Reactive power compensation and harmonic treatment system

Abstract

The invention discloses a reactive power compensation and harmonic treatment system. The system comprises a reactive power compensation and harmonic treatment device which comprises voltage current transformers which are respectively connected to a power grid and are used for converting grid voltage into standard secondary voltage and secondary current to be used by an instrument control device, a second-order filtering loop which comprises a non-inductive resistor and a filtering reactor which are in parallel connection and is in series connection with the output end of the current transformer, a plurality of capacitor filtering branches which comprise a plurality of filtering capacitor groups, wherein one end of each of the filtering capacitor groups is connected with the second order filtering loop through the respectively corresponding breakers, and the other end of each of the filtering capacitor groups is connected with a power grid neutral point, and a detection control device which controls the switching of the connection and disconnection of the corresponding circuit breaker according to the collected power grid parameter values to control the number of the invested filtering capacitor groups. The system has the advantages of small floor space, filtering cutoff frequency does not change along with the change of a load, and harmonics are effectively eliminated.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to a reactive power compensation harmonic control system in a power system. Background technique [0002] With the rapid development of power electronic technology, various power electronic devices have been widely used in power systems, electrified railways, coal mines, non-ferrous metals and other fields, making the harmonic pollution of power grids more and more serious. At the same time, these devices will also generate a large amount of reactive power, making the power factor of the grid low. Harmonics in the power grid reduce the efficiency of production, transmission and utilization of electric energy, reduce the service life of electrical equipment, interfere with communication, etc.; reactive power in the power grid will increase equipment capacity, increase line loss, and increase line voltage drop. Therefore, in order to ensure the power supply quality of the p...

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Problems solved by technology

However, in this mode, the inductance value of the filter reactor is fixed, and it is only suitable for operation under full load.

When the load is small, capacitors cannot be switched in groups, and there will be a problem of input overcompensation

[0007] Therefore, it is necessary to provide a new solution for reactive power compensation and harmonic control to overcome the shortcomings of existing solutions that cannot automatically adjust filter parameters according to load changes and cause limitations in operation.

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