A solar inverter is a device that converts direct current (DC) produced by solar panels into alternating current (AC) for consumers or injection into the power grid. In a photovoltaic solar system, inverters act as the heart of the system and convert the generated DC electricity into AC. In the following, we will examine the types of solar inverters, including connected to the grid (ongrid) and disconnected or separated from the grid (offgrid). We also explain how solar inverters work.
In general, solar inverters are classified as follows:
Classification of inverters in terms of output waveform
Classification of inverters in terms of connection to the grid
Classification of inverters in terms of panel connections
Review of inverters in terms of output waveform:
Square wave inverters
Modified sine wave inverters
pure sine wave inverter
Square wave inverters
This inverter is the cheapest and at the same time the worst type of inverters. A square wave is an inappropriate and unpleasant wave for most electrical devices. These inverters are usually cheap, powers less than 500 watts and more are used for car cigarette lighters. So these inverters do not work at all for home and industrial use.
Modified sine wave inverters
It can be said that the most economical and common inverter is this type. This type of inverter produces an alternating wave whose shape is between a square wave and a perfect sine wave. In many cases, these types of inverters are also called quasi-sine wave inverters. The advantage of these types of inverters is their low price and overall good performance, and most electrical devices such as lighting devices, radios, many televisions and computers, etc., can be started with these inverters, but some electrical devices, such as most motors, are capable of They do not work with these inverters. So we conclude that this inverter is used for small purposes.
Pure sine wave inverter
As it is clear from the name of this inverter, it produces a complete or pure sine wave to the extent that in some inverters it even produces a better sine wave than city electricity. This inverter is able to run all electrical appliances at its capacity, but the price of this inverter is expensive. So it can be said that this model is the best type of inverter and it can be used for all purposes.
As mentioned, the best type of inverter is the pure sinusoidal type, but because it is expensive, it cannot be used in many small applications. But among the other two inverters, the pseudo-sine type is better than the square one. Because with a pseudo-sine inverter, it is possible to start electrical appliances with motors such as refrigerators, only the power loss of these appliances increases and their life is slightly reduced. But the square wave inverter should not be used for motor devices at all because this type of inverter goes from a positive value to a negative value in a moment and this sudden sign change is very dangerous for motor devices. So, in general, pure sine and pseudo-sine inverter should be used.
Source: https://palmoreco.com/blog/types-of-solar-inverters/