Reactive compensation and current zero-crossing distortion free modulation method of single-phase grid connected inverter

Abstract

The invention relates to a modulation method for realizing reactive compensation and nondistortion of the grid connected current at the power grid voltage zero crossing point and the zero crossing point itself based on a single-phase grid connected system. The modulation method includes six controlled switch tubes S1-S6 of an H6 bridge inverter circuit, a negative free-wheeling diode D1, and a positive free-wheeling diode D2, and the function of reactive compensation is achieved through the different driving control of the controlled switch tubes at different times, and the power grid current is free of waveform distortion at the power grid voltage zero crossing point and the zero crossing point of itself.

Description

technical field [0001] The single-phase inverter grid-connected circuit of the present invention particularly relates to a method with reactive power compensation and no zero-crossing distortion of current. [0002] Background technique: [0003] Energy crisis, atmospheric pollution and global warming are the biggest problems facing mankind. These two problems are inseparable from the fact that today's world still relies on fossil energy as the main energy consumption. To this end, we need to develop and utilize clean and renewable energy. Solar energy is a clean, almost inexhaustible source of energy. [0004] Among them, photovoltaic power generation is one of the main ways to utilize solar energy, and has been supported and developed by the society and the state. In addition, the rise of the global energy Internet has higher technical requirements for the operation of distributed photovoltaic grid-connected power generation on the distribution network. The new standard r...

AI Technical Summary

Problems solved by technology

The current modulation method of driving waveform can often achieve reactive power compensation, but the grid-connected current will be distorted at the grid voltage and its own zero-crossing point, because the grid voltage and grid-connected current or reference voltage and grid-connected current are used for time segments Or the zero point of the grid voltage and reference current is used as the division wiring, which will cause distortion of the grid-connected current at the zero-crossing point of the grid current and its own zero-crossing point, so the present invention designs a single-phase photovoltaic grid-connected inverter that is both It can output reactive power and ensure no current zero-crossing distortion, and the control algorithm is simple and easy to implement

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