Learn How To Choose A Suitable Voltage Optimizer In One Article

Selecting an inappropriate Voltage Optimiser may cause problems such as reduced component power generation, inverter shutdown, and optimizer damage, resulting in direct economic losses. So how to choose a suitable optimizer based on your photovoltaic system is crucial.

01 Determine the needs

Different models of optimizers have different functions and can be freely selected according to the actual situation of the photovoltaic system.

02 Determine the PV Module

When selecting a suitable optimizer, it is necessary to fully consider the parameters of the PV modules and inverters. Among them, the PV modules need to focus on the maximum power, open circuit voltage and short circuit current under STC (Standard Test Conditions). Take the modules of a leading manufacturer as an example:

Based on the parameter comparison under STC conditions, when selecting an optimizer, the optimizer parameters need to meet the following conditions:

Ø The nominal power of the optimizer ≥ the maximum power of the module

Ø The maximum input voltage of the optimizer ≥ the open circuit voltage of the module at the extremely low temperature of the use site

Ø The maximum input current of the optimizer ≥ the short circuit current of the module at the extremely low temperature of the use site

The optimizer series products can meet the parameter adaptation requirements of mainstream modules on the market, and can be widely used in existing power stations using iterated modules and new power stations using the latest modules. They are supported by a large number of actual use cases and have good stability.

03 Determine the PV inverter

As the heart of the PV system, the adaptation of the PV inverter and the voltage optimizer is equally important. Parameters and compatibility are two core elements. Among the parameters, only the DC side parameters of the inverter need to be concerned:

The maximum output current of the voltage optimizer needs to be less than or equal to the maximum current of each input of the photovoltaic inverter.

Note: If the inverter brand parameter table does not specify the maximum input current of each MPPT, it is necessary to calculate the maximum input current of each string based on the maximum input current and the number of MPPTs/maximum number of input channels.

Compatibility is the second core element of the voltage optimizer. If the voltage optimizer is incompatible with the inverter, it may cause the optimizer to fail or the inverter to shut down. Therefore, it is necessary to confirm the existing inverter brand or the inverter brand planned to be used, and confirm whether the inverter brand is compatible with the selected optimizer (some voltage optimizer manufacturers' optimizers are only compatible with their own brand/specific brand or model inverters).

In summary, the initial selection of voltage optimizer needs to meet the following requirements:

Ø The nominal power of the optimizer ≥ the maximum power of the module

Ø The maximum input voltage of the optimizer ≥ the open circuit voltage of the module

Ø The maximum input current of the optimizer ≥ the short circuit current of the module

Ø The maximum output current of the optimizer ≤ The maximum current of each input of the inverter

Ø The selected voltage optimizer needs to be compatible with the inverter used or planned to be used