13-segment carrier pulse width modulation method and system and related components

Abstract

The invention discloses a thirteen-segment carrier pulse width modulation method and system and related components, relates to the field of carrier pulse width modulation, is applied to a three-level converter, and comprises the following steps: sorting three instantaneous voltage values of a three-phase sine wave; according to the maximum voltage value, the intermediate voltage value and the minimum voltage value, determining a dual-modulation wave parameter of the corresponding phase; determining an upper modulation wave and a lower modulation wave of the corresponding phase according to the dual modulation wave parameter of each phase; and comparing the upper modulation wave, the lower modulation wave and the triangular carrier wave of each phase to generate a driving signal of the corresponding phase. The driving signal output by the modulation method can ensure that the phase voltage pulse width of a low modulation degree region is greater than the minimum switching time of a device, so that narrow pulses are effectively eliminated, the target voltage is accurately output, and the effects of reducing current harmonic distortion and improving neutral-point voltage self-balance of the three-level converter are achieved. In addition, only amplitude calculation is needed, and the method has the advantages of being simple in calculation and easy to implement.

Description

technical field [0001] The invention relates to the field of carrier pulse width modulation, in particular to a thirteen-segment carrier pulse width modulation method, system and related components. Background technique [0002] Due to the advantages of low voltage stress of power devices, good output power quality, and relatively simple structure and control, three-level neutral point clamped (NPC) converters, referred to as three-level converters, are used in grid reactive power. Compensation, rail transit, wind power generation, metallurgical mining and other fields have been widely used. figure 1 It is the main circuit topology of the three-level converter. [0003] The control core of the three-level converter is to control the switching state of each power device. When each power device switches according to the set driving signal, the three-level converter can output the set voltage vector, and then accurately output the target. When the power devices are not driven...

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Problems solved by technology

[0003] The control core of the three-level converter is to control the switching state of each power device. When each power device switches according to the set driving signal, the three-level converter can output the set voltage vector, and then accurately output the target. voltage, and when the power devices are not driven normally, the output voltage of the three-level converter will be distorted, and even the operation of...

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