Efficiency Of Solar Inverters

The efficiency of solar inverters refers to the growing market for solar inverters (photoelectric inverters) due to the demand for renewable energy. These inverters require extremely high efficiency and reliability. The power circuits used in these inverters are investigated, and the best choice of switching and rectifier devices is recommended. The general structure of the photoelectric inverter is shown in Figure 1, there are three different inverters to choose from. The sun shines on Solar modules connected in series, each containing a series of Solar Cell units. The direct current (DC) voltage generated by the solar module is in the order of several hundred volts, depending on the lighting conditions of the module array, the temperature of the battery, and the number of series modules.
The primary function of this type of inverter is to convert the input DC voltage to a stable value. This function is achieved through a boost converter and requires a boost switch and a boost diode. In the first configuration, the booster stage is followed by an isolated full-bridge converter. The role of the full bridge transformer is to provide isolation. A second full-bridge converter on the output is used to convert the DC to AC (AC) voltage from the first-stage full-bridge converter. The output is filtered before being connected to the AC grid network via additional double-contact relay switches to provide safe isolation in the event of a failure and isolation from the supply grid at night. The second structure is a non-isolation scheme. The AC AC voltage is directly generated by the DC voltage output of the boost stage. The third structure utilizes an innovative topology of power switches and power diodes to integrate the functions of the boost and AC generation parts in a dedicated topology. Although the conversion efficiency of solar panels is very low, it is important to keep the efficiency of the inverter as close to 100% as possible. In Germany, a 3kW series module installed on a south-facing roof is expected to generate 2550 kWh per year. If the inverter efficiency is increased from 95% to 96%, an additional 25kWh of electricity can be generated per year. The cost of using additional solar modules to generate this 25kWh is comparable to adding an inverter. Since increasing efficiency from 95% to 96% will not double the cost of the inverter, investing in more efficient inverters is an inevitable choice. Improving inverter efficiency in the most cost-effective way is a key design criterion for emerging designs. As for the reliability and cost of the inverter are the other two design criteria. Higher efficiency can reduce temperature fluctuations over the load cycle and thus improve reliability, so these criteria are actually related. The use of modules also improves reliability.