2What is an Inverter?An inverter is an electrical circuit capable of turning DC power into AC power, while at the same time regulating the voltage, current, and frequency of the signal
3Why do I need an inverter? Most solar panels provide 12V DC powerHousehold devices use 120V AC powerNecessary for a grid tie in system
4What kind of inverter do I want? Inverters come in all different shapes and sizes, for all different purposesInverters vary in output from 50 – 5,000 WSeveral different methods of changing DC power to AC powerSome inverters put out electricity of higher ‘quality’ than others. What does that mean?
5Electrical wave forms Graphs of voltage as a function of time Power that comes from a PV panel or battery is generally 12V DC PowerDifferent types of inverters give outputs with different wave forms12V DC PowerSquare WaveModified Sine WaveTrue Sine Wave
6Different types of inverter output Square wave inverters are basically obsoleteModified sine wave output will power almost everything in your house. However, things like power drills, or battery chargers may not workTrue sine wave output is exactly the same as the power provided by a utility company, and is necessary for a grid inter-tie system
7Methods of inversionRotary inverters use a DC motor to turn an AC Power generator, the provide a true sine wave output, but are inefficient, and have a low surge capacity ratingElectrical inverters use a combination of ‘chopping’ circuits and transformers to change DC power into AC. They are much more widely used and are far more efficient and practical. Less expensive electrical inverters produce a modified sine wave, while more expensive models give a true sine wave.
8How do they work?There are 2 types of electrical inverters, the first takes low voltage high current power from a PV panel or battery and sends it through a ‘chopping’ circuit which changes it to low voltage high current AC power at 60Hz. The power then goes through a series of large transformers which output 120V AC power at 60Hz
9How do they work?The second type of electrical inverter is more complex. Two chopping circuits are employed to make it possible for a much smaller and lighter transformer to be used. The DC power is converted to very high frequency AC power which is easier to transform into high voltage low current power. The power is then rectified back into DC power and sent through a second chopping circuit to turn it into 60Hz 120V AC.
10How are Inverters rated? Continuous output rating: The maximum wattage that the inverter can support long term, includes all everyday appliances, lights and anything else that consumes power.Surge capacity rating: The maximum wattage that cam be supported at any given time. Important when starting devices like refrigerators or water pumps which require more wattage to start then to run.
11Applications of Inverters Inverters are used for many practical purposesSmall inverters can plug into your car cigarette lighterLarge inverters can be used in a solar or wind powered home