Efficiency of a solar charging system depends on the weather conditions. Usually the solar panel gets four to five hours of bright sunlight in a day. If the weather is cloudy or rainy, it affects the charging process and the battery does not attain full charge. This proposed hybrid solar charger can solve the problem as it can charge the battery using both solar power as well as AC mains supply. When output from the solar panel s above 12 volts, the battery charges using the solar power. When the output drops below 12 volts, the battery charges through AC mains supply.
The objective of this project is to develop a low cost, compact and high reliable device for the hybrid solar charger. The project design involves a 10W solar panel, operational amplifier , transistor BC547, 12V single change over relay , step-down transformer and a few other components. In bright sunlight, the 12V, 10W solar panel provides up to 17 volts DC with 0.6-ampere current, When output from the solar panel is 12 volts or more the battery is charged by solar supply through enegises relay and this charging status is indicated by a LED ON. When output from the solar panel drops below 12 volts, output of the comparator turns low and the relay de-energizes. Now the battery gets charging current from the transformer-based mains power supply through the normally- closed (N/C) contact of the relay. The operational amplifiers as comparator and zener diode used which comprises the solar voltage for chargable voltage limit 12v. There are a rectifying diode and smoothing capacitor provides charging current from mains while solar power goes below 12v. Thus a battery is kept in continuous charging even if low solar light using this hybrid solar charger.
The proposed on-line uninterruptible power supply (UPS) offers AC voltage regulation on continuity basis which incorporates with the controllable battery charger. The charge control technique used for battery is constant current charging technique. The Constant Current is achieved by limiting the duty cycle of charger (or step-down chopper). Based upon the proposed constant current charging technique, a digital charger is designed and is control through AVR / PIC microcontroller software. In proposed scheme, protection of battery over charge and battery under discharge is available with relay trip through microcontroller by monitoring voltages on continues basis. The backup of battery takes place the load without spikes or delay when the mains power gets fails or interrupted. Experimental results using microcontroller controlled battery charger cum rectifier is presented to shows the effectiveness of the proposed design.
Now a day’s all the Industries are being upgraded to Industry in Wireless Monitoring and Controlling of all the electrical appliances. This project proposes an Iot system controlling the speed of the AC Induction Motor using an ESP8266 WiFi Module and ATmega328 Microcontroller. The web page application as operating system, which operates on wi-fi enable smart phone and acts as a controller, wherein Smart Phone acts as a transmitter while ESP8266 (WiFi Module) acts as the receiver.
The project consists an Arduino series of microcontroller interfaced to an ESP8266 WI-FI module and TRIAC driver circuit. The ESP8266 is configured to access point mode acts as wi-fi server any wi-fi enable device like smart phone/pc can communicate to its over TCP/IP protocol. Hence, a TCP/IP web page/application having GUI button panel is used, it can be connect only after enable TCP/IP - ID and Password entered in any remote smart phone. Then, using GUI button commands like Increase, decrease, stop is transmitted, the data sent from the Smart phone is received by the wi-fi module interfaced to the microcontroller, which will send triggering signal to the Gate pin of TRIAC through optical isolator. So the Voltage to load connected in series with TRIAC is controlled based on received signal. So speed control of AC motor is achieved.
The motor is also protected against Over-under voltage and current with continuous monitor it using a voltage and current sensor, which is also connected in series of the supply line, it measures current and voltages of motor by ADC(analog to digital) circuit of microcontroller. The zero cross of mains AC supply is also detected using op-amp circuit. In case of abnormal voltage and current condition the motor is stopped automatically and it display alert on LCD also on remote phone. The speed controlling data such as RPM, Voltage, Current and firing angle are also displayed on local LCD. A lamp load shall be use in place of a motor whose varying intensity demonstrates the varying power to the motor for speed control.
The main objective of this project is To control electrical load over the internet from anywhere in the world with a status update on password protected dedicated website with all the hardware housed in a supplied compact enclosure for plug and play the automation system.
The proposed project is designed to control any load through the Internet network over cloud remotely on the basic principle of the Internet of things (IOT). For this real-time scenario here use webpage with user configurable front end to control and monitor the load. A Wi-Fi Module (ESP8266) is configured with any nearby wireless modem to access internet. The received internet commands are fed to the Wi-Fi module. The program within the Wi-Fi Module execute the received commands based on which the load gets activated through a relay driver ULN2003 and Opto-coupler interfaced to Wi-Fi Module. The status of the load is also be displayed on the webpage. The power supply consists of 5V and 3.3V voltage regulator for a Wi-Fi module.
In the proposed concept the program code is written within the Wi-Fi module, hence No need of a microcontroller to drive the load. Thus the remote electrical load can be controlled by a standalone wi-fi module. This makes the system very user friendly, compact and less power consume compare to any other automated control system for electrical load.
This project can be further enhanced by interfacing a microcontroller and suaitable driver circuit for controlling more heavy electrical load.
The project is designed to compensate of all three conditions of power factor ie. linear, lagging and leading choosing appropriate load. Power factor is defined as the ratio of real power to apparent power.
This is applicable to reduce the power loss in industries by power factor compensation through a number of shunt capacitors. This results in reduction in amount of electrical bill for industries and commercial establishments.
Power factor is defined as the ratio of real power to apparent power. This definition is often mathematically represented as KW/KVA, where the numerator is the active (real) power and the denominator is the (active + reactive) or apparent power. Reactive power is the non working power generated by the magnetic and inductive loads, to generate magnetic flux. The increase in reactive power increases the apparent power, so the power factor also decreases. Having low power factor, the industry needs more energy to meet its demand, so the efficiency decreases.
In this proposed system the time lag between the zero voltage pulse and zero current pulse duly generated by suitable operational amplifier circuits in comparator mode are fed to two interrupt pins of the microcontroller. Microcontroller displays the power loss due to the inductive load on the LCD. The program takes over to actuate appropriate number of relays at its output to bring shunt capacitors into the load circuit to get zero power loss. The 8 bit microcontroller used in the project belongs to AVR family.
Further the project is enhanced by including a wireless monitor as well as control of this system. Here using a Bluetooth and android operate phone is communicated with the system over wireless serial communication to microcontroller interfaced Bluetooth module. The status of PF and Load parameters can be viewed on phone, also through GUI android application run on the phone one can switching the relay for appropriate compensate the shunt capacitor remotely.