(1) study on energy saving of external power introduction, transformer, generator and motor system
(2) study on energy saving of lighting system and transmission and distribution lines
(3) study on energy conservation of ac/dc power supply system without interruption
Application status of conventional ac uninterrupted power supply (tower UPS power supply) system
At present, the main data center equipment generally require the ac power input, use more traditional ac UPS power supply system of power supply mode, namely: after ac mains rectifier inverter, UPS power supply system for the data master device provide 220/380 v ac uninterruptible power supply.Its application status is summarized as follows:
(1) the traditional UPS power system adopts N+1 configuration, and the higher-level data center machine room adopts 2(N+1) configuration.
(2) in the early stage of the network, 6 pulse rectifier is adopted for the UPS power mainframe, and in recent years, 12 pulse rectifier is basically adopted.
(3) in order to limit the harmonics generated by the UPS power system, some UPS power systems are equipped with active filters.
(4) the backup time of the battery is mostly configured according to the full load of a single machine for 30 minutes, and some data center configurations reach the full load of a single machine for an hour.
Problems with conventional ac power systems
With the prominent problem of high energy consumption in the data center and the continuous improvement of the reliability requirements for the operation of equipment, the traditional ac UPS power supply mode has the following shortcomings:
(1) using the technique of redundancy weaver, N + 1 or 2 (N + 1) system, during normal operation, UPS power supply of the host load rate are low, and considering the capacity of system configuration actual slants big, makes the system load rate is lower, not run near the best efficiency point, system loss is bigger.After investigation, many large data center room UPS power supply system of single load rate, generally between 10% and 30%, most only 20% or so, in the process of development of data center room UPS power load rate is even lower single single load also accounted for a large part of rate less than 10%.
(2) at present, there is still a UPS power supply with 6-pulse rectifier running in the network, and no corresponding harmonic processing measures have been taken, resulting in large additional power loss of the system.Although some UPS power systems are equipped with harmonic filters for harmonic control, the actual operation situation has not been tracked accordingly after the control, and the control effect cannot be guaranteed.
(3) the backup battery of the ac UPS power supply system can only supply the load after the UPS power inverter. Once the UPS power itself fails, it will still cause the load power failure.
Power line selection
The power line selection needs to be calculated before a reasonable selection can be made. The working current of the commonly used 12V power supply camera is:
General gun or hemisphere: power supply of 500ma-1a can be selected with working current of 200~300mA
Integrated camera: the working current is about 350~400mA and the power supply of 1A can be selected
Small medium infrared camera: the working current is 600-700ma and the power supply of 1A can be selected
Large infrared camera: the working current 1000ma-1200ma can choose the power supply of 2A
Power supply in a set of monitoring system: the camera can supply power independently, or multiple centralized power supply. If multiple cameras provide power in a concentrated way, the required current is the sum of the current of multiple cameras.
Assuming a monitoring system to ten of the hemisphere cameras unified public a power, because the current of a hemisphere is 300-400 ma, so 10 cameras current is 3000 ma - 4000 ma, you should choose 5 a or 6 a power supply.
Power line diameter selection
Assuming that the distance between the four cameras and the monitoring device is less than 40 meters, each camera can separately distribute RVV2 x 0.5 power line to the monitoring host and supply power with small switching power supply.If there are 4 hemispheres or guns, you can also choose 2 12V1A power supply or 1 12V2A power supply. The 4 cameras adopt the method of parallel charging to save wire.If the number of the camera is more, eight cameras, should adopt the high power 12 v dc regulated power supply centralized power supply, this time because the current is too large, the pressure drop on the power cord must be considered, under normal circumstances, the eight cameras in the system, the farthest distance is not more than 40 meters, can be cloth RVV2 * 0.75 wire centralized power supply;If the 16-way system is centralized, the power line of RVV2*1.0 should be selected.The above is about the choice of the power line from the camera to the monitoring host not exceeding 40 meters.
If the distance between the camera and the host machine is more than 40 meters, it is necessary to consider using 220V power supply to change the pressure to 12V to power the camera.In general, the 220 v power supply, as long as the system is not too big, the following eight road, 200 meters distance, can choose the wire RVV2 * 0.5, if more than 8 road, is a high power infrared cameras, consider using RVV2 * 0.75 power supply, the other if the distance is farther, in order to ensure safety, had better use RVV2 * 1.0 wire.
Power line selection method
1. Double stranded power supply
There are five or more types of unshielded twisted wires that can be used as power lines for monitoring cameras to simplify wiring, but you need to make sure that the power is delivered to meet the requirements of the equipment.Such as equipment work power is 10 to 12 VDC, current is 500 ma, twisted-pair cable resistance of 10 Ω / 100 meters (actual use to measure), if the transmit power is 12 VDC, considering the attenuation distance voltage, to ensure the normal use of equipment, transmission power in the 150 meters.
2. Independent RVV line power supply
According to the power of the terminal camera, the power of the general fixed gun machine is no more than 10W, the infrared gun machine is generally no more than 20W, and the ball machine is about 35W.In terms of power alone, RVV2*0.5 line is enough. The line of national standard 0.5 can carry about 1KW load.Long distance, considering the attenuation, it is recommended to use line no less than 1.0.If a small number of cameras within (5) and the interval of the camera and monitor host close (less than 50 meters), each camera can alone cloth RVV2 x 0.5 the power cord to the control room and small transformer power supply.
If the number of cameras is large, the high power 12V dc stabilized voltage power supply should be adopted.In the process of work, want to consider all the total power of the camera and formed by the transmission line voltage drop (taken from the line loss, specifications for 1 m2 of copper wires Ω resistance is 1.8 per 100 m).For the monitoring of a building, two 2.5-6m2 copper core twin-plastic wires are generally used as the main power line during construction, which is led from the monitoring room to the line well, and along the well to the line well of each camera floor.On the floor of each camera power supply, can lead by the lay lines well 1 the RVV2 x 1 or RVV2 x 1.5 (if the layer number of cameras beyond 6) the power cable to the camera power supply, or use the RVV2 x 0.5 sheathed wire lead corresponds to the power supply.
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