Growatt's R&D Path | The Growth of MAC Smart Commercial Inverters

In any era, core technology determines the competitiveness of an enterprise. The reason why those century-old enterprises can stand firm in the fierce market competition is precisely due to the accumulation of core technology.

In 2018, with the changes in photovoltaic policies, the industry has reduced the cost per kilowatt-hour through bidding, and moving towards grid parity is an inevitable trend. Therefore, taking technological innovation as a breakthrough, reducing the cost per kilowatt-hour and reducing dependence on subsidies have become new directions for the healthy development of the photovoltaic industry.

At the same time, the new photovoltaic policy has made industrial and commercial distributed photovoltaics emerge as a new force. Industrial and commercial roofs have large areas, high electricity prices, and great investment value, which have broader development prospects. However, industrial and commercial roofs are very complex. There are good roofs with consistent angles and no obstructions, and there are complex roofs with multiple shadows, multiple angles, high harmonics, and high humidity. The right solution will be the core of the competition.

In mid-2018, Growatt engineers asked: Is it possible to develop an inverter that not only meets the requirements of grid parity with high cost performance, but also has the advantages of "intelligence, high efficiency, high power density, and meeting the needs of small and medium-sized industrial and commercial enterprises"? As a result, the MAC smart inverter was born - an inverter that is truly suitable for small and medium-sized industrial and commercial enterprises in the grid parity era.

Growatt's MAC 50~70KTL3-X LV/MV has sold tens of thousands of units since its launch, delivering high-efficiency benefits to thousands of homeowners while receiving praise from different users.

The inverter is very light and small, easy to install and carry, with OLED display and touch button design, it has a good feel and power generation effect, and is easy to operate and maintain. ——Brazilian user

Elegant and grand appearance, high efficiency, ultra-high ratio, multi-channel MPPT, lower cost, higher profit, intelligent monitoring makes maintenance simple. ——Shandong user

Each of Growatt's products reflects a deep insight into user habits and needs. Every technical detail and functional innovation is designed to meet the most essential needs of users and the market.

MAC Series Inverter Growth Story

1. Survey conducted in June 2018

More than 10 user research engineers conducted a series of preparatory work including user interviews, household surveys, market visits, competitive product analysis, photovoltaic industry development trends, etc. They visited many cities in countries around the world, surveyed thousands of dealers, selected more than 100 key business owners, had in-depth exchanges with the owners, and entered users' real-life scenarios to discover problems.

2. Project approval in September 2018

After preliminary research and technical discussions, the Growatt Research Group began to invest in the project establishment of MAC 50~70KTL3-X LV/MV: to create a cost-effective inverter that not only inherits the high efficiency, safety, reliability and intelligence of the previous generation of products, but also has a small size, light weight and higher efficiency; to meet the needs of small industrial and commercial models; and to strive for a highly intelligent product that can provide affordable access to the Internet.

3. Single board test in December 2018

Process design, basic logic, voltage ripple, current ripple, basic circuit function verification and other tests

4. Centralized and system testing in March 2019

DVT test: debugging of whole machine function and system function, full load, heat flow, voltage and current test, etc., to meet the standards.

The whole machine joint adjustment, harmonic test, reliability test, etc. The test is completed at a level higher than the industry standard.

5. Prototype test in July 2019

All new products from Growatt are tested in advance before being launched on a large scale into the market. The prototypes are tested in the laboratory and on-site by users to provide a baseline performance survey, with an efficiency of 98.8%. The global trial tests exceed the industry standard.

6. Obtained the certificate in August 2019

The product obtained a qualified test report for evaluation, and the final technical indicators achieved were: maximum efficiency of 98.8%, which is more than 0.3% higher than the industry average, with 1.3 times DC over-matching capability; 3-way MPPT to adapt to more complex scenarios; two models with 380V and 480V output, taking into account both low-voltage grid-connected and medium-voltage grid-connected application scenarios; top-level AC/DC secondary lightning protection and other safety detection and protection functions; the industry's highest power density, product weight and volume are 30% less than similar products, and the prototype user experience test results are also satisfactory.

Obtained CQC, IEEE1547, IEC, UL1741 and other national certification reports and certificates.

7. Project completion in September 2019

MAC 50~70KTL3-X LV/MV completed mass production

Growatt MAC Research Team has something to say

The launch of a popular product requires a lot of simulation design and technical verification in the early stage, which takes a very long time. This team of more than 20 people, led by a technical engineer with more than 10 years of experience, collected hundreds of thousands of sets of data and went through hundreds of experiments... It took more than a year, and the exploration was done from scratch and the challenges were overturned and started over again.

MAC products use DC ink all-thin film technology to avoid the defect of limited life of electrolytic capacitors; introduce new heat dissipation methods, and improve product performance and achieve high power density by introducing cross-border vehicle-mounted technology into Growatt product design and process manufacturing; fan speed regulation function reduces noise impact, supports 1.3 times over-allocation and other technologies. The strength of this product lies in its appearance and craftsmanship, internal functions, technical interconnection, intelligent interaction, and scene experience. In every benchmarking parameter of similar products, it is at the top of the industry.

The more complex the multifunctional stacking system is, the more it tests the technical capabilities of the company. The temperature rise and heat dissipation problems caused by the full film capacitor design and the decrease in volume and density have always troubled us. In order to meet the full film capacitor design, we continuously adjust and improve the optimization design of the control parameters; in order to meet the temperature rise standard, through 3 months of overtime single unit verification, whole machine verification, reliability verification and other repeated tests, the introduction and promotion of new heat dissipation methods, and the continuous changes in process design, we finally achieved the industry's highest power density, and the product volume was reduced by 30% compared with similar products.

Many times, we persist not because we see hope, but because we persist we see hope. It is indeed very tiring and hard, but we make improvements every day, so we are excited throughout the whole process. "The person in charge said that the appreciation of users for the product makes all the hard work worthwhile.

A series of fruitful achievements in scientific research technology and business models have confirmed Growatt's ability to steadily move towards its vision of "providing smart and clean new energy to households and business owners around the world." However, Growatt's innovative exploration goes far beyond this.