Advantages of Three-Phase Grid-Connected Photovoltaic Inverters
1. From the perspective of usage
Three-phase electricity has a relatively high voltage and can drive high-power electrical appliances. For example, three-phase electricity can drive squirrel-cage induction motors. This type of motor has a simple structure, is convenient for maintenance and manufacturing, and is durable, having important applications in industry. Therefore, industrial electricity is generally three-phase electricity. Secondly, the use of three-phase electricity will offer more voltage options because three-phase electricity can be connected to single-phase electricity, while single-phase electricity cannot be connected to three-phase electricity.
2. From the perspective of safety
Three-phase electricity can provide a relatively good voltage level and is relatively safe. Assuming the voltage is 380V for three-phase electricity, and for single-phase electricity, it is also 380V with the neutral line being 0V. However, if it is three-phase electricity, the voltage between two lines is 220V, and there are advantages in terms of voltage level reduction, insulation, wire diameter, and a series of safety issues.
3. From the perspective of physics
The instantaneous power curve of single-phase electricity fluctuates and is unstable. The instantaneous power of a three-phase motor is a straight line, equivalent to the average power, and is relatively stable. Moreover, because the three phases of three-phase electricity are 120 degrees out of phase with each other compared to single-phase electricity, four wires can transmit three times the power of single-phase electricity.
4. From the perspective of economy
For enterprises, the higher the voltage, the cheaper the electricity bill. For a country, if it is single-phase power generation, building the same transmission towers and digging the same cable trenches across the country will cost the same as three-phase power transmission. However, the transmission efficiency of three-phase power is very high. Under the same cost, the transmission capacity of three-phase power is stronger than that of single-phase power.
Three-phase grid-connected power generation is a three-phase power grid connected by an inverter, while single-phase grid-connected power generation is single-phase grid-connected power generation. The three-phase grid-connected power system is widely used. The inverter has a high power density, the output power quality is good, the three-phase balance has little impact on the power grid, the load on the power grid is light, and the power utilization rate is high. It will be increasingly applied to power generation systems.