Selection and matching of apcups power supply

UPS is a system equipment that connects the battery (mostly lead-acid maintenance free battery) with the host and converts the direct current into the mains power through the inverter and other module circuits. It is mainly used to provide stable and uninterrupted power supply for computers, computer network systems or other power electronic equipment.

Learn about jinsamurai UPS power supply

UPS is a system equipment that connects the battery (mostly lead-acid maintenance free battery) with the host and converts the direct current into the mains power through the inverter and other module circuits. It is mainly used to provide stable and uninterrupted power supply for computers, computer network systems or other power electronic equipment. When the mains power input is normal, the ups will supply the mains power to the load after stabilizing the voltage. At this time, the UPS is an AC type voltage regulator, and it also charges the battery in the machine. When the mains power is interrupted (emergency power failure), the ups will immediately supply the DC power of the battery, and continue to supply the load with 220V AC through the inverter conversion method, so that the load can maintain normal operation and protect the load hardware and software Not damaged. UPS equipment can provide protection for high or low voltage.

UPS reliability

The reliability of UPS depends more on the overall design of power system than on the design of UPS itself. The final way to improve the availability of UPS is undoubtedly to shorten the overall repair time including ups and the whole power protection scheme, and expand the redundancy to the maximum.

For a long time, MTBF (mean time between failures) is a key measure used by UPS manufacturers to measure and explain UPS reliability. However, using MTBF to predict the availability of UPS is actually not convincing.

To illustrate this point, for example, if the MTBF of a UPS is 200000h, non professionals may simply think that the equipment can operate for 200000h without failure (about 23 years). However, in fact, UPS manufacturers cannot and will not carry out fault free operation test for 23 years. Instead, they just calculated an MTBF value based on the expected service life of the ups components. Then, when the shipment volume increases to be statistically significant, the actual performance data of this batch of equipment will be replaced with some preliminary estimates, which may be misleading. For example, if 2500 UPS operate well in the 5-year research period, the MTBF value may be quite high. But if one component of these systems has a service life of only six years, 90% of them may fail in the year after the five-year study period.

Classification of UPS design

1. Power path of backup UPS

When UPS detects power failure, backup UPS can cut off the power supply of IT equipment (LTE) and provide power protection for the system. However, some backup power systems will provide local power protection in case of over-voltage or under voltage, so the use of battery power is limited. It can be seen that although backup UPS can improve efficiency and reduce costs, sometimes the power supply protection provided is not comprehensive.

2. Power path of Interactive UPS

The Interactive UPS usually adjusts the voltage appropriately according to the situation before supplying power to the protected equipment. However, the Interactive UPS must use battery power to prevent various frequency anomalies and power failure 'clearing.

3. Power supply path of dual conversion UPS

Dual conversion UPS can isolate the key load from the mains power supply, so as to ensure clean and reliable power supply for it equipment. Dual conversion UPS consumes more energy than backup ups and Interactive UPS, so their heat dissipation in data center or equipment is higher.

How to improve UPS reliability

1. Add parallel battery pack

The risk of using a UPS with a single battery in series to supply normal load will be greatly increased. If one of the batteries in series is faulty, it will affect the discharge of the whole battery pack, resulting in the failure of UPS power supply. If another battery pack is connected in parallel on the ups, if one battery pack fails, the ups can still be powered by the battery pack of the other level for a period of time, so as to have time to connect the standby generator for power supply or shut down the load equipment calmly.

2. Installation of diesel generator

Battery power supply can only solve the immediate problem. In the face of long-term power failure, even the longest aging battery pack may be "powerless". Therefore, in the case of long-term power failure, it is ideal to use diesel generator as backup power supply.

3. Improve availability by installing UPS in parallel

The redundant design logic is not only applicable to the power protection scheme, but also to the ups design. The reliability of the system can be fundamentally improved by building multiple power supply paths in the power supply design.

The final performance of power supply chain is limited by the weakest link. Therefore, adding multiple redundancy at each point of the supply chain can improve its overall reliability. Therefore, the most reliable transmission system usually consists of multiple independent power supply paths from the main power supply to the power load, avoiding overlapping as much as possible. With redundant power supply system, the county will not shut down it equipment in case of component failure or routine maintenance.