Functions Of Solar Inverters
Inverters not only have DC-AC conversion capabilities, but also the ability to maximize the performance of solar cells and system fault protection functions. These can be summarized as automatic operation and shutdown functions, maximum power point tracking (MPPT) functions, anti-isolation operation functions (for grid-connected systems), automatic voltage regulation functions (for grid-connected systems), DC detection functions (for grid-connected systems), and DC grounding detection functions (for grid-connected systems). Here, we briefly introduce the automatic operation and shutdown functions and the MPPT function.
Automatic Operation and Shutdown Function: After sunrise, the intensity of solar radiation gradually increases, and the output of the solar cells also increases accordingly. When the output power required for the inverter's operation is reached, the inverter automatically starts operating. Once in operation, the inverter continuously monitors the output of the solar cell modules. As long as the output power of the solar cell modules exceeds the output power required for the inverter's operation, the inverter continues to operate until sunset, even on cloudy or rainy days. When the output of the solar cell module decreases and the inverter output approaches zero, the inverter enters standby mode.
Maximum Power Point Tracking (MPPT) Function: The output of the solar cell module varies with the intensity of solar radiation and the temperature of the solar cell module itself (chip temperature). Furthermore, because the voltage of a solar cell module decreases as current increases, there exists an optimal operating point to obtain maximum power. Since solar radiation intensity varies, the optimal operating point also changes. To keep the operating point of the solar cell module at its maximum power point, and for the system to consistently obtain maximum power output from the solar cell module, this control is called maximum power point tracking (MPPT). The most significant feature of inverters used in solar power systems is the inclusion of this MPPT function.
