SVPWM control method, system and device for eliminating dead zone effect

Abstract

The invention discloses an SVPWM (Space Vector PWM) control method, system and device for eliminating a dead zone effect, which are applied to an NPC multi-level converter. The method comprises the steps of: obtaining three sub-vectors used for synthesizing a target voltage vector, determining the action time proportion of the three sub-vectors and the corresponding switch state thereof, and obtaining an initial comparison value of each phase in three phases according to the action time proportion and the switch state; according to the current direction of each phase in the three phases and the slope of a triangular carrier, correcting the initial comparison value by using a preset correction amount to obtain a corrected comparison value; comparing the corrected comparison value of each phase in the three phases with the triangular carrier to obtain a corresponding comparison result; and logically processing each phase according to the comparison result of each phase to generate the SVPWM pulse. By using the SVPWM pulse obtained by the invention, a relatively ideal sine wave output voltage can be obtained, the total harmonic distortion of the output current is obviously reduced, and the impact on a load or a power supply network is avoided.

Description

technical field [0001] The invention relates to the field of power electronics and electric transmission, in particular to a SVPWM control method, system and device for eliminating the dead zone effect. Background technique [0002] The diode-clamped (Neutral Point Clamped, NPC) three-level topology is very suitable for medium-voltage and high-power industrial converter drives, such as electric locomotive traction, offshore wind power, metallurgical rolling mills, mine hoists, ship propellers, etc., combined with Existing commercial high-voltage and high-power semiconductor devices (such as IGBT, IGCT, TEGT, etc.) can realize the high withstand voltage and strong overcurrent performance of the converter. Space Vector Pulse Width Modulation (Space Vector PWM, SVPWM) has been widely researched and applied in medium-voltage and high-power conversion applications due to its advantages of high DC voltage utilization and good performance in a wide range of modulation ratios. [0...

AI Technical Summary

Problems solved by technology

Due to the existence of the dead zone, the switching device cannot switch in an ideal way, so that the output voltage deviates, resulting in output voltage distortion, and the harmonic content of the output voltage and current is more, causing an impact on the load or power supply network, such as causing the torque of the motor to occur Severe fluctuations or even damage, Total Harmonic Distortion (THD, Total Harmonic Distortion) of the output current does not meet international or domestic grid-connected standards, etc., and the impact of wide dead zone is even worse

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