——————————————————1.What is UPS?
UPS is the abbreviation of uninterruptible power supply system, and it is an important external device that can provide continuous, stable and uninterrupted power supply.
In principle, UPS is a kind of power electronic equipment which integrates digital and analog circuits, automatic control inverter and maintenance-free energy storage device.
Functionally, UPS can effectively purify the commercial power when it is abnormal. You can also supply power to computers and other equipment for a certain period of time when the power supply is suddenly interrupted, so that you have enough time to deal with it;
In terms of use, with the advent of the information society, UPS is widely used in all aspects from information collection, transmission, processing, storage to application, and its importance is increasing with the increasing importance of information application.
—————————————— 2. What types of UPS are there?
UPS can be divided into three categories according to its working principle: standby, online and online interaction.
Among them, our most commonly used standby UPS, such as four-way HO series and SD series, has the most basic and important functions of UPS, such as automatic voltage stabilization and power-off protection. Although the conversion time is generally around 10ms, the alternating current output by the inverter is square wave rather than sine wave, but because of its simple structure, low price and high reliability, it is widely used in microcomputer, peripherals, POS machines and other fields.
On-line UPS has complex structure, but perfect performance, which can solve all power supply problems, such as four-way PS series. Its remarkable feature is that it can continuously output pure sine wave alternating current, and can solve all power supply problems such as peak, surge and frequency drift. Because of the large investment, it is usually used in key equipment, network center and other environments with strict power requirements;
In addition, Stone, APC and other manufacturers also provide online interactive UPS. Compared with standby UPS, online interactive UPS has filtering function, strong anti-interference ability, conversion time less than 4ms, and inverter output is analog sine wave, so it can be equipped with network equipment such as servers and routers, or used in areas with harsh power environment. Especially, the price of four-channel MD series UPS is much lower than that of online UPS, which is a good choice that should be strongly recommended to users.
————————————————————— 3. Why do you need UPS?
According to IDC statistics, 45% of all computer failures are caused by power problems; In China, the average number of power outages is 0.5 times/month in big cities, 2 times/month in medium cities and 4 times/month in small cities or villages. There are at least nine problems in the power grid: power failure, lightning surge, surge, frequency oscillation, voltage mutation, voltage fluctuation, frequency drift, voltage drop and pulse interference. Therefore, from the point of view of improving the quality of power supply, it is necessary to equip the computer with a UPS.
In addition, sophisticated network equipment and communication equipment are not allowed to have uninterrupted power supply. It is self-evident that the network center with the server as the core should be equipped with UPS. Even an ordinary computer, after three months of use, the value of software such as data files has exceeded the value of hardware, so it is very necessary to equip UPS to prevent data loss.
———————————————— 4. What kind of UPS should be equipped?
According to the situation of equipment, power environment and the purpose of power protection, appropriate UPS can be selected. For example, for low-power equipment with built-in switching power supply, standby UPS can generally be selected, and online interactive or online UPS should be selected in places with bad electricity consumption environment, while online UPS can only choose equipment that does not need sine wave alternating current for intermittent time or time.
Four-way UPS provides four solutions according to different situations:
Power supply solution of PC system
Commercial desktop power solutions
Economical small system solution
Key equipment and network center solutions
————————————————— 5. What power supply UPS should I have?
First, determine the power of your equipment. Generally speaking, the power of an ordinary PC or industrial computer is about 200W, that of a Mac is about 300W, and that of a server is between 300 W and 600 W. For the power values of other devices, please refer to the instruction manual of the device.
Secondly, it should be understood that there are two ways to express the rated power of UPS: apparent power (unit VA) and actual output power (unit W). This difference is caused by the existence of reactive power, and the conversion relationship between them is: apparent power * power factor = actual output power.
The power factor of standby and online interaction is between 0.5 and 0.7, and the power factor of online interaction is generally 0.8.
When the equipment is equipped with UPS, the actual output power of UPS shall prevail. Some dealers have intentionally or unintentionally confused the difference between (VA) and (W), which should attract users' attention.
———————————— 6. What's the difference between the centralized and decentralized configuration modes of UPS?
If more UPS devices are needed, you can use "centralized" or "decentralized" devices; The so-called "concentration" means using a high-power UPS to load all equipment. If the equipment is far away, it needs to be wired separately. This method is often used in large data centers and control centers. Although it is easy to manage, the cost is high.
"Decentralized" configuration is a popular configuration method now, that is, according to the needs of equipment, equipped with appropriate UPS. For example, the power protection of a local area network, the server can be configured with online UPS, and each node is configured with backup UPS, which is low in cost and high in reliability.
The advantages and disadvantages of these two power supply methods are as follows:
Centralized power supply mode is convenient for management and wiring, requiring high reliability, low cost and high cost.
The decentralized power supply mode is inconvenient, and the management wiring requires low reliability, high cost and low cost.
UPS needs more professional knowledge, please consult professionals, and they will design a reasonable configuration scheme for you.
————————————————— 7. Why does UPS have to buy famous brands?
The function of UPS products is to guarantee. For users, UPS is often the last line of defense to protect equipment and data security. Compared with other products, "reliability and quality" is more important to UPS, and only famous brand products can have such strength.
At present, the UPS market in China is very prosperous, and internationally renowned brands have basically entered China, such as Meilan Rilan from Europe, Exeter from the United States, APC and so on. Foreign brands have certain advantages in technology, and the price is relatively expensive. The main market share is concentrated in the medium and high-power UPS market (above 10KVA); Since the 1990s, some excellent domestic brands have sprung up in the UPS market. With the continuous pursuit of technology and the advantages of localized production services, they have made remarkable achievements and become the main force in the small and medium-power UPS market. As the only well-known IT vendor that launched its own brand UPS, Sitong UPS is one of the outstanding representatives.
Famous brand products at home and abroad are your reliable choices, and the difference lies in the difference in cost performance. But like other products, the UPS market is mixed. There are many fake and shoddy products, which are generally counterfeit products produced by underground factories in Guangdong, Jiangsu and Zhejiang. These UPS are characterized by cutting corners, low quality and low price, and no guarantee of quality and service. They only attract users at low prices. Rational users should refuse the temptation of low prices.
—————————————— 8. What determines the length of UPS standby time?
This is determined by the energy storage device of UPS. At present, UPS generally uses fully sealed and maintenance-free lead-acid batteries as energy storage devices. The battery capacity is reflected by the index "Ahh", which indicates the time for discharging according to the specified current. The battery with the same voltage has large ampere-hours and large capacity; A battery with the same ampere hour has a large capacity when the voltage is high. Generally, the battery capacity is based on voltage and ampere hour * * *, such as 12V/7AH, 12V/24AH, 12V/65AH,12v/kloc-0.
Generally, standby UPS has built-in 4AH or 7AH batteries, and the standby time is fixed. Online and online interactive UPS has standard models with built-in 7AH batteries and long-term models with large-capacity batteries. Users can determine the battery capacity according to the required standby time.
Battery is an important part of UPS, which occupies a large proportion of value. Its quality is directly related to the normal use of UPS, so we should carefully choose genuine batteries with quality assurance.
———————————————————————— 9. What are the precautions when using UPS?
1) The operating environment of UPS should be well ventilated to facilitate heat dissipation and keep the environment clean.
2) Do not bring inductive loads, such as money counters, fluorescent lamps, air conditioners, etc. , to avoid damage.
3) 3) The output load of UPS should be controlled at about 60% for the highest reliability.
4) The light load of UPS (such as 1000VA UPS) may cause deep discharge of the battery and reduce the service life of the battery, which should be avoided as far as possible.
5) Proper discharge helps to activate the battery. For example, if the commercial power is not used for a long time, the commercial power will be cut off artificially every three months, and UPS will be used to discharge with load, which can prolong the service life of the battery.
6) For most small UPS, turn on UPS after work, avoid starting with load when starting, and turn off UPS after work; For the UPS in the network room, since most networks work 24 hours a day, UPS must also run all the time.
7)UPS should be charged in time after discharge to avoid battery damage due to excessive self-discharge.
——————————————————10. What are the advantages of four-way UPS?
The first is brand advantage. As the pioneer of domestic high-tech industry, "Stone" represents profound scientific and technological background, rigorous business thinking and out-and-out commitment;
Secondly, Stone UPS has a rich product line, which can provide a variety of solutions with high cost performance, and has established a perfect after-sales service system nationwide. Since its establishment, Stone UPS has followed the market strategy of "high-end products, mid-end prices, winning customers with performance, quality and service", attached importance to the interests of partners, and based on the principle of maximizing user value, it has won the trust of users from all walks of life and become an indispensable "bodyguard" for personal computers and network centers, with hundreds of thousands of users spread all over enterprises, institutions, families and other fields.
—————————————11.What are the advantages of a new generation of online UPS-four-way PS series?
PS series is an intelligent pure online UPS successfully developed by Guanghua Stone. Compared with traditional power frequency UPS and online interactive UPS, PS series has the characteristics of high quality, high reliability, high index and multifunction, and is a new generation of fully digital UPS.
PS series working schematic diagram
High frequency advantages of 1.PS series
Firstly, the input part of PS series UPS cancels the power frequency transformer or step-down autotransformer isolated from the mains, and adopts SPWM technology to realize high frequency rectification (AC/DC). On that one hand, the allowable variation range of the commercial voltage is improve; On the other hand, the digital signal processor (DSP) is adopted in the control technology, so that the input current is sinusoidal and in phase with the mains voltage, thus realizing the high input power factor of UPS (PF≈ 1), eliminating the harmonic pollution to the mains and achieving the purpose of environmental protection. At the same time, the reactive power loss is greatly reduced, and the operation cost is obviously reduced.
Secondly, the traditional inverter output power frequency transformer is abandoned, and the high frequency transformer is used to isolate UPS from the mains, which not only has low noise, but also has high efficiency. The inverter control circuit of UPS output stage adopts sine wave direct feedback technology, which makes its adjustment speed fast and far superior to the traditional analog feedback technology. Coupled with a small output filter and SPWM modulation above 20kHz, the dynamic response of UPS is very good, and the output sine wave is very pure and smooth.
In addition, the filter protection technology with excellent performance is adopted in the inverter protection circuit, which makes the inverter not only have strong overload function, but also have strong self-protection ability; The batteries in PS series UPS are also charged by high frequency conversion. When the mains power is cut off and UPS is converted into battery to supply power to inverter, it is also realized by high-frequency conversion and voltage reduction (DC/DC).
Second, the intelligent advantages of PS series
The intelligentization of UPS includes automatic identification and control of system running state, self-diagnosis of system fault, automatic monitoring and management of storage battery, intelligent detection and display of internal information, etc.
In the aspect of system operation state identification and control, internal sensors and state logic can identify the system operation state in time, judge whether the system operation program and operation are normal, effectively prevent the harm of system misoperation to the system itself and load, and improve the reliability of UPS.
Another aspect of UPS intelligence is realized by monitoring the software running in the PC. UPS is connected with PC serial port through RS232 interface, and the monitoring software of UPS runs on PC. The PC sends the inquiry instruction regularly, and the UPS returns the operation parameter information within the specified time. Then the PC further judges the running state and specific components of UPS, issues instructions to intervene and remind maintenance personnel when necessary, and automatically stops the operation of computer or local area network before the end of UPS power supply time.
Three. Network advantages of PS series
On the basis of introducing a large number of microprocessor monitoring technologies, Stone PS series can establish two-way communication regulation and management functions between UPS and computer network, regard UPS as an independent node of WAN, install communication adapters and assign independent IP addresses to UPS. In this way, network administrators or authorized personnel can remotely monitor UPS anywhere on the network in real time just like managing computers. Through this control function, users can monitor the operating parameters of UPS in real time on the computer network terminal (such as input and output voltage, current and frequency, charging and discharging of UPS battery pack and display of voltage value, UPS output power and related fault and alarm information). In addition, users can automatically power on and off the output of UPS at regular intervals on the computer network terminal, and orderly power-off operation will ensure the safety and reliability of user software and data.
In a word, the four-channel PS series UPS adopts MOSFET and IGBT power components, which successfully realizes high frequency, miniaturization and high efficiency, and also prolongs the service life of the battery. Network intelligence technology not only provides a completely reliable network power management, but also provides the best scheme for energy saving. It can be said that Stone PS series conforms to the latest development trend of UPS technology, and it is a highly competitive product with cost performance, which will surely shine in the enterprise UPS market in China.
——————————————————12. What does the battery capacity mean?
Generally speaking, the ampere-hour (C 10) of the 20-hour discharge rate represents the rated capacity of the battery, that is, it is discharged at a constant current for 20 hours at 25℃ until the termination voltage (1.75V/ cell), and 20 times of this current is the capacity of the battery, which is generally expressed by AH number. For example, 12V/ 100AH battery means that the battery can be continuously discharged at a current of 5A(0.05C) to the termination voltage 10.5V for 20 hours. In addition, it should be noted that the discharge time of the battery is not linear with the discharge current. For example, for a battery with 100AH, the discharge of current 100A cannot last 1 hour, but only lasts for several tens of minutes; However, discharging at a current of 1A will exceed 100 hours (this discharge is not recommended).
————————————— 13. Can a standard UPS directly use an external battery as a long-lasting UPS?
Not suitable, because the charging current of standard UPS design is small, and it is limited by heat dissipation conditions. If it is used as UPS for a long time, on the one hand, it will not achieve the purpose of use, on the other hand, it will easily have adverse effects on the use of UPS and batteries, and even damage them.
—————————————14. How to extend the power supply time of the uninterruptible power supply system?
There are two ways to extend the power supply time of uninterruptible power supply system:
1. External large-capacity battery pack: The battery pack with corresponding capacity can be externally connected according to the required power supply time. However, it should be noted that this method will lead to a relatively long charging time of the battery pack, and will also increase the floor space and maintenance cost, which needs careful evaluation.
2. Buy a large-capacity uninterruptible power supply system: This method can not only reduce the maintenance cost, but also make the large-capacity uninterruptible power supply system put into operation immediately if the load equipment is expanded.
————————————15. What are the common power problems? What are the different solutions?
There is a common misunderstanding that the commercial power we use is continuous and stable except for occasional power outages, but it is not. As a public power grid, commercial power system is connected with thousands of loads, some of which are inductive, capacitive and switching power supplies. They not only get electricity from the power grid, but also have adverse effects on the power grid itself and worsen the power supply quality of the power grid. In addition, sudden natural and man-made accidents, such as earthquake, fire, lightning strike, short circuit of power transmission and transformation system, will endanger the normal power supply, thus affecting the normal work of the load. According to the test of electric power experts, the problems that often occur in the power grid that cause interference or damage to computers and precision instruments mainly include the following:
1, power surge: the effective value of the output voltage is higher than the rated value 1 10% for one or several cycles. Surge is mainly due to the high voltage caused by the sudden unloading of large electrical equipment connected to the power grid.
2. High voltage spike: refers to the voltage with a peak value of 6000V and a duration of one ten thousandth of a second to half a cycle (10 ms), which is mainly caused by lightning strike, arc discharge, electrostatic discharge or switching operation of large electrical equipment.
3. Switching transient: refers to the pulse voltage whose peak voltage is as high as 20000V, but its duration is between one millionth of a second and one ten thousandth of a second. The main causes and possible hazards are similar to those of high voltage surge, but the solutions are different.
4. Power sag: refers to the low voltage state where the effective value of the mains voltage is between 80% and 85% of the rated value and lasts for one to several cycles. This problem may be caused by the startup of large equipment, the startup of large motor or the connection of large power transformer.
5. Electrical line noise: refers to high-frequency interference such as radio frequency interference (RFI) and electromagnetic interference (EFI), which can be caused by motor operation, relay operation, motor controller operation, broadcast emission, microwave radiation and electrical storm.
6. Frequency change: refers to the change of the mains frequency above 3Hz, which is mainly caused by the unstable operation of the emergency generator or the unstable power supply frequency.
7. Undervoltage: refers to that the effective value of the power supply voltage is lower than the rated value and lasts for a long time. The reasons include: start-up and application of large equipment, switching of main power lines, start-up of large motors, line overload, etc.
8.power fai 1: refers to the situation that power supply is interrupted for at least two cycles to several hours. The reasons are: circuit breaker tripping, power supply interruption, power grid failure, etc.
There are several different solutions to the above power supply problems, and their effects are shown in the following table:
○ Represents better protection △ Represents limited or condition-based protection × Represents no protection.
——————————16. UPS. Correct use and maintenance of UPS battery.
In the use of uninterruptible power supply system, people often think that the battery is maintenance-free, but ignore it. However, some data show that the failure or abnormal operation rate of UPS host due to battery failure is about 1/3. It can be seen that strengthening the correct use and maintenance of UPS batteries is of increasing significance for prolonging the service life of batteries and reducing the failure rate of UPS systems. In addition to choosing a regular brand battery, you should also use and maintain the battery correctly in the following aspects:
First, keep the proper ambient temperature. An important factor affecting the battery life is the ambient temperature. The optimal ambient temperature required by general battery manufacturers is between 20-25℃. Although the increase of temperature improves the discharge capacity of the battery, the life of the battery is greatly shortened at the cost. According to the test, once the ambient temperature exceeds 25℃, the battery life will be shortened by half for every increase of 10℃. At present, the batteries used by UPS are generally maintenance-free sealed lead-acid batteries with a design life of 5 years, which can only be achieved in the environment required by battery manufacturers. If the specified environmental requirements are not met, the service life will vary greatly. In addition, the increase of ambient temperature will lead to the enhancement of chemical activity inside the battery, which will generate a lot of heat energy, and then promote the increase of ambient temperature. This vicious cycle will accelerate the shortening of battery life.
Second, charge and discharge regularly. The floating charge voltage and discharge voltage in UPS power supply have been debugged to the rated value at the factory, and the discharge current increases with the increase of load. In use, we should reasonably adjust the load, such as controlling the number of electronic equipment such as microcomputers. In general, the load should not exceed 60% of the rated load of UPS. In this range, the discharge current of the battery will not be over-discharged.
Because UPS is connected to the commercial power for a long time, the battery will be in a floating state for a long time under the use environment of high power supply quality and less power failure of the commercial power, which will reduce the activity of mutual conversion between chemical energy and electric energy, accelerate aging and shorten service life. Therefore, it should be completely discharged every 2-3 months, and the discharge time can be determined according to the capacity and load of the battery. After full-load discharge, charge it for more than 8 hours as needed.
Third, use the communication function. At present, most large and medium-sized UPS have operability such as communication with microcomputer and program control. Install the corresponding software on the microcomputer, connect UPS through serial port/parallel port, and run the program to make the microcomputer communicate with UPS. Generally, it has the functions of information inquiry, parameter setting, timing setting, automatic shutdown, alarm and so on. Through information inquiry, we can get information such as mains input voltage, UPS output voltage, load utilization rate, battery capacity utilization rate, internal temperature, mains frequency and so on. By setting the parameters, you can set the basic characteristics of UPS, battery life and battery exhaustion alarm. Through these intelligent operations, the use and management of UPS power supply and its storage battery are greatly facilitated.
Fourth, replace the used/bad batteries in time. At present, the number of batteries equipped with large and medium-sized UPS power supplies ranges from 3 to 80, or even more. These single cells are connected by circuits to form a battery pack to meet the needs of UPS DC power supply. In the continuous operation and use of uninterruptible power supply, due to the differences in performance and quality, it is inevitable that the performance of individual batteries will decline and the storage capacity will not meet the requirements. When one or more batteries in the battery pack are damaged, the maintenance personnel should check and test each battery to eliminate the damaged battery. When replacing a new battery, you should try to buy the same model battery from the same manufacturer, and it is forbidden to mix acid-resistant batteries with sealed batteries and batteries of different specifications.