Introduces a new type of high efficient and stable solar energy inverter

The output end of the early solar energy inverter system generally installed isolation transformer, to realize voltage adjustment and electrical isolation, to ensure safe and reliable operation of the system. However, isolation transformer of large volume, high cost, high loss, affect the system efficiency. If the use of high-frequency transformer to achieve the electrical isolation of PV and grid, which can reduce the system volume, quality and cost, but will not significantly improve the efficiency of the system. Therefore, non isolated grid connected photovoltaic inverter system has become a hot research topic. It has the advantages of high efficiency, small size, light weight, low cost and so on. But the elimination of transformers build electrical connection between PV and grid, leakage current could be increased substantially, conducting radiated interference, increase the net current harmonics and loss, even to endanger the equipment and personnel. Therefore, the common mode current elimination has become an obstacle which must be overcomed for the popularization of non isolated grid connected solar inverter.

In view of the above problems, a new type of non isolated single phase solar inverter is studied. This topology not only solves the problem of leakage current effectively, but also has the advantages of low power consumption, high efficiency, strong stability and so on.

For a solar panel inverter, in order to achieve high efficiency and high stability, must meet the following requirements:

(1) In order to improve the stability of the system, the inverter must avoid the shoot-through problem;

(2) To keep the output current waveform from distortion, resulting in not the pipe is damaged, should avoid a dead time;

(3) Common mode leakage current is smaller;

(4) In the guarantee of the system security situation, try to use the good performance MOS tube to improve the efficiency of the system.