The inverter not only has a direct AC conversion function, but also functions to maximize the performance of the solar cell and system fault protection. It can be summarized as automatic running and stopping function, maximum power tracking control function, anti-individual operation function (for grid-connected system), automatic voltage adjustment function (for grid-connected system), DC detection function (for grid-connected system), DC grounding detection Function (for grid-connected systems). Here is a brief introduction to the automatic operation and shutdown functions and maximum power tracking control functions.
1.Automatic operation and shutdown function
After the morning sunrise, the solar radiation intensity gradually increases, and the output of the solar cell also increases. When the output power required for the operation of the inverter is reached, the inverter automatically starts running. After entering the operation, the inverter monitors 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 for the operation of the inverter, the inverter continues to operate; until sunset stops, even in rainy days. The inverter can also operate. When the output of the solar cell module becomes smaller and the inverter output approaches 0, the inverter forms a standby state.
2.Maximum power tracking control
The output of the solar cell module varies with the intensity of the solar radiation and the temperature of the solar module itself (chip temperature). In addition, since the solar cell module has a characteristic that the voltage decreases as the current increases, there is an optimum operating point at which the maximum power can be obtained. The intensity of solar radiation is changing, and it is clear that the optimal operating point is also changing. Relative to these changes, the operating point of the solar module is always at the maximum power point, and the system always obtains the maximum power output from the solar module. This control is the maximum power tracking control. The most important feature of inverters for solar power systems is the inclusion of maximum power point tracking (MPPT).