High-efficiency inverter

Abstract

The invention relates to a high-efficiency inverter, which is simply structured and suitable for improving the efficiency of the inverter as well as DC electromagnetic interference. The high-efficiency inverter comprises four inverter transistors, two free wheeling transistors, two diodes and two filter inductors. When working, a microcontroller switches a first free wheeling transistor on for a half power frequency cycle, simultaneously switches a first inverter transistor, a fourth inverter transistor and a second free wheeling transistor off, and synchronously switches a second inverter transistor and a third inverter transistor at high frequency under the synchronous triggering of a high frequency triggering signal to make the outside ends of a first filter inductor and a second filter inductor output the positive half cycle of an AC power supply; then the microcontroller switches the second free wheeling transistor on for the half power frequency cycle, simultaneously switches the second inverter transistor, the third inverter transistor and the first free wheeling transistor off, and synchronously switches the first and fourth inverter transistors at the high frequency under the synchronous triggering of the high frequency triggering signal to make the outside ends of the first and second filter inductors output the negative half cycle of the AC power supply; and the operations are repeated.

Description

technical field [0001] The invention relates to the technical field of inverter power supplies, in particular to a high-efficiency inverter. Background technique [0002] The inverter is a power conversion device, which mainly realizes the energy conversion from DC to AC. Grid-connected inverters include photovoltaic grid-connected inverters, wind energy grid-connected inverters, fuel cell grid-connected inverters, etc. The grid-connected inverter can efficiently convert the energy generated by renewable energy into alternating current with the same frequency and phase as the mains, which can be connected to the mains. [0003] Divided according to its circuit form: half-bridge inverter power supply and full-bridge inverter power supply. Among them, there are two control modes of the full-bridge inverter power supply: unipolar PWM modulation and bipolar PWM modulation. Bipolar PWM modulates the complementary drive of the two switch tubes of the same bridge arm. Due to the...

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Problems solved by technology

Bipolar PWM modulates the complementary drive of the two switch tubes of the same bridge arm. Due to the inconsistency of the switch tube conduction and cut-off characteristics and the inconsistency of the control circuit parameters of the dead time, the two switch tubes of the same bridge arm may be turned on at the same time. through, which will lead to damage to the switch tube

Unipolar PWM control has: only one switching tube performs high-frequency switching in the positive and negative half cycles of the mains, resulting in a decrease in the utilization rate of the output inductance, thereby reducing the efficiency of the inverter power supply; at the same time, the DC EMI of this control method (DC electromagnetic interference) problems are also prominent

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