Hoymiles launches 3rd generation of microinverters in the Brazilian market

Nowadays, we can no longer talk about energy conversion equipment technology in the photovoltaic sector without mentioning microinverters. 

With innovative technology, high efficiency, practical installation and the ability to overcome the main obstacles that significantly impact energy generation, these devices are becoming popular with integrators, with a strong tendency to dominate the solar microgeneration market soon. 

What was previously an alternative for small installations is now also becoming a reality in larger projects.  

Hoymiles 

Hoymiles is a Chinese manufacturer specialized in MLPE (Module Level Power Electronics) solutions, founded in 2008, at the National Power Electronics Laboratory of China, based at Zhejiang University in a partnership between university researchers and the Hangkai group, the which denotes the company's philosophy focused on research and development. 

With an R&D department that has 25 masters, ten doctors and three post-doctors, the company is always innovating and launching equipment with the highest technological level, following innovation trends in the photovoltaic market.

Understanding the potential of MLPE technology, Hoymiles invested heavily in the micro inverter sector, developing innovative models year after year, starting with the one-module line up to the model we will analyze today: the four-module version of the third-party HM 1500 line. generation.

Third generation 

The new line of third generation Hoymiles microinverters, launched this year, is another step of innovation achieved by the company, with a new internal control system and updated software in all models of the generation. 

Among other things, this new generation brings a series of improvements such as:

• More assertive and simple monitoring, where information is more easily found.
• More accurate alarm classification with approximately 30 alarms, making it easier to diagnose a possible anomaly in the system and correct the problem promptly.
• More robust AC parameter configuration, with more than 50 new control functions, which makes the equipment more versatile, adapting more easily to the different conditions imposed by local networks.
• Command feedback system, which makes it possible to check whether the equipment has made the necessary adjustment.
• More efficient MPPT algorithm, in which the search for the highest power point (MPP) is done more precisely and quickly, directly influencing the generation of the system.

HM model 

The HM line imported to Brazil exclusively by Genyx Solar Power received, in addition to the previously mentioned improvements, two new modifications, with the aim of increasing its performance: an external antenna to improve communication and reactive control software, to adapt the equipment to some of the requirements of certain installations.

External antenna

Microinverters are designed to be installed next to modules, so they do not have a data display, as it would be necessary to remove the modules to view any information. Therefore, in order to monitor the generation of the system, a monitoring system is necessary, which in turn will access all data in a storage “cloud”. 

To achieve this, Hoymiles equipment uses the DTU (data transfer unit) device, which is nothing more than a communication bridge between the microinverter and the Hoymiles data storage system. 

This communication is done via radio frequency, in the 2.4 Ghz band. Because of this we have a shorter wave, which makes it less efficient at bypassing and penetrating objects. Added to this is the fact that some bulkheads, such as concrete and metal surfaces, promote an even greater “shielding” effect, and as a result, communication between the microinverter and the DTU could be impaired. 

With that in mind, the Hoymiles removed the communication antenna from the equipment encapsulation, bringing it to the outside in order to overcome all these adversities (natural in any installation with microinverters) and promote efficient communication. Furthermore, in the new third generation DTUs this communication capacity is even better, due to the new internal hardware of the DTU.

Reactive control (power factor adjustment)

Photovoltaic inverters inject active power into the electrical grid, which comes from the modules. This injection “worsens” the power factor of the installations, since, from the distributor's point of view, the consumer starts to use less active energy from the electrical grid. 

To overcome this situation, capacitor banks or inductors are normally used. The HM model has software to control the power factor, being able to adjust it from 0.8 lagging to 0.8 leading, thus performing the function of traditional capacitor/inductor banks. 

The microinverter behaves like a controlled current source, with the amplitude and phase being managed by the control software, thereby adjusting the power that is delivered to the grid. 

All of this adjustment is done remotely through the equipment's control commands, which allows for quick correction, without the need to travel to the installation location.

Commands

The HM line has a wide list of available adjustments, which makes the model even more flexible and capable of operating in the different types of networks found in Brazil.  

In addition to the traditional AC voltage limits and reconnection time, in this model we can configure a huge list of parameters, including the so-called “trip time”, which is the standard time in which the equipment continues operating before alarms are activated, which It is extremely important, as it helps the system to absorb small fluctuations in the network without any damage, which are generally short-lived and in other cases would lead to early shutdown of the equipment. 

A complete analysis of all possible adjustments is a topic for a future text, as this is a complex subject that requires greater depth.

Conclusion

Focused on specific corrections and significant improvements to internal software, the new generation of Hoymiles micro inverters has achieved high performance in practice, overcoming some of the adversities of the old generation. 

The greater number of adjustable parameters makes the HM line highly flexible and prepared for the most diverse practical situations, encountered daily by integrators. 

Its external antenna provides a stable connection and security when sending monitoring data to the server, which makes it highly reliable. Its power factor correction software gives the equipment even greater versatility. We can summarize the new model as HM 1500 as reliable and versatile, being a great option to adapt to the high demands of the national photovoltaic market.