Dual-mode switching power supply circuit, source-load all-in-one machine and power supply test system

Abstract

The utility model discloses a dual-mode switching power supply circuit, a source-loaded all-in-one machine and a power supply test system. The circuit comprises a first end; a first bridge arm and a second bridge arm; one end of the first capacitor is connected with the midpoint of the second bridge arm through a first inductor; one end of the first switch is connected with the midpoint of the first bridge arm through the second inductor, the other end of the first switch is connected with one end of the first capacitor, a first moving contact of the second switch is connected with the midpoint of the first bridge arm through the second inductor, and a second moving contact of the second switch is connected with the negative electrode of the first end; a static contact of the second switch is connected with the other end of the first capacitor; and the controller enables the power supply circuit to be switched to a direct current mode or an alternating current mode by controlling the switching of the first switch and the second switch. Switching between a direct current mode and an alternating current mode can be achieved, different test requirements are met, the size is small, and cost is low.

Description

Technical Field

[0001] This application relates to the field of power supply, and in particular to a dual-mode switching power supply circuit, a source-carrier integrated unit, and a power supply testing system. Background Technology

[0002] The H-bridge inverter circuit is a core topology for converting direct current (DC) to alternating current (AC), widely used in uninterruptible power supplies (UPS), grid-connected photovoltaic inverters, motor drives, and other fields. Traditional H-bridge inverters generate a sinusoidal AC voltage at the output by controlling the pulse width modulation (PWM) signals of four switching transistors. The Buck converter is a classic DC-DC converter used to reduce higher DC voltages to lower required DC voltages, and is widely used in switching power supplies, voltage regulators, and other applications.

[0003] In power supply testing applications, depending on the load or power supply under test, AC power output is required in some cases, and DC power output is required in others. The traditional solution is to use separate inverters and Buck converters to address different testing needs, but this increases system size and cost. Utility Model Content

[0004] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a dual-mode switching power supply circuit, a source-carrier integrated unit, and a power supply testing system, which can realize the switching between DC mode and AC mode to meet different testing needs, and is small in size and low in cost.

[0005] A dual-mode switching power supply circuit according to an embodiment of the first aspect of this application, the power supply circuit comprising:

[0006] First end;

[0007] The first bridge arm and the second bridge arm, the positive terminals of the first bridge arm and the second bridge arm are both connected to the positive terminal of the first end, and the negative terminals of the first bridge arm and the second bridge arm are both connected to the negative terminal of the first end;

[0008] A first capacitor, one end of which is connected to the midpoint of the second bridge arm via a first inductor;

[0009] A first switch and a second switch, one end of the first switch is connected to the midpoint of the first bridge arm through a second inductor, the other end of the first switch is connected to one end of the first capacitor, the first moving contact of the second switch is connected to the midpoint of the first bridge arm through a second inductor, the second moving contact of the second switch is connected to the negative terminal of the first end, and the stationary contact of the second switch is connected to the other end of the first capacitor;

[0010] The second terminal is connected in parallel with the first capacitor;

[0011] A controller, which is connected to the control terminals of the first bridge arm and the second bridge arm, as well as the control terminals of the first switch and the second switch;

[0012] The controller switches the power circuit to DC mode or AC mode by controlling the operation of the first switch and the second switch.

[0013] According to some embodiments of this application, the power supply circuit further includes a voltage sampling circuit, which is used to sample the voltage at the first terminal and the voltage at the second terminal, and the signal output terminal of the voltage sampling circuit is connected to the controller.

[0014] According to some embodiments of this application, the power supply circuit further includes a current sampling circuit, which is used to sample the current of the first bridge arm, the current of the second bridge arm, and the current of the second terminal, and the signal output terminal of the current sampling circuit is connected to the controller.

[0015] According to a second aspect embodiment of this application, the integrated source and carrier unit includes a PFC circuit, an isolated DC / DC circuit, and a dual-mode switching power supply circuit as described in the first aspect embodiment, connected in sequence.

[0016] According to some embodiments of this application, the isolated DC / DC circuit employs a full-bridge LLC circuit.

[0017] A power supply testing system according to a third aspect of this application includes a power supply under test and a source-carrier integrated machine as described in a second aspect embodiment, wherein the power supply under test and the source-carrier integrated machine are connected.

[0018] The dual-mode switching power supply circuit, source-carrier integrated unit, and power supply testing system according to the embodiments of this application have at least the following beneficial effects:

[0019] In this embodiment, by setting a first switch and a second switch between the first bridge arm, the second bridge arm, and the second terminal, the controller can control the switching of the first switch and the second switch to make the circuit operate in AC mode or DC mode. When the controller controls the first switch to open and the first moving contact of the second switch is connected to the stationary contact, the midpoint of the first bridge arm is connected to the negative terminal of the second terminal through the second inductor, and the midpoint of the second bridge arm is connected to the positive terminal of the second terminal through the first inductor. At this time, the power supply circuit is in AC mode, and AC power can be output or input through the second terminal. When the controller controls the first switch to close and the second moving contact of the second switch is connected to the stationary contact, the negative terminal of the first terminal is connected to the negative terminal of the second terminal, and the midpoint of the second bridge arm is connected to the positive terminal of the second terminal through the first inductor. At this time, the power supply circuit is in DC mode, and DC power can be output or input through the second terminal. This application can realize the switching between DC mode and AC mode, meet different testing needs, and is small in size and low in cost.

[0020] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0021] The present application will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0022] Figure 1 This is a circuit diagram of a power supply circuit for dual-mode switching in AC mode, as shown in the embodiments of this application.

[0023] Figure 2 This is a circuit diagram of a power supply circuit for dual-mode switching in DC mode, as shown in the embodiments of this application.

[0024] Figure 3 This is a schematic diagram of the control loop of the controller in AC mode in the embodiments of this application;

[0025] Figure 4 This is a schematic diagram of the control loop of the controller in DC mode in the embodiments of this application;

[0026] Figure 5 This is a circuit diagram of the source carrier integrated machine in the embodiments of this application. Detailed Implementation

[0027] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0028] In the description of this application, it should be understood that the orientation descriptions, such as up, down, etc., are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0029] In the description of this application, "multiple" refers to two or more. The use of "first" and "second" is for the purpose of distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of technical features indicated, or the order in which the technical features are indicated.

[0030] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0031] Reference Figure 1 and Figure 2 As shown, a dual-mode switching power supply circuit includes:

[0032] First end;

[0033] The first bridge arm and the second bridge arm, the positive terminals of the first bridge arm and the second bridge arm are both connected to the positive terminal of the first end, and the negative terminals of the first bridge arm and the second bridge arm are both connected to the negative terminal of the first end.

[0034] The first capacitor, one end of which is connected to the midpoint of the second bridge arm through the first inductor;

[0035] A first switch and a second switch, one end of the first switch is connected to the midpoint of the first bridge arm through a second inductor, the other end of the first switch is connected to one end of the first capacitor, the first moving contact of the second switch is connected to the midpoint of the first bridge arm through a second inductor, the second moving contact of the second switch is connected to the negative terminal of the first end, and the stationary contact of the second switch is connected to the other end of the first capacitor.

[0036] The second terminal is connected in parallel with the first capacitor.

[0037] The controller is connected to the control terminals of the first bridge arm and the second bridge arm, as well as the control terminals of the first switch and the second switch.

[0038] The controller switches the power circuit to DC or AC mode by controlling the switching of the first and second switches.

[0039] In this embodiment, by setting a first switch and a second switch between the first bridge arm, the second bridge arm, and the second terminal, the controller can control the switching of the first switch and the second switch to make the circuit operate in AC mode or DC mode. When the controller controls the first switch to open and the first moving contact of the second switch is connected to the stationary contact, the midpoint of the first bridge arm is connected to the negative terminal of the second terminal through the second inductor, and the midpoint of the second bridge arm is connected to the positive terminal of the second terminal through the first inductor. At this time, the power supply circuit is in AC mode, and AC power can be output or input through the second terminal. When the controller controls the first switch to close and the second moving contact of the second switch is connected to the stationary contact, the negative terminal of the first terminal is connected to the negative terminal of the second terminal, and the midpoint of the second bridge arm is connected to the positive terminal of the second terminal through the first inductor. At this time, the power supply circuit is in DC mode, and DC power can be output or input through the second terminal. This application can realize the switching between DC mode and AC mode, meet different testing needs, and is small in size and low in cost.

[0040] It should be noted that in this embodiment, the first terminal and the second terminal can be used as either input or output terminals. When the first terminal is used as an input terminal, the second terminal is used as an output terminal; when the second terminal is used as an input terminal, the first terminal is used as an output terminal. The first terminal serves as a fixed DC side, and the second terminal can serve as either a DC side or an AC side depending on the mode. In DC mode, the second terminal serves as a DC side, and in AC mode, the second terminal serves as an AC side.

[0041] Specifically, the first bridge arm is composed of MOSFETs Q1 and Q3 connected in series, and the second bridge arm is composed of MOSFETs Q2 and Q4 connected in series. The common terminal of MOSFETs Q1 and Q3 serves as the midpoint of the first bridge arm, and the common terminal of MOSFETs Q2 and Q4 serves as the midpoint of the second bridge arm. The common terminal of MOSFETs Q1 and Q3 is connected to the first moving contact of the second switch and one end of the first switch through the second inductor L2. The second moving contact of the second switch is connected to the first end and the negative terminals of the two bridge arms. The common terminal of MOSFETs Q2 and Q4 is connected to one end of the first capacitor C1 through the first inductor L1. The stationary contact of the second switch is connected to the other end of the first capacitor C1. The two ends of the first capacitor C1 serve as the second end.

[0042] The aforementioned first and second switches can be mechanical switches, such as mechanical relays, or semiconductor switches, such as MOSFETs. Taking mechanical switches as an example, a single-pole single-throw switch can be used as the first switch, and a single-pole double-throw switch as the second switch, or a double-pole double-throw switch can be used directly. In this embodiment, the first and second switches are integrated into a single double-pole double-throw switch S1. The first and second switches correspond to a set of moving and stationary contacts of the double-pole double-throw switch, and one moving contact of the first switch is left unconnected. The controller switches between the two circuit modes by controlling the up and down switching of the knife switch in the double-pole double-throw switch S1.

[0043] The controller connected to the control terminals of the first and second bridge arms refers to the controller being connected to the gates of MOSFETs Q1-Q4. By sending PWM waves, it controls the conduction of MOSFETs Q1-Q4, thereby controlling the output voltage and current of the power supply circuit.

[0044] It should be noted that the AC mode in this application refers to the DC-AC mode, that is, the first end of the circuit is connected to DC and the second end is connected to AC, and the circuit can realize the conversion between AC and DC; the DC mode in this application refers to the DC-DC mode, that is, the first end and the second end of the circuit are both connected to DC, and the circuit can realize the conversion between DC and DC with different voltages and power.

[0045] The working principles of AC and DC modes are explained in detail below with reference to the circuit:

[0046] Communication mode: Reference Figure 1 As shown, when the double-pole double-throw switch S1 is switched to the up position, the midpoint of the first bridge arm is connected to the negative terminal of the second end through the second inductor L2, and the midpoint of the second bridge arm is connected to the positive terminal of the second end through the first inductor L1. At this time, the circuit forms a full-bridge inverter. The controller uses sinusoidal pulse width modulation (SPWM) to control the conduction and turn-off of four switching transistors: MOSFETs Q1, Q2, Q3, and Q4. The controller generates a sinusoidal AC voltage of the required amplitude and frequency across the first capacitor C1, i.e., the second terminal, by adjusting the amplitude and frequency of the modulation wave.

[0047] It should be noted that in AC mode, the second terminal can be used as both an output and an input terminal. Taking the first terminal connected to the power grid and the second terminal connected to the test power supply or load as an example, when the output port voltage VO is less than the controller's set voltage, the system operates in inverter mode and outputs energy to the outside. When the output port voltage VO is greater than the controller's set voltage, the system operates in rectification mode and feeds energy back to the power grid.

[0048] DC Mode: When the double-pole double-throw switch S1 is switched to the down position, the midpoint of the first bridge arm is connected to the positive terminal of the second end through the second inductor L2, and the midpoint of the second bridge arm is connected to the positive terminal of the second end through the first inductor L1. At this time, the circuit forms a two-phase interleaved buck-boost circuit, thereby realizing DC output. The controller adopts a two-phase interleaved control strategy to control the conduction and turn-off of four switching transistors: MOSFETs Q1, Q2, Q3, and Q4. Among them, MOSFETs Q1 and Q3 and the second inductor L2 form the B-phase circuit, and MOSFETs Q2 and Q4 and the first inductor L1 form the A-phase circuit. The two phases are interleaved by 180 degrees. By adjusting the amplitude and frequency of the modulation wave, a DC voltage of the required amplitude is generated across the first capacitor C1.

[0049] It should be noted that in DC mode, the second terminal can be used as both an output and an input terminal. Taking the first terminal connected to the power grid and the second terminal connected to the test power supply or load as an example, when the output port voltage VO is less than the controller's set voltage, the system operates in buck mode, which is the source mode, and outputs energy to the outside. When the output port voltage VO is greater than the controller's set voltage, the system operates in boost mode, which is the load mode, and feeds energy back to the power grid.

[0050] In this embodiment, the presence of the double-pole double-throw switch S1 enables compatibility between single-phase H-bridge inverter and two-phase interleaved buck converter. Connecting the double-pole double-throw switch S1 outputs AC power, while disconnecting it outputs DC power, allowing the controller to switch between AC and DC modes. Using the same set of power switches and most passive components achieves both inverter and buck functions, significantly improving hardware utilization and reducing component count, system size, and cost. A simple mode selection switch enables rapid and smooth switching between the two operating modes, adapting to different load requirements.

[0051] In some implementations, the power supply circuit further includes a voltage sampling circuit for sampling the voltage at the first terminal and the voltage at the second terminal, and the signal output terminal of the voltage sampling circuit is connected to the controller.

[0052] In this embodiment, the voltage at the first terminal and the voltage at the second terminal are collected by a voltage sampling circuit, so that the controller can obtain the input voltage and output voltage of the circuit. Based on the set voltage and the input voltage and output voltage, the voltage loop is controlled to ensure the stability of the output voltage.

[0053] refer to Figure 3As shown, the voltage loop control process in AC mode is as follows: The controller subtracts the set voltage Vset from the acquired output voltage VO, and after error amplification and SPWM modulation, generates the driving waveforms of MOSFETs Q1 and Q4, as well as the driving waveforms of MOSFETs Q2 and Q3, which are used to drive the corresponding MOSFETs. The waveforms of MOSFETs Q1 and Q4 are the same, the waveforms of MOSFETs Q2 and Q3 are the same, and the waveforms of MOSFETs Q1 and Q2 are complementary.

[0054] refer to Figure 4 As shown, the voltage loop control process in DC mode is as follows: the controller subtracts the set voltage Vset from the output voltage VO. After error amplification, the voltage is then passed through the corresponding PWM modulation module 1 and PWM modulation module 2 to generate the driving waveforms of MOSFETs Q1 to Q4. The phases of the driving waveforms of MOSFETs Q1 and Q2 are interleaved by 180 degrees, so that the output voltage VO = V_SET, thereby generating a stable output voltage.

[0055] In some implementations, the power supply circuit further includes a current sampling circuit for sampling the current of the first bridge arm, the current of the second bridge arm, and the current of the second terminal. The signal output terminal of the current sampling circuit is connected to the controller.

[0056] In this embodiment, the current of the first bridge arm, the current of the second bridge arm, and the current of the second terminal are collected by the current sampling circuit, so that the controller can obtain the branch current of the bridge arm and the total output current and perform current regulation. This can realize functions such as current sharing and wave-by-wave current limiting, thereby improving the reliability of the circuit.

[0057] Specifically, the current of the second bridge arm refers to the current of phase A, i.e. the current of the first inductor L1, and the current of the first bridge arm refers to the current of phase B, i.e. the current of the second inductor L2.

[0058] In AC mode, the inductor current of phase A and the inductor current of phase B are currents with opposite directions and the same amplitude. The controller can use only one of the data for wave-by-wave current limiting.

[0059] In DC mode, the reference Figure 4 As shown, IA is the inductor current of phase A and IB is the inductor current of phase B. IA and IB are connected in parallel, so IA and IB are used for parallel current sharing. The controller generates a current sharing loop to control IA=IB.

[0060] refer to Figure 5 As shown, this application also relates to a source-carrier integrated machine, including a PFC circuit, an isolated DC / DC circuit, and a dual-mode switching power supply circuit of the above embodiment connected in sequence.

[0061] In some implementations, the isolated DC / DC circuit employs a full-bridge LLC circuit.

[0062] Specifically, the PFC circuit consists of MOSFETs Q13-Q16, inductor L4, and capacitor C4, forming a bidirectional PFC circuit. The full-bridge LLC circuit consists of MOSFETs Q5-Q12, inductor L3, capacitor C2, transformer T1, and capacitor C3, forming a single-phase full-bridge LLC circuit. The aforementioned source-carrier integrated circuit has two operating modes: source mode and carrier mode. One end of the PFC circuit is connected to the power grid, and the other end is connected to one end of the full-bridge LLC circuit. The other end of the full-bridge LLC circuit is connected to the dual-mode switching power supply circuit of this application. The second end of the dual-mode switching power supply circuit serves as the output terminal and is connected to the device under test (DUT), which can be either a power supply under test or a load under test.

[0063] In source mode, the aforementioned source-carrier integrated unit outputs either a DC or AC voltage from the grid's AC input voltage. In carrier mode, it feeds the output AC / DC input voltage back to the grid. The bidirectional PFC circuit rectifies the grid's AC voltage into DC in source mode and feeds the DC voltage back to the grid in carrier mode. The full-bridge LLC circuit provides electrical isolation, enabling bidirectional DC / DC transmission. The dual-mode switching power supply circuit of this application switches between AC and DC output modes depending on the usage conditions.

[0064] This application also relates to a power supply testing system, including a power supply under test and a source-carrier integrated machine as described in the above embodiments, wherein the power supply under test and the source-carrier integrated machine are connected.

[0065] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application.

Claims

1. A dual-mode switching power supply circuit, characterized in that, The power supply circuit includes: First end; The first bridge arm and the second bridge arm, the positive terminals of the first bridge arm and the second bridge arm are both connected to the positive terminal of the first end, and the negative terminals of the first bridge arm and the second bridge arm are both connected to the negative terminal of the first end; A first capacitor, one end of which is connected to the midpoint of the second bridge arm via a first inductor; A first switch and a second switch, one end of the first switch is connected to the midpoint of the first bridge arm through a second inductor, the other end of the first switch is connected to one end of the first capacitor, the first moving contact of the second switch is connected to the midpoint of the first bridge arm through a second inductor, the second moving contact of the second switch is connected to the negative terminal of the first end, and the stationary contact of the second switch is connected to the other end of the first capacitor; The second terminal is connected in parallel with the first capacitor; A controller, which is connected to the control terminals of the first bridge arm and the second bridge arm, as well as the control terminals of the first switch and the second switch; The controller switches the power supply circuit to DC mode or AC mode by controlling the switching of the first switch and the second switch.

2. The dual-mode switching power supply circuit according to claim 1, characterized in that, The power supply circuit also includes a voltage sampling circuit, which is used to sample the voltage at the first terminal and the voltage at the second terminal. The signal output terminal of the voltage sampling circuit is connected to the controller.

3. The dual-mode switching power supply circuit according to claim 1, characterized in that, The power supply circuit further includes a current sampling circuit, which is used to sample the current of the first bridge arm, the current of the second bridge arm, and the current of the second terminal. The signal output terminal of the current sampling circuit is connected to the controller.

4. A source-carrier integrated machine, characterized in that, It includes a PFC circuit, an isolated DC / DC circuit, and a dual-mode switching power supply circuit as described in any one of claims 1 to 3, connected in sequence.

5. The source-carrier integrated machine according to claim 4, characterized in that, The isolated DC / DC circuit uses a full-bridge LLC circuit.

6. A power supply testing system, characterized in that, It includes a power supply under test and the source-carrier integrated machine as described in claim 4 or 5, wherein the power supply under test and the source-carrier integrated machine are connected.

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