A brief discussion on the characteristics of the new generation of household string inverters

As the installed capacity of my country's photovoltaic power stations increases, power generation and maintainability will become important factors in power station design. String inverters have the characteristics of flexible design, convenient maintenance, and strong adaptability. They can be used not only in distributed rooftop power stations, but also in large ground power stations.

With the continuous development of technology, string inverters have shown a trend of full power range, 1KW-50KW, rich power range levels and lighter design have become the development direction of many inverter manufacturers. At the same time, with the continuous implementation of various Internet access policies, the design of string inverters has also ushered in a new round of challenges. Small power string inverters that are more suitable for home use have become a direction of future development. However, how to stand out from many homogeneous machines is the most direct and realistic problem facing manufacturers, and how to choose a suitable inverter has also become the reality that many owners need to consider most.

The new generation of household string inverters should have higher power density, integrated design, and more practical features. How to achieve these goals is the focus of this article.

The following figure is a comparison of the appearance of GoodWe inverter's first-generation SS and new-generation NS. From the figure, we can see that the overall appearance of SS and NS has undergone a huge change. The NS machine has only 80% of the original SS volume and 70% of the original weight. The small volume and new weight are more suitable for installation and use in different environments.

Figure 1: Appearance comparison between SS and NS

1. Integrated design

The biggest difficulty of small-power string inverters is how to achieve better output characteristics, rich functional experience, smaller size and weight under the premise of ensuring stability and quality at the optimal design cost.

This often requires a clearer understanding and plan of the cost and function of the machine at the beginning of the design. Integrated design is crucial in the design.

GoodWe single-phase single-channel inverter (GW1000-NS~3000-NS) adopts a higher power density design. This solution is contrary to the design concept of existing inverters. It does not adopt more complex topology and overly fancy hardware design. Instead, it adopts simple hardware topology, more advanced software control solution and inverter control algorithm to obtain output characteristics and functions that are no less than other models.

The integrated PCB design solution optimizes not only the material cost, but also the installation cost and maintenance cost. The simple and neat design inside the box gives people a clear feeling at a glance, without cumbersome installation process.

The integrated cabinet design reduces the weight by 30% and the volume by 20% compared to the original product. Based on the overall optimized design, the aluminum-magnesium alloy cabinet, IP65 protection level, and natural cooling are still the consistent features of GoodWe machines.

Table 1 Parameter comparison between SS and NS