Buck-boost grid-connected inverter and control method thereof

Abstract

The invention discloses a buck-boost grid-connected inverter and a control method thereof, belonging to an inverter and a control method thereof. The inverter comprises a power supply, a common circuit, a first bridge arm circuit, a second bridge arm circuit, a first filter inductor and a second filter inductor. The method comprises the following steps: when the setting of an inductive current is less than zero, a first power switching pipe driving signal and a fifth power switching pipe driving signal complement a high-frequency switch, and a second power switching pipe driving signal and a sixth power switching pipe driving signal are switched off; when the setting of an inductive current is more than zero, the second power switching pipe driving signal and the sixth power switching pipe driving signal complement the high-frequency switch, and the first power switching pipe driving signal and the fifth power switching pipe driving signal are switched off; and a third power switching pipe driving signal is the or logic of the second power switching pipe driving signal and the fifth power switching pipe driving signal, and a fourth power switching pipe driving signal is the or logic of the first power switching pipe driving signal and the sixth power switching pipe driving signal.

Description

technical field [0001] The buck-boost grid-connected inverter and its control method of the present invention belong to the inverter and its control method. Background technique [0002] In recent years, with the increasing environmental pollution and the continuous shortage of fossil energy, renewable energy has attracted more and more attention due to its advantages of cleanness, safety, pollution-free, and renewable. However, the output of solar cells and fuel cells is direct current, while the grid voltage is alternating current. Therefore, grid-connected inverters have become an important part of distributed power generation systems. And because the output voltage range of solar cells and fuel cells is wide, sometimes it is lower than the grid voltage, sometimes it is higher than the grid voltage. Therefore, it cannot be realized by using a traditional single-stage step-down inverter, and it is usually necessary to add a pre-stage DC -DC converter, which increases the ...

AI Technical Summary

Problems solved by technology

And because the output voltage range of solar cells and fuel cells is wide, sometimes it is lower than the grid voltage, sometimes it is higher than the grid voltage. Therefore, it cannot be realized by using a traditional single-stage step-down inverter, and it is usually necessary to add a pre-stage DC -DC converter, which increases the complexity of the system, reduces the reliability and increases the cost of the system

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