CN106777633B - Method and device for calculating temperature of switch contact of solid insulation switch cabinet - Google Patents

Abstract

The invention discloses a method and a device for calculating the temperature of a switch contact of a solid insulation switch cabinet. By acquiring multiple sets of sample data in advance, a mathematical model between various influencing factors is established by the partial least square method to determine the temperature of the measurement point and the solid insulation switch. The functional relationship between the temperature of the switch contacts of the cabinet, the sample data contains multiple sets of data of factors affecting the temperature change of the switch contacts, the measurement point is located in the preset range around the switch contact; the current temperature value monitored by the measurement point is obtained ; According to the current temperature value, the temperature value of the switch contact of the solid insulated switchgear is calculated through the functional relationship. The present application dynamically calculates the contact temperature of the circuit breaker based on the partial least squares mathematical modeling method, without considering the physical parameters of the outer insulating layer and the contact material, which facilitates the calculation of the contact temperature. The method has strong versatility, simple implementation and low cost, and can provide a reference for accurately grasping the operating state of the switchgear in real time.

Description

Method and device for calculating switch contact temperature of solid insulated switchgear

technical field

The invention relates to the technical field of electric power systems, in particular to a method and device for calculating the temperature of a switch contact of a solid insulated switchgear.

Background technique

Switchgear is an important equipment in the power system, it is mainly responsible for the current combined with other electrical equipment and the power grid. However, during the long-term operation of the switch cabinet, the contact resistance increases due to the aging of the contacts and poor contact. The increase of the contact resistance causes the local temperature of the switch cabinet to rise. The heating of the contacts will accelerate the aging of the insulation layer, and the fire caused by the overheating of the contacts And power outages are not uncommon. Therefore, the online monitoring of the temperature of the switch contacts of the switch cabinet becomes more important. At present, the research on the contact temperature of switch cabinets generally focuses on the development and improvement of temperature monitoring equipment. At present, there are mainly three operating technologies to monitor the contact temperature in real time. One method is to use the camera and the temperature-indicating wax device. There are many contacts to be monitored inside the switch cabinet, and the monitoring field of view before the camera and the temperature-indicating wax cannot be blocked, which is difficult in some areas with complex structures and narrow spaces. Realize the one-to-one installation of the temperature-indicating wax piece and the camera. The other is to use infrared temperature measurement technology. It obtains temperature data by receiving the infrared radiation of the measured point. However, when placing the temperature measurement probe, it is necessary to pay attention to avoid the cross influence of the optical path. One infrared sensor corresponds to one touch. head. There is also a temperature measurement technology through optical fiber temperature sensor, which is currently the most widely used temperature measurement technology. It has a wide measurement range and high measurement accuracy, but its cost is high, and it is greatly affected by the structure of the switch cabinet, resulting in monitoring temperature. Unreliable.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a method and device for calculating the temperature of a switch contact of a solid insulated switchgear, so as to solve the problems of difficult realization, high cost and unreliable temperature monitoring in the existing real-time monitoring technology of switch contact temperature of a switchgear.

In order to solve the above technical problems, the present invention provides a method for calculating the temperature of a switch contact of a solid insulated switchgear, including:

Obtain multiple sets of sample data in advance, establish a mathematical model between the influencing factors through the partial least squares method, and determine the functional relationship between the temperature of the measurement point and the temperature of the switch contacts of the solid insulated switchgear. The sample data contains multiple sets of Influencing factor data affecting the temperature change of the switch contact, the measurement point is located within a preset range around the switch contact;

Obtain the current temperature value monitored at the measurement point;

According to the current temperature value, the temperature value of the switch contact of the solid insulated switchgear is calculated through the functional relationship.

Optionally, the mathematical model between the influencing factors is established by the partial least squares method, and the functional relationship between the temperature of the measurement point and the temperature of the switch contacts of the solid insulated switchgear is determined, including:

和自变量矩阵

Take the temperature of the measurement point as the dependent variable y, and each influencing factor as the independent variable x ₁ , x ₂ , x ₃ , x ₄ , x ₅ , x ₆ , x ₇ , obtain n groups of sample data, and form a dependent variable matrix Y=[y] _n×1 and independent variable matrix X=[x ₁ x ₂ x ₃ x ₄ x ₅ x ₆ x ₇ ] _n×7 , standardize Y and X to obtain a standardized dependent variable matrix

and the independent variable matrix

Among them, x _ij is the value of the j-th variable of the i-th sample in the matrix X, and y _i represents the i-th sample value in the matrix Y;

Extract the principal components from E ₀ in turn, and implement the regression analysis of the dependent variable to the independent variable, convert it into the regression equation of Y to X, and determine

中的回归系数β₁～β₇。

The regression coefficients β ₁ to β ₇ in .

Optionally, the influencing factors specifically include: x ₁ corresponds to the thickness d of the epoxy resin insulating layer; x ₂ corresponds to the horizontal distance r between the installation position of the thermocouple temperature sensor and the switch contact; x ₃ corresponds to the actual temperature δ of the switch contact ₀ ; x ₄ corresponds to the temperature δ ₁ of the switchgear cabinet; x ₅ corresponds to the ambient temperature δ ₂ where the switch cabinet is located; x ₆ corresponds to the working current i of the busbar connecting the switch contacts; x ₇ corresponds to the volume v of the switch cabinet; y corresponds to The temperature Q of the measuring point.

Optionally, the standardizing processing on Y and X includes:

进行标准化处理，use

standardized,

表示变量x_j的平均值，s_j表示x_j的标准差，

表示y的平均值，s_y表示y的标准差。in,

represents the mean of the variable x _j , s _j represents the standard deviation of x _j ,

represents the mean of y, and s _y represents the standard deviation of y.

Optionally, after the sequential extraction of the principal components from E ₀ , the method further includes:

The contribution degree of the extracted component is calculated, and when the contribution degree is greater than a preset threshold, it is determined that the contribution degree of the extracted component is significant.

Optionally, the obtaining the current temperature value monitored by the measurement point includes:

The current temperature value is monitored in real time by a temperature sensor arranged at the measuring point, which is located on the outer wall of the insulating layer of the switch contact.

Optionally, after calculating the temperature value of the switch contact of the solid insulated switchgear through the functional relationship, the method further includes:

The calculated temperature value is displayed to the user.

The present invention also provides a device for calculating the temperature of a switch contact of a solid insulated switchgear, comprising:

The model building module is used to obtain multiple sets of sample data in advance, establish a mathematical model between the influencing factors through the partial least squares method, and determine the functional relationship between the temperature of the measurement point and the temperature of the switch contacts of the solid insulated switchgear. The sample data includes a plurality of groups of influencing factor data affecting the temperature change of the switch contact, and the measurement point is located within a preset range around the switch contact;

The current temperature acquisition module is used to acquire the current temperature value monitored at the measurement point;

The calculation module is configured to calculate the temperature value of the switch contact of the solid insulated switchgear through the functional relationship according to the current temperature value.

The method and device for calculating the temperature of the switch contacts of the solid insulated switchgear provided by the present invention obtains multiple groups of sample data in advance, and establishes a mathematical model between various influencing factors through the partial least squares method, so as to determine the temperature of the measurement point and the solid insulation switchgear. The functional relationship between the temperature of the switch contacts, the sample data contains multiple sets of data of influencing factors that affect the temperature change of the switch contacts, the measurement point is located within the preset range around the switch contact; the current temperature value monitored by the measurement point is obtained; According to the current temperature value, the temperature value of the switch contact of the solid insulated switchgear is calculated through a functional relationship. The present application dynamically calculates the contact temperature of the circuit breaker based on the partial least squares mathematical modeling method, without considering the physical parameters of the outer insulating layer and the contact material, which facilitates the calculation of the contact temperature. The method has strong versatility, simple implementation and low cost, and can provide a reference for accurately grasping the operating state of the switchgear in real time.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions of the prior art, the following will briefly introduce the accompanying drawings used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only For some embodiments of the present invention, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative efforts.

1 is a flowchart of a specific embodiment of a method for calculating the temperature of a switch contact of a solid insulated switchgear provided by the present invention;

Fig. 2 is a flow chart of another specific embodiment of the method for calculating the temperature of switch contacts of a solid insulated switchgear provided by the present invention;

Figure 3 is a flowchart of an algorithm for establishing a functional relationship between a measurement point and a switch contact by partial least squares;

Figure 4 is a schematic diagram of the installation position of each temperature sensor;

FIG. 5 is a structural block diagram of a device for calculating the temperature of a switch contact of a solid insulated switchgear provided by an embodiment of the present invention.

Detailed ways

In order to make those skilled in the art better understand the solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only some, but not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

A flow chart of a specific embodiment of the method for calculating the temperature of a switch contact of a solid insulated switchgear provided by the present invention is shown in FIG. 1 , and the method includes:

Step S101: Acquire multiple sets of sample data in advance, establish a mathematical model between the influencing factors through the partial least squares method, and determine the functional relationship between the temperature of the measurement point and the temperature of the switch contacts of the solid insulated switchgear, the sample data Contains multiple groups of data of influencing factors affecting the temperature change of the switch contact, and the measurement point is located within a preset range around the switch contact;

Step S102: obtaining the current temperature value monitored by the measuring point;

Step S103: According to the current temperature value, calculate the temperature value of the switch contact of the solid insulated switchgear through the functional relationship.

The method for calculating the temperature of the switch contacts of the solid insulated switchgear provided by the present invention obtains multiple groups of sample data in advance, and establishes a mathematical model among various influencing factors through the partial least squares method, so as to determine the temperature of the measurement point and the switch of the solid insulated switchgear. The functional relationship between the temperatures of the contacts, the sample data contains multiple sets of data of factors affecting the temperature change of the switch contacts, the measurement point is located within the preset range around the switch contact; the current temperature value monitored by the measurement point is obtained; Temperature value, the temperature value of the switch contact of the solid insulated switchgear is calculated through the functional relationship. The present application dynamically calculates the contact temperature of the circuit breaker based on the partial least squares mathematical modeling method, without considering the physical parameters of the outer insulating layer and the contact material, which facilitates the calculation of the contact temperature. The method has strong versatility, simple implementation and low cost, and can provide a reference for accurately grasping the operating state of the switchgear in real time.

On the basis of the above embodiment, the mathematical model between the influencing factors is established by the partial least squares method, and the process of determining the functional relationship between the temperature of the measurement point and the temperature of the switch contact of the solid insulated switchgear can be specifically as follows:

和自变量矩阵

Take the temperature of the measurement point as the dependent variable y, and each influencing factor as the independent variable x ₁ , x ₂ , x ₃ , x ₄ , x ₅ , x ₆ , x ₇ , obtain n groups of sample data, and form a dependent variable matrix Y=[y] _n×1 and independent variable matrix X=[x ₁ x ₂ x ₃ x ₄ x ₅ x ₆ x ₇ ] _n×7 , standardize Y and X to obtain a standardized dependent variable matrix

and the independent variable matrix

Among them, x _ij is the value of the j-th variable of the i-th sample in the matrix X, and y _i represents the i-th sample value in the matrix Y;

Extract the principal components from E ₀ in turn, and implement the regression analysis of the dependent variable to the independent variable, convert it into the regression equation of Y to X, and determine

中的回归系数β₁～β₇。

The regression coefficients β ₁ to β ₇ in .

In this embodiment, the partial least squares algorithm is used to calculate the temperature of the switch contacts of the switch cabinet in real time. After the switch contacts are heated, the heat will be transferred to the outer wall of the insulating layer through the convection of the air inside the insulating layer and the conduction of the wall of the insulating layer, and make it temperature rises. According to the functional relationship between the temperature rise of the outer wall of the insulating layer and the switch contacts, the latter can be calculated according to the former. The insulating material wrapped around the inner conductor of the switch cabinet is epoxy resin, and a thermocouple sensor that is easy to assemble and inexpensive to measure is used to measure the temperature of the outer skin of the insulating layer near the switch contact, and then use the functional relationship obtained from the experimental data:

In this embodiment, the influencing factors specifically include: x ₁ corresponds to the thickness d of the epoxy resin insulating layer; x ₂ corresponds to the horizontal distance r between the installation position of the thermocouple temperature sensor and the switch contact; x ₃ corresponds to the actual temperature δ ₀ of the switch contact; x ₄ corresponds to the temperature δ ₁ of the switchgear cabinet; x ₅ corresponds to the ambient temperature δ ₂ of the switch cabinet; x ₆ corresponds to the working current i of the connecting switch contact busbar; x ₇ corresponds to the specific cabinet volume v of the switch cabinet; y corresponds to the measurement point temperature Q.

Taking the above influencing factors as an example, and referring to FIG. 2 , another specific implementation of the method for calculating the temperature of the switch contacts of the solid insulated switchgear will be further elaborated.

Step S201: acquiring experimental data;

Fix the temperature sensor near the switch contact, the temperature Q at the measurement point of the temperature sensor and the thickness d of the epoxy resin insulating layer, the horizontal distance r between the installation position of the thermocouple and the switch contact, the actual temperature of the switch contact δ ₀ , the switch The cabinet body temperature δ ₁ , the ambient temperature δ ₂ of the switch cabinet, the working current i of the switch contact busbar, and the specific cabinet volume v of the switch cabinet are closely related. Place the switchgear in different external environments and record the ambient temperature, conduct a simulation experiment on the switchgear contacts in the laboratory, and use a heater with a power of 1000w to heat the contacts to simulate the heat source that causes the contacts to overheat. The computer is connected to the Internet, and the intelligent control mode is adopted to accurately control the heating temperature. Several temperature control experiments are performed and the temperature of the heating contact is recorded. At the same time, during each temperature control experiment, the positions of other temperature sensors in the cabinet are constantly changed to obtain the temperature of each factor. Several sets of experimental data. A specific embodiment of the operation mode and data is shown in Table 1.

Table 1

Wherein, operation mode 1, take a switch cabinet experiment, measure the thickness of the insulating layer, denoted as x ₁₁ ; install the temperature sensor 1 at any position of the insulating layer outside the contact, and measure the horizontal distance of the sensor from the contact, denoted as x ₂₁ ; after all the sensors are installed, the heater will heat the contacts, set the initial heating temperature through the computer, which is recorded as the contact temperature x ₃₁ ; install the temperature sensor 2 in the cabinet at the ventilation opening of the switch cabinet, and measure the temperature of the cabinet , denoted as x ₄₁ ; put the switchgear in an indoor environment with adjustable temperature, and the indoor ambient temperature is gradually adjusted from low temperature to high temperature to obtain different ambient temperatures, and the initial setting ambient temperature x ₅₁ is recorded; the experiment measures the busbar work Current, denoted as x ₆₁ ; measuring cabinet volume, denoted as x ₇₁ ; temperature sensor 1 measuring the outer skin temperature of the insulating layer, denoted as Y ₁ . The above experimental measurement data are used as the first group of data.

Operation mode 2, take another switch cabinet experiment, measure the thickness of the insulating layer x ₁₂ ; change the position of the temperature sensor 1 to wrap the insulating layer on the contact, and measure the horizontal distance x ₂₂ of the sensor from the contact point; adjust the heater temperature by computer After the heating contact is in a steady state, it is recorded as the contact temperature x ₃₂ ; the temperature sensor 2 is installed at the ventilation opening of the switch cabinet, and the temperature of the cabinet is measured x ₄₂ ; the ambient temperature of the switch cabinet is changed x ₅₂ ; Current x ₆₂ ; measuring cabinet volume x ₇₂ ; temperature sensor 1 measuring the outer skin temperature Y ₂ of the insulating layer. The above experimental measurement data are used as the second group of data.

Operation mode n, and so on, repeat the above steps to linearly adjust the heater temperature to obtain several groups of contact heat source temperature rise experimental data.

Step S202: extracting n groups of sample data, adopting partial least squares modeling, and determining the coefficients in the functional relationship;

和自变量矩阵

标准化处理方法为：As shown in the algorithm flow chart of establishing the functional relationship between the measuring point and the switch contact by partial least squares in Fig. 3, the temperature of the measuring point is taken as the dependent variable y, and each influencing factor is taken as the independent variable x ₁ , x ₂ , x ₃ , x ₄ , x ₅ , x ₆ , x ₇ , obtain n groups of sample data from the above experimental data, and form a dependent variable matrix Y=[y] _n×1 and an independent variable matrix X=[x ₁ x ₂ x ₃ x ₄ x ₅ x ₆ x ₇ ] _n×7 , normalize Y and X to get a standardized dependent variable matrix

and the independent variable matrix

The standardized processing method is:

表示变量x_j的平均值，s_j表示x_j的标准差，y_i表示矩阵Y中第i个样本值，

表示y的平均值，s_y表示y的标准差；Among them, x _ij represents the value of the j-th variable of the i-th sample in the matrix X,

represents the mean value of variable x _j , s _j represents the standard deviation of x _j , y _i represents the ith sample value in matrix Y,

represents the mean of y, and s _y represents the standard deviation of y;

Extract the first principal component from E ₀ t ₁ =E ₀ w ₁ , where w ₁ is the weight vector of t ₁ , where

In the formula, E ₀₁ ～E ₀₇ represent the column vector of E ₀ , and r(x ₁ , y)～r(x ₇ , y) represent the correlation coefficient between the independent variable and the dependent variable;

Then calculate the regression coefficient matrix P ₁ of E ₀ to t ₁

Calculate the residual matrix E ₁ of the regression equation

E ₁ =E ₀ -t ₁ P ₁ ^T

Calculate the contribution of the extracted components, let y _i be the original data, _yi ' is the fitted value of the i-th sample point after using all the sample points and t ₁ regression modeling, and y _i ″ is deleted during modeling Sample point i, and after modeling t ₁ regression, use the fitted value of y _i calculated by this model

时，提取成分t₁的贡献度是显著的，接下来进行第二成分的提取；否则停止计算。when

, the contribution of the extracted component t ₁ is significant, and the second component is extracted next; otherwise, the calculation is stopped.

因为E₁不是标准化矩阵，按如下方法计算w₂ Extract the second component t ₂ from E ₁ , replace E ₀ with E ₁ , calculate the weight of t ₂ with the above method

Since E1 is not _a normalized matrix, calculate _w2 as follows

t ₂ =E ₁ w ₂

In the formula, P ₂ is the regression coefficient matrix of E ₁ to t ₂ , E ₂ is the residual matrix of the regression equation, and cov(E ₁₁ ,y)～cov(E ₁₇ ,y) represents the relationship between E ₁₁ ～E ₁₇ and y respectively. Covariance.

当时，说明提取成分t₂的贡献度是显著的，接下来进行第三成分的提取；否则停止计算。and calculate the contribution of the extracted components

when , it indicates that the contribution of the extracted component t ₂ is significant, and the third component is extracted next; otherwise, the calculation is stopped.

By analogy, continue the above steps, extract the principal components in the residual matrix, and calculate the contribution of the extracted components; if m components are finally obtained (m<7), then implement the regression of F ₀ on the m extracted components:

F ₀ =r ₁ t ₁ +r ₂ t ₂ +...+r _m t _m

Since each extracted component is a linear combination of _E0 , so

Carry out regression analysis of the dependent variable on the independent variable, record

则标准化变量y^*关于

的回归方程为：

then the standardized variable y ^* about

The regression equation of is:

Then through the inverse process of standardization, the regression equation of y about x ₁ ~ x ₅ is obtained

y=β ₁ x ₁ +β ₂ x ₂ +β ₃ x ₃ +β ₄ x ₄ +β ₅ x ₅ +β ₆ x ₆ +β ₇ x ₇

Then the independent variable of the switch contact temperature:

Among them, x ₁ is the thickness d of the epoxy resin insulating layer; x ₂ is the horizontal distance r between the installation position of the thermocouple temperature sensor and the switch contact; x ₃ is the actual temperature of the switch contact δ ₀ ; x ₄ is the temperature of the switch cabinet δ ₁ ; x ₅ is the ambient temperature δ ₂ where the switch cabinet is located; x ₆ is the working current i of the connecting switch contact busbar; x ₇ is the specific cabinet volume v of the switch cabinet; y is the temperature Q of the measuring point; β ₁ ~ β ₇ is the determined correlation coefficient in the functional relationship.

Step S203: Position each temperature sensor, and determine each measurement parameter x ₁ , x ₂ , x ₃ , x ₄ , x ₅ , x ₆ , and x ₇ ;

Step S204: the temperature sensor monitors the real-time temperature, and obtains the current temperature value monitored by each measurement point;

Step S205: Calculate the temperature value of the switch contact of the solid insulated switchgear according to the functional relationship;

Step S206: Display the calculated temperature value to the user.

In the actual measurement process, the specific embodiment only needs to determine the installation position of each temperature sensor, fix the temperature sensor 1 near the grounding point of the outer wall of the insulating layer, ensure safe electrical insulation strength, and connect the determined temperature of the switch contact with the outer wall of the insulating layer. The function relationship corresponding to the temperature of the measuring point is written into the program, and the temperature sensor 1 transmits the monitored data to the cloud computing module, and the processor can output the corresponding contact temperature and transmit it to the display terminal of the low-voltage instrument, so that the contact temperature can be realized. online monitoring. The schematic diagram of the installation position of each temperature sensor is shown in Figure 4.

In the embodiment of the present invention, the distance between the measuring point and the contact and the real-time surface temperature of the insulating layer are used as basic parameters, the external environment of the insulating layer and other factors are considered, and relevant data are measured by experiments. The mathematical model can directly calculate the temperature of the switch contacts in real time. , and is not affected by the physical parameters of the material of the insulating layer itself. The calculation method of the embodiment of the present invention has strong versatility, and is suitable for the calculation of the switch contact temperature of any solid insulating material switch cabinet in various external environments; and the implementation is simple, and only needs to install a temperature sensor on the outer wall of the insulation layer of the switch contact during online measurement. The contact temperature can be calculated through the trained functional relationship and displayed in real time through the instrument terminal. In addition, the mathematical modeling method based on partial least squares does not need to consider the physical parameters of the outer insulating layer and the contact material when dynamically calculating the contact temperature of the circuit breaker, which facilitates the calculation of the contact temperature. Therefore, this method can provide a reference for accurately grasping the operating status of the switchgear in real time.

The following describes the device for calculating the temperature of the switch contacts of the solid insulated switchgear provided by the embodiments of the present invention. The device for calculating the temperature of the switch contacts of the solid insulated switchgear described below and the method for calculating the temperature of the switch contacts of the solid insulated switchgear described above are mutually compatible. corresponding reference.

5 is a structural block diagram of a device for calculating the temperature of a switch contact of a solid insulated switchgear provided by an embodiment of the present invention. Referring to FIG. 5, the device for calculating the temperature of a switch contact of a solid insulated switchgear may include:

The model building module 100 is used to obtain multiple sets of sample data in advance, establish a mathematical model between various influencing factors through the partial least square method, and determine the functional relationship between the temperature of the measurement point and the temperature of the switch contacts of the solid insulated switchgear, The sample data includes a plurality of groups of influencing factor data affecting the temperature change of the switch contact, and the measurement point is located within a preset range around the switch contact;

A current temperature acquisition module 200, configured to acquire the current temperature value monitored at the measurement point;

The calculation module 300 is configured to calculate the temperature value of the switch contact of the solid insulated switchgear through the functional relationship according to the current temperature value.

The device for calculating the temperature of a switch contact of a solid insulated switchgear in this embodiment is used to implement the aforementioned method for calculating the temperature of a switch contact of a solid insulated switchgear. Therefore, the specific implementation of the device for calculating the temperature of a switch contact of a solid insulated switchgear can be found in the previous section. The embodiment part of the method for calculating the temperature of the switch contacts of the solid insulated switchgear, for example, the model establishment module 100, the current temperature acquisition module 200, and the calculation module 300 are respectively used to realize step S101 in the above method for calculating the temperature of the switch contacts of the solid insulated switchgear , S102 , and S103 . Therefore, for the specific implementation, reference may be made to the descriptions of the corresponding partial embodiments, and details are not repeated here.

The device for calculating the switch contact temperature of the solid insulated switchgear provided by the present invention obtains multiple groups of sample data in advance, and establishes a mathematical model between various influencing factors through the partial least squares method, so as to determine the temperature of the measurement point and the switch of the solid insulated switchgear. The functional relationship between the temperatures of the contacts, the sample data contains multiple sets of data of factors affecting the temperature change of the switch contacts, the measurement point is located within the preset range around the switch contact; the current temperature value monitored by the measurement point is obtained; Temperature value, the temperature value of the switch contact of the solid insulated switchgear is calculated through the functional relationship. The present application dynamically calculates the contact temperature of the circuit breaker based on the partial least squares mathematical modeling method, without considering the physical parameters of the outer insulating layer and the contact material, which facilitates the calculation of the contact temperature. The method has strong versatility, simple implementation and low cost, and can provide a reference for accurately grasping the operating state of the switchgear in real time.

The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments may be referred to each other. As for the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant part can be referred to the description of the method.

Professionals may further realize that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two, in order to clearly illustrate the possibilities of hardware and software. Interchangeability, the above description has generally described the components and steps of each example in terms of functionality. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Skilled artisans may implement the described functionality using different methods for each particular application, but such implementations should not be considered beyond the scope of the present invention.

The steps of a method or algorithm described in conjunction with the embodiments disclosed herein may be directly implemented in hardware, a software module executed by a processor, or a combination of the two. A software module can be placed in random access memory (RAM), internal memory, read only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other in the technical field. in any other known form of storage medium.

The method and device for calculating the temperature of the switch contacts of the solid insulated switchgear provided by the present invention are described above in detail. The principles and implementations of the present invention are described herein by using specific examples, and the descriptions of the above embodiments are only used to help understand the method and the core idea of the present invention. It should be pointed out that for those skilled in the art, without departing from the principle of the present invention, several improvements and modifications can also be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims (8)

1. A method for calculating the temperature of a switch contact of a solid insulation switch cabinet is characterized by comprising the following steps:

obtaining multiple groups of sample data in advance, establishing a mathematical model among all influence factors through a partial least square method, and determining a functional relation between the temperature of a measuring point and the temperature of a switch contact of a solid insulation switch cabinet, wherein the sample data comprises multiple groups of influence factor data influencing the temperature change of the switch contact, and the measuring point is located in a preset range around the switch contact; the function relation is

Wherein x is₃Corresponding to the actual temperature, x, of the switch contact₁、x₂、x₄、x₅、x₆、x₇Corresponding to the influencing factor, y corresponds to the temperature of the measuring point, β₁To β₇Is a regression coefficient;

acquiring a current temperature value monitored by the measuring point;

and calculating the temperature value of the switch contact of the solid insulation switch cabinet according to the current temperature value and the functional relation.

2. The method of claim 1, wherein the mathematical model is established between the influencing factors by a partial least squares method, and the determining of the functional relationship between the temperature of the measurement point and the temperature of the switch contact of the solid insulated switchgear comprises:

taking the temperature of the measuring point as a dependent variable y and taking each influencing factor as an independent variable x₁、x₂、x₃、x₄、x₅、x₆、x₇Acquiring n groups of sample data, and forming a dependent variable matrix Y ═ Y]_n×1And the argument matrix X ═ X₁x₂x₃x₄x₅x₆x₇]_n×7Normalizing Y and X to obtain normalized dependent variable matrix

And independent variable matrix

Wherein x is_ijIs the value of the jth variable, y, for the ith sample in the matrix X_iRepresenting the ith sample value in matrix Y;

from E₀Sequentially extracting principal components, performing regression analysis of dependent variable to independent variable, converting into regression equation of Y to X, and determining

The regression coefficient β in₁～β₇。

3. The method for calculating the switch contact temperature of the solid insulated switchgear according to claim 2, wherein the influencing factors specifically include: x is the number of₁Corresponding to the thickness d of the epoxy resin insulating layer; x is the number of₂Distance switch contact corresponding to installation position of thermocouple temperature sensorR; x is the number of₃Corresponding to the actual temperature delta of the switch contacts₀；x₄Corresponding to the temperature delta of the switch cabinet₁；x₅Corresponding to the environment temperature delta of the switch cabinet₂；x₆Working current i corresponding to the bus of the connecting switch contact; x is the number of₇Corresponding to the cabinet volume v of the switch cabinet; y corresponds to the temperature Q of the measurement point.

4. The method for calculating the switch contact temperature of the solid insulated switchgear according to claim 2, wherein the normalizing Y and X comprises:

by using

The standardized treatment is carried out, and the standard treatment is carried out,

wherein,

represents the variable x_jAverage value of (1), s_jDenotes x_jThe standard deviation of (a) is determined,

denotes the average value of y, s_yThe standard deviation of y is indicated.

5. The method for calculating the temperature of the switch contact of the solid insulated switchgear cabinet according to claim 4, wherein the slave E is₀After the main components are sequentially extracted, the method also comprises the following steps:

calculating the contribution degree of the extracted components, and judging that the contribution degree of the extracted components is significant when the contribution degree is greater than a preset threshold value.

6. The method for calculating the switch contact temperature of the solid insulated switchgear cabinet according to any one of claims 1 to 5, wherein the obtaining the current temperature value monitored by the measurement point comprises:

and monitoring the current temperature value in real time through a temperature sensor arranged at the measuring point, wherein the measuring point is positioned on the outer wall of the insulating layer of the switch contact.

7. The method for calculating the temperature of the switch contact of the solid insulated switchgear according to claim 6, wherein after calculating the temperature value of the switch contact of the solid insulated switchgear through the functional relationship, the method further comprises:

and displaying the calculated temperature value to a user.

8. A solid insulated switchgear switch contact temperature calculation device, comprising:

the model establishing module is used for acquiring a plurality of groups of sample data in advance, establishing a mathematical model among all influence factors through a partial least square method, and determining a functional relation between the temperature of a measuring point and the temperature of a switch contact of a solid insulation switch cabinet, wherein the sample data comprises a plurality of groups of influence factor data influencing the temperature change of the switch contact, and the measuring point is positioned in a preset range around the switch contact; the function relation is

Wherein x is₃Corresponding to the actual temperature, x, of the switch contact₁、x₂、x₄、x₅、x₆、x₇Corresponding to the influencing factor, y corresponds to the temperature of the measuring point, β₁To β₇Is a regression coefficient;

the current temperature acquisition module is used for acquiring a current temperature value monitored by the measurement point;

and the calculation module is used for calculating the temperature value of the switch contact of the solid insulation switch cabinet according to the current temperature value and the functional relation.

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