A driving power supply, power converter and control method
By employing a transformer and resonant circuit design in the drive power supply, the number of diodes and capacitors is reduced, simplifying the hardware circuit, lowering costs, solving the problem of increased component count in existing technologies, and achieving more efficient power transmission.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SUNGROWPOWER SUPPLY (JIANGSU) CO LTD
- Filing Date
- 2026-04-23
- Publication Date
- 2026-07-21
AI Technical Summary
Existing driver power supplies use isolated DC/DC power supplies, resulting in complex hardware circuits and high costs, especially with an increase in the number of components when there are multiple outputs.
The primary winding of the transformer is connected to the output terminal of the primary circuit through a resonant circuit. The secondary circuit uses a single diode rectifier circuit to reduce the number of diodes and capacitors, and the number of capacitors connected to the primary circuit is reduced through the resonant circuit.
It simplifies the hardware circuit structure, reduces the number of components and cost, and improves the stability and efficiency of the circuit.
Smart Images
Figure CN122437354A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of power transistor power supply technology, specifically to a drive power supply, a power converter, and a control method. Background Technology
[0002] A power converter includes multiple power transistors. As active devices, these transistors require a driving power supply during operation. Because the power converter includes multiple power transistors, the driving power supply has multiple outputs, each supplying power to its corresponding power transistor.
[0003] The driving power supply in the related technology adopts an isolated DC / DC power supply. The primary circuit includes multiple ceramic capacitors connected in parallel to obtain a large capacitance value to prevent oscillation. The secondary circuit adopts a voltage doubler rectifier circuit, which includes not only a large number of ceramic capacitors, but also a large number of rectifier diodes.
[0004] Therefore, the more output channels the secondary circuit of the driving power supply has, the more components are involved in the circuit, resulting in complex hardware circuitry and higher costs. Summary of the Invention
[0005] In view of this, this application provides a drive power supply, a power converter, and a control method, which can reduce the number of components, simplify the hardware circuit, and reduce costs.
[0006] This application provides a driving power supply, including: a primary circuit, a transformer, and multiple secondary circuits;
[0007] The primary winding of the transformer is connected to the output terminal of the primary circuit through a resonant circuit, and the input terminal of the primary circuit is used to connect to a DC source.
[0008] The secondary circuit is connected to the corresponding secondary winding;
[0009] The secondary circuit includes diodes, with the anodes of some diodes in the secondary circuit connected to the same-name terminals of the secondary winding, and the anodes of the diodes in the remaining secondary circuits connected to the opposite-name terminals of the secondary winding.
[0010] In one possible implementation, the resonant circuit includes a resonant capacitor and a resonant inductor, wherein the resonant inductor is an external inductor or the leakage inductance of the transformer;
[0011] The ratio of the resonant frequency of the resonant circuit to the switching frequency of the primary circuit is less than a preset value.
[0012] One possible implementation is that the primary-side circuit is a half-bridge circuit or a full-bridge circuit;
[0013] The first output terminal of the primary circuit is connected to the first terminal of the primary winding through the resonant capacitor and the resonant inductor connected in series, and the second terminal of the primary winding is connected to the second output terminal of the primary circuit.
[0014] In one possible implementation, the secondary circuit further includes an output capacitor;
[0015] When the anode of the diode is connected to the same-name terminal of the secondary winding, the cathode of the diode is connected to the first terminal of the output capacitor, and the second terminal of the output capacitor is connected to the opposite-name terminal of the corresponding secondary winding.
[0016] In one possible implementation, the secondary circuit further includes an output capacitor;
[0017] When the anode of the diode is connected to the opposite terminal of the secondary winding, the cathode of the diode is connected to the first terminal of the output capacitor, and the second terminal of the output capacitor is connected to the same terminal of the corresponding secondary winding.
[0018] One possible implementation is that the absolute values of the output voltages of the multiple secondary circuits are the same.
[0019] One possible implementation is that the output voltage of the secondary circuit is less than the voltage of the DC source.
[0020] This application also provides a power converter, including: the driving power supply described above, and further including a plurality of power transistors; the output terminals of the plurality of secondary circuits of the driving power supply are respectively used to supply power to the corresponding power transistors.
[0021] This application also provides a method for controlling a drive power supply, including:
[0022] The first set of switches in the primary circuit of the drive power supply is turned on, and the second set of switches is turned off, so that the current in the resonant circuit flows from the primary circuit to the primary winding of the transformer; the primary winding of the transformer is connected to the output terminal of the primary circuit through the resonant circuit; the transformer includes multiple secondary windings, and the secondary windings are connected to corresponding secondary circuits; the secondary circuits include diodes, and the anodes of the diodes in some secondary circuits are connected to the same-name terminals of the corresponding secondary windings, while the anodes of the diodes in the remaining secondary circuits are connected to the opposite-name terminals of the corresponding secondary windings;
[0023] The first set of switches in the primary circuit of the drive power supply is turned off, and the second set of switches is turned on, so that the current in the resonant circuit flows from the primary winding of the transformer to the primary circuit.
[0024] One possible implementation is that the primary-side circuit is a half-bridge circuit or a full-bridge circuit;
[0025] The first output terminal of the primary circuit is connected to the first terminal of the primary winding through the resonant capacitor and the resonant inductor connected in series, and the second terminal of the primary winding is connected to the second output terminal of the primary circuit.
[0026] The embodiments of this application have the following beneficial effects:
[0027] The driving power supply provided in this application includes a primary circuit, a transformer, and multiple secondary circuits. The primary winding of the transformer is connected to the output terminal of the primary circuit via a resonant circuit. The secondary circuits are connected to their corresponding secondary windings. Each secondary circuit includes diodes; the anodes of some diodes in the secondary circuits are connected to the same-name terminal of the corresponding secondary winding, while the anodes of the diodes in the remaining secondary circuits are connected to the opposite-name terminal of the corresponding secondary winding. Notably, the secondary circuits do not employ a voltage doubler rectifier circuit but instead use a rectifier circuit comprising a single diode. The voltage doubler rectifier circuit includes two diodes and one capacitor. Therefore, the secondary circuits in this application reduce the number of diodes and capacitors. Furthermore, the primary circuit is connected to a resonant circuit, which further reduces the number of capacitors connected to the primary circuit. Overall, this reduces the number of components in the driving power supply and lowers the cost of the hardware circuitry. Attached Figure Description
[0028] Figure 1 A schematic diagram of a first type of driving power supply provided in an embodiment of this application;
[0029] Figure 2 A schematic diagram of a second type of driving power supply provided in an embodiment of this application;
[0030] Figure 3 A schematic diagram of a third type of driving power supply provided in an embodiment of this application;
[0031] Figure 4 A schematic diagram of the steady-state circuit waveform of the first type of driving power supply provided in the embodiments of this application;
[0032] Figure 5 A schematic diagram of the first type of steady-state switching mode of the driving power supply provided in the embodiments of this application;
[0033] Figure 6 A schematic diagram of a second type of steady-state switching mode of the driving power supply provided in an embodiment of this application;
[0034] Figure 7 A schematic diagram of a third steady-state switching mode of the driving power supply provided in the embodiments of this application;
[0035] Figure 8 A schematic diagram of the fourth steady-state switching mode of the driving power supply provided in the embodiments of this application;
[0036] Figure 9A schematic diagram of the steady-state circuit waveform of the second type of driving power supply provided in the embodiments of this application;
[0037] Figure 10 A schematic diagram of the fifth steady-state switching mode of the driving power supply provided in the embodiments of this application;
[0038] Figure 11 A schematic diagram of the sixth steady-state switching mode of the driving power supply provided in the embodiments of this application;
[0039] Figure 12 A schematic diagram of a fourth type of driving power supply provided in an embodiment of this application;
[0040] Figure 13 This is a schematic diagram of a first type of power converter provided in an embodiment of this application;
[0041] Figure 14 A flowchart of a first driving power supply control method provided in an embodiment of this application. Detailed Implementation
[0042] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.
[0043] The embodiments of this application do not specifically limit the application scenario of the drive power supply. For example, it can be used to provide drive power for the power transistors in a power converter.
[0044] This application does not specifically limit the number of output channels of the secondary circuit of the driving power supply, but it includes at least two secondary circuits. This application will describe the case where the number of output channels of the secondary circuit of the driving power supply is three.
[0045] See Figure 1 The figure is a schematic diagram of the first type of driving power supply provided in the embodiments of this application.
[0046] The driving power supply provided in this embodiment includes: a primary circuit 100, a transformer T, and multiple secondary circuits. The number of output channels of the secondary circuits can be N, where N is an integer greater than or equal to 2. This embodiment uses three secondary circuits as an example: a first secondary circuit 301, a second secondary circuit 302, and a third secondary circuit 303. The primary winding L of the transformer T is connected to the output terminal of the primary circuit 100 through a resonant circuit 200. The input terminal of the primary circuit 100 is used to connect to a DC source Vin, the voltage of which can be tens of volts. The resonant current of the resonant circuit 200 is represented by i. Lr express.
[0047] For example, the first secondary circuit 301 is connected to the first secondary winding L11, the second secondary circuit 302 is connected to the second secondary winding L12, and the third secondary circuit 303 is connected to the third secondary winding L13; the output voltages of the first secondary circuit 301, the second secondary circuit 302, and the third secondary circuit 303 are the first output voltage Vo1, the second output voltage Vo2, and the third output voltage Vo3, respectively; the first secondary circuit 301, the second secondary circuit 302, and the third secondary circuit 303 each include a first diode D1, a second diode D2, and a third diode D3.
[0048] In some secondary circuits, the anodes of the diodes are connected to the same-name terminals of the secondary windings, while in other secondary circuits, the anodes of the diodes are connected to the opposite-name terminals of the secondary windings. The number of secondary circuits in which the anodes of the diodes are connected to the opposite-name terminals of the secondary windings is K, where K is an integer less than N and greater than or equal to 1.
[0049] In this embodiment, N is 3 and K is 1, which is used as an example. It should be understood that when N is 3, K can also be 2. Figure 1 In the embodiment shown in this application, the anode of the first diode D1 is connected to the same-name terminal of the first secondary winding L11, the anode of the second diode D2 is connected to the same-name terminal of the second secondary winding L12, and the anode of the third diode D3 is connected to the opposite-name terminal of the third secondary winding L13.
[0050] The primary circuit 100 converts the DC input Vin into AC output, and the resonant circuit 200 generates a resonant current i. Lr The transformer T transfers the energy of the primary winding L to the first secondary winding L11, the second secondary winding L12, and the third secondary winding L13 of the transformer T. The currents on the first secondary winding L11, the second secondary winding L12, and the third secondary winding L13 are rectified by the first diode D1, the second diode D2, and the third diode D3, respectively, and then output. The first output voltage Vo1, the second output voltage Vo2, and the third output voltage Vo3 supply power to their respective loads.
[0051] Since each of the N-way secondary circuits uses a single diode for rectification, the number of components in the secondary circuit can be reduced. Moreover, in order to suppress the magnetic saturation of the transformer and demagnetize it, the anode of at least one diode in the N-way secondary circuit is connected to the opposite terminal of the corresponding secondary winding. In this way, the N-way secondary circuits will not transfer energy simultaneously. The secondary windings corresponding to the same terminal and the secondary windings corresponding to the opposite terminal transfer energy in the positive and negative half-cycles of the AC current, respectively, so as to achieve demagnetization of the transformer and reduce the risk of transformer magnetic saturation.
[0052] The driving power supply provided in this application includes a primary circuit, a transformer, and multiple secondary circuits. The primary winding of the transformer is connected to the output terminal of the primary circuit via a resonant circuit. The secondary circuits are connected to their corresponding secondary windings. Each secondary circuit includes diodes; the anodes of some diodes in the secondary circuits are connected to the same-name terminal of the corresponding secondary winding, while the anodes of the diodes in the remaining secondary circuits are connected to the opposite-name terminal of the corresponding secondary winding. Notably, the secondary circuits do not employ a voltage doubler rectifier circuit but instead use a rectifier circuit comprising a single diode. The voltage doubler rectifier circuit includes two diodes and one capacitor. Therefore, the secondary circuits in this application reduce the number of diodes and capacitors. Furthermore, the primary circuit is connected to a resonant circuit, which further reduces the number of capacitors connected to the primary circuit. Overall, this reduces the number of components in the driving power supply and lowers the cost of the hardware circuitry.
[0053] In order to filter and regulate the output voltage at the secondary output terminal, the driving power supply provided in this application embodiment includes an output capacitor, which will be described in detail below with reference to the accompanying drawings.
[0054] See Figure 2 The figure is a schematic diagram of the second type of driving power supply provided in the embodiments of this application.
[0055] The driving power supply provided in this application embodiment includes: multiple output capacitors, for example, the number of output capacitors can be N, where N is an integer greater than or equal to 2, and the N output capacitors are connected one-to-one with N secondary circuits. In this application embodiment, a three-way secondary circuit is used as an example, and the three output capacitors are the first output capacitor Co1, the second output capacitor Co2, and the third output capacitor Co3.
[0056] The anode of the first diode D1 is connected to the same-name terminal of the first secondary winding L11, the cathode of the first diode D1 is connected to the first terminal of the first output capacitor Co1, and the second terminal of the first output capacitor Co1 is connected to the opposite-name terminal of the first secondary winding L11.
[0057] The anode of the second diode D2 is connected to the same-name terminal of the second secondary winding L12, the cathode of the second diode D2 is connected to the first terminal of the second output capacitor Co2, and the second terminal of the second output capacitor Co2 is connected to the opposite-name terminal of the second secondary winding L12.
[0058] The anode of the third diode D3 is connected to the opposite terminal of the third secondary winding L13, the cathode of the third diode D3 is connected to the first terminal of the third output capacitor Co3, and the second terminal of the third output capacitor Co3 is connected to the same terminal of the third secondary winding L13.
[0059] The driving power supply provided in this application embodiment includes an output capacitor to filter and regulate the output voltage of the secondary side, making the output voltage of the secondary side more stable and ensuring that it provides stable and high-quality power support for subsequent loads.
[0060] In related technologies, the primary-side circuit includes multiple ceramic capacitors connected in parallel to obtain a large capacitance value for the DC blocking capacitor to prevent oscillation. In this embodiment, to reduce the capacitance value of the DC blocking capacitor connected in the primary-side circuit, a resonant circuit is provided on the primary side of the transformer. The resonant circuit includes a resonant capacitor and a resonant inductor connected in series. The following continues in conjunction with... Figure 2 A detailed introduction will be provided.
[0061] The driving power supply provided in this embodiment includes: a resonant capacitor Cr and a resonant inductor L. k Resonant inductor L k The leakage inductance is for the external inductor or transformer T; the ratio of the resonant frequency fr of the resonant circuit 200 to the switching frequency fs of the primary circuit 100 is less than a preset value, ensuring that the resonant frequency fr is relatively close to the switching frequency fs. The resonant frequency fr can be slightly less than the switching frequency fs, or it can be slightly greater than the switching frequency fs. However, the capacitance of the DC blocking capacitor in related technologies is very large, resulting in an excessively long resonant period, much longer than the switching period. This is considered as the primary side of the transformer not resonating, and the current flowing through the primary winding of the transformer is a triangular wave.
[0062] When the driving power supply provided in this embodiment operates in a steady state, the resonant capacitor C r With resonant inductor L k The circuit resonates, and the resonant period is approximately equal to the switching period. Therefore, current flows through the resonant capacitor C. r The current is approximately sinusoidal.
[0063] The expression for the resonant frequency fr is:
[0064] .
[0065] The resonant frequency can be obtained from the switching frequency of the primary circuit, thereby determining the parameters of the resonant capacitor and resonant inductor.
[0066] The primary side of the driving power supply provided in this application embodiment also includes a resonant capacitor and a resonant inductor, and the switching frequency is near the resonant frequency, thereby reducing the capacitance value of the capacitor connected to the primary winding, eliminating the need to use multiple ceramic capacitors in parallel, and thus reducing the number of capacitors on the primary side.
[0067] The embodiments of this application do not specifically limit the type of the primary-side circuit, which can be a half-bridge circuit or a full-bridge circuit; the embodiments of this application do not specifically limit the specific type of the switching transistor in the primary-side circuit, such as a metal-oxide-semiconductor field-effect transistor (MOSFET) or an insulated-gate bipolar transistor (IGBT), etc.
[0068] The following section, with reference to the accompanying diagram, describes the implementation method when the primary circuit is a half-bridge circuit and the switching transistor is a MOSFET.
[0069] See Figure 3 This figure is a schematic diagram of the third type of driving power supply provided in the embodiments of this application.
[0070] The primary-side circuit 100 of the driving power supply provided in this application embodiment is a half-bridge circuit, which includes a first switch S1 and a second switch S2 connected in series. The first switch S1 and the second switch S2 are connected in series across the DC source Vin. The first output terminal of the primary-side circuit 100 is connected through a resonant capacitor C in series. r and resonant inductance L k The first end of the primary winding L is connected, and the second end of the primary winding L is connected to the second output terminal of the primary circuit 100; for example, in one possible implementation, the first switch S1 and the second switch S2 are complementaryly turned on during the switching cycle, the duty cycle of the on time is 50%, and the dead time is ignored.
[0071] The secondary circuit can have N output paths, where N is an integer greater than or equal to 2. The absolute values of the output voltages of the N output circuits are the same, that is, the turns ratio of the transformer T is n:1:1:1. When the driving power supply provided in this application embodiment is a step-down circuit, n is greater than 1. This application embodiment takes N as an example for introduction. Since the turns ratio of each secondary winding is the same, only the same-name terminals are different. Therefore, the absolute values of the first output voltage Vo1, the second output voltage Vo2, and the third output voltage Vo3 are equal.
[0072] Figure 3 The rest of the middle part and Figure 2 Same, see Figure 2 The description will not be repeated here.
[0073] In this application embodiment, the switching frequency fs can be less than the resonant frequency fr, or the switching frequency fs can be greater than the resonant frequency fr. The working principle when the switching frequency fs is less than the resonant frequency fr will be described below with reference to the accompanying drawings.
[0074] See Figure 4The figure is a schematic diagram of the steady-state current waveform of the first type of driving power supply provided in the embodiment of this application.
[0075] like Figure 4 As shown, the output voltage of the primary circuit 100 is represented by u. AB It means, u AB The output voltage of the transformer secondary circuit is also a square wave, the resonant current is a sine wave, and the excitation current is a triangular wave.
[0076] like Figure 4 The time period from t0 to t1 is shown in the figure. Figure 5 The figure is a schematic diagram of the first type of steady-state switching mode of the driving power supply provided in the embodiment of this application.
[0077] The magnetizing inductance Lm of transformer T is connected in parallel with the primary winding L of transformer T. When transformer T is working, the magnetizing inductance Lm generates the main magnetic flux and transfers energy.
[0078] like Figure 5 As shown, during the time interval from t0 to t1, the first switch S1 is turned on, the second switch S2 is turned off, and the resonant current i Lr For the positive half-wave of a sine wave, the resonant current i Lr The current flows to the first terminal of the primary winding L of transformer T and the first terminal of the magnetizing inductance Lm of transformer T; the first diode D1 and the second diode D2 are turned on, and the third diode D3 is turned off. The primary voltage of transformer T is clamped to n*Vo1, that is, the voltage of the magnetizing inductance Lm is clamped to n*Vo1, and the magnetizing inductance Lm does not participate in resonance; wherein, the first output voltage Vo1 is equal to the second output voltage Vo2, and the first output voltage Vo3 is equal to the negative third output voltage Vo3. At this time, the rising slope of the magnetizing current of transformer T is fixed and slow, and the magnetizing current of transformer T is less than the resonant current i. Lr Resonant capacitor C r With resonant inductor L k Resonance, resonant current i at time t1 Lr It is equal to the excitation current of transformer T.
[0079] Figure 5 The rest of the middle part and Figure 3 Same, see Figure 3 The description will not be repeated here.
[0080] like Figure 4 For the time period t1 to t2 shown, please refer to [link / reference]. Figure 6 The figure is a schematic diagram of the second steady-state switching mode of the driving power supply provided in the embodiment of this application.
[0081] like Figure 6As shown, during the time interval t1 to t2, the first switch S1 is turned on, the second switch S2 is turned off, and the excitation current is equal to the resonant current i. Lr Resonant current i Lr The current flows to the first terminal of the magnetizing inductance Lm of transformer T. No current flows through the primary winding L of transformer T. Diodes D1, D2, and D3 are all cut off. The voltage across the magnetizing inductance Lm is no longer clamped, and Lm participates in resonance, meaning the resonant capacitor Cr and resonant inductance L... k It resonates with the magnetizing inductor Lm.
[0082] Figure 6 The rest of the middle part and Figure 3 Same, see Figure 3 The description will not be repeated here.
[0083] like Figure 4 For the time period t2 to t3 shown, please refer to [link / reference]. Figure 7 The figure is a schematic diagram of the third steady-state switching mode of the driving power supply provided in the embodiment of this application.
[0084] like Figure 7 As shown, during the time period from t2 to t3, the first switch S1 is turned off, the second switch S2 is turned on, and the resonant current i Lr For the negative half-wave of a sine wave, the resonant current i Lr The current flows to the second terminal of the primary winding L of transformer T and the second terminal of the magnetizing inductance Lm of transformer T; the third diode D3 is turned on, while the first diode D1 and the second diode D2 are both turned off. The primary voltage of transformer T is clamped to -n*Vo2, that is, the voltage of the magnetizing inductance Lm is clamped to -n*Vo2, and the magnetizing inductance Lm does not participate in resonance; where the first output voltage Vo1 is equal to the second output voltage Vo2, and the first output voltage Vo1 is equal to the negative third output voltage Vo3, at this time the magnetizing current of transformer T decreases at a fixed and slow slope, and the magnetizing current is greater than the resonant current i. Lr Resonant inductor L k Resonance occurs with the resonant capacitor Cr, and the resonant current i at time t3. Lr It is equal to the excitation current of transformer T.
[0085] Figure 7 The rest of the middle part and Figure 3 Same, see Figure 3 The description will not be repeated here.
[0086] like Figure 4 For the time period t3 to t4 shown, please refer to [link / reference]. Figure 8 The figure is a schematic diagram of the fourth steady-state switching mode of the driving power supply provided in the embodiments of this application.
[0087] like Figure 8As shown, during the time period from t3 to t4, the first switch S1 is turned off, the second switch S2 is turned on, and the excitation current is equal to the resonant current i. Lr Resonant current i Lr The current flows to the second terminal of the magnetizing inductance Lm of transformer T. No current flows through the primary winding L of transformer T. Diodes D1, D2, and D3 are all cut off. The voltage across the magnetizing inductance Lm is no longer clamped, and Lm participates in resonance, meaning the resonant capacitance C... r Resonant inductor L k It resonates with the magnetizing inductor Lm.
[0088] Figure 8 The rest of the middle part and Figure 3 Same, see Figure 3 The description will not be repeated here.
[0089] The above describes the case where the switching frequency fs is less than the resonant frequency fr. The following section, with reference to the attached diagram, explains the working principle when the switching frequency fs is greater than the resonant frequency fr.
[0090] See Figure 9 This figure is a schematic diagram of the steady-state circuit waveform of the second type of driving power supply provided in an embodiment of this application. Figure 9 The middle waveform part is the same Figure 4 Partial, see Figure 4 The description will not be repeated here.
[0091] like Figure 9 The time period from t0 to t1 is shown in the figure. Figure 10 This figure is a schematic diagram of the fifth steady-state switching mode of the driving power supply provided in the embodiments of this application.
[0092] like Figure 10 As shown, during the time interval from t0 to t1, the first switch S1 is turned on, the second switch S2 is turned off, and the resonant current i Lr For the positive half-wave of a sine wave, the resonant current i Lr The current flows to the first terminal of the primary winding L of transformer T and the first terminal of the magnetizing inductance Lm of transformer T; the first diode D1 and the second diode D2 are turned on, and the third diode D3 is turned off. The primary voltage of transformer T is clamped to n*Vo1, that is, the voltage of the magnetizing inductance Lm is clamped to n*Vo1, and the magnetizing inductance Lm does not participate in resonance; wherein, the first output voltage Vo1 is equal to the second output voltage Vo2, and the first output voltage Vo3 is equal to the negative third output voltage Vo3. At this time, the rising slope of the magnetizing current of transformer T is fixed and slow, and the magnetizing current of transformer T is less than the resonant current i. Lr Resonant capacitor C r With resonant inductor L k Resonance, resonant current i at time t1 LrIt is equal to the excitation current of transformer T.
[0093] Figure 10 The rest of the middle part and Figure 3 Same, see Figure 3 The description will not be repeated here.
[0094] like Figure 9 For the time period t1 to t2 shown, please refer to [link / reference]. Figure 11 This figure is a schematic diagram of the sixth steady-state switching mode of the driving power supply provided in the embodiments of this application.
[0095] like Figure 11 As shown, during the time period from t1 to t2, the first switch S1 is turned off, the second switch S2 is turned on, and the resonant current i Lr For the negative half-wave of a sine wave, the resonant current i Lr The current flows to the second terminal of the primary winding L of transformer T and the second terminal of the magnetizing inductance Lm of transformer T; the third diode D3 is turned on, while the first diode D1 and the second diode D2 are turned off. The primary voltage of transformer T is clamped to -n*Vo2, that is, the voltage of the magnetizing inductance Lm is clamped to -n*Vo2, and the magnetizing inductance Lm does not participate in resonance; where the first output voltage Vo1 is equal to the second output voltage Vo2, and the first output voltage Vo1 is equal to the negative third output voltage Vo3, at this time the magnetizing current of transformer T decreases at a fixed and slow slope, and the magnetizing current is greater than the resonant current i. Lr Resonant inductor L k With resonant capacitor C r Resonance, resonant current i at time t2 Lr It is equal to the excitation current of transformer T.
[0096] Figure 11 The rest of the middle part and Figure 3 Same, see Figure 3 The description will not be repeated here.
[0097] The primary-side circuit of the driving power supply provided in this application embodiment includes a first switching transistor and a second switching transistor. The first output terminal of the primary-side circuit is connected to the first terminal of the primary winding through a series resonant capacitor and a resonant inductor. The second terminal of the primary winding is connected to the second output terminal of the primary-side circuit. The first and second switches are complementary in conduction during the switching cycle. The primary-side circuit of the driving power supply provided in this application embodiment includes two complementary switching transistors. During the switching cycle, the resonant circuit resonates, enabling energy transfer between the primary and secondary windings of the transformer.
[0098] The following section, with reference to the accompanying diagram, describes the implementation method when the primary circuit is a full-bridge circuit and the switching transistor is a MOSFET.
[0099] See Figure 12This figure is a schematic diagram of the fourth type of driving power supply provided in the embodiments of this application.
[0100] The primary-side circuit 100 of the driving power supply provided in this application embodiment is a full-bridge circuit, which includes a first switch S1, a second switch S2, a third switch S3, and a fourth switch S4. The first switch S1 and the second switch S2 are connected in series to form a first bridge arm connected to both ends of the DC source Vin, and the third switch S3 and the fourth switch S4 are connected in series to form a second bridge arm connected to both ends of the DC source Vin.
[0101] The midpoint of the first bridge arm is the first output terminal of the primary circuit 100, and the first output terminal is connected to a resonant capacitor C in series. r and resonant inductance L k The first end of the primary winding L is connected, the midpoint of the second bridge arm is the second output terminal of the primary circuit 100, and the second end of the primary winding L is connected to the second output terminal of the primary circuit 100; the first switch S1 and the fourth switch S4 are turned on simultaneously, the second switch S2 and the third switch S3 are turned on simultaneously, and the turn-on times of the first switch S1 and the second switch S2 are complementary. For example, in one possible implementation, the first switch S1 and the fourth switch S4 are turned on in the positive half-cycle of the switching cycle, the second switch S2 and the third switch S3 are turned on in the negative half-cycle of the switching cycle, and the dead time is ignored.
[0102] Figure 12 The operating effects of the first switch S1 and the fourth switch S4 are equivalent. Figure 3 The effect of the operation of the first switch S1 in the middle Figure 12 The operating effects of the second switch S2 and the third switch S3 are equivalent. Figure 3 The operating effect of the second switch S2 is described in detail in the above embodiments, and will not be repeated here.
[0103] Based on the driving power supply provided in the above embodiments, this application also provides a power converter, which will be described in detail below with reference to the accompanying drawings.
[0104] See Figure 13 The figure is a schematic diagram of the first power converter provided in the embodiment of this application.
[0105] The power converter provided in this application includes the drive power supply 1000 described in any of the above embodiments, and also includes a plurality of power transistors. The number of power transistors can be N, and the N power transistors correspond one-to-one with the output terminals of the N secondary circuits of the drive power supply 1000. The output terminals of the N secondary circuits of the drive power supply are used to supply power to the corresponding power transistors, where N is an integer greater than or equal to 2.
[0106] When N power transistors are used as active devices, they require power from a driver power supply 1000. The driver power supply 1000 includes N outputs, and each output circuit of the driver power supply 1000 supplies power to the corresponding power transistor, ensuring the power supply requirements of the power transistors.
[0107] The power converter provided in this application includes the drive power supply described in any of the above embodiments, and also includes multiple power transistors. The secondary circuit of the drive power supply includes only a single diode, which reduces the number of diodes and capacitors in the secondary circuit. The overall hardware circuit structure of the drive power supply is simple, which in turn simplifies the hardware circuit of the entire power converter.
[0108] Based on the driving power supply provided in the above embodiments, this application also provides a control method for the driving power supply, which will be described in detail below with reference to the accompanying drawings.
[0109] See Figure 14 The figure is a flowchart of a first driving power supply control method provided in an embodiment of this application.
[0110] The control method for the drive power supply provided in this application includes:
[0111] S1501: Controls the first set of switching transistors in the primary circuit of the drive power supply to turn on and the second set of switching transistors to turn off, so that the current in the resonant circuit flows from the primary circuit to the primary winding of the transformer.
[0112] The primary winding of the transformer is connected to the output terminal of the primary circuit through a resonant circuit; the transformer includes multiple secondary windings, which are connected to corresponding secondary circuits; the secondary circuits include diodes, and the anodes of some diodes in the secondary circuits are connected to the same-name terminal of the corresponding secondary winding, while the anodes of the diodes in the remaining secondary circuits are connected to the opposite-name terminal of the corresponding secondary winding.
[0113] S1502: Controls the first set of switches in the primary circuit of the drive power supply to turn off and the second set of switches to turn on, so that the current in the resonant circuit flows from the primary winding of the transformer to the primary circuit.
[0114] The driving power supply control method provided in this application first controls the first set of switches in the primary circuit to be turned on and the second set of switches to be turned off, so that the current in the resonant circuit flows from the primary circuit to the primary winding of the transformer; then, it controls the first set of switches in the primary circuit to be turned off and the second set of switches to be turned on, so that the current in the resonant circuit flows from the primary winding of the transformer to the primary circuit, and the driving power supply provides stable power support to the subsequent load. The resonant circuit can reduce the capacitance value of the primary circuit, and the secondary circuit only includes a single diode, which can reduce the complexity of the secondary circuit.
[0115] The embodiments of this application do not specifically limit the structure of the primary circuit, as long as it can convert the DC power from the DC source into AC power. For example, the primary circuit is a half-bridge circuit or a full-bridge circuit. The first output terminal of the primary circuit is connected to the first terminal of the primary winding through a series resonant capacitor and a resonant inductor, and the second terminal of the primary winding is connected to the second output terminal of the primary circuit.
[0116] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. Regarding the methods disclosed in the embodiments, since they correspond to the product embodiments disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the description of the product embodiments.
[0117] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A driving power supply, characterized in that, include: Primary circuit, transformer and multiple secondary circuits; The primary winding of the transformer is connected to the output terminal of the primary circuit through a resonant circuit, and the input terminal of the primary circuit is used to connect to a DC source. The secondary circuit is connected to the corresponding secondary winding; The secondary circuit includes diodes, with the anodes of some diodes in the secondary circuit connected to the same-name terminals of the secondary winding, and the anodes of the diodes in the remaining secondary circuits connected to the opposite-name terminals of the secondary winding.
2. The driving power supply according to claim 1, characterized in that, The resonant circuit includes a resonant capacitor and a resonant inductor, wherein the resonant inductor is an external inductor or the leakage inductance of the transformer; The ratio of the resonant frequency of the resonant circuit to the switching frequency of the primary circuit is less than a preset value.
3. The driving power supply according to claim 2, characterized in that, The primary-side circuit is a half-bridge circuit or a full-bridge circuit; The first output terminal of the primary circuit is connected to the first terminal of the primary winding through the resonant capacitor and the resonant inductor connected in series, and the second terminal of the primary winding is connected to the second output terminal of the primary circuit.
4. The driving power supply according to any one of claims 1-3, characterized in that, The secondary circuit also includes an output capacitor; When the anode of the diode is connected to the same-name terminal of the secondary winding, the cathode of the diode is connected to the first terminal of the output capacitor, and the second terminal of the output capacitor is connected to the opposite-name terminal of the corresponding secondary winding.
5. The driving power supply according to any one of claims 1-3, characterized in that, The secondary circuit also includes an output capacitor; When the anode of the diode is connected to the opposite terminal of the secondary winding, the cathode of the diode is connected to the first terminal of the output capacitor, and the second terminal of the output capacitor is connected to the same terminal of the corresponding secondary winding.
6. The driving power supply according to any one of claims 1-3, characterized in that, The absolute values of the output voltages of the multiple secondary circuits are the same.
7. The driving power supply according to any one of claims 1-3, characterized in that, The output voltage of the secondary circuit is less than the voltage of the DC source.
8. A power converter, characterized in that, include: The drive power supply according to any one of claims 1-7 further includes a plurality of power transistors; The output terminals of the multiple secondary circuits of the driving power supply are used to supply power to the corresponding power transistors.
9. A control method for a drive power supply, characterized in that, include: The first set of switching transistors in the primary circuit of the drive power supply is turned on and the second set of switching transistors is turned off, so that the current in the resonant circuit flows from the primary circuit to the primary winding of the transformer. The primary winding of the transformer is connected to the output terminal of the primary circuit through a resonant circuit; the transformer includes multiple secondary windings, and the secondary windings are connected to corresponding secondary circuits; the secondary circuit includes diodes, and the anodes of the diodes in some of the secondary circuits are connected to the same-name terminals of the corresponding secondary windings, while the anodes of the diodes in the remaining secondary circuits are connected to the opposite-name terminals of the corresponding secondary windings. The first set of switches in the primary circuit of the drive power supply is turned off, and the second set of switches is turned on, so that the current in the resonant circuit flows from the primary winding of the transformer to the primary circuit.
10. The control method according to claim 9, characterized in that, The primary-side circuit is a half-bridge circuit or a full-bridge circuit; The first output terminal of the primary circuit is connected to the first terminal of the primary winding through the resonant capacitor and the resonant inductor connected in series, and the second terminal of the primary winding is connected to the second output terminal of the primary circuit.