The communication industry heavily relies on UPS systems as a critical power supply solution. As the core of the entire data center, the primary concern for UPS is reliability, followed by safety, energy efficiency, and environmental friendliness. However, talking about green and energy-saving features without addressing fundamental issues like harmonic distortion is essentially meaningless.
In a typical data center power system, components such as transformers, diesel generators, ATS, TVSS, low-voltage distribution cabinets, DC power supplies, UPS, and batteries work together to ensure stable power delivery. Among these, the UPS plays the most crucial role. It acts as both the power source for the connected IT equipment and a load on the utility grid. Ideally, a UPS should behave like a purely resistive load, with an input power factor close to 1, minimizing its impact on the grid. Unfortunately, traditional UPS systems often use 50Hz thyristor rectifiers that introduce significant harmonic distortions into the power grid, making harmonic control a major challenge for users.
Harmonics are not just an inconvenience—they can severely degrade power quality. They consume grid resources, increase voltage distortion, and create compatibility issues between the UPS and the generator. To prevent these problems, the generator’s capacity must typically be two to three times that of the UPS. Otherwise, instability or even shutdown may occur. In practice, some communication departments have experienced unexpected circuit breaker trips due to excessive harmonic feedback from certain UPS brands, leading to costly downtime and maintenance.
The complexity of harmonics makes their control far more challenging than simply improving the power factor. Many people assume that adding capacitors will solve the problem, but this approach works only for linear loads like motors. For non-linear loads such as UPS rectifiers, pure capacitance compensation can actually worsen distortion. Conventional LC filters target specific harmonics, like the 5th harmonic, but they are ineffective against others. The principle of harmonic control is clear: "Who pollutes, who governs."
Most UPS systems today use 6-pulse rectifiers, which require input filters to reduce harmonic distortion to around 7% when fully loaded. However, this drops significantly at lower loads—rising above 15% when the load is halved. Some manufacturers offer 12-pulse rectifiers, which reduce distortion to about 5% at full load, but again, performance deteriorates under light loads. These methods all come with limitations, forcing users to spend extra on additional filtering solutions, creating an expensive and inefficient cycle.
Is there a better solution? Yes—Eaton's online UPS systems use TGRT rectification, which suppresses harmonics to less than 3%, offering a fundamentally cleaner and more efficient power solution. Unlike traditional rectifiers, TGRT uses IGBT technology with a high-frequency pulse width modulation (PWM) method, effectively acting as a 8300-pulse rectifier. This results in near-perfect sine wave input, eliminating grid pollution.
Modern servers, especially blade servers, demand higher power density and often use dual power supplies, requiring redundant UPS configurations like "1+1" parallel setups. This means individual UPS units rarely operate at full load, often running below 50%, or even 25%. In such cases, the full-load efficiency figure becomes irrelevant. Instead, efficiency at light loads is more meaningful. Leading manufacturers now claim 95% efficiency at 50% load, with minimal drop at lower loads. However, many competitors rely on additional options like 12-pulse rectifiers or active filters, which can reduce overall efficiency by up to 4%, resulting in lower real-world performance.
Some UPS models feature a bypass energy-saving mode, where the system switches to bypass power if the grid voltage is stable. While this improves efficiency, it compromises protection. During bypass mode, the UPS doesn't isolate the load from power disturbances, and there’s a risk of power interruption during outages. True protection is only achieved in online double conversion mode.
Finally, modern UPS systems include built-in load testing capabilities, allowing users to perform full-load battery discharge tests without external dummy loads. This helps identify hidden issues, saves costs, and ensures the entire system is reliable and safe. With these advancements, the future of UPS technology looks promising, offering better efficiency, cleaner power, and smarter protection.
Off-Grid Solar System,Solar Energy System,Solar Solution Off-Grid
China Searun Solar Solution Co., Ltd. , https://www.srsolarlights.com