Microinverters represent the concept of component-level control


The ultra-high prosperity of the photovoltaic industry has been repeatedly proven in terms of performance. The photovoltaic inverter sector, which has recently been in a period of adjustment, has been activated again. Let's take a closer look at the future fundamentals of this field.

Microinverters represent the concept of component-level control

The inverter is the heart of the photovoltaic power generation system. It not only plays an important role in converting DC power generated by solar photovoltaics into AC power, but also integrates the power into the grid or uses it for household appliances after completing maximum power point tracking. As the interface between distributed power sources and the power grid, the performance of the inverter will directly affect the power generation efficiency and operational stability of the photovoltaic power generation system.

Inverters are mainly divided into centralized inverters, string inverters and micro inverters. In terms of working principle, a centralized inverter connects a large number of parallel photovoltaic strings to the DC input end of the same centralized inverter. After completing maximum power point tracking, they are then unified and connected to the grid. The string inverter tracks the maximum power of several strings of photovoltaic modules individually, and is integrated into the AC grid after passing through the inverter unit. For micro-inverters, each inverter only corresponds to a small number of photovoltaic modules, enabling individual maximum power point tracking for each photovoltaic module, and is individually integrated into the AC grid after inversion conversion.

Microinverters have higher operating efficiency and better safety and are mainly used in household power generation scenarios.

As a component-level power electronic device, micro-inverters can finely adjust and monitor the output power of each photovoltaic module, and can improve the overall operating efficiency of the photovoltaic system when encountering partial shadow occlusion and individual component performance failures. . At the same time, compared with the 1000V DC high voltage at the input end of centralized and string inverters, the maximum input voltage of micro is only 60V, which greatly reduces the safety hazards of the power station and is simpler to install and debug. However, compared with centralized inverters and string inverters, the price per watt of microinverters is higher, and the current application scenarios are mainly household photovoltaic power plants.

Equipped with DC shutdown function for better safety

Photovoltaic DC safety has become a consensus among distributed photovoltaic power stations, and the establishment of safety standards is beneficial to component-level power electronic equipment. Europe and the United States have clear standards for photovoltaic safety shutdown and voltage and are enforced under regulations. In addition, Thailand, Australia, Mexico and China have formulated corresponding policies and safety standards for the safety of distributed photovoltaics.

The main advantages of microinversion

Microinversion can minimize the impact of obstructions and stabilize system output.

Microinverters have a longer life cycle and save secondary installation costs.

Component-level monitoring improves operation and maintenance efficiency and saves fault repair costs.

Based on high conversion efficiency and low operation and maintenance costs, the LCOE (watt-hour cost of electricity) of micro-inverters can be reduced by at least 10%.

Microinverters have the advantage of naturally having no DC high voltage. Because distributed photovoltaic power generation systems are close to users, they have higher requirements for safety, power generation efficiency, and reliability. When the microinverter is running, the output DC voltage is generally 20-50V, which fundamentally solves the risk of fire caused by DC arcing. And through component-level rapid shutdown, the connection between components can be quickly cut off, reducing the risk of electric shock to workers. Microinverters can integrate inversion, monitoring, power optimization, and shutdown functions and are the only solution to cut off the risk of DC high voltage during operation.