A system for monitoring and controlling temperature of a dry-type transformer

Abstract

The present invention relates to a system (100) configured to monitor and control the temperature of a dry-type transformer (130) using a plurality of RTD sensors (104). The system (100) is configured to process real-time temperature data through a microprocessor- based scanner (106), which compares the sensed data against predefined thresholds and triggers alarms, fan activation, or transformer (130) shutdown if necessary. A human- machine interface (HMI) (108) is configured to display system status and allow user-defined configurations. A fault detection module (116) is configured to identify and disable faulty sensors to prevent false alarms. The system (100) further includes a communication interface (112) for remote monitoring, a battery module (114) for backup power, and a surge protection module (118) for voltage fluctuation protection. This invention enhances transformer (130) safety, improves operational reliability, and ensures proactive fault management in industrial applications.

Description

[0001] A SYSTEM FOR MONITORING AND CONTROLLING TEMPERATURE OF A DRY-TYPE TRANSFORMER FIELD

[0002] The present invention relates to the field of temperature monitoring and control systems for electrical transformers. More specifically, it relates to a system for monitoring and controlling the temperature of a dry-type transformer.

[0003] DEFINITION

[0004] As used in the present disclosure, the following terms are generally intended to have the meaning as set forth below, except to the extent that the context in which they are used indicates otherwise.

[0005] Pre-programmed algorithms: The term “pre-programmed algorithms” refers to the software -embedded logical instructions within the microprocessor-based scanner that analyze real-time temperature data from RTD sensors. These algorithms detect abnormal conditions, compare temperature values against predefined alarm and trip thresholds, and trigger corresponding control actions such as alarms, trips, or fan activation to ensure safe transformer operation.

[0006] ModBus protocol: The term “ModBus protocol” refers to a standardized communication protocol used for seamless data exchange between the temperature monitoring system and external control or monitoring systems. It enables remote access to transformer temperature data, alarm statuses, and control signals, allowing integration with centralized monitoring networks via the RS -485 interface.

[0007] RS-485 interface: The term “RS-485 interface” refers to a serial communication standard that facilitates long-distance, noise-resistant data transmission between the temperature scanner and remote monitoring systems. It ensures reliable communication by supporting multiple devices on a single network using the ModBus protocol for efficient data exchange.

[0008] PT100 platinum-based sensors: The term “PT100 platinum-based sensors” refers to a type of Resistance Temperature Detector (RTD) that has a nominal resistance of 100 ohms at 0°C. These sensors provide highly accurate and stable temperature measurements fortransformer windings and core, ensuring precise monitoring, early fault detection, and preventive temperature control.

[0009] These definitions are in addition to those expressed in the art.

[0010] BACKGROUND

[0011] The background information herein below relates to the present disclosure but is not necessarily prior art.

[0012] Generally, transformers are essential components in electrical power systems which is used to transfer electrical energy between circuits. The transformers are widely used in power generation, transmission, and distribution networks to step up or step down voltage levels. To ensure reliable and safe operation, temperature monitoring and control of transformers are crucial because overheating of the transformers can lead to insulation degradation, reduced lifespan, and even catastrophic failures.

[0013] Conventionally transformer temperature monitoring systems typically use temperature sensors such as Resistance Temperature Detectors (RTDs) or thermocouples to measure winding temperatures. These sensors measure the temperature and transmit the data to monitoring devices, typically analog or digital controllers. Some advanced versions allow manual threshold adjustments and basic remote monitoring via limited communication interfaces. Additionally, traditional systems may include cooling fan control to prevent overheating.

[0014] Despite these advancements, existing temperature monitoring systems have several limitations. Most conventional systems lack intelligent data processing and cannot differentiate between temporary overload conditions and critical overheating, leading to unnecessary shutdowns or delayed fault responses. Moreover, faulty RTD sensors can generate false alarms and trips, causing operational disruptions. Additionally, traditional systems have limited remote monitoring capabilities, often relying on outdated communication protocols, making real-time condition monitoring and predictive maintenance challenging.

[0015] There is, therefore, felt a need for a system for monitoring and controlling the temperature of a dry-type transformer that can alleviate the aforementioned drawbacks.OBJECTS

[0016] Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:

[0017] It is an object of the present disclosure to ameliorate one or more problems of the prior art or to at least provide a useful alternative.

[0018] An object of the present disclosure is to provide a system for monitoring and controlling temperature of a dry-type transformer.

[0019] Another object of the present disclosure is to provide a system that enables real-time temperature monitoring.

[0020] Still another object of the present disclosure is to provide a system that maintains reliable and accurate temperature control for windings and core.

[0021] Yet another object of the present disclosure is to provide a system that prevents overheating and enhances operational efficiency.

[0022] Another object of the present disclosure is to provide a system that predicts transformer faults. Still another object of the present disclosure is to provide a system that minimizes false alarms and unnecessary trips.

[0023] Yet another object of the present disclosure is to provide a system that integrates communication protocol for remote monitoring.

[0024] Still another object of the present disclosure is to provide a system that provides a humanmachine interface (HMI) for configuration and system control.

[0025] Yet another object of the present disclosure is to provide a system that offers robust surge protection to ensure reliable operation under varying electrical conditions.

[0026] Still another object of the present disclosure is to provide a system that supports automated cooling system activation for temperature regulation.

[0027] Yet another object of the present disclosure is to provide a method for monitoring and controlling the temperature of transformer coils.Other objects and advantages of the present disclosure will be more apparent from the following description when read in conjunction with the accompanying figures, which is not intended to limit the scope of the present disclosure.

[0028] SUMMARY

[0029] The present disclosure envisages a system for monitoring and controlling the temperature of a dry-type transformer. The system comprises a plurality of resistance temperature detector (RTD), a microprocessor-based scanner, a human-machine interface (HMI), an output control module, a communication interface, a battery module, a fault detection module, and a surge protection module.

[0030] The plurality of resistance temperature detector (RTD) sensors is configured to be mounted in low-voltage (LV) coils and the core of the transformer. The RTD sensors are configured to sense and transmit real-time temperature data.

[0031] In an embodiment, the RTD sensors are PT 100 platinum -based sensors with a nominal resistance of 100 ohms at 0°C.

[0032] The microprocessor-based scanner includes an alarm indication module, a trip indication module, a fault indication module, a battery status indication and a fan indication module. The microprocessor-based scanner is configured to be connected to each RTD sensor installed in the transformer. The microprocessor-based scanner is configured to:

[0033] o receive temperature input data from the RTD sensors;

[0034] o process the received temperature input data through pre-programmed algorithms to detect abnormal temperature conditions;

[0035] o compare the sensed temperature input data against user-defined alarm and trip thresholds; and

[0036] o generate corresponding control signals for the trip indication module, the alarm indication module, and the fan indication module when the temperature exceeds the thresholds.

[0037] The microprocessor-based scanner comprises:o two RTD sensors for each of the three low voltage coils of the transformer (RTD 1 & RTD4 for Coil 1, RTD2 & RTD5 for Coil 2, RTD3 & RTD6 for Coil 3);

[0038] o one RTD sensor for the transformer core (RTD7); and

[0039] o one spare RTD sensor (RTD8) for backup purposes in case of sensor failure.

[0040] The alarm indication module is configured to trigger an alarm signal when the temperature of both RTD sensors in a single coil exceeds a predefined alarm threshold and reset the alarm when the temperature drops below a differential threshold.

[0041] The trip indication module initiates a transformer shutdown if:

[0042] o both RTD sensors in a single coil exceed a first trip threshold for a predefined delay period; or

[0043] o both RTD sensors in a single coil exceed a second trip threshold, which is 40°C higher than the first trip threshold.

[0044] In an embodiment, the trip delay time is adjustable between 0-99 minutes, allowing users to mitigate false trips caused by transient temperature spikes and momentary temperature rise during temporary overloading

[0045] The human-machine interface (HMI) comprises a display monitor, pushbuttons, and LED indicators, wherein the human-machine interface (HMI) is configured to receive user-defined instructions and display the status and fault conditions. The HMI interface is further configured to allow users to configure operational parameters such as alarm and trip thresholds, trip delays, and sensor calibration.

[0046] In an embodiment, the HMI interface allows the user to define and adjust alarm and trip thresholds, differential values, and trip delay durations through a programmable menu interface.

[0047] The output control module is configured to transmit the control signals for alarm, trip, fault, fan, and remote indications to the microprocessor-based scanner.

[0048] The communication interface is configured to facilitate remote monitoring and data exchange via Modbus protocol over an RS-485 interface. In an embodiment, the communicationinterface is an RS-485 communication interface that enables real-time integration with the system and facilitates remote data access and diagnostics.

[0049] The battery module includes a rechargeable cell with an inbuilt charger, wherein the battery module ensures continuous operation and data logging during power outages. In an embodiment, the battery module operates at 3.6V with a 2.9Ah discharge capacity, which provides continuous operation for at least 16 hours when fully charged and activates autosleep mode to conserve battery life when idle for more than 3 minutes.

[0050] The fault detection module is configured to identify malfunctioning of the RTD sensors based on predefined criteria, disable faulty RTD sensors to prevent false alarms or trips, and provide visual alerts for troubleshooting. In an embodiment, the fault detection module is configured to disable any faulty RTD sensor if the temperature difference between paired RTD sensors in a coil exceeds 30°C, preventing false trips and alarms. In an embodiment, the fault detection module identifies sensor malfunctions by:

[0051] o detecting temperature readings beyond a predefined range (0°C-300°C);

[0052] o identifying a difference exceeding 30°C between paired RTD sensors in a coil; and o identifying open-circuit or short-circuit conditions in RTD connections.

[0053] The surge protection module comprises a Metal Oxide Varistor (MOV) and power line filters, wherein the power line filters are configured to protect the system against voltage fluctuations and surges.

[0054] In an embodiment, the system facilitates real-time condition monitoring, early fault detection, and preventive control actions to ensure effective temperature management of transformer windings and core.

[0055] In an embodiment, the system is configured to automatically reset the alarm and trip indications when the sensed temperature input data drops below a predefined differential value.

[0056] In an embodiment, the system further includes a temperature data logging module that is configured to store event history, including maximum attained temperatures and pre-faultconditions, which can be retrieved for analysis using the backup power supply during an outage.

[0057] In an embodiment, the system further includes a relay panel mounted on a transformer control cabinet and includes terminal connectors for external wiring of power, sensors, alarm, trip, and remote communication signals.

[0058] The present disclosure further envisages a method for monitoring and controlling the temperature of transformer coils. The method comprises:

[0059] • receiving real-time temperature data from a plurality of RTD sensors mounted in the low-voltage (LV) coils and core of the transformer;

[0060] • processing the received temperature data through a microprocessor-based scanner using pre-programmed algorithms to detect abnormal temperature conditions;

[0061] • comparing the sensed temperature data against user-defined alarm and trip thresholds;

[0062] • generating corresponding control signals for the alarm indication module, trip indication module, and fan indication module when the temperature exceeds predefined thresholds;

[0063] • transmitting the generated control signals via an output control module to activate alarm, trip, fault, fan, and remote indications;

[0064] • displaying real-time status, user inputs, and fault conditions on a human-machine interface (HMI) comprising a display monitor, pushbuttons, and LED indicators; • facilitating remote monitoring and data exchange through a communication interface using ModBus protocol over an RS-485 interface;

[0065] • ensuring continuous system operation and data logging during power failures via a battery module with a rechargeable cell;

[0066] • detecting and disabling faulty RTD sensors through a fault detection module to prevent false alarms and trips; and• protecting the system against voltage fluctuations and electrical surges using a surge protection module comprising a Metal Oxide Varistor (MOV) and power line filters.

[0067] BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING

[0068] A system for monitoring and controlling the temperature of a dry-type transformer, of the present disclosure, will now be described with the help of the accompanying drawing, in which:

[0069] Figure 1 illustrates a block diagram of the system in accordance with an embodiment of the present disclosure;

[0070] Figure 2 illustrates a front view of the device with a door in accordance with an embodiment of the present disclosure.

[0071] Figure 3 illustrates the inside view of the device without the door in accordance with an embodiment of the present disclosure ;

[0072] Figure 4 illustrates the left-side and right side view of the device in accordance with an embodiment of the present disclosure;

[0073] Figure 5 illustrates the top view of the device in accordance with an embodiment of the present disclosure;

[0074] Figure 6 illustrates the bottom view of the device in accordance with an embodiment of the present disclosure;

[0075] Figures 7A- 7E illustrate the flowchart of the system describing the trip and alarm logic in different temperature conditions, in accordance with an embodiment of the present disclosure; and

[0076] Figures 8A-8C illustrate a flowchart describing the method (800) for monitoring and controlling temperature of a dry-type transformer in accordance with an embodiment of the present disclosure.

[0077] LIST OF REFERENCE NUMERALS

[0078] 100 - System102 - Device

[0079] 104 - Resistance Temperature Detectors (RTD) sensors

[0080] RTD Sensors- RTD1, RTD2, RTD3, RTD4, RTD5, RTD6, RTD7 106 - Microprocessor-based scanner

[0081] 106a - Alarm indication module

[0082] 106b - Trip indication module

[0083] 106c - Fan indication module

[0084] 108 - Human -Machine Interface (HMI)

[0085] 108a - Display monitor

[0086] 108b - Pushbuttons

[0087] 108c - Light Emitting Diode (LED) indicators

[0088] 108c-l - Maximum Value Indication LED

[0089] 108c-2 - Set Value Indication LED

[0090] 108c-3 - Alarm Indication LED

[0091] 108c-4 - Fault Indication LED

[0092] 108c-5 - Trip Indication LED

[0093] 108c-6 - Fan Indication LED

[0094] 108c-7 - Battery Status LED

[0095] 110 - Output control module

[0096] 112 - Communication interface

[0097] 114 - Battery module114a- Rechargable cell

[0098] 116 - Fault detection module

[0099] 118 - Surge protection module

[0100] 118a - Metal Oxide Varistor (MOV)

[0101] 118b - Power line filters

[0102] 120 - Screw

[0103] 122 - Socket

[0104] 124 - Door

[0105] 126 - Metal body of device

[0106] 128 - PCB with Embeded logic circuit

[0107] 130 - Dry-Type Transformer

[0108] DETAILED DESCRIPTION

[0109] The present invention relates to the field of temperature monitoring and control systems for electrical transformers. More specifically, it relates to a system (100) for monitoring and controlling the temperature of a dry-type transformer (130).

[0110] Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details, are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.

[0111] The terminology used, in the present disclosure is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms "a,” "an," and "the" may beintended to include the plural forms as well, unless the context clearly suggests otherwise. The terms “including,” and “having,” are open ended transitional phrases and therefore specify the presence of stated features, elements and / or components, but do not forbid the presence or addition of one or more other features, elements, components, and / or groups thereof.

[0112] The terms first, second, third, etc., should not be construed to limit the scope of the present disclosure as the aforementioned terms may be only used to distinguish one element, component, region, layer, or section from another component, region, layer or section. Terms such as first, second, third, etc., when used herein do not imply a specific sequence or order unless clearly suggested by the present disclosure.

[0113] Generally, transformers are essential components in electrical power systems which is used to transfer electrical energy between circuits. The transformers are widely used in power generation, transmission, and distribution networks to step-up or step-down voltage levels. To ensure reliable and safe operation, temperature monitoring and control of transformers are crucial because overheating of the transformers can lead to insulation degradation, reduced lifespan, and even catastrophic failures.

[0114] Conventionally transformer temperature monitoring systems typically use temperature sensors such as Resistance Temperature Detectors (RTDs) or thermocouples to measure winding temperatures. These sensors measure the temperature and transmit the data to monitoring devices, typically analog or digital controllers. Some advanced versions allow manual threshold adjustments and basic remote monitoring via limited communication interfaces. Additionally, traditional systems may include cooling fan control to prevent overheating.

[0115] Despite these advancements, existing temperature monitoring systems have several limitations. Most conventional systems lack intelligent data processing and cannot differentiate between temporary overload conditions and critical overheating, leading to unnecessary shutdowns or delayed fault responses. Moreover, faulty RTD sensors can generate false alarms and trips, causing operational disruptions. Additionally, traditional systems have limited remote monitoring capabilities, often relying on outdated communication protocols, making real-time condition monitoring and predictive maintenance challenging.To address the issues of the existing systems and methods, the present disclosure envisages a system (hereinafter referred to as “system (100)”) for monitoring and controlling the temperature of a dry-type transformer and a method (hereinafter referred to as “method (800)”) for monitoring and controlling temperature of a dry-type transformer. The system (100) and the method (800) will now be described with reference to Figure 1 through Figure 8.

[0116] The transformer (130) is configured to be operatively connected to the system (100).

[0117] In an embodiment, the transformer (130) comprises a core and three low- voltage (LV) coils, designated as COIL1, COIL2, and COIL3.The system (100) comprises, a microprocessorbased scanner (106), a human-machine interface (HMI) (108), an output control module (110), a communication interface (112), a battery module (114), and a fault detection module (116).

[0118] In an embodiment, the system (100) is housed in a device (102) with dimensions of 270mm in length, 230mm in width, and 145mm in depth.

[0119] The plurality of resistance temperature detector (RTD) sensors (104) (hereinafter referred to as ‘sensors (104)’) are configured to be mounted in the low-voltage (LV) coils and core of the transformer (130). These sensors (104) are configured to collect real-time temperature data from different locations within the transformer (130) and transmit the temperature data to the microprocessor-based scanner (106) for data analysis.

[0120] In an embodiment, the RTD sensors (104) are PT 100 platinum -based sensors with a nominal resistance of 100 ohms at 0° C.

[0121] In an embodiment, the system (100) includes eight RTD sensors (104), wherein each coil has two sensors (Coil 1 - RTD1 & RTD4, Coil 2 - RTD2 & RTD5, Coil 3 - RTD3 & RTD6), one sensor is designated for the core (RTD7), and one sensor (RTD8) is kept as a backup.

[0122] The microprocessor-based scanner (106) is configured to monitor and control the temperature of the transformer (130) by analyzing real-time temperature data collected from the RTD sensors (104). The scanner (106) is configured to process the temperature data through preprogrammed algorithms to detect abnormal temperature conditions and execute control actions to prevent overheating and thermal damage.The microprocessor-based scanner (106) includes an alarm indication module (106a) configured to generate visual and remote alarm signals when the sensed temperature exceeds the predefined alarm threshold, a trip indication module (106b) which initiates the transformer (130) shutdown if the sensed temperature crosses the predefined trip threshold and a fan indication module (106c) activates the cooling fan system (100) when the sensed temperature reaches a defined limit, ensuring thermal regulation within the transformer (130). In an embodiment, the trip indication module (106b) operates based on a two-tier trip threshold mechanism:

[0123] o The first trip threshold triggers a shutdown if both RTD sensors (104) in a single coil exceed a predefined temperature for a set delay period, and o The second trip threshold, which is 40°C higher than the first, triggers an immediate shutdown to prevent severe overheating without waiting for the delay period.

[0124] In an embodiment, the first trip threshold is configurable between 100°C and 150°C, depending on the insulation class and operating conditions of the transformer (130). The second trip threshold is set at 40°C higher than the first trip threshold, making its range 140°C to 190°C. These values can be adjusted through the HMI (108) based on user-defined settings to optimize transformer (130) protection.

[0125] In an embodiment, the microprocessor-based scanner (106) executes a predefined delay before triggering atrip command to mitigate false tripping due to transient temperature spikes and momentary temperature rise during temporary overloading. The delay is user-adjustable within a range of 0-99 minutes.

[0126] The microprocessor-based scanner (106) is configured to receive temperature input data from the RTD sensors (104) mounted on the LV windings and core of the transformer (130). The scanner (106) processes the received temperature input data using pre-programmed algorithms that continuously evaluate sensor readings for temperature variations. The scanner (106) then compares the sensed temperature against the user-defined alarm and trip thresholds. When the temperature exceeds the preset thresholds, the scanner (106) generates corresponding control signals to activate the alarm indication module (106a), trip indicationmodule (106b), and fan indication module (106c), ensuring appropriate preventive actions are taken to maintain transformer (130) safety and performance.

[0127] In an embodiment, the alarm and trip thresholds are configurable within the range from 1°C to 300°C.

[0128] The microprocessor-based scanner (106) is further configured to reset alarm and trip indications automatically when the sensed temperature falls below a predefined differential value, which is programmable between 1°C to 60°C.

[0129] The microprocessor-based scanner (106) communicates with external monitoring and control systems via an RS-485 interface using the Modbus protocol, allowing remote data access and diagnostics.

[0130] The human-machine interface (HMI) (108) is positioned on the front side of the transformer (130) and comprises a display monitor (108a), push buttons (108b), and LED indicators (108c).

[0131] The human-machine interface (HMI) (108) is configured to allow users to define and adjust alarm and trip thresholds, differential values, and trip delay durations through a programmable menu interface. The display monitor (108a) is configured to present real-time temperature data, alarm and trip statuses, and historical temperature logs. The pushbuttons (108b) are configured to allow users to navigate through the interface, modify operational parameters, and confirm settings. The LED indicators (108c) are configured to provide visual alerts for active alarms, trips, sensor faults, fan operation, battery status, maximum value indication, and set value indication.

[0132] In an embodiment, the HMI (108) is configured with 8 pushbuttons (108b) and 7 LED indicators.

[0133] In an embodiment, the HMI (108) facilitates user interaction with the system (100) by providing real-time monitoring and system (100) diagnostics.

[0134] The output control module (110) is configured to transmit the control signals for alarm, trip, fault, fan, and remote indications to the microprocessor-based scanner (106). The output control module (110) serves as an interface between the scanner (106) and external control circuits, ensuring seamless operation and automated response to temperature variations.The module (110) is configured to process the generated control signals and direct them to corresponding output terminals, enabling alarm activation, transformer (130) shutdown, fan control, and remote monitoring functionalities.

[0135] In an embodiment, the system (100) includes 45 terminal connectors for structured input and output connections, facilitating organized wiring and reliable system (100) integration with external monitoring and control systems.

[0136] The communication interface (112) is configured to facilitate remote monitoring and data exchange using the Modbus protocol. The communication interface (112) enables real-time data transmission between the microprocessor-based scanner (106) and external monitoring systems, allowing users to remotely access transformer (130) temperature data and system (100) diagnostics.

[0137] In an embodiment, the communication interface (112) is an RS-485 interface.

[0138] In an embodiment, the communication interface (112) supports bidirectional communication, enabling both data retrieval and remote configuration of system (100) parameters.

[0139] The communication interface (112) is also configured with noise immunity features to enhance data integrity, even in electrically noisy environments. Additionally, the communication interface (112) supports multiple device connections, allowing integration with multiple transformers in a large-scale monitoring network.

[0140] The battery module (114) comprises a rechargeable Lithium-Ion cell (114a) configured to ensure continuous operation of the system (100) during power outages or auxiliary power failures. The battery module (114) serves as a backup power source, enabling the system (100) to function seamlessly in emergency conditions and allowing for uninterrupted monitoring and data logging.

[0141] In an embodiment, the battery module (114) operates at 3.6V with a 2.9Ah discharge capacity, ensuring at least 16 hours of continuous operation on a full charge.

[0142] In an embodiment, the battery module (114) is equipped with an auto-sleep mode, which is activated after 3 minutes of inactivity to conserve power and extend battery life.The batery module (114) is further integrated with an inbuilt charging circuit, which enables automatic recharging when external power is restored, ensuring the batery remains at optimal charge levels. Additionally, the system (100) provides an external socket for batery replacement, allowing users to easily swap out the batery without disrupting system (100) operation.

[0143] The fault detection module (116) is configured to identify faulty RTD sensors (104) and prevent false alarms or trips by continuously monitoring sensor performance and evaluating their output data against predefined criteria. The fault detection module (116) ensures reliable operation by isolating and disabling malfunctioning sensors (104), thereby preventing incorrect system (100) responses due to faulty readings.

[0144] The fault detection module (116) operates by analyzing temperature readings from all RTD sensors (104) and comparing them against expected values.

[0145] In an embodiment, if a temperature reading falls beyond the predefined operational range of 0°C-300°C, the system (100) flags the sensor as faulty.

[0146] Additionally, the fault detection module (116) detects inconsistencies between paired RTD sensors (104) within a transformer (130) coil. If the temperature difference between the two sensors (104) in a single coil exceeds 30°C, the system (100) identifies an anomaly and disables the affected sensors (104) to avoid false tripping or alarms.

[0147] Furthermore, the fault detection module (116) performs real-time diagnostics to identify open-circuit or short-circuit conditions in RTD connections. In case of an open circuit, where a sensor fails to provide a signal, or a short circuit, where a sensor gives abnormally high or low resistance readings, the system (100) immediately isolates the affected sensor and triggers an alert. The system (100) also provides visual and remote indications of sensor failures, allowing maintenance personnel to take corrective action promptly.

[0148] The surge protection module (118) is configured to safeguard the system (100) against electrical surges, voltage fluctuations, and transient spikes that may compromise the functionality of the microprocessor-based scanner (106) and other critical components. The surge protection module (118) includes a Metal Oxide Varistor (MOV) (118a) and power line filters (118b), both of which play a crucial role in maintaining system (100) stability and preventing damage caused by sudden voltage changes.In an embodiment, the Metal Oxide Varistor (MOV) (118a) is a voltage-dependent resistor that absorbs excess voltage when the supply voltage surpasses a predetermined threshold. When a voltage spike occurs, the MOV (118a) rapidly diverts the excess energy away from sensitive components, ensuring they remain within safe operating limits. This protection mechanism prevents insulation breakdown, component overheating, and potential failures caused by electrical transients.

[0149] In an embodiment, the power line filters (118b) eliminate electromagnetic interference (EMI) and radio-frequency interference (RFI), which can disrupt signal integrity and system (100) performance. These filters stabilize the power supply, ensuring that unwanted high-frequency noise does not interfere with data processing and communication functions within the system (100).

[0150] In an embodiment, the surge protection module (118) is calibrated to protect against voltage fluctuations within a predefined range of 85V to 440V AC / DC, ensuring that the system (100) operates reliably under varying power conditions.

[0151] In an embodiment, the system (100) further includes a temperature data logging module that is configured to store event history, including maximum attained temperatures and pre-fault conditions, which can be retrieved for analysis using the backup power supply during an outage.

[0152] In an embodiment, the system (100) further includes a relay panel mounted on a transformer (130) control cabinet and includes terminal connectors for external wiring of power, sensors, alarm, trip, and remote communication signals.

[0153] Figure 2 illustrates the front view of the transformer (130) with the door (124) in accordance with an embodiment of the present disclosure. The front view of the transformer (130) displays the human-machine interface (108). The Human-Machine Interface (HMI) (108) of the system (100) is configured to provide real-time monitoring, control, and diagnostics for the transformer. The HMI (108) comprises a display monitor (108a) for temperature readings, status indications, and system alerts; pushbuttons (108b) for user input, navigation, and parameter configuration; and LED indicators (108c) for visual alerts related to fault conditions, alarm status, trip activation, fan operation, and battery status. The HMI (108) facilitates user interaction through programmable menus, allowing the operator to definealarm and trip thresholds, adjust settings, and review historical data, ensuring efficient temperature management and system (100) protection.

[0154] Figure 3 illustrates the inside view of the device without the door (124) in accordance with an embodiment of the present disclosure. It depicts the terminal arrangement. The terminal arrangement comprises multiple connection points designed for interfacing with various system (100) components. It includes dedicated input terminals for multiple Resistance Temperature Detector (RTD) sensors (104), enabling real-time temperature monitoring of the transformer (130) windings and core. Furthermore, the terminal block incorporates designated output terminals for essential system (100) functions such as fault indication, fan control, alarm signalling, and trip activation. The following table 1 provides an overview of the terminal block applications and their respective functions.

[0155]

[0156] Figur

[0157] e 4

[0158] illustr ates the left side

[0159] and right side

[0160] views of the devic

[0161] e in accor

[0162] dance with

[0163] an embo

[0164]

[0165] dimen t of the present disclosure.

[0166] Figure 5 illustrates the top view of the device in accordance with an embodiment of the present disclosure.

[0167] Figure 6 illustrates the bottom view of the device in accordance with an embodiment of the present disclosure.

[0168] Referring to Figures 7A- 7E, the flowchart of the system (100) describes the trip and alarm logic in different temperature conditions, in accordance with an embodiment of the present disclosure.

[0169] Figure 7A illustrates the trip and alarm logic of the system (100) when all the RTD sensors are in healthy condition. The flowchart outlines the trip and alarm logic for transformer (130) protection using RTD sensor data. It monitors three transformer (130) coils, each with twosensors (104), along with a core temperature sensor and a spare sensor. If any RTD detects a temperature above 300°C, a fault indication is triggered. Additionally, if temperature difference between the two sensors (104) in a single coil exceed by 30°C, another fault alert is activated. For trip conditions, if the coil temperature surpasses the trip threshold for winding (11HDW) by 40°C, an immediate trip occurs. Otherwise, a counter starts, durig this delay temperature is continuously monitored and if it reaches a set delay and even if the the temperature value does not fall below the differential setpoint, the system (100) initiates a trip signal to prevent overheating damage.

[0170] The alarm logic activates if the detected temperatures exceed predefined thresholds (ATHDW for winding, ATHDC for the core). The alarm remains on until the temperature drops below the differential setpoint, ensuring stability against minor fluctuations. Once the temperature returns to safe levels, the alarm indication turns off. The system (100) continuously assesses temperature variations, ensuring real-time monitoring and protection of the transformer (130) through prompt alarms and trips.

[0171] Figure 7B illustrates the trip and alarm logic of the system (100) when only RTD Sensor RTD1 is faulty from coil (loop 1), in accordance with an embodiment of the present disclosure. When RTD sensor RTD1 from the coil is faulty, the system (100) identifies the fault by checking if RTD1 exceeds 300°C. If confirmed, the process moves into a separate fault-handling loop. Simultaneously, the system (100) verifies whether the other RTD sensor (RTD4) in the same coil is also faulty. If both RTD1 and RTD4 are faulty, the logic transitions into another fault loop for further handling.

[0172] If RTD4 is operational, the trip logic follows standard procedures by monitoring the remaining RTD sensors (104). If the temperature exceeds the trip threshold of winding (TTHDW) by 40°C, a trip command is initiated. Otherwise, a counter begins to track persistent overheating before triggering a trip after a set delay. The alarm logic activates if temperature values exceed predefined thresholds and deactivates once temperatures drop below the differential value, ensuring stable operation.

[0173] Figure 7C illustrates the trip and alarm logic of the system (100) when only RTD sensor RTD4 is faulty from the coil (loop 4), in accordance with an embodiment of the present disclosure. When RTD sensor RTD4 is detected as faulty, the system (100) transitions into a fault-handling loop (LOOP4). Despite this failure, the remaining RTD sensors (RTD1,RTD2, RTD3, RTD5, and RTD6) continue monitoring temperature conditions. If any of these sensors (104) detect a temperature exceeding the trip threshold (1THDW), the system (100) assesses whether the temperature rise surpasses the threshold by 40°C. If this condition is met, an immediate trip action is triggered. If not, a counter is initiated, incrementing with each temperature check. Once the counter reaches the set delay value, the system (100) executes the trip command to prevent overheating and potential damage.

[0174] Meanwhile, the alarm logic evaluates if the temperatures recorded by RTD1, RTD2, RTD3, RTD5, RTD6, and RTD7 exceed their respective alarm threshold values (ATHDW for winding temperature or ATHDC for core temperature). If any of these values surpass the threshold, the system (100) activates the alarm indication. The alarm remains active until the temperatures drop below their respective differential values (Diff), ensuring that the alarm is only triggered when necessary and is deactivated once conditions normalize. This process helps maintain continuous monitoring and prevents false alarms while ensuring safe transformer (130) operation.

[0175] Figure 7D illustrates the trip and alarm logic of the system (100) when both RTD1 and RTD4 are faulty from coil 1 (loop 3), in accordance with an embodiment of the present disclosure. When both RTD sensors RTD1 and RTD4 are detected as faulty, the system (100) enters a fault-handling loop (loop 3). Since these two sensors are non-functional, the system (100) relies on the remaining RTD sensors (RTD2, RTD3, RTD5, and RTD6) to monitor temperature conditions. If any of these sensors register temperatures exceeding the trip threshold (1THDW), the system (100) evaluates whether the temperature rise surpasses the threshold by 40°C. If this condition is met, an immediate trip action is executed. Otherwise, a counter mechanism is initiated, incrementing with each temperature check. When the counter reaches the predefined delay setting, the system (100) triggers a trip command to prevent overheating and potential transformer (130) failure.

[0176] In parallel, the alarm logic continues to monitor whether RTD2, RTD3, RTD5, RTD6, and RTD7 exceed their respective alarm threshold values (ATHDW for winding temperature or ATHDC for core temperature). If any sensor surpasses its set threshold, an alarm indication is activated. The alarm remains active until all temperature readings return to levels below their respective differential values (Diff). This logic ensures that the transformer (130) remains protected by providing timely alarms and trip actions even when two RTD sensors (104) are faulty.Figure 7E illustrates the trip and alarm logic of the system (100) when RTD1 or RTD4 are faulty from coil 1 (loop 2), in accordance with an embodiment of the present disclosure. When either RTD1 or RTD4 is faulty, the system (100) enters Loop 2 to manage the fault condition. The first step is checking whether the temperature readings from RTD2, RTD3, RTD5, or RTD6 exceed 300°C. If this condition is met, a fault indication is triggered, and the system (100) moves to a respective subroutine for further handling. If the temperature does not exceed this limit, the system (100) continues to monitor the remaining functional RTD sensors (104) for abnormal temperature conditions.

[0177] The system (100) then checks if RTD2, RTD3, RTD5, or RTD6 exceed the trip threshold (TTHDW). If they do, an additional verification determines whether the temperature rise surpasses TTHDW by 40°C. If this threshold is exceeded, an immediate trip action is executed. If not, the system (100) starts a counting mechanism, incrementing with each temperature check. If the count reaches a preset delay, a trip action is triggered. Meanwhile, the alarm logic continuously evaluates if any functional RTD sensors (104) exceed their respective alarm thresholds. If an over-temperature condition is detected, the alarm is activated and remains on until all sensors (104) return to safe levels. This dual-layered approach ensures fault detection, timely alarms, and system protection despite the failure of one RTD sensor.

[0178] Figures 8A-8B illustrate a flowchart describing the method (800) for monitoring and controlling the temperature of a dry-type transformer in accordance with an embodiment of the present disclosure. The order in which method (800) is described is not intended to be construed as a limitation, and any number of the described method steps may be combined in any order to implement method (800), or an alternative method. Furthermore, method (800) may be implemented by processing resource or computing device(s) through any suitable hardware, non-transitory machine -readable medium / instructions, or a combination thereof. The method 800 comprises the following steps:

[0179] At step 802, the method (800) includes, receiving real-time temperature data from a plurality of RTD sensors (104) mounted in the low-voltage (LV) coils and core of the transformer (130).At step 804, the method (800) includes, processing the received temperature data through a microprocessor-based scanner (106) using pre-programmed algorithms to detect abnormal temperature conditions.

[0180] At step 806, the method (800) includes, comparing the sensed temperature data against user-defined alarm and trip thresholds.

[0181] At step 808, the method (800) includes, generating corresponding control signals for the alarm indication module (106a), trip indication module (106b), and fan indication module (106c) when the temperature exceeds predefined thresholds. At step 810, the method (800) includes, transmitting the generated control signals via an output control module (110) to activate alarm, trip, fault, fan, and remote indications.

[0182] At step 812, the method (800) includes, displaying real-time status, user inputs, and fault conditions on a human-machine interface (HMI) (108) comprising a display monitor (108a), pushbuttons (108b), and LED indicators (108c). At step 814, the method (800) includes, facilitating remote monitoring and data exchange through a communication interface (112) using ModBus protocol over an RS-485 interface.

[0183] At step 816, the method (800) includes, ensuring continuous system (100) operation and data logging during power failures via a battery module (114) with a rechargeable cell.

[0184] At step 818, the method (800) includes, detecting and disabling faulty RTD sensors (104) through a fault detection module (116) to prevent false alarms and trips.

[0185] At step 820, the method (800) includes, protecting the system (100) against voltage fluctuations and electrical surges using a surge protection module (118) comprising a Metal Oxide Varistor (MOV) (118a) and power line filters (118b). In an operative configuration, the system (100) is configured to monitor and control the temperature of a dry-type transformer (130) by continuously acquiring, processing, andresponding to temperature variations detected in the transformer’s (130) low-voltage (LV) coils and core. It is configured to utilize a plurality of resistance temperature detector (RTD) sensors (104) that transmit real-time temperature data to a microprocessor-based scanner (106). The scanner (106) is configured to process temperature data using pre-programmed algorithms, compare the readings against user-defined alarm and trip thresholds, and generate control signals for the alarm indication module (106a), trip indication module (106b), and fan indication module (106c) to prevent overheating. The system (100) is further configured to incorporate an output control module (110) that transmits control signals for alarms, trips, and remote indications, as well as a communication interface (112) that facilitates remote monitoring and data exchange via Modbus protocol over an RS-485 interface.

[0186] To enhance reliability, the system (100) is configured to operate continuously during power outages using a rechargeable battery module (114) with an inbuilt charger, ensuring uninterrupted monitoring and data logging. It is also configured to integrate a fault detection module (116) that identifies and disables faulty RTD sensors (104) based on predefined criteria, preventing false alarms and trips. Additionally, the system (100) is configured to incorporate a surge protection module (118), comprising a Metal Oxide Varistor (MOV) (118a) and power line filters (118b), to protect against voltage fluctuations and electrical surges. The human-machine interface (HMI) (108) is configured to provide real-time status updates and allow users to configure operational parameters, including alarm and trip thresholds, differential values, and trip delays. With its integrated approach, the system (100) is configured to ensure accurate temperature monitoring, early fault detection, and preventive control actions, thereby enhancing transformer (130) performance and reliability.

[0187] Advantageously, the system (100) is configured to enhance transformer (130) safety and operational efficiency by integrating real-time temperature monitoring with intelligent control mechanisms. It is configured to utilize RTD sensors (104) for precise temperature measurement across the transformer’s (130) LV coils and core, enabling early detection of abnormal conditions. The microprocessor-based scanner (106) is configured to execute predefined algorithms that process temperature data, compare it against user-defined thresholds, and trigger alarms or shutdown actions to prevent transformer (130) failures. The system (100) is further configured to incorporate a user-configurable HMI (108) that allows operators to adjust temperature thresholds, trip delays, and differential values for flexible system management. Additionally, the fault detection module (116) is configured to preventfalse alarms by disabling malfunctioning RTD sensors (104), ensuring accurate monitoring. The communication interface (112) is configured to facilitate remote diagnostics via RS-485 and Modbus protocol, enabling seamless integration with SCADA systems. The system (100) is also configured to ensure uninterrupted operation through a battery module (114) that provides backup power during outages. Furthermore, it is configured to incorporate a surge protection module (118) to safeguard against electrical fluctuations. By offering a scalable and responsive temperature control solution, the system (100) is configured to reduce transformer (130) overheating risks, thereby improving equipment lifespan and reliability in industrial applications.

[0188] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope and spirit of the disclosure and appended claims. For example, due to the nature of software, functions described above can be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations. The foregoing description of the embodiments has been provided for purposes of illustration and is not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment but are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.

[0189] TECHNICAL ADVANCEMENTS

[0190] The present disclosure described hereinabove has several technical advantages including, but not limited to, the realization of a system for monitoring and controlling the temperature of a dry-type transformer, that:

[0191] • enables real-time temperature monitoring;

[0192] • maintains reliable and accurate temperature control for windings and core;prevents overheating and enhances operational efficiency;

[0193] predicts transformer faults ;

[0194] • minimizes false alarms and unnecessary trips;

[0195] • integrates communication protocol for remote monitoring;

[0196] • provides a human-machine interface (HMI) for configuration and system control;

[0197] • offers robust surge protection to ensure reliable operation under varying electrical conditions;

[0198] • supports automated cooling system activation for temperature regulation; and

[0199] • method for monitoring and controlling the temperature of transformer coils.

[0200] The aspect herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.

[0201] The foregoing description of the specific embodiments so fully reveals the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and / or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.

[0202] Any discussion of devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.

[0203] While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.

Claims

CLAIMS:

1. A system (100) for monitoring and controlling the temperature of a dry-type transformer (130), wherein said system (100) comprising:• a plurality of resistance temperature detector (RTD) sensors (104) configured to be mounted in low-voltage (LV) coils and core of said transformer (130), wherein said RTD sensors (104) sense and transmit real-time temperature data;• a microprocessor-based scanner (106) including an alarm indication module (106a), a trip indication module (106b), and a fan indication module (106c), said microprocessor-based scanner (106) configured to be connected to each RTD sensor (104) installed in said transformer (130), wherein said microprocessor-based scanner (106) is configured to:o receive temperature input data from said RTD sensors (104);o process the received temperature input data through pre-programmed algorithms to detect abnormal temperature conditions;o compare the sensed temperature input data against user-defined alarm and trip thresholds; ando generate corresponding control signals for the trip indication module (106b), the alarm indication module (106a), and the fan indication module when the temperature exceeds the thresholds;• a human-machine interface (HMI) (108) comprising a display monitor (108a), pushbuttons (108b), LED indicators (108c), configured to receive user-defined instructions and display the status and fault conditions;an output control module (110) configured to transmit the control signals for alarm, trip, fault, fan, and remote indications to said microprocessor-based scanner (106);• a communication interface (112) configured to facilitate remote monitoring and data exchange via Modbus protocol over an RS-485 interface;• a battery module (114) including a rechargeable cell with an inbuilt charger, wherein said battery module (114) ensures continuous operation and data logging during power outages;• a fault detection module (116) configured to identify malfunctioning of said RTD sensors (104) based on predefined criteria, disable faulty RTD sensors (104) to prevent false alarms or trips, and provide visual alerts for troubleshooting; and• a surge protection module (118) comprising a Metal Oxide Varistor (MOV) (118a) and power line filters (118b), wherein said power line filters (118b) configured to protect the system (100) against voltage fluctuations and surges; wherein said system (100) facilitates real-time condition monitoring, early fault detection, and preventive control actions to ensure effective temperature management of transformer (130) windings and core.

2. The system (100) as claimed in claim 1, wherein said system (100) is configured to automatically reset the alarm and trip indications when the sensed temperature input data drops below a predefined differential value.

3. The system (100) as claimed in claim 1, wherein said RTD sensors (104) are PT 100 platinum-based sensors with a nominal resistance of 100 ohms at 0°C.

4. The system (100) as claimed in claim 1, wherein said microprocessor-based scanner (106) comprises:• two RTD sensors for each of the three low voltage coils of the transformer (130) (RTD1 & RTD4 for Coil 1, RTD 2 & RTD5 for Coil 2, RTD 3 & RTD6 for Coil 3);• one RTD sensor for the transformer (130) core (RTD7); and• one spare RTD sensor (RTD8) for backup purposes in case of sensor failure.

5. The system (100) as claimed in claim 1, wherein said alarm indication module (106a) is configured to trigger an alarm signal when the temperature of both RTD sensors in a single coil exceeds a predefined alarm threshold and reset the alarm when the temperature drops below a differential threshold.

6. The system (100) as claimed in claim 1, wherein said trip indication module (106b) initiates a transformer (130) shutdown if:• both RTD sensors in a single coil exceed a first trip threshold for a predefined delay period; or• both RTD sensors in a single coil exceed a second trip threshold, which is 40°C higher than the first trip threshold.

7. The system (100) as claimed in claim 1, wherein the trip delay time is adjustable between 0-99 minutes, allows users to mitigate false trips caused by transient temperature spikes.

8. The system (100) as claimed in claim 1, wherein said battery module operates at 3.6V with a 2.9 Ah discharge capacity, which provides continuous operation for at least 16 hours when fully charged and activates auto-sleep mode to conserve battery life when idle for more than 3 minutes.

9. The system (100) as claimed in claim 1, wherein said HMI interface (108) allows the user to to define and adjust alarm and trip thresholds, differential values, and trip delay durations through a programmable menu interface.

10. The system (100) as claimed in claim 7, wherein said HMI interface (108) is configured to allow users to configure operational parameters such as alarm and trip thresholds, trip delays, and sensor calibration.

11. The system (100) as claimed in claim 1, wherein said fault detection module (116) is configured to disable any faulty RTD sensor (104) if the temperature difference between paired RTD sensors in a coil exceeds 30°C, preventing false trips and alarms.

12. The system (100) as claimed in claim 1, wherein said communication interface (112) is an RS-485 communication interface that enables real-time integration with said system and facilitates remote data access and diagnostics.

13. The system (100) as claimed in claim 1, wherein said fault detection module (116) identifies sensor malfunctions by:• detecting temperature readings beyond a predefined range (0°C-300°C);• identifying a difference exceeding 30°C between paired RTD sensors in a coil;and• identifying open-circuit or short-circuit conditions in RTD connections.

14. The system (100) as claimed in claim 1, further includes a temperature data logging module that is configured to store event history, including maximum attained temperatures and pre-fault conditions, which can be retrieved for analysis using the backup power supply during an outage.

15. The system (100) as claimed in claim 1, further includes a relay panel mounted on a transformer (130) control cabinet and includes terminal connectors for external wiring of power, sensors, alarm, trip, and remote communication signals.

16. A method (200) for monitoring and controlling the temperature of the transformer (130) coils, comprising:• receiving real-time temperature data from a plurality of RTD sensors (104) mounted in the low-voltage (LV) coils and core of the transformer (130); • processing the received temperature data through a microprocessor-based scanner (106) using pre-programmed algorithms to detect abnormal temperature conditions;• comparing the sensed temperature data against user-defined alarm and trip thresholds;generating corresponding control signals for the alarm indication module (106a), trip indication module (106b), and fan indication module (106c) when the temperature exceeds predefined thresholds;• transmitting the generated control signals via an output control module (110) to activate alarm, trip, fault, fan, and remote indications;• displaying real-time status, user inputs, and fault conditions on a humanmachine interface (HMI) (108) comprising a display monitor (108a), pushbuttons (108b), and LED indicators (108c);• facilitating remote monitoring and data exchange through a communication interface (112) using ModBus protocol over an RS-485 interface;• ensuring continuous system operation and data logging during power failures via a battery module (114) with a rechargeable cell;• detecting and disabling faulty RTD sensors (104) through a fault detection module (116) to prevent false alarms and trips; and• protecting the system (100) against voltage fluctuations and electrical surges using a surge protection module (118) comprising a Metal Oxide Varistor (MOV) (118a) and power line filters (118b).

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