The selection of solar inverters requires comprehensive consideration of multiple factors. The following are some key points:
Power Matching:
The rated power of the inverter should be slightly greater than the maximum power of the solar panels. For example, if the total power of the solar panels is 5kW, an inverter with a rated power of 5.5kW - 6kW can be selected.
The peak power of the inverter needs to meet the starting requirements of high-power electrical appliances. Generally, the peak power of the inverter should be at least 1.5 - 2 times the sum of the starting powers of these high-power electrical appliances.
Conversion Efficiency:
The conversion efficiency is an important indicator for measuring the performance of the inverter. A high-efficiency inverter can convert more DC power output from the solar panels into AC power, reducing energy loss. Generally, the conversion efficiency of high-quality solar inverters should be between 95% and 98%. For example, with the same solar input, an inverter with a conversion efficiency of 98% can output 3% more electrical energy than one with a conversion efficiency of 95%. Over the long term, this will have a significant impact on power generation revenue.
Input and Output Characteristics:
Input Voltage Range: The output voltage of solar panels will fluctuate with changes in light intensity and temperature. Therefore, the inverter needs to have a wide input voltage range to adapt to the output of solar panels under different working conditions. For example, the input voltage range of common photovoltaic inverters may be between 200V and 500V, which can be compatible with different types and quantities of solar panels connected in series.
Output Waveform: Select an appropriate output waveform according to the requirements of the electrical appliances. For some electrical appliances with high requirements for power quality, such as computers and precision instruments, a sine wave inverter should be used. Its output waveform is close to that of the utility power, which can provide stable and pure AC power and avoid damage to the equipment. For some electrical appliances with low requirements for the waveform, such as lights and electric heaters, a square wave or modified sine wave inverter can also meet the basic needs, but it may generate some noise during use or cause slight interference to some equipment.
Safety Performance:
Overcurrent Protection: When the current in the circuit exceeds the rated current of the inverter, the overcurrent protection device will automatically cut off the circuit to prevent the inverter and other equipment from being damaged due to overcurrent, and even avoid safety accidents such as fires.
Overvoltage Protection: When the input voltage or output voltage exceeds the set value, the overvoltage protection function will be activated to prevent the equipment from being damaged due to excessive voltage.
Leakage Protection: Once a leakage situation in the circuit is detected, the leakage protection device will quickly cut off the power supply to protect the safety of personnel and equipment. This is particularly important for solar inverters installed outdoors or in humid environments.
Communication Function:
Inverters with communication functions can facilitate users to remotely monitor and manage the solar power generation system. Through interfaces such as RS485, CAN, Ethernet, or wireless communication (such as GPRS, Bluetooth, ZigBee, etc.), users can view the operation status, power generation data, fault information, etc. of the inverter in real time on devices such as mobile phones and computers, and can also perform remote parameter setting and control, improving the operation and maintenance efficiency and management level of the system.
