Simplified two-level SVPWM (Space Vector Pulse Width Modulation) algorithm and dead zone compensation method

Abstract

The invention provides a simplified two-level SVPWM (space vector pulse width modulation) algorithm and a dead-zone compensation method, and the method comprises the steps: deducing an SVPWM modulation implicit function according to an SPWM modulation implicit function according to the characteristic that an SPWM modulation mode is similar to an SVPWM modulation mode, and decomposing the SVPWM modulation implicit function to obtain a simplified SVPWM algorithm; the switching time of the SVPWM is calculated by directly utilizing the instantaneous value of the three-phase reference voltage, so that a complex intermediate calculation process is omitted, and the calculation resource of a chip is saved; according to the method, a strategy of performing dead-zone compensation by adopting the power factor angle is adopted, and dead-zone compensation is performed by calculating the power factor angle and predicting the next current vector direction, so that the problem of reverse dead-zone compensation caused by difficulty in direct measurement due to the fact that the output current of the three-phase current zero crossing point contains a large number of harmonic waves is avoided, and the stability of the system is ensured.

Description

technical field [0001] The invention belongs to the technical field of space vector pulse width modulation, in particular to a simplified two-level SVPWM modulation algorithm and a dead zone compensation method. Background technique [0002] SVPWM (Space Vector Pulse Width Modulation) modulation technology has been widely used because of its excellent characteristics such as small current harmonics, high modulation ratio, and wide linear region. The traditional SVPWM modulation technology has complex algorithms and a large amount of calculations due to complex coordinate transformation, sector judgment, unit voltage vector action time, and trigonometric function calculations. In addition, during the SVPWM modulation process, in order to avoid the short circuit of the upper and lower power modules of the same bridge arm during the switching process, the software needs to set a dead time, but the existence of the dead time will cause the output voltage waveform to be distorted...

AI Technical Summary

Problems solved by technology

The traditional SVPWM modulation technology has complex algorithms and a large amount of calculations due to complex coordinate transformation, sector judgment, unit voltage vector action time, and trigonometric function calculations.

In addition, during the SVPWM modulation process, in order to avoid the short circuit of the upper and lower power modules of the same bridge arm during the switching process, the software needs to set a dead time, but the existence of the dead time will cause the output voltage waveform to be distorted and increase the harmonic output of the inverter.

The current dead zone compensation method mainly compensates the duty cycle according to the positive and negative phase currents, but because the output current harmonics are large, it is difficult to obtain the zero point accurately, which leads to reverse compensation and system instability.

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