The Function of Photovoltaic Inverter
The solar inverter not only has the function of DC-to-AC conversion but also has the function of maximizing the performance of the solar array and therefore the function of system failure protection. In summary, there are automatic operation and shutdown functions, maximum power tracking control operation, anti-single operation function (for on-grid systems), automatic voltage adjustment function (for on-grid systems), DC detection function (for on-grid systems), DC grounding detection Function (for the on-grid system). Here may be a brief introduction to the automated operation and shutdown functions and therefore the maximum power tracking control operation.
（1） Automatic operation and shutdown function
After sunrise within the morning, the radiation intensity gradually increases, and therefore the output of the solar array also increases. When the output power required by the inverter is reached, the inverter automatically starts to work. After entering the operation, the inverter will always monitor the output of the photovoltaic cell module. As long because the output power of the photovoltaic cell module is bigger than the output power required by the inverter, the inverter will still run; it’ll stop until sunset, albeit it’s cloudy or rainy. The inverter also can be operated. When the output of the photovoltaic cell module becomes smaller and therefore the output of the inverter approaches 0, the inverter enters a standby state.
（2）Maximum power tracking control operation
The output of the photovoltaic cell module varies with the intensity of radiation and therefore the temperature of the photovoltaic cell module itself (chip temperature). additionally, because the photovoltaic cell module has the characteristic that the voltage decreases with the rise of the present, there’s an optimal operating point that will obtain the utmost power. The intensity of radiation is changing, and therefore the best operating point is additionally changing. Relative to those changes, the operating point of the photovoltaic cell module is usually at the utmost point, and therefore the system always obtains the utmost power output from the photovoltaic cell module. this type of control is the maximum power tracking control. the most important feature of the inverter utilized in the solar energy generation system is that it includes the utmost point tracking (MPPT) function.