Working principle of photovoltaic inverter
A photovoltaic inverter converts direct current (DC) to alternating current (AC) through three main stages: a DC-DC converter, an intermediate capacitor, and an AC-AC converter. First, the DC-DC converter converts the DC power generated by the solar panels into the DC power required by the intermediate capacitor. Then, the intermediate capacitor stores the DC power and smooths the output waveform. Finally, the AC-AC converter converts the DC power output from the intermediate capacitor back into AC power and connects the power to the grid or load via an output transformer.
Protection functions of photovoltaic inverters
Photovoltaic inverters typically have multiple protection functions, such as overvoltage protection, undervoltage protection, and overtemperature protection, to protect both the solar panels and the inverter itself. The following are some common protection functions found in photovoltaic inverters:
Overvoltage protection: When the output voltage of the photovoltaic panel exceeds the maximum voltage designed for the inverter, the inverter will automatically disconnect the circuit to avoid circuit overload and damage.
Undervoltage protection: When the output voltage of the photovoltaic panel is lower than the operating voltage range of the inverter, the inverter will automatically cut off the circuit to ensure system safety and panel protection.
Temperature protection: Photovoltaic inverters need to operate within a certain temperature range. When the temperature of electronic components exceeds the acceptable range, the inverter will automatically reduce the operating current or reduce the output power to reduce the temperature of the components and protect the system.
Short circuit protection: When a short circuit occurs in the output circuit of the photovoltaic panel, the inverter will immediately and automatically disconnect the circuit to protect the system and prevent excessive short circuit current from causing safety accidents.
Overload protection: When the system load is too high or a temporary current spike occurs, the photovoltaic inverter will automatically limit the output power to avoid circuit overload and damage.
Grounding protection: In the event of poor electrical grounding or failure of grounding equipment, the inverter will automatically disconnect the circuit to protect operational safety.
Line protection: When the system circuit is abnormal or faulty, the photovoltaic inverter will immediately and automatically cut off the circuit to protect the system and the inverter.
With continuous technological upgrades, modern photovoltaic inverters have higher conversion efficiency, lower power consumption, wider compatibility, and richer functions, making them an indispensable and important component of solar photovoltaic systems.
