Novel voltage stabilizer filtering topology and filtering control method

Abstract

The invention provides an AC chopper-type voltage stabilizer, a filtering method and a filtering system thereof. The voltage stabilizer comprises a two-way switch buck converter, a filter circuit, a transformer and a control unit, wherein the control unit treats the actual input voltage Vm of the voltage stabilizer according to the following filtering method, generates and sends control signals to the two-way switch buck converter, and controls the output waveform of the voltage stabilizer by controlling the turn-on and turn-off of a power switching element. The filtering method at least comprises: (1) performing band-stop filtering on the actual input voltage Vm of the voltage stabilizer and generating a signal Vs1; (2) implementing linear correction and generating a signal Vs2; (3) performing division algorithm and generating a signal Vc; (4) performing negative feedback operation and generating a signal Vs3; and (5) forming a PWM control signal. Through hardware and software filtering, the invention has the advantages of improving filter topology, adding a filtering control method and ensuring good voltage waveform on the primary side of the transformer, good voltage compensation effect of the transformer and superior performance of the voltage stabilizer.

Description

technical field [0001] The invention belongs to the filter technology for eliminating the harmonic generated by the voltage stabilizer in the electric power system, in particular to an AC chopper type voltage stabilizer and its filtering method and filtering system. Background technique [0002] Usually, high-power regulators have very high requirements on the output voltage, not only to ensure phase and amplitude stability, but also to have a good output waveform. The main working component of the voltage stabilizer - the AC chopper circuit will generate a large amount of harmonics during the working process, and the nonlinear load will also generate a large amount of harmonic current. These large number of harmonics will not only cause damage to the output device, but also cause the instability of the voltage regulator system. [0003] At present, ordinary LC filters are mostly used to filter out high-order harmonics. The circuit structure is as follows: figure 1 shown. ...

AI Technical Summary

Problems solved by technology

[0011] Furthermore, from the sources of harmonics in the voltage regulator, it can be seen that some harmonics are generated due to the nonlinearity of the load, and the traditional filter circuit cannot eliminate the nonlinear harmonics of the load

This part of harmonic current will be transmitted to the primary side of the transformer through the secondary side of the transformer, and harmonic voltage will be generated at the output of the filter, which will affect the compensation effect of the transformer

In addition, since the values ​​of capacitance and inductance in the traditional filter circuit will not change once the design is determined, and are limited by the topology of the filter circuit, the signal filtering effect for specific frequencies is poor

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