Safe operation of the hottest low voltage reactive

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Safe operation of low-voltage reactive power intelligent compensation device

the low-voltage reactive power intelligent compensation device is an intelligent reactive power automatic compensation controller added to the traditional reactive power compensation device. Because of its intelligence, less maintenance and good follow-up performance, it is unmatched by traditional reactive power compensation devices in many aspects, such as compensating reactive power, improving power factor, saving energy and reducing losses, improving voltage quality, improving equipment output, and then improving enterprise benefits. In recent years, it has also been rapidly developed and widely used

however, the low-voltage reactive power intelligent compensation device also has some problems, such as the imperfect performance of the product itself, the lack of hanging operation experience, the lack of user awareness and so on. In order to make it mature and popularize, the author puts forward solutions to some of its existing problems

1 existing problems of low-voltage reactive power intelligent compensation device

first of all, low-voltage reactive power users are willing to carry out experiments after 1 startup. There are deficiencies in the intelligent compensation device, which affects the compensation effect. Among them, the controller, as the core component, is still in the stage of perfection and gradually moving towards maturity. There is no national standard or industrial standard. Hundreds of manufacturers contend, product grades are uneven, and fake and inferior products flood the market, resulting in misoperation, refusal, and oscillation from time to time. The quality of capacitors and contactors is also not optimistic. For example, low-quality capacitors often leak, deform, or even explode and cause fire accidents. Common faults of fake and inferior contactors include contact burning, mechanism jamming, poor product stability, and obvious lack of electrical and mechanical life

secondly, the user unit does not pay enough attention to reactive power management, lacks basic theoretical knowledge, cannot make corresponding selection according to its own load characteristics, has insufficient understanding of product performance, and the parameter setting is unreasonable, resulting in inaccurate switching time or misoperation of reactive power compensation device. When problems are found, it is difficult to deal with them individually according to specific situations, so that they can not give full play to their benefits

again, the cyclic switching phenomenon of "under switching, over switching, over switching and under switching" occurs from time to time, which not only reduces the effect of reactive power compensation, but also affects the service life of capacitors and contactors, and causes impact on electricity

2 methods to solve existing problems

first, check the design and equipment selection. In the design of the overall scheme, we should pay attention to the progressiveness, practicality and pertinence of the technology, and the harmony and unity of the economy that Domenicali said the car was planned to be launched in 2020 or 2021. With the permission of funds, choose high-tech products as much as possible, and take into account the economy on the basis of a good working environment. Traditional controllers only have cos φ、 Action delay, basic parameter setting of overvoltage setting, concise man-machine dialogue and status indication, easy to use, economical and applicable, suitable for ordinary users with excellent electrical environment and stable load. For the users with large harmonic pollution, they must choose a high-performance controller with strong anti harmonic interference ability. With the rapid development of computer technology, the controller tends to simplify wiring, diversify functions, and judge intelligently, and adds management functions to facilitate users to make reasonable choices according to specific situations. In addition, because the contactor bears the executive function of closing and opening operation in the whole device, try to choose the famous and high-quality products of regular manufacturers. In terms of specific selection, CJ type special contactor for switching capacitor can be used. Compared with the traditional mode, it has the significant advantages of energy saving, material saving, compact structure, small occupied area, simple wiring and stable performance. Capacitors should also be selected from a high starting point in terms of equipment selection. Capacitors with excellent self-healing performance, anti-interference ability, low loss and strong safety (such as built-in protection and self discharge devices) are expected to exceed 9billion by 2050. In the design, pay attention to the harm of high-order harmonics to the capacitor. Harmonics are easy to cause overload, overheating, vibration, abnormal sound and even damage of the capacitor. In order to reduce or avoid the occurrence of the above situations, harmonic suppression measures such as adding harmonic filter devices or series reactors should be taken according to the specific situation of harmonics

secondly, master the performance of the equipment to give full play to its benefits. At the beginning of equipment operation, you must read the equipment installation and operation manual in detail to understand and master its performance, characteristics, functions, scope of application and precautions. In the operation of the device, actively respond to the new situation after changes and solve new problems. If the load changes violently, in order to reduce the frequent action of the contactor, adjust the cos appropriately φ Lower limit setting, and appropriately increase the action delay. In the places where reactive load changes rapidly, with large amplitude and frequent stop and conversion, the traditional circular working mode of "equal capacity grouping configuration, first input, first stop, first input" is adopted, which is now a popular material. It is difficult to take into account the tracking speed and the service life of the device, and the compensation effect is not good; If the working mode of "differential capacity grouping, automatic capacity identification and on-demand switching off" is adopted, it has the advantages of rapid startup, short tracking time, relatively low action frequency and good compensation effect

in addition, solve the oscillation phenomenon. In order to avoid this phenomenon, on the one hand, it is necessary to reasonably configure the distribution and transformation capacity to avoid the big horse pulling the small car; On the other hand, the number of capacitor groups of large capacity distribution transformer should be appropriately increased. In addition, certain effects can also be achieved by adjusting the threshold and action time limit of the controller

to sum up, compared with traditional compensation devices, low-voltage intelligent reactive power compensation devices are progressiveness in technology because of their intelligence and good follow-up; But at the same time, it must be admitted that this technology is not mature and standardized. Users should strengthen their own quality, choose products suitable for their own characteristics, constantly accumulate in practice, face problems with a scientific and pragmatic attitude, take practical measures according to local conditions, jointly promote the improvement and promotion of low-voltage intelligent reactive power compensation devices, and do a good job in reactive power management

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