Boost inverter circuit and driving method
By employing a dual push-pull unit parallel design in the boost inverter circuit, the current stress is shared, solving the problems of conduction loss and safety hazards caused by excessive switching current in traditional inverter circuits under high-power applications, and achieving more efficient and reliable circuit operation.
Patent Information
- Application Number
- CN202610099786.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-23
- Publication Date
- 2026-05-01
AI Technical Summary
In high-power applications, traditional two-stage topologies require the switching transistors to withstand large currents, leading to increased conduction losses, overheating, overload, and safety hazards.
The boost inverter circuit adopts a dual push-pull unit parallel design. By connecting the first push-pull unit and the second push-pull unit in parallel, the current is shared, reducing the current stress on a single switch and reducing energy loss.
It reduces the conduction loss of the switching transistor, alleviates the heat load, improves the operating efficiency and stability of the circuit, and reduces safety hazards such as overload, short circuit and burnout.
Smart Images
Figure CN121966324A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of electronic technology, specifically to a boost inverter circuit and driving method. Background Technology
[0002] With societal development, the demand for mobile devices and energy storage equipment is increasing. Currently, energy storage inverter technology has particularly prominent shortcomings in high-power application scenarios. The traditional two-stage topology mainly consists of cascaded DC-DC converters, DC-AC converters, and high-frequency transformers. This scheme first converts the low-voltage DC power of the energy storage into high-voltage DC power through the DC-DC converter, and then the DC-AC converter converts it into industrial frequency AC power that can be used by electronic devices.
[0003] However, under high-power conditions, the switching transistors of traditional push-pull inverters need to withstand large currents, which directly leads to increased conduction losses and reduced overall operating efficiency. At the same time, large currents can easily cause the switching transistors to overheat and overload, which can lead to short circuits, burnout, and other risks, posing significant safety hazards. Summary of the Invention
[0004] This application provides a boost inverter circuit and driving method. By using a design of parallel dual push-pull units to share the current, the current stress of a single switch is reduced, energy loss under high-power applications is reduced, and the overall operating efficiency is improved.
[0005] The technical solution adopted by this invention to solve the problem is as follows: In a first aspect, embodiments of this application provide a boost inverter circuit, the boost inverter circuit comprising: A boost module includes a first push-pull unit and a second push-pull unit. The input terminals of the first push-pull unit and the second push-pull unit are connected in parallel to form a boost input terminal, which is used to connect to a DC power supply. The output terminals of the first push-pull unit and the second push-pull unit are connected in parallel to form a boost output terminal. The boost module is used to boost the first DC power from the DC power supply through the first push-pull unit and the second push-pull unit to output a second DC power. An inverter module is connected to the boost output terminal of the DC boost module. The inverter module is used to invert the second DC power to output the target AC power.
[0006] In some embodiments, the first push-pull unit includes a first transformer subunit, a first resonant subunit, and a first half-bridge rectifier subunit; the input terminal of the first transformer subunit is connected to the DC power supply, the output terminal of the first transformer subunit is connected to the first terminal of the first resonant subunit, the second terminal of the first resonant subunit is connected to the input terminal of the first half-bridge rectifier subunit, and the output terminal of the first half-bridge rectifier subunit is connected to the inverter module.
[0007] In some embodiments, the first transformer subunit includes a first transformer, a first switching transistor, and a second switching transistor; the center tap of the primary winding of the first transformer is used to connect to the DC power supply; the first end of the primary winding of the first transformer is connected to the first end of the first switching transistor; the second end of the primary winding of the first transformer is connected to the first end of the second switching transistor; the second end of the second switching transistor and the second end of the first switching transistor are connected and grounded; the first end of the secondary winding of the first transformer is connected to the first end of the first resonant subunit; and the second end of the secondary winding of the first transformer is connected to the first half-bridge rectifier subunit.
[0008] In some embodiments, the first resonator unit includes a first inductor; a first end of the first inductor is connected to the first transformer unit, and a second end of the first inductor is connected to the first half-bridge rectifier unit.
[0009] In some embodiments, the first half-bridge rectifier subunit includes a third switch, a fourth switch, a first capacitor, and a second capacitor; the first end of the third switch is connected to the first end of the first capacitor and the inverter module, the second end of the third switch is connected to the first end of the fourth switch and the first transformer subunit, the second end of the fourth switch is connected to the second end of the second capacitor and the inverter module, and the second end of the first capacitor is connected to the first end of the second capacitor and the second end of the first resonator subunit.
[0010] In some embodiments, the second push-pull unit includes a second transformer subunit, a second resonant subunit, and a second half-bridge rectifier subunit; the input terminal of the second transformer subunit is connected to the DC power supply, the output terminal of the second transformer subunit is connected to the first terminal of the second resonant subunit, the second terminal of the second resonant subunit is connected to the input terminal of the second half-bridge rectifier subunit, and the output terminal of the second half-bridge rectifier subunit is connected to the inverter module.
[0011] In some embodiments, the inverter module includes a ninth switch, a tenth switch, an eleventh switch, a twelfth switch, a third inductor, and a fifth capacitor; the first terminal of the ninth switch is connected to the first terminal of the eleventh switch and the boost output terminal; the second terminal of the ninth switch is connected to the first terminal of the tenth switch and the first terminal of the third inductor; the second terminal of the eleventh switch is connected to the first terminal of the twelfth switch and the second terminal of the fifth capacitor to form a second AC output terminal; the second terminal of the tenth switch is connected to the second terminal of the twelfth switch; and the second terminal of the third inductor is connected to the first terminal of the fifth capacitor to form a first AC output terminal. The first AC output terminal and the second AC output terminal are used as the output terminals of the target AC power.
[0012] Secondly, embodiments of this application provide a driving method applied to the boost inverter circuit described in any of the above embodiments. The first push-pull unit includes a first switch, a second switch, a third switch, and a fourth switch. One operating cycle of the boost module includes a first boost stage, a second boost stage, a third boost stage, and a fourth boost stage. The driving method includes: in the first boost stage, controlling the second switch and the third switch to turn off, and controlling the first switch and the fourth switch to turn on; in the second boost stage, controlling the first switch, the second switch, the third switch, and the fourth switch to all turn off; in the third boost stage, controlling the first switch and the fourth switch to turn off, and controlling the second switch and the third switch to turn on; in the fourth boost stage, controlling the first switch, the second switch, the third switch, and the fourth switch to all turn off.
[0013] In some embodiments, the second push-pull unit includes a fifth switch, a sixth switch, a seventh switch, and an eighth switch. The driving method further includes: in the first boost phase, controlling the sixth switch and the seventh switch to turn off, and controlling the fifth switch and the eighth switch to turn on; in the second boost phase, controlling the fifth switch, the sixth switch, the seventh switch, and the eighth switch to all turn off; in the third boost phase, controlling the fifth switch and the eighth switch to turn off, and controlling the sixth switch and the seventh switch to turn on; and in the fourth boost phase, controlling the fifth switch, the sixth switch, the seventh switch, and the eighth switch to all turn off.
[0014] In some embodiments, the inverter module includes a ninth switch, a tenth switch, an eleventh switch, and a twelfth switch. One operating cycle of the inverter module includes a first inverter stage and a second inverter stage. The driving method further includes: in the first inverter stage, controlling the ninth switch and the twelfth switch to be turned on, and controlling the tenth switch and the eleventh switch to be turned off; in the second inverter stage, controlling the tenth switch and the eleventh switch to be turned on, and controlling the ninth switch and the twelfth switch to be turned off.
[0015] This application provides a boost inverter circuit and a driving method. Specifically, the boost inverter circuit includes a boost module and an inverter module, and the boost module includes a first push-pull unit and a second push-pull unit. By using the first and second push-pull units connected in parallel in the boost module, the current flowing through a single push-pull unit under high-power conditions is distributed, thereby reducing the current stress on the switching transistors. This reduces the conduction losses of the switching transistors and improves the overall circuit efficiency. Simultaneously, the reduced current stress also alleviates the heat load on the switching transistors, reducing safety hazards such as overload, short circuit, and burnout, and improving the stability and reliability of the circuit under high-power output. Attached Figure Description
[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0017] Figure 1 This is a structural block diagram of a boost inverter circuit provided in an embodiment of the present invention; Figure 2 This is a structural block diagram of a first push-pull unit provided in an embodiment of the present invention; Figure 3 This is a structural block diagram of the second push-pull unit provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the circuit structure of a boost module provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the circuit structure of an inverter module provided in an embodiment of the present invention; Figure 6 This is a flowchart illustrating a driving method provided in an embodiment of the present invention; Figure 7 This is a waveform diagram of the first push-pull unit during operation according to an embodiment of the present invention; Figure 8This is a waveform diagram of the inverter module during operation according to an embodiment of the present invention. Detailed Implementation
[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0019] In the description of this application, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," "third," etc., may explicitly or implicitly include one or more features.
[0020] In this application, the term "exemplary" is used to mean "used as an example, illustration, or description." Any embodiment described as "exemplary" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use this application. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that this application can be made without using these specific details. In other instances, well-known structures and processes are not described in detail to avoid obscuring the description of this application with unnecessary detail. Therefore, this application is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.
[0021] It should be noted that since the method in this application embodiment is executed in a computer device, the processing objects of each computer device exist in the form of data or information, such as time, which is essentially time information. It is understood that if size, quantity, position, etc. are mentioned in subsequent embodiments, they are all corresponding data that exist so that the computer device can process them. Specific details will not be elaborated here.
[0022] In a first aspect, embodiments of this application provide a boost inverter circuit 100, such as... Figure 1As shown, the boost inverter circuit 100 includes a boost module 10 and an inverter module 20. The boost module 10 includes a first push-pull unit 11 and a second push-pull unit 12. The input terminals of the first push-pull unit 11 and the second push-pull unit 12 are connected in parallel to form a boost input terminal, which is used to connect to the DC power supply Vdc. The output terminals of the first push-pull unit 11 and the second push-pull unit 12 are connected in parallel to form a boost output terminal. The inverter module 20 is connected to the boost output terminal of the DC boost module 10. Specifically, the boost module 10 is used to boost the first DC power supply Vdc through the first push-pull unit 11 and the second push-pull unit 12 to output a second DC power supply. The inverter module 20 is used to invert the second DC power supply to output a target AC power supply U0.
[0023] The DC power supply Vdc provides stable DC power, such as from battery packs or solar panels. The first DC power is the raw low-voltage DC power provided by Vdc, such as 48V. The second DC power is the high-voltage DC power output after processing by the boost module 10, such as 360V. The target AC power is the AC power output from the inverter module 20 that meets the load requirements, such as 220V.
[0024] The boost module 10 is used to receive the first DC power from the DC power supply Vdc and boost its voltage to a preset higher DC voltage level.
[0025] The first push-pull unit 11 and the second push-pull unit 12 are power conversion structures in the boost module 10, typically composed of switching devices and transformers, used to boost the first DC current. These two units work in parallel to jointly undertake the boost task, thereby distributing current stress.
[0026] Inverter module 20 is used to convert the second DC power output from boost module 10 into the target AC power.
[0027] In this embodiment, by employing a first push-pull unit 11 and a second push-pull unit 12 connected in parallel within the boost module 10, the current flowing through a single push-pull unit under high-power conditions is dispersed, thereby reducing the current stress on the switching transistor. This reduces the conduction loss of the switching transistor and improves the overall circuit efficiency. Simultaneously, the reduced current stress also alleviates the heat load on the switching transistor, reducing safety hazards such as overload, short circuit, and burnout, and improving the stability and reliability of the circuit under high-power output.
[0028] In some embodiments, such as Figure 2As shown, the first push-pull unit 11 includes a first transformer subunit 111, a first resonant subunit 112, and a first half-bridge rectifier subunit 113. The input terminal of the first transformer subunit 111 is connected to a DC power supply Vdc, the output terminal of the first transformer subunit 111 is connected to the first terminal of the first resonant subunit 112, the second terminal of the first resonant subunit 112 is connected to the input terminal of the first half-bridge rectifier subunit 113, and the output terminal of the first half-bridge rectifier subunit 113 is connected to the inverter module 20.
[0029] The first transformer subunit 111 is used to boost and electrically isolate the DC voltage. It typically consists of one or more transformers, which transform the DC power supply voltage by adjusting the transformer's turns ratio and provide electrical isolation between the primary and secondary sides to enhance system safety.
[0030] The first resonant element 112 is used to introduce resonant characteristics during power conversion to achieve soft switching of the switching transistor, thereby reducing switching losses and improving the overall efficiency of the boost conversion. This element can be composed of an inductor, a capacitor, or a combination of both; for example, it can contain one or more inductor elements.
[0031] The first half-bridge rectifier subunit 113 is used to convert the AC power output from the first transformer subunit 111 into DC power, providing a stable, high-voltage DC input for the subsequent inverter module 20. This unit can be composed of rectifier diodes or switching transistors; for example, a half-bridge topology can be used to convert AC power into DC power.
[0032] In this embodiment, the first transformer subunit 111 achieves voltage boosting and electrical isolation, enhancing the system's safety and applicability. The introduction of the first resonant subunit 112 facilitates soft switching, reducing switching losses and thus improving the overall efficiency and reliability of the boost conversion. The first half-bridge rectifier subunit 113 converts high-frequency AC power into stable DC power, providing power input to the inverter module 20. This design makes the boost process more stable and controllable, reduces switching losses, and improves circuit efficiency.
[0033] In some embodiments, such as Figure 3 As shown, the second push-pull unit 12 includes a second transformer subunit 121, a second resonant subunit 122, and a second half-bridge rectifier subunit 123. The input terminal of the second transformer subunit 121 is connected to a DC power supply Vdc, the output terminal of the second transformer subunit 121 is connected to the first terminal of the second resonant subunit 122, the second terminal of the second resonant subunit 122 is connected to the input terminal of the second half-bridge rectifier subunit 123, and the output terminal of the second half-bridge rectifier subunit 123 is connected to the inverter module 20.
[0034] The second transformer subunit 121 is used to boost and electrically isolate the DC voltage. It typically consists of one or more transformers, which transform the DC power supply voltage by adjusting the transformer's turns ratio and provide electrical isolation between the primary and secondary sides to enhance system safety.
[0035] The second resonant element 122 is used to introduce resonant characteristics during power conversion to achieve soft switching of the switching transistor, thereby reducing switching losses and improving the overall efficiency of the boost conversion. This element can be composed of an inductor, a capacitor, or a combination of both; for example, it can contain one or more inductor elements.
[0036] The second half-bridge rectifier subunit 123 is used to convert the AC power output from the second transformer subunit 121 into DC power, providing a stable, high-voltage DC input for the subsequent inverter module 20. This unit can be composed of rectifier diodes or switching transistors; for example, a half-bridge topology can be used to convert AC power into DC power.
[0037] In this embodiment, the second transformer subunit 121 achieves voltage boosting and electrical isolation, enhancing the system's safety and applicability. The introduction of the second resonant subunit 122 facilitates soft switching, reducing switching losses and thus improving the overall boost conversion efficiency and reliability. The second half-bridge rectifier subunit 123 converts high-frequency AC power into stable DC power, providing power input to the inverter module 20. This design makes the boost process more stable and controllable, reduces switching losses, and improves circuit efficiency. Simultaneously, in the boost module 10, the second push-pull unit 12 operates in parallel with the first push-pull unit 11, enabling the output of boosted DC power, thereby improving the circuit's power handling capacity and overall conversion efficiency, and providing DC input to the inverter module 20. Furthermore, the parallel operation of the second push-pull unit 12 and the first push-pull unit 11 can share the current flowing through a single push-pull unit, thereby reducing the current stress on the switching transistors in a single push-pull unit and improving circuit stability and reliability.
[0038] In some embodiments, such as Figure 4 As shown, the first transformer subunit 111 includes a first transformer T1, a first switching transistor Q1, and a second switching transistor Q2. The center tap of the primary winding of the first transformer T1 is connected to a DC power supply Vdc. The first end of the primary winding of the first transformer T1 is connected to the first end of the first switching transistor Q1. The second end of the primary winding of the first transformer T1 is connected to the first end of the second switching transistor Q2. The second end of the second switching transistor Q2 and the second end of the first switching transistor Q1 are connected and grounded. The first end of the secondary winding of the first transformer T1 is connected to the first end of the first resonant subunit 112. The second end of the secondary winding of the first transformer T1 is connected to the first half-bridge rectifier subunit 113.
[0039] The first transformer T1 is mainly used for power isolation and voltage transformation. The first transformer T1 has a primary winding with a center tap. By alternately switching on the first switch Q1 and the second switch Q2, an alternating voltage is generated across the primary winding of the first transformer T1, thereby inducing the required voltage in the secondary winding.
[0040] The first switch Q1 and the second switch Q2 are switching devices used to control the current flow. The first switch Q1 and the second switch Q2 alternately turn on and off. By controlling the duty cycle and frequency of their drive signals, a symmetrical (opposite polarity and same magnitude) square wave voltage can be generated on the primary winding of the first transformer T1, thereby achieving effective chopping and energy transfer of the DC power supply Vdc. The two switches work together to ensure that the current flows alternately on the primary side of the first transformer T1, forming a push-pull working mode.
[0041] In this embodiment, the first switch Q1 and the second switch Q2 are PMOS transistors. The source of the PMOS transistor is the first terminal of the first switch Q1, the drain of the PMOS transistor is the second terminal of the first switch Q1, and the gate of the PMOS transistor is the controlled terminal of the first switch Q1. The second switch Q2 is similar to the first switch Q1. Alternatively, the first switch Q1 and the second switch Q2 can be any controllable switch, such as an Insulated Gate Bipolar Transistor (IGBT), an Integrated Gate-Commutated Thyristor (IGCT), a Gate-Turn-Off Thyristor (GTO), a Silicon Controlled Rectifier (SCR), a Junction Field-Effect Transistor (JFET), or a MOS Controlled Thyristor (MCT), etc.
[0042] In this embodiment, a first transformer sub-unit 111 is constructed using a first transformer T1, a first switch Q1, and a second switch Q2, and is connected to a DC power supply Vdc via a center tap, realizing push-pull primary-side drive. Through the alternating switching actions of the first switch Q1 and the second switch Q2, the DC power supply Vdc can be chopped into a high-frequency AC signal under lower voltage stress, thereby improving energy conversion efficiency and reducing switching losses, thus enhancing the overall performance and reliability of the entire boost inverter circuit.
[0043] In some embodiments, the first resonator unit 112 includes a first inductor L1. A first end of the first inductor L1 is connected to a first transformer subunit 111, and a second end of the first inductor L1 is connected to a first half-bridge rectifier subunit 113.
[0044] The primary function of the first inductor L1 is as an energy storage element and a resonant element.
[0045] In practical applications, the first inductor L1 can store electrical energy and form a resonant circuit with other capacitive components in the circuit (such as the first capacitor C1 and the second capacitor C2 described below). Its current drops to zero before the switching transistor is turned off, achieving soft switching, reducing switching losses, and improving overall conversion efficiency. Furthermore, the presence of the first inductor L1 can filter the current output from the first transformer subunit 111, providing a smoother and more optimized input to the first half-bridge rectifier subunit 113, thereby reducing losses during rectification and improving the quality of the output DC power.
[0046] In some embodiments, the first half-bridge rectifier subunit 113 includes a third switch Q3, a fourth switch Q4, a first capacitor C1, and a second capacitor C2. The first terminal of the third switch Q3 is connected to the first terminal of the first capacitor C1 and the inverter module 20; the second terminal of the third switch Q3 is connected to the first terminal of the fourth switch Q4 and the first transformer subunit 111; the second terminal of the fourth switch Q4 is connected to the second terminal of the second capacitor C2 and the inverter module 20; and the second terminal of the first capacitor C1 is connected to the first terminal of the second capacitor C2 and the second terminal of the first resonant subunit 112.
[0047] Among them, the third switch Q3 and the fourth switch Q4 are switching devices used to control the current flow.
[0048] The first capacitor C1 and the second capacitor C2 are energy storage elements, usually electrolytic capacitors or ceramic capacitors, mainly used for filtering and stabilizing DC output voltage.
[0049] In this embodiment, PMOS transistors are used as examples of the third switch Q3 and the fourth switch Q4. The drain of the PMOS transistor is the first terminal of the third switch Q3, the source is the second terminal, and the gate is the controlled terminal. The fourth switch Q4 is similar to the third switch Q3. However, the third switch Q3 and the fourth switch Q4 can be any controllable switch, such as an insulated-gate bipolar transistor (IGBT), an integrated gate-commutated thyristor (ICB), a gate-turn-off thyristor (GRT), a silicon controlled rectifier (SCR), a junction-gate field-effect transistor (JGFET), or a MOS-controlled thyristor.
[0050] In practical applications, the working principle of the first half-bridge rectifier subunit 113 relies on the coordinated operation of the third switch Q3, the fourth switch Q4, the first capacitor C1, and the second capacitor C2 to achieve the rectification and voltage multiplication functions of the AC power output from the first transformer subunit 111. When the AC power output from the first transformer subunit 111 is in the positive half-cycle (the first switch Q1 is on, and the second switch Q2 is off), the fourth switch Q4 is on and the third switch Q3 is off. The current flows through the fourth switch Q4 to charge the first capacitor C1, thus establishing a stable voltage across the first capacitor C1. When the AC power output from the first transformer subunit 111 is in the negative half-cycle (the first switch Q1 is off, and the second switch Q2 is on), the third switch Q3 is on and the fourth switch Q4 is off. The current flows through the third switch Q3 to charge the second capacitor C2, thus establishing a stable voltage across the second capacitor C2. Since the first capacitor C1 and the second capacitor C2 are connected in series, the DC bus voltage output by the first half-bridge rectifier subunit 113 is the sum of the voltages of the first capacitor C1 and the second capacitor C2. Therefore, the first half-bridge rectifier subunit 113 not only performs AC-to-DC rectification but also achieves voltage multiplication, providing the required high-voltage DC power to the subsequent inverter module 20. Simultaneously, when the first push-pull unit 11 is operating, the secondary winding of the first transformer T1, the first inductor L1, the first capacitor C1, and the second capacitor C2 resonate, enabling the current to be reduced to zero between the turn-off of the third switch Q3 and the fourth switch Q4, i.e., achieving soft switching, thereby reducing switching losses and improving circuit conversion efficiency.
[0051] In some embodiments, such as Figure 4 As shown, the second transformer subunit 121 includes a second transformer T2, a fifth switch Q5, and a sixth switch Q6. The center tap of the primary winding of the second transformer T2 is connected to a DC power supply Vdc. The first end of the primary winding of the second transformer T2 is connected to the first end of the fifth switch Q5. The second end of the primary winding of the second transformer T2 is connected to the first end of the sixth switch Q6. The second ends of the sixth switch Q6 and the fifth switch Q5 are connected and grounded. The first end of the secondary winding of the second transformer T2 is connected to the first end of the second resonant subunit 122. The second end of the secondary winding of the second transformer T2 is connected to the second half-bridge rectifier subunit 123.
[0052] In this embodiment, the fifth switch Q5 and the sixth switch Q6 are PMOS transistors. The source of the PMOS transistor is the first terminal of the fifth switch Q5, the drain of the PMOS transistor is the second terminal of the fifth switch Q5, and the gate of the PMOS transistor is the controlled terminal of the fifth switch Q5. The sixth switch Q6 is similar to the fifth switch Q5. Alternatively, the fifth switch Q5 and the sixth switch Q6 can be any controllable switch, such as an insulated-gate bipolar transistor (IGBT), an integrated gate-commutated thyristor (GMT), a gate-turn-off thyristor (GRT), a silicon controlled rectifier (SCR), a junction-gate field-effect transistor (JGFET), or a MOS-controlled thyristor.
[0053] In some embodiments, the second resonator unit 122 includes a second inductor L2. A first end of the second inductor L2 is connected to the second transformer subunit 121, and a second end of the second inductor L2 is connected to the second half-bridge rectifier subunit 123.
[0054] In some embodiments, the second half-bridge rectifier subunit 123 includes a seventh switch Q7, an eighth switch Q8, a third capacitor C3, and a fourth capacitor C4. The first terminal of the seventh switch Q7 is connected to the first terminal of the third capacitor C3 and the inverter module 20; the second terminal of the seventh switch Q7 is connected to the first terminal of the eighth switch Q8 and the second transformer subunit 121; the second terminal of the eighth switch Q8 is connected to the second terminal of the fourth capacitor C4 and the inverter module 20; and the second terminal of the third capacitor C3 is connected to the first terminal of the fourth capacitor C4 and the second terminal of the second resonant subunit 122.
[0055] In this embodiment, the seventh switch Q7 and the eighth switch Q8 are PMOS transistors. The drain of the PMOS transistor is the first terminal of the seventh switch Q7, the source is the second terminal of the seventh switch Q7, and the gate is the controlled terminal of the seventh switch Q7. The eighth switch Q8 is similar to the seventh switch Q7. However, the seventh switch Q7 and the eighth switch Q8 can be any controllable switch, such as an insulated-gate bipolar transistor (IGBT), an integrated gate-commutated thyristor (GMT), a gate-turn-off thyristor (GRT), a silicon controlled rectifier (SCR), a junction-gate field-effect transistor (JGFET), or a MOS-controlled thyristor.
[0056] Specifically, the working principle of the second transformer sub-unit 121 is similar to that of the first transformer sub-unit 111, the working principle of the second resonant sub-unit 122 is similar to that of the first resonant sub-unit 112, and the working principle of the second half-bridge rectifier sub-unit 123 is similar to that of the first half-bridge rectifier sub-unit 113, which will not be elaborated here.
[0057] In some embodiments, such as Figure 4As shown, the boost module 10 also includes a sixth capacitor E1. The sixth capacitor E1 is connected in parallel to the boost output terminal of the boost module 10 and is used to filter and regulate the second DC power output by the boost module 10.
[0058] In some embodiments, such as Figure 5 As shown, the inverter module 20 includes a ninth switch Q9, a tenth switch Q10, an eleventh switch Q11, a twelfth switch Q12, a third inductor L3, and a fifth capacitor E2. The first terminal of the ninth switch Q9 is connected to the first terminal of the eleventh switch Q11 and the boost output terminal. The second terminal of the ninth switch Q9 is connected to the first terminal of the tenth switch Q10 and the first terminal of the third inductor L3. The second terminal of the eleventh switch Q11 is connected to the first terminal of the twelfth switch Q12 and the second terminal of the fifth capacitor E2 to form a second AC output terminal. The second terminal of the tenth switch Q10 is connected to the second terminal of the twelfth switch Q12. The second terminal of the third inductor L3 is connected to the first terminal of the fifth capacitor E2 to form a first AC output terminal. The first and second AC output terminals are used as the output terminals of the target AC current U0.
[0059] Among them, the ninth switch Q9, the tenth switch Q10, the eleventh switch Q11, and the twelfth switch Q12 are semiconductor devices used to control the current switching, usually MOSFETs or IGBTs.
[0060] In this embodiment, the ninth switch Q9, tenth switch Q10, eleventh switch Q11, and twelfth switch Q12 are NMOS transistors. The drain of the NMOS transistor is the first terminal of the ninth switch Q9, the source is the second terminal of the ninth switch Q9, and the gate is the controlled terminal of the ninth switch Q9. The tenth, eleventh, and twelfth switches Q10 and Q11 are similar to the ninth switch Q9. Alternatively, the ninth, tenth, eleventh, and twelfth switches Q9 can be any controllable switch, such as an insulated-gate bipolar transistor (IGBT), an integrated gate-commutated thyristor (ICB), a gate-turn-off thyristor (GRT), a silicon controlled rectifier (SCR), a junction-gate field-effect transistor (JGFET), or a MOS-controlled thyristor.
[0061] In this embodiment, the ninth switch Q9, the tenth switch Q10, the eleventh switch Q11, and the twelfth switch Q12 form a full-bridge inverter structure. By controlling the ninth switch Q9 and the tenth switch Q10 to alternately turn on and off, and the twelfth switch Q12 to turn on and off synchronously with the ninth switch Q9, and the eleventh switch Q11 to turn on and off synchronously with the tenth switch Q10, the polarity of the DC power is reversed, thereby generating AC voltage. Therefore, the inverter module 20 can convert the second DC power (e.g., 360V) output by the boost module 10 into the target AC power (e.g., 220V). The third inductor L3 and the fifth capacitor E2 together constitute the output filter circuit, which can filter out the high-frequency harmonic components generated during the inverter process, making the output target AC power waveform smoother and purer, reducing harmonic distortion, and improving power quality.
[0062] In summary, this application provides a boost inverter circuit 100, which includes a boost module 10 and an inverter module 20. The boost module 10 includes a first push-pull unit 11 and a second push-pull unit 12. By using the first push-pull unit 11 and the second push-pull unit 12 connected in parallel in the boost module 10, the current flowing through a single push-pull unit under high-power conditions is distributed, thereby reducing the current stress on the switching transistors. This reduces the conduction losses of the switching transistors and improves the overall circuit efficiency. Simultaneously, the reduced current stress also alleviates the heat load on the switching transistors, reducing safety hazards such as overload, short circuit, and burnout, and improving the stability and reliability of the circuit under high-power output.
[0063] Secondly, this application also provides a driving method applied to the boost inverter circuit 100 in any of the above embodiments. The first push-pull unit 11 includes a first switch Q1, a second switch Q2, a third switch Q3, and a fourth switch Q4. One operating cycle of the boost module 10 includes a first boost stage, a second boost stage, a third boost stage, and a fourth boost stage. Figure 6 As shown, the driving method includes the following steps S11, S13, S15, and S17: Step S11: In the first boost stage, control the second switch Q2 and the third switch Q3 to turn off, and control the first switch Q1 and the fourth switch Q4 to turn on.
[0064] Step S13: In the second boost stage, the first switch Q1, the second switch Q2, the third switch Q3 and the fourth switch Q4 are all turned off.
[0065] Step S15: In the third boost stage, control the first switch Q1 and the fourth switch Q4 to turn off, and control the second switch Q2 and the third switch Q3 to turn on.
[0066] Step S17: In the fourth boost stage, control the first switch Q1, the second switch Q2, the third switch Q3 and the fourth switch Q4 to be turned off.
[0067] The boost module 10 executes multiple working cycles during operation. Each working cycle includes four stages: the first boost stage, the second boost stage, the third boost stage, and the fourth boost stage. Each stage corresponds to a different combination of on and off states of the switching transistors in the boost module 10.
[0068] like Figure 7 As shown, the horizontal axis represents time, 0~t1 represents the first boost stage, t1~t2 represents the second boost stage, t2~t3 represents the third boost stage, and t3~t4 represents the fourth boost stage. g1,4 U represents the driving waveform of the first switch Q1 and the fourth switch Q4. g2,3 This represents the driving waveforms of the second switch Q2 and the third switch Q3, U. Q1 U represents the voltage waveform between the drain and source of the first switching transistor Q1. Q2 This represents the voltage waveform between the drain and source of the second switching transistor Q2, i Q This represents the current waveform flowing through the third switch Q3 or the fourth switch Q4. Q3 This represents the current waveform flowing through the third switch Q3, i Q4 This represents the current waveform flowing through the fourth switch, Q4.
[0069] Please refer to the following: Figure 4 and Figure 7 The working principle of the first push-pull unit 11 will be briefly explained below.
[0070] Specifically, in the first boost stage, the second switch Q2 and the third switch Q3 are turned off, while the first switch Q1 and the fourth switch Q4 are turned on. At this time, the current flowing to the primary winding N1 of the first transformer T1 increases, and the voltage across the primary winding N1 is the same as the DC power supply Vdc. According to the relationship between the transformer's terminals, the first capacitor C1 begins to charge, and the reverse voltage across the second switch Q2 is twice the voltage of the DC power supply Vdc. Simultaneously, the current in the fourth switch Q4 increases from 0 to a steady state, maintains this position for a certain period, and then gradually decreases back to 0, thus achieving soft switching.
[0071] During the second boost phase, the first switch Q1, the second switch Q2, the third switch Q3, and the fourth switch Q4 are all turned off. At this time, the dead time begins. The excitation effect of the primary winding N1 of the first transformer T1 disappears, and the reverse voltage across the first switch Q1 and the second switch Q2 is the same as the voltage of the DC power supply Vdc.
[0072] In the third boost stage, the first switch Q1 and the fourth switch Q4 are turned off, while the second switch Q2 and the third switch Q3 are turned on. At this time, the current flowing to the primary winding N2 of the first transformer T1 increases, and the voltage across the primary winding N2 is the same as the DC power supply Vdc. According to the relationship between the transformer's terminals, the second capacitor C2 begins to charge, and the reverse voltage across the first switch Q1 is twice the voltage of the DC power supply Vdc. Simultaneously, the current in the third switch Q3 increases from 0 to a steady state, maintains this position for a certain period, and then gradually decreases back to 0, achieving soft switching.
[0073] In the fourth boost stage, the first switch Q1, the second switch Q2, the third switch Q3, and the fourth switch Q4 are all turned off. At this time, the dead time begins. The excitation effect of the primary winding N2 of the first transformer T1 disappears, and the reverse voltage across the first switch Q1 and the second switch Q2 is the same as the voltage of the DC power supply Vdc. After the voltage stabilizes, the DC bus voltage of the first push-pull unit 11 is the sum of the voltages of the first capacitor C1 and the second capacitor C2.
[0074] In this embodiment, the boost module 10's operating cycle is divided into a first boost stage, a second boost stage, a third boost stage, and a fourth boost stage. The on / off state of the switching transistors in the first push-pull unit 11 is set for each stage to manage the boost process. Simultaneously, the switching transistors are turned off in both the second and fourth boost stages, introducing a dead time to prevent shoot-through. Furthermore, the current of the third switching transistor Q3 and the fourth switching transistor Q4 reaches zero before being turned off, achieving soft switching, reducing switching losses, and improving the operating efficiency and reliability of the boost module 10.
[0075] In some embodiments, the second push-pull unit 12 includes a fifth switch Q5, a sixth switch Q6, a seventh switch Q7, and an eighth switch Q8. The driving method further includes the following steps S12, S14, S16, and S18: Step S12: In the first boost stage, control the sixth switch Q6 and the seventh switch Q7 to turn off, and control the fifth switch Q5 and the eighth switch Q8 to turn on.
[0076] Step S14: In the second boost stage, control the fifth switch Q5, the sixth switch Q6, the seventh switch Q7 and the eighth switch Q8 to be turned off.
[0077] Step S16: In the third boost stage, control the fifth switch Q5 and the eighth switch Q8 to turn off, and control the sixth switch Q6 and the seventh switch Q7 to turn on.
[0078] Step S18: In the fourth boost stage, control the fifth switch Q5, the sixth switch Q6, the seventh switch Q7 and the eighth switch Q8 to be turned off.
[0079] The working principle of the second push-pull unit 12 is similar to that of the first push-pull unit 11. Please refer to [link / reference]. Figure 4 The working principle of the second push-pull unit 12 will be briefly explained below.
[0080] Specifically, in the first boost stage, the sixth switch Q6 and the seventh switch Q7 are turned off, while the fifth switch Q5 and the eighth switch Q8 are turned on. At this time, the current flowing to the primary winding N1 of the second transformer T2 increases, and the voltage across the primary winding N1 is the same as the DC power supply Vdc. According to the relationship between the transformer's terminals, the third capacitor C3 begins to charge, and the reverse voltage across the sixth switch Q6 is twice the voltage of the DC power supply Vdc. Simultaneously, the current in the eighth switch Q8 increases from 0 to a steady state, maintains this position for a certain period, and then gradually decreases back to 0, thus achieving soft switching.
[0081] During the second boost stage, the fifth switch Q5, the sixth switch Q6, the seventh switch Q7, and the eighth switch Q8 are all turned off. At this time, the dead time begins. The excitation effect of the primary winding N1 of the second transformer T2 disappears, and the reverse voltage across the fifth switch Q5 and the sixth switch Q6 is the same as the voltage of the DC power supply Vdc.
[0082] In the third boost stage, the fifth switch Q5 and the eighth switch Q8 are turned off, while the sixth switch Q6 and the seventh switch Q7 are turned on. At this time, the current flowing to the primary winding N2 of the second transformer T2 increases, and the voltage across the primary winding N2 is the same as the DC power supply Vdc. According to the relationship between the transformer's terminals, the fourth capacitor C4 begins to charge, and the reverse voltage across the fifth switch Q5 is twice the voltage of the DC power supply Vdc. Simultaneously, the current in the seventh switch Q7 increases from 0 to a steady state, maintains this position for a certain period, and then gradually decreases back to 0, achieving soft switching.
[0083] During the fourth boost stage, the fifth switch Q5, the sixth switch Q6, the seventh switch Q7, and the eighth switch Q8 are all turned off. At this time, the dead time begins. The excitation effect of the primary winding N2 of the second transformer T2 disappears, and the reverse voltage across the fifth switch Q5 and the sixth switch Q6 is the same as the voltage of the DC power supply Vdc. After the voltage stabilizes, the DC bus voltage of the second push-pull unit 12 is the sum of the voltages of the third capacitor C3 and the fourth capacitor C4.
[0084] In this embodiment, the on / off state of the switching transistors in the second push-pull unit 12 is set for each stage to manage the boost process. Simultaneously, the switching transistors are turned off in both the second and fourth boost stages, introducing a dead time to prevent shoot-through. Furthermore, the current of the seventh and eighth switching transistors Q7 and Q8 reaches zero before being turned off, achieving soft switching, reducing switching losses, and improving the operating efficiency and reliability of the boost module 10. Moreover, the coordinated operation of the first push-pull unit 11 and the second push-pull unit 12 in the boost module 10 can share the current, reducing the current stress on the switching transistors in a single push-pull unit compared to using a single push-pull unit for boost operation, thus reducing energy loss in high-power applications and improving overall operating efficiency.
[0085] In some embodiments, the inverter module 20 includes a ninth switch Q9, a tenth switch Q10, an eleventh switch Q11, and a twelfth switch Q12. One operating cycle of the inverter module 20 includes a first inverter stage and a second inverter stage. The driving method further includes the following steps S21 and S22: Step S21: In the first inverter stage, control the ninth switch Q9 and the twelfth switch Q12 to turn on, and control the tenth switch Q10 and the eleventh switch Q11 to turn off.
[0086] Step S22: In the second inverter stage, control the tenth switch Q10 and the eleventh switch Q11 to turn on, and control the ninth switch Q9 and the twelfth switch Q12 to turn off.
[0087] During operation, the inverter module 20 continuously executes multiple work cycles. Each work cycle includes two stages: a first inverter stage and a second inverter stage. Each stage corresponds to different on / off combinations of the switching transistors in the inverter module 20.
[0088] like Figure 8 As shown, the horizontal axis represents time, 0~t1 represents the first inverter stage, and t1~t2 represents the second inverter stage. g9,12 This represents the driving waveforms of the ninth switch Q9 and the twelfth switch Q12, U. g10,11 V0 represents the driving waveform of the tenth switch Q10 and the eleventh switch Q11, and V0 represents the voltage waveform of the target AC current U0.
[0089] Please refer to the following: Figure 5 and Figure 8 The working principle of inverter module 20 is briefly explained below.
[0090] Specifically, in the first inverter stage, the ninth switch Q9 and the twelfth switch Q12 are turned on, while the tenth switch Q10 and the eleventh switch Q11 are turned off. At this time, the output of the inverter module 20 is positive, which is the positive cycle of the target AC current U0.
[0091] Next, in the second inverter stage, the tenth switch Q10 and the eleventh switch Q11 are turned on, while the ninth switch Q9 and the twelfth switch Q12 are turned off. At this time, the output of the inverter module 20 is negative, which is the negative cycle of the target AC current U0. Through the alternation of the first and second inverter stages, the inverter module 20 can continuously output the complete AC current, that is, the target AC current U0.
[0092] In some embodiments, a dead time can be set between two consecutive operating cycles of the inverter module 20, and between the first inverter stage and the second inverter stage within an operating cycle. During this dead time, the ninth switch Q9, the tenth switch Q10, the eleventh switch Q11, and the twelfth switch Q12 are all turned off. This prevents shoot-through between two switches on the same bridge arm and improves circuit stability.
[0093] In this embodiment, the on / off state of the switching transistors in the inverter module 20 is set for each stage to manage the inverter process. Simultaneously, a dead time is introduced during switch switching to prevent the switching transistors from shooting through, thus improving circuit stability.
[0094] In summary, this application provides a driving method applied to a boost inverter circuit 100. By controlling the two push-pull units in the boost module 10 to work together, a first DC power (e.g., 48V) can be converted into a second DC power (e.g., 360V). Then, by controlling the operation of the inverter module 20, the second DC power can be converted into a target AC power (e.g., 220V). Ultimately, the boost and inversion of the first DC power supply Vdc to obtain the target AC power is achieved. During this process, the first push-pull unit 11 and the second push-pull unit 12 of the boost module 10 work together to share the current. Compared to using a single push-pull unit for boosting, this reduces the current stress on the switching transistors in a single push-pull unit, reduces energy loss in high-power applications, and improves overall operating efficiency. Furthermore, the rectifier switching transistors in the subsequent stage of the push-pull unit can achieve soft switching, reducing switching energy consumption and further improving operating efficiency.
[0095] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the detailed descriptions of other embodiments above, which will not be repeated here.
[0096] In practice, each of the above units or structures can be implemented as an independent entity or can be arbitrarily combined to be implemented as the same or several entities. For the specific implementation of each of the above units or structures, please refer to the previous method embodiments, which will not be repeated here.
[0097] For details on the implementation of each of the above operations, please refer to the previous examples, which will not be repeated here.
[0098] The above provides a detailed description of a boost inverter circuit and driving method provided in the embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.
Claims
1. A boost inverter circuit, characterized in that, The boost inverter circuit includes: A boost module includes a first push-pull unit and a second push-pull unit. The input terminals of the first push-pull unit and the second push-pull unit are connected in parallel to form a boost input terminal, which is used to connect to a DC power supply. The output terminals of the first push-pull unit and the second push-pull unit are connected in parallel to form a boost output terminal. The boost module is used to boost the first DC power from the DC power supply through the first push-pull unit and the second push-pull unit to output a second DC power. An inverter module is connected to the boost output terminal of the DC boost module. The inverter module is used to invert the second DC power to output the target AC power.
2. The boost inverter circuit according to claim 1, characterized in that, The first push-pull unit includes a first transformer subunit, a first resonator subunit, and a first half-bridge rectifier subunit; The input terminal of the first transformer subunit is connected to the DC power supply, the output terminal of the first transformer subunit is connected to the first terminal of the first resonant subunit, the second terminal of the first resonant subunit is connected to the input terminal of the first half-bridge rectifier subunit, and the output terminal of the first half-bridge rectifier subunit is connected to the inverter module.
3. The boost inverter circuit according to claim 2, characterized in that, The first transformer subunit includes a first transformer, a first switching transistor, and a second switching transistor; The center tap of the primary winding of the first transformer is used to connect to the DC power supply. The first end of the primary winding of the first transformer is connected to the first end of the first switching transistor. The second end of the primary winding of the first transformer is connected to the first end of the second switching transistor. The second end of the second switching transistor and the second end of the first switching transistor are connected and grounded. The first end of the secondary winding of the first transformer is connected to the first end of the first resonator unit. The second end of the secondary winding of the first transformer is connected to the first half-bridge rectifier unit.
4. The boost inverter circuit according to claim 2, characterized in that, The first resonator unit includes a first inductor; The first end of the first inductor is connected to the first transformer subunit, and the second end of the first inductor is connected to the first half-bridge rectifier subunit.
5. The boost inverter circuit according to claim 2, characterized in that, The first half-bridge rectifier subunit includes a third switch, a fourth switch, a first capacitor, and a second capacitor; The first end of the third switch is connected to the first end of the first capacitor and the inverter module; the second end of the third switch is connected to the first end of the fourth switch and the first transformer subunit; the second end of the fourth switch is connected to the second end of the second capacitor and the inverter module; and the second end of the first capacitor is connected to the first end of the second capacitor and the second end of the first resonator unit.
6. The boost inverter circuit according to claim 1, characterized in that, The second push-pull unit includes a second transformer subunit, a second resonator subunit, and a second half-bridge rectifier subunit; The input terminal of the second transformer subunit is connected to the DC power supply, the output terminal of the second transformer subunit is connected to the first terminal of the second resonant subunit, the second terminal of the second resonant subunit is connected to the input terminal of the second half-bridge rectifier subunit, and the output terminal of the second half-bridge rectifier subunit is connected to the inverter module.
7. The boost inverter circuit according to claim 1, characterized in that, The inverter module includes a ninth switch, a tenth switch, an eleventh switch, a twelfth switch, a third inductor, and a fifth capacitor; The first terminal of the ninth switch is connected to the first terminal of the eleventh switch and the boost output terminal. The second terminal of the ninth switch is connected to the first terminal of the tenth switch and the first terminal of the third inductor. The second terminal of the eleventh switch is connected to the first terminal of the twelfth switch and the second terminal of the fifth capacitor to form a second AC output terminal. The second terminal of the tenth switch is connected to the second terminal of the twelfth switch. The second terminal of the third inductor is connected to the first terminal of the fifth capacitor to form a first AC output terminal. The first AC output terminal and the second AC output terminal are used as the output terminals of the target AC power.
8. A driving method, characterized in that, Applied to the boost inverter circuit according to any one of claims 1 to 7, the first push-pull unit includes a first switch, a second switch, a third switch, and a fourth switch; one operating cycle of the boost module includes a first boost stage, a second boost stage, a third boost stage, and a fourth boost stage; the driving method includes: During the first boost phase, the second and third switching transistors are controlled to turn off, and the first and fourth switching transistors are controlled to turn on. During the second boost phase, the first switch, the second switch, the third switch, and the fourth switch are all turned off. In the third boost stage, the first and fourth switching transistors are turned off, and the second and third switching transistors are turned on. In the fourth boost phase, the first switch, the second switch, the third switch, and the fourth switch are all turned off.
9. The driving method according to claim 8, characterized in that, The second push-pull unit includes a fifth switch, a sixth switch, a seventh switch, and an eighth switch, and the driving method further includes: During the first boost phase, the sixth and seventh switches are controlled to turn off, and the fifth and eighth switches are controlled to turn on. During the second boost phase, the fifth, sixth, seventh, and eighth switching transistors are all turned off. In the third boost stage, the fifth and eighth switching transistors are controlled to turn off, and the sixth and seventh switching transistors are controlled to turn on. During the fourth boost phase, the fifth, sixth, seventh, and eighth switching transistors are all turned off.
10. The driving method according to claim 8, characterized in that, The inverter module includes a ninth switch, a tenth switch, an eleventh switch, and a twelfth switch. One operating cycle of the inverter module includes a first inverter stage and a second inverter stage. The driving method further includes: In the first inverter stage, the ninth and twelfth switches are controlled to be turned on, and the tenth and eleventh switches are controlled to be turned off. In the second inverter stage, the tenth and eleventh switches are turned on, and the ninth and twelfth switches are turned off.