Many people ask me, I build a set of photovoltaic power generation system, off-grid type, how to choose the right inverter? Brand is of course important, well-known companies can be found on the Internet, and the same power brand is much more expensive than the ordinary brand in price. The principle is the same whether it is a famous brand or any other brand. In addition to the brand, origin, principle, materials, we choose the right, cost-effective inverter, what to see?

As a solar inverter expert who has done technical development and product application for many years, I have sorted out some experiences for you today, hoping to be helpful to friends.

First, several basic technical indicators to meet:

1, inverter efficiency: minimum ≥90%

2, waveform distortion: <5.0%

3, overload protection: greater than 110% rated current for 1 minute; Greater than 150% rated current 20S; Greater than 180% rated current for 5 seconds; Greater than 200% rated current 0S.

4, to have a communication function: such as RS485 communication

5, the use of the environment is generally: temperature: -10℃~40℃, humidity: <95% no condensation.

Second, reliability and performance should meet:

1, unique dynamic current loop control technology to ensure the reliable operation of the inverter.

2, strong load adaptability, including capacitive, inductive, mixed load.

3, overload capacity and strong impact resistance.

4, with input over, under voltage, output over, under voltage, over temperature, overload and other perfect protection functions.

5, the inverter front panel is best to use LED display mode, can display battery voltage, output current, output power and other parameters. 

Overall requirements: stable performance, one-click start, safe and reliable control to ensure long service life.

Third, inverter power selection:

If we want to choose the inverter, we must understand the impact capacity of the electric at the start of the moment - the impact is only reflected in the inductive or capacitive negative electricity.

The inverter can instantly output 2 times the nominal power, and the capacitive or inductive load starts instantaneously to 3 to 7 times the peak power. For example: 1000W air conditioning, peak 7000W, inverter 2 times the peak, 7000 divided by 2 is equal to 3500W, that is, to use 1000W power air conditioning, to be equipped with more than 3500W power inverter to start.

This is too complicated to say, the following is our commonly used electrical appliances to list the inverter power to be matched:

1, for pure resistive household electricity such as electric heating wire, light bulb, sun lamp, divide its power by 0.9.

2, the TV, taking liquid crystal as an example, as long as the power of the TV is 2 times larger than the inverter can be.

3, computer, select the LCD TV point plus 90W power (computer host power);

4, air conditioning, non-frequency according to 7 times the peak value, frequency according to 4 times the peak value.

5, for small power electrical in the family, can be ignored.

Common household reasonable battery inverter configuration:

To summarize:

1, home Internet, TV computer, lighting, please match more than 500W inverter plus 100AH battery, use time, 4 hours.

2, freezer, please match more than 1500W inverter plus 150AH battery. Use time is 8 hours.

3, fan, lighting, with 300W inverter plus 36AH battery, use time of 2 hours.
For the home solar system,We suggest with 10pieces 550W solar panel, 1piece 5000w off-grid solar inverter, 5KWH lithium battery