Automatic annunciator for detecting water quantity in oil

Abstract

The utility model belongs to the field of hydropower station detection, and particularly relates to an automatic annunciator for detecting water quantity in oil, which comprises an ARM, a digital temperature sensor, a capacitor, a clock circuit, an optical coupler I, a DA conversion circuit, a far-end receiving end, an optical coupler II, an alarm relay and an automatic control loop, the capacitor is connected with the clock circuit, the clock circuit is connected with the optical coupler I, and the optical coupler I is connected with the ARM through one path of I / O port; the digital temperature sensor is connected to the ARM through an I / O port; the capacitor and the digital temperature sensor are in contact with water-containing oil to be measured, a mathematical model is arranged in an ARM control program, the percentage of water in the oil is calculated through frequency, and the percentage of water in the oil is compensated through temperature. According to the utility model, the problem that the error of detecting the percentage of water in oil by a capacitance method is increased due to oil temperature rise is avoided.

Description

Technical Field

[0001] This utility model belongs to the field of hydropower station detection technology, specifically relating to an automated signal device for detecting the amount of water in oil. Background Technology

[0002] If turbine oil and other lubricating oils in hydropower stations are mixed with water for extended periods, it can lead to emulsification, damage to the oil film, and reduced lubrication performance. In severe cases, this can cause wear, vibration, or even malfunctions in the generating units. Furthermore, water reacts with additives in the oil, generating precipitates and gum contaminants, accelerating oil aging and further exacerbating equipment wear. If water seeps into transformer oil in hydropower stations, it will significantly reduce the oil's breakdown voltage, accelerate the aging of insulation fibers, and cause a sharp decline in insulation performance, threatening the safe and stable operation of the power system. Water also accelerates the oxidation reaction of oil, affecting its quality. Simultaneously, water in lubricating oil or grease can damage the protective film on the surface of metal components, causing corrosion and shortening equipment lifespan. Regularly monitoring changes in oil water content allows for the assessment of equipment operating status. Water content detection in hydropower stations is not only an "early warning system" for safe equipment operation but also a core measure to ensure the efficient and stable operation of the power system, extend equipment lifespan, and reduce maintenance costs.

[0003] The core components of a capacitor include internal and external electrodes. When water mixes into the oil, the capacitance value changes significantly due to the large difference in dielectric constants between oil and water. The capacitor generates a high-frequency square wave via a clock circuit. The water content in the oil causes a change in the dielectric constant, thus affecting the capacitance value. This change in capacitance leads to a change in the square wave frequency, and the corresponding water content percentage is calculated by measuring the square wave frequency. However, a problem arises when the turbine operates for extended periods, causing the lubricating oil temperature to rise. This temperature increase alters the dielectric constant of water, increasing the error in detecting the percentage of water in the oil using the capacitance method. A single capacitance method cannot meet the accuracy requirements of the measurement; therefore, a more accurate automated signaling device is urgently needed. Utility Model Content

[0004] The purpose of this invention is to provide an automated signal device for detecting the amount of water in oil, in order to solve the problem in the prior art where the measurement of the percentage of water in oil is affected by changes in oil temperature.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0006] An automated signal device for detecting water content in oil includes an ARM, a digital temperature sensor, a capacitor, a clock circuit, an optocoupler 1, a DA conversion circuit, a remote receiver, an optocoupler 2, an alarm relay, and an automated control loop.

[0007] The capacitor is connected to the clock circuit, which is connected to optocoupler 1. Optocoupler 1 is connected to the ARM through one I / O port. The digital temperature sensor is connected to the ARM through one I / O port.

[0008] The ARM is connected to the alarm relay via optocoupler 2, and the alarm relay is connected to the automatic control circuit.

[0009] The ARM is connected to the DA digital-to-analog converter circuit via the I2C bus, and the DA digital-to-analog converter circuit is connected to the remote receiver.

[0010] The capacitor and digital temperature sensor are in contact with the water-containing oil to be tested. The ARM control program has a mathematical model that calculates the percentage of water in the oil by frequency and compensates for the percentage of water in the oil by temperature.

[0011] Furthermore, the ARM is connected to three digital tubes via I / O ports, which are used to display the percentage of water in the oil, the oil temperature, and the alarm percentage parameters, respectively.

[0012] Furthermore, the ARM has three buttons connected via I / O ports, used for setting alarm points and switching between displaying the percentage of water in the oil and the oil temperature.

[0013] Furthermore, it also includes a power module for converting 24V DC voltage into +5V and +3.3V.

[0014] Furthermore, the ARM processor is an STM32F103T6C8.

[0015] Furthermore, the clock circuit is model NE555.

[0016] Furthermore, the optocoupler 1 is model 6N135, and the optocoupler 2 is model TLP181.

[0017] Furthermore, the digital temperature sensor is model DS18B20.

[0018] Furthermore, the DA digital-to-analog converter circuit includes integrated circuits of model GB8303 and model GL14P04-8.

[0019] Compared with the prior art, the beneficial technical effects of this utility model are as follows:

[0020] This system measures oil temperature using a digital temperature sensor. A capacitor connected to a clock circuit converts the water content in the oil into a high-frequency signal. The mathematical model in the ARM control program calculates the percentage of water in the oil using the frequency, and compensates for this error by adjusting the water content percentage based on temperature variations. Furthermore, a relay is activated based on a set alarm parameter for the water content percentage, and the relay's passive contacts control a remote control circuit to trigger the alarm. A digital-to-analog converter (DA converter) transforms the water content percentage into a 4-20mA signal, which is then connected to a remote receiver. This allows for long-distance transmission and strong anti-interference capabilities, enabling unattended monitoring from a remote location and saving manpower. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the system of this utility model. Detailed Implementation

[0022] The present invention will now be described in detail with reference to specific embodiments.

[0023] like Figure 1 As shown, this utility model discloses an automated signal device for detecting water content in oil, including an ARM, a digital temperature sensor, a capacitor, a clock circuit, an optocoupler 1, a DA conversion circuit, a remote receiver, an optocoupler 2, an alarm relay, an automated control circuit, and a power supply module.

[0024] A capacitor is connected to a clock circuit, which is connected to one of the ARM's I / O ports via optocoupler 1. A digital temperature sensor is connected to one of the ARM's I / O ports. A DA converter is connected to the ARM's I2C bus. The DA converter is used to convert the percentage of water in the oil into a 4-20mA signal and connect it to a remote receiver. One of the ARM's I / O ports is connected to a relay via optocoupler 2. The relay's passive contacts are used to control the remote control circuit. The ARM's 11 I / O ports are connected to a digital tube.

[0025] Example:

[0026] In this embodiment, the ARM is an STM32F103T6C8; the optocoupler 1 is a 6N135, which is a high-speed, high-isolation voltage transistor optocoupler; the clock circuit is an NE555; the capacitor is connected to the optocoupler 1 through the clock circuit; the optocoupler 1 is connected to one IO port of the ARM; the ARM samples the square wave signal of the optocoupler 1 to measure the frequency.

[0027] The digital temperature sensor is connected to one IO port of the ARM, and the ARM communicates with the digital temperature sensor to detect the oil temperature through a single-bus communication method.

[0028] The ARM control program includes a mathematical model that uses frequency to calculate the percentage of water in the oil and uses temperature to compensate for the percentage of water in the oil.

[0029] y = ax 3 +bx 2 +cx+d (1)

[0030] C = ky (2)

[0031] y: frequency, x: oil temperature, a, b, c, d: coefficients corresponding to the percentage of water in the standard oil solution (e.g., 0%, 3%, 5%, 10%), C: percentage of water in the oil, y: frequency, k: proportionality coefficient.

[0032] Test in solutions with water percentage in standard oil (e.g., 0%, 3%, 5%, 10%) to obtain corresponding frequency and temperature change curves. Based on the curves, the coefficients a, b, c, and d in the temperature compensation formula (1) are different for different water percentage solutions in different oils.

[0033] At the same oil temperature, the frequencies measured in solutions with different proportions of water content in the oil are different. Assuming that at the same oil temperature, within a certain proportion range (e.g., 3% to 5%), the water content in the oil and the frequency have a linear relationship (Formula (2)), the more intervals are divided, the closer the relationship is to linearity.

[0034] Based on the different percentages of water in the oil (e.g., 0%, 3%, 5%, 10%), the corresponding coefficients a, b, c, and d are substituted into formula (1). The measured oil temperature is substituted into formula (1) for temperature compensation to obtain the corresponding frequency. Then, the coefficient k in formula (2) is obtained within the corresponding frequency ratio range (e.g., 3% to 5%). Based on the frequency measured by the signal device, it is determined which ratio range (e.g., 3% to 5%) it belongs to, and the corresponding coefficient k is obtained. The coefficient k is substituted into formula (2), and the frequency measured by the signal device is substituted into formula (2) to obtain the percentage of water in the oil at a certain oil temperature.

[0035] The ARM processor drives three digital tubes through an 11-channel I / O port driver circuit. Seven of the I / O ports control the seven-segment display of the digital tubes, while the other three I / O ports control the lighting and extinguishing of the three digital tubes. The digital tube display uses a scanning method.

[0036] The ARM processor connects to the DA (digital-to-analog) converter circuit via an I2C bus, converting the percentage of water in the oil into a 4-20mA signal for transmission to the remote receiving end. The DA converter circuit consists of integrated circuits of model GB8303 and model GL14P04-8.

[0037] The relay model is G6S-2, the optocoupler 2 model is TLP181, and the ARM's 1 IO port is connected to the relay through optocoupler 2. TLP181 is an optocoupler with high isolation performance. The ARM controls the relay operation, and the relay's passive contacts control the remote control circuit.

[0038] The power module converts DC 24V to +5V and +3.3V. The +5V provides the operating voltage for NE555, DS18B20, GL14P04-8 and GP8303, the 3.3V provides the operating voltage for ARM, and the +24V provides the operating voltage for relays.

[0039] The working principle of this utility model is as follows:

[0040] After the signal device is powered on, it is initialized and parameters are set, and the alarm point for the percentage of water in the oil is set.

[0041] The capacitor is in full contact with the oil and connected to the clock circuit. The clock circuit converts the capacitance value of the capacitor into a high-frequency signal. The frequency signal is filtered and shaped by optocoupler 1 into a square wave signal. Optocoupler 1 is connected to AMR through one I / O port. AMR measures the square wave frequency through its internal event capture unit.

[0042] The digital temperature sensor is connected to the AMR via one I / O port. The digital temperature sensor directly converts the oil temperature into a digital electrical signal and transmits it to the AMR in a single-bus protocol manner.

[0043] The mathematical model in the ARM control program uses frequency to calculate the percentage of water in the oil and uses temperature to compensate for the percentage of water in the oil.

[0044] When the calculated percentage of water in the oil is greater than or equal to the set alarm percentage value, the ARM drives the optocoupler II through one IO interface, the optocoupler drives the relay to operate, and the relay passively controls the automation control circuit.

[0045] The ARM processor drives three digital tubes via 11 I / O ports. Seven of these I / O ports drive the seven signal lines (a, b, c, d, e, f, g) of the digital tubes to control the eight LED segments of the digital tubes to light up or turn off, thus forming numbers and symbols. The other three I / O ports control the lighting and turning off of one of the three digital tubes. The display mode of the three digital tubes is a cyclic scanning method in which the first to the third LED segments light up and turn off in sequence. The three digital tubes are used to display parameters such as the percentage of water in the oil, oil temperature, and alarm percentage.

[0046] The ARM is connected to the DA digital-to-analog converter circuit via the I2C bus. The ARM transmits the water content percentage signal in the oil to the DA digital-to-analog converter circuit via the I2C bus protocol. The DA digital-to-analog converter circuit converts the water content percentage in the oil into a corresponding 4-20mA signal and transmits it to the remote receiver for remote monitoring.

[0047] The content of this utility model is not limited to the embodiments listed. Any equivalent modifications made by those skilled in the art to the technical solution of this utility model after reading this utility model specification shall be covered by the claims of this utility model.

Claims

1. An automated signaler for detecting the amount of water in oil, characterized by: The application relates to an ARM, a digital temperature sensor, a capacitor, a clock circuit, a photo-coupler 1, a DA conversion circuit, a remote receiving end, a photo-coupler 2, an alarm relay, and an automatic control loop. The capacitor is connected with the clock circuit, the clock circuit is connected with the photo-coupler 1, and the photo-coupler 1 is connected with the ARM through an I / O port; the digital temperature sensor is connected with the ARM through an I / O port; The ARM is connected with the alarm relay through the photo-coupler 2, and the alarm relay is connected with the automatic control loop; The ARM is connected with the DA digital-analog conversion circuit through an I2C bus, and the DA digital-analog conversion circuit is connected with the remote receiving end; wherein the capacitor and the digital temperature sensor are in contact with the water-containing oil to be measured, a mathematical model is set in an ARM control program to calculate the water content percentage in the oil through frequency, and the water content percentage in the oil is compensated by temperature.

2. The automated signaler for detecting the amount of water in oil as claimed in claim 1 wherein: The ARM is connected with three NMD displays through I / O ports, and the three NMD displays are respectively used for displaying the water content percentage in the oil, the oil temperature and the alarm percentage parameters.

3. The automated signaler for detecting the amount of water in oil as claimed in claim 2 wherein: The ARM is connected with three keys through I / O ports, and the three keys are used for setting the alarm point and switching the water content percentage in the oil and the oil temperature display.

4. The automated signaler for detecting the amount of water in oil as claimed in claim 3 wherein: The application further comprises a power module which is used for converting 24V direct current voltage into +5V and +3.3V.

5. The automated signaler for detecting the amount of water in oil as claimed in claim 4 wherein: The model of the ARM is STM32F103T6C8.

6. The automated signaler for detecting the amount of water in oil as claimed in claim 4 wherein: The model of the clock circuit is NE555.

7. The automated signaler for detecting the amount of water in oil as claimed in claim 4 wherein: The model of the photo-coupler 1 is 6N135, and the model of the photo-coupler 2 is TLP181.

8. The automatic water-in-oil signaler of claim 4, wherein: The model of the digital temperature sensor is DS18B20.

9. The automatic water-in-oil signaler of claim 4, wherein: The DA digital-analog conversion circuit comprises integrated circuits with the models of GB8303 and GL14P04-8.

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