003961656260000211
R e is the real part.

更具体的,所述S21包括:More specifically, the S21 includes:

选择一个小波母函数ψ(t),使它的傅里叶变换Ψ(ω)满足如下小波函数的可容许性条件Select a wavelet mother function ψ(t) so that its Fourier transform Ψ(ω) satisfies the following admissibility condition of the wavelet function:

Figure BDA0003961656260000212
Figure BDA0003961656260000212

选择伸缩因子a,平移因子b,将小波母函数ψ(t)进行伸缩和平移操作,可得小波基函数:Select the scaling factor a and the translation factor b, scale and translate the wavelet mother function ψ(t), and you can get the wavelet basis function:

Figure BDA0003961656260000213
Figure BDA0003961656260000213

按下式对电流信号进行小波变换,得到小波系数Wi(a,b)Perform wavelet transform on the current signal according to the following formula to obtain the wavelet coefficients Wi (a, b):

Figure BDA0003961656260000214
Figure BDA0003961656260000214

其中ψ*(t)是ψ(t)的复共轭。where ψ * (t) is the complex conjugate of ψ(t).

具体的,所述CNN网络包括顺序连接的输入层、卷积层、池化层、全连接层和输出层,所述卷积层为3层,卷积核提取电流时频谱图的特征,所述池化层也有3个,分别将3个卷积层输出数据进行降维;输出层由Softmax模块和分类模块构成。Specifically, the CNN network includes a sequentially connected input layer, a convolution layer, a pooling layer, a fully connected layer and an output layer. The convolution layer has three layers, and the convolution kernel extracts the characteristics of the current spectrum. The pooling layer also has three layers, and the output data of the three convolution layers are respectively reduced in dimension; the output layer is composed of a Softmax module and a classification module.

更具体的,所述卷积层通过公式

Figure BDA0003961656260000215
得到当前神经元
Figure BDA0003961656260000216
式中,Mj为输入到神经元j的向量总数,
Figure BDA0003961656260000217
为前一层输入神经元的特征图;kij l为卷积核的权重;bj为第j种特征图的偏置;σ为ReLU激活函数;More specifically, the convolutional layer is constructed by the formula
Figure BDA0003961656260000215
Get the current neuron
Figure BDA0003961656260000216
Where Mj is the total number of vectors input to neuron j,
Figure BDA0003961656260000217
is the feature map of the input neuron in the previous layer; k ij l is the weight of the convolution kernel; b j is the bias of the jth feature map; σ is the ReLU activation function;

Softmax模块输出Softmax module output

Figure BDA0003961656260000221
Figure BDA0003961656260000221

式中,xj为全连接层的第j个输出,k为Softmax模块输入个数,k=2,则P1、P2为Where xj is the jth output of the fully connected layer, k is the number of inputs to the Softmax module, k = 2, then P1 and P2 are

Figure BDA0003961656260000222
Figure BDA0003961656260000222

P1、P2分别表示输出为y=1和y=0的概率;将概率值P1、P2输入分类模块,在分类模块中计算交叉损失熵函数值L,其中

Figure BDA0003961656260000223
yi为事件标签值,y1=1,y2=0。P1 and P2 represent the probabilities of outputting y=1 and y=0 respectively; the probability values P1 and P2 are input into the classification module, and the cross loss entropy function value L is calculated in the classification module, where
Figure BDA0003961656260000223
yi is the event label value, y1 = 1, y2 = 0.

更具体的,所述CNN网络还包括Inception-v3结构,该结构使用大小为1×n和n×1的滤波器来代替CNN网络中n×n的卷积。More specifically, the CNN network also includes an Inception-v3 structure, which uses filters of size 1×n and n×1 to replace the n×n convolution in the CNN network.

更具体的,所述参数优化模块还用于:设置损失函数Lloss,当CNN网络的损失值L<Lloss,网络训练可靠,将P1、P2中数值较大的标签值作为网络输出;否则表示网络权重分配不当,利用采用粒子群优化算法重新分配权值重复上述过程直至满足网络输出条件得到最优CNN网络参数。More specifically, the parameter optimization module is also used to: set the loss function L loss , when the loss value L of the CNN network < L loss , the network training is reliable, and the label value with a larger value in P1 and P2 is used as the network output; otherwise, it means that the network weight distribution is improper, and the particle swarm optimization algorithm is used to reallocate the weights and repeat the above process until the network output conditions are met to obtain the optimal CNN network parameters.

更具体的,所述粒子群优化算法重新分配权值,包括:More specifically, the particle swarm optimization algorithm reallocates weights, including:

S41、在CNN网络计算出期望值与实际值之间的误差后,每个粒子都将CNN网络的批处理的样本数量batchsize、训练数据丢弃率dropout、卷积核数量Nc、卷积核大小Mc和网络初始偏置bj作为待优化超参数,待优化超参数作为粒子维度;S41. After the CNN network calculates the error between the expected value and the actual value, each particle takes the batch size of samples in the CNN network, the training data discard rate, the number of convolution kernels N c , the convolution kernel size Mc and the network initial bias b j as the hyperparameters to be optimized, and the hyperparameters to be optimized are used as the particle dimensions;

S42、以CNN网络的期望值与实际值之间的误差作为适应度函数,计算每个粒子的适应度值,将n次迭代更新中每个粒子出现过的最优点作为个体最优解Pbest保存,再与整体种群粒子比较,选取全局最优值Gbest保存;S42, using the error between the expected value and the actual value of the CNN network as the fitness function, calculating the fitness value of each particle, saving the best point of each particle in n iterative updates as the individual optimal solution P best , and then comparing it with the particles of the entire population, selecting the global optimal value G best and saving it;

S43、比较粒子的适应度值与个体的最优适应度值,若粒子的适应度值较大,将其替换为个体最优适应度值;S43, comparing the fitness value of the particle with the optimal fitness value of the individual, if the fitness value of the particle is larger, replacing it with the optimal fitness value of the individual;

S44、比较所有粒子的个体最优适应度值与群体全局最优适应度值,若个体最优适应度值较大,则将其替换为全局最优适应度值;S44, comparing the individual optimal fitness values of all particles with the global optimal fitness value of the group, if the individual optimal fitness value is larger, it is replaced by the global optimal fitness value;

S45、更新粒子的速度与位置,返回执行步骤S42;S45, update the speed and position of the particle, and return to execute step S42;

S46、比较当前迭代次数和最大迭代次数的大小,当n<N时,迭代继续;当n>N时,迭代结束,或者达到最小误差时迭代结束,若两个迭代结束条件均不满足则返回步骤S42,否则退出循环得到全局最优适应度值,全局最优适应度值对应的粒子的各参数即为粒子群寻优得到的最优CNN网络参数。S46. Compare the current number of iterations with the maximum number of iterations. When n<N, the iteration continues; when n>N, the iteration ends, or the iteration ends when the minimum error is reached. If both iteration end conditions are not met, return to step S42, otherwise exit the loop to obtain the global optimal fitness value. The parameters of the particles corresponding to the global optimal fitness value are the optimal CNN network parameters obtained by the particle swarm optimization.

以上实施例仅用以说明本发明的技术方案,而非对其限制;尽管参照前述实施例对本发明进行了详细的说明,本领域的普通技术人员应当理解:其依然可以对前述各实施例所记载的技术方案进行修改,或者对其中部分技术特征进行等同替换;而这些修改或者替换,并不使相应技术方案的本质脱离本发明各实施例技术方案的精神和范围。The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (10)

1. GIS switching-on and switching-off state current detection method based on CNN network, characterized in that the method comprises:
the method comprises the following steps: collecting the opening and closing states of a disconnecting link and a grounding switch and corresponding coupling capacitance current data sets in all states of GIS equipment;
step two: preprocessing the acquired current data, and constructing a training set of the network;
step three: constructing a CNN network, wherein the input of the CNN network is a training set, and the output of the CNN network is the opening and closing state of a disconnecting link and a grounding switch;
step four: optimizing CNN network parameters by using a particle swarm optimization algorithm to obtain optimal CNN network parameters;
step five: and setting the CNN network according to the optimal CNN network parameters to obtain the optimal CNN network, acquiring fault current data of a disconnecting link and a grounding switch of the GIS equipment in real time, preprocessing the fault current data, inputting the fault current data into the optimal CNN network, and outputting a GIS switching-on and switching-off state judgment result by using the optimal CNN network.
2. The method for detecting GIS opening and closing state current based on CNN network according to claim 1, wherein the step one includes:
when the GIS equipment is in a hot standby state, the switching conditions of each group of disconnecting link and grounding switch are disconnecting link switching-on and grounding switch switching-off, and the switching state Y of the grounding switch is recorded H ={y 1 H ,y 2 H …y k H …y K H }, simultaneously acquiring a current data set I H ={I 1 H ,I 2 H …I k H …I K H Therein of
Figure FDA0003961656250000011
Representing the kth earth-knife current in a hot standby state;
when the GIS equipment is in a cold standby state, the opening and closing conditions of each group of disconnecting link and earthing switch are disconnecting link and earthing switch, and the opening and closing states Y of the earthing switch and the disconnecting link are recorded C ={y 1 C ,y 2 C …y k C …y K C ,y 1 C' ,y 2 C' …y m C' …y M C' Simultaneously collecting a ground knife current data set I and a knife switch current data set I C ={I 1 C ,I 2 C …I k C …I K C ,I 1 C' ,I 2 C' …I m C' …I M C' Therein of
Figure FDA0003961656250000012
Indicates the kth ground switch current in the cold standby state, < > is present>
Figure FDA0003961656250000021
Indicating the m-th knife switch current in a cold standby state;
when the GIS equipment is in the maintenance state, the switching conditions of each group of disconnecting link and grounding switch are disconnecting link and grounding switch switching, and the switching states of the disconnecting links and the grounding switch are recorded, namely Y R ={y 1 R ,y 2 R …y m R …y M R Simultaneously acquiring a disconnecting link current data set I R ={I 1 R ,I 2 R …I m R …I M R Therein of
Figure FDA0003961656250000022
Indicating the mth boundary knife switch current in the maintenance state.
3. The method for detecting GIS opening and closing state current based on CNN network according to claim 1, wherein the second step comprises:
s21, collecting fault current data of the disconnecting link and the grounding switch, and performing wavelet transformation on a fault current signal to obtain a wavelet coefficient W i (a, b) and a candidate frequency f ins
S22, passing formula
Figure FDA0003961656250000023
A zero matrix is obtained, where (Δ a) k =a k -a k-1 ,Δf=f k -f k-1 ,a k Is the scale factor of the k-th transient component, f k Is the center frequency of the kth transient component, taking k e [0, n a ],f s A signal sampling frequency; from f in S21 ins According to the formula f ins =2 kΔf ·f s /n a Calculating a k value, wherein &>
Figure FDA0003961656250000024
Judging k belongs to [0, n ] a ]Whether it is satisfied, if so, then
Figure FDA0003961656250000025
Repeating the steps for preset times, making the signal thin and clearly showing on the time-frequency diagram,
passing through type
Figure FDA0003961656250000027
Reconstruct the signal and its respective component, wherein>
Figure FDA0003961656250000026
R e The real part is taken. />
4. The method for detecting GIS opening/closing state current based on CNN network according to claim 3, wherein S21 includes:
a mother wavelet function psi (t) is selected such that its Fourier transform psi (omega) satisfies the admissibility conditions of the following wavelet functions
Figure FDA0003961656250000031
Selecting a scaling factor a and a shifting factor b, and performing scaling and shifting operations on the wavelet mother function psi (t) to obtain a wavelet basis function:
Figure FDA0003961656250000032
wavelet transformation is carried out on the current signal according to the following formula to obtain a wavelet coefficient W i (a,b)
Figure FDA0003961656250000033
Wherein psi * (t) is the complex conjugate of ψ (t).
5. The method for detecting GIS switching-on/off state current based on CNN network according to claim 1, wherein CNN network comprises sequentially connected input layer, convolution layer, pooling layer, full-connection layer and output layer, the convolution layer is 3 layers, convolution kernel extracts current time-frequency spectrogram feature, the pooling layer is also 3, 3 convolution layers output data are respectively reduced in dimension; the output layer is composed of a Softmax module and a classification module.
6. The GIS switching-on/off state current detection method based on CNN network of claim 5, characterized in that the convolution layer passes through a formula
Figure FDA0003961656250000034
Obtain the current neuron>
Figure FDA0003961656250000035
In the formula, M j For the total number of vectors input to neuron j, <' >>
Figure FDA0003961656250000036
Is a characteristic diagram of the previous layer of input neurons; k is a radical of formula ij 1 Weight of the convolution kernel; b is a mixture of j Is the bias of the jth profile; σ is a ReLU activation function;
softmax module output
Figure FDA0003961656250000037
In the formula, x j J is the j output of the full connection layer, k is the input number of the Softmax module, and k =2, then P1 and P2 are
Figure FDA0003961656250000041
P1, P2 represent probabilities of outputs of y =1 and y =0, respectively; inputting the probability values P1, P2 into a classification module, and calculating a cross-loss entropy function value L in the classification module, wherein
Figure FDA0003961656250000042
y i Is an event tag value, y 1 =1,y 2 =0。
7. The method of claim 6, wherein the CNN network further comprises an inclusion-v 3 structure that uses filters of 1 × n and n × 1 sizes to replace the convolution of n × n in the CNN network.
8. The GIS switching-on/off state current detection method based on CNN network according to claim 6, characterized by that, the fourth step includes: setting a loss function L loss When the loss value L of the CNN network is less than L loss The network training is reliable, and the label value with a larger value in P1 and P2 is taken as the network output; otherwise, indicating that the network weight is not properly distributed, and redistributing the weight by adopting a particle swarm optimization algorithm to repeat the process until the network output condition is met to obtain the optimal CNN network parameter.
9. The GIS switching-on/off state current detection method based on CNN network of claim 8, wherein the weight redistribution by the particle swarm optimization comprises:
s41, after the error between the expected value and the actual value is calculated by the CNN network, the batch processing sample number batchsize, the training data discarding rate dropout and the convolution kernel number N of the CNN network are calculated by each particle c Size of convolution kernel M c And network initial bias b j The parameters are used as hyper-parameters to be optimized, and the hyper-parameters to be optimized are used as particle dimensions;
s42, calculating the fitness value of each particle by taking the error between the expected value and the actual value of the CNN as a fitness function, and taking the optimal point of each particle in the n times of iterative updating as the individual optimal solution P best Storing, comparing with the whole population particles, and selecting the global optimum value G best Storing;
s43, comparing the fitness value of the particle with the individual optimal fitness value, and replacing the fitness value of the particle with the individual optimal fitness value if the fitness value of the particle is larger;
s44, comparing the individual optimal fitness values of all the particles with the group global optimal fitness value, and replacing the individual optimal fitness value with the global optimal fitness value if the individual optimal fitness value is larger;
s45, updating the speed and the position of the particles, and returning to execute the step S42;
s46, comparing the current iteration times with the maximum iteration times, and when N is less than N, continuing the iteration; and when N is larger than N, finishing iteration or finishing iteration when the minimum error is reached, returning to the step S42 if the two iteration finishing conditions are not met, otherwise, exiting the loop to obtain a global optimal fitness value, wherein each parameter of the particles corresponding to the global optimal fitness value is the optimal CNN network parameter obtained by particle swarm optimization.
10. GIS divide-shut brake state current detection device based on CNN network, its characterized in that, the device includes:
the data acquisition module is used for acquiring the opening and closing states of a disconnecting link and a grounding switch and corresponding coupling capacitance current data sets in all states of the GIS equipment;
the training set construction module is used for preprocessing the acquired current data and constructing a training set of the network;
the network construction module is used for constructing a CNN network, the input of the CNN network is a training set, and the output of the CNN network is the opening and closing states of a disconnecting link and a grounding switch;
the parameter optimization module is used for optimizing the CNN network parameters by using a particle swarm optimization algorithm to obtain optimal CNN network parameters;
and the result output module is used for setting the CNN network according to the optimal CNN network parameters to obtain the optimal CNN network, acquiring fault current data of a disconnecting link and a grounding switch of the GIS equipment in real time, preprocessing the fault current data, inputting the preprocessed data into the optimal CNN network, and outputting a GIS switching-on/off state judgment result by using the optimal CNN network.
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117216673A (en) * 2023-11-08 2023-12-12 国网江西省电力有限公司电力科学研究院 Current transformer monitoring evaluation overhauls platform
CN117805607A (en) * 2024-02-29 2024-04-02 山西漳电科学技术研究院(有限公司) DC level difference matching test method for power plant DC system

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117216673A (en) * 2023-11-08 2023-12-12 国网江西省电力有限公司电力科学研究院 Current transformer monitoring evaluation overhauls platform
CN117216673B (en) * 2023-11-08 2024-03-12 国网江西省电力有限公司电力科学研究院 A current transformer monitoring, evaluation and maintenance platform
CN117805607A (en) * 2024-02-29 2024-04-02 山西漳电科学技术研究院(有限公司) DC level difference matching test method for power plant DC system
CN117805607B (en) * 2024-02-29 2024-05-07 山西漳电科学技术研究院(有限公司) DC level difference matching test method for power plant DC system

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