Grid high-frequency impedance remodeling device and method for suppressing distributed generation resonance

Abstract

The invention relates to a grid high-frequency impedance remodeling device for suppressing distributed generation resonance. The remodeling device is composed of a power grid-connected converter and aresonant impedance controller. The resonant impedance controller consists of a resonant detection module and a resonant current tracking module. The resonant detection module detects the voltage upccof a PCC point by a voltage sensor; predetermined circuit processing is carried out on the voltage upcc to obtain resonant voltage components upccr<+> and upccr< > and a resonant frequency omega r; and predetermined circuit processing is carried out on the resonant voltage components upccr<+> and upccr< >, the resonant frequency omega r, the voltage upcc of the PCC point, and a direct-current voltage Udc by the resonant current tracking module to obtain a PWM pulse signal for controlling connection or disconnection of a switching tube of a power grid-connected converter. According to the invention, the grid high-frequency impedance remodeling device is installed at the PCC point and detects the resonant voltage components of the PCC point; the resonant impedance controller including equivalent damping resistance information is used for obtaining a current instruction outputted by the converter; the converter is controlled to track the instruction value; and a virtual variable harmonicimpedance is generated to realize grid harmonic suppression.

Description

technical field [0001] The invention relates to the technical field of distributed generation harmonic control, in particular to a power grid high-frequency impedance reshaping device and method for suppressing distributed generation resonance. Background technique [0002] As the global energy crisis and environmental pollution become increasingly prominent, renewable energy power generation represented by photovoltaic power generation, wind power generation and hydropower generation is developing rapidly and will surely occupy an important position in the future energy composition. In view of the distribution characteristics of possible renewable energy dispersal and randomness, the most ideal choice at present is to adopt distributed generation (DG) technology. DG mainly uses the renewable energy around the load to realize the nearby consumption of electricity, and has many advantages such as less power transmission loss, energy security, environmental friendliness, and l...

AI Technical Summary

Problems solved by technology

In practical applications, the existence of grid impedance causes coupling between inverters, and the resulting resonant network is more complex. If effective suppression measures are not taken, it may cause faultless tripping of grid-connected inverters, or even Further cause cascading failures, thus affecting the power quality and stable operation of the distribution network

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