Method and device for generating PWM (Pulse-Width Modulation) pulse of multilevel inverter

Abstract

The invention provides a method and a device for generating PWM pulse of a multilevel inverter. The high-frequency complementary characteristic of the switch tubes of a three-phase multilevel inverter is utilized. The method comprises the following steps: utilizing three PWM peripheral units in a DSP (Digital Signal Processor) control unit to output PWM high-frequency signals; determining the two complementary high-frequency switch tubes in the phase at present according to the current state of detected level signals output by GPIO (General Purpose Input / Output) interfaces with a preset amount, distributing the PWM high-frequency signals to one of the switch tubes to be processed and sending to the other of the switch tubes to be processed after negation of the PWM high-frequency signals through a detection control unit; meanwhile, keeping the states of other switch tubes unchanged according to preset corresponding relations of the states of the switch tubes of the multilevel converter in different switching periods and output level. Therefore, compared with the prior art, the amount of the PWM pulse output DSP peripheral units of the multilevel inverter is reduced, and the difficulty in expanding level number of the inverter is greatly reduced.

Description

technical field [0001] The invention mainly relates to the technical field of pulse width modulation, and more specifically relates to a method and device for generating PWM pulses of a multilevel inverter. Background technique [0002] In recent years, with the rapid development of new energy and distributed power generation technologies, multi-level inverters, especially three-level inverters and five-level inverters, have been widely used. In practical applications, pulse width Pulse-Width Modulation (PWM) technology realizes multi-level inverter control, in which, the more levels of the inverter, the more PWM pulse output is required, and the corresponding PWM pulse wave sending method is also more complicated. [0003] In the prior art, usually the PWM peripheral unit in the DSP (Digital Signal Processing, digital signal processing) chip of the C2000 series is used alone to realize the increase and decrease comparison of the duty cycle and the triangular carrier to out...

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Problems solved by technology

[0006] In view of this, the present invention provides a multi-level inverter PWM pulse generation method and device, which solves the problem of shortage of DSP peripheral units for realizing multi-level inverter PWM pulse output in the prior art

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