Introduction of Centralized Photovoltaic Inverter

Centralized photovoltaic inverter is a kind of photovoltaic inverter. It has the overall scheme of power frequency integration, rich device selection, perfect heat dissipation design and protection design, rich protection design and redundant backup design, and high reliability. . The advantages and disadvantages of centralized photovoltaic inverters are introduced below.

1. The number of inverters is small, which is easy to manage.

2. The number of inverter components is small and the reliability is high.

3. Less harmonic content, less DC component and high power quality.

4. The inverter has high integration, high power density and low cost.

5. Various protection functions of the inverter are complete, and the safety of the power station is high.

6. With power factor adjustment function and low voltage ride through function, the power grid has good regulation.

1. The DC combiner box has a high failure rate, which affects the entire system.

2. The MPPT voltage range of the centralized inverter is narrow, generally 450-820V, and the component configuration is not flexible. In rainy days and foggy areas, the power generation time is short.

3. The installation and deployment of the inverter machine room is difficult and requires special machine rooms and equipment.

4. The power consumption of the inverter itself and the power consumption of ventilation and heat dissipation in the equipment room make the system maintenance relatively complicated.

5. In the centralized grid-connected inverter system, the square array of components reaches the inverter through two confluences, and the maximum power tracking function (MPPT) of the inverter cannot monitor the operation of each component, so it is impossible to keep each component at The optimal working point, when a component fails or is blocked by shadows, it will affect the power generation efficiency of the entire system.

6. There is no redundancy capability in the centralized grid-connected inverter system, and if a fault occurs, the entire system will stop generating power.

The equipment power of the centralized photovoltaic inverter is between 50KW and 630KW. The power device adopts high-current IGBT. The system topology adopts DC-AC first-class power electronic device to transform the full-bridge inverter, and the power frequency isolation transformer is used. The protection level Generally IP20. Larger volume, indoor vertical installation.