Description:

TECHNICAL FIELD
The present invention relates to power transformers, and more particularly, to a monitoring of conservator oil level in a power transformer used in Low Voltage/Medium Voltage/High Voltage/Extra High Voltage/Ultra High Voltage electrical system.

BACKGROUND OF THE INVENTION
Remote monitoring of conservator oil level in a power transformer is essential to ensure safe and reliable operation of the transformers. On the contrary, continuous monitoring of the same is impossible in an unmanned station. All the power transformers fitted with conventional Magnetic Oil Gauge, MOG, provides low oil level alarm only when the conservator tank gets empty. To get the analogue value, one must visit the transformer to physically inspect.

The best available solution provides digital data from MOG through stage contacts only. However, existing prior art solutions does not facilitate asset managers to monitor oil level in analogue form.

Therefore, in view of the exiting prior art, there is a dire need for a system and method for monitoring of conservator oil level in a power transformer, and communicating the oil level in analogue form in terms of percentage value, for remote access by the onsite technical people.

SUMMARY OF THE INVENTION
The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the present invention. It is not intended to identify the key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concept of the invention in a simplified form as a prelude to a more detailed description of the invention presented later.

An object of the present disclosure is to provide a system for monitoring of conservator oil level in a power transformer, and communicating the oil level in analogue form in terms of percentage value, for remote access by the onsite technical people.

According to an aspect, a remote monitoring system for liquid level in a liquid filled chamber, said system comprising: a float operably placed inside the liquid filled chamber, said float is adapted to hover over the top surface of the liquid; a driving magnet operably coupled to the float, wherein any change in level of the float according to a change in level of the liquid in the liquid filled chamber adaptively rotates the driving magnet, and a rotational movement of the driving magnet is adapted to rotate a driven magnet coupled to the driving magnet; a liquid level gauge having a potentiometer coupled with a shaft, said shaft being coupled to the driven magnet and adapted to rotate according to a rotational movement of the driven magnet and the driving magnet, wherein the rotational movement of the shaft changes an output of a coupled potentiometer and a local indicator, said potentiometer being adapted to communicate the liquid level in the liquid filled chamber, in analogue form in terms of percentage value.

According to an embodiment, the monitoring system is adapted for remote monitoring of conservator oil level in a Magnetic Oil Gauge, MOG, in a power transformer.

According to an embodiment, in the monitoring system, the potentiometer is adapted to communicate the oil level in the MOG, in analogue form in terms of percentage value.

According to an embodiment, the monitoring system comprises a 5V DC source obtained from 230 V AC through a converter operably coupled to terminals of the potentiometer, and a wiper contact moves over a carbon film depending upon the liquid level/conservator oil level inside the liquid filled chamber/a conservator tank.

According to an embodiment, the monitoring system is configured to measure an output voltage across wiper contact and the positive terminal of the potentiometer.

According to an embodiment, the monitoring system is configured to measure an output voltage varying from 1V to 4V depending on the movement of the wiper contact where 1V is equivalent to 0%, and 4V is equivalent to 100 % filling of the liquid filled chamber/the conservator tank.

According to an embodiment, the monitoring system comprises an analogue to Digital Converter (ADC) which takes its auxiliary power from a 12V power source backed up by a battery, said ADC is configured to convert the analogue voltage output from potentiometer terminals to digital voltage output.

According to an embodiment, the monitoring system further comprises a GSM/GPRS modem configured to transmit the digital voltage output to a cloud data storage server.

According to an embodiment, the monitoring system is configured to measure the percentage of output voltage to easily determine the percentage value of the chamber is filled with the liquid/oil, and the system is configured to generate an alarm by sending SMS to designated mobile numbers when the percentage value will go down to a preset value.

Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.

BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
The above and other aspects, features and advantages of the embodiments of the present disclosure will be more apparent in the following description taken in conjunction with the accompanying drawings, in which:

Figures 1 illustrates a schematic diagram of a system for monitoring of conservator oil level in a power transformer, according to an embodiment of the present invention.

Figure 2 illustrates a schematic diagram for data transmission protocol of Remote communicable MOG, according to an embodiment of the present invention.

Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may have not been drawn to scale. For example, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help to improve understanding of various exemplary embodiments of the present disclosure. Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures.

DETAILED DESCRIPTION OF THE INVENTION
The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary implementations of the invention. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary.

Features that are described and/or illustrated with respect to one implementation may be used in the same way or in a similar way in one or more other implementations and/or in combination with or instead of the features of the other implementations.

According to an embodiment, the remote oil level monitoring system uses a Magnetic Oil Gauge (MOG) having a 10 kΩ potentiometer coupled with its shaft. It is capable of delivering exact analogue output. 1- 4-volt linear output of the potentiometer makes it suitable for a wide range of application.

According to an embodiment, the system facilitates remotely monitor the oil level of the transformer through this device. The output is in analogue (percentage) value. It is capable to communicate with both the microcontroller based and PLC based module. It is also possible to use this device in any other liquid filled plant / equipment.

As shown in Fig. 1, a float being fitted inside a liquid chamber, always hovers over the top surface of the liquid. Any change in the level of liquid level results into the rotational movement of a driving magnet. Any movement in the driving magnet causes the movement of a coupled driven magnet, thus causing rotational movement of a shaft. Rotational movement of the shaft changes the output of a coupled potentiometer and a local indicator.

According to an exemplary implementation, as shown in Fig 2, a 5V DC power source is obtained from 230V AC power source through a converter and fed to potentiometer terminals, and a wiper contact moves over a carbon film depending upon the oil level inside the conservator tank. Output voltage is measured across wiper contact and the positive terminal of the potentiometer. This output voltage can be varied from 1V to 4V depending on the movement of the wiper contact where 1V is equivalent to 0% & 4V is equivalent to 100 % filling of the conservator. The analogue voltage output from potentiometer terminals is converted to digital one by an analogue to Digital Converter (ADC) which takes its auxiliary power from a 12V power source backed up by a battery. The digital output is then transmitted to Cloud through a GSM modem. The data in the form of percentage of the conservator volume filled is fetched from the Cloud by 2 inter-communicable servers and displayed in a Dashboard of a web application. By measuring the percentage of output voltage, it can be easily concluded “what percent of the chamber is filled with the oil”. It will also generate an alarm through sending SMS to the designated mobile numbers when the percentage value will go down to a preset value.

According to an implementation, stable & harmonic free DC voltage with a magnitude between 1 to 4 volt is required to ensure proper and flawless measurement.

Some of the non-limiting advantages of the system for monitoring of conservator oil level in a power transformer in analogue form are:
1. Remotely monitoring transformer conservator oil level.
2. Also, possible to monitor the level of any liquid filled plant / equipment.
3. It enables maintenance people to continuously monitor the oil level as percentage of the conservator volume
4. Appropriate action can be taken even before the alarm generates for “Low Oil level”.
5. This reduces the wastage of transformer oil as prompt action can be taken well before the generation of alarm
6. Temperature-oil volume characteristics can be easily obtained as continuous data is available.
7. Smart system which will eliminate tripping of the transformer due to loss of oil, to ensure uninterrupted power supply to the consumers as far as oil level of the transformer is concerned.

Although a system for monitoring of conservator oil level in a power transformer in analogue form has been described in language specific to structural features and/or methods, it is to be understood that the implementations disclosed in the above section are not necessarily limited to the specific features or methods or devices described. Rather, the specific features are disclosed as examples of implementations of the system for monitoring of conservator oil level in a power transformer in analogue form.
, Claims:
1. A remote monitoring system for liquid level in a liquid filled chamber, said system comprising:
a float operably placed inside the liquid filled chamber, said float is adapted to hover over the top surface of the liquid;
a driving magnet operably coupled to the float, wherein any change in level of the float according to a change in level of the liquid in the liquid filled chamber adaptively rotates the driving magnet, and a rotational movement of the driving magnet is adapted to rotate a driven magnet coupled to the driving magnet;
a liquid level gauge having a potentiometer coupled with a shaft, said shaft being coupled to the driven magnet and adapted to rotate according to a rotational movement of the driven magnet and the driving magnet,
wherein the rotational movement of the shaft changes an output of a coupled potentiometer and a local indicator, said potentiometer being adapted to communicate the liquid level in the liquid filled chamber, in analogue form in terms of percentage value.

2. The monitoring system as claimed in claim 1, wherein the system is adapted for remote monitoring of conservator oil level in a Magnetic Oil Gauge, MOG, in a power transformer.

3. The monitoring system as claimed in claim 2, wherein the potentiometer is adapted to communicate the oil level in the MOG, in analogue form in terms of percentage value.

4. The monitoring system as claimed in claims 1-2, wherein the system comprises a 5V DC source obtained from 230 V AC through a converter operably coupled to terminals of the potentiometer, and a wiper contact moves over a carbon film depending upon the liquid level/conservator oil level inside the liquid filled chamber/a conservator tank.

5. The monitoring system as claimed in claim 1, wherein the system is configured to measure an output voltage across wiper contact and the positive terminal of the potentiometer.

6. The monitoring system as claimed in claim 1, wherein the system is configured to measure an output voltage varying from 1V to 4V depending on the movement of the wiper contact where 1V is equivalent to 0%, and 4V is equivalent to 100 % filling of the liquid filled chamber/the conservator tank.

7. The monitoring system as claimed in claim 1, wherein the system comprises an analogue to Digital Converter (ADC) which takes its auxiliary power from a 12V power source backed up by a battery, said ADC is configured to convert the analogue voltage output from potentiometer terminals to digital voltage output.

8. The monitoring system as claimed in claim 7, wherein the system comprises a GSM/GPRS modem configured to transmit the digital voltage output to a cloud data storage server.

9. The monitoring system as claimed in claim 1, wherein the system is configured to measure the percentage of output voltage to easily determine the percentage value of the chamber is filled with the liquid/oil, and the system is configured to generate an alarm by sending SMS to designated mobile numbers when the percentage value will go down to a preset value.