With the development of Cell and PV module technology, various technologies such as half cut cell, shingling module, bifacial module, PERC, etc. are superimposed on each other. The output power and current of a single module have increased significantly. This brings higher requirements to inverters.
High-Power Modules requiring Higher Current Adaptability of Inverters
The Imp of PV modules was around 10-11A in the past, so the maximum input current of the inverter was generally around 11-12A. At present, Imp of 600W+ high-power modules has exceeded 15A that is necessary to select an inverter with a maximum 15A input current or higher to meet high power PV module.
The following table shows the parameters of several kinds of high-power modules which used in the market. We can see that the Imp of the 600W bifacial module reaches 18.55A, which is out of the limit of most of the string inverters on the market. We must ensure the maximum input current of the inverter is greater than the Imp of the PV module.
As the power of a single module increases, the number of input strings of the inverter can be appropriately reduced.
With the increase in the power of PV modules, the power of each string will also increase. Under the same capacity ratio, the number of Input Strings per MPPT will decrease.
Which Solution Renac can offer?
In April 2021, Renac released a new series of inverters R3 Pre series 10~25 kW.Using the latest power electronics technology and thermal design technology to increase the maximum DC input voltage from the original 1000V to 1100V, it allows the system to connect more panels, also can save cable costs. At the same time, it has 150% DC oversize capability. The maximum input current of this series inverter is 30A per MPPT, which can meet the needs of high-power PV modules.
Taking 500W 180mm and 600W 210mm bifacial modules as example to configure 10kW, 15kW, 17kW, 20kW, 25kW systems respectively. The key parameters of the inverters are as follows：
Note:
When we configure a solar system, we can consider DC oversize. DC oversize concept is widely adopted in solar system design. Currently, PV power plants worldwide are already oversized on average between 120% and 150%. One of the main reasons to oversize the DC generator is that the theoretical peak power of the modules is often not achieved in reality. In some areas where with insu fficient irradiance, positive oversizing (increase PV capacity to extend system AC full-load hours) is a good option. A good oversize design could both help the system close to full activation and keep system under healthy condition, which makes your investment worthwhile.
The recommended configuration is as follows:
According to the calculation, the Renac inverters can perfectly match the 500W and 600W bifacial panels.
Summary
With the continuous improvement of module’s power, inverter manufacturers need to consider the compatibility of inverters and modules. In the near future, the 210mm wafer 600W+ PV modules with a higher current are likely to become the mainstream of the market. Renac is achieving progress with innovation and technology and will launch all new products to match with high Power PV modules.