Ultrasonic transformer oil level measuring device

Abstract

The utility model belongs to the technical field of power equipment monitoring, and particularly relates to an ultrasonic transformer oil level measuring device, which comprises a cylindrical shell, an oil level sensor, an oil level sensor and an oil level sensor, the ultrasonic sensor is embedded in the lowest position of the cambered surface upper layer, the two magnets are embedded in the two sides of the cambered surface upper layer, and the temperature sensor is installed in the shell and close to the ultrasonic sensor; and the control circuit is arranged in the cylindrical shell and is connected with the temperature sensor and the ultrasonic sensor. The problems that an existing transformer oil level measuring technology is low in precision, poor in reliability, insufficient in adaptability and the like are solved, a reasonable installation position is adopted so that the device can still work stably in complex environments such as high voltage and strong electromagnetic interference, and the adopted overall structure ensures the accuracy of measured data.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of electric power equipment monitoring, especially relates to an ultrasonic transformer oil level measuring device. BACKGROUND

[0002] With the high-speed development of social economy, the science and technology level of the electric power industry has improved significantly, and the transformer, as a key equipment of the electric power system, plays an indispensable role in the process of electric power transmission and distribution, and it can convert high-voltage electric energy into voltage levels suitable for different power consumption requirements, and ensure that electric energy is safely and efficiently transmitted to the user end. The transformer oil not only plays an insulating role inside the transformer, preventing short circuit faults between the winding and the core and between the windings, but also dissipates the heat generated by the core and the winding through convection, maintaining the normal working temperature of the transformer.

[0003] The traditional transformer oil level measurement method mainly includes the oil level gauge method. The oil level gauge is usually designed based on mechanical structure principles, such as the float type oil level gauge, which moves the connecting rod or pointer by the float rising and falling with the oil level, thereby displaying the oil level height on the scale disc. However, this traditional measurement method faces a series of problems. During long-term operation, mechanical components are prone to wear, corrosion, and thermal expansion and contraction caused by changes in environmental temperature, which leads to a decrease in the matching precision between components and easily causes jamming, resulting in gradually increasing measurement errors or even eventual failure. Moreover, its measurement precision is relatively low, which cannot meet the strict requirements of modern electric power systems for transformer fine management and early fault warning. For example, in some places with extremely high requirements for power quality, such as data centers and precision electronic manufacturing plants, small changes in oil level may indicate potential internal faults of the transformer, and the traditional oil level gauge cannot timely and accurately capture these changes. INVENTION CONTENTS

[0004] The technical problem to be solved by the utility model is to provide an ultrasonic transformer oil level measuring device, which solves the problems of low precision, poor reliability, and insufficient adaptability in existing transformer oil level measurement technology.

[0005] The utility model is implemented in the following way,

[0006] An ultrasonic transformer oil level measuring device, the device comprises: a cylindrical shell, the shell has a concave arc upper layer, the arc upper layer is attached to the bottom of the transformer oil pillow, an ultrasonic sensor is embedded in the lowest part of the arc upper layer, two magnets are embedded on both sides of the arc upper layer, a temperature sensor is installed in the shell near the ultrasonic sensor, a control circuit is arranged in the cylindrical shell and connected with the temperature sensor and the ultrasonic sensor.

[0007] Further, the control circuit comprises: a signal conditioning circuit connected with the output end of the ultrasonic sensor, the signal conditioning circuit is connected to the RS485 interface circuit through an RS485 bus, the RS485 interface circuit is connected with the wireless unit through the RS485 bus, the wireless unit is connected with the MCU controller through a UART serial interface; the temperature sensor is connected with the MCU controller through an SDA line; and the output end of the MCU controller is connected with the alarm unit.

[0008] Further, the wireless unit is connected with the MCU controller through the UART serial interface, which comprises that a UART sending pin TX of the MCU controller is directly connected with a UART receiving pin RX of the wireless unit through a wire, a UART receiving pin RX of the MCU controller is connected with a UART sending pin TX of the wireless unit, and the MCU controller and the wireless unit share a common ground pin GND.

[0009] Further, the alarm unit comprises an audible and light alarm, the audible and light alarm comprises a light-emitting diode and a buzzer, and the audible and light alarm is connected with the MCU controller through a driving circuit.

[0010] Further, dual power supply is adopted, the dual power supply comprises a main power supply and a backup power supply, the main power supply is powered from a secondary side of a transformer, the backup power supply is a lithium battery or a super capacitor, and the main power supply and the backup power supply are automatically switched to the backup power supply for power supply when the main power supply is powered off or fails.

[0011] Further, the temperature sensor adopts a thermistor or a thermocouple.

[0012] Further, the power supply provides stable power supply for the temperature sensor, a current-limiting resistor R1 is connected in series between the power supply and the temperature sensor, one end of the temperature sensor is connected to the current-limiting resistor, the other end is connected to an input pin of an A / D converter, a measurement loop is formed, and an output end of the A / D converter is connected to the MCU controller.

[0013] Compared with the prior art, the utility model has the beneficial effect that:

[0014] The utility model adopts reasonable installation position to make device still can stable work under high pressure, strong electromagnetic interference and other complex environment, and the whole structure that adopts ensures the accuracy of measurement data. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is structural schematic diagram of ultrasonic transformer oil temperature measuring device;

[0016] Figure 2 It is structure block diagram of control circuit;

[0017] Figure 3 It is connection relation diagram of temperature sensor. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical scheme and advantages of the utility model clearer and more understandable, the utility model will be further described in detail below in combination with embodiments. It should be understood that the specific embodiments described herein are only used to explain the utility model and not to limit the utility model.

[0019] Referring to Figure 1 As shown in the structural diagram of the ultrasonic transformer oil temperature measuring device, the ultrasonic sensor 1, the magnet 2, the shell 3, the temperature sensor 4, and the transformer oil pillow 5. The shell is a cylindrical shell with a concave upper arc surface that is attached to the bottom of the transformer oil pillow. The ultrasonic sensor is embedded in the lowest part of the upper arc surface, and the two magnets are embedded on both sides of the upper arc surface. The temperature sensor is installed in the shell near the ultrasonic sensor. The control circuit is set in the cylindrical shell and connected with the temperature sensor and the ultrasonic sensor. The ultrasonic sensor 1 is used to measure the height of the oil level in the oil pillow. The distance from the oil surface to the ultrasonic sensor is determined by transmitting ultrasonic waves and receiving reflected waves, and then the oil level height is obtained. Embedding it in the device's arc upper layer facilitates the transmission and reception of ultrasonic waves. The magnets 2 are embedded on both sides of the device's arc surface as a kind of fixing device. The shell 3 is made of metal, and the upper surface is designed in an arc shape so that the arc surface exactly fits the transformer oil pillow 5. The shell of the entire ultrasonic transformer oil level measuring device is attracted to the surface of the transformer's oil pillow by the magnetic attraction method. The temperature sensor 4 is used to measure the temperature of the transformer oil. The temperature of the transformer oil is an important operating parameter that affects the physical properties of the oil (such as density, viscosity, etc.), which in turn affects the measurement of the oil level. By monitoring the oil temperature, the temperature compensation of the oil level measurement result can be performed to improve the accuracy of the measurement. Here we use a platinum resistance temperature sensor. First, the ultrasonic sensor 1 is firmly installed in the selected position by the device shell magnet 2 to observe whether the magnet 2 can work normally and ensure that it will not displace during operation. According to the power supply requirements of the sensor, provide appropriate power connection, start the ultrasonic sensor 1, send test ultrasonic signal, and check the reception signal. According to the strength and time delay of the received signal, adjust the position and parameters of the sensor to ensure accurate measurement of the oil level. Connect the signal line of the temperature sensor 4 to the MCU control circuit for temperature calibration, compare its measurement value with the known temperature, adjust the measurement circuit or sensor parameters to ensure the accuracy of temperature measurement. At the same time, the ultrasonic sensor 1 and the temperature sensor 4 are operated to check whether the data acquisition and processing of the two are normal.

[0020] Referring to Figure 2As shown, the ultrasonic transformer oil level measurement system mainly consists of two parts, one is that the ultrasonic sensor 1 is adsorbed on the transformer oil pillow 5 through the magnet 2 embedded in the device shell, and the other is the control circuit. The ultrasonic sensor 1 is equipped with an independent signal conditioning circuit, which includes a preamplifier, a filter and the like, for amplifying and filtering the weak ultrasonic echo signal received by the sensor, thereby improving the signal quality. After signal conditioning, the signals of multiple sensors are connected to the RS485 interface circuit through the RS485 bus. The RS485 interface circuit realizes signal aggregation and conversion, converts the data of the ultrasonic sensor into a format consistent with the RS485 communication protocol, and then connects with the wireless unit through the RS485 bus. The RS485 bus uses twisted pair transmission, and the characteristic impedance of the twisted pair matches the transmission signal, reducing signal reflection and enhancing transmission stability. In the transformer oil level measurement device, due to the complex environment around the transformer, various electromagnetic interferences exist, and the RS485 bus connection can effectively ensure that the oil level data collected by the ultrasonic sensor is accurately transmitted to the wireless unit. Then the wireless unit is connected to the MCU controller through the UART serial interface. In the connection between the wireless unit and the UART serial interface of the MCU controller, the UART transmit pin TX of the MCU controller is directly connected to the UART receive pin RX of the wireless unit through a wire, and the UART receive pin RX of the MCU controller is connected to the UART transmit pin TX of the wireless unit, while they share a common ground pin GND. This cross-connection method ensures that data can be correctly transmitted between the two devices. When the MCU controller sends data to the wireless unit, the data is output from the UART transmit pin TX of the MCU controller and enters the UART receive pin RX of the wireless unit through a wire; when the wireless unit sends data to the MCU controller, the data is output from the UART transmit pin TX of the wireless unit and flows to the UART receive pin RX of the MCU controller. The connection of the ground pin provides a stable reference level for the signal, ensuring the integrity and accuracy of the signal. When the MCU controller needs to send data to the wireless unit, the data is output bit by bit from the UART transmit pin TX according to the pre-set UART data format and baud rate. The data is transmitted in a serial manner on the transmission line, and the UART receive pin RX of the wireless unit continuously monitors the transmission line. Once the start bit is detected, the wireless unit starts receiving data bits and performs error checking according to the configured checking method. If the checking is passed, the wireless unit stores the received data in the internal buffer and performs subsequent processing according to the communication protocol, such as packaging data for sending out through the wireless communication module. When the wireless unit sends data to the MCU controller, the data is output from the UART receive pin TX, and the UART receive pin RX of the MCU controller receives the data.

[0021] The alarm unit comprises an audible and visual alarm, which is composed of a light-emitting diode (LED) and a buzzer and the like. When the MCU controller sends a trigger signal, the audible and visual alarm is connected to the MCU controller through a driving circuit. After receiving the signal, the audible and visual alarm makes the LED flicker and light, and the buzzer emits a loud sound alarm signal, so as to timely remind the on-site operation and maintenance personnel or the staff of the remote monitoring center to pay attention to the abnormal situation, so that corresponding measures are taken for processing, and accidents are effectively prevented from occurring and expanding. The connection mode between the temperature sensor and the MCU controller comprises: adopting an I2C, an analog input temperature sensor as a slave device, and connecting the temperature sensor to the MCU controller as a master device through two lines (a data line SDA and a clock line SCL). The temperature sensor transmits the measured temperature data to the MCU controller through the SDA line. The measurement data of the temperature sensor effectively improves the measurement accuracy and reliability of the whole oil level measuring device, and provides more accurate monitoring data for the safe operation of the transformer. The device adopts a dual power supply mode, a main power supply is taken from the secondary side of the transformer, and after being processed by a voltage reduction, rectification, filtering and voltage stabilization circuit, the device is powered. A backup power supply is a large-capacity backup lithium battery or a super capacitor, which automatically switches to the backup power supply for power supply when the main power supply is powered off or fails.

[0022] Figure 3 As shown, the temperature sensor adopts a platinum resistance temperature sensor PT100, and a power supply provides stable power supply for the platinum resistance temperature sensor PT100. A current limiting resistor R1 is connected in series between the power supply and the platinum resistance temperature sensor PT100. The main function of the current limiting resistor R1 is to limit the current flowing through the platinum resistance, so as to prevent excessive current from causing the platinum resistance to heat up, thereby affecting the accuracy of temperature measurement. Because the resistance value of the platinum resistance will change with temperature, if the heat generated by excessive current interferes with the original temperature response characteristic of the platinum resistance. One end of the platinum resistance temperature sensor PT100 is connected to the current limiting resistor, and the other end is connected to the input pin of the A / D converter, forming a measurement loop. When the temperature changes, the resistance value of the platinum resistance temperature sensor PT100 changes accordingly. According to Ohm's law U = IR, in the case of known power supply voltage and current limiting resistor resistance value, the current in the loop will change, thereby causing the voltage across the platinum resistance temperature sensor PT100 to change. This voltage change is an analog signal reflecting the change in temperature, and the A / D converter converts the analog signal into a digital signal and transmits it to the MCU controller.

[0023] As described above, the embodiments of the present application are described in detail, but as long as the essence does not deviate from the invention point and effect of the present application, there are many deformations, which are obvious to those skilled in the art. Therefore, such deformation examples are also entirely included in the protection scope of the present application.

[0024] The above merely describes preferred embodiments of the present application and is not intended to limit the present application, and any modification, equivalent replacement, and improvement within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An ultrasonic transformer oil level measuring device, characterized by, The device comprises a cylindrical shell, the shell has a concave arc upper layer, the arc upper layer is attached to the bottom of the transformer oil pillow; an ultrasonic sensor is embedded in the lowest part of the arc upper layer, two magnets are embedded on both sides of the arc upper layer, a temperature sensor is installed in the shell near the ultrasonic sensor; a control circuit is arranged in the cylindrical shell and connected with the temperature sensor and the ultrasonic sensor.

2. An ultrasonic transformer oil level measuring device according to claim 1, characterized in that The control circuit comprises a signal conditioning circuit connected with the output end of the ultrasonic sensor, the signal conditioning circuit is connected to an RS485 interface circuit through an RS485 bus, the RS485 interface circuit is connected with a wireless unit through the RS485 bus, the wireless unit is connected with an MCU controller through a UART serial interface; the temperature sensor is connected with the MCU controller through an SDA line; the output end of the MCU controller is connected with an alarm unit.

3. The ultrasonic transformer oil level measuring device according to claim 2, characterized in that, The wireless unit is connected with the MCU controller through the UART serial interface, which comprises that the UART sending pin TX of the MCU controller is directly connected with the UART receiving pin RX of the wireless unit through a wire, the UART receiving pin RX of the MCU controller is connected with the UART sending pin TX of the wireless unit, and the MCU controller and the wireless unit share a common ground pin GND.

4. The ultrasonic transformer oil level measuring device according to claim 2, characterized in that, The alarm unit comprises an audible and visual alarm, the audible and visual alarm comprises a light-emitting diode and a buzzer, and the audible and visual alarm is connected with the MCU controller through a driving circuit.

5. The ultrasonic transformer oil level measuring device according to claim 2, characterized in that, Dual power supply is adopted, which comprises a main power supply and a backup power supply, the main power supply is powered from the secondary side of the transformer, the backup power supply is a lithium battery or a super capacitor, and the main power supply and the backup power supply are automatically switched to the backup power supply for power supply when the main power supply is powered off or fails.

6. The ultrasonic transformer oil level measuring device of claim 1, wherein, The temperature sensor adopts a thermistor or a thermocouple.

7. The ultrasonic transformer oil level measuring device of claim 1, wherein, The power supply provides stable power supply for the temperature sensor, a current limiting resistor R1 is connected in series between the power supply and the temperature sensor, one end of the temperature sensor is connected to the current limiting resistor, and the other end is connected to the input pin of the A / D converter, forming a measurement loop, and the output end of the A / D converter is connected to the MCU controller.

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