CN114421795A

CN114421795A - Single-stage boosting inverter circuit, control method and power supply conversion device

Info

Publication number: CN114421795A
Application number: CN202011173105.9A
Authority: CN
Inventors: 胡茂; 裴轶; 朱永生
Original assignee: Gpower Semiconductor Inc
Current assignee: Gpower Semiconductor Inc
Priority date: 2020-10-28
Filing date: 2020-10-28
Publication date: 2022-04-29

Abstract

The application relates to a single-stage boosting inverter circuit, a control method and a power conversion device, wherein the circuit comprises: the system comprises an input inverter bridge module, an output inverter bridge module, a capacitive energy storage unit and a inductive energy storage anti-reflux unit, wherein the capacitive energy storage unit is respectively connected with the input inverter bridge module, a positive output end of a direct current power supply, a negative output end of the direct current power supply and the ground; the inductive energy storage anti-reflux unit is connected in series between the input inverter bridge module and the output inverter bridge module; the inductive energy storage anti-reflux unit outputs preset boosting alternating current to a next-stage load by respectively controlling the input inverter bridge module and the output inverter bridge module to act cooperatively.

Description

Single-stage boosting inverter circuit, control method and power supply conversion device

Technical Field

The invention relates to the technical field of power electronics, in particular to a single-stage boosting inverter circuit, a control method and a power conversion device.

Background

In the new energy power generation technology, direct current is generally generated firstly, and then the direct current is converted into alternating current by using an inverter so as to be used for grid connection. In order to adapt to the characteristic of wide output voltage range of a power supply in new energy power generation, an inverter device generally needs to have a voltage boosting function, while a traditional voltage type inverter only has the capacity of voltage reduction and inversion, and a two-stage or multi-stage power supply conversion device needs to be adopted.

In addition, with the continuous improvement of the switching frequency of the power semiconductor device, in a non-isolated power supply application occasion, a very large high-frequency common mode voltage and leakage current are generated in the switching action process of the device, and in order to reduce induced electromotive force generated during the switching of the high-frequency switch of the power device, reduce electromagnetic interference of a power supply device, improve the efficiency of power conversion of the power supply device, reduce high-frequency leakage current formed in the power conversion process of the power supply device, reduce safety risks of equipment and workers, and generally pertinently adopt a multi-level inverter to complete a power conversion task in a new energy power generation occasion.

However, if a three-level or multi-level inverter is used in a conventional two-stage or multi-stage power converter, it will make the system more complicated, increase the number of power devices and passive devices, increase the cost of the device design and the complexity of control, and reduce the reliability and stability of the system.

Disclosure of Invention

In view of the above, it is necessary to provide a single-stage boost inverter circuit, a control method and a power conversion apparatus, which can reduce the size, cost and complexity of the circuit and effectively reduce each harmonic component in the output power while performing boost inversion.

A first aspect of the present application provides a single-stage boost inverter circuit, comprising:

an input inverter bridge module;

an output inverter bridge module;

a first port of the capacitive energy storage unit is connected with a first port of the input inverter bridge module, a second port of the capacitive energy storage unit is connected with a second port of the input inverter bridge module, a third port of the capacitive energy storage unit is connected with a first port of the output inverter bridge module, a fourth port of the capacitive energy storage unit is connected with a second port of the output inverter bridge module, the first port of the capacitive energy storage unit is used for being connected with a positive output end of a direct-current power supply, and the fourth port of the capacitive energy storage unit is used for being connected with a negative output end of the direct-current power supply and the ground;

the first port of the inductive energy storage backflow prevention unit is connected with the third port of the input inverter bridge module, the second port of the inductive energy storage backflow prevention unit is connected with the fourth port of the input inverter bridge module, the third port of the inductive energy storage backflow prevention unit is connected with the third port of the output inverter bridge module, and the fourth port of the inductive energy storage backflow prevention unit is connected with the fourth port of the output inverter bridge module;

the inductive energy storage anti-reflux unit outputs preset boosting alternating current to a next-stage load by respectively controlling the input inverter bridge module and the output inverter bridge module to act cooperatively.

In the single-stage boost inverter circuit in the above embodiment, the inductive energy storage anti-reflux unit is connected in series between the input inverter bridge module and the output inverter bridge module, and the capacitive energy storage unit is arranged to cooperate with the input inverter bridge module, the output inverter bridge module and the inductive energy storage anti-reflux unit to realize that the input direct current is inverted and boosted to the preset boost alternating current and then output to the next-stage load. Due to the cooperative action of the input inverter bridge module and the output inverter bridge module, the harmonic content in the voltage output to the next-stage load is effectively reduced, and the waveform quality can be improved while the volumes of the input filter element and the output filter element are reduced. Because the single-stage boost inverter circuit that provides in this application can be realized the electric energy transformation of new forms of energy electricity generation occasion by two-stage power conversion originally in one-level conversion, can reduce power conversion device's design cost effectively, improve power conversion device's price/performance ratio and integrated level.

In one embodiment, the inductive energy storage backflow prevention unit includes:

a first input port of the first anti-backflow module is connected with a third port of the input inverter bridge module, and a second input port of the first anti-backflow module is connected with a fourth port of the input inverter bridge module;

the first port of the inductive energy storage unit is connected with the output port of the first anti-reflux module;

an input port of the second anti-reflux module is connected with a second port of the inductive energy storage unit, a first output port of the second anti-reflux module is connected with a third port of the output inverter bridge module, and a second output port of the second anti-reflux module is connected with a fourth port of the output inverter bridge module.

In the single-stage boost inverter circuit in the above embodiment, the inductive energy storage backflow prevention unit includes a first backflow prevention module, an inductive energy storage unit, and a second backflow prevention module, wherein the inductive energy storage unit is connected in series between the first backflow prevention module and the second backflow prevention module, so that the first backflow prevention module, the inductive energy storage unit, and the second backflow prevention module cooperate with the input inverter bridge module and the output inverter bridge module to act, so as to implement inverting and boosting the input dc power to a preset boost ac power and then outputting the boost ac power to a subsequent stage of load.

In one embodiment, the first backflow prevention module includes:

the anode of the first diode is connected with the third port of the input inverter bridge module, and the cathode of the first diode is connected with the first port of the inductive energy storage unit;

and the anode of the second diode is connected with the fourth port of the input inverter bridge module, and the cathode of the second diode is connected with the first port of the inductive energy storage unit.

In one embodiment, the second backflow prevention module includes:

the anode of the third diode is connected with the second port of the inductive energy storage unit, and the cathode of the third diode is connected with the third port of the output inverter bridge module;

and the anode of the fourth diode is connected with the second port of the inductive energy storage unit, and the cathode of the fourth diode is connected with the fourth port of the output inverter bridge module.

In one embodiment, the capacitive energy storage unit includes:

the first port of the input energy storage unit is connected with the first port of the input inverter bridge module, and the second port of the input energy storage unit is connected with the second port of the output inverter bridge module;

and a first port of the output energy storage unit is connected with a first port of the output inverter bridge module, a second port of the output energy storage unit is connected with a second port of the input inverter bridge module, and a third port of the output energy storage unit is connected with a third port of the input energy storage unit.

In one embodiment, the input energy storage unit comprises a first capacitor and a second capacitor connected in series, wherein an input port of the first capacitor is connected with a first port of the input inverter bridge module, an output port of the second capacitor is connected with a second port of the output inverter bridge module, and an output port of the first capacitor is connected with a third port of the output energy storage unit; and/or

The output energy storage unit comprises a third capacitor and a fourth capacitor which are connected in series, wherein an input port of the third capacitor is connected with a first port of the output inverter bridge module, an output port of the third capacitor is connected with an output port of the first capacitor and an input port of the second capacitor, and an output port of the fourth capacitor is connected with a second port of the input inverter bridge module.

In one embodiment, the input inverter bridge module includes:

the first port of the first upper bridge arm switch unit is connected with the first port of the capacitive energy storage unit;

a first lower bridge arm switch unit, a first port of which is connected with a second port of the first upper bridge arm switch unit;

the first port of the second upper bridge arm switch unit is connected with the first port of the capacitive energy storage unit;

a second lower bridge arm switch unit, a first port of which is connected with a second port of the second upper bridge arm switch unit;

the second port of the first upper bridge arm switch unit is connected with the first port of the inductive energy storage backflow prevention unit, and the second port of the second upper bridge arm switch unit is connected with the second port of the inductive energy storage backflow prevention unit.

In one embodiment, the first upper bridge arm switch unit comprises a first high-frequency switch tube, and a drain electrode of the first high-frequency switch tube is connected with a first port of the capacitive energy storage unit;

the first lower bridge arm switch unit comprises a second high-frequency switch tube, the drain electrode of the second high-frequency switch tube is connected with the source electrode of the first high-frequency switch tube, and the source electrode of the second high-frequency switch tube is connected with the second port of the capacitive energy storage unit;

the second upper bridge arm switch unit comprises a third high-frequency switch tube, and the drain electrode of the third high-frequency switch tube is connected with the first port of the capacitive energy storage unit;

the second lower bridge arm switch unit comprises a fourth high-frequency switch tube, the drain electrode of the fourth high-frequency switch tube is connected with the source electrode of the third high-frequency switch tube, and the source electrode of the fourth high-frequency switch tube is connected with the second port of the capacitive energy storage unit;

the source electrode of the first high-frequency switching tube is connected with the first port of the inductive energy storage backflow prevention unit, and the source electrode of the third high-frequency switching tube is connected with the second port of the inductive energy storage backflow prevention unit.

In one embodiment, the output inverter bridge module includes:

a first port of the third upper bridge arm switch unit is connected with a third port of the capacitive energy storage unit;

a first port of the third lower bridge arm switch unit is connected with a second port of the third upper bridge arm switch unit, and a second port of the third lower bridge arm switch unit is connected with a fourth port of the capacitive energy storage unit;

a first port of the fourth upper bridge arm switch unit is connected with a third port of the capacitive energy storage unit;

a first port of the fourth lower bridge arm switch unit is connected with a second port of the fourth upper bridge arm switch unit, and a second port of the fourth lower bridge arm switch unit is connected with a fourth port of the capacitive energy storage unit;

the second port of the third upper bridge arm switch unit is connected with the third port of the inductive energy storage backflow prevention unit, and the second port of the fourth upper bridge arm switch unit is connected with the fourth port of the inductive energy storage backflow prevention unit.

In one embodiment, the third upper bridge arm switching unit comprises a fifth high-frequency switching tube, and the drain electrode of the fifth high-frequency switching tube is connected with the third port of the capacitive energy storage unit;

the third lower bridge arm switch unit comprises a sixth high-frequency switch tube, the drain electrode of the sixth high-frequency switch tube is connected with the source electrode of the fifth high-frequency switch tube, and the source electrode of the sixth high-frequency switch tube is connected with the fourth port of the capacitive energy storage unit;

the fourth upper bridge arm switch unit comprises a seventh high-frequency switch tube, and the drain electrode of the seventh high-frequency switch tube is connected with the third port of the capacitive energy storage unit;

the fourth lower bridge arm switch unit comprises an eighth high-frequency switch tube, the drain electrode of the eighth high-frequency switch tube is connected with the source electrode of the seventh high-frequency switch tube, and the source electrode of the eighth high-frequency switch tube is connected with the fourth port of the capacitive energy storage unit.

In one embodiment, the method further comprises the following steps:

a first port of the first electromagnetic isolation module is connected with a third port of the input inverter bridge module, and a second port of the first electromagnetic isolation module is connected with a third port of the output inverter bridge module; and/or

And a first port of the second electromagnetic isolation module is connected with the fourth port of the input inverter bridge module, and a second port of the second electromagnetic isolation module is connected with the fourth port of the output inverter bridge module.

In one embodiment, the first electromagnetic isolation module comprises a first high frequency transformer, a first port of the first high frequency transformer is connected with a third port of the input inverter bridge module, and a second port of the first high frequency transformer is connected with a third port of the output inverter bridge module; and/or

The second electromagnetic isolation module comprises a second high-frequency transformer, a first port of the second high-frequency transformer is connected with a fourth port of the input inverter bridge module, and a second port of the second high-frequency transformer is connected with a fourth port of the output inverter bridge module.

In one embodiment, the single-stage boost inverter circuit further includes a filter unit, a first port of the filter unit is connected to the output port of the first high-frequency transformer, and a second port of the filter unit is connected to the output port of the second high-frequency transformer.

A second aspect of the present application provides a power conversion apparatus, including a single-stage boost inverter circuit as described in any of the embodiments of the present application, configured to convert an input dc power into a preset boost ac power.

A third aspect of the present application provides a single-stage boosting inversion control method, including:

generating an input inverter bridge control signal and an output inverter bridge control signal according to the first carrier input signal, the second carrier input signal and the first modulation wave input signal;

controlling the on-off of each switch unit in the input inverter bridge module based on the input inverter bridge control signal, and controlling the on-off of each switch unit in the output inverter bridge module based on the output inverter bridge control signal, so that the inductive energy storage anti-reflux unit outputs preset boosting alternating current to a next-stage load; the first port of the inductive energy storage backflow prevention unit is connected with the third port of the input inverter bridge module, the second port of the inductive energy storage backflow prevention unit is connected with the fourth port of the input inverter bridge module, the third port of the inductive energy storage backflow prevention unit is connected with the third port of the output inverter bridge module, and the fourth port of the inductive energy storage backflow prevention unit is connected with the fourth port of the output inverter bridge module;

the first port of the input inverter bridge module is connected with the first port of the capacitive energy storage unit, the second port of the capacitive energy storage unit is connected with the second port of the input inverter bridge module, the third port of the capacitive energy storage unit is connected with the first port of the output inverter bridge module, the fourth port of the capacitive energy storage unit is connected with the second port of the output inverter bridge module, the first port of the input inverter bridge module is used for being connected with the positive output end of the direct-current power supply, and the fourth port of the capacitive energy storage unit is used for being connected with the negative output end of the direct-current power supply and the ground.

In the single-stage boost inversion method in the above embodiment, an input inverter bridge control signal and an output inverter bridge control signal are generated according to a first carrier input signal, a second carrier input signal, and a first modulation wave input signal; and controlling the on-off of each switch unit in the input inverter bridge module based on the input inverter bridge control signal, and controlling the on-off of each switch unit in the output inverter bridge module based on the output inverter bridge control signal, so that the inductive energy storage anti-reflux unit outputs preset boosting alternating current to a next-stage load. The embodiment effectively reduces the harmonic content in the voltage output to the load of the next stage, and can improve the waveform quality while reducing the volumes of the input filter element and the output filter element.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain drawings of other embodiments based on these drawings without any creative effort.

Fig. 1 is a schematic circuit diagram of a single-stage boost inverter circuit provided in a first embodiment of the present application.

Fig. 2 is a schematic circuit diagram of a single-stage boost inverter circuit according to a second embodiment of the present application.

Fig. 3 is a schematic circuit diagram of a single-stage boost inverter circuit according to a third embodiment of the present application.

Fig. 4 is a schematic circuit diagram of a single-stage boost inverter circuit provided in a fourth embodiment of the present application.

Fig. 5 is a schematic circuit diagram of a single-stage boost inverter circuit provided in a fifth embodiment of the present application.

Fig. 6 is a schematic circuit diagram of a single-stage boost inverter circuit provided in a sixth embodiment of the present application.

Fig. 7 is a circuit diagram of a single-stage boost inverter circuit according to an embodiment of the present disclosure.

Fig. 8 is a circuit diagram of a single-stage boost inverter circuit according to another embodiment of the present application.

Fig. 9 is a circuit schematic diagram of a single-stage boost inverter circuit according to another embodiment of the present application.

Fig. 10a is a waveform diagram illustrating a modulation key of a single-stage boost inverter circuit according to an embodiment of the present application.

Fig. 10b is a modulation key waveform diagram of a single-stage boost inverter circuit according to another embodiment of the present application.

Fig. 11a is an equivalent circuit diagram of a single-stage boost inverter circuit in a first positive operating mode according to an embodiment of the present disclosure.

Fig. 11b is an equivalent circuit diagram of a single-stage boost inverter circuit in a second positive operating mode according to an embodiment of the present application.

Fig. 11c is an equivalent circuit diagram of a single-stage boost inverter circuit in a third positive operating mode according to an embodiment of the present application.

Fig. 11d is an equivalent circuit diagram of a single-stage boost inverter circuit in a fourth positive operating mode according to an embodiment of the present disclosure.

Fig. 11e is an equivalent circuit diagram of a single-stage boost inverter circuit in a fifth positive operating mode according to an embodiment of the present disclosure.

Fig. 11f is an equivalent circuit diagram of a single-stage boost inverter circuit in a sixth positive operating mode according to an embodiment of the present application.

Fig. 11g is an equivalent circuit diagram of a single-stage boost inverter circuit in a seventh positive operating mode according to an embodiment of the present disclosure.

Fig. 12a is an equivalent circuit diagram of a single-stage boost inverter circuit in a first negative operating mode according to an embodiment of the present disclosure.

Fig. 12b is an equivalent circuit diagram of a single-stage boost inverter circuit in the second negative operating mode according to an embodiment of the present disclosure.

Fig. 12c is an equivalent circuit diagram of a single-stage boost inverter circuit in a third negative operating mode according to an embodiment of the present application.

Fig. 12d is an equivalent circuit diagram of a single-stage boost inverter circuit in a fourth negative operating mode according to an embodiment of the present disclosure.

Fig. 12e is an equivalent circuit diagram of a single-stage boost inverter circuit in a fifth negative operating mode according to an embodiment of the present application.

Fig. 12f is an equivalent circuit diagram of a single-stage boost inverter circuit in a sixth negative operating mode according to an embodiment of the present application.

Fig. 12g is an equivalent circuit diagram of a single-stage boost inverter circuit in a seventh negative operating mode according to an embodiment of the present disclosure.

Fig. 13 is a schematic structural diagram of a single-stage boosting inversion packaging module according to an embodiment of the present application.

Fig. 14a is a schematic structural diagram of a III-N transistor provided in an embodiment of the present application.

Fig. 14b is a schematic structural diagram of a III-N transistor provided in another embodiment of the present application.

Fig. 14c is a schematic structural diagram of a III-N transistor provided in another embodiment of the present application.

Fig. 15 is a schematic view of a semiconductor structure of a III-N diode according to an embodiment of the present application.

Fig. 16a is a schematic structural diagram of a III-N diode provided in an embodiment of the present application.

Fig. 16b is a schematic structural diagram of a III-N diode provided in another embodiment of the present application.

Fig. 17a is a schematic view of a package structure of a III-N diode according to an embodiment of the present application.

Fig. 17b is a schematic view of a package structure of a III-N diode according to another embodiment of the present application.

Fig. 18a is a waveform curve diagram of the current of the first boost inductor and the first carrier input signal of a single-stage boost inverter circuit according to an embodiment of the present application.

Fig. 18b is a waveform curve diagram of a voltage difference between a drain and a source of each switching tube, a terminal voltage of a third capacitor and a terminal voltage of a fourth capacitor of a single-stage boost inverter circuit according to an embodiment of the present application.

Fig. 18c is a schematic diagram illustrating waveforms of an output voltage of an input dc power source, a terminal voltage of a load, and an output side potential difference VNL of a single-stage boost inverter circuit according to an embodiment of the present disclosure.

Detailed Description

To facilitate an understanding of the present application, the present application will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present application are illustrated in the accompanying drawings. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Where the terms "comprising," "having," and "including" are used herein, another element may be added unless an explicit limitation is used, such as "only," "consisting of … …," etc. Unless mentioned to the contrary, terms in the singular may include the plural and are not to be construed as being one in number.

It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present application.

In this application, unless otherwise expressly stated or limited, the terms "connected" and "connecting" are used broadly and encompass, for example, direct connection, indirect connection via an intermediary, communication between two elements, or interaction between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

Referring to fig. 1, in an embodiment of the present application, a single-stage boost inverter circuit 100 is provided, including an input inverter bridge module 10, an output inverter bridge module 20, a capacitive energy storage unit 30, and an inductive energy storage backflow prevention unit 40, where a first port of the capacitive energy storage unit 30 is connected to a first port of the input inverter bridge module 10, a second port of the capacitive energy storage unit 30 is connected to a second port of the input inverter bridge module 10, a third port of the capacitive energy storage unit 30 is connected to a first port of the output inverter bridge module 20, a fourth port of the capacitive energy storage unit 30 is connected to a second port of the output inverter bridge module 20, the first port of the capacitive energy storage unit 30 is used for being connected to a positive output terminal of a dc power supply 100, and the fourth port of the capacitive energy storage unit 30 is used for being connected to a negative output terminal of the dc power supply 100 and a ground; the first port of the inductive energy storage backflow prevention unit 40 is connected with the third port of the input inverter bridge module 10, the second port of the inductive energy storage backflow prevention unit 40 is connected with the fourth port of the input inverter bridge module 10, the third port of the inductive energy storage backflow prevention unit 40 is connected with the third port of the output inverter bridge module 20, and the fourth port of the inductive energy storage backflow prevention unit 40 is connected with the fourth port of the output inverter bridge module 20; the inductive energy storage backflow prevention unit 40 outputs preset boost alternating current to a next-stage load by respectively controlling the input inverter bridge module 10 and the output inverter bridge module 20 to act cooperatively.

Specifically, please refer to fig. 1, an inductive energy storage backflow prevention unit 40 is connected in series between the input inverter bridge module 10 and the output inverter bridge module 20, and the capacitive energy storage unit 30 is arranged to cooperate with the input inverter bridge module 10, the output inverter bridge module 20 and the inductive energy storage backflow prevention unit 40 to realize that the input dc power is inverted and boosted to a preset boost ac power and then output to a next-stage load. Due to the cooperative action of the input inverter bridge module 10 and the output inverter bridge module 20, the harmonic content in the voltage output to the next-stage load is effectively reduced, and the waveform quality can be improved while the volumes of the input filter element and the output filter element are reduced. Because the single-stage boost inverter circuit that provides in this application can be realized the electric energy transformation of new forms of energy electricity generation occasion by two-stage power conversion originally in one-level conversion, can reduce power conversion device's design cost effectively, improve power conversion device's price/performance ratio and integrated level.

Further, referring to fig. 2, in an embodiment of the present application, the inductive energy storage backflow prevention unit 40 includes a first backflow prevention module 41, an inductive energy storage unit 42, and a second backflow prevention module 43, a first input port of the first backflow prevention module 41 is connected to a third port of the input inverter bridge module 10, and a second input port of the first backflow prevention module 41 is connected to a fourth port of the input inverter bridge module 10; a first port of the inductive energy storage unit 42 is connected to an output port of the first backflow prevention module 41; an input port of the second backflow prevention module 43 is connected to the second port of the inductive energy storage unit 42, a first output port of the second backflow prevention module 43 is connected to the third port of the output inverter bridge module 20, and a second output port of the second backflow prevention module 43 is connected to the fourth port of the output inverter bridge module 20.

Specifically, please refer to fig. 2, the inductive energy storage backflow prevention unit 40 includes a first backflow prevention module 41, an inductive energy storage unit 42, and a second backflow prevention module 43, wherein the inductive energy storage unit 42 is connected in series between the first backflow prevention module 41 and the second backflow prevention module 43, so that the first backflow prevention module 41, the inductive energy storage unit 42, and the second backflow prevention module 43 cooperate with the input inverter bridge module 10 and the output inverter bridge module 20 to operate, so as to implement inverting and boosting the input dc power to a preset boosted ac power and then outputting the boosted ac power to a subsequent load. In one embodiment of the present application, the inductive energy storage unit 42 may be a first boost inductor L1.

Further, referring to fig. 3, in an embodiment of the present application, the first anti-backflow module 41 includes a first diode D1 and a second diode D2, an anode of the first diode D1 is connected to the third port of the input inverter bridge module 10, and a cathode of the first diode D1 is connected to the first port of the inductive energy storage unit 42; the anode of the second diode D2 is connected to the fourth port of the input inverter bridge module 10, and the cathode of the second diode D2 is connected to the first port of the inductive energy storage unit 42.

Further, with continued reference to fig. 3, in an embodiment of the present application, the second anti-backflow module 43 includes a third diode D3 and a fourth diode D4, an anode of the third diode D3 is connected to the second port of the inductive energy storage unit 42, and a cathode of the third diode D3 is connected to the third port of the output inverter bridge module 20; the anode of the fourth diode D4 is connected to the second port of the inductive energy storage unit 42, and the cathode of the fourth diode D4 is connected to the fourth port of the output inverter bridge module 20.

Further, referring to fig. 4, in an embodiment of the present application, the capacitive energy storage unit includes an input energy storage unit 31 and an output energy storage unit 32, a first port of the input energy storage unit 31 is connected to a first port of the input inverter bridge module 10, and a second port of the input energy storage unit 31 is connected to a second port of the output inverter bridge module 20; a first port of the output energy storage unit 32 is connected to a first port of the output inverter bridge module 20, a second port of the output energy storage unit 32 is connected to a second port of the input inverter bridge module 10, and a third port of the output energy storage unit 32 is connected to a third port of the input energy storage unit 31.

Further, referring to fig. 5, in an embodiment of the present application, the input energy storage unit 31 includes a first capacitor Cin1 and a second capacitor Cin2 connected in series, wherein an input port of the first capacitor Cin1 is connected to the first port of the input inverter bridge module, an output port of the second capacitor Cin2 is connected to the second port of the output inverter bridge module, and an output port of the first capacitor Cin1 is connected to the third port of the output energy storage unit 31.

Further, please refer to fig. 5 continuously, in an embodiment of the present application, the output energy storage unit includes a third capacitor Co1 and a fourth capacitor Co2 connected in series, wherein an input port of the third capacitor Co1 is connected to the first port of the output inverter bridge module, an output port of the third capacitor Co1 is connected to both an output port of the first capacitor Cin1 and an input port of the second capacitor Cin2, and an output port of the fourth capacitor Co2 is connected to the second port of the input inverter bridge module 10.

Further, referring to fig. 6, in an embodiment of the present application, the input inverter bridge module 10 includes a first upper bridge arm switch unit 11, a first lower bridge arm switch unit 12, a second upper bridge arm switch unit 13, and a second lower bridge arm switch unit 14, where a first port of the first upper bridge arm switch unit 11 is connected to a first port of the capacitive energy storage unit; a first port of the first lower bridge arm switch unit 12 is connected with a second port of the first upper bridge arm switch unit 11; a first port of the second upper bridge arm switch unit 13 is connected with a first port of the capacitive energy storage unit 30; a first port of the second lower arm switch unit 14 is connected with a second port of the second upper arm switch unit 13; the second port of the first upper bridge arm switch unit 11 is connected to the first port of the inductive energy storage backflow prevention unit 40, and the second port of the second upper bridge arm switch unit 13 is connected to the second port of the inductive energy storage backflow prevention unit 40.

Further, please refer to fig. 6 again, in an embodiment of the present application, the output inverter bridge module 20 includes a third upper bridge arm switch unit 21, a third lower bridge arm switch unit 22, a fourth upper bridge arm switch unit 23, and a fourth lower bridge arm switch unit 24, wherein a first port of the third upper bridge arm switch unit 21 is connected to a third port of the capacitive energy storage unit 30; a first port of the third lower bridge arm switch unit 22 is connected with a second port of the third upper bridge arm switch unit 21, and a second port of the third lower bridge arm switch unit 22 is connected with a fourth port of the capacitive energy storage unit 30; a first port of the fourth upper bridge arm switch unit 23 is connected with a third port of the capacitive energy storage unit 30; a first port of the fourth lower bridge arm switch unit 24 is connected with a second port of the fourth upper bridge arm switch unit 23, and a second port of the fourth lower bridge arm switch unit 24 is connected with a fourth port of the capacitive energy storage unit 30; the second port of the third upper arm switch unit 21 is connected to the third port of the inductive energy storage backflow prevention unit 40, and the second port of the fourth upper arm switch unit 23 is connected to the fourth port of the inductive energy storage backflow prevention unit 40.

Further, referring to fig. 7, in an embodiment of the present application, the first upper bridge arm switch unit 11 includes a first high frequency switch tube S1H, and a drain of the first high frequency switch tube S1H is connected to the first port of the capacitive energy storage unit 30; the first lower bridge arm switch unit 12 comprises a second high-frequency switch tube S1L, the drain of the second high-frequency switch tube S1L is connected with the source of the first high-frequency switch tube S1H, and the source of the second high-frequency switch tube S1L is connected with the second port of the capacitive energy storage unit 30; the second upper bridge arm switch unit 13 includes a third high-frequency switch tube S2H, and a drain of the third high-frequency switch tube S2H is connected to the first port of the capacitive energy storage unit 30; the second lower bridge arm switch unit 14 includes a fourth high-frequency switch tube S2L, a drain of the fourth high-frequency switch tube S2L is connected to a source of the third high-frequency switch tube S2H, and a source of the fourth high-frequency switch tube S2L is connected to the second port of the capacitive energy storage unit 30; the source of the first high frequency switch tube S1H is connected to the first port of the inductive energy storage backflow prevention unit 40, and the source of the third high frequency switch tube S2H is connected to the second port of the inductive energy storage backflow prevention unit 40.

Further, with continuing reference to fig. 7, in an embodiment of the present application, the third upper arm switch unit 21 includes a fifth high-frequency switch tube S3H, and a drain of the fifth high-frequency switch tube S3H is connected to the third port of the capacitive energy storage unit 30; the third lower bridge arm switch unit 22 comprises a sixth high-frequency switch tube S3L, a drain of the sixth high-frequency switch tube S3L is connected with a source of the fifth high-frequency switch tube S3H, and a source of the sixth high-frequency switch tube S3L is connected with the fourth port of the capacitive energy storage unit 30; the fourth upper arm switch unit 23 includes a seventh high frequency switch tube S4H, and a drain of the seventh high frequency switch tube S4H is connected to the third port of the capacitive energy storage unit 30; the fourth lower arm switch unit 24 includes an eighth high frequency switch tube S4L, a drain of the eighth high frequency switch tube S4L is connected to a source of the seventh high frequency switch tube S4H, and a source of the eighth high frequency switch tube S4L is connected to the fourth port of the capacitive energy storage unit 30.

Further, referring to fig. 8, in an embodiment of the present application, the single-stage boost inverter circuit further includes a first electromagnetic isolation module 51, a first port of the first electromagnetic isolation module 51 is connected to a third port of the input inverter bridge module 10, and a second port of the first electromagnetic isolation module 51 is connected to a third port of the output inverter bridge module 20.

Further, with continued reference to fig. 8, in an embodiment of the present application, the single-stage boost inverter circuit further includes a second electromagnetic isolation module 52, a first port of the second electromagnetic isolation module 52 is connected to the fourth port of the input inverter bridge module 10, and a second port of the second electromagnetic isolation module 52 is connected to the fourth port of the output inverter bridge module 20.

Further, referring to fig. 9, in an embodiment of the present application, the first electromagnetic isolation module includes a first high-frequency transformer T1, a first port of the first high-frequency transformer T1 is connected to the third port of the input inverter bridge module 10, and a second port of the first high-frequency transformer T1 is connected to the third port of the output inverter bridge module 20.

Further, referring to fig. 9, in an embodiment of the present application, the second electromagnetic isolation module includes a second high-frequency transformer T2, a first port of the second high-frequency transformer T2 is connected to the fourth port of the input inverter bridge module 10, and a second port of the second high-frequency transformer T2 is connected to the fourth port of the output inverter bridge module 20.

Further, with reference to fig. 9, in an embodiment of the present application, the inductive energy storage unit 42 may be a first boost inductor L1, a first port of the first boost inductor L1 is connected to a cathode of the first diode D1 and a cathode of the second diode D2, and a second port of the first boost inductor L1 is connected to an anode of the third diode D3 and an anode of the fourth diode D4.

Further, with continuing reference to fig. 9, in an embodiment of the present application, the input-side and output-side transmission ratios of the first high-frequency transformer T1 and the second high-frequency transformer T2 are all 1, and only the functions of electrical isolation and voltage clamping are realized. At this time, the input-output voltage transfer ratio of the single-stage boost inverter circuit is (M/(1-D)), where D is the duty ratio of the first fixed pulse width signal Vpwm1 (or the second fixed pulse width signal Vpwm2), and M is the duty ratio of the first sinusoidal pulse width signal Vspwm1 (or the second sinusoidal pulse width signal Vspwm 2). In other embodiments of the present application, the transmission ratio between the input side and the output side of the electromagnetic isolation module is N (N ≧ 2), and the input-output voltage transmission ratio of the single-stage boost inverter circuit can be raised to (N × M/(1-D)).

Further, with reference to fig. 9, in an embodiment of the present application, the single-stage boost inverter circuit further includes a filtering unit 60, a first port of the filtering unit 60 is connected to a third port of the first high-frequency transformer T1, a second port of the filtering unit 60 is connected to a third port of the second high-frequency transformer T2, and the filtering unit 60 is configured to filter the output voltage of the inductive energy-storage backflow prevention unit.

Further, in an embodiment of the present application, the filtering unit in the single-stage boost inverter circuit may be one of an L-type filtering unit, an L-C-type filtering unit, or an L-C-L-type filtering unit.

Further, referring to fig. 9, 10a and 10b, in an embodiment of the present application, an input inverter bridge control signal and an output inverter bridge control signal may be sequentially generated via a first comparison module Comp1 (not shown), a second comparison module Comp2 (not shown), a third comparison module Comp3 (not shown) and a fourth comparison module Comp3 (not shown) based on a first carrier input signal Vtri1, a second carrier input signal Vtri2 and a first modulated wave input signal Vsine, where the input inverter bridge control signal includes a first switching tube driving signal VgsH1 for controlling on/off of a first high frequency switching tube S1H, a second switching tube driving signal vgvsl 1 for controlling on/off of a second high frequency switching tube S1L, a third switching tube driving signal vgh 2 for controlling on/off of a third high frequency switching tube S2H, and a fourth switching tube driving signal 2 gsl 2L for controlling on/off of a fourth high frequency switching tube S2L, A fifth switching tube driving signal VgsH3 for controlling the on-off of the fifth high-frequency switching tube S3H, a sixth switching tube driving signal VgsL3 for controlling the on-off of the sixth high-frequency switching tube S3L, a seventh switching tube driving signal VgsH4 for controlling the on-off of the seventh high-frequency switching tube S4H, and an eighth switching tube driving signal VgsL4 for controlling the on-off of the eighth high-frequency switching tube S4L. The first modulated wave input signal Vsine and the first carrier input signal Vtri1 pass through a first comparison module Comp1 to generate a first switching tube driving signal VgsH1 and a second switching tube driving signal VgsL 1; the inverted signal of the first modulated wave input signal Vsine and the first carrier input signal Vtri1 pass through the second comparing module Comp2 to generate a third switching tube driving signal VgsH2 and a fourth switching tube driving signal VgsL 2; the first modulated wave input signal Vsine and the second carrier input signal Vtri2 pass through a third comparison module Comp3 to generate a fifth switching tube driving signal VgsH3 and a sixth switching tube driving signal VgsL 3; the inverted signal of the first modulated wave input signal Vsine and the second carrier input signal Vtri2 pass through the fourth comparing module Comp4 to generate the seventh switching tube driving signal VgsH4 and the eighth switching tube driving signal VgsL 4.

Further, with continued reference to fig. 10a and 10b, in an embodiment of the present application, the phase difference between the first carrier input signal Vtri1 and the second carrier input signal Vtri2 is 180 °, the first carrier input signal Vtri1 and the second carrier input signal Vtri2 may both be sawtooth signals, and the first modulated wave input signal Vsine may be a sine wave signal.

Based on the modulation key waveform diagram (sine positive half cycle), the single-stage boost inverter circuit mainly comprises seven working states in different stages within a complete carrier cycle (Tvtri1 or Tvtri1), as shown in fig. 11 a-11 g. The operation principle and characteristics of the single-stage boost inverter circuit will be briefly described with reference to fig. 9 and fig. 11a to 11 g. To simplify the analysis process, the following basic assumptions can be made: 1. all power and filter elements are ideal devices. 2. The capacitive reactance values of the first capacitor Cin1, the second capacitor Cin2, the third capacitor Co1 and the fourth capacitor Co2 are all large enough, and voltage ripples can be ignored, so that the voltage value Vcin1 at two ends of the first capacitor Cin1 is basically equal to the voltage value Vcin2 at two ends of the second capacitor Cin2 and is equal to half of the voltage value Vcin input to two ends of the energy storage unit; the voltage value Vco1 across the third capacitor Co1 is substantially equal to the voltage value Vco2 across the fourth capacitor Co2, and is equal to half of the voltage value Vco across the output energy storage unit. 3. The potential at the point of the first power ground GND1 is 0. 4. The voltage transfer ratios of the first high frequency transformer T1 and the second high frequency transformer T2 are both 1.

Specifically, in the equivalent circuit diagram of the circuit shown in fig. 9 when the circuit operates in the first positive operating mode, as shown in fig. 11a, the first high-frequency switch tube S1H, the third high-frequency switch tube S2H, the sixth high-frequency switch tube S3L and the seventh high-frequency switch tube S4H are all turned on. On the one hand, the output current of the dc power source Uin charges the first boost inductor L1 through the first high-frequency switch tube S1H and the sixth high-frequency switch tube S3L, and charges the first boost inductor L1 through the third high-frequency switch tube S2H and the sixth high-frequency switch tube S3L through the second path, so that the first boost inductor L1 stores energy, and the current flowing through the first boost inductor L1 gradually increases; on the other hand, the third capacitor Co1 and the first capacitor Cin1 supply energy to the filtering unit through the third high-frequency switch tube S2H, the seventh high-frequency switch tube S4H and the second high-frequency transformer T2. The potential difference VNL between the input side positive voltage node N and the negative voltage node L of the filter unit is equal to (Vin + Vco1-Vcin1) ═ 1/2(Vco + Vcin), the voltage difference between the drain and the source of the second high-frequency switch tube S1L is equal to Vcin1+ Vco2, the voltage difference between the drain and the source of the fourth high-frequency switch tube S2L is equal to Vcin1+ Vco2, the voltage difference between the drain and the source of the fifth high-frequency switch tube S3H is equal to Vcin2+ Vco1, and the voltage difference between the drain and the source of the eighth high-frequency switch tube S4L is equal to Vcin2+ Vco 1.

Specifically, in the equivalent circuit diagram of the circuit shown in fig. 9 when operating in the second positive operating mode, as shown in fig. 11b, the first high-frequency switch tube S1H, the fourth high-frequency switch tube S2L, the sixth high-frequency switch tube S3L and the seventh high-frequency switch tube S4H are all turned on. On the one hand, the current output by the direct current power supply Uin charges the first boost inductor L1 through the first high-frequency switch tube S1H and the sixth high-frequency switch tube S3L, the first boost inductor L1 stores energy, and the current flowing through the first boost inductor L1 gradually rises; on the other hand, the third capacitor Co1 and the fourth capacitor Co2 supply energy to the filtering unit through the fourth high-frequency switch tube S2L, the seventh high-frequency switch tube S4H and the second high-frequency transformer T2. The potential difference VNL between the positive voltage node N and the negative voltage node L on the input side of the filter unit is equal to (Vin + Vco1+ Vco2) — (Vco + Vcin), the voltage difference between the drain and the source of the second high-frequency switch tube S1L is equal to Vcin1+ Vco2, the voltage difference between the drain and the source of the third high-frequency switch tube S2H is equal to Vcin1+ Vco2, the voltage difference between the drain and the source of the fifth high-frequency switch tube S3H is equal to Vcin2+ Vco1, and the voltage difference between the drain and the source of the eighth high-frequency switch tube S4L is equal to Vcin2+ Vco 1.

Specifically, the equivalent circuit diagram of the circuit shown in fig. 9 when operating in the third positive operating mode is shown in fig. 11c, and the first high-frequency switch tube S1H, the fourth high-frequency switch tube S2L, the fifth high-frequency switch tube S3H and the seventh high-frequency switch tube S4H are all turned on. On the one hand, the first boost inductor L1 experiences a reverse voltage drop of (Vco1-Vcin1) and starts to discharge energy, and the current flowing through the first boost inductor gradually decreases; on the other hand, the third capacitor Co1 and the fourth capacitor Co2 supply energy to the filter unit through the fourth high-frequency switch tube S2L, the seventh high-frequency switch tube S4H and the second high-frequency transformer T2. The potential difference VNL between the input side positive voltage node N and the negative voltage node L of the filter unit is equal to (Vco2+ Vcin1) ═ 1/2(Vco + Vcin), the voltage of the second high-frequency switch tube S1L is equal to Vcin1+ Vco2, the voltage difference between the drain and the source of the third high-frequency switch tube S2H is equal to Vcin1+ Vco2, the voltage difference between the drain and the source of the sixth high-frequency switch tube S3L is equal to Vcin2+ Vco1, and the voltage difference between the drain and the source of the seventh high-frequency switch tube S4L is equal to Vcin2+ Vco 1.

Specifically, the equivalent circuit diagram of the circuit shown in fig. 9 when operating in the fourth positive operating mode is shown in fig. 11d, and the first high-frequency switch tube S1H, the fourth high-frequency switch tube S2L, the sixth high-frequency switch tube S3L and the eighth high-frequency switch tube S4L are all turned on. On the one hand, the current output by the dc power supply charges the first boost inductor L1 through the first high-frequency switch S1H and the sixth high-frequency switch S3L, and charges the first boost inductor L1 through the second path through the first high-frequency switch S1H and the eighth high-frequency switch S4L, the first boost inductor L1 stores energy, and the current flowing through the first boost inductor L1 gradually increases; on the other hand, the third capacitor Co2 and the second capacitor Cin2 supply energy to the filtering unit through the fourth high-frequency switch tube S2L, the eighth high-frequency switch tube S4L and the second high-frequency transformer T2. The potential difference VNL between the input side positive voltage node N and the negative voltage node L of the filter unit is equal to (Vin + Vco2-Vcin2) ═ 1/2(Vco + Vcin), the voltage difference between the drain and the source of the second high-frequency switch tube S1L is equal to Vcin1+ Vco2, the voltage difference between the drain and the source of the third high-frequency switch tube S2H is equal to Vcin1+ Vco2, the voltage difference between the drain and the source of the fifth high-frequency switch tube S3H is equal to Vcin2+ Vco1, and the voltage difference between the drain and the source of the sixth high-frequency switch tube S4H is equal to Vcin2+ Vco 1.

Specifically, in the equivalent circuit diagram of the circuit shown in fig. 9 when the circuit operates in the fifth positive operating mode, as shown in fig. 11e, the second high-frequency switch tube S1L, the fourth high-frequency switch tube S2L, the sixth high-frequency switch tube S3L and the seventh high-frequency switch tube S4H are all turned on. On the one hand, the first boost inductor L1 experiences a reverse voltage drop of (Vco2-Vcin2) and starts to discharge energy, and the current flowing through the first boost inductor gradually decreases; on the other hand, the third capacitor Co1 and the fourth capacitor Co2 supply energy to the filtering unit through the fourth high-frequency switch tube S2L, the seventh high-frequency switch tube S4H and the second high-frequency transformer T2. The potential difference VNL between the input side positive voltage node N and the negative voltage node L of the filter unit is equal to (Vco1+ Vcin2) ═ 1/2(Vco + Vcin), the voltage difference between the drain and the source of the first high-frequency switch tube S1H is equal to Vcin1+ Vco2, the voltage difference between the drain and the source of the third high-frequency switch tube S2H is equal to Vcin1+ Vco2, the voltage difference between the drain and the source of the fifth high-frequency switch tube S3H is equal to Vcin2+ Vco1, and the voltage difference between the drain and the source of the eighth high-frequency switch tube S4L is equal to Vcin2+ Vco 1.

Specifically, in the equivalent circuit diagram of the circuit shown in fig. 9 when the circuit operates in the sixth positive operating mode, as shown in fig. 11f, the first high-frequency switch tube S1H, the third high-frequency switch tube S2H, the fifth high-frequency switch tube S3H and the seventh high-frequency switch tube S4H are all turned on. On the one hand, the first boost inductor L1 experiences a reverse voltage drop of (Vco1-Vcin1) and starts to discharge energy, and the current flowing through the first boost inductor gradually decreases; on the other hand, the third capacitor Co1 and the first capacitor Cin1 supply energy to the filtering unit through the third high-frequency switch tube S2H, the seventh high-frequency switch tube S4H and the second high-frequency transformer T2. The potential difference VNL between the input side positive voltage node N and the negative voltage node L of the filter unit is equal to 0, the voltage difference between the drain and the source of the second high-frequency switch tube S1L is equal to Vcin1+ Vco2, the voltage difference between the drain and the source of the fourth high-frequency switch tube S2L is equal to Vcin1+ Vco2, the voltage difference between the drain and the source of the sixth high-frequency switch tube S3L is equal to Vcin2+ Vco1, and the voltage difference between the drain and the source of the eighth high-frequency switch tube S4L is equal to Vcin2+ Vco 1.

Specifically, in the equivalent circuit diagram of the circuit shown in fig. 9 when the circuit operates in the seventh positive operating mode, as shown in fig. 11g, the second high-frequency switch tube S1L, the fourth high-frequency switch tube S2L, the sixth high-frequency switch tube S3L and the eighth high-frequency switch tube S4L are all turned on. On the one hand, the first boost inductor L1 experiences a reverse voltage drop of (Vco2-Vcin2) and starts to discharge energy, and the current flowing through the first boost inductor gradually decreases; on the other hand, the fourth capacitor Co2 and the second capacitor Cin2 supply energy to the filtering unit through the fourth high-frequency switch tube S2L, the eighth high-frequency switch tube S4L and the second high-frequency transformer T2. The potential difference VNL between the input side positive voltage node N and the negative voltage node L of the filter unit is equal to 0, the voltage difference between the drain and the source of the first high-frequency switch tube S1H is equal to Vcin1+ Vco2, the voltage difference between the drain and the source of the third high-frequency switch tube S2H is equal to Vcin1+ Vco2, the voltage difference between the drain and the source of the fifth high-frequency switch tube S3H is equal to Vcin2+ Vco1, and the voltage difference between the drain and the source of the seventh high-frequency switch tube S4H is equal to Vcin2+ Vco 1.

In summary, the single-stage boost inverter circuit mainly operates in the seven operating modes when the modulation wave is in the sine positive half cycle, so as to uninterruptedly convert the input dc power into the preset boost ac power and output the preset boost ac power to the subsequent stage of load. In a sine positive half cycle, the potential difference VNL between the positive voltage node N and the negative voltage node L on the input side of the filter unit has 1/2(Vco + Vcin), (Vco + Vcin) and 0.

Further, based on the above modulation key waveform diagram (sine minus half cycle), the single-stage boost inverter circuit mainly comprises seven different stages of operating states within one complete carrier cycle (Tvtri1 or Tvtri1), as shown in fig. 12a to 12 g. The operation principle and characteristics of the single-stage boost inverter circuit will be briefly described with reference to fig. 9 and fig. 12a to 12 g.

Specifically, in the equivalent circuit diagram of the circuit shown in fig. 9 when the circuit operates in the first negative operation mode, as shown in fig. 12a, the first high-frequency switch tube S1H, the third high-frequency switch tube S2H, the fifth high-frequency switch tube S3H and the eighth high-frequency switch tube S4L are all turned on. On the one hand, the output current of the direct current power supply Uin charges the first boost inductor L1 through the third high-frequency switch tube S2H and the eighth high-frequency switch tube S4L, and charges the first boost inductor L1 through the second path through the first high-frequency switch tube S1H and the eighth high-frequency switch tube S4L, the first boost inductor L1 stores energy, and the current flowing through the first boost inductor L1 gradually rises; on the other hand, the third capacitor Co1 and the first capacitor Cin1 supply energy to the filter unit through the fifth high-frequency switch tube S3H, the first high-frequency switch tube S1H and the first high-frequency transformer T1. The potential difference VNL between the input side positive voltage node N and the negative voltage node L of the filter unit is equal to (Vcin1-Vin-Vco1) — 1/2(Vco + Vcin), the voltage difference between the drain and the source of the second high-frequency switch tube S1L is equal to Vcin1+ Vco2, the voltage difference between the drain and the source of the fourth high-frequency switch tube S2L is equal to Vcin1+ Vco2, the voltage difference between the drain and the source of the sixth high-frequency switch tube S3L is equal to Vcin2+ Vco1, and the voltage difference between the drain and the source of the seventh high-frequency switch tube S4H is equal to Vcin2+ Vco 1.

Specifically, in the equivalent circuit diagram of the circuit shown in fig. 9 when the circuit operates in the second negative operation mode, as shown in fig. 12b, the second high-frequency switch tube S1L, the third high-frequency switch tube S2H, the fifth high-frequency switch tube S3H and the eighth high-frequency switch tube S4L are all turned on. On the one hand, the output current of the direct current power supply Uin charges the first boost inductor L1 through the third high-frequency switch tube S2H and the eighth high-frequency switch tube S4L, the first boost inductor L1 stores energy, and the current flowing through the first boost inductor L1 gradually rises; on the other hand, the third capacitor Co1 and the fourth capacitor Co2 supply energy to the filter unit through the second high-frequency switch tube S1L, the fifth high-frequency switch tube S3H and the first high-frequency transformer T1. The potential difference VNL between the input side positive voltage node N and the negative voltage node L of the filter unit is equal to- (Vin + Vco1+ Vco2) — (Vco + Vcin), the voltage difference between the drain and the source of the first high-frequency switch tube S1H is equal to Vcin1+ Vco2, the voltage difference between the drain and the source of the fourth high-frequency switch tube S2L is equal to Vcin1+ Vco2, the voltage difference between the drain and the source of the sixth high-frequency switch tube S3L is equal to Vcin2+ Vco1, and the voltage difference between the drain and the source of the seventh high-frequency switch tube S4H is equal to Vcin2+ Vco 1.

Specifically, in the equivalent circuit diagram of the circuit shown in fig. 9 when the circuit operates in the third negative operating mode, as shown in fig. 12c, the second high-frequency switch tube S1L, the third high-frequency switch tube S2H, the fifth high-frequency switch tube S3H and the seventh high-frequency switch tube S4H are all turned on. On the one hand, the first boost inductor L1 experiences a reverse voltage drop of (Vco1-Vcin1) and starts to discharge energy, and the current flowing through the first boost inductor gradually decreases; on the other hand, the third capacitor Co1 and the fourth capacitor Co2 supply energy to the filter unit through the second high-frequency switch tube S1L, the fifth high-frequency switch tube S3H and the first high-frequency transformer T1. The potential difference VNL between the input side positive voltage node N and the negative voltage node L of the filter unit is equal to- (Vco2+ Vcin1) — 1/2(Vco + Vcin), the voltage difference between the drain and the source of the first high-frequency switch tube S1H is equal to Vcin1+ Vco2, the voltage difference between the drain and the source of the fourth high-frequency switch tube S2L is equal to Vcin1+ Vco2, the voltage difference between the drain and the source of the sixth high-frequency switch tube S3L is equal to Vcin2+ Vco1, and the voltage difference between the drain and the source of the eighth high-frequency switch tube S4L is equal to Vcin2+ Vco 1.

Specifically, in the equivalent circuit diagram of the circuit shown in fig. 9 when the circuit operates in the fourth negative operating mode, as shown in fig. 12d, the second high-frequency switch tube S1L, the third high-frequency switch tube S2H, the sixth high-frequency switch tube S3L and the eighth high-frequency switch tube S4L are all turned on. On the one hand, the current output by the direct current power supply Uin charges the first boost inductor L1 through the third high-frequency switch tube S2H and the sixth high-frequency switch tube S3L, and charges the first boost inductor L1 through the third high-frequency switch tube S2H and the eighth high-frequency switch tube S4L by the second path, so that the first boost inductor L1 stores energy, and the current flowing through the first boost inductor L1 gradually rises; on the other hand, the fourth capacitor Co2 and the second capacitor Cin2 supply energy to the filtering unit through the second high-frequency switch tube S1L, the sixth high-frequency switch tube S3L and the first high-frequency transformer T1. The potential difference VNL between the input side positive voltage node N and the negative voltage node L of the filter unit is equal to (Vcin2-Vin-Vco2) — 1/2(Vco + Vcin), the voltage difference between the drain and the source of the first high-frequency switch tube S1H is equal to Vcin1+ Vco2, the voltage difference between the drain and the source of the fourth high-frequency switch tube S2L is equal to Vcin1+ Vco2, the voltage difference between the drain and the source of the fifth high-frequency switch tube S3H is equal to Vcin2+ Vco1, and the voltage difference between the drain and the source of the seventh high-frequency switch tube S4H is equal to Vcin2+ Vco 1.

Specifically, in the equivalent circuit diagram of the circuit shown in fig. 9 when the circuit operates in the fifth negative operation mode, as shown in fig. 12e, the second high-frequency switch tube S1L, the fourth high-frequency switch tube S2L, the fifth high-frequency switch tube S3H and the eighth high-frequency switch tube S4L are all turned on. On the one hand, the first boost inductor L1 experiences a reverse voltage drop of (Vco2-Vcin2) and starts to discharge energy, and the current flowing through the first boost inductor gradually decreases; on the other hand, the third capacitor Co1 and the fourth capacitor Co2 supply energy to the filter unit through the second high-frequency switch tube S1L, the fifth high-frequency switch tube S3H and the first high-frequency transformer T1. The potential difference VNL between the input side positive voltage node N and the negative voltage node L of the filter unit is equal to- (Vco1+ Vcin2) — 1/2(Vco + Vcin), the voltage difference between the drain and the source of the first high-frequency switch tube S1H is equal to Vcin1+ Vco2, the voltage difference between the drain and the source of the third high-frequency switch tube S2H is equal to Vcin1+ Vco2, the voltage difference between the drain and the source of the sixth high-frequency switch tube S3L is equal to Vcin2+ Vco1, and the voltage of S4H is equal to Vcin2+ Vco 1.

Specifically, in the equivalent circuit diagram of the circuit shown in fig. 9 when the circuit operates in the sixth negative operating mode, as shown in fig. 12f, the first high-frequency switch tube S1H, the third high-frequency switch tube S2H, the fifth high-frequency switch tube S3H and the seventh high-frequency switch tube S4H are all turned on. On the one hand, the first boost inductor L1 experiences a reverse voltage drop of (Vco1-Vcin1) and starts to discharge energy, and the current flowing through the first boost inductor gradually decreases; on the other hand, the third capacitor Co1 and the first capacitor Cin1 supply energy to the filtering unit through the third high-frequency switch tube S2H, the seventh high-frequency switch tube S4H and the second high-frequency transformer T2. The potential difference VNL between the input side positive voltage node N and the negative voltage node L of the filter unit is equal to 0, the voltage of the second high-frequency switch tube S1L is equal to Vcin1+ Vco2, the voltage difference between the drain and the source of S2L is equal to Vcin1+ Vco2, the voltage difference between the drain and the source of the sixth high-frequency switch tube S3L is equal to Vcin2+ Vco1, and the voltage difference between the drain and the source of the eighth high-frequency switch tube S4L is equal to Vcin2+ Vco 1.

Specifically, in the equivalent circuit diagram of the circuit shown in fig. 9 when the circuit operates in the seventh negative operating mode, as shown in fig. 12g, the second high-frequency switch tube S1L, the fourth high-frequency switch tube S2L, the sixth high-frequency switch tube S3L and the eighth high-frequency switch tube S4L are all turned on. On the one hand, the first boost inductor L1 experiences a reverse voltage drop of (Vco2-Vcin2) and starts to discharge energy, and the current flowing through the first boost inductor gradually decreases; on the other hand, the fourth capacitor Co2 and the second capacitor Cin2 supply energy to the filtering unit through the fourth high-frequency switch tube S2L, the eighth high-frequency switch tube S4L and the second high-frequency transformer T2. The potential difference between the positive voltage node N and the negative voltage node L on the input side of the filtering unit is equal to Vcin1+ Vco2, the voltage difference between the drain and the source of the third high-frequency switch tube S2H is equal to Vcin1+ Vco2, the voltage difference between the drain and the source of the fifth high-frequency switch tube S3H is equal to Vcin2+ Vco1, and the voltage difference between the drain and the source of the seventh high-frequency switch tube S4H is equal to Vcin2+ Vco 1.

In summary, when the modulation wave is in the sine negative half cycle, the single-stage boost inverter circuit mainly works in the seven working modes, so as to uninterruptedly convert the input direct current into the preset boost alternating current, and output the preset boost alternating current to the subsequent-stage load. At the time of sinusoidal negative half cycle, the potential difference VNL of the positive voltage node N and the negative voltage node L at the input side of the filter unit has three levels of-1/2 (Vco + Vcin), - (Vco + Vcin), and 0.

Therefore, no matter what state the single-stage boost inverter circuit works in, the voltage stress Vstress respectively borne by the upper switch tube and the lower switch tube in each half-bridge module is half of the sum of the input voltage and the output voltage, that is, Vstress is 1/2(Vco + Vin), the absolute values of the potential difference VNL between the positive voltage node N and the negative voltage node L on the input side of the filter unit are 1/2(Vco + Vcin), (Vco + Vcin) and 0, that is, the circuit realizes the output voltage three-level function. In addition, the current ripple frequency of the first boost inductor L1 and the current ripple frequency of the filter inductor in the filter unit are both 2 times the frequency of the first carrier input signal Vtri1 (or the second carrier input signal Vtri 2).

Further, in an embodiment of the present application, the half-bridge module in the single-stage boost inverter circuit includes two high-frequency switching tubes, which are a top tube SnH and a bottom tube SnL (n is 1,2,3, 4). In some embodiments, the upper tube SnH and the lower tube SnL are encased within a single package. Referring to fig. 13, the upper tube SnH is mounted in the first package, the lower tube SnL is mounted in the second package, and the first package and the second package may be disposed on the base 40 in an insulating and isolating manner. The drain electrode 43' of the lower tube SnL is electrically connected to a conductive structure portion of the first package, e.g. the submount 40, and may alternatively also be electrically connected to the drain lead 103, such as by a conductive bond wire 31. The gate 41 of the top tube SnH is electrically connected to the gate lead 102, for example, by a conductive bond wire 32. The gate electrode 41' of the lower tube SnL may be electrically connected to the conductive lead 101, such as by a conductive bond wire 33. The drain electrode 43 of the top tube SnH is electrically connected to the source electrode 42' of the bottom tube SnL, such as by a conductive bond wire 34. One or both of the drain electrode 43 of the top tube SnH and the source electrode 42 'of the bottom tube SnL may be bonded, such as by electrode wires, to the intermediate lead, for example the source electrode 42' of the top tube SnH is electrically connected to the intermediate lead 104 by a conductive bond wire 35. The source electrode 42 of the top tube SnH is electrically connected to a source lead 105, such as by a conductive bond wire 36.

Further, in one embodiment of the present application, the upper and lower tubes SnH, SnL (N is 1,2,3,4) in the input inverter bridge module and the output inverter bridge module are both III-N transistors, which may be, for example, Field Effect Transistors (FETs), High Electron Mobility Transistors (HEMTs), Heterojunction Field Effect Transistors (HFETs), POLFETs, JFETs, MESFETs, CAVETs, or any other III-N transistor structure suitable for power switching applications.

Further, in one embodiment of the present application, the III-N transistor is an enhancement mode (E-type) device, as shown in fig. 14a, i.e., a normally off device, such that the threshold voltage is greater than 0V, e.g., about 1.5V-2V or greater than 2V, and the enhancement mode (E-type) device is employed without a reverse body diode, which reduces the conduction loss of the single-stage boost inverter circuit when the device freewheels in the reverse direction. In other embodiments of the present application, the III-N transistor is formed by cascading a high voltage III-N depletion mode (D-mode) transistor and a low voltage enhancement mode (E-mode) transistor, connected as shown in fig. 14b, the depletion mode (D-mode) device, i.e., a normally-on device, such that the threshold voltage is less than 0V, and the low voltage enhancement mode (E-mode) transistor may be a low voltage SiMOS device, and in some embodiments of the present application, the III-N transistor further includes an external reverse parallel diode for reducing the device reverse recovery loss, as shown in fig. 14 c.

Further, in one embodiment of the present application, the III-N transistor is a high voltage switching transistor. As used herein, a high voltage switching transistor is a transistor optimized for high voltage switching applications. That is, when the transistor is off, it is able to block high voltages, such as about 300V, or more about 600V, or more about 1200V, or more, and when the transistor is on, it has a sufficiently low on-resistance (Rdson) for the above-mentioned applications, i.e., when a large amount of current is passed through the device, a lower on-loss is achieved.

Further, in one embodiment of the present application, the first and second anti-reflux modules in the single-stage boost inverter circuit are both III-N rectifying devices, which may be at least two lateral III-N diodes having an insulating or semi-insulating portion on opposite sides of the semiconductor body with respect to all electrodes, such as the III-N diodes shown in fig. 15. The III-N diode in fig. 15 includes an insulating or semi-insulating portion 61, a III-N buffer layer 63 (such as GaN), and a III-N barrier layer 64 (such as AlGaN), a semiconductor body 62 of a two-dimensional electron gas (2DEG) channel 65, an anode contact 28 that contacts the semiconductor body 62 on opposite sides of the insulating or semi-insulating portion 61 and forms a schottky contact with the semiconductor material of the semiconductor body 62, and a cathode contact 29 that forms an ohmic contact with the 2DEG channel 65. The III-N diode may optionally include a conductive or semiconductive portion 66, such as a silicon substrate.

Further, in one embodiment of the present application, the III-N diodes in the III-N rectifying device may be connected in a common anode manner, as shown in fig. 16a, or in a common cathode manner, as shown in fig. 16 b.

Further, in one embodiment of the present application, the III-N rectifying device is formed by two independently packaged III-N diodes, which are illustrated in fig. 17a, and through external electrical connections, the independently packaged III-N diodes are illustrated in fig. 17a, and fig. 17a illustrates portions of the package and the electronic device packaged or encapsulated in the package. Wherein the electronic component 90 comprises a single III-N diode 22 all encapsulated, wrapped or sealed in a separate package. The individual packages include a plurality of sealing structure portions, such as package base 94, and non-structure portions, such as first lead 91, second lead 92, and third lead 93. As used herein, a "structural portion" of a package is a portion that forms the basic shape or form of the package and provides the structural rigidity of the package required to protect the enclosed device. In most cases, when electronic components including packages are used in discrete circuits, the structural portions of the packages are mounted directly to the circuit or circuit board. In the stand-alone package of fig. 17a, the package base 94 is formed of an electrically conductive material, i.e. the package base 94 is an electrically conductive structural part of the package. The single package includes at least two pins, an anode pin 91 and a cathode pin 93, and optionally at least one other pin, such as an open pin 92. The anode lead 91, the open lead 92 and the cathode lead 93 are all formed of a conductive material. When open pin 92 is included, it may be electrically connected to package base 94 or electrically isolated from package base 94, with the other pins all electrically isolated from the package base. As used herein, two or more contacts or other items are said to be "electrically connected" if they are connected by a material that is sufficiently conductive to ensure that the potential at each of the contacts or other items is always the same, i.e., approximately the same, under any bias conditions.

When the III-N diode 22 is used in a III-N rectifying device, the III-N diode 22 is mounted inside a single package and connected as follows, which may be a first conductive bond wire 38, a second conductive bond wire 39 for electrically connecting portions of the package and the III-N diode 22 to each other. Wherein the respective insulating or semi-insulating substrates of III-N diode 22 are in contact with package base 94. The cathode contact 29 of the III-N diode 22 is electrically connected to a conductive structural portion of the package, such as the package base 94, or may otherwise be electrically connected to the cathode lead 93 of the package, such as by the second conductive bond wire 39. The anode contact 28 of the III-N diode 22 is electrically connected to the anode lead 91 of the package, such as by a first electrically conductive bond wire 38.

Further, in one embodiment of the present application, the III-N rectifying device is a dual-barreled packaged III-N diode assembly, as shown in fig. 17b, which illustrates portions of the package and the electronic device encapsulated or encapsulated in the package in fig. 17 b. The electronic component 90 includes a III-N diode 22 and a III-N diode 22' both encapsulated, enveloped, or sealed in a dual tube package. The dual tube package includes a plurality of sealing structure portions, such as a package base 94, and non-structure portions, such as a first lead 91, a second lead 92, and a third lead 93. As used herein, a "structural portion" of a package is a portion that forms the basic shape or form of the package and provides the structural rigidity of the package required to protect the enclosed device. In most cases, when electronic components including packages are used in discrete circuits, the structural portions of the packages are mounted directly to the circuit or circuit board. In the dual tube package of fig. 17b, the package base 94 is formed of a conductive material, i.e. the package base 94 is a conductive structural part of the package. A single package includes at least three pins, an anode pin 91, a cathode pin 93, and a common cathode pin 92. Anode lead 91, cathode lead 93 and common cathode lead 92 are all formed of a conductive material. The common cathode lead 92 may be electrically connected to the package base 94 or electrically isolated from the package base 94, and all other leads are electrically isolated from the package base. As used herein, two or more contacts or other items are said to be "electrically connected" if they are connected by a material that is sufficiently conductive to ensure that the potential at each of the contacts or other items is always the same, i.e., approximately the same, under any bias conditions.

Specifically, with continued reference to fig. 17b, when a III-N diode is used in a III-N rectifying device, the III-N diode 22 and the III-N diode 22 ' are mounted inside a dual-barreled package and connected as follows, a first conductive bond wire 38, a second conductive bond wire 38 ', and a third conductive bond wire 39 may be used to electrically connect portions of the package, the III-N diode 22, and the III-N diode 22 ' to one another. Wherein the respective insulating or semi-insulating substrates of III-N diode 22 and III-N diode 22' are in contact with package base 94. The cathode contact 29 of the III-N diode 22 and the cathode contact 29 'of the III-N diode 22' are electrically connected to a conductive structural portion of the package, such as the package base 94, and are additionally electrically connected to the common cathode lead 92 of the package by a third conductive bond wire 39. The anode contact 28 of the III-N diode 22 is electrically connected to the package anode lead 91, such as by a first electrically conductive bond wire 38, and the anode contact 28 ' of the III-N diode 22 ' is electrically connected to the package anode lead 93, such as by a second electrically conductive bond wire 38 '.

Referring to fig. 18a, fig. 18b and fig. 18c, in which fig. 18a shows the current ILin of the first boost inductor L of the single-stage boost inverter circuit and the first carrier input signal Vtri1, it can be seen that the ripple frequency of the current ILin of the inductor L is 2 times of the switching frequency. Therefore, compared with the traditional two-level inverter, the single-stage boosting inverter circuit can greatly reduce the size of the filter inductor under the same power level. Fig. 18b shows voltage stresses respectively borne by the terminal voltage Vco1 of the third capacitor Co1 and the terminal voltage Vco2 of the fourth capacitor Co2 of the single-stage boost inverter circuit, and the upper tube SnH and the lower tube SnL (n is 1,2,3,4) of the input inverter bridge module and the output inverter bridge module, which show that the maximum values of the voltage stresses of all the switching tubes are half of (Vco1+ Vco2), and satisfy the voltage stress characteristic of three levels. Fig. 18c shows the input voltage Vin of the input dc power source Uin of the single-stage boost inverter circuit, the terminal voltage of the load Rl is Vo, and the potential difference between the positive voltage node N and the negative voltage node L at the input side of the filtering unit is VNL.

Further, in an embodiment of the present application, there is provided a power conversion apparatus, including a single-stage boost inverter circuit as described in any of the embodiments of the present application, for converting an input dc power into a preset boost ac power.

Specifically, in the power conversion device in the above embodiment, the inductive energy storage backflow prevention unit is connected in series between the input inverter bridge module and the output inverter bridge module, and the capacitive energy storage unit is arranged to cooperate with the input inverter bridge module, the output inverter bridge module and the inductive energy storage backflow prevention unit to realize that the input direct current is inverted and boosted to the preset boost alternating current and then output to the next-stage load. Due to the cooperative action of the input inverter bridge module and the output inverter bridge module, the harmonic content in the voltage output to the next-stage load is effectively reduced, and the waveform quality can be improved while the volumes of the input filter element and the output filter element are reduced. Because the single-stage boost inverter circuit in the power conversion device provided by the application can convert the electric energy of a new energy power generation occasion into the electric energy by the original two-stage power conversion, the design cost of the power conversion device can be effectively reduced, and the cost performance and the integration level of the power conversion device are improved.

Further, in an embodiment of the present application, a single-stage boost inversion control method is provided, including:

step 202: generating an input inverter bridge control signal and an output inverter bridge control signal according to the first carrier input signal, the second carrier input signal and the first modulation wave input signal;

step 204: controlling the on-off of each switch unit in the input inverter bridge module based on the input inverter bridge control signal, and controlling the on-off of each switch unit in the output inverter bridge module based on the output inverter bridge control signal, so that the inductive energy storage anti-reflux unit outputs preset boosting alternating current to a next-stage load; the first port of the inductive energy storage backflow prevention unit is connected with the third port of the input inverter bridge module, the second port of the inductive energy storage backflow prevention unit is connected with the fourth port of the input inverter bridge module, the third port of the inductive energy storage backflow prevention unit is connected with the third port of the output inverter bridge module, and the fourth port of the inductive energy storage backflow prevention unit is connected with the fourth port of the output inverter bridge module; the first port of the input inverter bridge module is connected with the first port of the capacitive energy storage unit, the second port of the capacitive energy storage unit is connected with the second port of the input inverter bridge module, the third port of the capacitive energy storage unit is connected with the first port of the output inverter bridge module, the fourth port of the capacitive energy storage unit is connected with the second port of the output inverter bridge module, the first port of the input inverter bridge module is used for being connected with the positive output end of the direct-current power supply, and the fourth port of the capacitive energy storage unit is used for being connected with the negative output end of the direct-current power supply and the ground.

Specifically, in the single-stage boost inverting method in the above embodiment, the input inverter bridge control signal and the output inverter bridge control signal are generated according to the first carrier input signal, the second carrier input signal, and the first modulation wave input signal; and controlling the on-off of each switch unit in the input inverter bridge module based on the input inverter bridge control signal, and controlling the on-off of each switch unit in the output inverter bridge module based on the output inverter bridge control signal, so that the inductive energy storage anti-reflux unit outputs preset boosting alternating current to a next-stage load. The embodiment effectively reduces the harmonic content in the voltage output to the load of the next stage, and can improve the waveform quality while reducing the volumes of the input filter element and the output filter element.

For specific limitations of the single-stage boost inverting method in the above embodiments, reference may be made to the above limitations of the single-stage boost inverting circuit, and details are not repeated here.

It should be understood that the steps described are not to be performed in the exact order recited, and that the steps may be performed in other orders, unless explicitly stated otherwise. Moreover, at least some of the steps described may include multiple sub-steps or multiple stages that are not necessarily performed at the same time, but may be performed at different times, and the order of performing the sub-steps or stages is not necessarily sequential, but may be performed alternately or in alternation with other steps or at least some of the sub-steps or stages of other steps.

It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by hardware instructions of a computer program, which can be stored in a non-volatile computer-readable storage medium, and when executed, can include the processes of the embodiments of the methods described above. Any reference to memory, storage, database, or other medium used in the embodiments provided herein may include non-volatile and/or volatile memory, among others.

It should be noted that the above-mentioned embodiments are only for illustrative purposes and are not meant to limit the present invention.

The embodiments in the present specification are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the claims. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A single-stage boost inverter circuit, comprising:

an input inverter bridge module;

an output inverter bridge module;

2. The single-stage boost inverter circuit of claim 1, wherein the inductive energy storage anti-reflux unit comprises:

3. The single-stage boost inverter circuit of claim 2, wherein the first anti-backflow module comprises:

4. The single-stage boost inverter circuit of claim 2, wherein the second anti-backflow module comprises:

5. The single-stage boost inverter circuit according to any one of claims 1 to 4, wherein the capacitive energy storage unit comprises:

6. The single-stage boost inverter circuit of claim 5, wherein:

the input energy storage unit comprises a first capacitor and a second capacitor which are connected in series, wherein an input port of the first capacitor is connected with a first port of the input inverter bridge module, an output port of the second capacitor is connected with a second port of the output inverter bridge module, and an output port of the first capacitor is connected with a third port of the output energy storage unit; and/or

7. The single-stage boost inverter circuit according to any of claims 1-4, wherein said input inverter bridge module comprises:

8. The single-stage boost inverter circuit of claim 7, wherein:

the first upper bridge arm switch unit comprises a first high-frequency switch tube, and the drain electrode of the first high-frequency switch tube is connected with the first port of the capacitive energy storage unit;

9. The single-stage boost inverter circuit according to any of claims 1-4, wherein the output inverter bridge module comprises:

10. The single-stage boost inverter circuit of claim 9, wherein:

the third upper bridge arm switch unit comprises a fifth high-frequency switch tube, and the drain electrode of the fifth high-frequency switch tube is connected with the third port of the capacitive energy storage unit;

11. The single-stage boost inverter circuit according to any one of claims 1 to 4, further comprising:

12. The single-stage boost inverter circuit of claim 11, wherein:

the first electromagnetic isolation module comprises a first high-frequency transformer, a first port of the first high-frequency transformer is connected with a third port of the input inverter bridge module, and a second port of the first high-frequency transformer is connected with a third port of the output inverter bridge module; and/or

13. The single-stage boost inverter circuit of claim 12, further comprising:

and a first port of the filtering unit is connected with an output port of the first high-frequency transformer, and a second port of the filtering unit is connected with an output port of the second high-frequency transformer.

14. A power conversion apparatus, comprising:

a single stage boost inverter circuit as claimed in any one of claims 1 to 13 for converting an input dc power to a predetermined boost ac power.

15. A single-stage boosting inversion control method is characterized by comprising the following steps: