voltage & frequency monitoring through lcd

VOLTAGE & FREQUENCY VOLTAGE & FREQUENCY MONITORING THROUGH LCDMONITORING THROUGH LCD

Presented By:oK. Hari Kishore 08MP1A0229K. Hari Kishore 08MP1A0229

Under The Guidence of :Under The Guidence of :

V.Chatanya Prasad(M-Tech)V.Chatanya Prasad(M-Tech)

Asst.Prof. EEE DepartmentAsst.Prof. EEE Department

ABSTRACT OF VOLTAGE & ABSTRACT OF VOLTAGE & FREQUENCY MONITORING FREQUENCY MONITORING

The abstract of this project is to monitor the voltage and frequency in single phase environment and display it on display module.

This is achieved with the sequential operation of the micro controller AT mega8 and potential transformers.

We step down voltages with the help of instrument transformers so that the ADC within the micro controller can sample them.

For frequency measurement we are using an external circuit which produces a continuous sine wave and we are feeding this output to MC-ADC pin then it will calculate appropriate frequency.

Embedded System

Microprocessors

Microcontrollers

INTRODUCTIONINTRODUCTION

BASIC LAYOUT OF BASIC LAYOUT OF MICROCONTROLLERMICROCONTROLLER

BLOCK DIAGRAM OF VOLTAGE & BLOCK DIAGRAM OF VOLTAGE & FREQUENCY MONITORINGFREQUENCY MONITORING

The ATmega8 is a low-power CMOS 8-bit microcontroller based on the AVR RISC architecture

This is high-performance, Low-power AVR 8-bit Microcontroller 8K Bytes of In-System Self-programmable Flash program

memory – 512 Bytes EEPROM 1K Byte Internal SRAM Two 8-bit Timer/Counters with Separate Prescaler, one

Compare Mode Operating Voltages 2.7 - 5.5V (ATmega8L) – 4.5 - 5.5V

(ATmega8) Power Consumption at 4 MHz, 3V, 25ºC

Active: 3.6 mA Idle Mode: 1.0 mA Power-down Mode: 0.5 µA

AT MEGAAT MEGA88 MICROCONTROLLER MICROCONTROLLER

PIN DIAGRAM OF AT MEGAPIN DIAGRAM OF AT MEGA88

VCC Digital supply voltage.

GND Ground.

Port B (PB7..PB0) 8-bit bi-directional I/O port with internal pull-up

resistors Pins are tri-stated when a reset condition becomes

active, even if the clock is not running. PB6 can be used as input to the inverting Oscillator

amplifier PB7 can be used as output from the inverting

Oscillator amplifier.

PIN DESCRIPTION OF AT MEGAPIN DESCRIPTION OF AT MEGA88

Port C (PC5..PC0) It is a 6-bit bi-directional I/O port with internal pull-

up resistors The Port C pins are tri-stated when a reset condition

becomes active, even if the clock is not running. Port D (PD7..PD0)

It is an 8-bit bi-directional I/O port with internal pull-up resistors

pins are tri-stated when a reset condition becomes active, even if the clock is not running.

RESET A low level on this pin for longer than the minimum

pulse length will generate a reset, even if the clock is not running.

PIN DESCRIPTION OF AT MEGAPIN DESCRIPTION OF AT MEGA88

The ATmega8 features a 10-bit successive approximation ADC.

The ADC is connected to an 8-channel Analog Multiplexer which allows eight single-ended voltage inputs constructed from the pins of Port C.

The ADC contains a Sample and Hold circuit which ensures that the input voltage to the ADC is held at a constant level during conversion.

The ADC has a separate analog supply voltage pin, AVCC which must not differ more than ± 0.3V from VCC

The ADC converts an analog input voltage to a 10-bit digital value through successive approximation.

ANALOG TO DIGITAL CONVERTERANALOG TO DIGITAL CONVERTER

The primary winding of the P.T. is connected across the line carrying the voltage to be measured and the voltage circuit is connected across the secondary winding.

The design of a potential transformer is quite similar to that of a power transformer but the loading of a potential transformer is always small, sometimes only a few Volt-amperes.

The secondary is designed so that a voltage of 9 volts is delivered to the instrument load.

POTENTIAL TRANSFORMERPOTENTIAL TRANSFORMER

Current transformers measure power flow and provide electrical inputs to power transformers and instruments.

A current transformer (CT) is a type of instrument transformer designed to provide a current in its secondary winding proportional to the alternating current flowing in its primary.

The current transformer safely isolates measurement and control circuitry from the high voltages typically present on the circuit being measured.

CURRENT TRANSFORMERCURRENT TRANSFORMER

CONNECTIONS OF CT & PTCONNECTIONS OF CT & PT

INTERFACING OF LCD TO ATMEGAINTERFACING OF LCD TO ATMEGA88

JHD 162A LCD PIN JHD 162A LCD PIN CONFIGURATIONCONFIGURATION

Frequency information can be used in many areas of power system analysis, operation, and control.

The voltage metering is used in wide range of applications not only for measuring but also for controlling.

The project constantly monitors voltage and frequency indicating potential improper polarity and ground wiring.

The RMS voltage and frequency readings are ideal for monitoring modified sine waves such as solid-state generators, inverters and Uninterruptible Power Supply (UPS) products.

APPLICATIONSAPPLICATIONS

Frequency dynamics is one of the most

important measures of an electrical power

system status. To better understand power

system dynamics, an accurately measured

frequency is needed.

CONCLUSIONCONCLUSION