How to choose the right PV optimiser in one article？

Choosing an inappropriate PV optimiser can cause problems such as reduced module power generation, inverter downtime and damage to the optimiser, resulting in direct financial losses. It is then crucial to choose the right optimiser for your PV system.

1.Determine your needs

Taking Sungo's optimiser series products as an example, different models of optimisers have different functions, which can be freely selected according to the actual situation of PV system.

2.Determine the PV module to be used

When selecting a suitable optimiser, the parameters of the PV module and the inverter need to be taken into account. Among them, the PV modules need to focus on the maximum power, open-circuit voltage and short-circuit current under STC (Standard Test Conditions) conditions, taking the modules of a head manufacturer as an example:

Based on the parameter comparison in the STC condition, the optimiser parameters need to satisfy the following conditions when selecting the optimiser:

1. Nominal power of the optimiser ≥ maximum power of the module
2. Maximum input voltage of the optimiser ≥ open circuit voltage of the module at extreme low temperatures at the site of use
3. Maximum input current of the optimiser ≥ short-circuit current of the module at extreme low temperatures at the site of use

Sungo's optimiser series products can meet the parameter adaptation requirements of the mainstream module on the market, and can be widely used in the stock power stations with iterative modules and the new power stations with the latest modules, and have good stability after a large number of actual use cases.

3.Determine the PV inverter to be used

As the heart of the PV system, the adaptation of the PV inverter and PV optimiser is equally important, with parameters and compatibility being the two core elements. Among them, the parameter aspect only needs to focus on the DC side parameters of the inverter, taking a head brand inverter as an example:

The maximum output current of the PV optimiser needs to be less than or equal to the maximum current of each input to the PV inverter.

Note: If the inverter parameter table does not state the maximum input current of each MPPT, you need to calculate the maximum input current of each string according to the parameters of maximum input current and number of MPPT/maximum number of input channels.

Compatibility is the second core element of a PV optimiser, as a PV optimiser that is not compatible with the inverter may cause the optimiser to fail or the inverter to shut down. It is therefore necessary to check the brand of the existing inverter or the brand of the inverter you are planning to use, and confirm that the brand of the inverter is compatible with the chosen optimiser. (Some PV optimiser manufacturers' optimisers are only compatible with their own brand of inverters.) You can also use Sungo's optimiser products, after a lot of tests, we can be compatible with the mainstream inverters in the market.

In summary, the following requirements need to be met initially for PV optimiser selection:

1. Nominal power of the optimiser ≥ maximum power of the module
2. Maximum input voltage of the optimiser ≥ open circuit voltage of the PV module
3. Maximum input current of the optimiser ≥ short-circuit current of the PV module
4. Maximum output current of the optimiser ≤ maximum current of each input of the inverter
5. The selected PV optimiser needs to be compatible with the use or planned use of the inverter