Intelligent dry-running monitoring system for dry-running protection in deep well motors

Abstract

A dry-running monitoring system (10), comprising: at least two temperature sensors (T-sensors) (3), a housing tube (5) and an intelligent electronic subsystem (8), which in turn consists of a Wheatstone bridge circuit (8a), a low-noise front end (8b), a microcontroller (8c), a solenoid circuit (8d), a push-pull solenoid (6) and a power supply unit (8e) wherein the two temperature sensors (3) are used to detect low water levels based on their contact / non-contact status with the water; at least two T-sensors are connected to a Wheatstone bridge circuit configuration (8a) within the intelligent electronic system (8), wherein the differential output signal of the Wheatstone circuit is passed to a low-noise differential amplifier front end, followed by an A / D conversion (8b), wherein the A / D signals are then passed to a microcontroller (8c) with wireless IoT capabilities, wherein the microcontroller, through its embedded program, continuously checks for threshold violations in the detected differential signals and detects a low water level or equivalent dry-run condition within the well, wherein, upon detection of a low water level condition, the microcontroller activates a magnetic circuit (8d) via a power MOSFET (8d1), which in turn mechanically actuates and controls the push-pull magnet; and, A mechanical actuation of the magnet switches off the wall-mounted power supply for the motors (9) and prevents the motors from running dry, while the wireless microcontroller (8c) simultaneously sends warning messages to the user or farm owner via its IoT interface.

Description

TECHNICAL FIELD

[0001] The present invention relates to the field of "Intelligent system for monitoring submersible motors" and related techniques. More specifically, the present invention relates to an intelligent system for preventing dry-running situations in submersible motors by utilizing sensing, electronic processing, and actuation techniques in combination with IoT for remote user feedback and control. BACKGROUND

[0002] Deep well motors (submersible motors) are widely used in farms for irrigation purposes. In deep well motors, "dry running" refers to a situation where the well water level becomes extremely low or empty due to constant water drainage, yet the motor continues to run without much water to pump. In this dry running situation, if a motor continues to run, it will eventually fail due to internal motor malfunction, resulting in financial and production losses for the farm owners. This is a difficult situation that often occurs in irrigation farms where submersible motors run continuously unmanned for extended periods. Therefore, there is a need for autonomous monitoring of dry running situations in submersible motors to prevent frequent failures.Furthermore, there is also a need for remote user feedback and control so that farm owners can proactively respond to this situation. This invention provides a robust solution to this dry-running problem using intelligent sensor and electronic automation techniques combined with IoT. OBJECT OF THE INVENTION

[0003] The main objective of the present invention is to provide an intelligent electronic system combined with IOT for monitoring dry running situations in deep well motors to prevent frequent motor failures.

[0004] Another object of the present invention is to implement intelligent monitoring using cost-effective techniques so that it is economically viable for farm owners.

[0005] Another object of the present invention is to enable easy installation, maintenance, and repair of the intelligent monitoring itself since the submersible motors are installed at the bottom of deep wells that may be 100 feet or more deep.

[0006] Another object of the present invention is to provide the possibility of retrofitting the intelligent monitoring method so that its on-site installation becomes simple, quick and problem-free without disturbing the existing installation.

[0007] Another objective of the present invention is to provide a parallel, independent operation of intelligent functions so that a failure of the intelligent monitoring system on-site does not affect the motor function in any way. The user can continue to run the motors until the intelligent monitoring component is repaired.

[0008] Another object of the present invention is to give the user full manual control over enabling / disabling intelligent features during field use.

[0009] Another objective of the present invention is to enable the user to remotely control and provide feedback on the entire system function conveniently from their mobile device. This improves the user experience and increases confidence in the system's real-time functionality.

[0010] Another object of the present invention is to enable universal intelligent monitoring of dry running situations regardless of the motor specifications (e.g. motor power / watt, voltage and power consumption range, etc.).

[0011] These and other objects and advantages of the present invention will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings. SUMMARY

[0012] The various embodiments of the present invention disclose an intelligent electronic system in combination with IOT for monitoring dry-running situations in deep well motors to prevent frequent motor failures.

[0013] The smart electronics system of the present invention comprises sensors and associated electronics for detecting low water levels in deep-well motors. The water level sensing method of the present invention is unique and relies on the use of temperature sensors (T-sensors) submerged at the bottom of the well. They sense the water level by utilizing the temperature difference when they are in contact with / out of contact with the water. Dual T-sensors connected in a Wheatstone bridge configuration are used for differential sensing. The output signal of the dual T-sensors is passed to an embedded smart electronics processing subsystem. This subsystem includes a low-noise front end, a microcontroller, a power supply circuit, and a solenoid circuit.The low-noise front-end performs the functions of amplification, filtering, and A / D conversion of the acquired signals. The output of the A / D converter is passed to a microcontroller, which executes an embedded program to detect the contact / non-contact situation of the T-sensors. Upon detecting the non-contact situation in the T-sensors, the microcontroller activates a magnetic circuit to control the push-pull magnet. The push-pull magnet is mechanically actuated to turn off the wall-mounted power supply of the deep well motor. At the same time, the microcontroller sends an alert to the farm owner via its wireless interface regarding the motor's operating status and further action to be taken.The entire intelligent electronic system, with the exception of the T-sensors, is integrated into a single electronic board, enclosed in a protected housing, and conveniently located as a separate unit near the wall-mounted power switch for the motors. However, the dual T-sensors are submerged at a predetermined height near the bottom of the deep well, indicating a low water level in the deep well.

[0014] These and other aspects of the embodiments described herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that while the following descriptions indicate preferred embodiments and numerous specific details thereof, they are intended to be illustrative and not limiting. Many changes and modifications may be made within the scope of the embodiments described herein without departing from the spirit thereof, and the embodiments described herein are intended to include all such modifications. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The other objects, features and advantages will become apparent to those skilled in the art from the following description of the preferred embodiment and the accompanying drawings in which: Fig. shows the use case application of the intelligent dry-running monitoring system in deep wells in conjunction with submersible motors. Fig. shows the block diagram of the intelligent dry-running monitoring system. Fig. shows the Wheatstone bridge circuit configuration for differential sensing based on a dual T-sensor. Fig. shows the magnetic circuit in connection with the push-pull magnet modeled as an inductor coil.

[0016] Although specific features of the present invention are shown in some drawings and not in others, this is done for convenience only, as each feature may be combined with any or all of the other features of the present invention. DETAILED DESCRIPTION

[0017] The various embodiments and other developments and features are presented with reference to the non-limiting details in the following detailed description. The illustration of processing techniques of known components is omitted so as not to unnecessarily obscure the embodiments contained herein. The examples used herein are intended to facilitate understanding of the ways in which the embodiments contained herein may be implemented and to enable those skilled in the art to implement the embodiments contained herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments contained herein.

[0018] The various embodiments of the present invention disclose an intelligent dry-run monitoring system for preventing frequent motor failures in deep-well motors through water level measurement. The intelligent dry-run monitoring system (10) consists of two temperature sensors (T-sensors), a casing tube, and an intelligent electronics subsystem, which in turn consists of a Wheatstone bridge circuit, a low-noise front-end circuit, a microcontroller, a solenoid circuit, and a push-pull solenoid. The two temperature sensors (3) are used to detect low water levels based on their contact / non-contact situation with the water. The dual T-sensors are connected to a Wheatstone bridge circuit (8a) within the intelligent electronics system (8).The differential output signal of the Wheatstone circuit is passed to a low-noise differential amplifier front-end, followed by A / D conversion (8b). The A / D signals are then passed to a microcontroller (8c) with wireless capabilities. The microcontroller, via its embedded program, checks whether the detected differential signals exceed a threshold to detect low water levels. The microcontroller is connected to a magnetic circuit (8d) that activates / deactivates the push-pull magnet using a power MOSFET (8d1), which in turn mechanically actuates and controls the ON / OFF state of the wall-mounted power supply switch for the motors (9). At the same time, the microcontroller (8c) uses its wireless interface to generate alerts to the user.

[0019] Fig. shows the application scenario of the intelligent dry-run monitoring system according to an embodiment of the present invention. Deep wells (1) are equipped with submersible motors (2) placed at the bottom of the well to pump water through the outlet pipe to the farms for irrigation purposes. The submersible motors are powered by a wall-mounted electrical switch (9) via insulated power supply cables (7). Near the bottom of the well, a user-friendly threshold is set as the low-level threshold (11), which must be detected. When the well water falls below this low-level threshold (11), the submersible motor must be switched off to prevent dry-running of the motors and prevent motor failures. Two temperature sensors (3) ( Fig. ). One temperature sensor Ts1 is placed above the threshold, and another temperature sensor Ts2 is placed below the threshold and physically below the depth of the Ts1 sensor. The low-level threshold marker (11) does not need to be set by the user, but is automatically set at the base or end tip of the Ts1. The temperature sensor is a thermistor temperature sensor, which is basically a temperature-dependent resistor. It has two identical connection points to a resistor. The thermistor is a negative temperature coefficient (NTC) thermistor, whose resistance decreases with increasing temperature. The thermistor is specifically designed to have a conical end point (inverted triangular shape), as shown in Fig. shown. This special design ensures that any water droplet adhering to the sensor's surface quickly falls due to gravity and does not stick to its surface. The sensor surface is made of a material (molded plastic or stainless steel) with good thermal conductivity and is water-resistant. The terminals of the dual temperature sensors (T-sensors) are connected by long twisted pair wires (5) that run from the bottom to the top of the well. The wire pairs (5) are well-insulated and water-resistant. A small sheath tube (5) is attached to the side of the well to serve as a sheath for the thermistor wire pairs. The tube has a bottom opening for the wire pairs' exit point into the water.This tube serves as a support for the sensors, minimizing their lateral and vertical movement and ensuring that their position / depth in the well does not vary due to environmental disturbances. The other end of the cable pairs terminates in an intelligent electronic monitoring system board (8). The output of the intelligent electronic system is connected to a push-pull solenoid (6), which mechanically actuates and controls the ON / OFF state of the power supply switch for the motors (9). The entire intelligent dry-run monitoring system operates independently of the operation of the submersible motor, and the main power supply line (7) to the motor remains undisturbed in this present invention.

[0020] Fig. shows the part of the intelligent electronic subsystem (8) of the intelligent dry-run monitoring system according to an embodiment of the present invention. The input to the electronic system comes from the dual T-sensors (3) connected in a resistive circuit configuration with a Wheatstone bridge (8a) ( Fig. ). The differential output of this bridge circuit is connected to a front-end circuit with a differential amplifier (8b) with low noise output. The output of the front-end circuit is connected to an A / D converter for analog-to-digital conversion. The ADC output is passed to a microcontroller (8d) with wireless capabilities. The microcontroller executes embedded code that continuously monitors the differential voltage of the Wheatstone bridge and converts it into an equivalent temperature difference between the dual T-sensors. When the water level exceeds the low water threshold (11), the microcontroller code detects an equivalent temperature difference and switches the magnetic circuit ( Fig. ) to shut off the power supply to the motor through the mechanical action of the push-pull magnet. At the same time, the microcontroller also sends an alert message to the farm owner's mobile device via its wireless interface to take further necessary action. The entire intelligent electronic system and its subunits are powered by a regulated DC power supply (8e), which draws its energy from the wall-mounted AC power supply or an external battery. The electronic system is physically located next to the wall-mounted electrical switch of the motors, with the push-pull magnet (6) coming into close contact with the switch, as shown in Fig. shown.

[0021] Fig. shows the configuration of the Wheatstone bridge resistor circuit (8a) according to an embodiment of the present invention. The Wheatstone bridge circuit consists of two resistors R0, which are identical resistors. These resistors are each connected to one terminal of the dual temperature sensors (3) Ts1 and Ts2. The other terminal of the dual T sensors is grounded. The resistance values ​​of the dual T sensors are modeled as R1_ts1 and R1_ts2. The Wheatstone circuit is powered by the DC power supply (8e) of the intelligent electronic system (8), and the differential output Vout is taken via the thermistor sensors R1_ts1 and R1_ts2.

[0022] The principle of low water detection used in the present invention is as follows: When the deep well water is above the threshold mark (11), both sensors Ts1 and Ts2 are immersed in water and their temperatures are equal. Thus, R1_ts1 and R1_ts2 both have the same resistance (R1_ts1=R1_ts2). Therefore, the differential output voltage Vout is zero because the current flow in both circuit branches is equal. When the water level begins to decrease and falls below the threshold (11), Ts1 floats in the air, while Ts2 is still submerged in the water. The air temperature is higher than that of the water. Under this condition, a temperature difference is observed between the two sensors, and therefore R1_ts1 and R1_ts2 have different temperature-dependent resistances, resulting in a finite differential voltage at the output terminals of the Wheatstone circuit.This resistance difference between Ts1 and Ts2 is interpreted as an indication that the water level exceeds the low threshold, which, if left unchecked, can lead to dry running and motor failure. The present invention prevents this situation by processing the voltage difference Vout across the resistors using a front-end circuit and a microcontroller. A mechanical actuation is then performed to interrupt the power supply to the motor unit and send status alerts to the farm owner.

[0023] Fig.shows the magnetic circuit (8d) according to an embodiment of the present invention. The magnetic circuit (8d) connects the microcontroller (8c) to the push-pull magnetic switch (6). The microcontroller is connected to the gate terminal of a power MOSFET switch (8d1) via one of its input / output pins (IO). The output voltage at the IO pins switches the power MOSFET on / off depending on the applied voltage level. The power MOSFET is connected in series with the magnetic switch (6), which is powered by the DC power supply (8e). When the microcontroller applies a voltage to its IO pin, the power MOSFET is turned on, and current flows from the supply to the magnetic switch. The solenoid is essentially an electromagnet (a coil wound on a core similar to an inductor) that is activated when current flows through it, creating a mechanical action of its shaft.This causes the shaft of the mechanical arm to protrude from the solenoid with sufficient force, ultimately turning off the motor power unit (9) immediately. As soon as the microcontroller disables the voltage on its IO pin, the power MOSFET turns OFF, disabling current flow through the solenoid and retracting its shaft of the mechanical arm to its original position. The signal generated by the microcontroller to the power MOSFET is a pulse signal that remains on for a few seconds and then turns off. The mechanical action of the solenoid is similar to the pressing motion of the human finger to turn off the motor main switch, with the only difference being that this is done electromechanically and not manually.The present invention avoids the use of heavy-duty relays, which are cumbersome and costly, by using a solenoid to electromechanically control the motor main switch.

[0024] The operation of the intelligent dry-run monitoring system (10) includes: detecting the low water level threshold using two temperature sensors to prevent dry-run situations in deep wells, using a Wheatstone bridge circuit configuration for differential sensing, amplifying the differential voltage signals with low noise output using a differential amplifier, performing analog-to-digital (A / D) conversion of the amplified voltage signals, processing the digital signals in a wireless microcontroller, continuously monitoring the crossing of the low water level threshold using an embedded program, generating a pulse signal at the IO pin of the microcontroller to enable / disable a power MOSFET and then controlling the mechanical push-pull action of the magnet,to electromechanically switch off the main electrical switch of the engine and prevent dry-running situations of the engines, as well as sending an IOT message to the farm owner's mobile device via the wireless microcontroller regarding the engine running status.

[0025] The step-by-step operation of the system (10) includes: A wall-mounted switch supplies power to the submersible motors located at the bottom of the deep well. When the motor is running, water is pumped through the outlet pipe to the farms for irrigation. As the water level continues to drop and reaches a low threshold (the base or end tip of the temperature sensor Ts1) near the bottom of the well, a differential output voltage signal is generated in the Wheatstone bridge output circuit. This differential signal is generated due to the temperature imbalance of the dual T sensors due to their different physical placement or depth in the deep well. This differential signal is first amplified with a low-noise amplifier, and the signal is A / D converted. The digital signal is then passed to a microcontroller with wireless capability.The embedded program running on the microcontroller processes the digital signals and continuously monitors the digital bitstream for low threshold violations. Once the threshold violation is detected, a magnetic circuit is activated via the microcontroller's IO pin, which controls a power MOSFET switch using a pulse signal. When the magnet is activated, a mechanical pressure movement is generated in the magnet arm shaft, which turns off the motor's main switch. The microcontroller then deactivates the magnet, and the arm shaft retracts to its original position. At the same time, the microcontroller sends an alert about the motor's operating status to the farm owner's mobile device via its wireless IoT functionality.Thus, the present invention enables the farm owner to automatically prevent dry-run situations in deep well motors while they are running unattended for extended periods. Furthermore, the farm owner can conveniently monitor the motor operating status remotely from their mobile device.

[0026] It should be noted that the above-described examples of the present invention are for illustrative purposes only. Although the present invention has been described in connection with a specific example, numerous modifications may be possible without materially departing from the teachings and advantages of the subject matter described herein. Other substitutions, modifications, and changes may be made without departing from the spirit of the present solution. All features disclosed in this specification (including all appended claims, abstracts, and drawings) and / or all steps of a method or process so disclosed may be combined in any combination, except for combinations in which at least some of these features and / or steps are mutually exclusive.Although the embodiments are described herein with various specific embodiments, it will be obvious to one skilled in the art to practice the embodiments herein with modifications. Reference list: 1 deep well 2 submersible motors 3 Double temperature sensors (T-sensors) 4 Twisted pair cable for T-sensors 5 Housing tube for T-sensor cable pairs 6 Push-Pull Solenoid 7 Power supply cables for motors 8 Intelligent electronic system board 8a Wheatstone bridge circuit 8b differential amplifier frontend with integrated A / D converter 8c Wireless Microcontroller 8d Solenoid circuit 8d1 power MOSFET 9 Electrical switch for wall mounting 10 Intelligent dry-run monitoring system 11 Low level threshold marker.

Claims

[1] A dry-run monitoring system (10) comprising: at least two temperature sensors (T-sensors) (3), a housing tube (5) and an intelligent electronic subsystem (8), which in turn consists of a Wheatstone bridge circuit (8a), a low-noise front end (8b), a microcontroller (8c), a magnetic coil circuit (8d), a push-pull magnetic coil (6) and a power supply unit (8e), wherein the two temperature sensors (3) are used to detect low water levels based on their contact / non-contact situation with the water; at least two T-sensors are connected to a Wheatstone bridge circuit configuration (8a) within the intelligent electronic system (8), wherein the differential output signal of the Wheatstone circuit is passed to a low-noise differential amplifier front-end, followed by A / D conversion (8b), the A / D signals then being passed to a microcontroller (8c) with wireless IoT capabilities, the microcontroller continuously checking for threshold violations in the detected differential signals through its embedded program and detecting a low water level or equivalent dry-running condition within the well, wherein upon detection of a low water level condition, the microcontroller activates a magnetic circuit (8d) through a power MOSFET (8d1), which in turn mechanically actuates and controls the push-pull magnet; and, a mechanical actuation of the magnet switches OFF the wall-mounted power supply for the motors (9) and prevents motor running in dry-running condition, while the wireless microcontroller (8c) simultaneously sends warning messages to the user or the farm owner via its IOT interface. [2] The intelligent dry-run monitoring system according to claim 1, wherein the low water level detection is carried out by means of dual temperature sensors (3) suspended at different depths on the bottom of the well, one of them being above and the other below the low water threshold mark (11), the base or end tip of the upper T-sensor (Ts1) being automatically taken as the low water threshold mark (11), wherein when the water exceeds the low water threshold mark, there is a temperature difference between these two sensors because one of them is in contact with the water and the other is not in contact with the water but is suspended in the air, the dual T-sensors being specially designed to have an inverted triangular shape to minimize the adhesion of water droplets to their surface. [3] The intelligent dry-run monitoring system according to claim 1, wherein the differential detection is performed using dual T-sensors and a Wheatstone bridge circuit (8a) to minimize false errors in the detection of low water levels. [4] The intelligent dry-run monitoring system according to claim 1 uses a push-pull solenoid (6) and mechanically actuates the mains power supply (9) of the motor (2), wherein the mechanical actuation of the solenoid (6) substantially mimics the pushing motion of a human finger to turn off the supply. [5] The intelligent dry-run monitoring system of claim 1, wherein the wireless IOT interface of the microcontroller automatically sends remote feedback / alert messages to the farm owner's handheld device when a dry-run situation is detected.

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