Preventing data center UPS power supply from going offline

The UPS AC power supply system is different from the conventional -48V DC power supply system. Its characteristics are that the UPS power supply equipment has the requirements of initial phase angle and frequency synchronization, and the output voltage is high, which is the AC 380V power supply voltage. The parallel operation requirements are much stricter than those of the DC power supply system, and it is more complicated to implement. If multiple UPS devices work in parallel, once the system fails, it is easy to cause a chain reaction, resulting in large-scale power outages. In addition, once the UPS power supply system is put into operation, it cannot be stopped. Shutdown means failure. How to ensure the safe power supply of the UPS power supply system has become the most important issue in the current professional power supply management.

Choose the right equipment

After the construction project is determined, choosing the best equipment is the premise for the safe operation of the system in the future. Based on the group's centralized procurement, the technical indicators and user usage of various UPS equipment are investigated, and the advantages and disadvantages of technical indicators are used as the main selection criteria. On the basis of moderate prices, the brand products of UPS equipment are determined to lay the foundation for the stable operation of the system.

Develop reasonable system equipment configuration and power supply plan

A reasonable system configuration plan is the basis for ensuring safe power supply. In the process of formulating the plan, you cannot just listen to the manufacturer's ideal propaganda of multiple parallel machines. When the system is running normally, each UPS device only bears 40% to 50% of the load to ensure a certain degree of redundancy. Once a UPS in the system fails, the other or two UPSs can fully bear the normal power supply of the system. In the power supply plan, choose a server with dual power ports, or use a dual bus output power supply method to eliminate power supply bottlenecks and ensure power supply safety. In addition, special requirements are put forward for the output distribution cabinet. In order to avoid output circuit breaker failure, the output distribution cabinet is required to be equipped with a spare circuit breaker to prevent power supply interruption caused by circuit breaker failure.

Avoid overloading the UPS

When using UPS, you also need to calculate the load size to avoid excessive or small loads. Excessive loads will cause the UPS to work in an overload state for a long time, thereby shortening the service life of the UPS; if the load is too small, the UPS working circuit will work in an abnormal state for a long time, which is also harmful to the UPS.

The reasonable load should be controlled between 50% and 80%. Practice has shown that the UPS output load is controlled at about 60% for the best reliability. When the UPS is overloaded or the inverter fails, it will switch to bypass mode. At this time, the UPS does not have a backup function, and the power used by the load is directly supplied by the power system.

Strict acceptance

Before each newly built UPS power supply system is officially put into use, each UPS power supply device is subjected to comprehensive tests in various states, including: single machine half-load test, single machine full-load test, single machine overload test, multiple UPS equipment parallel full-load test, system bypass operation test, UPS operation test under battery power supply state. In particular, it simulates the situation that when any UPS in the system stops operating due to a fault, the remaining UPS equipment operates at full load. At the same time, the battery pack's own discharge quality and the temperature rise of each component of the UPS equipment under various states are detected.

Strengthen the management of battery

In order to understand and grasp the quality of the battery pack of the UPS power supply system at any time and ensure the safe and reliable power supply of the system when the city power is cut off, if there is no good battery pack as a backup or if there is no knowledge of the quality problems of the battery pack itself, the battery pack configured in the system will become a "decoration" in the ears of a deaf person. Therefore, paying attention to the management of the UPS system battery is an important measure to ensure the safe power supply of the system.

Use of AC voltage stabilizer

After using UPS power supply, there is no need to add AC voltage stabilizer. If it must be added, it should be added before UPS, that is, the city power first passes through the AC voltage stabilizer, then through UPS, and then to the load. ■