Multi-output resonant buck converter and implementation method

Abstract

The invention discloses a multi-output resonant buck converter and an implementation method. The multi-output resonant buck converter is composed of a full-control switching device and a plurality of modular combination topologies. Each combined topology is integrated with a diode rectification circuit and a parameter-differentiated resonant network, and multi-path independent voltage output is realized through a common switching device. The control strategy adopts the same switching frequency and complementary duty ratio method to realize the full-range adjustment of the output voltage, and by combining the parameter optimization design of each resonant circuit, the switching loss and electromagnetic interference are effectively reduced while the soft switching characteristic is maintained. The modular design not only improves the power density and the system reliability, but also simplifies the cooperative control logic of the system. The multi-output resonant buck converter and the implementation method can be widely applied to the fields of electric vehicle high-voltage systems, smart grids and multi-voltage power supply equipment, and have remarkable cost benefits and engineering practical values.

Description

Technical Field

[0001] The present invention relates to the field of power electronics, and particularly to a multi-output resonant step-down converter and an implementation method thereof. Background Art

[0002] With the rapid development of new energy power generation, electric vehicles, smart grids and other fields, the demand for DC power supply with multiple voltage levels is increasing day by day. For example, in an electric vehicle charging system, it is necessary to provide DC outputs with different voltage levels for a high-voltage power battery, low-voltage vehicle-mounted equipment and an auxiliary power supply at the same time. The traditional solution usually adopts multiple independent DC-DC converters connected in parallel to achieve multi-voltage output. However, this method has high system complexity and cost. Multiple sets of independent converters need to be equipped with their own switching devices, magnetic components and control circuits, resulting in a large system volume and increased cost, and the cooperative control between multiple modules is difficult.

[0003] To simplify the structure, the prior art has proposed an integrated multi-output converter based on a multi-winding transformer or a multi-resonant branch. However, within a wide voltage output range, it is difficult for the resonant components to maintain zero-voltage switching or zero-current switching in the full load range, resulting in increased switching losses. Moreover, to achieve independent regulation of multiple voltages, it is necessary to adopt differential duty cycle or frequency control for each branch, resulting in a complex control algorithm. Summary of the Invention

[0004] Aiming at the defects of the prior art, the purpose of the present invention is to provide a multi-output resonant step-down converter and an implementation method thereof, which can realize the efficient independent output of multiple voltage levels through the optimization of the resonant network parameters under the conditions of sharing switching devices and unified control parameters, while maintaining the soft-switching characteristics of the converter, so as to simplify the system design, improve the system power density and reliability.

[0005] To achieve the above object, the present invention provides a multi-output resonant step-down converter, including a main power circuit, the main power circuit includes N combined topologies A and two fully controlled switching devices, N is a positive integer, wherein:

[0006] The first terminal p of the fully controlled switching device S1 is connected to the positive pole of the input voltage V in The second terminal n of the fully controlled switching device S1 is connected to the first terminal p of the fully controlled switching device S2 and the first terminal a of the N combined topologies A, and the second terminal n of the fully controlled switching device S2 is connected to the negative pole of the input voltage and the second terminal b of the N combined topologies A;

[0007] The combined topology A includes a diode rectifier circuit and a resonant circuit, and the resonant circuit is composed of a resonant inductor L r and a resonant capacitor C r constituting, the resonant inductor Lr The first terminal p of it is connected to the first terminal a of the N combined topologies A, and the resonant inductor L r The second terminal n of it is connected to the first terminal p of the resonant capacitor C r The diode rectifier circuit includes two diodes D1, D2, a filter capacitor C o and a load R L The anode of the diode D1 is connected to the cathode of the diode D2 and the second terminal n of the resonant capacitor C r The cathode of the diode D1 is connected to the first terminal p of the filter capacitor C o The first terminal p of the load R L The anode of the diode D2 is connected to the second terminal b of the N combined topologies A, the second terminal n of the filter capacitor C o The second terminal n of the load R L is connected;

[0008] The first terminal p of the resonant inductor L r of each of the combined topologies A is connected to the first terminal p of the resonant inductor L r of the next combined topology A and the first terminal a of the N combined topologies A. The anode of the diode D2 of each of the combined topologies A is connected to the anode of the diode D2 of the next combined topology A and the second terminal b of the N combined topologies A.

[0009] To achieve the above object, the present invention provides a method for implementing a multi-output resonant step-down converter. The full-controlled switching devices S1 and S2 have the same switching frequency and complementary duty cycles. By respectively adjusting the values of the resonant inductor and the resonant capacitor in the resonant circuit of each of the combined topologies A, different voltage levels are output. Each of the combined topologies A satisfies 4π 2 L r C r f s 2 > 1.

[0010] The advantages and positive effects of a multi-output resonant buck converter and its implementation method of the present invention are as follows: By using a shared switching device and unified control parameters, the number of switching devices, magnetic components, and control circuits is significantly reduced, effectively shrinking the system volume and reducing the hardware cost. At the same time, the multi-module collaborative control logic is simplified. Each combined topology generates full-range outputs of different voltage levels under unified control by differentially configuring the parameters of the resonant inductor and resonant capacitor, avoiding the dependence on traditional multi-winding transformers or complex controls, and improving the overall efficiency of the system while maintaining the soft-switching characteristics of the system. Moreover, a standardized module structure is adopted, and the number of output paths can be flexibly expanded by increasing or decreasing the number of modules, facilitating adaptation to different application scenarios and simplifying the maintenance and upgrade processes.

[0011] The present invention will be described below with reference to the accompanying drawings. Description of the Drawings

[0012] Figure 1 is the circuit diagram of combined topology A in a multi-output resonant buck converter and its implementation method provided by the present invention;

[0013] Figure 2 is the circuit topology structure diagram of the embodiment in a multi-output resonant buck converter and its implementation method provided by the present invention. Detailed Embodiments

[0014] In order to make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not limited to the present invention.

[0015] Referring to Figure 1 、 Figure 2 , in an embodiment of a multi-output resonant buck converter and its implementation method of the present invention, it includes a main power circuit. The main power circuit includes N combined topologies A and two fully controlled switching devices, where N is a positive integer. Among them:

[0016] The first terminal p of the fully controlled switching device S1 is connected to the positive pole of the input voltage V in The second terminal n of the fully controlled switching device S1 is connected to the first terminal p of the fully controlled switching device S2 and the first terminal a of N combined topologies A. The second terminal n of the fully controlled switching device S2 is connected to the negative pole of the input voltage and the second terminal b of N combined topologies A;

[0017] The combined topology A includes a diode rectifier circuit and a resonant circuit. The resonant circuit consists of a resonant inductor L r and a resonant capacitor C r The resonant inductor L rThe first terminal p of it is connected to the first terminal a of N combined topologies A, and the resonant inductor L r The second terminal n of it is connected to the resonant capacitor C r The first terminal p of it is connected. The diode rectifier circuit includes two diodes D1, D2, a filter capacitor C o And a load R L , the anode of diode D1 is connected to the cathode of diode D2 and the second terminal n of the resonant capacitor C r The cathode of diode D1 is connected to the first terminal p of the filter capacitor C o The first terminal p of it, the first terminal p of the load R L The anode of diode D2 is connected to the second terminal b of N combined topologies A, the second terminal n of the filter capacitor C o The second terminal n of it, the second terminal n of the load R L are connected;

[0018] The first terminal p of the resonant inductor L of each combined topology A r is connected to the first terminal p of the resonant inductor L of the next combined topology A, the first terminal a of N combined topologies A. The anode of the diode D2 of each combined topology A is connected to the anode of the diode D2 of the next combined topology A and the second terminal b of N combined topologies A. r are connected.

[0019] To implement the control of the multi-output resonant buck converter provided by the present invention, the full-control switch device S1 and the full-control switch device S2 have the same switching frequency and complementary duty cycles. By respectively adjusting the resonant inductor and resonant capacitor values of the resonant circuits in each of the combined topologies A, different voltage levels are output. Moreover, in order to achieve the full-range operation of the output voltage of each combined topology A, each combined topology A satisfies 4π 2 L r C r f s 2 > 1.

[0020] The advantages and positive effects of a multi-output resonant buck converter and its implementation method of the present invention are as follows: By using shared switch devices and unified control parameters, the number of switch devices, magnetic components, and control circuits is significantly reduced, effectively reducing the system volume and hardware cost. At the same time, the multi-module cooperative control logic is simplified. Each combined topology generates full-range outputs of different voltage levels under unified control by differentiating the configuration of the resonant inductor and resonant capacitor parameters, avoiding the dependence on traditional multi-winding transformers or complex controls, and improving the overall system efficiency while maintaining the soft-switching characteristics of the system. Moreover, by adopting a standardized module structure, the number of output channels can be flexibly expanded by increasing or decreasing the number of modules, facilitating adaptation to different application scenarios, and simplifying the maintenance and upgrade processes.

[0021] The embodiments described above are only descriptions of the preferred embodiments of the present invention, and do not limit the concept and scope of the present invention. Without departing from the premise of the design scheme of the present invention, various modifications and improvements made by those skilled in the art to the technical solution of the present invention should all fall within the protection scope of the present invention. The technical content claimed by the present invention has been fully recorded in the claims.

Claims

1. A multi-output resonant buck converter, characterized in that, It includes a main power circuit, and the main power circuit includes N combined topologies A and two fully-controlled switching devices, where N is a positive integer, and: The first terminal p of the fully controlled switch device S1 is connected to the positive pole of the input voltage V in The second terminal n of the fully controlled switch device S1 is connected to the first terminal p of the fully controlled switch device S2 and the first terminal a of the N combined topologies A. The second terminal n of the fully controlled switch device S2 is connected to the negative pole of the input voltage and the second terminal b of the N combined topologies A; The combined topology A includes a diode rectifier circuit and a resonant circuit, and the resonant circuit consists of a resonant inductor L r and a resonant capacitor C r . The first terminal p of the resonant inductor L r is connected to the first terminal a of the N combined topologies A. The second terminal n of the resonant inductor L r is connected to the first terminal p of the resonant capacitor C r . The diode rectifier circuit includes two diodes D1, D2, a filter capacitor C o and a load R L . The anode of the diode D1 is connected to the cathode of the diode D2 and the second terminal n of the resonant capacitor C r . The cathode of the diode D1 is connected to the first terminal p of the filter capacitor C o and the first terminal p of the load R L . The anode of the diode D2 is connected to the second terminal b of the N combined topologies A, the second terminal n of the filter capacitor C o and the second terminal n of the load R L . The resonant inductor L of each of the combined topologies A r The first terminal p of is connected to the first terminal p of the resonant inductor L of the next combined topology A r The first terminal a of the N combined topologies A. The anodes of the diodes D2 of each of the combined topologies A are connected to the anodes of the diodes D2 of the next combined topology A and the second terminal b of the N combined topologies A.

2. The implementation method of a multi-output resonant buck converter according to claim 1, wherein The fully-controlled switching device S1 and the fully-controlled switching device S2 have the same switching frequency and complementary duty cycles, and different voltage levels are output by respectively adjusting the resonance inductance and resonance capacitance values of the resonance circuits in each of the combined topologies A.

3. A method for implementing a multi-output resonant buck converter as described in claim 2, characterized in that, Each of the combined topologies A satisfies 4π 2 L r C r f s 2 > 1.

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