Guarantee of safe operation of power system -- UI power sup

UI power supply is an energy storage device, its internal components are mainly composed of battery pack, rectifier and inverter, static switch and other components. Under normal working conditions, it can be used as a protection device with stable voltage and frequency output to protect the power supply. In the process of use, the electric energy is stored in the battery in the form of DC, which makes UI output voltage in the case of external power failure. Because UI can purify the power supply and provide uninterrupted power supply. With the rapid development of Internet technology, it has been widely used. In addition, UI has important application value in medical, aerospace, industrial control and other fields. In principle, UI system is a kind of equipment which integrates analog circuit, digital automatic control inverter and maintenance free energy storage device. Due to the high integration of functions, this type of equipment can meet a variety of different use requirements, and because it can integrate different components, it can make the system occupy less space during operation and improve the system In addition, it can purify the power supply in case of abnormal power supply, and temporarily supply power to the computer in startup state when the power supply is interrupted, so as to reduce the impact of sudden power failure on relevant production operations. 1. UI operation mode: in the general use process, UI can switch four operation modes according to different scenarios, namely normal operation mode, power failure mode, standby power mode and maintenance bypass mode. 1 normal operation mode: under normal AC power supply, the sub rectifier in UI converts AC power to DC power, then supplies power to the inverter and charges the battery at the same time. In the process of AC power conversion, the power supply is purified to reduce the abnormal surge, noise and frequency instability and other problems in the city power supply, so as to ensure the more stable power supply. Provide more stable power supply for related equipment and system, reduce the impact of unstable power supply on system operation; 2. Shutdown mode: when the power supply is unstable, the power supply may be unstable. When the relevant components are in abnormal state and can not provide effective power supply, the built-in battery pack in UI system can temporarily provide power for the inverter to ensure the normal completion of the AC output process, without interruption during the process, so as to ensure the output load can be protected and ensure the stable operation of the whole system; 3. Standby and bypass mode In the process of circuit use, the failure of different links may lead to the loss of power supply function, and the power supply plays a very important role in all production activities driven by electric energy. If a sudden power failure occurs, not only the whole production process will be interrupted, but also the service life of the equipment will be seriously affected, For enterprises using computers for production, if the power is suddenly cut off, the operating system will be too late to save the data. If the power supply is unstable for a long time, the normal operation of relevant enterprises will not be guaranteed. In order to better develop the relevant industries, it is necessary to timely prevent the sudden power failure. The prevention work is divided into two directions. The first direction is to ensure the good operation of the whole power system and reduce the possibility of system equipment failure as far as possible. The other direction is to intervene and reduce the actual power outage caused by the influence of technical conditions The impact on the system caused by this situation.Generally speaking, when the temperature in a certain area of the system is high, it may cause the use failure of components, cause the fuse to blow, and cause the short circuit fault. In case of the above faults, the inverter will automatically cut off the circuit to prevent further expansion of the loss. If the bypass AC power supply is in normal working state, the static switch will transfer the power supply task to the bypass AC power supply, so as to ensure the normal operation of the whole system and prevent power failure. If the bypass AC power supply is also in fault condition at this time If the system can not be supplied with power, the maintenance bypass switch should continue to supply power to ensure that the system will not be powered off immediately in a short period of time. In this process, the alarm device will be used to give the relevant personnel a part of reaction time for emergency treatment, so as to reduce the loss caused by sudden power failure. Second, the application of UI in electric field. The special UI power supply of power plant is a medium power supply system with three-phase input and single-phase output. The reason why this structure is selected is that most of the power plant loads are single-phase loads. The advantage of this design is that it can simplify the corresponding distribution lines and facilitate the professionals to carry out regular maintenance of the lines. However, the three in and single out UI is a purely unidirectional design of the internal circuit, which mainly shows that the inverter is unidirectional output. After the corresponding transformation of the three in and one out transformer is added to the original basis to carry out the transformation. However, such a transformation result will make the operation state of the whole system unstable. In the process of long-term use, it will cause some hidden troubles and affect the service life and safety of the system. 　　  Generally speaking, the operation efficiency of the whole system will be reduced due to the increase of transformer in the process of use. Generally speaking, the highest working efficiency is only 95% of the normal working efficiency. On the other hand, due to the unbalanced current of 1 / 3 of the transformer, the available capacity of UI will be affected and a certain reduction will be caused The capacity of UI host with higher apparent power is generally twice of the rated output capacity. Due to the addition of different components in the system, the size of the host needs to be further increased. As a result, the optional range of the host placement area will be reduced, and the corresponding cost will also rise, resulting in the increase of the purchase cost. 　　  After comparing the difference between a normal UI host and a modified transformer, we have conducted a comprehensive analysis on the use cost and purchase cost of the two. It is found that the most economical and effective scheme is to use the normal UI system in terms of the stability of long-term use or the investment of purchase cost To choose a real three in one out UI, we should not only consider the immediate economic benefits, but also take a long-term view and analyze the whole process with dynamic thinking. Only through the analysis of this process can we find that the real three in single out transformer can ensure the safety and efficiency of the whole system operation process. In the UI efficiency design and selection, it should be noted that the inverter of UI directly converts DC power to AC power for output. 　　  In industrial production, the general DC voltage is about 400 ~ 460 V, while the voltage specification used in power plant is 220 v. due to the difference between the voltage specifications between the two parts, it is necessary to carry out conversion, which will lead to a problem. In the process of DC voltage reduction, the switching current of inverter will increase, and the loss is proportional to the square of current With the continuous increase of current, the current loss in the process is also increasing, which makes the efficiency of the whole system decrease. Moreover, in the process of use, large current needs to be equipped with high-capacity power switching devices, and lower DC voltage also needs higher transformation ratio transformer. These hidden expenses will increase the operating cost of the whole system. If we consider the wear and tear of the equipment after a period of time, and the cost of replacing aging parts, the investment in the whole cost will be very large. Therefore, when selecting the configuration, we must select the most suitable equipment according to the actual production situation, reduce the additional cost increase in the process, and ensure that the whole cost can be in a controllable state. In order to further improve the reliability of the power supply process, the general power plant needs to configure two WPS to form an anti fish system to supply power to the load. In addition, there are isolation transformer and AC voltage regulator, which are connected into the system as bypass power supply, so as to ensure that the whole system can be in stable and normal operation state.III. precautions for use of UI system
During the use of UI, the temperature requirement of external environment is not high. Generally, UI can work normally within the range of 5 ~ 40 ℃. However, the system has high requirements for the cleanliness and sanitation of the area where it is located. Dust and relative humidity should be controlled during the operation of the equipment. Dust adhesion and humidity will lead to disordered working efficiency of the host, Damage the corresponding equipment components, so in the relevant use scenarios, it is necessary to strictly require the cleanliness and air humidity index. If conditions permit, it can be considered to set temperature controller and heater for the system to cook in time. Due to the high temperature requirements of energy storage battery, the general operating temperature environment is required to be about 25 ℃ and not more than 30 ℃. When the temperature is too low, the capacity of storage battery will be obviously affected, resulting in a decline. According to the relevant data It is estimated that when the ambient temperature drops by one degree centigrade, the storage battery capacity will decrease by 1%. 　
Its discharge capacity increases with the increase of temperature, but it will shorten the service life of the equipment. If it is used at high temperature for a long time, the service life of the battery will be reduced by half when the temperature of the service environment is increased by 10 degrees centigrade, and the reduction range is very large. Therefore, it is necessary to strictly control the temperature of the service environment Degree.
Conclusion
In the use of UI, the maintenance work can not be ignored. No matter how good the equipment is, there will be various failures. The maintenance work should not be ignored because of its high intelligence, maintenance free or imported equipment. Prevention is an important guarantee for safe operation at any time.