Hefei, China – November 20th – Sungrow, a global leader in PV inverters and energy storage systems, today announced the successful conclusion of a comprehensive field test for its latest 1+X 2.0 modular inverter, conducted in partnership with TÜV Rheinland. The test results validate the inverter's Intelligent DC-Side Full-Scope Safety Solution, showcasing major strides in active protection, fault identification, and system-level safety for utility-scale solar power plants.
In large-scale PV plants, the DC side is frequently the system's weakest link. Complex wiring and numerous connection points mean that even a small issue can lead to equipment damage or, in worst-case scenarios, fire. Industry figures reveal that nearly 90% of plant incidents originate from the DC side. Sungrow's 1+X 2.0 modular inverter tackles these vulnerabilities head-on with an upgraded safety framework based on the PDC model—Prevent, Diagnose, and Contain—delivering a proactive and precise approach to safeguarding the entire DC side.
The joint field test rigorously assessed the inverter's performance against four common DC-side risks: short circuits, arc faults, overheating from loose connections, and low-magnitude overcurrent.
Traditional combiner boxes relying on copper fuses for protection often react too slowly during a short-circuit fault, due to copper's high melting point. This delay can cause persistent arcing, potentially burning through the fuse box instantly and damaging surrounding components. Sungrow's combiner box, however, utilizes silver fuses, which have a lower melting point, as its core protective element. Paired with a multi-breakpoint topology design, this setup dramatically enhances arc suppression and response speed.
During testing, the team replaced one silver fuse in the test combiner box with a standard copper fuse to compare their performance under an identical short-circuit fault. When the fault was triggered, the copper fuse produced an intense arc flash and was completely burned through. In stark contrast, the silver fuse safely disconnected the circuit within milliseconds. The fuse body remained intact with no signs of arcing, ensuring a secure and clean power cutoff.
Arc faults rank among the most destructive hazards on the DC side. Under high voltage, arc temperatures can instantly surpass 3000°C, posing a severe fire risk. In the field test, when an arc fault was intentionally initiated, the combiner box accurately identified the arc and shut down the affected branch within a remarkable 32 milliseconds. Simultaneously, the inverter coordinated a disconnection across all combiner boxes within the same unit, swiftly isolating the hazard and preventing its spread—all without any equipment damage or ignition.
"Arc faults within parallel strings present a complex electrical challenge, where signals are often masked by noise, making detection difficult for conventional algorithms," explained a Sungrow expert. "Our pioneering DC parallel arc protection technology, enhanced with an intelligent diagnostic algorithm, adapts protection thresholds for various scenarios and operational states. This allows it to accurately pinpoint arc faults and disconnect to ensure plant safety."
Loose connections at DC terminals are often hard to detect in large plants. Their initial temperature rise is gradual, typically evading traditional overcurrent protection until it's too late, sometimes leading to inverter shutdowns from overheating. The 1+X 2.0 modular inverter counters this with high-precision NTC temperature sensors and intelligent algorithms for continuous temperature monitoring, early warnings, and precise fault isolation.
During the test, a loose connection was deliberately created. The temperature at the affected PV terminal contact climbed slowly, at a rate of about 0.5–2°C per minute, before stabilizing. The 1+X 2.0 system monitored these changes in real time, issued a warning roughly 15 minutes after the temperature surpassed the threshold, and cleanly disconnected the faulty branch—all without impacting the power generation of the rest of the array.
Traditional fuses depend on high fault currents to trigger disconnection. For subtle faults like low-magnitude overcurrent, fuses often fail to react promptly, allowing prolonged current stress that can damage critical components like IGBTs. Sungrow's innovative pyro-fuse protection scheme builds upon traditional fuses by integrating three key mechanisms: active arc control, high-efficiency cutting, and powerful arc suppression.
In the field test, a short-circuit fault was induced. The results demonstrated that the 1+X 2.0's protection system disconnected the faulted circuit in just 1.472 milliseconds. Post-disconnection, the inverter itself was completely undamaged and resumed operation smoothly. By comparison, a traditional fuse solution took 526 milliseconds to disconnect, underscoring the pyro-fuse scheme's superior speed and precision. Furthermore, the pyro-fuse can identify up to 15 different categories of DC faults, enabling proactive, forced disconnection to protect the inverter's integrity.
TÜV Rheinland expert Tian Xingxin, who witnessed the entire field testing process, confirmed that the Sungrow 1+X 2.0 modular inverter and its Intelligent DC-Side Full-Scope Safety Solution successfully passed all challenges. He emphasized the system's leading capabilities in proactive detection, precise disconnection, and comprehensive system-level protection. "This not only provides a verifiable technical pathway for ensuring DC-side safety in utility-scale plants but also sets a valuable reference for the industry to pursue higher-level safety standards," he noted.
As solar projects worldwide trend towards larger scales and higher system voltages, DC-side safety demands are becoming increasingly stringent. The Sungrow 1+X 2.0 modular inverter establishes a new, verifiable safety benchmark for the industry, giving plant operators and investors greater confidence in long-term operational reliability.
Next：None
Previous：How to Maximize Lithium Batteries Performance and Safety in Lowest Operating Temperature
