A new unipolar frequency doubling spwm modulation method for single-phase high-frequency chain matrix rectifier

Abstract

A novel unipolar frequency doubling SPWM modulation method for a single-phase high-frequency chain matrix rectifier. The topology of the single-phase high-frequency chain matrix rectifier is determined by the AC input voltage U s , LC input filter, matrix converter, high-frequency transformer, post-stage uncontrolled diode, L-type filter, load R dc connected sequentially. The modulation method is to compare two positive and negative sinusoidal modulation waves with the same triangular carrier signal, modulate to generate four SPWM waves, and then perform coupling, that is, after "AND" logic synthesis with high-frequency square wave signals Vp and Vn Get eight driving waves, and then perform "or" logic synthesis to get four S ah , S al , S bh , S bl driving wave, that is, S nal and S pah Share a drive signal S ah , S nah and S pal Share a drive signal S al , S nbl and S pbh Share a drive signal S bh , S nbh and S pbl Share a drive signal S bl . The method can solve the problem that the primary voltage peak is generated because the primary current ip has no flow path due to the leakage inductance of the transformer. And it has less switching loss and better output voltage waveform quality.

Description

technical field [0001] The invention relates to the field of modulation and control of power electronic matrix converters, in particular to the modulation method of single-phase current-type high-frequency chain matrix rectifiers. Background technique [0002] The matrix rectifier is evolved from the AC-AC matrix converter. Compared with traditional rectifiers and bidirectional rectifiers, it has a standard sinusoidal input current and can achieve unity power factor on the input side. It does not require large-capacity energy storage elements, only needing A small-capacity filter to filter out high-order harmonics is sufficient on the input and output sides, which has the advantages of small size and light weight. The high-frequency chain rectifier uses high-frequency transformers instead of power-frequency transformers to overcome the shortcomings of traditional transformers such as large volume, large noise, and high cost. The high-frequency chain matrix converter absorbs...

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Problems solved by technology

[0004] However, although the above strategies can achieve safe commutation, the modulation and control of the matrix converter are complicated, and the commutation is unnatural, the switching loss is large, and the quality of the output voltage waveform is poor.

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