Miniature PV Inverter

1. Micro-inverter Design Quality Assessment

Could the increasing complexity of micro-inverters introduce hidden safety risks?

There are two fundamental differences between micro-inverters and the components they convert:

A single component is a simple semiconductor, typically a diode, while a micro-inverter is a complex system combining multiple active and passive electronic components along with embedded software. This makes the reliability of micro-inverters inherently more challenging than that of individual components. While a single component can easily last 25 years, achieving the same longevity for a micro-inverter composed of many parts is far more difficult.

Another major difference lies in the power systems across countries. The inverter must adapt to these variations, acting as a critical barrier between the grid and the solar panel. Therefore, solar panels are generally universal, but inverters require specific certifications for each region to meet local standards like voltage, frequency, and safety regulations.

The number of micro-inverters has increased significantly compared to centralized inverters. For instance, a 300W system may use one inverter, while a 250kW system could require over 1,000 micro-inverters. This massive scale leads to fundamental changes at both the power plant and grid levels. As such, the design quality criteria for micro-inverters are much more rigorous than those for components or even centralized inverters.

The first level of assessment focuses on basic electrical specifications—such as power output, voltage, efficiency, weight, THD, PF, appearance, price, and durability. Most manufacturers stop here.

The second level involves global compliance with different national power system standards. For example, Australia has lower certification thresholds, which attracts many Chinese manufacturers. In contrast, North America’s standards are less strict, often favoring local companies and allowing lower requirements for leakage current and DC components. However, as distributed solar grows, these standards are likely to evolve, aligning more closely with European ones.

Ying Weili has conducted comprehensive testing and certifications across numerous countries, including North America, Europe, and Asia. Unlike most competitors, who come from the semiconductor industry, Ying Weili’s team includes experts deeply familiar with power systems.

The third level of assessment involves large-scale user testing. Testing in one country for a short time provides limited insights. In contrast, testing across multiple countries over several years gives a more accurate picture of reliability. Ying Weili tested nearly 20,000 units across 40+ countries in just two years, whereas some competitors only tested in one or two regions, missing critical long-term data.

Skipping thorough testing is risky and costly. Many pioneers have failed due to overlooked issues. The lessons from IT and EV industries highlight the importance of rigorous development processes.

2. Micro-inverter-Based Distributed Systems: More Than Just Inverters

Is it a generator or a power plant? This is a key question.

Micro-inverters, when combined with solar panels, form an ideal generator. Multiple generators together create a power plant. At 300W, this represents a milestone in energy history, enabling individuals to generate meaningful electricity. However, many early adopters missed its full potential.

Distributed systems involve two aspects: benefit distribution and risk distribution. Smaller residential systems focus more on benefits, while larger commercial systems emphasize risk control.

Centralized inverters integrate generation and power plant functions, making them easier to manage. But with micro-inverters, the responsibility shifts. Each micro-inverter doesn’t need to detect leakage or DC components, but the entire power plant does. This means that systems without eGate technology cannot provide the necessary protection, limiting their use to small-scale applications.

The Infineon eGate+ micro-inverter system offers complete safety features, including leakage detection, DC component monitoring, and lightning protection. It allows users to build scalable, intelligent power plants easily.

Currently, only Infineon’s solution offers a truly modular, globally compatible smart grid system. This innovation stems from deep expertise in power systems and advanced electronics.

Whether it's a component or inverter plant, the focus is on the generator itself. However, grid companies care about the overall performance of the power plant.

Distributing solar power brings benefits to end-users, but it also increases the complexity of the grid. With thousands of micro-inverters, the grid faces more challenges in reliability and safety.

For example, a 1MW project using 4,200 micro-inverters poses significant risks if not properly managed. Issues like leakage currents or DC components can endanger lives and damage equipment. Competitors often rely on third-party solutions, which add cost and complexity.

Without real-time monitoring and localization, problems can go undetected. Infineon’s eGate system provides instant fault detection, making it far superior to “pseudo-distributed” alternatives.

The photovoltaic industry should take these risks seriously. Only a fully integrated, intelligent system like Infineon’s eGate+ ensures true safety and scalability.

3. Micro-inverter-Based Smart Grids: Beyond Data Collection

Smart grids are still in their early stages.

Five years ago, Infineon began developing a smart digital power supply. Today, it has delivered a complete smart grid system. This leap represents a major shift in how we think about energy distribution.

With so many micro-inverters, wired communication is impractical. Wireless solutions are needed, but they bring new challenges in real-time data transmission and security.

Many companies, like A and N, rely on third-party protocols that were designed for low-data applications. These systems lack the real-time capabilities and security required for smart grids.

Infineon, on the other hand, has built a strong communications team and developed advanced solutions for industrial networks. This allows it to offer comprehensive smart grid services.

The secondary side of the power grid presents unique challenges. Low-voltage power line carrier communication (PLCC) is still under development, with no industry standards yet. Infineon is leading the way in this area.

As distributed generation grows, the need for secure, reliable communication becomes even more critical. The open architecture of some systems poses risks to user privacy and data integrity.

Looking ahead, the future of energy lies in smart grids. Companies that master core technologies will lead the next phase of the electrical revolution.

As smart grids evolve, they will break traditional boundaries and enable a truly interconnected global energy network. With continued innovation, new business models and value will emerge.

Before entering the micro-inverter market, it's essential to consider the broader implications—from generator design to grid integration. Three key areas must be addressed:

1. Assessing the design quality of micro-inverters themselves.

2. Ensuring safe, distributed operation of power plants.

3. Guaranteeing real-time data and information security within smart grid systems.