Dc-ac conversion circuit and power conversion device

Abstract

The application relates to a direct-current alternating-current conversion circuit and a power conversion device. The direct-current alternating-current conversion circuit comprises: a plurality of direct-current side conversion circuits; a plurality of direct-current side windings, each direct-current side conversion circuit being connected with each direct-current side winding; and a controller, switch tubes located at the same topological position in each direct-current side conversion circuit being connected to the same driving output end of the controller. The direct-current alternating-current conversion circuit can make the chip area of the controller relatively small.

Description

Technical Field

[0001] This application relates to the field of power conversion technology, and in particular to a DC-AC conversion circuit and a power conversion device. Background Technology

[0002] In related technologies, when the DC side of a DC-AC converter circuit includes multiple parallel converter circuits, the number of switching transistors on the DC side is relatively large. The drive signal of each switching transistor needs to occupy one drive output terminal of the controller. Therefore, in this scenario, a controller with more I / O (Input / Output) pins is required, resulting in a larger chip area for the controller. Utility Model Content

[0003] Therefore, it is necessary to provide a DC-AC conversion circuit and power conversion device that minimizes the area of ​​the controller chip, addressing the aforementioned technical problems.

[0004] Firstly, a DC-AC converter circuit is provided, the DC-AC converter circuit comprising:

[0005] Multiple DC-side conversion circuits;

[0006] Multiple DC-side windings, with each DC-side conversion circuit connected to its respective DC-side winding;

[0007] The controller connects the switching transistors located in the same topology position in each DC-side conversion circuit to the same drive output terminal of the controller.

[0008] In one embodiment, the DC-AC converter circuit includes:

[0009] Multiple DC-side drivers are used, and the switching transistors located in the same topology position in each DC-side conversion circuit are connected to the same drive output terminal of the controller through different DC-side drivers.

[0010] In one embodiment, the DC-side driver includes two drive input terminals and two drive output terminals;

[0011] The first bridge arm circuit of each DC-side converter circuit includes a first switching transistor and a second switching transistor, and each first bridge arm circuit corresponds to a DC-side driver.

[0012] The first drive output terminal of the DC-side driver corresponding to each first bridge arm circuit is connected to each first switch transistor, and the second drive output terminal of the DC-side driver corresponding to each first bridge arm circuit is connected to each second switch transistor.

[0013] The first drive input terminal of the DC-side driver corresponding to each first bridge arm circuit is connected to the first drive output terminal of the controller, and the second drive input terminal of the DC-side driver corresponding to each first bridge arm circuit is connected to the second drive output terminal of the controller.

[0014] In one embodiment, the second bridge arm circuit of each DC-side converter circuit includes a third switch and a fourth switch, and each second bridge arm circuit corresponds to a DC-side driver.

[0015] The first drive output terminal of the DC-side driver corresponding to each second bridge arm circuit is connected to each third switch, and the second drive output terminal of the DC-side driver corresponding to each second bridge arm circuit is connected to each fourth switch.

[0016] The first drive input terminal of the DC-side driver corresponding to each second bridge arm circuit is connected to the third drive output terminal of the controller, and the second drive input terminal of the DC-side driver corresponding to each second bridge arm circuit is connected to the fourth drive output terminal of the controller.

[0017] In one embodiment, the DC-AC converter circuit further includes:

[0018] Multiple AC-side windings, each AC-side winding corresponding to a DC-side winding;

[0019] An AC-side conversion circuit, in which multiple AC-side windings are connected in series to the AC-side conversion circuit;

[0020] Multiple AC-side drivers are used, and each switching transistor in the AC-side conversion circuit is connected to a different drive output terminal of the controller through each AC-side driver.

[0021] In one embodiment, the DC-AC conversion circuit further includes a resonant capacitor AC-side conversion circuit including a first bidirectional switching bridge arm circuit;

[0022] The first end of the resonant capacitor is connected to the midpoint of the first bidirectional switching bridge arm circuit, and the second end of the resonant capacitor is connected to the first end after the AC side windings are connected in series; the second end after the AC side windings are connected in series is connected to the first or second end of the first bidirectional switching bridge arm circuit.

[0023] or,

[0024] The first end of the resonant capacitor is connected to the midpoint of the first bidirectional switching bridge arm circuit, and the second end of the resonant capacitor is connected to the first end after the AC side windings are connected in series. The AC side conversion circuit also includes a second bidirectional switching bridge arm circuit, and the second end after the AC side windings are connected in series is connected to the midpoint of the second bidirectional switching bridge arm circuit.

[0025] or,

[0026] The first end of the resonant capacitor is connected to the midpoint of the first bidirectional switching bridge arm circuit, and the second end of the resonant capacitor is connected to the first end of the AC side windings connected in series. The AC side conversion circuit also includes a capacitor bridge arm circuit, and the second end of the AC side windings connected in series is connected to the midpoint of the capacitor bridge arm circuit.

[0027] or,

[0028] The first end of the resonant capacitor is connected to the position between the two switching transistors of the upper arm of the first bidirectional switching bridge arm circuit, and the second end of the resonant capacitor is connected to the first end after the AC side windings are connected in series; the second end after the AC side windings are connected in series is connected to the position between the two switching transistors of the lower arm of the first bidirectional switching bridge arm circuit.

[0029] In one embodiment, the DC-AC converter circuit further includes a drive power supply circuit;

[0030] The drive power supply circuit includes a buck converter circuit, multiple secondary windings and multiple rectifier circuits. The DC output terminal of the buck converter circuit is connected to the power supply terminal of each DC-side driver. The inductive element in the buck converter circuit serves as the primary winding corresponding to the multiple secondary windings.

[0031] The input terminal of each rectifier circuit is connected to the secondary winding, and the output terminal of each rectifier circuit is connected to the power supply terminal of each AC side driver.

[0032] In one embodiment, a high-frequency noise suppression element is provided between the input terminal of each rectifier circuit and each secondary winding.

[0033] In one embodiment, the high-frequency noise suppression element is a magnetic bead.

[0034] In one embodiment, the AC-side conversion circuit includes a first bidirectional switching bridge arm circuit;

[0035] The DC-AC converter circuit also includes a resonant circuit, which is connected to the first bidirectional switch bridge arm circuit.

[0036] Secondly, this application provides a power conversion device, including the DC-AC conversion circuit provided in the first aspect.

[0037] The aforementioned DC-AC conversion circuit and power conversion device include: multiple DC-side conversion circuits; multiple DC-side windings, with each DC-side conversion circuit connected to a specific DC-side winding; and a controller, where switching transistors located at the same topological position in each DC-side conversion circuit are connected to the same drive output terminal of the controller. In this way, the number of controller pins occupied by multiple DC-side conversion circuits is the same as the number of controller pins occupied by a single DC-side conversion circuit. This eliminates the need for a controller with a large number of I / O pins due to the multiple parallel conversion circuits on the DC side. Using the aforementioned DC-AC conversion circuit saves controller I / O resources, reduces controller I / O port requirements, and consequently reduces the controller chip area. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is a block diagram of a DC-AC converter circuit in one embodiment;

[0040] Figure 2 This is a schematic diagram of the circuit topology of a DC-AC converter circuit in one embodiment, where the DC-side converter circuit uses a full-bridge converter circuit.

[0041] Figure 3 This is a schematic diagram of the signal connection of the two DC-side drivers when the DC-AC conversion circuit includes two DC-side conversion circuits in one embodiment.

[0042] Figure 4 This is a schematic diagram of the signal connections of the four DC-side drivers when the DC-side conversion circuit includes two DC-side conversion circuits and the DC-side conversion circuit adopts a full-bridge conversion circuit in one embodiment.

[0043] Figure 5 This is a schematic diagram of the signal connection of the two AC side drivers when the AC side conversion circuit includes the first bidirectional switching bridge arm circuit in one embodiment.

[0044] Figure 6 This is a schematic diagram of the circuit topology of the resonant circuit and the AC-side conversion circuit in one embodiment;

[0045] Figure 7 This is a schematic diagram of the circuit topology of the resonant circuit and the AC-side conversion circuit in another embodiment;

[0046] Figure 8This is a schematic diagram of the circuit topology of the resonant circuit and the AC-side conversion circuit in another embodiment;

[0047] Figure 9 This is a schematic diagram of the circuit topology of the resonant circuit and the AC-side conversion circuit in another embodiment;

[0048] Figure 10 This is a schematic diagram of the circuit topology of the drive power supply circuit in one embodiment.

[0049] Figure label:

[0050] 100 DC-side converter circuit; 200 AC-side converter circuit; 300 Drive power supply circuit; 310 Step-down converter circuit; 320 Rectifier circuit; 330 High-frequency noise suppression component. Detailed Implementation

[0051] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0052] Unless otherwise defined, 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 is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0053] It is understood that the terms "first," "second," etc., used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0054] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0055] It is understood that the term "based on" as used in this application is used to describe one or more factors that influence the determination, but does not exclude other factors that may influence the determination. For example, the phrase "determine A based on B" means that the determination of A can be based entirely or at least partially on factor B. That is, B is a factor that influences the determination of A, but does not exclude the fact that the determination of A is also based on C.

[0056] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0057] In one exemplary embodiment, please refer to Figure 1 The DC-AC conversion circuit includes multiple DC-side conversion circuits 100 and multiple DC-side windings ( Figure 1 (N11 to N1n) and controller ( Figure 1 (Not shown in the image).

[0058] Each DC-side conversion circuit 100 is connected to a DC-side winding. In one possible implementation, the first terminals of the plurality of DC-side conversion circuits 100 are respectively connected to a plurality of DC sources, such as... Figure 1 As shown. In another possible implementation, the first terminals of multiple DC-side conversion circuits 100 are connected in parallel to the same DC source DC.

[0059] In each DC-side conversion circuit 100, the switching transistors located at the same topological position are connected to the same drive output terminal of the controller. Thus, in this embodiment, the number of controller pins occupied by multiple DC-side conversion circuits 100 is the same as the number of controller pins occupied when setting up a single DC-side conversion circuit 100. It is not necessary to use a controller with more I / O pins because multiple parallel conversion circuits are set up on the DC side. By using the DC-AC conversion circuit provided in this application embodiment, controller I / O resources can be saved, controller I / O port requirements can be reduced, and the chip area of ​​the controller can be reduced.

[0060] In this embodiment, the drive signals of the switching transistors located at the same topological position in each DC-DC converter circuit come from the same I / O port of the controller, which reduces the time delay between each parallel DC-side converter circuit 100 and improves the working phase consistency of each DC-DC converter circuit. In the embodiment where each AC-side winding is connected in series to the AC-side converter circuit 200, the gain generated after multiple AC-side windings are connected in series is the greatest.

[0061] In some embodiments, the DC-side conversion circuit 100 employs a full-bridge conversion circuit. For example, please refer to... Figure 2 This is a schematic diagram of the circuit topology of the DC-side converter circuit 100, which uses a full-bridge converter circuit. Figure 2Taking a DC-AC converter circuit comprising two DC-side converter circuits 100 as an example, the first bridge arm circuit of the first DC-side converter circuit 100 includes series-connected switches T11 and T12, and the second bridge arm circuit of the first DC-side converter circuit 100 includes series-connected switches T13 and T14. The first bridge arm circuit of the second DC-side converter circuit 100 includes series-connected switches T21 and T22, and the second bridge arm circuit of the second DC-side converter circuit 100 includes series-connected switches T23 and T24. The first DC-side converter circuit 100 is connected to the DC source DC via capacitor C1, and the second DC-side converter circuit 100 is connected to the DC source DC via capacitor C2. Switch T11 and switch T21 are located in the upper bridge arm of the first bridge arm circuit in the two DC-side conversion circuits 100, that is, switch T11 and switch T21 are located in the same topology position. In this embodiment, the driving terminals of switch T11 and switch T21 are connected to the same driving output terminal of the controller, for example, connected to pin 1 of the controller; similarly, switch T12 and switch T22 are located in the same topology position, and their driving terminals are both connected to pin 2 of the controller; switch T13 and switch T23 are located in the same topology position, and their driving terminals are both connected to pin 3 of the controller; switch T14 and switch T24 are located in the same topology position, and their driving terminals are both connected to pin 4 of the controller.

[0062] In some embodiments, the DC-side conversion circuit 100 employs a half-bridge conversion circuit, and... Figure 2 The circuit topology shown is similar, except that the two series-connected switching transistors in the second bridge arm circuit of the DC-side converter circuit 100 are replaced with two series-connected capacitors.

[0063] In one exemplary embodiment, the DC-AC conversion circuit includes multiple DC-side drivers, and the switching transistors located at the same topological position in each DC-side conversion circuit 100 are connected to the same drive output terminal of the controller through different DC-side drivers.

[0064] Each switching transistor is equipped with a corresponding driver. The DC-side driver refers to the driver corresponding to each switching transistor in the DC-side conversion circuit 100, and the same model or type of switching transistor driver can be used as the AC-side driver corresponding to each switching transistor in the AC-side conversion circuit 200 in the subsequent embodiment.

[0065] The controller outputs a drive control PWM (Pulse Width Modulation) signal to the driver, which is connected to the drive terminal of the switching transistor and is used to control the switching transistor to turn on and off based on the PWM signal and drive voltage.

[0066] In one possible implementation, the DC-side driver includes two drive input terminals and two drive output terminals. In this implementation, the first bridge arm circuit of each DC-side conversion line includes a first switch and a second switch. Each first bridge arm circuit corresponds to a DC-side driver. The first drive output terminal of the DC-side driver corresponding to each first bridge arm circuit is connected to each first switch, and the second drive output terminal of the DC-side driver corresponding to each first bridge arm circuit is connected to each second switch. The first drive input terminal of the DC-side driver corresponding to each first bridge arm circuit is connected to the first drive output terminal of the controller, and the second drive input terminal of the DC-side driver corresponding to each first bridge arm circuit is connected to the second drive output terminal of the controller.

[0067] In the DC-side conversion circuit 100, the two switches located on the same bridge arm are complementary and conduct. In this embodiment, the DC-side driver receives a pair of logic signals processed by the controller after dead time, and then generates two independent, electrically isolated drive signals to drive the upper bridge arm switch and the lower bridge arm switch, respectively.

[0068] For example, please refer to Figure 3 This is a schematic diagram showing the signal connections of two DC-side drivers (driver 1 and driver 2) when the DC-AC converter circuit includes two DC-side converter circuits 100; please refer to... Figure 2 and Figure 3 Driver 1 provides drive signals for switches T11 and T12 in the first bridge arm circuit of the first DC-side converter circuit 100, and driver 2 provides drive signals for switches T21 and T22 in the first bridge arm circuit of the second DC-side converter circuit 100. The first drive input terminal Pin11 of driver 1 and the first drive input terminal Pin21 of driver 2 are connected to the first drive output terminal PWMH1 of the controller, and the second drive input terminal Pin12 of driver 1 and the second drive input terminal Pin22 of driver 2 are connected to the second drive output terminal PWML1 of the controller. The first drive output terminal Pout11 of driver 1 is connected to the drive terminal of switch T11, the second drive output terminal Pout12 of driver 1 is connected to the drive terminal of switch T12, the first drive output terminal Pout21 of driver 2 is connected to the drive terminal of switch T21, and the second drive output terminal Pout22 of driver 2 is connected to the drive terminal of switch T22.

[0069] In one possible implementation, the second bridge arm circuit of each DC-side converter circuit 100 includes a third switch and a fourth switch, and each second bridge arm circuit corresponds to a DC-side driver; the first drive output terminal of the DC-side driver corresponding to each second bridge arm circuit is connected to each third switch, and the second drive output terminal of the DC-side driver corresponding to each second bridge arm circuit is connected to each fourth switch; the first drive input terminal of the DC-side driver corresponding to each second bridge arm circuit is connected to the third drive output terminal of the controller, and the second drive input terminal of the DC-side driver corresponding to each second bridge arm circuit is connected to the fourth drive output terminal of the controller. In this embodiment, as... Figure 2 As shown, each DC-side conversion circuit 100 adopts a full-bridge conversion circuit, and correspondingly, each DC-side conversion circuit 100 has two DC-side drivers.

[0070] Please refer to Figure 4 This is a schematic diagram showing the signal connections of four DC-side drivers (driver 1, driver 2, driver 3, and driver 4) when the DC-side conversion circuit 100 includes two DC-side conversion circuits 100 and the DC-side conversion circuit 100 adopts a full-bridge conversion circuit. Please refer to... Figure 2 and Figure 4 Driver 3 provides drive signals for switches T13 and T14 in the second bridge arm circuit of the first DC-side converter circuit 100, and driver 4 provides drive signals for switches T23 and T24 in the second bridge arm circuit of the second DC-side converter circuit 100. The first drive input terminal Pin31 of driver 3 and the first drive input terminal Pin41 of driver 4 are connected to the third drive output terminal PWMH2 of the controller, and the second drive input terminal Pin42 of driver 3 and the second drive input terminal Pin42 of driver 4 are connected to the fourth drive output terminal PWML2 of the controller. The first drive output terminal Pout31 of driver 3 is connected to the drive terminal of switch T13, the second drive output terminal Pout32 of driver 3 is connected to the drive terminal of switch T14, the first drive output terminal Pout41 of driver 4 is connected to the drive terminal of switch T23, and the second drive output terminal Pout42 of driver 4 is connected to the drive terminal of switch T24.

[0071] In one exemplary embodiment, please continue to refer to Figure 1 The DC-AC converter circuit provided in this application includes multiple AC side windings ( Figure 1 N21 to N2n), AC-side conversion circuit 200 and multiple AC-side drivers ( Figure 1(not shown in the figure), each AC side winding corresponds to each DC side winding, and multiple AC side windings are connected in series to the AC side conversion circuit 200. Each switching transistor in the AC side conversion circuit 200 is connected to a different drive output terminal of the controller through each AC side driver.

[0072] In one possible implementation, the AC-side conversion circuit 200 includes a first bidirectional switching bridge arm circuit, such as... Figure 2 As shown, the upper bridge arm circuit of the AC-side conversion circuit 200 includes a bidirectional switch composed of switching transistors T5 and T6, and the lower bridge arm circuit includes a bidirectional switch composed of switching transistors T7 and T8. Optionally, the AC-side conversion circuit 200 also includes a capacitor bridge arm, which includes two capacitors C3 and C4 connected in series. One end of the AC-side windings connected in series is connected to the midpoint of the first bidirectional switch bridge arm circuit, and the other end is connected to the midpoint of the capacitor bridge arm. Capacitor C5 serves as a filter capacitor between the AC-side conversion circuit 200 and the AC source.

[0073] Optionally, the AC-side driver includes two drive input terminals and two drive output terminals, wherein switching transistors T5 and T6 are driven by the same AC-side driver, and switching transistors T7 and T8 are driven by the same AC-side driver. For an example, please refer to... Figure 5 This is a schematic diagram showing the signal connections of the two AC-side drivers (driver 5 and driver 6, respectively) when the AC-side conversion circuit 200 includes the first bidirectional switching bridge arm circuit. Please refer to... Figure 2 and Figure 5 Driver 5 provides drive signals for switching transistors T5 and T6, and driver 6 provides drive signals for switching transistors T7 and T8. The first drive input terminal Pin51 of driver 5 is connected to the fifth drive output terminal PWM5 of the controller, the second drive input terminal Pin52 of driver 5 is connected to the sixth drive output terminal PWM6 of the controller, the first drive input terminal Pin61 of driver 6 is connected to the seventh drive output terminal PWM7 of the controller, and the second drive input terminal Pin62 of driver 6 is connected to the eighth drive output terminal PWM8 of the controller. The first drive output terminal Pout51 of driver 5 is connected to the drive terminal of switching transistor T5, the second drive output terminal Pout52 of driver 5 is connected to the drive terminal of switching transistor T6, the first drive output terminal Pout61 of driver 6 is connected to the drive terminal of switching transistor T7, and the second drive output terminal Pout62 of driver 6 is connected to the drive terminal of switching transistor T8.

[0074] In one possible implementation, the DC-AC converter circuit further includes a resonant circuit connected to the first bidirectional switching bridge arm circuit of the AC-side converter circuit 200. The resonant circuit includes a resonant capacitor.

[0075] Please refer to Figures 6 to 8 The AC-side conversion circuit includes a first bidirectional switching bridge arm circuit. The first end of the resonant capacitor is connected to the midpoint of the first bidirectional switching bridge arm circuit, and the second end of the resonant capacitor is connected to the first end of each AC winding connected in series.

[0076] Optionally, the AC-side conversion circuit also includes a capacitor bridge arm circuit, with the second end of the series-connected AC-side windings connected to the midpoint of the capacitor bridge arm circuit. Please refer to [reference needed]. Figure 6 The resonant circuit includes a resonant capacitor C6, which is connected between the midpoint of the first bidirectional switching bridge arm circuit and the AC side winding. The second end of the AC side windings connected in series is connected between capacitors C3 and C4. In this alternative configuration, the leakage inductance of the transformer can be used as the resonant inductance, together with the resonant capacitor C6, to provide the resonant frequency for the circuit.

[0077] In another alternative approach, the resonant capacitor in the resonant circuit can also be positioned between the midpoint of the capacitor bridge arm circuit and the secondary winding.

[0078] Optionally, the second end of the AC-side windings connected in series is connected to either the first or second end of the first bidirectional switching bridge arm circuit. Please refer to [reference needed]. Figure 7 The resonant circuit includes an inductor L1 and a resonant capacitor C7 connected in series. The first end of the AC windings connected in series is connected to the midpoint of the first bidirectional switching bridge arm circuit via inductor L1 and resonant capacitor C7, and the second end is connected to one of the two ends of the first bidirectional switching bridge arm circuit. In this optional implementation, for example, inductor L1 can be an independently configured resonant inductor; alternatively, a transformer with leakage inductance can be used, and inductor L1 can be implemented using the transformer's leakage inductance.

[0079] Optionally, the AC-side conversion circuit also includes a second bidirectional switching arm circuit, with the second end of the AC-side windings connected in series to a key location in the second bidirectional switching arm circuit. Please refer to [reference needed]. Figure 8 The upper arm of the second bidirectional switching bridge arm circuit includes switching transistors T9 and T10 with opposite conduction directions, and the lower arm includes switching transistors T11 and T12 with opposite conduction directions. The resonant circuit includes a resonant capacitor C8; the first end of the AC windings connected in series is connected to the midpoint of the first bidirectional switching bridge arm circuit via capacitor C8, and the second end is connected to the midpoint of the second bidirectional switching bridge arm circuit. In this optional implementation, for example, a transformer with leakage inductance is used, and the resonant circuit is constructed based on the resonant capacitor and the leakage inductance of the transformer to provide a resonant frequency for the DC-AC conversion circuit; another example may refer to... Figure 7 The resonant circuit shown uses an independent inductor as the resonant inductor.

[0080] In an exemplary embodiment, the AC-side conversion circuit includes a first bidirectional switching bridge arm circuit. A first end of a resonant capacitor is connected to the position between the two switching transistors of the upper bridge arm of the first bidirectional switching bridge arm circuit. A second end of the resonant capacitor is connected to the first end of the series-connected AC-side windings. The second end of the series-connected AC-side windings is connected to the position between the two switching transistors of the lower bridge arm of the first bidirectional switching bridge arm circuit. Please refer to... Figure 9 The resonant circuit includes a resonant capacitor C9 and an inductor L2, wherein the inductor L2 and the resonant capacitor C9 are connected in series. After the AC side windings are connected in series, the first terminal is connected through the inductor L2 and the resonant capacitor C9 to the position between the switching transistors T5 and T6 of the first bidirectional switching bridge arm circuit, and the second terminal is connected to the position between the switching transistors T7 and T8. In this optional configuration, the capacitor bridge arm circuit may not be included in the AC side conversion circuit 200.

[0081] It should be noted that the midpoint position in the embodiments of this application does not refer to the midpoint of physical distance, but rather to the midpoint position in electrical relationship, such as... Figure 8 In this context, the midpoint of the first bidirectional switching bridge arm circuit refers to any point on the circuit between the upper and lower bridge arm circuits where a power supply connection is possible.

[0082] In one exemplary embodiment, the DC-AC converter circuit further includes a drive power supply circuit 300, please refer to... Figure 10 The drive power supply circuit 300 includes a step-down converter circuit 310 and multiple secondary windings ( Figure 10 The circuit includes secondary windings N41 and N42 and multiple rectifier circuits 320. The DC output terminal (Vccp-AGND) of the buck converter circuit 310 is connected to the power supply terminal of each DC-side driver. The inductive element N3 in the buck converter circuit 310 serves as the primary winding corresponding to the multiple secondary windings. The input terminal of each rectifier circuit 320 is connected to each secondary winding, and the output terminal of each rectifier circuit 320 is connected to the power supply terminal of each AC-side driver. Figure 10 The example uses two secondary windings and two rectifier circuits (320).

[0083] In one possible implementation, the input of the buck converter circuit 310 can be connected to the power grid via an AC-DC converter circuit, meaning the grid voltage is converted from AC to DC to provide power to the drive power supply circuit 300. In another possible implementation, the input of the buck converter circuit 310 can be connected to the battery pack of an energy storage device, meaning the drive power supply circuit 300 draws power from the battery.

[0084] In one possible implementation, the DC-AC conversion circuit is applied in the energy storage converter. The input terminal of the drive power supply circuit 300 can be connected to the power grid and the battery module of the energy storage device through the AC-DC conversion circuit. This allows the drive power supply circuit 300 to draw power from both the power grid and the battery, ensuring that the DC-AC conversion circuit can work normally in both high-voltage and low-voltage grid scenarios and off-grid scenarios.

[0085] like Figure 10 As shown, the buck converter circuit 310 includes capacitor C10, capacitor C11, switching transistors T31 and T32, and inductive element N3. The two ends of capacitor C10 are connected to the input terminal of the buck converter circuit 310. The drain of switching transistor T31 is connected to the first end of capacitor C10. The source of switching transistor T31 is connected to the first end of inductive element N3 and the drain of switching transistor T32. The second end of inductive element N3 is connected to the first end of capacitor C11. The source of switching transistor T32 is connected to the second end of capacitor C11 and the first end of capacitor C10. Inductive element N3 is anti-coupled to each secondary winding. The two ends of capacitor C11 serve as the DC output terminal (Vccp-AGND) of the buck converter circuit 310. When switching transistor T31 is turned off, the energy stored in inductive element N3 is released to the secondary winding and the DC output terminal.

[0086] In this circuit, the DC output terminal Vccp of the buck converter circuit 310 is connected to the power supply terminal of each DC-side driver, such as... Figure 3 and Figure 4 As shown, the power input terminals of drivers 1 to 4 are all connected to the DC output terminal Vccp of the buck converter circuit 310.

[0087] For example, such as Figure 10 As shown, the first rectifier circuit 320 includes a diode D1 and a capacitor C12. The anode of diode D1 is connected to the first terminal of the secondary winding N41, the cathode of diode D1 is connected to the first terminal of capacitor C12, and the second terminal of capacitor C12 is connected to the second terminal of the secondary winding N42. The first terminal of capacitor C12 serves as the positive output terminal Vcc1 of the first rectifier circuit 320, and the second terminal of capacitor C12 serves as the ground output terminal Vee1 of the first rectifier circuit 320. Please refer to... Figure 5 and Figure 2 The high-level input terminal of driver 5 is connected to the positive output terminal Vcc1, the low-level input terminal of driver 5 is connected to the ground output terminal Vee1, and the reference voltage output terminal Pout53 of driver 5 is connected to the reference voltage point A between switching transistors T5 and T6. Inside driver 5, Vin52 is directly connected to the reference voltage output terminal Pout53, that is, the reference voltage point A is connected to the ground output terminal Vee1 of the first rectifier circuit 320 through driver 5.

[0088] For example, such as Figure 10 As shown, the second rectifier circuit 320 includes a diode D2 and a capacitor C13. The anode of diode D2 is connected to the first terminal of the secondary winding N42, and the cathode of diode D2 is connected to the first terminal of capacitor C13. The second terminal of capacitor C13 is connected to the second terminal of the secondary winding N42. The first terminal of capacitor C13 serves as the positive output terminal Vcc2 of the second rectifier circuit 320, and the second terminal of capacitor C13 serves as the ground output terminal Vee2 of the second rectifier circuit 320. Figure 5 and Figure 2 The high-level input terminal of driver 6 is connected to the positive output terminal Vcc2, the low-level input terminal of driver 6 is connected to the ground output terminal Vee2, and the reference voltage output terminal Pout63 of driver 6 is connected to the reference voltage point B between switching transistors T7 and T8. Inside driver 6, Vin62 is directly connected to the reference voltage output terminal Pout63, that is, the reference voltage point B is connected to the ground output terminal Vee2 of the second rectifier circuit 320 through driver 6.

[0089] In other examples, the rectifier circuit 320 may also employ other circuit topologies to rectify the AC output from the AC side winding into a stable DC output AC side driver.

[0090] In one possible implementation, please continue to refer to Figure 10 High-frequency noise suppression components 330 are provided between the input terminals of each rectifier circuit 320 and each secondary winding to suppress high-frequency noise generated by the switching transistors in the AC-side conversion circuit during high-frequency switching, which is coupled to the buck converter circuit 310 through the parasitic capacitance between the primary and secondary windings. This reduces the impact of high-frequency noise on the switching action of the switching transistors T31 and T32 in the buck converter circuit 310, and also reduces the impact of high-frequency noise on the ground terminal AGND of the drive power supply circuit 300. As a result, the interference of AC-side high-frequency noise on other circuits or IC (Integrated Circuit) devices that draw power from the ground terminal AGND of the same power supply network can be reduced, thereby improving the reliability and stability of the drive power supply circuit 300 and the entire system.

[0091] For example, the high-frequency noise suppression element 330 is a ferrite bead. The ferrite bead has a large impedance in the high-frequency range, which can dissipate the energy generated when the high-frequency noise current flows through it by converting it into heat energy through magnetic loss; the ferrite bead has a very low impedance in the low-frequency range, which hardly affects the transmission of DC or low-frequency signals, and can effectively filter out high-frequency noise without affecting the operation of the rectifier circuit 320.

[0092] In this embodiment, the switching transistor in the DC-side conversion circuit can be a 40V, 80V, or 100V rated transistor, such as a Si MOS (Silicon Metal-Oxide-Semiconductor), GaN (Gallium Nitride), or SiCMOS (Silicon Carbide Metal-Oxide-Semiconductor). The AC-side switching transistor in the AC-side conversion circuit can be a 600V or 650V rated transistor, such as a Si MOS, GaN, SiCMOS, or an IGBT (Insulated Gate Bipolar Transistor).

[0093] In one exemplary embodiment, a power conversion device is provided, including the DC-AC conversion circuit provided in the above embodiment.

[0094] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0095] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A DC-AC converter circuit, characterized in that, The DC-AC conversion circuit includes: Multiple DC-side conversion circuits; Multiple DC-side windings, and each DC-side conversion circuit is connected to each DC-side winding respectively; The controller, in which the switching transistors in each of the DC-side conversion circuits are located in the same topological position are connected to the same drive output terminal of the controller.

2. The DC-AC converter circuit according to claim 1, characterized in that, The DC-AC conversion circuit includes: Multiple DC-side drivers are provided, and the switching transistors located at the same topological position in each DC-side conversion circuit are connected to the same drive output terminal of the controller through different DC-side drivers.

3. The DC-AC converter circuit according to claim 2, characterized in that, The DC-side driver includes two drive input terminals and two drive output terminals; Each of the DC-side converter circuits includes a first switch and a second switch, and each of the first bridge arm circuits corresponds to a DC-side driver. The first drive output terminal of the DC-side driver corresponding to each first bridge arm circuit is connected to each first switch transistor, and the second drive output terminal of the DC-side driver corresponding to each first bridge arm circuit is connected to each second switch transistor. The first drive input terminal of the DC-side driver corresponding to each of the first bridge arm circuits is connected to the first drive output terminal of the controller, and the second drive input terminal of the DC-side driver corresponding to each of the first bridge arm circuits is connected to the second drive output terminal of the controller.

4. The DC-AC converter circuit according to claim 3, characterized in that, Each of the DC-side converter circuits includes a third switch and a fourth switch, and each of the second bridge arm circuits corresponds to one of the DC-side drivers. The first drive output terminal of the DC-side driver corresponding to each of the second bridge arm circuits is connected to each of the third switching transistors, and the second drive output terminal of the DC-side driver corresponding to each of the second bridge arm circuits is connected to each of the fourth switching transistors. The first drive input terminal of the DC-side driver corresponding to each of the second bridge arm circuits is connected to the third drive output terminal of the controller, and the second drive input terminal of the DC-side driver corresponding to each of the second bridge arm circuits is connected to the fourth drive output terminal of the controller.

5. The DC-AC converter circuit according to claim 2, characterized in that, The DC-AC conversion circuit also includes: Multiple AC-side windings, each AC-side winding corresponding to a DC-side winding; An AC-side conversion circuit, wherein the plurality of AC-side windings are connected in series to the AC-side conversion circuit; Multiple AC-side drivers are provided, and each switching transistor in the AC-side conversion circuit is connected to a different drive output terminal of the controller through each AC-side driver.

6. The DC-AC converter circuit according to claim 5, characterized in that, The DC-AC conversion circuit also includes a resonant capacitor, and the AC-side conversion circuit includes a first bidirectional switching bridge arm circuit. The first end of the resonant capacitor is connected to the midpoint of the first bidirectional switch bridge arm circuit, and the second end of the resonant capacitor is connected to the first end of the AC side windings connected in series; the second end of the AC side windings connected in series is connected to either the first or second end of the first bidirectional switch bridge arm circuit. or, The first end of the resonant capacitor is connected to the midpoint of the first bidirectional switching bridge arm circuit, and the second end of the resonant capacitor is connected to the first end of the AC side windings connected in series. The AC side conversion circuit also includes a second bidirectional switching bridge arm circuit, and the second end of the AC side windings connected in series is connected to the midpoint of the second bidirectional switching bridge arm circuit. or, The first end of the resonant capacitor is connected to the midpoint of the first bidirectional switching bridge arm circuit, and the second end of the resonant capacitor is connected to the first end of the AC side windings connected in series. The AC side conversion circuit also includes a capacitor bridge arm circuit, and the second end of the AC side windings connected in series is connected to the midpoint of the capacitor bridge arm circuit. or, The first end of the resonant capacitor is connected to the position between the two switching transistors of the upper arm of the first bidirectional switching bridge arm circuit, and the second end of the resonant capacitor is connected to the first end after the AC side windings are connected in series; the second end after the AC side windings are connected in series is connected to the position between the two switching transistors of the lower arm of the first bidirectional switching bridge arm circuit.

7. The DC-AC converter circuit according to claim 5, characterized in that, The DC-AC conversion circuit also includes a drive power supply circuit; The drive power supply circuit includes a buck converter circuit, multiple secondary windings and multiple rectifier circuits. The DC output terminal of the buck converter circuit is connected to the power supply terminal of each DC-side driver. The inductive element in the buck converter circuit serves as the primary winding corresponding to the multiple secondary windings. The input terminal of each rectifier circuit is connected to the secondary winding of each rectifier circuit, and the output terminal of each rectifier circuit is connected to the power supply terminal of each AC side driver.

8. The DC-AC converter circuit according to claim 7, characterized in that, A high-frequency noise suppression element is provided between the input terminal of each rectifier circuit and each secondary winding.

9. The DC-AC converter circuit according to claim 8, characterized in that, The high-frequency noise suppression element is a magnetic bead.

10. The DC-AC converter circuit according to claim 5, characterized in that, The AC-side conversion circuit includes a first bidirectional switching bridge arm circuit; The DC-AC converter circuit also includes a resonant circuit, which is connected to the first bidirectional switch bridge arm circuit.

11. A power conversion device, characterized in that, The power conversion device includes a DC-AC conversion circuit as described in any one of claims 1-10.

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