Functions of photovoltaic inverter
The inverter not only has the DC/AC conversion function, but also has the function of maximizing the performance of solar cells and system fault protection. To sum up, it has automatic operation and shutdown function, maximum power tracking control function, independent operation prevention function (for grid connected system), automatic voltage adjustment function (for grid connected system), DC detection function (for grid connected system), and DC grounding detection function (for grid connected system).
1. Automatic operation and shutdown function
After sunrise in the morning, the solar radiation intensity gradually increases, and the output of the solar cell also increases. When the output power required by the inverter is reached, the inverter automatically starts to operate. After entering into operation, the inverter will monitor the output of the solar cell module at all times. As long as the output power of the solar cell module is greater than the output power required by the inverter, the inverter will continue to operate; The inverter can operate even in rainy days until sunset. When the output of the solar cell module decreases and the output of the inverter approaches zero, the inverter will form a standby state.
2. Maximum power tracking control function
The output of the solar cell module varies with the solar radiation intensity and the temperature of the solar cell module itself (chip temperature). In addition, because the solar cell module has the characteristics that the voltage decreases with the increase of current, there is an optimal working point that can obtain the maximum power. The solar radiation intensity is changing, and obviously the optimal working point is also changing. With respect to these changes, the operating point of the solar cell module is always at the maximum power point, and the system always obtains the maximum power output from the solar cell module. This control is called maximum power tracking control. The biggest feature of the inverter used in the solar power generation system is that it includes the function of maximum power point tracking (MPPT).
