UPS power supply system strategy for computer room, redundant power supply equipment ( part 2)

3. Analysis of UPS Selection Principles in Power Supply Systems

3.1 Select high-efficiency equipment

As an indispensable key element in power supply systems, UPS (Uninterruptible Power Supply) requires electrical engineers to prioritize system reliability and consider the external operating environment when selecting equipment. Controlling high temperatures is crucial. Statistics show that increased UPS temperature doubles the activity of internal electronic components, further shortening their lifespan. Therefore, managing the internal temperature of the UPS improves reliability and stability. However, controlling internal temperature requires comprehensive analysis of power consumption. In short, lower power consumption is not always better, nor is higher power consumption always better. To maximize performance, engineers must consider the overall system requirements and set appropriate load power settings.

Specifically, in the common two types of UPS circuit structures—line-frequency and high-frequency—different devices have different linear input specifications at both the output and input ends. They also have different power factors. Statistics show that line-frequency UPSs often have higher power consumption than high-frequency UPSs , and they also have different costs. Furthermore, line-frequency UPS input inverters typically use a full-bridge circuit. In practical applications, to maximize the performance of such a circuit, an isolation transformer is needed. For high-frequency UPS inverters, however, a half-bridge circuit is usually used. Therefore, the spatial and structural layout of such facilities does not require transformer isolation to achieve the desired effect.

Therefore, it can be seen that the increased structural losses in the power frequency turbine system lead to higher transformer losses. From a fault diagnosis perspective, a larger number of devices in a system generally results in a higher failure rate. Thus, power frequency turbines are more prone to failure than high-frequency turbines. Therefore, when selecting a system, engineers and technicians must adhere to the principle of reducing structural complexity and improving overall system stability when arranging equipment to minimize power losses.

3.2 Select equipment with low noise

Generally, to ensure a more scientific, efficient, and stable operation of the power system, electrical technicians need to strictly control equipment noise. Excessive noise can also make the operating environment overly complex, severely impacting operator morale and leading to reduced work efficiency or even operational errors. However, because the input circuit of a line-frequency UPS disrupts the original voltage waveform, it can cause electromagnetic interference to other equipment. Furthermore, the inductors and transformers generate significant audible noise during operation, further worsening the operating environment. Line-frequency UPSs typically use a modulation frequency of around 10kHz, which falls within the range of human hearing, severely interfering with the working environment. High-frequency UPSs, on the other hand, usually operate at modulation frequencies above 20kHz, which are generally outside the range of human hearing, ensuring a relatively quiet working environment. Therefore, from a power supply reliability perspective, selecting equipment with an appropriate modulation frequency is crucial. Currently, high-frequency UPS power supplies with modulation frequencies above 20kHz are relatively common in data center server rooms. In general, when selecting a UPS for a power supply system, engineers and technicians need to consider the overall power consumption of the entire system, as well as the noise level of the entire system, in order to improve the overall operating efficiency of the entire system.