Inverters are widely used in the domestic as well as industrial environments to serve as second line of source in case of power cut form the electricity utility grids. However, due to low capacity of the battery the inverter dies out with the use of heavy load appliances. This project is designed in such a way that it overcomes this limitation by the use of solar energy. Hybrid Inverter with Solar Battery Charging System consists of an inverter powered by a 12V Battery. This inverter generates up to 110V AC with the help of driver circuitry and a heavy load transformer. This battery gets charged from two sources, first being the mains power supply itself. If the mains power supply is available, the relay switches to the connection using mains power supply to supply to the load. This power supply also charges the battery for using it as back up the next time there is power outage. The use of solar panel to charge the battery gives an additional advantage of surplus power in case the power outage of mains is prolonging. Thus this inverter can last for longer duration’s and provide uninterrupted power supply to the user.
Block Diagram
We live in a wired world, where nearly everything in our lives requires a steady supply of electricity to remain in operation. Sometimes extreme weather conditions, car accidents, falling trees, unusually high power demands, or even damage caused by animals can cause severe disruptions in a local or regional electrical grid, leaving our home without electricity for hours or more at a time. So, we use inverter in our houses. Inverters are widely used in the domestic as well as industrial environments to serve as a second line of source.
A solar inverter’s main job is to convert DC power generated from the photovoltaic cell into AC power. Hybrid inverters go a step further and work with batteries to store excess power as well. But this solar inverter system is inefficient in charging the battery during cloudy weather condition. The battery requires more than 1 Ampere current for proper charging and due to low capacity of the battery, when solar power is not available. the battery dies out with the use of heavy load appliances. To solve this problem, we made a “Hybrid Inverter with Solar Battery Charging”.
This project is designed in such a way that it overcomes the limitation by the use of only solar energy. Electricity from the solar panel is generated only during the day, with peak generation around midday. This generation fluctuates with various weather conditions and as there is no generation in the night, it is not possible to constantly supply the demands from the load end. When solar power is not available or insufficient to supply the load demands and if the mains power supply is available, then this “Hybrid Solar Inverter” switches to AC mains power supply for supplying the load.
This power supply then charges the battery for using it as back up for the next time when there is a power outage in the mains. The use of solar panel to charge the battery gives an additional advantage of surplus power in case the power outage of mains is prolonging. Thus this inverter can last for longer duration’s and provides uninterrupted power supply to the user.
An intelligent hybrid inverter or smart grid inverter is a new generation of dedicated U.P.S. (Uninterruptible Power Supply) system which can use both electrical as well as solar energy to charge the system storage battery which can be used to generate electricity in the absence of either or both of energy sources. Usually electricity from solar panels is generated only during the day, with peak production around midday. This electricity is fluctuating and not synchronized with the electric consumption of the household. To overcome this gap between what is produced and what is required during the evening when there is no solar electricity production, it is necessary to store energy for later use and manage energy storage and consumption in an intelligent way.
Working Principle :
Hybrid inverter using solar charger is combination of two circuits
1. Charging circuit.
2. Inverter circuit.
Working of Charging circuit:
In charging circuit, when output from the solar panel is 12 volts, the battery charges using the solar power. When the output of solar panel drops below 12 volts, the battery charges through the AC mains power supply. This changeover is done through the 12 volts SPDT (single pole double throw) relay. In bright sunlight solar panel gives a steady output of 12 volts.Then the zener diode goes in breakdown region and provides 11 volts to the inverting terminal of the comparator . Since its non-inverting input gets a higher voltage at this time, the output of the comparator turns high and the same is indicated by glowing green.then the Transistor conducts and the relay energizes. Thus the battery gets charging current from the solar panel through the normally-open (N/O) and common contacts of relay. A glowing green LED indicates charging of the battery from the solar panel. A capacitor is provided for clean switching of transistor. There is a diode to protect the transistor from back EMF and another diode prevents the discharge of battery current into the circuit. When output from the solar panel drops below 12 volts, output of the comparator turns low and the relay deenergizes. Now the battery gets charging current from the transformer-based power supply through the normally closed (N/C) and common contacts of the relay. This power supply comprises step-down transformer, two rectifying diodes, and smoothing capacitor.
Working of Inverter Circuit:
The inverter circuit is basically a multivibrator. The negative voltage passing through the capacitor C2 turns off the transistor Q1 which causes the capacitor C1 to initiate charging through resistor R and Vcc, as well as through the base emitter of transistor Q2. This causes the transistor Q2 to acquire the momentary ON state.During the process, the capacitor C2 gradually discharges until it's completely empty, and then it starts charging from opposite direction through R2.
Conclusion:
Sun, being source of clean, pollution-free energy and Photovoltaic power production is gaining more significance as a renewable energy source due to its various advantages. The advantages include everlasting production scheme, ease of maintenance, and direct sunbeam to electricity conversion. However the high cost of installations still forms an obstacle for this technology. Moreover the PV panel output power fluctuates as the weather conditions, such as the luminosity of the solar beam, cell temperature etc.
The desired design of the system will produce the desired output of the project. The inverter will supply an AC source from a DC source.
The project described is valuable for the promising potentials it holds within. Ranging from the long run economic benefits to the important environmental advantages. This work will mark an attempt and contribution in the field of renewable energy and can be implemented extensively
.