Current tracking control method of lcl type pwm rectifier in unbalanced power grid

Abstract

The disclosure provides a current tracking control method of an LCL PWM rectifier under an unbalanced power grid, which belongs to the technical field of power electronics-grid-connected converter control; the converter side inductance reference is calculated by using the voltage delay signal in the static coordinate system Current, indirectly tracking the grid-connected current; no current or power compensation, no phase-locked loop and voltage and current positive and negative sequence decomposition, to achieve the basic goal of DC voltage stability and unit power factor, while ensuring the sinusoidal grid-connected current, improving It improves the current quality and reduces the calculation load of the CPU, which is of great significance to the digital control of the rectifier.

Description

Technical field

[0001] The present disclosure relates to the field of power electronics - grid-connected converter control technology, in particular to a current tracking control method of LCL type PWM rectifier under unbalanced power grid. Background

[0002] The statements in this section merely provide background technology related to this disclosure and do not necessarily constitute prior art.

[0003] Compared with traditional L-type filters, LCL filters are widely used in grid-connected PWM rectifiers due to their small size and good high-frequency rejection effect. However, filter capacitors introduce delays between the grid and the converter, increasing the complexity of directly controlling the grid-connected current and power. In addition, the inherent resonant frequency present in the LCL filter increases the harmonic content of the grid-tied current and must be suppressed by appropriate methods.

[0004] The inventors found that in the case of unbalanced grid voltage,...

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