03-11-2016, 03:58 PM
1464163498-Minorprojectreport.doc (Size: 283 KB / Downloads: 4)
ABSTRACT
The transformer is a critical item of equipment in a power system and its correct functioning is essential to the reliable operation of the system. This system utilizes existing communication network call IOT technology. This system able to provide following benefits for utilities: Over Temperature, Voltage, Oil level fault. to monitor and control these parameters and also transformer capacity can be utilized more efficiently and the control of power quality can be improved. If there is any problem in these parameters of the transformer the System can made shut down by sending command to the controlling and monitoring system through GPS. However, on-line data on the conditions of distribution transformer substations are currently not often available for remote diagnosis. For example, the information on the loading of distribution transformer substations is not in real time, but is limited and based only on technical checks performed few times a year by visiting maintenance electricians.
Introduction
Transformer is a critical item of equipment in power systems and its correct functioning is essential to the reliable operation of the system. It is therefore, necessary to monitor the operating condition and performance of distribution transformers in order to avoid or reduce disruption due to sudden unexpected failure. It also helps to save running costs by optimizing maintenance schedules. Several monitoring systems for power transformers have been developed but not for distribution transformers. Generally, the trend of transformer monitoring systems (TMS) is from data acquisition to data interpretation to give clear information to the operator. The distribution network will entirely be controlled automatically. The reliability of operation of distribution networks can be increased by using automatic monitoring systems for transformers – not only for power transformers but also for distribution transformers. Remote monitoring can provide selective sharing of data among multiple sites in the most efficient and cost effective manner.
Objective
The objective of this project is developing an DG/transformer monitoring system using IOT. This system provides the data about the transformer parameters with one access to the internet. The system reduces time consumption and human efforts . Remote monitoring can provide selective sharing of data among multiple sites in the most efficient and cost effective manner.
Motivation
Now a days we see that the conditions of transformer substations are currently not often available for remote diagnosis. For example, the information on the loading of distribution transformer substations is not in real time, but is limited and based only on technical checks performed few times a year by visiting maintenance electricians. So to over come this problem we have come up with the solution by Monitor the operating condition and performance of DG/transformers using wireless network.
Components Used
Power supply:
This section is meant for supplying Power to all the sections mentioned above. It basically consists of a Transformer to step down the 230V ac to 12 ac followed by diodes. Here diodes are used to rectify the ac to dc. After rectification the obtained rippled dc is filtered using a capacitor Filter. A positive voltage regulator is used to regulate the obtained dc voltage.
A transformer is an electrical device which is used to convert electrical power from one electrical circuit to another without change in frequency. Transformers convert AC electricity from one voltage to another with little loss of power. Transformers work only with AC and this is one of the reasons why mains electricity is AC. Most power supplies use a step-down transformer to reduce the dangerously high mains voltage to a safer low voltage. The input coil is called the primary and the output coil is called the secondary. There is no electrical connection between the two coils; instead they are linked by an alternating magnetic field created in the soft-iron core of the transformer. The two lines in the middle of the circuit symbol represent the core.
Rectifier
A circuit which is used to convert AC to DC is known as RECTIFIER. The process of conversion AC to DC is called “rectification”
Filtering significantly increases the average DC voltage to almost the peak value (1.4 × RMS value). To calculate the value of capacitor©,
C = ¼*√3*f*r*Rl
Where,
f = supply frequency,
r = ripple factor,
Rl = load resistance
Note: In our circuit we are using 1000μF. Hence large value of capacitor is placed to reduce ripples and to improve the DC component.
Features:
1. Output Current up to 1A
2. Output Voltages of 5, 6, 8, 9, 10, 12, 15, 18, 24V
3. Thermal Overload Protection
4. Short Circuit Protection
5. Output Transistor Safe Operating Area Protection
Switching circuit
The TPS2049 power-distribution switch is intended for applications where heavy capacitive loads and short circuits are likely to be encountered. This device incorporates a 600-mΩ N-channel MOSFET power switch for power-distribution systems that require only one power distribution path. The switch is controlled by a logic enable input. Gate drive is provided by an internal charge pump designed to control the power-switch rise times and fall times to minimize current surges during switching. The charge pump requires no external components and allows operation from supplies as low as 2.7V.
Under voltage Protection
In under voltage protection transformer provides the protection from the under voltage. When supply system has low voltage than the rated of transformer then under voltage protection section of protection supply is provided to transformer. It has same concept as overvoltage it also has comparator which compare two voltage one form supply and another from the voltage drop across the variable résistance. When voltage drop across the variable resistance is lower than specified value, this signal sends to microcontroller and microcontroller stop the operation of motor.
Over heating Protection
Overheating protection of motor means protect the transformer from overheating of its winding. This overheating in motor is generally caused by overloading of transformer, transformer simply fails to starts properly, a failure to start of transformer may cause by faulty start in winding in motor. For sensing the heat LM 35 sensor is used for this purpose. This sensor is connected to comparator inputs. With the help of sensor which sense the temperature of winding & its temperature exceeds to some particular level then comparator sends this signal to controller.
Conclusion
The reliability of operation of distribution networks can be increased by using wireless monitoring systems for transformers – not only for power transformers but also for distribution transformers. At present, operators do not have either much measured data or advanced information on transformer substations for maintenance and control. This paper describes an advanced remote monitoring system for distribution transformers which utilizes the existing communication network, has low investment and operation costs and is easy to install and use.