A single-stage single-phase current source inverter with energy storage inductance connected in parallel with active snubber circuit

Abstract

The invention relates to the technical field of power electronics, in particular to a single-stage single-phase current-mode inverter with an energy storage inductor parallel with an active buffer circuit. The single-stage single-phase current-mode inverter comprises the energy storage inductor, a single-phase inverter bridge and an output filter which are cascaded in turn. The two ends of the energy storage inductor are connected in parallel with the active buffer circuit. The active buffer circuit comprises a buffer capacitor, two diodes and two fully controlled power switches. The single-phase inverter bridge is mainly composed of four fully controlled power switches. The inverter can convert unstable, low-amplitude and poor-quality direct current into stable, high-amplitude and high-quality single-phase output sinusoidal alternating current and is suitable for single-phase passive and grid-connected inversion occasions with boosted voltage and small and medium capacity.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to a single-stage single-phase current-type inverter in which an energy storage inductor is connected in parallel with an active snubber circuit. Background technique [0002] The inverter is a static conversion device that uses power semiconductor devices to convert direct current into alternating current, which is used for AC loads or connected to the public grid for power generation. [0003] Due to the increasing shortage of fossil energy (non-renewable energy) such as oil, coal and natural gas, serious environmental pollution, global warming, nuclear energy production will produce nuclear waste and pollute the environment, energy and the environment have become major issues facing mankind in the 21st century . Renewable energy (green energy) such as solar energy, wind energy, tidal energy and geothermal energy has the advantages of being clean, pollution-free, cheap,...

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Problems solved by technology

When this type of inverter works normally, the DC side voltage must be greater than the peak value of the AC side phase voltage, so there is an obvious defect: when the DC side voltage (such as the output capacity of photovoltaic cells) decreases, such as rainy days or nights, the entire power generation The system will stop functioning and the utilization of the system will drop

In this regard, the following two methods are often used to solve this problem: (1) Add a Boost DC converter to the front stage to form a two-stage power conversion circuit structure, which increases the complexity, loss and cost of the circuit; (2) ) output plus a single-phase power frequency transformer, which greatly increases the volume, weight and cost of the system, especially difficult to adapt to today's sharp rise in the price of copper and iron raw materials

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