What is the role of isolation transformer in solar inverter?

What is isolation transformer?

An isolation transformer is a stationary device designed to separate primary and secondary windings, ensuring physical and electrical isolation between circuits. It transfers electrical energy through magnetic induction, using a magnetic field to induce an electromotive force (EMF) in a secondary circuit while maintaining the original frequency.

What is ‌solar inverter?

‌Solar inverter is a kind of equipment that converts direct current generated by solar panels into alternating current, which is an important part of photovoltaic system. Its main function is to convert the direct current generated by solar panels into alternating current required by household appliances, so that solar power generation can be directly applied to various electrical equipment. ‌

transformer

What is the role of isolation transformer in solar inverter?

Isolation transformers play a crucial role in solar inverters. The main function of the solar inverter is to convert the direct current generated by the solar panels into alternating current for home and business use. The isolation transformer is a special transformer that electrically isolates the input circuit and the output circuit. Its role in the solar inverter is mainly reflected in the following aspects:

Electrical isolation: The isolation transformer transfers energy through the magnetic circuit, enabling electrical isolation between the primary and secondary windings. This isolation helps prevent the formation of current loops, reduces electrical interference and noise and ensures system safety. At the same time, it can also prevent DC components and leakage current from entering the grid, protecting the security of equipment and the grid.

Suppression of harmonics: The inverter may produce higher harmonics in the process of converting direct current to alternating current. The isolation transformer can effectively filter out these harmonics, especially the third harmonics and their multiples, which reduces the pollution to the power grid and improve the power quality.

Increase the short-circuit impedance: When a short-circuit fault occurs on the load side, the impedance in the secondary winding of the isolated transformer can reduce the short-circuit current. This can reduce the impact and potential damage of the short-circuit current on the inverter and improve the stability of the system.

Voltage boost: The transformer in the inverter is mainly used for voltage boost, so that the output voltage of the inverter can match the grid voltage. Thus, it is easy to integrate the electricity generated by the photovoltaic system into the grid.

Matching voltage: Grid voltage standards may be different in different countries. By adding an isolation transformer behind the inverter, the output voltage can be adjusted to suit the grid requirements of different countries.

Improve the adaptability of the power grid: When the voltage fluctuation of the power grid is large or there is a large motor, welding machine and other loads, the isolation transformer can prevent the current mutation and improve the stability of the system.

Suppression of PID effect: In the photovoltaic system, the isolation transformer can also be used to suppress the potential induced attenuation (PID) phenomenon of the photovoltaic module. By increasing the potential of the N pole to the ground, the potential of the negative pole to the ground of the component is indirectly increased to achieve the purpose of suppressing PID.