A Signal Processing Method for Reducing Current Distortion of Photovoltaic Inverter

Abstract

The invention discloses a signal processing method for reducing current distortion of photovoltaic inverters. The signal processing method is characterized by comprising steps of (1), converting voltage signals of power grids by voltage sensors, and then converting the analog signals into digital signals by A / D (analog / digital) sampling modules; (2), transmitting the digital signals to IIR (infinite impulse response) digital filter modules, digitally filtering the digital signals and then outputting sine wave signals; (3), transmitting the sine wave signals to digital shaping modules and outputting square wave signals after the sine wave signals are converted; (4), inputting the square wave signals into phase angle computing modules and computing phase angles of the voltages of the power grids; (5), converting the phase angles outputted by the phase angle computing modules and outputting PWM (pulse width modulation) control signals. The signal processing method for reducing the current distortion of the photovoltaic inverters has the advantages that the problem of high harmonic contents in grid-connected currents of existing photovoltaic inverters due to severe grid-side voltage distortion can be solved by the aid of the signal processing method, and the signal processing method is favorable for improving the quality of grid-connected currents of the grid-connected inverters.

Description

technical field [0001] The invention belongs to the technical field of power electronic control, and in particular relates to a signal processing method for reducing current distortion of a photovoltaic inverter. Background technique [0002] Photovoltaic grid-connected power generation technology has become an important direction of new energy utilization. Grid-connected inverters are the core components of photovoltaic systems, so high-quality inverter power supplies have become the focus of research. [0003] In the photovoltaic grid-connected system, it is an essential link to accurately and quickly detect the frequency, phase and amplitude of the grid voltage. When the grid voltage is severely distorted, the output current of the inverter is prone to distortion problems such as zero crossing, peak, and trough, which affect the power quality of the grid. To solve this problem, the traditional method is to use a digital phase-locked loop to detect the zero-crossing point...

AI Technical Summary

Problems solved by technology

[0004] In order to solve the problem in the prior art that the grid-connected current of photovoltaic inverters has a large harmonic content caused by serious grid-side voltage distortion, the present invention provides a grid-connected current that is beneficial to provide grid-connected inverters. Quality reduction photovoltaic inverter current distortion signal processing method

Images