Space vector pulse width modulation (SVPWM) and fuzzy proportion integral (PI)-based grid-connected control method of Z-source inverter

Abstract

The invention relates to a space vector pulse width modulation (SVPWM) and fuzzy proportion integral (PI)-based grid-connected control method of a Z-source inverter. An equivalent space rotation voltage vector is synthesized by selecting two adjacent effective vectors in the same section, an appropriate traditional zero vector and a direct-connection zero vector, the action times of the effective vectors are the same as that of a traditional voltage type inverter, and a part or all of action times of the traditional zero vector are substituted by direct-connection zero vectors. The SVPWM-based grid-connected inverter has the characteristics of high DC voltage utilization ratio, low harmonic distortion rate of a power grid current and no floating control, and decoupling control of direct-axis and quadrature-axis currents can be achieved; and a large output voltage range of the Z-source inverter, low harmonic distortion rate of the SVPWM grid-connection current and the advantage that a PI parameter can be adjusted on line by the fuzzy PI controller with regard to an error size are integrated, so that the system has the advantages of high control accuracy, good dynamic and static performance, high grid-connected power factor, high reliability and the like.

Description

technical field [0001] The invention relates to a power grid-connected control technology, in particular to a Z-source inverter grid-connected control method based on SVPWM and fuzzy PI. Background technique [0002] With the increasingly serious energy crisis, the development and utilization of new energy technology has become a hot spot in the development of science and technology in the world today. In the utilization of new energy, the grid-connected inverter is very important. The traditional voltage-type inverter is actually a step-down inverter. When the output voltage is required to be greater than the input voltage and the voltage changes greatly, it is usually necessary to add a DC-DC boost circuit in the front of the inverter, so that the system volume is reduced. Costs increase, but efficiency decreases. In addition, the upper and lower switching tubes of the same bridge arm of the traditional voltage-type inverter cannot be turned on at the same time, otherwis...

AI Technical Summary

Problems solved by technology

The traditional voltage-type inverter is actually a step-down inverter. When the output voltage is required to be greater than the input voltage and the voltage changes greatly, it is usually necessary to add a DC-DC boost circuit in the front of the inverter, so that the system volume is reduced. Costs increase, but efficiency decreases

In addition, the upper and lower switching tubes of the same bridge arm of the traditional voltage-type inverter cannot be turned on at the same time, otherwise a short circuit will be formed and the device will be burned. Therefore, the corresponding dead time must be added, but the addition of the dead time will cause output waveform distortion and affect grid connection. Stability of operation

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