BR202016024652U2 - PROVISION INTRODUCED ON THE APARTMENT OF INTERNAL Ducts TO A TRANSFORMER FOR MONITORING - Google Patents

Abstract

arrangement introduced in internal duct apparatus to a monitoring transformer new internal duct apparatus to an electrical monitoring power transformer used in general electrical systems, which allows, for example, the installation of optical sensors and other types They are intended to monitor the operation and status of the transformer to prevent failures.

Description

(54) Title: PROVISION INTRODUCED IN APPARATUS OF INTERNAL DUCTS TO A TRANSFORMER FOR MONITORING (51) Int. Cl .: H01F 27/28; H01F 38/00; G01R 15/24 (73) Holder (s): FOUNDATION CPQD - TELECOMMUNICATIONS RESEARCH AND DEVELOPMENT CENTER (72) Inventor (s): BRUNO NOGUEIRA AIRES; CLÁUDIO ANTONIO HORTENCIO; JOÃO GUILHERME DIAS DE AGUIAR; RODRIGO PERES; GUSTAVO HENRIQUE SBERZE RIBAS; EDUARDO FERREIRA DA COSTA (57) Abstract: ARRANGEMENT INTRODUCED IN AN INTERNAL DUCT APPARATUS TO A TRANSFORMER FOR MONITORING New apparatus of internal ducts to an electric power transformer for monitoring, used in electrical systems in general, which allows, for example, the installation of optical sensors and other types that have the purpose of monitoring the operation and status of the transformer, preventing the occurrence of failures.

1/14

PROVISION INTRODUCED IN INTERNAL DUCT APPARATUS TO A TRANSFORMER FOR MONITORING [001] This report deals with a detailed and illustrated description with figures of a new apparatus for internal ducts to an electrical power transformer for monitoring, used in electrical systems in general, the which allows, for example, the installation of optical sensors or other types that have the purpose of monitoring the operation and status of the transformer avoiding the occurrence of failures.

Field of the invention [002] The apparatus of internal ducts to a transformer for monitoring, object of the present invention, proposes the introduction of an apparatus composed of an infrastructure of internal ducts to an electric power transformer to enable access to internal points of interest of the transformer for, for example, the installation of optical sensors for the measurement and sensing of multiparameter of the transformer, and / or the installation of sensors of other types for various other functions. With this apparatus, the transformer is equipped with an infrastructure of ducts that are mechanically terminated in adapters, type of connection flange, arranged in the transformer housing to guide the sensors to the areas of interest for monitoring inside the transformer. The component ducts of the apparatus mechanically protect the sensors and guarantee the same dielectric conditions of the internal environment of the transformer.

Objective of the invention [003] The apparatus of internal ducts to a transformer for the installation of optical sensors, the object of the present invention, aims to provide the electric power transformer with an apparatus composed of an infrastructure of internal ducts with standardized flanges to enable the installation of sensors for measuring and sensing the transformer's multiparameters. In such a way that the ducts forward the sensor probes,

6/24

2/14 that carry the sensors, to the measurement points of interest inside the transformer, guaranteeing the physical integrity of the sensors throughout their useful life, allowing to install and remove the sensors from the transformer at any time, either when installing monitoring or during its operation and maintenance, still allowing the installation and removal of sensors with the transformer in operation, as well as the installation of sensor probes with various sensor technologies, such as optics and the installation of sensor probes for measurement of various parameters with any other type of sensor that may be needed, which may be from different manufacturers.

Problem to be solved [004] Power transformers are very important and strategic assets for the electrical sector due to substantial investments and their technical and functional importance for electrical systems, being one of the main elements that can affect the reliability of the electrical system as a whole, and that in many cases the occurrence of failures that can be catastrophic. Monitoring the operating conditions of the transformer can be very important to ensure the structural integrity of the system with a longer and more reliable service life.

[005] Various techniques are used to monitor the state of the transformer, such as: evaluation of the state by thermal analysis, evaluation of the state by means of vibration analysis, evaluation of the state by means of partial discharge analysis, evaluation of the state by analysis of dissolved gases (DGA) and state assessment through frequency response analysis, among others.

[006] Thermal stress is one of the main reasons that cause failures, since it is responsible for the deterioration of insulations and electrical components. The service life of the power transformers corresponds to the conditions of the electrical insulation of the materials, thus, the service life of the transformers is strongly affected by the winding temperatures.

7/24

3/14 [007] The traditional method for measuring the temperature of the winding of a transformer is to measure the temperature at the top of the transformer oil and estimate the temperature at the hot spots inside. Using conventional sensor technology, it is possible to measure the temperature inside the transformer only at the top, due to the dielectric limitations of the sensors, among other limitations. From the temperature measurement, internal and external, the temperature of the transformer winding and the location of the hot spots are obtained through the use of mathematical models. A non-invasive way to check the external temperature of the transformer's surface is thermography, which is the technique used to locate hot spots in electrical connections and identify hot spots.

[008] In view of the intrinsic characteristics of optical sensors, such as: immunity to electromagnetic interference (EMI), small size, high sensitivity, large bandwidth, among others, the use of sensors and optical fibers has been the focus of laboratory research for application in the measurement of various parameters of interest for monitoring in general, including in power transformers.

[009] With sensor technology and optical fibers it is possible to monitor the temperature in two different ways. One of them is the measurement of temperature distributed over the entire length of an optical fiber (DTS - Distributed Temperature System) wound along the winding of the transformer during its construction. Another possibility is Quasi-distributed measurement using a network of FBG (Fiber Bragg Grating) sensors, or a point sensor using the FBG sensor discreetly. Another possibility for spot temperature measurement is the use of optical interferometric sensors.

[010] Currently, transformer monitoring systems are mainly based on the measurement of parameters collected externally to them, or not directly at the point of interest. The solutions

8/24

4/14 commercial for direct measurement of the parameter of interest inside the transformer, are usually offered by the transformer manufacturer, their costs are very high and present a great difficulty for maintenance of the sensors, in case of failures.

[011] The use of optical sensors to monitor transformers has already been extensively studied, including in universities and research centers in Brazil and in the world, having presented very relevant results, however, adequate solutions have not been developed to ensure the maintenance of integrity structure of the optical fiber as a function of the mechanical stresses to which the fiber will be subjected during the life of the system inside the transformer. Another important aspect to consider is that the replacement of the optical sensors installed inside the transformer is practically impossible to be carried out in the field.

[012] This invention proposes a solution that overcomes these deficiencies, as it creates safe paths for access to the interior of the transformer in order to allow its sensing. In the proposed apparatus, several types of sensors can be installed and operated to measure various parameters, for example, the measurement of temperature at critical internal points, in real time.

State of the Art [013] There are some patent documents, national and international, that describe provisions and configurations arranged in transformers for their sensing, however none of these depositions has configuration and the functioning of the apparatus described in this patent. Among these documents, the following can be highlighted:

[014] The patent document, PI0205845-6, INDUCTIVE / OPTOELETRONIC ELECTRICAL CURRENT TRANSFORMER, where the present invention refers, to an inductive / optoelectronic electric current transformer based on hybrid technology using an electromagnetic induction coil with an optical source connected to you. The

9/24

5/14 light signals are encoded by directly triggering (modulating) the measurand on the said optical source. The optical signals thus produced are transmitted freely and / or by optical fiber to the ground potential. The sensor has great reliability, sensitivity, adequate dynamic range, is immune to electromagnetic interference, compact, light weight, can be extended for multipoint sensing, does not require in-situ energization and is connected to the ground potential maintaining insulation electrical. It allows to monitor in real time the measure of the average amplitude value and the instantaneous waveform of the electric current in transmission lines, as well as in devices such as insulators, bushings, lightning arresters and switches, subjected to an electrical potential (voltage) arbitrary, including 13.8 kV, 25.0 kV, 34.5 kV, 69 kV, 138 kV, 230 kV, 345 kV, 440 kV, 500 kV, 750 kV and 800 kV, it is robust, easy, cheap and safe to manufacture, install and use;

[015] Patent document PI 102012004343-2, OPTICAL ELECTRIC POTENTIAL TRANSFORMER, which describes a device that performs the measurement of alternating voltage values in a high voltage circuit, normally associated with a monitored power transmission line (1) high voltage electrical and the electro optical potential transformer, here called tpeo, is composed of an isolated measuring tower (3) connected to the connection point (2) and also of a measuring control unit, ucm (6) , installed inside a panel in the control and command room of the monitored installation; and the measuring tower (3) isolated has digital optical electric field sensors, which are connected and ucm by means of cables (7) of optical fibers without any metallic contact and based on the electric field values the ucm calculates in time real the value of the monitored and available voltage is information on a serial communication output or on a low power analog output;

[016] Patent document PI 102012006706-4, APPARATUS AND METHOD FOR MONITORING ELECTRICAL CONTACT, refers to optical monitoring systems for disconnect switches that, according to their

10/24

6/14 general characteristics, its basic principle is to provide: support the operating conditions (nominal voltage, vibration, temperature, oxidation, humidity, etc.); remote indication of closing and effective opening of the disconnect switch (CS); ensuring proper isolation between the potential sensor part of the CS and the monitoring part of the potential ground; cost compatible with that of the CS; ability to be installed on old css and possibility to be manufactured together with new css; non-interference in operation or damage to the electrical insulation of the CS; immunity to electromagnetic interference and electrical or mechanical noise as well as vibrations of any kind;

[017] Patent document BR 10 2012 032602 7, THERMAL TRANSFORMER MONITORING SYSTEM BY BRAGG OPTICAL SENSORS, refers to a temperature monitoring system in windings of power transformer coils. A channel-type device is proposed to accommodate and protect the FBG sensors and an elliptical shaped duct to protect the assembly that is fixed vertically to the coil. The optical fibers are routed to the outside through a cover on the top and are terminated in a box fixed on the outside of the transformer. The order describes the construction of the proposed solution and it is clear that it is not possible to install and remove the sensors without physical intervention inside the transformer. [018] Patent document CN202631524U, ONLINE MONITORING DEVICE OF MICRO MOISTURE IN OPERATION TRANSFORMER OIL, describes a system for real-time monitoring of moisture in the transformer oil using a sensor that is installed in the oil circulation pipe; and [019] Patent document KR20040020345 (A), APPARATUS FOR SIMULTANEOUSLY MEASURING CURRENT AND VOLTAGE BY USING OPTICAL FIBER AND METHOD FOR THE SAME, which describes a device for simultaneously measuring a current and a voltage using a fiber

11/24

7/14 optics and a method for it are provided, and are easily installed in a conventional electrical transformer or a conventional optical crystal sensor. An apparatus for simultaneously measuring a current and a voltage using an optical fiber includes a laser (1), a first polarization plate (2), a polarization modulator (3), a sensor head (4), a second polarization plate (5), an optical detector (6), a lock-in amplifier (8) and a conversion block. The laser (1) generates a laser beam and the first polarization plate (2) deflects the laser beam generated by the laser (1) at a predetermined angle. The polarization modulator (3) generates an electrical signal for the reference voltage and periodically modulates linear polarized light to circular polarized light. The sensor head (4) induces changes from linear polarized light to current and circular polarized light to voltage. The second polarization plate (5) causes the light from the sensor head (4) to be polarized at a predetermined exit angle. The optical detector (6) changes the light of the second output polarization plate (5) in an electrical signal. The lock-in amplifier (8) measures the amount of changes in the circular light when receiving the electrical polarization signal from the modulator (3) and the optical detector (6). And, the block converts the number of polarization changes of the lock-in amplifier (8) to the current and voltage values.

[020] Some scientific articles that represent the State of the Art, studies and results carried out in the area, as bibliographic references, can also be cited below;

[021] WANG, M .; VANDERMAAR, A. J .; SRIVASTAVA, K. D. Review of condition assessment of power transformers in service. IEEE Electrical Insulation Magazine, v. 18, n. 6, p. 12-25, 2002;

[022] Abu-Elanien, A. E. B., & Salama, M. M. A. (2010). Asset management techniques for transformers. Electric Power Systems Research, 80 (4), 456-464; [023] Lee, M., Abdullah, H. A., Jofriet, J. C., & Patel, D. (2010). Temperature distribution in foil winding for ventilated dry-type power transformers. Electric Power Systems Research, 80 (9), 1065-1073;

12/24

8/14 [024] DE RYBEL, Tom et al. Apparatus for online power transformer winding monitoring using bushing tap injection. IEEE Transactions on Power Delivery, v. 24, n. 3, p. 996-1003, 2009;

[025] Mak, T., Westerwaal, R. J., Slaman, M., Schreuders, H., Van Vugt, A. W., Victoria, M., Dam, B. (2014). Optical fiber sensor for the continuous monitoring of hydrogen in oil. Sensors and Actuators, B: Chemical, 190, 982-989;

[026] LEE, Byoungho. Review of the present status of optical fiber sensors. Opticalfibertechnology, v. 9, n. 2, p. 57-79, 2003;

[027] Lobo Ribeiro, A. B., Eira, N. F., Sousa, J. M., Guerreiro, P. T., & Salcedo, J.

R. (2008). Multipoint fiber-optic hot-spot sensing network integrated into high power transformer for continuous monitoring. IEEE SensorsJournal, 8 (7), 12641267;

[028] DE FARIA, Ivan Paulo; MARTINEZ, Manuel Luis Barreira; DA COSTA PARENTONI, Marcel Fernando. Comparison of volumetric thermal mapping systems applied to power transformers;

[029] Yu, B., Kim, D.W., Deng, J., Xiao, H., & Wang, A. (2003). Fiber FabryPerot sensors for detection of partial discharges in power transformers.Appl Opt, 42 (16), 3241-3250.

[030] Kim, M., Lee, J., Koo, J., & Song, M. (2008) .A study on internal temperature monitoring system for power transformer using optical Fiber Bragg Grating sensors. Electrical Insulating Materials, 163-166;

[031] Chen, W. G., Liu, J., Wang, Y. Y., Liang, L. M., Zhao, J. B., & Yue, Y. F. (2008). The measuring method for internal temperature of power transformer based on FBG sensors. 2008 International Conference on High Voltage Engineering and Application, ICHVE 2008, 672-676;

[032] Saravolac, M. P. (1994). The use of optic fibers for temperature monitoring in power transformers. The Institution of Electrical Engineers, 1-3. [033] PICANÇO, Alessandra F .; MARTINEZ, Manuel LB; ROSA, Paulo C. Bragg system for temperature monitoring in distribution transformers.Electric Power Systems Research, v. 80, n. 1, p. 77-83, 2010.

13/24

9/14 [034] FARIA, IVAN P., PARENTONI, MARCEL F. C., MARTINEZ, M. L. B. (2012). Thermal monitoring of transformers using optical fiber sensors: technologies and applications. i, 4968-4974. Retrieved from;

[035] Deng, J., Xiao, H., Huo, W., Luo, M., May, R., Wang, A., & Liu, Y. (2001) .Optical fiber sensor-based detection of partial discharges in power transformers. Optics & Laser Technology, 33 (5), 305-311;

[036] MA, Guo-ming et al. High sensitive and reliable fiber Bragg grating hydrogen sensor for fault detection of power transformer. Sensors and Actuators B: Chemical, v. 169, p. 195-198, 2012;

[037] BETTA, Giovanni; PIETROSANTO, Antonio; SCAGLIONE, Antonio.An enhanced fiber optic temperature sensor system for power transformer monitoring. In: Instrumentation and Measurement Technology Conference, 2000. IMTC 2000. Proceedings of the 17th IEEE.IEEE, 2000. p. 153-158; [038] MORAIS, Diego Roberto et al. Intelligent tool for the detection of incipient faults in transformers based on the analysis of gases dissolved in the insulating oil. 2004;

[039] SILVA, Juliano Ricardo da et al. Modeling for thermal monitoring of transformers in operation and evaluation of aging according to the loading profile. 2005;

[040] MA, Guo-ming et al. High sensitive and reliable fiber Bragg grating hydrogen sensor for fault detection of power transformer. Sensors and Actuators B: Chemical, v. 169, p. 195-198, 2012;

[041] Dai, J., Yang, M., Yu, X., & Lu, H. (2013) .Optical hydrogen sensor based on etched fiber Bragg grating sputtered with Pd / Ag composite film. Optical Fiber Technology, 19 (1), 26-30; and [042] Wang, X., Li, B., Roman, H. T., Russo, O. L., Chin, K., & Farmer, K. R. (2006). Acousto-optical PD detection for transformers. IEEE Transactions on Power Delivery, 21 (3), 1068-1073.

Description of the figures

14/24

10/14 [043] Below, reference is made to the Figures accompanying this descriptive report, for better understanding and illustration, where it can be seen:

[044] Figure 1 shows a schematic in perspective of the arrangement introduced in Apparatus of internal ducts to a transformer for installation of optical sensors, object of the present patent, highlighting all its configuration details.

[045] Figure 2 shows a schematic in front view of the arrangement introduced in Apparatus of internal ducts to a transformer for installation of optical sensors or other types, object of this patent, highlighting its configuration details of the Apparatus (A) and the termination panel (B) of the internal ducts with their standardized flanges.

Description of the invention [046] The following describes a preferential, non-restrictive form of realization of the present apparatus, object of this patent, where the configuration and application can vary in the appropriate form for each desired model; describing one of the constructive possibilities that lead to realizing the described object and the way it works.

[047] The apparatus of internal ducts to a transformer for installation of monitoring sensors, object of the present patent, is an infrastructure of internal ducts (1) to an electric transformer of power to access points of interest, which allows the installation of monitoring and measurement sensors at their ends (3) for the measurement and sensing of multiparameters. The ducts (1) are filled with substances, or solutions, or insulating means of the transformer core and are terminated on a standardized flange (2) arranged in a termination panel (4) strategically located in the transformer tank housing to allow for the installation and removal of sensors at any time, either when installing monitoring systems or during their operation and maintenance, with the transformer in operation or not. The ducts (1) route the sensor probes to the points of interest of

15/24

11/14 measurement (3) inside the transformer and guarantee physical integrity of the sensor probes throughout their useful life. The apparatus allows the installation of probes of various optical sensor technologies for the measurement of various parameters and may, with standardized flanges, allow the installation of sensor probes from different manufacturers, where the choice of the type of sensor probe is defined according to the parameter that you want to measure.

Preferred form of realization and operation of the invention [048] The Apparatus of internal ducts to a transformer for installation of optical sensors, object of the present patent, is formed by an infrastructure of ducts (1) installed internally to an electric power transformer to allow the installation of optical sensors (2) for the measurement and sensing of multiparameters. The ducts are finished in flanges arranged in a termination panel (4) strategically located in the transformer tank housing to allow installation and removal of the sensors at any time, either when installing monitoring systems or during their operation and maintenance , and with the transformer still in operation. The ducts route the sensor probes to the measurement points of interest inside the transformer (3) and guarantee the physical integrity of the sensor probes throughout their useful life. The apparatus allows the installation of probes of various optical sensor technologies for the measurement of various parameters and can, with standardized flanges (4), allow the installation of sensor probes from different manufacturers.

[0497] The ducts must be constructed of material with dielectric characteristics suitable for the internal environment of the transformer, such as PTFE (Polytetrafluoroethylene), that is, that is compatible in relation to electrical and chemical aspects and that does not degrade during its useful life . When installed, the interiors of the ducts must be completely filled with the insulating oil (solution) from the transformer core, without air bubbles and / or other particles that may provide partial discharges. To ensure

16/24

12/14 complete filling of the interior of the duct some possibilities can be implemented, such as: bleeding the duct by the suction method to ensure complete filling with insulating oil, or using perforated ducts, as long as the solution guarantees perfect conditions medium dielectrics.

[050] The basic functions of the ducts (1) are: to provide the routing of the sensor probes to the points of interest of measurement and to guarantee the physical integrity of the probes during the operation of the system. In this context, the ducts must be adequately fixed to the flanges (2) of the access panel (4) of the probes and guide them along their lengths routed inside the transformer to the termination points (3). [051] The flanges (2), on the inside of the transformer, must guarantee the perfect connection with the ducts throughout the life of the system. The internal part of the flange must be provided with a diaphragm, preferably made of silicone rubber, to seal the insulating oil during the process of installing or removing the sensor probes. The external part of the flange must allow the connection of the sensor probe terminations and guarantee a perfect seal during the operation, and if not used, it must have a sealing plug that can be removed when the installation of a sensor probe.

[052] The sensor probe must be built in order to meet the specific needs of the measurement point of each duct, that is, it must be built according to the distance from the flange to the measurement point. The optical fiber of the sensor probe must be coated / protected by a polymer resistant to the operating environment, compatible with electrical and chemical aspects and that does not degrade during its useful life. The fiber coating must be carried out, preferably using PTFE, with dimensions that guarantee the necessary strength and flexibility for the process of insertion and removal of the ducts.

17/24

13/14 [053] The sensor probes can be built using various sensor technologies, the choice of type being defined according to the parameter to be measured. Among the sensor technologies that can be used, the FBG (Fiber Bragg Grating) technology and the interformetric optical sensor technology can be highlighted. Using FBG technology, sensor probes can be built with more than one sensor, which can be located in pre-established positions for measurement at different points. The length of the sensor probes is defined according to the distances from the measurement points in relation to the input flanges in the transformer. [054] Although the use of the apparatus of internal ducts to the power transformer using optical sensors has been exemplified, the apparatus can be used for the application of other types of sensors (non-optical, hybrid) and other purposes, for example , the collection of material sample (insulating solution) at points of interest accessible through the apparatus. Advantages [055] In this way, the Arrangement introduced in Apparatus of internal ducts to a transformer for installation of optical sensors, object of the present patent, as described above, presents a new configuration and operation that configure it with great advantages in relation to the apparatuses and devices currently used and found on the market for the same function. Among these advantages we can mention: the fact that the ducts send the sensor probes to the measurement points of interest inside the transformer resulting in a real measurement; the fact that the pipeline infrastructure guarantees the physical integrity of the sensors throughout their useful life; the fact that the pipeline infrastructure allows the installation and removal of the transformer sensors at any time, either when installing monitoring systems or during their operation and maintenance; the fact that the pipeline infrastructure allows the installation and removal of sensors with the transformer in operation; the fact that pipeline infrastructure allows the installation of sensor probes with various optical sensor technologies; O

18/24

14/14 the fact that the pipeline infrastructure allows the installation of sensor probes to measure various parameters and may use more than one sensor per probe; and, the fact that the pipeline infrastructure, with standardized flanges, allows the installation of sensor probes from different manufacturers, reducing overall costs.

[056] Thus, due to the configuration and operation characteristics, described above, it can be clearly noted that the PROVISION INTRODUCED IN AN INTERNAL DUCT APPARATUS TO A TRANSFORMER FOR MONITORING, it is a new apparatus for the State of the Art which it covers conditions of innovation, inventive act and unprecedented industrialization, which merit the Utility Model Patent Privilege.

19/24

1/1

Claims (1)

CLAIM 1 - ARRANGEMENT INTRODUCED IN APPARATUS OF INTERNAL DUCTS TO A TRANSFORMER FOR MONITORING, Apparatus of internal ducts to a transformer for access to internal points of interest for monitoring such as data collection and sensing, which allows the installation of sensor probes, characterized by being formed by an infrastructure of internal ducts to the transformer (1) for access to points of interest for installing sensors at its ends; said ducts being completely filled with insulating medium from the transformer core, and being installed internally to the electric power transformer with variable flange distances to the monitoring point for each desired point; said ducts are finished in flanges (2), preferably standard flanges, in connection with the ducts (1) containing a diaphragm or a sealing plug; said flanges (2) being arranged in a termination panel (4) strategically located in the transformer tank housing for the installation and removal of monitoring devices at any time; said pipelines route the monitoring sensor probes to the points of interest inside the transformer (3) and guarantee their physical integrity throughout their useful life; said sensor monitoring probes can be built with various sensor technologies for the measurement of various parameters, the choice of type being defined according to the parameter to be measured. 20/24 1/1