Harmonic cancellation and power compensating device

Abstract

This invention relates to a device for eliminating harmonic waves and compensating power, in which, a filter is composed of overlapped silicon-steel sheets and copper sheet windings, coils of three copper windings are the same relating to the power and controlled current, the entrance of the windings is connected with the net by switch, after absorbing harmonic waves, the output end of the filter is connected with multiple AC contactors and capacitors by multiple switch sets and the capacitor charges and discharges in terms of 50Hz, namely, harmonic waves are eliminated in the net after the higher-order harmonic waves pass through the filter, current without harmonic waves comes back to the net after being compensated reactively by the capacitor.

Description

technical field [0001] The invention belongs to a harmonic elimination and power compensation device. Background technique [0002] As we all know, with the advancement of science and technology and the rapid development of electric power, especially electric locomotives, rectifier equipment, electric furnaces and other loads in metallurgy, chemical industry, mining, electrified railways and DC transmission, as well as color TVs and fluorescent lamps in the field of household appliances The extensive use of electrical equipment and the widespread application of switching power supplies, high-frequency power supplies, intermediate-frequency power supplies, and electronic ballasts in the electronics industry have caused a large number of high-order harmonics to be injected into the power grid, resulting in sine wave distortion and a serious decline in power quality. Not only will it have a major impact on the main equipment of the power system, but it will also cause serious h...

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Problems solved by technology

[0002] As we all know, with the advancement of science and technology and the rapid development of electric power, especially electric locomotives, rectifier equipment, electric furnaces and other loads in metallurgy, chemical industry, mining, electrified railways and DC transmission, as well as color TVs and fluorescent lamps in the field of household appliances The extensive use of electrical equipment and the widespread application of switching power supplies, high-frequency power supplies, intermediate-frequency power supplies, and electronic ballasts in the electronics industry have caused a large number of high-order harmonics to be injected into the power grid, resulting in sine wave distortion and a serious decline in power quality. Not only will it have a major impact on the main equipment of the power system, but it will also cause serious harm to the majority of users. The problems of high-order harmonic harm and reactive power shortage in this kind of power grid are becoming more and more serious, and the harm caused is becoming more and more serious. The excessive subharmonic exceeds the standard, the surge impact is frequent, and the system voltage jumps instantaneously, causing the peak voltage to be too high, threatening the insulation safety of electrical equipment, and causing failure; eddy currents are generated, and the damping effect causes local overheating of electrical equipment and excessive noise , the additional power is increased, which increases the consumption of electric energy

At present, the method of eliminating harmonics and power compensation is to connect capacitors in parallel in the power supply system, take advantage of the characteristics that the terminal voltage of capacitors cannot be abruptly changed, and connect reactors in series with each capacitor to reduce the impact of harmonics on the system, but to reduce The distortion rate of the total voltage waveform has little effect, and will cause additional power loss. Moreover, each capacitor needs a reactor. A total of 16,000 yuan for a reactor, and the installation is cumbersome, and the manufacturing cost is also high; another is to install an isolation transformer, which is troublesome to wind. At the same time, a separate transformer is 35,000 yuan, which is large in size and high in cost

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