A pwm pulse wave releasing method and controller for a three-level inverter

Abstract

The invention provides a three-level inverter PWM pulse wave opening method and a controller. After wave blocking is carried out through an error event forcing function in first priority driving, PWM pulses are firstly forced to be ideal driving signals at wave opening time through a software forcing function in second priority driving; when the current state is judged to meet the wave opening condition in a received wave opening instruction, forcing functions for the first priority driving and the second priority driving are eliminated; and PWM pulses of a single-phase bridge arm control each switch transistor according to the above ideal driving signals, situations of narrow pulses and simultaneous conduction of an inner transistor and an outer transistor are avoided, and the problems that normal, reliable and stable operation of the inverter cannot be ensured can be further avoided.

Description

technical field [0001] The invention relates to the technical field of three-level inverters, in particular to a method for releasing PWM pulses of a three-level inverter and a controller. Background technique [0002] The three-phase three-level inverter system has the advantages of low voltage stress, low output harmonics, etc., and can obtain higher output voltage, so it is widely used in new energy power supply fields such as solar energy and wind energy. figure 1 It is a circuit diagram of a single-phase bridge arm of a three-phase three-level inverter system, including four switch tubes (S1, S2, S3 and S4). The system generally adopts the three-level carrier PWM control method, such as the in-phase carrier SPWM control method, through the single-phase modulation wave u s (optimized decomposition into u s1 and u s2 ) and triangular carrier u c After comparison, PWM pulses (PWM1, PWM2, PWM3 and PWM4) are output. For the corresponding signal waveform diagram, see fi...

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Problems solved by technology

[0005] In view of this, the present invention provides a method and controller for PWM pulse emission of a three-level inverter to solve abnormalities such as narrow pulses in PWM emission and simultaneous conduction of the inner tube and the outer tube in the prior art. Working status, resulting in the failure to guarantee the normal, reliable and stable operation of the inverter

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