SHARAD INSTITUTE OF TECHNOLOGY COLLEGE OF ENGINEERING,

YADRAVA

PRESENTATION ON

“MONITORING OF SUBSTATIONS USING MICROCONTROLLER ”

PRESENTED BY Mr. Mohsin I. Sutar

Mr. V. V Khandare

UNDER THE GUIDANCE OF

DEPARTMENT OF ELECTRONICS AND TELE-COMMUNICATION ENGG.

INTRODUCTION

Main station transformers convert the generator's voltage to extremely high voltages (155kV to 765 kV).

Then, the voltage level is reduced using transformers and power is transferred to customers through electric power distribution systems (transformer)(typically to less than 10kV).

Distributed transformers are prone to damages due to the raise in oil temperature when there is an overload or huge current flows through the internal winding of the transformer.

We are going to designed a system based on microcontroller (AVR) that monitors and controls the voltage, current and oil temperature of a distribution transformer present in a substation. The monitored output will be displayed on a LCD at the main station that is at a remote place, through ZIGBEE communication.

OBJECTIVE

The purpose of this project is to monitor the remote electrical parameters like voltage, current and temperature of a distribution transformer of substation and send these real time values over ZIGBEE communication to the main station.

ABSTRACT OF THE PROJECT

A system based on AVR micro controller that is used for monitoring the voltage, current and temperature of a distribution transformer in a substation and to protect the system from the rise in mentioned parameters.

Providing the protection to the distribution transformer can be accomplished by shutting down the entire unit with the aid of the ZIGBEE Communication.

Furthermore it is capable of recognizing the break downs caused due to overload, high temperature and over voltage.

The design generally consists of two units, one in the substation unit, called as transmitter and display unit, and another in the Main station called as controlling unit.

The transmitter and the display units in the substation is where the voltage, current and temperature are monitored continuously by AVR microcontroller and is displayed through the display unit.

An ZIGBEE transmitter is used for transmitting the signals that are obtained. The controlling unit in the main station by means of a AVR MC and a ZIGBEE receiver receives the signals that are transmitted by the Transmitter unit and reacts in accordance to the received signal.

The ultimate objective is to monitor the electrical parameters continuously and hence to guard the burning of distribution transformer or power transformer due to the constraints such as overload, over temperature and input high voltage. If any of these values increases beyond the limit then the entire unit is shut down by the designed controlling unit

PROJECT OVERVIEW Monitoring of substations are essential task for supplying

healthy power to the consumers , there are transmission or distribution substations those supply electrical power to various loads. Remote monitoring make these substations to be operated through wireless communication technologies like ZIGBEE,..etc

Substations consist of various equipment like transformers, circuit breakers, relays etc,…. And these equipments ought to be operated in such that the loads must be delivered safely with specified parameters. These parameters include voltage, current, temperature. The following ZIGBEE based project deal with substation monitoring aspects

WORKING PRINCIPLE The substation contains ZIGBEE transmitter and AVR

microcontroller. The main station consists of AVR Microcontroller, ZIGBEE receiver and LCD display. The parameters (current, voltage, oil temperature) of the substation is continuously acquired by the AVR Microcontroller and transmits through the ZIGBEE transmitter to the main station. The ZIGBEE receiver in the main station receives the signal and compares it to the reference rated measurements . If the received information is below the reference rated measurements it does not shows any variation or if it is above the reference rated measurements then that increased range is viewed by LCD and indicated using LED and further damage can be avoided by shutting down the substation using relay from the main station.

BLOCK DIAGRAM

DESIGN PROCEDURES

Define the interfacing parameters for LCD and Data Registers.

Assign a value for the circuit elements such as Relay, LED.

Initialize the input and output ports of the microcontroller. The displaying function is called and the parameter values are displayed.

The captured values are transmitted by calling ZIGBEE transmitter function

EQUIPMENTS USED ZIGBEE:

ZIGBEE is based on an IEEE 802.15.4 personal area network. The technology defined by the ZIGBEE specification is intended to be simpler and less expensive than other WPANs, such as Bluetooth. ZIGBEE is targeted at Radio Frequency (RF) applications that require a low data rate, long battery life, and secure networking. ZIGBEE has a defined rate of 250 kbps. In substation unit the power is continuously monitored and it is transmitted through ZIGBEE transmitter and the transmitted signal is received by ZIGBEE receiver.

Fig- Zigbee module

Performance

RF Data Rate 250 kbps

Indoor/Urban Range

133 ft (40 m)

Outdoor/RF Line-of-Sight Range

400 ft (120 m)

Transmit Power 1.25 mW (+1 dBm) / 2 mW (+3 dBm) boost mode

Receiver Sensitivity (1% PER)

-97 dBm (-98 dBm boost mode)

AVR MICROCONTROLLER• Features :- High-performance, Low-power, 8-bit Microcontroller Advanced RISC Architecture 118 Powerful Instructions – Most Single-clock Cycle Execution – 32 × 8 General Purpose Working Registers Fully Static Operation Up to 8MIPS Throughput at 8MHz – On-chip 2-cycle

Multiplier

AVR MICROCONTROLLER PINOUT

RELAY Number of poles 1 pole Contact resistance 100 mΩ max. Operate (set) time: 15 ms max. Release (reset) time: 5 ms max. Max. operating frequency Electrical:1,800

operation/hr at rated load Dielectric strength: 5,000 VAC, 1 min

between coil and contacts Endurance (Mechanical) 20,000,000

operations (at 18,000 operations/hr) Ambient humidity 5% to 85% Weight Approx. 12 g

LCD DISPLAY

• Pin No Function Name

1 Ground (0V) Ground

2 Supply voltage; 5V (4.7V – 5.3V) Vcc

3 Contrast adjustment; through a variable resistor

VEE

4 Selects command register when low; and data register when high

Register Select

5 Low to write to the register; High to read from the register

Read/Write

6 Sends data to data pins when a high to low pulse is given

Enable

7 8-Bit data pins DB0

8 DB1

9 DB2

10 DB3

11 DB4

12 DB5

13 DB6

14 DB7

15 Backlight VCC (5V) Led+

16 Backlight Ground (0V) Led+

ADVANTAGES:- Remote monitoring to avoid further power

loss and time. Whole system can be shut down for quick

repairs and re-installations. Low maintenance . Fair efficiency. High accuracy.

DISADVANTAGES

Bulky circuit construction.Costly.Less operating area.

FUTURE SCOPE & PLAN This project can be implemented by using GPRS

technology so that captured data can be send anywhere in the world.

We can turn it to a “Smart Energy Meter” by which electricity parameters along with cost calculation can be monitored by the user by GSM or GPRS so they can minimize their electricity uses to optimum level.

CONCLUSION

In this project we have presented a design of a system based on AVR microcontroller that is used to monitor and control the voltage, current and temperature of a distribution transformer by shutting it down.This claims that the proposed design of the system makes the distribution transformer more robust against some key power quality issues which makes the voltage, current or temperature to peak. Hence the distribution is made more secure, reliable and efficient by means of the proposed system.

REFERENCE

An efficient monitoring of substations using microcontroller based monitoring system, IEEE Paper proposed by Mr. V. Thiyagrajan on July 2010.

Wikipedia