Interleaved stacked dc-dc bidirectional power converter

Abstract

The utility model provides a kind of interlaced superimposed DC-DC bidirectional power converter, because including: first capacitor, second capacitor, positive pole is connected with the negative pole of first capacitor, third capacitor, positive pole is connected with the negative pole of second capacitor;First inductor, first end is connected with the positive pole of second capacitor;Second inductor, first end is connected with the negative pole of second capacitor;First switch tube, negative pole is connected with the second end of first inductor, positive pole is connected with the positive pole of first capacitor;Second switch tube, positive pole is connected with the positive pole of second capacitor, negative pole is connected with the negative pole of second capacitor;Third switch tube, positive pole is connected with the positive pole of second capacitor, negative pole is connected with the second end of second inductor;Fourth switch tube, positive pole is connected with the second end of second capacitor, negative pole is connected with the negative pole of third capacitor, so, the utility model will two sub-circuits interlaced superimposed and control switch on-off, realized efficient DC-DC voltage conversion, effectively reduce energy loss, maintain the stability of output voltage.

Description

Technical Field

[0001] This utility model relates to the field of integrated circuit technology, specifically to an interleaved DC-DC bidirectional power converter. Background Technology

[0002] As the global energy structure accelerates its transformation towards low-carbon, intelligent, and efficient directions, emerging industries such as new green data centers, electric vehicles, photovoltaic power generation, energy storage systems, and microgrids are developing rapidly, placing unprecedented performance demands on power electronic converters. In these application scenarios, bidirectional energy flow, wide-range input / output regulation, high conversion efficiency, and compact power density have become key technical indicators for power system design.

[0003] A DC-DC bidirectional converter is a power converter capable of bidirectional conversion of DC energy. It can transfer energy from renewable energy sources to energy storage devices, and simultaneously transmit stored energy back to loads or the power grid. This flexibility in bidirectional energy conversion enables energy storage and release, providing strong support for the regulation and optimization of energy systems. Currently, traditional DC-DC bidirectional converter topologies include Buck-Boost, Flyback, Half-Bridge, and Full-Bridge. While these topologies meet basic functional requirements to some extent, they still face challenges in high-frequency applications, such as high switching losses, difficulty in miniaturizing magnetic components, and difficulties in parallel current sharing, limiting their further application in high-power-density scenarios. Furthermore, the stability and dynamic response capabilities of existing control strategies in dealing with complex operating conditions (such as input / output voltage fluctuations and load abrupt changes) still need improvement. Utility Model Content

[0004] This invention was developed to solve the above-mentioned problems, and its purpose is to provide an interleaved DC-DC bidirectional power converter.

[0005] This invention provides an interleaved DC-DC bidirectional power converter, characterized by the following features: a first capacitor for boosting voltage; a second capacitor, with its positive terminal connected to the negative terminal of the first capacitor, for boosting voltage; a third capacitor, with its positive terminal connected to the negative terminal of the second capacitor, for boosting voltage; a voltage input terminal, with its positive terminal connected to the positive terminal of the second capacitor and its negative terminal connected to the negative terminal of the second capacitor, for inputting voltage; a first inductor, with its first terminal connected to the positive terminal of the second capacitor, for storing and releasing electrical energy; a second inductor, with its first terminal connected to the negative terminal of the second capacitor, for storing and releasing electrical energy; and a first switching transistor, with its negative terminal connected to the second terminal of the first inductor and its positive terminal connected to the positive terminal of the first capacitor, for controlling the circuit according to a signal. The circuit consists of four sub-circuits: a first inductor, a second capacitor, and a third inductor. The first inductor, the first switch, the second switch, and the first capacitor form the first sub-circuit, while the second inductor, the third switch, the fourth switch, and the second capacitor form the second sub-circuit.

[0006] The interleaved DC-DC bidirectional power converter provided by this utility model may also have the following features: it further includes: a first filter capacitor, the positive terminal of which is connected to the positive terminal of the voltage input terminal and the negative terminal of which is connected to the negative terminal of the voltage input terminal, for filtering out high-frequency noise and ripple in the input voltage; and a second filter capacitor, the positive terminal of which is connected to the positive terminal of the voltage output terminal and the negative terminal of which is connected to the negative terminal of the voltage output terminal, for filtering out high-frequency noise and ripple in the output voltage.

[0007] The interleaved DC-DC bidirectional power converter provided by this utility model may also have the following features: it further includes a control module that generates PWM signals based on the input voltage, output voltage, input current and output current provided by feedback sampling to control the first switch, the second switch, the third switch and the fourth switch.

[0008] The interleaved DC-DC bidirectional power converter provided by this utility model may also have the following features: when the first switch and the fourth switch are turned on and the second switch and the third switch are turned off, the first inductor releases electrical energy to the voltage output terminal, and the second inductor stores electrical energy from the voltage input terminal.

[0009] The interleaved DC-DC bidirectional power converter provided by this utility model may also have the following feature: when the second and third switches are turned on and the first and fourth switches are turned off, the second inductor releases electrical energy to the voltage output terminal, and the first inductor stores electrical energy from the voltage input terminal.

[0010] The interleaved DC-DC bidirectional power converter provided by this utility model may also include at least one third sub-circuit connected in series between the voltage input terminal and the voltage output terminal. The third sub-circuit includes: a fourth capacitor, the negative terminal of which is connected to the positive terminal of the voltage input terminal for boosting the voltage; a fifth capacitor, the negative terminal of which is connected to the positive terminal of the fourth capacitor and the positive terminal of which is connected to the voltage output terminal for boosting the voltage; a third inductor, the first terminal of which is connected to the positive terminal of the fourth capacitor for storing and releasing electrical energy; a fifth switch, the negative terminal of which is connected to the negative terminal of the fourth capacitor and the positive terminal of which is connected to the second terminal of the third inductor for controlling the circuit to switch on and off according to a signal; and a sixth switch, the negative terminal of which is connected to the second terminal of the third inductor and the positive terminal of which is connected to the positive terminal of the fifth capacitor and the positive terminal of the voltage output terminal respectively for controlling the circuit to switch on and off according to a signal.

[0011] The interleaved DC-DC bidirectional power converter provided by this utility model may also have the following feature: it further includes at least one fourth sub-circuit connected in series between the voltage input terminal and the voltage output terminal; the fourth sub-circuit includes: a sixth capacitor, the negative terminal of which is connected to the positive terminal of the voltage input terminal for boosting the voltage; a fourth inductor, the first terminal of which is connected to the negative terminal of the sixth capacitor for storing and releasing electrical energy; and a seventh switch, the negative terminal of which is connected to the second terminal of the fourth inductor, and the positive terminal of which is connected to the positive terminal of the sixth capacitor and the positive terminal of the voltage output terminal respectively, for controlling the circuit to turn on and off according to the signal.

[0012] The interleaved DC-DC bidirectional power converter provided by this utility model may also have the following features: a third sub-circuit and a fourth sub-circuit are connected in series between the voltage input terminal and the voltage output terminal. The number of the third sub-circuit is set according to the output voltage required by the voltage output terminal, and the number of the fourth sub-circuit is set according to the number of voltage output terminals.

[0013] Functions and effects of utility models

[0014] The interleaved DC-DC bidirectional power converter according to this utility model includes: a first capacitor for boosting voltage; a second capacitor, with its positive terminal connected to the negative terminal of the first capacitor, for boosting voltage; a third capacitor, with its positive terminal connected to the negative terminal of the second capacitor, for inputting voltage; a first inductor, with its first terminal connected to the positive terminal of the second capacitor, for storing and releasing electrical energy; a second inductor, with its first terminal connected to the negative terminal of the second capacitor, for storing and releasing electrical energy; a first switch, with its negative terminal connected to the second terminal of the first inductor and its positive terminal connected to the positive terminal of the first capacitor, for controlling the circuit's on / off state according to a signal; and a second switch, with its positive terminal connected to the positive terminal of the second capacitor and its negative terminal connected to the negative terminal of the second capacitor, for controlling the circuit's on / off state according to a signal. The circuit consists of two sub-circuits: a first inductor, a second switch, and a third capacitor. The first inductor, the first switch, the second switch, and the first capacitor form the first sub-circuit, while the second inductor, the third switch, the fourth switch, and the second capacitor form the second sub-circuit. Therefore, this interleaved DC-DC bidirectional power converter achieves efficient DC-DC voltage conversion by interleaving and controlling the switching of the two sub-circuits, effectively reducing energy loss and maintaining stable output voltage. Attached Figure Description

[0015] Figure 1 This is a circuit diagram of the interleaved DC-DC bidirectional power converter in Embodiment 1 of this utility model.

[0016] Figure 2 This is a waveform diagram of the DC-DC bidirectional power converter with interleaved superposition in Embodiment 1 of this utility model when simulating a 75V input.

[0017] Figure 3 This is a waveform diagram of the interleaved DC-DC bidirectional power converter in Embodiment 1 of this utility model when simulating a 240V input.

[0018] Figure 4 This is a control flowchart of the interleaved DC-DC bidirectional power converter in Embodiment 1 of this utility model.

[0019] Figure 5 This is a circuit diagram of a DC-DC bidirectional power converter with a single output capacitor connected in series in Embodiment 2 of this utility model.

[0020] Figure 6This is a circuit diagram of the multi-output capacitor-free series-connected DC-DC bidirectional power converter in Embodiment 3 of this utility model.

[0021] Figure 7 This is a circuit diagram of the DC-DC bidirectional power converter with multiple output capacitors connected in series in Embodiment 4 of this utility model.

[0022] Figure 8 This is a circuit diagram of the DC-DC bidirectional power converter reconstructed by a multi-output capacitor series switch in Embodiment 5 of this utility model.

[0023] Figure 9 This is a circuit diagram of the DC-DC converter cascaded half-bridge LLC resonant converter in Embodiment 5 of this utility model.

[0024] Figure 10 This is a circuit diagram of the multi-port LLC resonant converter with switch multiplexing in Embodiment 5 of this utility model.

[0025] Figure 11 This is a circuit diagram of the symmetrically adjustable multi-port LLC resonant converter with switch multiplexing in Embodiment 5 of this utility model.

[0026] Figure 12 This is a waveform diagram of the photovoltaic 70V input of the multi-port asymmetric LLC resonant converter with switch multiplexing in Embodiment 5 of this utility model.

[0027] Figure 13 This is a waveform diagram of the photovoltaic 130V input of the multi-port asymmetric LLC resonant converter with switch multiplexing in Embodiment 5 of this utility model.

[0028] Figure 14 This is a waveform diagram of the photovoltaic 90V input of the symmetrically adjustable multi-port LLC resonant converter with switch multiplexing in Embodiment 5 of this utility model.

[0029] Figure 15 This is a waveform diagram of the photovoltaic 45V input of the symmetrically adjustable multi-port LLC resonant converter with switch multiplexing in Embodiment 5 of this utility model. Detailed Implementation

[0030] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0031] To make the technical means, creative features, objectives and effects of this utility model easy to understand, the following embodiments, in conjunction with the accompanying drawings, will specifically illustrate the interleaved DC-DC bidirectional power converter of this utility model.

[0032] Example 1

[0033] Figure 1 This is a circuit diagram of the interleaved DC-DC bidirectional power converter in Embodiment 1 of this utility model.

[0034] like Figure 1 As shown, this embodiment provides an interleaved DC-DC bidirectional power converter, including: a first capacitor C1, a second capacitor C2, a third capacitor C3, a voltage input terminal Vin, a first inductor L1, a second inductor L2, a first switch S1, a second switch S2, a third switch S3, a fourth switch S4, a voltage output terminal Vout, a first filter capacitor Cin, a second filter capacitor Cout, and a control module.

[0035] In this embodiment, the switching transistor is a semiconductor device such as a MOSFET or an IGBT.

[0036] The first capacitor C1 is used to boost the voltage.

[0037] The positive terminal of the second capacitor C2 is connected to the negative terminal of the first capacitor C1, and is used to boost the voltage.

[0038] The positive terminal of the third capacitor C3 is connected to the negative terminal of the second capacitor C2, and is used to boost the voltage.

[0039] The positive terminal of the voltage input Vin is connected to the positive terminal of the second capacitor C2, and the negative terminal is connected to the negative terminal of the second capacitor C2, which is used for input voltage.

[0040] The first terminal of the first inductor L1 is connected to the positive terminal of the second capacitor C2, and is used to store and release electrical energy.

[0041] The first terminal of the second inductor L2 is connected to the negative terminal of the second capacitor C2, and is used to store and release electrical energy.

[0042] The negative terminal of the first switching transistor S1 is connected to the second terminal of the first inductor L1, and the positive terminal is connected to the positive terminal of the first capacitor C1, which is used to control the circuit to turn on and off according to the signal.

[0043] The positive terminal of the second switch S2 is connected to the positive terminal of the second capacitor C2, and the negative terminal is connected to the negative terminal of the second capacitor C2, which is used to control the circuit to turn on and off according to the signal.

[0044] The positive terminal of the third switch S3 is connected to the positive terminal of the second capacitor C2, and the negative terminal is connected to the second terminal of the second inductor L2, which is used to control the circuit to turn on and off according to the signal.

[0045] The positive terminal of the fourth switch S4 is connected to the second terminal of the second capacitor C2, and the negative terminal is connected to the negative terminal of the third capacitor C3, which is used to control the circuit to turn on and off according to the signal.

[0046] The positive terminal of the voltage output Vout is connected to the positive terminal of the first switching transistor S1, and the negative terminal is connected to the negative terminal of the fourth switching transistor S4, which is used to output voltage.

[0047] The first inductor L1, the first switch S1, the second switch S2 and the first capacitor C1 constitute the first sub-circuit, and the second inductor L2, the third switch S3, the fourth switch S4 and the second capacitor C2 constitute the second sub-circuit.

[0048] The positive terminal of the first filter capacitor Cin is connected to the positive terminal of the voltage input Vin, and the negative terminal is connected to the negative terminal of the voltage input Vin. It is used to filter out high-frequency noise and ripple in the input voltage.

[0049] The positive terminal of the second filter capacitor Cout is connected to the positive terminal of the voltage output terminal Vout, and the negative terminal is connected to the negative terminal of the voltage output terminal Vout. It is used to filter out high-frequency noise and ripple in the output voltage.

[0050] The control module generates PWM signals based on the input voltage, output voltage, input current, and output current signals provided by feedback sampling to control the first switch S1, the second switch S2, the third switch S3, and the fourth switch S4.

[0051] When the first switch S1 and the fourth switch S4 are turned on and the second switch S2 and the third switch S3 are turned off, the first inductor L1 releases electrical energy to the voltage output terminal Vout, and the second inductor L2 stores electrical energy from the voltage input terminal Vin.

[0052] When the second switch S2 and the third switch S3 are turned on and the first switch S1 and the fourth switch S4 are turned off, the second inductor L2 releases electrical energy to the voltage output terminal Vout, and the first inductor L1 stores electrical energy from the voltage input terminal Vin.

[0053] The circuit working principle of the interleaved DC-DC bidirectional power converter is as follows:

[0054] The control module (MCU) uses a closed-loop algorithm to calculate a suitable duty cycle based on the input voltage, output voltage, input current, and output current signals provided by feedback sampling. This generates a PWM signal to control the on / off states of the first switch S1, the second switch S2, the third switch S3, and the fourth switch S4. The first and second sub-circuits are connected in parallel and interleaved during operation. The first switch S1 and the fourth switch S4 are turned on and off at the same time, as are the second switch S2 and the third switch S3. The first switch S1 and the second switch S2 are turned on alternately, and the third switch S3 and the fourth switch S4 are turned on alternately. This allows the energy conversion processes of the two to complement each other, thereby achieving a smoother current and voltage waveform.

[0055] When the first switch S1 and the fourth switch S4 are turned off, and the second switch S2 and the third switch S3 are turned on, the second inductor L2 releases energy. The input voltage is then boosted by the first capacitor C1 and the second capacitor C2 before being output. At the same time, the first inductor L1 stores energy through the second switch S2.

[0056] When the second switch S2 and the third switch S3 are turned off, and the first switch S1 and the fourth switch S4 are turned on, the first inductor L1 releases energy, and the input voltage is output after being boosted by the first capacitor C1 and the second capacitor C2. At the same time, the second inductor L2 stores energy through the third switch S3.

[0057] Output voltage U out The output voltage U of the first sub-circuit d With the input capacitor voltage U of the second sub-circuit c The sum, the formula is as follows:

[0058] U out =U d +U c

[0059] The voltage gain formula for the sub-circuit is:

[0060]

[0061] Where D is the duty cycle.

[0062] According to the output voltage U of the first sub-circuit d With the input capacitor voltage U of the second sub-circuit c Substituting the relationship into the voltage gain formula of the above sub-circuit, we can obtain:

[0063]

[0064] Therefore, the input voltage U can be obtained. in With output voltage U outThe gain and the expression for duty cycle D:

[0065]

[0066] Based on the above principles, a simulation model was built with an input voltage of 75V-240V, an output voltage of 400V, an input capacitor of 220nF, an inductor of 500uH, and a filter capacitor of 47uF. This model simulated the operation of an interleaved DC-DC bidirectional power converter at input voltages of 75V and 240V.

[0067] Based on the above embodiments, simulation tests were performed on the topology of the interleaved DC-DC bidirectional power converter, and its parameters are shown in Table 1 below:

[0068] Main parameters of the prototype built in Table 1

[0069]

[0070]

[0071] Figure 2 This is a waveform diagram of the DC-DC bidirectional power converter with interleaved superposition in Embodiment 1 of this utility model when simulating a 75V input.

[0072] Figure 3 This is a waveform diagram of the interleaved DC-DC bidirectional power converter in Embodiment 1 of this utility model when simulating a 240V input.

[0073] like Figure 2 and Figure 3 As shown, the simulation results are as follows. Simulation tests were performed for input voltages of 75V and 240V respectively. The waveforms from top to bottom are the GS voltage of the first switch S1, the GS voltage of the fourth switch S4, and the output voltage U. out Output current I out The voltages across the first capacitor C1 and the second capacitor C2 are shown. It can be seen that the output voltage stabilizes at 400V within 0.1s, achieving both stable power conversion and gain adjustment via PID control.

[0074] According to the expression for duty cycle D, when the input voltage U in =75V, duty cycle D=0.684, output voltage U out =400V, at this time U c =173V, U d =253V; when the input voltage U in =240V, duty cycle D=0.25, output voltage U out =400V, at this time U c=80V, U d =320V. Therefore, the duty cycle adjustment range for simulation and experiment is 0.25-0.684.

[0075] Figure 4 This is a control flowchart of the interleaved DC-DC bidirectional power converter in Embodiment 1 of this utility model.

[0076] like Figure 4 As shown, the MCU first performs power-on and software initialization, which includes setting various registers, configuring interrupts, and initializing peripherals to ensure the converter is in a known and stable state. After initialization, the converter will detect the input voltage U. in Is it greater than or equal to 50V to ensure sufficient power supply for normal operation? If U in If the voltage is greater than or equal to 50V, the system enters soft-start mode. In this mode, the system gradually increases the duty cycle of the PWM signal to avoid current surges and voltage transients during startup, helping to protect circuit components and improve system stability. After soft-start, the system checks the input voltage U again. in The voltage must be greater than or equal to 75V. This is to ensure that the input voltage meets the minimum requirements for the converter to work normally. Once the condition is met, it will enter the normal working mode.

[0077] In normal operating mode, the converter enters the voltage closed-loop control stage, monitoring the output voltage U in real time. out And compare it with the set target value, and adjust the duty cycle of the PWM signal according to the difference, when the output voltage U out When the voltage is less than or equal to 400V, the duty cycle is decreased; conversely, when it is higher, the duty cycle is increased. The control module controls the switching of the transistors to achieve precise regulation of the output voltage. Furthermore, the converter continuously monitors the input voltage U. in When the input voltage is less than or equal to 3V or greater than or equal to 250V, it will enter the soft shutdown mode. At this time, the converter will gradually reduce the duty cycle to make the output voltage drop smoothly, so as to prevent abnormal voltage from damaging the circuit.

[0078] Example 2

[0079] Figure 5 This is a circuit diagram of a DC-DC bidirectional power converter with a single output capacitor connected in series in Embodiment 2 of this utility model.

[0080] like Figure 5 As shown, the single-output interleaved DC-DC bidirectional power converter of this embodiment also includes at least one third sub-circuit, which is connected in series between the voltage input terminal Vin and the voltage output terminal Vout; the third sub-circuit includes: a fourth capacitor C1(m-1), a fifth capacitor C1m, a third inductor L1m, a fifth switch S(2m-2) and a sixth switch S(2m-1).

[0081] The negative terminal of the fourth capacitor C1(m-1) is connected to the positive terminal of the voltage input terminal Vin, and is used to boost the voltage.

[0082] The negative terminal of the fifth capacitor C1m is connected to the positive terminal of the fourth capacitor C1(m-1), and the positive terminal is connected to the voltage output terminal Vout to boost the voltage.

[0083] The first terminal of the third inductor L1m is connected to the positive terminal of the fourth capacitor C1(m-1) and is used to store and release electrical energy.

[0084] The negative terminal of the fifth switch S(2m-2) is connected to the negative terminal of the fourth capacitor C1(m-1), and the positive terminal is connected to the second terminal of the third inductor L1m, which is used to control the circuit to turn on and off according to the signal.

[0085] The negative terminal of the sixth switch S(2m-1) is connected to the second terminal of the third inductor L1m, and the positive terminal is connected to the positive terminal of the fifth capacitor C1m and the positive terminal of the voltage output Vout, respectively, to control the circuit on and off according to the signal.

[0086] The DC-DC bidirectional power converter, which includes a third sub-circuit, uses multiple capacitors connected in series to achieve high voltage output. The number of third sub-circuits connected in series between the voltage input terminal Vin and the voltage output terminal Vout is set according to the required output voltage.

[0087] Example 3

[0088] Figure 6 This is a circuit diagram of the multi-output capacitor-free series-connected DC-DC bidirectional power converter in Embodiment 3 of this utility model.

[0089] like Figure 6 As shown, the multi-output interleaved DC-DC bidirectional power converter in this embodiment also includes at least one fourth sub-circuit, which is connected in series between the voltage input terminal Vin and the voltage output terminal Vout.

[0090] The fourth sub-circuit includes: the sixth capacitor C1i, the fourth inductor L1i, and the seventh switch S1i.

[0091] The sixth capacitor, C1i, has its negative terminal connected to the positive terminal of the voltage input, Vin, and is used to boost the voltage.

[0092] The first terminal of the fourth inductor L1i is connected to the negative terminal of the sixth capacitor C1i, and is used to store and release electrical energy.

[0093] The negative terminal of the seventh switch S1i is connected to the second terminal of the fourth inductor, and its positive terminal is connected to the positive terminal of the sixth capacitor C1i and the positive terminal of the voltage output Vout, respectively, to control the circuit's on / off state according to the signal. In this embodiment, the DC-DC bidirectional power converter with interleaved outputs adopts a distributed design, and the number of fourth sub-circuits is set according to the number of voltage output terminals. It achieves multiple output ports, supports single-stage or multi-stage Buck-Boost circuit configurations, and can adapt to both single-supply operation mode and multi-supply series operation, making it suitable for systems requiring multiple voltage levels.

[0094] Example 4

[0095] Figure 7 This is a circuit diagram of the DC-DC bidirectional power converter with multiple output capacitors connected in series in Embodiment 4 of this utility model.

[0096] like Figure 7 As shown, in this embodiment, a third sub-circuit and a fourth sub-circuit are connected in series between the voltage input terminal Vin and the voltage output terminal Vout of the DC-DC bidirectional power converter with multiple output capacitors in series. The number of the third sub-circuit is set according to the required output voltage of the voltage output terminal, and the number of the fourth sub-circuit is set according to the number of voltage output terminals.

[0097] This embodiment combines the advantages of the architectures in Embodiments 2 and 3, supports asymmetric series-parallel configurations, maintains high-voltage output by connecting multiple capacitors in series, retains multi-output capability through circuit reconfiguration, and can also flexibly connect to various isolated or non-isolated converters, exhibiting high scalability.

[0098] Example 5

[0099] Figure 8 This is a circuit diagram of the DC-DC bidirectional power converter reconstructed by a multi-output capacitor series switch in Embodiment 5 of this utility model.

[0100] Figure 9 This is a circuit diagram of the DC-DC converter cascaded half-bridge LLC resonant converter in Embodiment 5 of this utility model.

[0101] Figure 10 This is a circuit diagram of the multi-port LLC resonant converter with switch multiplexing in Embodiment 5 of this utility model.

[0102] Figure 11 This is a symmetrically adjustable multi-port LLC resonant converter with switch multiplexing in Embodiment 5 of this utility model.

[0103] like Figure 8 , Figure 9 , Figure 10 and Figure 11 As shown, Figure 8The multi-output capacitor series switch reconfiguration DC-DC bidirectional power converter is in Figure 7 Based on the existing structure, the topology can be reconfigured through split or multiplexed configuration of switching devices according to specific application scenarios, thereby further reducing costs and increasing power density.

[0104] In this embodiment, based on Figure 7 Taking the connection of a half-bridge LLC isolated resonant converter at a critical node as an example, the following can be obtained: Figure 9 The DC-DC converter shown is cascaded with a half-bridge LLC resonant converter. However, this structure has a large number of components and redundancy between topologies. Combining and multiplexing the switching devices yields... Figure 10 The switch-multiplexed multi-port LLC resonant converter shown is used as an example in a new energy system application scenario with photovoltaic and energy storage ports. This topology can meet the requirements of multi-port energy management and electrical isolation. This switch-multiplexed multi-port LLC resonant converter mainly consists of two parts. The first part is an interleaved DC-DC bidirectional power converter, composed of three sub-circuits. In this embodiment, these are three Buck-Boost sub-circuits. The first Buck-Boost sub-circuit consists of battery pack 1, photovoltaic 1, first inductor L1, first switch S1, and second switch S2; the second Buck-Boost sub-circuit consists of battery pack 2, photovoltaic 1, second inductor L2, second switch S2, and third switch S3; and the third Buck-Boost sub-circuit consists of battery pack 2, photovoltaic 2, third inductor L3, third switch S3, and fourth switch S4. The second part is a half-bridge LLC resonant converter, whose resonant cavity consists of a magnetizing inductor L... M Resonant inductor L r With resonant capacitor C r The secondary side adopts a full-bridge rectifier structure, and the rectifier diode is denoted as D. s1 D s2 D s3 D s4 When the first switch S1 and the fourth switch S4 are both turned on, a power path is provided for the forward resonance of the LLC converter. When the second switch S2 and the third switch S3 are turned on, the reverse resonance of the LLC converter is achieved. Structural optimization is achieved through the multiplexing of switching devices: on the one hand, the multiplexing of switches between the three Buck-Boost sub-circuits is realized; on the other hand, the multiplexing of switches between the Buck-Boost and LLC bridge arms is completed.

[0105] exist Figure 10Timing constraints require that the voltage relationship of the series-connected input ports be controlled by adjusting the duty cycle of the LLC converter. This control strategy results in an asymmetric waveform for the LLC resonant cavity. To compensate for the asymmetry of the LLC operation, the symmetric operating mode of the LLC converter can be reconstructed by splitting the key power devices and implementing a timing-coordinated control design. Based on this split-switch optimization strategy, the following is obtained: Figure 11 The switch-multiplexed, symmetrically adjustable multi-port LLC resonant converter shown still contains two identical Buck-Boost sub-circuits. Unlike the previous converter, the three multiplexed power devices are split into four, thus gaining more possibilities in timing design. Therefore, the first Buck-Boost sub-module in the first part consists of photovoltaic array 1, battery, first inductor L1, first switch S1, second switch S2, third switch S3, and fourth switch S4. The second Buck-Boost sub-module consists of photovoltaic array 2, battery, second inductor L2, fourth switch S4, first switch S1, second switch S2, and third switch S3. When first switch S1 and fourth switch S4 are simultaneously turned on, they provide a power path for the forward resonance of the LLC converter. When second switch S2 and third switch S3 are simultaneously turned on, the reverse resonance of the LLC converter is achieved. Through timing design, the duty cycle of the LLC can be adjusted simultaneously with the duty cycle of the Buck-Boost converter, thus achieving symmetrically adjustable LLC converter.

[0106] Regarding the above embodiments Figure 10 Simulation tests were performed on a multi-port asymmetric LLC resonant converter with switch multiplexing, and its parameters are shown in Table 2 below:

[0107] Table 2 shows the main parameters of the prototype.

[0108]

[0109]

[0110] Figure 12 This is a waveform diagram of the photovoltaic 70V input of the multi-port asymmetric LLC resonant converter with switch multiplexing in Embodiment 5 of this utility model.

[0111] Figure 13 This is a waveform diagram of the photovoltaic 130V input of the multi-port asymmetric LLC resonant converter with switch multiplexing in Embodiment 5 of this utility model.

[0112] The simulation results are as follows, with simulation tests conducted for input voltages of 70V and 130V respectively. Figure 12 The waveform diagram is shown when the photovoltaic voltage is 70V input. Figure 13The waveform diagram shows that the photovoltaic input voltage is 130V. It can be seen that the preamplifier stage regulates the photovoltaic port voltage by adjusting the duty cycle D of the LLC; the post-amplifier stage regulates the voltage by adjusting the frequency f. s The adjustment ensures the stability of the output voltage. The waveforms from top to bottom represent the linear inductor current i corresponding to the two Buck-Boost sub-circuits. L1 i L2 Resonant current ir, resonant voltage across resonant capacitor Cr The drain-source voltage v of the second switch S2 ds2 .

[0113] against Figure 11 A multi-port LLC resonant converter with adjustable symmetry and switch multiplexing was simulated and tested. Its parameters are shown in Table 3 below.

[0114] Table 3 shows the main parameters of the prototype.

[0115]

[0116] Figure 14 This is a waveform diagram of the photovoltaic 90V input of the symmetrically adjustable multi-port LLC resonant converter with switch multiplexing in Embodiment 5 of this utility model.

[0117] Figure 15 This is a waveform diagram of the photovoltaic 45V input of the symmetrically adjustable multi-port LLC resonant converter with switch multiplexing in Embodiment 5 of this utility model.

[0118] like Figure 14 and Figure 15 As shown, the simulation results are as follows. Simulation tests were conducted for input voltages of 54V and 90V respectively. It can be seen that it can be adjusted by both frequency and duty cycle, achieving both the traditional photovoltaic MPPT (Maximum power point tracking) and gain adjustment through frequency conversion. Furthermore, due to the split configuration of the switching devices, compared to... Figure 10 The structure allows for adjustment of the LLC resonant time symmetry by regulating the duty cycle of the split switching device.

[0119] The role and effect of the embodiments

[0120] The interleaved DC-DC bidirectional power converter according to this embodiment includes: a first capacitor for boosting voltage; a second capacitor, with its positive terminal connected to the negative terminal of the first capacitor, for boosting voltage; a third capacitor, with its positive terminal connected to the negative terminal of the second capacitor, for input voltage; a voltage input terminal, with its positive terminal connected to the positive terminal of the second capacitor and its negative terminal connected to the negative terminal of the second capacitor; a first inductor, with its first terminal connected to the positive terminal of the second capacitor, for storing and releasing electrical energy; a second inductor, with its first terminal connected to the negative terminal of the second capacitor, for storing and releasing electrical energy; a first switch, with its negative terminal connected to the second terminal of the first inductor and its positive terminal connected to the positive terminal of the first capacitor, for controlling the circuit to turn on and off according to a signal; and a second switch, with its positive terminal connected to the positive terminal of the second capacitor and its negative terminal connected to the negative terminal of the second capacitor, for controlling the circuit to turn on and off according to a signal. The circuit consists of two sub-circuits: a first inductor, a second switch, and a third capacitor. The first inductor, the first switch, the second switch, and the first capacitor form the first sub-circuit, while the second inductor, the third switch, the fourth switch, and the second capacitor form the second sub-circuit. Therefore, this interleaved DC-DC bidirectional power converter achieves efficient DC-DC voltage conversion by interleaving and controlling the switching of the two sub-circuits, effectively reducing energy loss and maintaining stable output voltage.

[0121] The DC-DC bidirectional power converter with a single output capacitor in series in Example 2 uses multiple capacitors in series to achieve high voltage output.

[0122] The multi-output capacitor-free series-connected DC-DC bidirectional power converter in Example 3 adopts a distributed design to realize multiple output ports.

[0123] The DC-DC bidirectional power converter with multiple output capacitors in series in Example 4 combines the advantages of Example 2 and Example 3. While maintaining high voltage output by multiple capacitors in series, it retains the multi-output capability through circuit reconfiguration.

[0124] The multi-port asymmetric LLC resonant converter design in Example 5 significantly reduces the number of components and system cost while increasing power density.

[0125] The design of the symmetrically adjustable multi-port LLC resonant converter with switch multiplexing in Example 5 can achieve the symmetrical adjustable LLC converter by changing the Buck-Boost duty cycle while also adjusting the LLC duty cycle.

[0126] Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A DC-DC bidirectional power converter with interleaved superposition, characterized in that, include: The first capacitor is used to boost the voltage; The positive terminal of the second capacitor is connected to the negative terminal of the first capacitor, and it is used to boost the voltage. The positive terminal of the third capacitor is connected to the negative terminal of the second capacitor, and it is used to boost the voltage. The voltage input terminal has its positive terminal connected to the positive terminal of the second capacitor and its negative terminal connected to the negative terminal of the second capacitor, and is used for input voltage. The first inductor has its first terminal connected to the positive terminal of the second capacitor, and is used to store and release electrical energy. The second inductor, with its first end connected to the negative terminal of the second capacitor, is used to store and release electrical energy. The first switching transistor has its negative terminal connected to the second terminal of the first inductor and its positive terminal connected to the positive terminal of the first capacitor, and is used to control the circuit to turn on and off according to the signal. The second switching transistor has its positive terminal connected to the positive terminal of the second capacitor and its negative terminal connected to the negative terminal of the second capacitor, and is used to control the circuit to turn on and off according to the signal. The third switching transistor has its positive terminal connected to the positive terminal of the second capacitor and its negative terminal connected to the second terminal of the second inductor, and is used to control the circuit to turn on and off according to the signal. The fourth switching transistor has its positive terminal connected to the second terminal of the second capacitor and its negative terminal connected to the negative terminal of the third capacitor, and is used to control the circuit to turn on and off according to the signal. The voltage output terminal has its positive terminal connected to the positive terminal of the first switching transistor and its negative terminal connected to the negative terminal of the fourth switching transistor, and is used to output voltage. The first inductor, the first switch, the second switch, and the first capacitor constitute the first sub-circuit, and the second inductor, the third switch, the fourth switch, and the second capacitor constitute the second sub-circuit.

2. The interleaved DC-DC bidirectional power converter according to claim 1, characterized in that, Also includes: The first filter capacitor has its positive terminal connected to the positive terminal of the voltage input terminal and its negative terminal connected to the negative terminal of the voltage input terminal, and is used to filter out high-frequency noise and ripple in the input voltage. The second filter capacitor has its positive terminal connected to the positive terminal of the voltage output terminal and its negative terminal connected to the negative terminal of the voltage output terminal. It is used to filter out high-frequency noise and ripple in the output voltage.

3. The interleaved DC-DC bidirectional power converter according to claim 1, characterized in that, Also includes: The control module generates PWM signals based on the input voltage, output voltage, input current, and output current signals provided by feedback sampling to control the first switch, the second switch, the third switch, and the fourth switch.

4. The interleaved DC-DC bidirectional power converter according to claim 3, characterized in that: in, When the first and fourth switching transistors are turned on and the second and third switching transistors are turned off, the first inductor releases electrical energy to the voltage output terminal, and the second inductor stores electrical energy from the voltage input terminal.

5. The interleaved DC-DC bidirectional power converter according to claim 3, characterized in that: in, When the second and third switches are turned on and the first and fourth switches are turned off, the second inductor releases electrical energy to the voltage output terminal, and the first inductor stores electrical energy from the voltage input terminal.

6. The interleaved DC-DC bidirectional power converter according to claim 1, characterized in that, It also includes at least one third sub-circuit connected in series between the voltage input terminal and the voltage output terminal; The third sub-circuit includes: The fourth capacitor has its negative terminal connected to the positive terminal of the voltage input terminal, and is used to boost the voltage. The fifth capacitor has its negative terminal connected to the positive terminal of the fourth capacitor, and its positive terminal connected to the voltage output terminal, which is used to boost the voltage. The third inductor, with its first end connected to the positive terminal of the fourth capacitor, is used to store and release electrical energy. The fifth switching transistor has its negative terminal connected to the negative terminal of the fourth capacitor and its positive terminal connected to the second terminal of the third inductor, and is used to control the circuit to turn on and off according to the signal. The sixth switch has its negative terminal connected to the second terminal of the third inductor, and its positive terminal connected to the positive terminal of the fifth capacitor and the positive terminal of the voltage output terminal, respectively, and is used to control the circuit to turn on and off according to the signal.

7. The interleaved DC-DC bidirectional power converter according to claim 6, characterized in that, It also includes at least one fourth sub-circuit connected in series between the voltage input terminal and the voltage output terminal; The fourth sub-circuit includes: The sixth capacitor has its negative terminal connected to the positive terminal of the voltage input terminal, and is used to boost the voltage. The fourth inductor, with its first terminal connected to the negative terminal of the sixth capacitor, is used to store and release electrical energy. The seventh switch has its negative terminal connected to the second terminal of the fourth inductor, and its positive terminal connected to the positive terminal of the sixth capacitor and the positive terminal of the voltage output terminal, respectively, and is used to control the circuit to turn on and off according to the signal.

8. The interleaved DC-DC bidirectional power converter according to claim 7, characterized in that: in, The voltage input terminal and the voltage output terminal are connected in series with the third sub-circuit and the fourth sub-circuit. The number of the third sub-circuit is set according to the required output voltage of the voltage output terminal, and the number of the fourth sub-circuit is set according to the number of voltage output terminals.

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