In the off-grid PV system, the PV panel input cell or the battery output is direct current, while the general load needs alternating current. So in the PV system, you need an inverter. Off-grid inverters are divided into many types, let's take a look at which types and their respective characteristics.
01- Corrected wave and pure sine waves
Corrected wave: PWM pulse width modulation is used to generate corrected wave output. Due to harmonic distortion of about 20%, inductive load such as air conditioning can not be brought, but resistive load such as electric lamp can be brought.
Pure sine wave: Pure sine wave inverter adopts an isolation coupling circuit design, which is more complex and costs more. It can connect any common electrical equipment (including TV sets, LIQUID crystal displays, especially inductive loads such as refrigerators) without interference.
Fangpusun Xtalent series inverters are pure sine wave inverters, which can withstand certain overload in a certain time range and can be well adapted to perceptual load.
02- Power frequency isolation and high-frequency isolation
The input end and output end of pure sine wave off-grid inverter have electrical isolation, which can be divided into high frequency isolation and power frequency isolation according to the electrical structure.
High-frequency isolation transformer: At the dc booster, the solution is the first high-frequency alternating current, direct current inverter by high-frequency transformer booster, then rectifier for direct current, then inverter for ac power frequency, high-frequency inverter USES is small volume, lightweight high-frequency magnetic core material, can reduce the weight of the inverter, reduce the volume of the inverter, improve the efficiency of the inverter, But the circuits are complicated.
Power frequency isolation transformer: on the AC end of the end, the inverter circuit is simple, has strong impact resistance, but the volume is large, the weight is heavy.
A lot of people always dislike Fangpusun inverter weight, the reason is this, the use of power frequency isolation transformer, in fact, the cost of power frequency isolation transformer is also higher.
In terms of cost, the Corrected wave inverter is the most economical and the power frequency inverter is the highest. In terms of carrying capacity, power frequency inverter has the strongest capacity. Therefore, when choosing the inverter, it depends on the occasion of use. If it is only a simple lighting application, it is recommended to choose the modified wave inverter, which can save the initial cost. If there is inductive load of air conditioner, washing machine, water pump and other motors, it is recommended to use power frequency inverter, with strong load capacity;