A detailed description of UPS Power technology

UPS is a high-quality, high-reliability independent power supply, is a static type of battery uninterruptible power supply device. It consists of a rectifier, an inverter, an AC static switch and a battery pack. At ordinary times, the mains power through the rectifier into a DC battery floating charge, while the inverter output high-quality AC purification supply for the important load, so that it is not subject to mains voltage, frequency, harmonic interference. When the mains power outage, the system automatically switch to the battery group, battery discharge, the inverter to the important load power supply.

GB50052---1995 "Power supply and distribution system design code" in the mandatory provisions: "The first load of particularly important load, in addition to two power supply, there should be additional emergency supply." "Diesel generators can be used as emergency power supplies, but their response speed is too slow to match modern communication and network information streams." Therefore, some important departments and systems in the project must consider uninterruptible power supply ups.

　　AC Uninterruptible Power supply system

The AC uninterruptible power supply system should be designed and operated under the following conditions:

(1) The power supply reliability requirements are high, the use of standby power supply automatic mode or diesel generator set emergency self-starting mode, etc. still can not meet the requirements.

(2) General voltage stabilized frequency equipment can not meet the requirements.

(3) need to ensure that the sequence of power outages when the safety.

(4) When the electronic computer system is controlled in real time.

(5) Computer system network operation.

Computer equipment on the power requirements of high quality, not only requires the use of uninterruptible power supply system, but also requires the supply voltage fluctuations within a certain range to work properly. Network data transmission equipment requires the fluctuation of supply voltage within ± 5%.

　　Features of UPS

UPS is a high-quality, high-reliability independent power supply, is a static type of battery uninterruptible power supply device. It consists of a rectifier, an inverter, an AC static switch and a battery pack. At ordinary times, the mains power through the rectifier into a DC battery floating charge, while the inverter output high-quality AC purification supply for the important load, so that it is not subject to mains voltage, frequency, harmonic interference. When the mains power outage, the system automatically switch to the battery group, battery discharge, the inverter to the important load power supply.

UPS's uninterrupted characteristics reflected in its "synchronous switching" work program, when the mains and inverter switching, its control system will be timely to detect the synchronization range of mains, in the power supply does not exceed the time limit, the inverter to achieve "first-pass-after-break" of the electricity, so as to ensure that the system of "non-intermittent switching."

UPS products on the market, their capacity specifications are roughly 0.25, 0.4, 0.6, 1, 2, 3, 4, 5, 10, 15, 20, 40, 60, 80, 100, 120, 160, 200, 300, 400, 500, 600, 800, 1000kv a, etc. and has formed a series of products. Generally by IS0G00L international quality Standards certification, UL safety standards and CE anti-electromagnetic interference certification and marking. Most of the PWM pulse width FM technology, PIGBT High-efficiency power devices, microprocessor master/Slave control technology, can be dual-machine or multi-machine parallel. It has the functions of battery test and maintenance, microcomputer monitoring and remote communication, and the components are standardized, modularized and interchangeability, and have good performance such as wide voltage input, high efficiency output and high overload capability.

　　Power supply mode for UPS

UPS power supply Operating mode according to the power supply reliability and continuity requirements can be divided into single-type, parallel, redundant and parallel redundancy, etc. according to the requirements of power supply reliability and management convenience can be divided into decentralized, centralized, decentralized and centralized combination of three ways. Distributed UPS power supply with a relatively small device capacity, short support time, suitable for some office areas and control rooms; centralized UPS power supply for a number of long-term support and larger computer network room. According to the needs of party A to determine which UPS power supply mode and capacity. A centralized set of UPS power capacity statistics is required by the designer to work closely with the owner and consider the conversion efficiency of the selected UPS products. Especially when power is large, UPS conversion efficiency is very important, high efficiency can save the initial investment and long-term energy loss costs.

In general, the computer room power supply using 10 UPS backup battery combined way more. Under normal circumstances, the mains power supply to the computer equipment after the UPS stabilized frequency stabilizing, to ensure the power quality of the computer equipment; When the power outage, the backup battery through UPS inverter power supply to the computer equipment, to ensure the power of the computer equipment. Power and UPS backup battery through the electrostatic conversion switch, to ensure that the computer equipment without instantaneous electricity.

UPS power supply for centralized mode, should also fully consider the UPS Room equipment layout, feeder laying, cooling of the main cabinet and the whole room noise reduction measures, etc. for distributed UPS power supply, scattered throughout the UPS capacity is very small, the above problems can not be considered. However, the UPS power supply should be from the dual power end of the switching distribution cabinet (box) of the outlet circuit, can not be connected from the ordinary socket.

When designing a UPS power supply solution, it is also very useful to use a decentralized small UPS power supply as a back-up power supply in a single-stage power supply mode, which is scattered throughout the main control room.

　　Try to avoid over-current charging

Over-current charging is easy to cause the internal positive and negative plate bending, so that the active material off the surface of the plate, resulting in the battery can be used to reduce the capacity, the situation will cause the battery internal plate short circuit and damage.

　　Try to avoid battery over-voltage charging

Over-voltage charging often causes the water contained in the battery electrolyte to be separated into hydrogen and oxygen to escape, thereby shortening the life of the battery.

　　Replacement of batteries with reduced activity and excessive internal resistance

(1) With the UPS power usage time extension, there will always be some of the battery charge and discharge characteristics gradually become bad, the end voltage significantly decreased, the performance of the battery can not rely on the UPS power supply internal charging circuit to solve, continue to use the hidden danger, should be replaced in time.

(2) as the internal resistance of the battery increases, when the battery is charged with the normal charge voltage, it should be replaced in time to restore the battery's charging characteristics. The internal resistance of the battery is generally 10--30mn, if the internal resistance of the battery exceeds 200m bar will not be enough to maintain the normal operation of the UPS, the high resistance of the battery must be replaced.

　　Avoid mixing old and new batteries or charging new and old batteries

Because the internal resistance of the new battery is relatively small, and the internal resistance of the old battery has a different degree of increase, when the old and new batteries are mixed together to charge, due to the old battery's internal resistance, the partial pressure will be relatively large, very easy to cause over-voltage charging phenomenon, and for the new battery, the internal resistance is small, charging voltage So in the charge and discharge process should avoid new and old battery fake.

　　Battery usage Environment

Battery life and environmental temperature is closely related to the battery at a lower temperature, the zinc plate in the battery is easy to powder, loss of storage performance, resulting in permanent damage; When the temperature is too high, the capacity of the battery will also decrease, causing permanent damage when the condition is severe. According to the technical specifications of the battery manufacturer, the best operating temperature of the battery is 2~25℃, which can prolong the service life of the battery in this temperature range.

In short, do a good job of UPS battery maintenance, can reduce UPS failure, improve the stability of the system operation. Battery maintenance can improve battery life.