What are the functions of photovoltaic inverters?

As an important component of photovoltaic power generation, the main function of photovoltaic inverters is to convert the direct current generated by photovoltaic modules into alternating current. The inverter not only has the function of direct AC conversion, but also has the function of maximizing the performance of solar cells and system fault protection. The following is a brief introduction to the automatic operation and shutdown functions of photovoltaic inverters, as well as the maximum power tracking control function.

(1) Maximum power tracking control function

The output of solar cell module varies with the radiant intensity of the sun and the temperature of the solar cell module itself (chip temperature). In addition, due to the characteristic that the voltage of solar cell components decreases with the increase of current, there is an optimal operating point for obtaining maximum power. The solar radiant intensity intensity is changing, and obviously the optimal working point is also changing. Compared to these changes, always keep the working point of the solar cell module 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 inverters used in solar power generation systems is that they include the function of Maximum Power Point Tracking (MPPT).

(2) Automatic operation and shutdown functions

After sunrise in the morning, the solar radiant intensity intensity gradually increases, and the output of the solar cell also increases. When the output power required by the inverter is reached, the inverter will automatically start to operate. After entering operation, the inverter constantly monitors the output of the solar cell module. As long as the output power of the solar cell module is greater than the output power required for inverter operation, the inverter will continue to operate; Until sunset, the inverter can operate even on cloudy and rainy days. When the output of the solar cell module decreases and the inverter output approaches 0, the inverter forms a standby state.

In addition to the two functions mentioned above, the photovoltaic inverter also has functions such as anti separate operation (for grid connected systems), automatic voltage adjustment (for grid connected systems), DC detection (for grid connected systems), and DC grounding detection (for grid connected systems). In solar power generation systems, the efficiency of inverters is an important factor determining the capacity of solar cells and battery capacity.