Method for restraining voltage background harmonic wave of grid-connected inverter

Abstract

The invention discloses a method for restraining a voltage background harmonic wave of a grid-connected inverter. The method adopts a direct-current source, an IGBT (Insulated Gate Bipolar Transistor) intelligent power module and an LCL (Lower Control Limit) type filter, wherein the direct-current source is subjected to a single-phase inversion output through the IGBT intelligent power module; and the single-phase inversion output is accessed to a power grid after being accessed with the LCL type filter. The method disclosed by the invention is characterized by comprising the following steps of: multiplying a sampling voltage signal of the power grid with a reference current amplitude I* after carrying out PLL (Phase Locking Loop) phase locking, so as to obtain a reference current signal; carrying out closed-loop adjustment on the reference current signal and a feedback current iL2 so as to obtain a first path of signals; multiplying the sampling voltage signal of the power grid with a feed-forward function so as to obtain a second path of signals; multiplying a capacitive current signal led by a capacitive branch of the LCL type filter with a virtual resistance function so as to obtain a third path of signals; and combining the first path of the signals, the second path of the signals and the third paths of the signals and then sending the combined signals to Ginv(s) for modulation so as to generate a PWM (Pulse Width Modulation) gate pole drive signal; and triggering a switching tube of the IGBT intelligent power module to be switched on or off by the PWM gate pole drive signal. With the adoption of the method disclosed by the invention, the influence of the background harmonic wave of the power grid can be effectively removed.

Description

technical field [0001] The invention belongs to the technical field of grid-connected inverter control, and in particular relates to a method for suppressing voltage background harmonics of a grid-connected inverter. Background technique [0002] In recent years, the energy crisis has become increasingly tense, and environmental pollution caused by fossil energy consumption continues. Finding active and effective countermeasures to solve the energy crisis and environmental pollution problems has become one of the hotspots at home and abroad. As a better way to supplement energy, distributed power generation based on renewable energy has been rapidly developed and popularized. With the continuous development of grid-connected power generation technology, the grid-connected power generation of distributed power generation systems has become the main trend of electric energy applications. Therefore, it is particularly critical to study grid-connected inverters with low loss, ...

AI Technical Summary

Problems solved by technology

[0005] The invention provides a method for suppressing the voltage background harmonics of a grid-connected inverter, and solves the loss and heat dissipation problems caused by the passive damping method

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