Intelligent transformer system with fault self-diagnosis and power transmission self-regulation functions

Abstract

The present invention relates to an intelligent transformer system with fault self-diagnosis and power transmission self-regulation functions, including an intelligent analysis system, a data server and a collection terminal device, wherein the output end of the collection terminal device is connected to the intelligent analysis service system through the data server; the collection terminal device is provided with a power supply interface, an optical fiber flange interface, a current collection port, a voltage collection port, an external temperature collection port and an internal temperature collection port. The advantages of the present invention are: it can provide operating temperature distribution data of power transformer windings, and provide data support for operating transformer system faults, and a new type of power transformer and operation and maintenance whose capacity can be dynamically regulated in real time. It provides effective support for reducing costs and increasing efficiency of power systems and rationally regulating the transmission of power grid energy.

Description

Technical Field

[0001] The invention relates to an intelligent transformer system with fault self-diagnosis and transmission power self-regulation functions, and relates to the field of transformers. Background Art

[0002] Power transformers are one of the most important power equipment in the power system and the core primary equipment in the power transmission and distribution link. Once a power transformer fails and is damaged, the economic losses and negative social impacts are huge. In particular, with the continuous increase in transmission capacity in recent years, the voltage level and capacity of power transformers are getting larger and larger, and the transparency of the operating status of power transformers is becoming more and more meaningful. Existing power transformers can give real-time evaluation of the health status of transformers through physical signal monitoring such as temperature, dissolved gas, partial discharge, and ultra-high frequency. However, the only method of feedback information from the power industry on-site that is more accurate in evaluating the insulation status of transformers is the detection of dissolved gas. Other methods have various limitations and poor accuracy. Placing optical fiber temperature sensors inside the transformer to monitor the temperature and respond to transformer failures is a more accurate fault identification method. From the retrievable papers and patents, there are also many reports on placing optical fibers in transformers. However, most of the current methods only provide temperature data without further analysis methods, and the temperature monitoring technology of various transformers does not provide substantial help for the operation and maintenance of power systems. The present invention proposes a transformer operation fault self-diagnosis and transformer real-time capacity control technology based on transformer winding holographic temperature imaging technology, which provides an intelligent technical means for reducing costs and increasing efficiency of power systems and rationally regulating the transmission of power grid energy. Summary of the invention

[0003] In order to overcome the defects of the prior art, the present invention provides an intelligent transformer system with fault self-diagnosis and power transmission self-regulation functions. The technical solution of the present invention is:

[0004] An intelligent transformer system with fault self-diagnosis and power transmission self-regulation functions, comprising an intelligent analysis system, a data server and a collection terminal device, wherein the output end of the collection terminal device is connected to the intelligent analysis service system through the data server; the intelligent analysis system comprises a transformer winding line temperature data collection and storage module, a winding temperature data holographic presentation module and a transformer load capacity real-time calculation and display module; the transformer winding line temperature data collection and storage module is used for temperature collection and storage; the winding temperature data holographic presentation module is used for temperature holographic data presentation; the transformer load capacity real-time calculation and display module is used for real-time regulation of transformer load capacity, and real-time calculation and display of residual load margin; a power supply interface, an optical fiber flange interface, a current collection port, a voltage collection port, an external temperature collection port and an internal temperature collection port are arranged on the collection terminal device, and a 220V AC power supply, the fiber optic flange interface is connected to the built-in temperature measuring fiber of the transformer, a current transformer is installed at the current acquisition port, a voltage transformer is installed at the voltage acquisition port, an outer surface temperature sensor is installed at the external temperature acquisition port, and an internal medium temperature sensor is installed at the internal temperature acquisition port; the built-in temperature measuring fiber comprises an insulating paper tape, a temperature measuring component and a winding copper wire core, the outer side of the winding copper wire core is coated with an insulating paper tape, a temperature measuring component is preset at the inner center of the winding copper wire core, the temperature measuring component measures the temperature value of the contact surface between the winding copper wire core and the insulating paper tape, the temperature measuring components are evenly spaced on the winding copper wire core, and the full length range of the transformer winding is monitored in real time.

[0005] The core of the transformer winding is equipped with a point-type or distributed optical fiber temperature sensor to directly measure the temperature of the winding conductor.

[0006] The temperature value of the transformer winding conductor is holographically described using cylindrical coordinates with time variables. The transformer winding is a cylindrical structure formed by spiral winding along the iron core. The line connecting the geometric centers of the planes where the windings of each layer are located is defined as the Z axis. The transformer winding temperature T can be expressed as: T = f(t, θ, r, z) using the cylindrical coordinate system, where t is time, θ is the angle value in the cylindrical coordinate system; r is the winding radius; z represents the longitudinal position of the winding, and the coordinate corresponding to the bottom of the transformer winding is the origin, that is, z = 0; because the size of each winding of the transformer is fixed, the radius r in the cylindrical coordinate system is a constant value, and the winding temperature T can be simplified as: T = f(t, θ, z); because the transformer winding generally has multiple phases, and each phase winding is composed of a high-voltage winding and a low-voltage winding, the winding temperature is further expressed as: T i,j =f(t,θ,z), where i=1,2,3 represent the three-phase windings A, B, and C respectively, j=1 represents the low-voltage winding, and j=2 represents the high-voltage winding.

[0007] The data measured by the optical fiber temperature sensor is the winding conductor temperature that can directly evaluate the thermal state of the transformer. The built-in optical fiber temperature sensor of the winding conductor can measure the transformer winding conductor temperature data set in real time, and all temperature data are converted into temperature data according to the temperature T. i,j The function constructs a temperature distribution cloud diagram of the transformer winding.

[0008] The relative temperature change gradient parameter is used as the fault parameter; assuming that the temperature value of a point on the winding is T0, the temperature values ​​of the upper left, upper, upper right, right, lower left, lower right, lower left, lower left, and left positions are selected as T1, T2, T3, T4, T5, T6, T7, and T8 respectively; then the gradient coefficient in the time Δt range is defined as:

[0009] η=(T1-T0) / Δt+(T2-T0) / Δt+(T3-T0) / Δt+(T4-T0) / Δt+(T5-T0) / Δt+(T6-T0) / Δt+(T7-T0) / Δt+(T8-T0) / Δt; the η value is the initial setting value. When the real-time value is greater than the initial setting value, a high temperature fault warning is issued.

[0010] The transformer operation load control method is based on the transformer winding conductor holographic temperature data value and the transformer real-time power value obtained after being calculated by the analysis module. The specific implementation process is as follows: (1) Each phase winding of the transformer is divided into three sections according to the longitudinal parameter z. If the highest point of the winding corresponds to Zmax, the first section is [0, Zmax / 3], the second section is [Zmax / 3, 2Zmax / 3], and the third section is [2Zmax / 3, Zmax].

[0011] (2) Scanning the holographic temperature field data of the three-phase winding of the transformer in sections respectively, and obtaining the temperature maximum value corresponding to each section in the temperature body of each phase winding;

[0012] (3) Through the formula T i,j =f(t,θ,z) to obtain the position parameters of each phase winding corresponding to the maximum temperature value of the three sections, and establish a database of the relationship between the transformer winding current, voltage and temperature, angle and height;

[0013] (4) Compare the obtained temperature value with the temperature threshold. When the obtained temperature value is greater than or equal to the temperature threshold, the system locks the voltage and current values ​​to determine the maximum load of the transformer. (5) Based on the real-time measured temperature value, the residual load that can be applied to the transformer is calculated.

[0014] The capacity margin of the operating transformer is dynamically calculated based on the conductor winding temperature data. The specific calculation method is as follows: obtain the highest temperature value from the Ti,j winding conductor temperature and record it as T(max), and the medium ambient temperature is Ten; store the T(max) value every 30 minutes and record it as: T(max)(time), and store Ten(time) and the corresponding transformer capacity Pow(time) at the same time; find out the value with a difference of less than 10% between Ten(time) and Ten in real time, take out the time mark, and then compare the real-time T(max) with the maximum value in T(max)(time), find out T(max)(time), and record the Pow(time) corresponding to the moment as the remaining amount value.

[0015] The advantages of the present invention are: it can provide the operating temperature distribution data of the power transformer winding, provide data support for the operating transformer system failure, and provide a new type of power transformer and operation and maintenance whose capacity can be dynamically adjusted in real time. It can provide effective support for reducing costs and increasing efficiency of the power system and reasonably regulating the transmission of power grid energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the main structure of the present invention.

[0017] Figure 2 yes Figure 1 Cross-sectional view of the built-in temperature measurement optical fiber.

[0018] Figure 3 It is a schematic diagram of an embodiment of the transformer temperature holographic image of the present invention.

[0019] Figure 4 yes Figure 1 Schematic diagram of the structure of the intelligent analysis system. DETAILED DESCRIPTION

[0020] The present invention will be further described below in conjunction with specific embodiments, and the advantages and features of the present invention will become clearer as the description proceeds. However, these embodiments are exemplary only and do not constitute any limitation to the scope of the present invention. It should be understood by those skilled in the art that the details and forms of the technical solution of the present invention may be modified or replaced without departing from the spirit and scope of the present invention, but these modifications and replacements all fall within the scope of protection of the present invention.

[0021] See also Figures 1 to 4The present invention relates to an intelligent transformer system with fault self-diagnosis and power transmission self-regulation functions, comprising an intelligent analysis system 1, a data server 2 and a collection terminal device 3, wherein the output end of the collection terminal device 3 is connected to the intelligent analysis service system 1 through the data server 2; the intelligent analysis system 1 comprises a transformer winding line temperature data collection and storage module 13, a winding temperature data holographic presentation module 14 and a transformer load capacity real-time calculation and display module 15; the transformer winding line temperature data collection and storage module 13 is used for temperature collection and storage; the winding temperature data holographic presentation module 14 is used for temperature holographic data presentation; the transformer load capacity real-time calculation and display module 15 is used for real-time regulation of transformer load capacity and real-time calculation and display of residual load margin; a power supply interface, an optical fiber flange interface, a current collection port, a voltage collection port, an external temperature collection port and an internal temperature collection port are arranged on the collection terminal device 3, and a 220V AC power supply 4, the fiber optic flange interface is connected to the built-in temperature measuring fiber 5 of the transformer, a current transformer 6 is installed at the current acquisition port, a voltage transformer 7 is installed at the voltage acquisition port, an outer surface temperature sensor 8 is installed at the external temperature acquisition port, and an internal medium temperature sensor 9 is installed at the internal temperature acquisition port; the built-in temperature measuring fiber includes an insulating paper tape 10, a temperature measuring component 11 and a winding copper wire core 12, the outer side of the winding copper wire core 12 is coated with an insulating paper tape 10, and the temperature measuring component 11 is pre-set at the center of the winding copper wire core 12, the temperature measuring component measures the temperature value of the contact surface between the winding copper wire core and the insulating paper tape 10, and the temperature measuring components are distributed at equal intervals on the winding copper wire core 12, and the full length range of the transformer winding is monitored in real time. This structure can directly measure the temperature of the winding copper wire during operation of the transformer, avoiding the problem of inaccurate measurement of the temperature of the inner insulation layer caused by temperature measurement on the outside of the insulating paper tape. Compared with the existing method of laying optical fiber sensors on the surface of transformer windings, the optical fiber temperature sensor is directly placed inside the copper wire core of the winding. The measured temperature value avoids the heat dissipation of oil flow and the radiation interference of heat sources around the measurement area, and can accurately measure the temperature value of the contact surface between the copper wire core of the winding and the oil-paper insulation.

[0022] The temperature measuring component 11 is a point optical fiber temperature sensor or a distributed temperature measuring optical fiber.

[0023] The winding of the transformer is a cylindrical structure, with the straight line where the geometric center of each layer of winding is located as the Z axis. The transformer winding temperature T can be expressed as: T = f(t, θ, z) using the cylindrical coordinate system, where t is time, θ is the angle value in the cylindrical coordinate system, z represents the longitudinal position of the winding, and the coordinates corresponding to a pancake at the bottom of the transformer winding are taken as the origin; since the size of each pancake is fixed, the radius r in the cylindrical coordinate system is a constant.

[0024] When current flows through the transformer winding, heat is generated. The temperature of the transformer winding is measured in real time by the built-in optical fiber temperature sensor of the winding. All temperature data are constructed according to the spatial relationship to construct a transformer winding temperature distribution cloud map (such as Figure 3 As shown); According to the 6°C rule of the transformer, the cloud map area with relatively high temperature must have a higher insulation risk; the relative temperature change gradient parameter is used as the fault parameter; Assuming that the temperature value of a point on the winding is T0, the temperature values ​​of the upper left, upper, upper right, right, lower left, lower right, lower left, lower left and left positions are selected as T1, T2, T3, T4, T5, T6, T7 and T8 respectively; Then the gradient coefficient in the time Δt range is defined as: η=(T1-T0) / Δt+(T2-T0) / Δt+(T3-T0) / Δt+(T4-T0) / Δt+(T5-T0) / Δt+(T6-T0) / Δt+(T7-T0) / Δt+(T8-T0) / Δt; The η value is initially set to 2, and a high temperature fault warning is issued when the real-time value is greater than the initial setting value.

[0025] The transformer operation load control method is based on the transformer holographic temperature field and the transformer real-time power value obtained after calculation by the analysis module. The specific implementation process is as follows:

[0026] (1) Divide each phase winding of the transformer into three sections according to the longitudinal parameter z. If the highest point of the winding corresponds to Zmax, the first section is [0, Zmax / 3], the second section is [Zmax / 3, 2Zmax / 3], and the third section is [2Zmax / 3, Zmax].

[0027] (2) Scan the holographic temperature field data of the three-phase winding of the transformer in sections to obtain the maximum temperature value corresponding to each section in the temperature body of each phase winding; taking the first phase winding of the transformer as an example, three maximum temperatures can be obtained, namely T1-1, T1-2, and T1-3;

[0028] (3) The position parameters of each phase winding corresponding to the maximum temperature value of each section are obtained through the formula T = f(t, θ, z), and a database of the relationship between the transformer winding current, voltage and temperature, angle and height is established; the position parameters of each phase winding corresponding to the maximum temperature values ​​T1-1, T1-2 and T1-3, θ1-1, θ1-2 and θ1-3Z1-1, Z1-2 and Z1-3 are obtained according to the formula T = f(t, θ, z); a database of the relationship between the transformer winding current and voltage and T1-1, T1-2 and T1-3, θ1-1, θ1-2 and θ1-3, Z1-1, Z1-2 and Z1-3 is established.

[0029] (4) Compare the size relationship between T1-1, T1-2 and T1-3 and the temperature threshold (this threshold can be set). When T1-1, T1-2 and T1-3 are greater than or equal to the temperature threshold, the system locks the voltage and current values ​​and determines the maximum load of the transformer.

[0030] (5) Based on the real-time measured temperature values ​​of T1-1, T1-2 and T1-3, the residual load that can be applied to the transformer is estimated.

[0031] The capacity margin of the operating transformer is dynamically calculated based on the conductor winding temperature data. The specific calculation method is as follows: obtain the highest temperature value from the Ti,j winding conductor temperature and record it as T(max), and the medium ambient temperature is Ten; store the T(max) value every 30 minutes and record it as: T(max)(time), and store Ten(time) and the corresponding transformer capacity Pow(time) at the same time; find out the value with a difference of less than 10% between Ten(time) and Ten in real time, take out the time mark, and then compare the real-time T(max) with the maximum value in T(max)(time), find out T(max)(time), and record the Pow(time) corresponding to the moment as the remaining amount value.

[0032] By operating a transformer with temperature measuring optical fibers on its windings for one year, the initial relationship between the transformer's maximum operating load and temperature can be obtained. In future operations, the transformer's load margin can be inferred through the holographic distribution of the transformer's winding temperature. The load margin can be used to accurately quantify the transformer's remaining capacity, providing data support for power system operation and maintenance personnel.

[0033] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An intelligent transformer system with fault self-diagnosis and power transmission self-regulation functions, characterized in that: It includes an intelligent analysis system, a data server and a collection terminal device, the output end of which is connected to the intelligent analysis service system through the data server; the intelligent analysis system includes a transformer winding line temperature data collection and storage module, a winding temperature data holographic presentation module and a transformer load capacity real-time calculation and display module; the transformer winding line temperature data collection and storage module is used for temperature collection and storage; the winding temperature data holographic presentation module is used for temperature holographic data presentation; the transformer load capacity real-time calculation and display module is used for real-time regulation of transformer load capacity, and real-time calculation and display of residual load margin; the collection terminal device is provided with a power supply interface, an optical fiber flange interface, a current collection port, a voltage collection port, an external temperature collection port and an internal temperature collection port, and a 220V AC power supply, the optical fiber flange interface is connected to the built-in temperature measuring optical fiber of the transformer, a current transformer is installed at the current acquisition port, a voltage transformer is installed at the voltage acquisition port, an outer surface temperature sensor is installed at the external temperature acquisition port, and an internal medium temperature sensor is installed at the internal temperature acquisition port; the built-in temperature measuring optical fiber includes an insulating paper tape, a temperature measuring component and a winding copper wire core, the outer side of the winding copper wire core is coated with an insulating paper tape, and a temperature measuring component is pre-installed at the inner center of the winding copper wire core, the temperature measuring component measures the temperature value of the contact surface between the winding copper wire core and the insulating paper tape, and the temperature measuring components are evenly spaced on the winding copper wire core to perform real-time monitoring of the full length range of the transformer winding; The temperature value of the transformer winding conductor is holographically described using cylindrical coordinates with time variables. The transformer winding is a cylindrical structure formed by spiral winding along the iron core. The line connecting the geometric centers of the planes where the windings of each layer are located is defined as the Z axis. The transformer winding temperature T can be expressed as follows using the cylindrical coordinate system: T=f(t,θ,r,z), where t is time, θ is the angle value in the cylindrical coordinate system; r is the winding radius; z represents the longitudinal position of the winding, and the bottom of the transformer winding is the center of the transformer winding. The corresponding coordinate is the origin, that is, z=0; because the size of each transformer winding is fixed, the radius r in the cylindrical coordinate system is a constant value, and the winding temperature T can be simplified to: T=f(t,θ,z); because the transformer winding has multiple phases, and each phase winding is composed of a high-voltage winding and a low-voltage winding, the winding temperature is further expressed as: Ti,j=f(t,θ,z), where i=1,2,3 represent the three-phase windings A, B, and C respectively, j=1 represents the low-voltage winding, and j=2 represents the high-voltage winding; The data measured by the optical fiber temperature sensor is the winding conductor temperature that can directly evaluate the thermal state of the transformer. The optical fiber temperature sensor built into the winding conductor can measure the transformer winding conductor temperature data set in real time, and all temperature data can be used to construct a transformer winding temperature distribution cloud map according to the temperature Ti,j function; The relative temperature change gradient parameter is used as the fault parameter; assuming that the temperature value of a point on the winding is T0, the temperature values ​​of the upper left, upper, upper right, right, lower left, lower right, lower and left positions are selected as T1, T2, T3, T4, T5, T6, T7 and T8 respectively; then the gradient coefficient in the time Δt range is defined as: η = (T1-T0) / Δt + (T2-T0) / Δt + (T3-T0) / Δt + (T4-T0) / Δt + (T5-T0) / Δt + (T6-T0) / Δt + (T7-T0) / Δt + (T8-T0) / Δt; the η value is a real-time value, and a high temperature fault warning is issued when the real-time value is greater than the initial set value.

2. The intelligent transformer system with fault self-diagnosis and power transmission self-regulation function according to claim 1 is characterized in that: The core of the transformer winding is equipped with a point-type or distributed optical fiber temperature sensor to directly measure the temperature of the winding conductor.

3. The intelligent transformer system with fault self-diagnosis and power transmission self-regulation function according to claim 1 is characterized in that: The transformer operation load control method is based on the transformer winding conductor holographic temperature data value and the transformer real-time power value obtained after calculation by the analysis module. The specific implementation process is as follows: (1) Divide each phase winding of the transformer into three sections according to the longitudinal parameter z. If the highest point of the winding corresponds to Zmax, the first section is [0, Zmax / 3], the second section is [Zmax / 3, 2Zmax / 3], and the third section is [2Zmax / 3, Zmax]; (2) Scan the holographic temperature field data of the three-phase winding of the transformer in sections to obtain the maximum temperature value corresponding to each section in the temperature volume of each phase winding; (3) The position parameters of each phase winding corresponding to the maximum temperature value of the three sections are obtained through the formula Ti,j=f(t,θ,z), and a database of the relationship between the transformer winding current, voltage, temperature, angle, and height is established; (4) Compare the obtained temperature value with the temperature threshold. When the obtained temperature value is greater than or equal to the temperature threshold, the system locks the voltage and current values ​​to determine the maximum load of the transformer; (5) Based on the temperature value measured in real time, the residual load that can be applied to the transformer is estimated.

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