I. Industry Background
Against the backdrop of accelerating global energy transition, photovoltaic power generation is experiencing rapid growth thanks to technological breakthroughs and cost reductions, driving expansion across the entire industry chain. As a core component of distributed photovoltaics, microinverters are rapidly increasing in penetration due to their high safety and single-module optimization capabilities. Data shows that the market size will reach a compound annual growth rate of 34.3% from 2023 to 2025, and is expected to exceed 35.4 billion yuan in 2025, marking the industry's entry into a phase of development characterized by both scale expansion and technological upgrades.
II. Application Demand
With the expansion of the industry and technological advancements, the end-market performance requirements for microinverters are focusing on three key areas: power generation efficiency (≥95%), system stability, and grid compatibility. To address the quality concerns raised by the rapid growth of distributed photovoltaics, the government has successively introduced a number of standards and regulations. These standards strictly regulate the technical specifications and testing methods for microinverters in areas such as conversion efficiency and islanding protection, establishing a safety-focused protection system and providing fundamental support for the transformation of new power systems.
III. Testing Difficulties
The challenges of testing microinverters during the charging and discharging process primarily lie in the complexity of the test items and data analysis.
(1) Difficulty in low-power, high-precision measurement: The voltage and current ripples of micro-inverters at low power are relatively high, which can easily cause power calculation errors due to ripples.
(2) Difficulty in component monitoring and performance evaluation: Micro-inverters are usually equipped with one inverter for each or several photovoltaic modules, presenting a full parallel structure. Although they can achieve module-level MPPT and reduce the impact of shadows, they also make wiring complex and monitoring difficult.
(3) Difficulty in high-frequency switching signal processing: Micro-inverters use high-frequency PWM modulation (switching frequency is usually 10-50kHz) internally, and the output current contains a large amount of high-frequency harmonics, which can easily interfere with harmonic calculations. Low-bandwidth power analyzers cannot measure high-frequency signals.
(4) Poor testing convenience: Micro-inverters often need to be tested on-site, especially in installed distributed systems. For these scenarios, most full-width power analyzers currently on the market are difficult to operate in a small space, and the experience and convenience are poor.
IV. Solution
Based on more than 30 years of technical accumulation in the field of test and measurement, Ainuo Instruments has innovatively launched a series of multi-channel power analyzers to address the core pain points of dynamic efficiency measurement and complex harmonic analysis faced by inverters in R&D verification and production testing. It has the characteristics of wide bandwidth, high precision, multi-channel harmonic analysis and multi-channel frequency measurement, which not only significantly improves the accuracy and efficiency of product testing, but also becomes an indispensable key tool to ensure the quality control of products from production to application.
(1) High-precision measurement: The basic accuracy of AN87400 is 0.05% reading + 0.05% range, and the current measurement range is 0~20A, which meets the high-precision measurement requirements of micro inverters.
(2) Multi-channel measurement: AN87400 can simultaneously measure the voltage, current, and other parameters of 4 channels. It can realize testing when one micro inverter is driving multiple photovoltaic modules, greatly improving the monitoring efficiency and accuracy, and solving the problem of monitoring difficulties caused by the large number of modules and complex wiring of micro inverters.
(3) High bandwidth and filtering support: The AN87400 has a bandwidth of 100kHz and two internal filtering circuits (500Hz and 5.5kHz), which can capture high-frequency components and avoid spectrum aliasing.
(4) Perfect size: For field test scenarios, the AN87400 adopts a compact design of 3U half width and has 4 channels. It can not only meet the efficiency test between three-phase AC and DC, but also provides a better experience and greater convenience than full-width power analyzers.
V. Conclusion
Ainuo Instruments has been focusing on research and development for more than 30 years. The compact multi-channel power analyzer AN87400 series launched adopts a high-speed FPGA and ARM processor dual-core architecture and is equipped with a 16-bit high-precision AD converter, showing excellent performance in the field of inverter power analysis. With its wide-band measurement capability, this product can accurately capture various standard and non-standard sinusoidal waveform load characteristics, providing reliable data support for photovoltaic system efficiency optimization. Its innovative hardware design not only fully meets conventional needs such as harmonic analysis and conversion efficiency testing, but has also been verified through large-scale applications by leading companies, becoming a widely recognized professional solution in the inverter testing field.
