Tauro guarantees maximum performance for systems in harsh environments

Always thinking about the best generation performance, Tauro inverters can quickly adapt to the most different needs of each photovoltaic installation, and can therefore be applied in different situations and topologies. All machines, whether central or string inverters, always work at maximum power and with a limit temperature determined by the manufacturer.

Above a certain temperature, these devices may be temporarily switched off or operate at reduced power to prevent possible damage to the most sensitive electronic components, thus reducing their useful life. The problem may be linked to a number of factors, such as temperature derating, or derating due to inverter temperature.

What is temperature derating?

Temperature derating can be described as a limitation of the inverter output power., with the aim of protecting it in case there is excessive temperature in the place where it was installed. It is common to come across the following graph in a datasheet of photovoltaic inverters.

Possible causes

Overheating and temperature derating occur for several reasons, including:

• Installation Location: In relation to the location where the inverter is installed, extra care must be taken, as the temperature plays a very important role in the operation of the equipment. Isolated locations, confinement, direct sunlight or even the accumulation of inverters in the same location can cause them to overheat;
• Oversizing: with the overloading of the DC side of the inverter, resulting from the use of a greater number of modules, oversizing guarantees greater energy generation throughout the day, but requires more robustness from the inverter;
• Passive ventilation: If the inverter does not have a cooling system, it may heat up beyond the recommended level, causing a reduction in its output power, especially during peak generation times of the day.

An on-site inspection may be necessary to determine whether the derating function is triggered occasionally or due to a problem. This is why we first need to understand how the derating process works in order to make a proper diagnosis. The figure below shows an example of a power derating curve for a central inverter. In order to prevent its components from overheating, the inverter controls the output power according to the operating temperature.

In addition to reducing power to reduce the internal temperature of components, thermal management can also activate fans, if present. These are called forced cooling or active ventilation inverters. When inverters do not have this technology, they are called natural convection cooling inverters.

Active ventilation solution for Tauro inverters

Regarding active ventilation, this is treated as a maintenance-free cooling system, i.e. in which there is no mandatory need for periodic maintenance. In addition to active cooling, the Fronius Tauro has double-wall insulation. This combination allows the internal temperature and the temperature of sensitive electronic components to be kept at much lower levels, even in extreme heat.

Due to this innovative cooling system, the Fronius Tauro can deliver maximum performance at an ambient temperature of up to 50 ° C. This in turn has a positive effect on the overall performance of the photovoltaic system as well as the service life of the power electronics.

This active cooling system offers a particular advantage in terms of OPEX (Operational Expense) costs, since, unlike some other cooling systems, there are no prescribed maintenance intervals that require the attention of specific specialists. All the advantages of active ventilation have also been covered in the following article: Active ventilation of photovoltaic inverters.

What are the advantages of active ventilation?

We can therefore conclude that the main advantages of an active ventilation system are:

• Longer useful life
• Higher yield
• Flexibility in system design
• Simple and flexible installation
• Low maintenance cost

Double Wall System Solution

At Fronius, we call this two-layer insulation system the Double Wall System, which is an innovative double-wall insulation system on the front of the device. Combined with active cooling technology, the Fronius Tauro can deliver maximum power up to 50°C, even in direct sunlight. The cooling system therefore not only ensures a longer service life of the components and the device, but also works together with the double-wall system to deliver maximum system performance even at very high temperatures.