Reference to the UPS selection solution for the communication industry that cannot be powered off (1)

For the wide variety of UPS in the current market and the diversity of working modes, the ideal UPS should be selected and configured. Here we will talk about the details of the selection of medium and large UPS instances in the communication industry communication exchange station. When selecting UPS, you must first determine the type to be selected, and then determine its product based on the specific technical parameter indicators.

1. Selection of UPS Main Performance Parameters

UPS technical parameters are important indicators of UPS quality and are the basis for selection. Whether the UPS can normally and safely supply pure uninterruptible power to the load equipment requires a detailed understanding of its performance parameters. The main technical parameters are as follows.

1. Rated Operation Parameters

1) rated output power; rated maximum output and input current.

2) rated output input frequency: 50Hz in China.

3) the nominal input and output voltages are determined based on the inbound and outbound modes, including single-in-single-out, three-in-single-out, and three-in-three-out, large and medium-sized UPS use three-in-three-out line access mode.

2. input parameters

1) the input voltage range should select a wide range of UPS according to the poor quality of China's power grid. At present, the UPS range designed with Thyristor is-15%, + 10%, and the range of IGBT rectifier is-25%, + 23%.

2) it is best to select 50 + 5Hz with a wider frequency range.

3) Select ± 10% for the AC bypass voltage range. exceeding this value will increase the UPS failure rate.

4) UPS shall have automatic protection functions for wrong three-phase input phase sequence and three-phase missing input.

3. Output Parameters

1) Static Stability of the output voltage, medium and large UPS is ± 1%.

2) The transient voltage fluctuation value of the output voltage is less than ± 5% for medium and large UPS.

3) adjustable output voltage range. medium and large UPS can be adjusted to a minimum of ± 5% from the rated value.

4) output frequency. medium and large UPS instances are 50Hz ± 0. 1%.

5) Output overload capacity. medium and large UPS can meet the requirements of 125% load at 10 min or above and 150% load at 1 min or above.

6) with three-phase 100% unbalanced load capacity, the three-phase voltage difference should not exceed ± 3%.

7) harmonic distortion of the output voltage <2% with 100% linear load.

4. Other parameters

1) The average failure-free time is 20 ~ 0.4 million hours), 15 ~ 0.22 million hours and medium size ).

2) the parallel operation capability requires the UPS to have the direct parallel output capability. The imbalance of the average stream of the output current of each UPS is 2 ~ 5%. The smaller the value, the better. It has the Failover function, but cannot affect the normal operation of the load.

3) remote monitoring, fault alarms, and Operation records should be provided.

4) lightning protection against surge suppression and antistatic discharge should be provided.

5) It has the ABM advanced battery automation management function. Because the quality of the battery directly affects the UPS power supply to the load without interruption. Currently, in most UPS instances, batteries are charged for a long period of time. If the mains supply is normal, only the charging is not discharged. In the long run, the battery plate is passive, reducing the battery capacity, the backup power supply time is seriously affected. The ABM advanced battery automation management system is a kind of "short-term fast Constant Current, charging-Constant Voltage floating charging-long period of small current discharge battery management + Real-Time battery performance aging detection ". integrated battery charge/discharge Management System ", it can also be periodically charged, which can greatly prolong the battery life.

6) matching with the generator set can be implemented because when a generator set is required to bring UPS, the power supply sent by the generator set itself not only has a large voltage distortion, but also its internal resistance is far greater than that of the mains grid, in addition, the non-linear load will reflect a large amount of higher harmonic current to the diesel generator set, which may cause the subsequent load to be burned down, UPS failure, and so on; and the gap between the mains power supply and the generator power supply is, the UPS auxiliary battery has been discharged to the load. Therefore, if a generator set with a power rating greater than the nominal output power of the UPS is used to power the UPS Load, the power should be more than 1.6 times the nominal output power of the UPS.

7) with microprocessor control technology. It can enhance UPS's advantages in fault diagnosis, automatic judgment and handling, various protection measures, strong processing capability, high reliability, and high efficiency.

8) large UPS must have an output isolating transformer. The isolating transformer can first optimize the mains supply and supply the UPS with a relaxed working environment to reduce the UPS failure rate. When the UPS is switched to the bypass, the mains supply is optimized first, this reduces the impact of various pollution sources on the load of the municipal power grid.