Inverter

Abstract

The invention relates to an inverter which comprises a circuit system and a control system. The circuit system comprises a solar cell panel and a power grid output. A direct current switch, a BOOST boosted circuit, a single phase full bridge circuit and a grid-tied filter are sequentially arranged between the solar cell panel and the power grid output. The control system comprises a digital signal processor (DSP) control platform, the DSP control platform is connected with a protection module, a sampling and conditioning module, a passage zero comparison module and a level switch module, and the level switch module is connected with an input / output (I / O) information module, a driving module and a power amplifier module. The inverter has the advantages of being based on the DSP control platform, using modes of topology, modulation and the like, and having high efficiency, light weight, small size and the like in actual use. The highest efficiency reaches to 97.51%. Simultaneously, the inverter can control and track grid-tied voltage phase without dead beat, and achieves unity power factor grid-tied. Grid-tied current has good harmonic characteristics, and full load total harmonic distortion (THD) is 1.57%.

Description

technical field [0001] The present invention relates to the field of electronic technology, in particular to an inverter. Background technique [0002] With the continuous development of photovoltaic technology, grid-connected power quality and efficiency, the two most important indicators of photovoltaic grid-connected inverters, have become the current technical difficulties and priorities. The inverters on the market are mainly divided into two types: isolated and non-isolated photovoltaic inverters. The isolated inverter contains a transformer so that there is no direct electrical connection between the battery panel and the grid, ensuring the safety of users. , but the transformer brings efficiency loss. Generally, the efficiency of isolated inverters is 1.5% or more lower than that of non-isolated inverters, so non-isolated inverters will be the mainstream in the future market. [0003] There are two ways for non-isolated photovoltaic inverters to solve the problem of...

AI Technical Summary

Problems solved by technology

[0004] Although these technologies can solve the problem of common-mode leakage current to ground, both methods 1 and 2 need to add a new power switch tube on the basis of the full bridge, which increases the difficulty of main circuit design and control. At the same time, the new switch The tubes work at high frequency, which increases the loss to a certain extent and compromises the efficiency advantage brought by unipolar modulation.

The disadvantage of method 3 is that the DC voltage input requirement is twice that of the H-bridge, and the DC utilization rate is low. It is necessary to increase the voltage value of the bus, which increases the DC bus capacitance and the withstand voltage requirements of the pre-stage booster circuit.

Images