Double-BUCK three-port bidirectional conversion circuit based on magnetic coupling and device thereof

Abstract

The utility model relates to a double-BUCK three-port bidirectional conversion circuit based on magnetic coupling and a device thereof, comprising a first bridge circuit, a second bridge circuit, a transformation circuit and an isolation current conversion network circuit, the transformation circuit comprises a double-channel magnetic coupling inductor comprising a first coil, a second coil, a common magnetic core and a non-common magnetic core, the first coil and the second coil are in magnetic circuit coupling and act on different branches of the voltage transformation circuit respectively, so that the voltage transformation circuit forms a staggered parallel double-BUCK circuit, external ports of the conversion circuit are DC ports and are used for being connected with a power supply or a load, and the controller controls the conversion circuit to output target voltage and current. According to the utility model, the first coil and the second coil share part of the magnetic core and form magnetic circuit coupling, so that the volume is effectively reduced, the magnetic material loss is reduced, and the cost is reduced; according to the utility model, a double-channel magnetic coupling inductor is provided to form a staggered parallel double-BUCK circuit, the electric energy conversion efficiency is effectively improved, and current ripples are reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to power electronics technical field more specifically, relate to a kind of based on magnetic coupling double BUCK three-port bidirectional conversion circuit and its device. BACKGROUND

[0002] In order to respond to the needs of current energy saving and emission reduction and control air pollution, new energy energy storage system, new energy engineering vehicle and electric vehicle are greatly promoted and used in market;Compared with the prior art, the single-channel BUCK circuit used in the direct-current output port has the defects of low conversion efficiency, large output current ripple and large component loss.

[0003] Therefore, it is urgent to develop a kind of based on magnetic coupling double BUCK three-port bidirectional conversion circuit to improve the problem of low component conversion efficiency, large output current ripple and large component loss of third direct-current port. UTILITY MODEL CONTENT

[0004] The technical problem to be solved by the utility model is the low component conversion efficiency, large output current ripple and large component loss of direct-current output port, and a kind of based on magnetic coupling double BUCK three-port bidirectional conversion circuit and its device are provided to solve the above defects of the prior art.

[0005] The technical scheme adopted by the utility model to solve its technical problems is:

[0006] A kind of based on magnetic coupling double BUCK three-port bidirectional conversion circuit is constructed, including first bridge circuit, second bridge circuit, transformer circuit and isolation current conversion network circuit, the first bridge circuit, the second bridge circuit and the transformer circuit are connected with the isolation current conversion network circuit respectively, and the isolation current conversion network circuit is used to provide electrical isolation;

[0007] The transformer circuit includes double-channel magnetic coupling inductance, the double-channel magnetic coupling inductance includes first coil and second coil, and the first coil and the second coil are magnetically coupled;The first coil and the second coil are respectively applied to different branches of the transformer circuit, so that the transformer circuit forms two BUCK circuits in staggered parallel.

[0008] Further, the external port of the first bridge circuit, the second bridge circuit and the transformer circuit is direct-current port, and is used to connect power supply or load.

[0009] Further, the voltage conversion circuit further comprises a ninth switch, a tenth switch, an eleventh switch, a twelfth switch and a fourth capacitor, the ninth switch, the twelfth switch and the first coil of the double-channel magnetic coupled inductor form a first BUCK branch, the tenth switch, the eleventh switch and the second coil of the double-channel magnetic coupled inductor form a second BUCK branch, the first BUCK branch and the second BUCK branch are staggered in parallel and share the fourth capacitor; the on-off time of the ninth switch and the twelfth switch are opposite, the on-off time of the tenth switch and the eleventh switch are opposite, and the ninth switch and the tenth switch form an angle phase difference of 0 to 180 degrees.

[0010] Further, the first bridge circuit comprises a first switch, a second switch, a third switch and a fourth switch, the first switch and the third switch form a first bridge arm, the second switch and the fourth switch form a second bridge arm, the first bridge arm and the second bridge arm are parallel to each other, the on-off time of the first switch and the third switch are opposite, the on-off time of the second switch and the fourth switch are opposite.

[0011] Further, the second bridge circuit comprises a fifth switch, a sixth switch, a seventh switch, an eighth switch and a third capacitor, the fifth switch and the seventh switch form a third bridge arm, the sixth switch and the eighth switch form a fourth bridge arm, the third bridge arm, the fourth bridge arm and the third capacitor are parallel to each other, the on-off time of the fifth switch and the seventh switch are opposite, the on-off time of the sixth switch and the eighth switch are opposite.

[0012] Further, the isolation current conversion network circuit comprises a first capacitor, a first inductor, a second capacitor and a three-winding transformer, the transformer comprises a first winding, a second winding and a third winding, the first capacitor, the first inductor and the first winding are connected in series, the second capacitor and the second winding are connected in series, and the third winding is connected to the ninth switch and the tenth switch respectively; in the isolation current conversion network circuit, the first inductor and the three-winding transformer comprise the same magnetic core or different magnetic cores respectively.

[0013] The utility model also provides a device based on magnetic coupling double BUCK three port two -way conversion circuit, including first bridge type module, second bridge type module, voltage transformation module, isolation current conversion module and controller, isolation current conversion module is used for connecting first bridge type module second bridge type module with voltage transformation module to form electrical isolation, the external port of first bridge type module second bridge type module with voltage transformation module is all direct current port, the external port is used for connecting power or load, the controller includes acquisition module, analysis module and control module, analysis module is connected with acquisition module and control module electricity respectively, the controller controls the on-off of each switch in first bridge type module second bridge type module with voltage transformation module to control the size of voltage and current of change circuit output.

[0014] Further, the voltage transformation module includes a double-channel magnetic coupling inductor, the double-channel magnetic coupling inductor includes a non-shared magnetic core, a coil and a shared magnetic core, the coil includes a first coil and a second coil, a reserved space is arranged between the shared magnetic core and the non-shared magnetic core, the first coil and the second coil are located in the reserved space, and the shared magnetic core is located between the first coil and the second coil, so that the first coil and the second coil are magnetically coupled.

[0015] The utility model has the advantages that:

[0016] The utility model relates to a kind of based on magnetic coupling double BUCK three port two -way conversion circuit and its device, first bridge circuit, second bridge circuit, voltage transformation circuit, isolation current conversion network circuit and controller, voltage transformation circuit includes the double-channel magnetic coupling inductor including first coil, second coil, shared magnetic core and non-shared magnetic core, first coil and second coil magnetic coupling, and different branch of voltage transformation circuit is acted on respectively, to make voltage transformation circuit form interlaced parallel double BUCK circuit, the external port of conversion circuit is all direct current port, and for connecting power or load, controller controls conversion circuit, to output target voltage and current.The utility model proposes that first coil and second coil share part of magnetic core, and form magnetic coupling, effectively reduce volume, reduce magnetic material loss, reduce cost;The utility model proposes that double-channel magnetic coupling inductor forms interlaced parallel double BUCK circuit, effectively improve electric energy conversion efficiency, reduce current ripples. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is a circuit diagram of a kind of based on magnetic coupling double BUCK three port two -way conversion circuit in an embodiment of the utility model;

[0018] Figure 2 It is a control circuit diagram of a kind of based on magnetic coupling double BUCK three port two -way conversion circuit in an embodiment of the utility model.

[0019] Figure 3 is a control timing diagram of the controller to each control switch in an embodiment of the utility model;

[0020] Figure 4 is the voltage simulation waveform diagram of three winding transformer when the current flows into the first direct current port and flows out from the second direct current port Vdc2 and the third direct current port respectively in an embodiment of the utility model;

[0021] Figure 5 is the current simulation waveform diagram of the first inductance and double channel magnetic coupling inductance when the current flows into the first direct current port and flows out from the second direct current port Vdc2 and the third direct current port respectively in an embodiment of the utility model;

[0022] Figure 6 is the current simulation waveform diagram of the first direct current port, the second direct current port Vdc2 and the third direct current port when the current flows into the first direct current port and flows out from the second direct current port Vdc2 and the third direct current port respectively in an embodiment of the utility model;

[0023] Figure 7 is the voltage simulation waveform diagram of three winding transformer when the current flows into the second direct current port Vdc2 and flows out from the first direct current port and the third direct current port respectively in an embodiment of the utility model;

[0024] Figure 8 is the current simulation waveform diagram of the first inductance and double channel magnetic coupling inductance when the current flows into the second direct current port Vdc2 and flows out from the first direct current port and the third direct current port respectively in an embodiment of the utility model;

[0025] Figure 9 is the current simulation waveform diagram of the first direct current port, the second direct current port Vdc2 and the third direct current port when the current flows into the second direct current port Vdc2 and flows out from the first direct current port and the third direct current port respectively in an embodiment of the utility model;

[0026] Figure 10 is the voltage simulation waveform diagram of three winding transformer when the current flows into the third direct current port and flows out from the first direct current port and the second direct current port Vdc2 respectively in an embodiment of the utility model;

[0027] Figure 11 is the current simulation waveform diagram of the first inductance and double channel magnetic coupling inductance when the current flows into the third direct current port and flows out from the first direct current port and the second direct current port Vdc2 respectively in an embodiment of the utility model;

[0028] Figure 12is the current simulation waveform diagram of the first DC port, the second DC port Vdc2 and the third DC port when the current flows from the third DC port, and flows out from the first DC port and the second DC port Vdc2 respectively in an embodiment of the utility model;

[0029] Figure 13 is the structure diagram of the device based on the magnetic coupling double BUCK three-port bidirectional conversion circuit in an embodiment of the utility model;

[0030] Figure 14 is the perspective view of the double channel magnetic coupling inductor in an embodiment of the utility model;

[0031] Figure 15 is the explosion view of the double channel magnetic coupling inductor in an embodiment of the utility model;

[0032] Figure 16 is the magnetic simulation diagram of the double channel magnetic coupling inductor in an embodiment of the utility model;

[0033] Figure 17 is the first coil and the second coil current change with time diagram of the double channel magnetic coupling inductor under the target parameter in an embodiment of the utility model;

[0034] Figure 18 is the third DC port current change with time diagram under the target parameter in an embodiment of the utility model.

[0035] Label explanation:

[0036] Q1, first switch;Q2, second switch;Q3, third switch;Q4, fourth switch;L1, first inductor;C1, first capacitor;Q5, fifth switch;Q6, sixth switch;Q7, seventh switch;Q8, eighth switch;C2, second capacitor;C3, third capacitor;L2, double channel magnetic coupling inductor;L2_W1, first coil;L2_W2, second coil;Q9, ninth switch;Q10, tenth switch;Q11, eleventh switch;Q12, twelfth switch;C4, fourth capacitor;T1, three-winding transformer;T1_W1, first winding;T1_W2, second winding;T1_W3, third winding;Vdc1, first DC port;Vdc2, second DC port Vdc2;Vdc3, third DC port;10, first bridge module;20, second bridge module;30, transformation module;40, controller;401, acquisition module;402, analysis module;403, control module;50, isolation current conversion module;1, common magnetic core;2, non-common magnetic core. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application.

[0038] Please refer to the accompanying Figures 1-18 The utility model provides a kind of based on magnetic coupling double BUCK three-port bidirectional conversion circuit, including first bridge circuit, second bridge circuit, transformer circuit and isolated current conversion network circuit, first bridge circuit, second bridge circuit and transformer circuit are connected isolated current conversion network circuit respectively, and isolated current conversion network circuit is used to provide electrical isolation;

[0039] Transformer circuit includes double-channel magnetic coupling inductance L2, double-channel magnetic coupling inductance L2 includes first coil L2_W1 and second coil L2_W2, and first coil L2_W1 and second coil L2_W2 are coupled in magnetic circuit;First coil L2_W1 and second coil L2_W2 are respectively applied to different branch of transformer circuit, to make transformer circuit form two BUCK circuits of staggered parallel.

[0040] In the embodiment, the external ports of the first bridge circuit, the second bridge circuit and the voltage transformation circuit are DC ports, and are used for connecting power supply or load, wherein, any one of the external ports is connected with the power supply, and the other two are connected with the load, forming a three-port bidirectional output circuit. In a specific embodiment, the external ports of the first bridge circuit are connected with the power supply, and the other external ports are connected with the load. The first bridge circuit comprises a first switch Q1, a second switch Q2, a third switch Q3 and a fourth switch Q4. The first switch Q1 and the third switch Q3 form a first bridge arm, and the second switch Q2 and the fourth switch Q4 form a second bridge arm. The first bridge arm and the second bridge arm are connected in parallel with each other. The on-off time of the first switch Q1 and the third switch Q3 is opposite, and the on-off time of the second switch Q2 and the fourth switch Q4 is opposite. The on-off time of the first switch Q1, the second switch Q2, the third switch Q3 and the fourth switch Q4 is controlled, so as to control the voltage and current size and direction flowing into the second bridge circuit and the voltage transformation circuit. The second bridge circuit comprises a fifth switch Q5, a sixth switch Q6, a seventh switch Q7, an eighth switch Q8 and a third capacitor C3. The fifth switch Q5 and the seventh switch Q7 form a third bridge arm, and the sixth switch Q6 and the eighth switch Q8 form a fourth bridge arm. The third bridge arm, the fourth bridge arm and the third capacitor C3 are connected in parallel with each other. The on-off time of the fifth switch Q5 and the seventh switch Q7 is opposite, and the on-off time of the sixth switch Q6 and the eighth switch Q8 is opposite. The on-off time of the fifth switch Q5, the sixth switch Q6, the seventh switch Q7 and the eighth switch Q8 is controlled, so as to control the output voltage and current size and direction of the external port of the second bridge circuit. The voltage transformation circuit comprises a double-channel magnetic coupling inductor L2, a ninth switch Q9, a tenth switch Q10, an eleventh switch Q11, a twelfth switch Q12 and a fourth capacitor C4. The double-channel magnetic coupling inductor L2 comprises a first coil L2_W1, a second coil L2_W2, a shared magnetic core 1 and a non-shared magnetic core 2. The first coil L2_W1 and the second coil L2_W2 form a magnetic circuit coupling through the shared magnetic core 1. The ninth switch Q9, the twelfth switch Q12 and the first coil L2_W1 of the double-channel magnetic coupling inductor L2 form a first BUCK branch. The tenth switch Q10, the eleventh switch Q11 and the second coil L2_W2 of the double-channel magnetic coupling inductor L2 form a second BUCK branch. The first BUCK branch and the second BUCK branch share the fourth capacitor C4, and form two interlaced parallel BUCK branches. The on-off time of the ninth switch Q9 and the twelfth switch Q12 is opposite, and the on-off time of the tenth switch Q10 and the eleventh switch Q11 is opposite. The ninth switch Q9 and the tenth switch Q10 form a phase difference of 0 to 180 degrees. The on-off time of the ninth switch Q9, the tenth switch Q10, the eleventh switch Q11 and the twelfth switch Q12 is controlled, so as to control the output voltage and current size and direction of the external port of the voltage transformation circuit.The first bridge circuit, the second bridge circuit and the voltage transformation circuit are respectively connected with an isolated current conversion network circuit, the isolated current conversion network circuit comprises a first capacitor C1, a first inductor L1, a second capacitor C2 and a three-winding transformer T1, the transformer comprises a first winding T1_W1, a second winding T1_W2 and a third winding T1_W3, the first capacitor C1, the first inductor L1 and the first winding T1_W1 are connected in series and are respectively connected with a first bridge arm and a second bridge arm, the second capacitor C2 and the second winding T1_W2 are connected in series and are respectively connected with a third bridge arm and a fourth bridge arm, and the third winding T1_W3 is respectively connected with a ninth switch Q9 and a tenth switch Q10, the isolated current conversion network circuit is used for providing electrical isolation, in the isolated current conversion network circuit, the first inductor L1 and the three-winding transformer T1 comprise the same magnetic core or different magnetic cores respectively; in a specific embodiment, the switches contained in the conversion circuit can be SiC (silicon carbide), GaN (gallium nitride), IGBT (insulated gate bipolar transistor) and MOSFET (metal oxide semiconductor field effect transistor) switches; the first inductor L1 is a resonant inductor and is used for storing and transmitting energy; the first capacitor C1 and the second capacitor C2 are DC blocking capacitors and are used for blocking DC signals and allowing AC signals to pass through at the same time.

[0041] The first coil L2_W1 and the second coil L2_W2 of the double-channel magnetic coupling inductor L2 share a part of the magnetic core and form a magnetic circuit coupling, so that the device size is effectively reduced, the magnetic material loss is reduced, and the cost is reduced.

[0042] Please refer to Figure 1 and Figure 12 The external ports of the first bridge circuit, the second bridge circuit and the voltage transformation circuit are DC ports and are used for connecting a power supply or a load.

[0043] In a specific implementation: the external ports of the first bridge circuit, the second bridge circuit and the transformer circuit are DC ports, and are used for connecting a power supply or a load, wherein any one of the external ports is selected to connect the power supply, and the remaining two external ports are used for connecting the load, forming a three-port bidirectional dual-port output circuit, in a specific embodiment, the external port of the first bridge circuit is a first DC port Vdc1, the external port of the second bridge circuit is a second DC port Vdc2, and the external port of the transformer circuit is a third DC port Vdc3; there are three kinds of input and output conditions of the external ports, in the first condition, when the first DC port Vdc1 of the first bridge circuit is connected to the power supply, the second DC port Vdc2 of the second bridge circuit and the third DC port Vdc3 of the transformer circuit can be connected to the load, the current flows in from the first DC port Vdc1 and flows out from the second DC port Vdc2 and the third DC port Vdc3 respectively; in the second condition, when the second DC port Vdc2 of the second bridge circuit is connected to the power supply, the first DC port Vdc1 of the first bridge circuit and the third DC port Vdc3 of the transformer circuit can be connected to the load, the current flows in from the second DC port Vdc2 and flows out from the first DC port Vdc1 and the third DC port Vdc3 respectively; in the third condition, when the third DC port Vdc3 of the transformer circuit is connected to the power supply, the first DC port Vdc1 of the first bridge circuit and the second DC port Vdc2 of the second bridge circuit can be connected to the load, the current flows in from the third DC port Vdc3 and flows out from the first DC port Vdc1 and the second DC port Vdc2 respectively; bidirectional dual-port output is realized, and functions such as battery charging management, battery discharging management and circuit loop pre-charging are also realized; the utility model mainly discusses the first condition, in a specific embodiment, the first condition can be specifically applied to a new energy automobile, the first DC port Vdc1 is connected to a commercial power supply and is used for inputting power to a conversion circuit, the second DC port Vdc2 is used for charging a power battery of the new energy automobile, and the third DC port Vdc3 is used for supplying power to low-voltage equipment on the vehicle.

[0044] More specifically, Figure 4 , Figure 5 and Figure 6 is a simulation diagram obtained in the case that the current flows in from the first DC port Vdc1 and the current flows out from the second DC port Vdc2 and the third DC port Vdc3 respectively, Figure 4 respectively including a voltage-time transformation curve diagram of the first winding T1_W1 end, the second winding T1_W2 end and the third winding T1_W3 end of the three-winding transformer T1, Figure 5 is a current-time change diagram of the first inductor L1 and the double-channel magnetic coupling inductor L2, Figure 6 is a current-time change diagram of the first DC port Vdc1, the second DC port Vdc2 and the third DC port Vdc3; Figure 7 , Figure 8and Figure 9 Simulation waveforms obtained in the case where the current flows in from the second DC port Vdc2 and the current flows out from the first DC port Vdc1 and the third DC port Vdc3 respectively, Figure 10 , Figure 11 and Figure 12 Simulation waveforms obtained in the case where the current flows in from the third DC port Vdc3 and the current flows out from the first DC port Vdc1 and the second DC port Vdc2 respectively; in a specific embodiment, the dual-channel magnetic coupling inductor L2 includes a first coil L2_W1 and a second coil L2_W2, and the coil pins do not have fixed polarity directions, so two current conversion curves need to be determined according to the specific connection mode of the coils; the first port transformer voltage refers to the voltage at the end of the first winding T1_W1 of the transformer, the second port transformer voltage refers to the voltage at the end of the second winding T1_W2 of the transformer, and the third port transformer voltage refers to the voltage at the end of the third winding T1_W3 of the transformer.

[0045] Please refer to Figure 1 The first bridge circuit, the second bridge circuit and the transformer circuit are connected to the isolation current conversion network circuit respectively, the isolation current conversion network circuit includes a first capacitor C1, a first inductor L1, a second capacitor C2 and a three-winding transformer T1, the transformer includes a first winding T1_W1, a second winding T1_W2 and a third winding T1_W3, the first capacitor C1, the first inductor L1 and the first winding T1_W1 are connected in series and are connected to the first bridge arm and the second bridge arm respectively, the second capacitor C2 and the second winding T1_W2 are connected in series and are connected to the third bridge arm and the fourth bridge arm respectively, the third winding T1_W3 is connected to the ninth switch Q9 and the tenth switch Q10 respectively, and the isolation current conversion network circuit is used to provide electrical isolation; in the isolation current conversion network circuit, the first inductor L1 and the three-winding transformer T1 include the same magnetic core or different magnetic cores respectively.

[0046] In a specific implementation, the first bridge circuit, the second bridge circuit and the voltage transformation circuit are respectively connected to the isolation current conversion network circuit, the isolation current conversion network circuit comprises a first capacitor C1, a first inductor L1, a second capacitor C2 and a three-winding transformer T1, the transformer comprises a first winding T1_W1, a second winding T1_W2 and a third winding T1_W3, the first capacitor C1, the first inductor L1 and the first winding T1_W1 are connected in series, and one end is connected between the first switch Q1 and the third switch Q3, and the other end is connected between the second switch Q2 and the fourth switch Q4, the second capacitor C2 and the second winding T1_W2 are connected in series, and one end is connected between the fifth switch Q5 and the seventh switch Q7, and the other end is connected between the sixth switch Q6 and the eighth switch Q8, and the third winding T1_W3 is connected to the ninth switch Q9 and the tenth switch Q10 respectively, and the isolation current conversion network circuit is used to provide electrical isolation; in the isolation current conversion network circuit, the first inductor L1 and the three-winding transformer T1 are wound using different magnetic cores, at this time, the first inductor L1 and the three-winding transformer T1 are connected in series in a non-magnetic coupling form; the first inductor L1 and the three-winding transformer T1 are wound using the same magnetic core, at this time, the inductive magnetic flux of the first inductor L1 is generated by the leakage inductance between the first winding T1_W1 and the second winding T1_W2 in the three-winding transformer T1, that is, the first inductor L1 and the three-winding transformer T1 are connected in series in a magnetic coupling form; in a specific embodiment, the series connection order of the first capacitor C1, the first inductor L1 and the first winding T1_W1 is not fixed, and the series connection order of the second capacitor C2 and the second winding T1_W2 is not fixed.

[0047] Please refer to Figures 1-3 , the first bridge circuit comprises a first switch Q1, a second switch Q2, a third switch Q3 and a fourth switch Q4, the first switch Q1 and the third switch Q3 form a first bridge arm, the second switch Q2 and the fourth switch Q4 form a second bridge arm, the first bridge arm and the second bridge arm are connected in parallel with each other, the on-off time of the first switch Q1 and the third switch Q3 is opposite, the on-off time of the second switch Q2 and the fourth switch Q4 is opposite, and the control of the voltage and current size and direction flowing into the second bridge circuit and the voltage transformation circuit is realized by controlling the on-off time of the first switch Q1, the second switch Q2, the third switch Q3 and the fourth switch Q4.

[0048] In a specific implementation: the first bridge circuit includes a first switch Q1, a second switch Q2, a third switch Q3 and a fourth switch Q4, the first switch Q1 and the third switch Q3 form a first bridge arm, the second switch Q2 and the fourth switch Q4 form a second bridge arm, the first bridge arm and the second bridge arm are connected in parallel to the first DC port Vdc1, the first switch Q1 and the third switch Q3 have opposite on-off times, the second switch Q2 and the fourth switch Q4 have opposite on-off times, the first switch Q1 and the fourth switch Q4 have the same on-off time, the second switch Q2 and the third switch Q3 have the same on-off time, and the on-off times of the first switch Q1, the second switch Q2, the third switch Q3 and the fourth switch Q4 are controlled to control the voltage and current flowing into the second bridge circuit and the voltage and current flowing into the voltage transformation circuit; in a specific embodiment, the on-off times of the first switch Q1, the second switch Q2, the third switch Q3 and the fourth switch Q4 determine the current and voltage of the first winding T1_W1, the first winding T1_W1, the second winding T1_W2 and the third winding T1_W3 are coupled, and the current and voltage of the second winding T1_W2 and the third winding T1_W3 are determined, that is, the voltage and current flowing into the second bridge circuit and the voltage and current flowing into the voltage transformation circuit are controlled.

[0049] Please refer to Figures 1-3 , the second bridge circuit includes a fifth switch Q5, a sixth switch Q6, a seventh switch Q7, an eighth switch Q8 and a third capacitor C3, the fifth switch Q5 and the seventh switch Q7 form a third bridge arm, the sixth switch Q6 and the eighth switch Q8 form a fourth bridge arm, the third bridge arm, the fourth bridge arm and the third capacitor C3 are connected in parallel, the on-off times of the fifth switch Q5 and the seventh switch Q7 are opposite, the on-off times of the sixth switch Q6 and the eighth switch Q8 are opposite, and the on-off times of the fifth switch Q5, the sixth switch Q6, the seventh switch Q7 and the eighth switch Q8 are controlled to control the voltage and current of the output port of the second bridge circuit.

[0050] In a specific implementation: the second bridge circuit includes a fifth switch Q5, a sixth switch Q6, a seventh switch Q7, an eighth switch Q8 and a third capacitor C3, the fifth switch Q5 and the seventh switch Q7 form a third bridge arm, the sixth switch Q6 and the seventh switch Q7 form a fourth bridge arm, the third bridge arm, the fourth bridge arm and the third capacitor C3 are connected in parallel to the second DC port Vdc2, the on-off time of the fifth switch Q5 and the seventh switch Q7 is opposite, the on-off time of the sixth switch Q6 and the eighth switch Q8 is opposite, the on-off time of the fifth switch Q5 and the eighth switch Q8 is the same, the on-off time of the sixth switch Q6 and the seventh switch Q7 is the same, and the output voltage and current size and direction of the second bridge circuit are controlled by controlling the on-off time of the fifth switch Q5, the sixth switch Q6, the seventh switch Q7 and the eighth switch Q8. In a specific embodiment, when charging the load of the second DC port Vdc2, the output voltage and current size and direction of the second bridge circuit are controlled by controlling the on-off time of the fifth switch Q5, the sixth switch Q6, the seventh switch Q7 and the eighth switch Q8 according to the voltage and current size and direction on the second winding T1_W2.

[0051] Please refer to Figures 1-18 The transformer circuit includes a double-channel magnetic coupling inductor L2, a ninth switch Q9, a tenth switch Q10, an eleventh switch Q11, a twelfth switch Q12 and a fourth capacitor C4. The double-channel magnetic coupling inductor L2 includes a first coil L2_W1, a second coil L2_W2, a shared magnetic core 1 and a non-shared magnetic core 2, and the first coil L2_W1 and the second coil L2_W2 are magnetically coupled through the shared magnetic core 1. The ninth switch Q9, the twelfth switch Q12 and the first coil L2_W1 of the double-channel magnetic coupling inductor L2 form a first BUCK branch, the tenth switch Q10, the eleventh switch Q11 and the second coil L2_W2 of the double-channel magnetic coupling inductor L2 form a second BUCK branch, the first BUCK branch and the second BUCK branch share the fourth capacitor C4 and form two interleaved BUCK branches, the on-off time of the ninth switch Q9 and the twelfth switch Q12 is opposite, the on-off time of the tenth switch Q10 and the eleventh switch Q11 is opposite, and the ninth switch Q9 and the tenth switch Q10 form a phase difference of 0 to 180 degrees. The output voltage and current size and direction of the transformer circuit are controlled by controlling the on-off time of the ninth switch Q9, the tenth switch Q10, the eleventh switch Q11 and the twelfth switch Q12.

[0052] In a specific implementation: the voltage transformation circuit includes a double-channel magnetic coupling inductor L2, the double-channel magnetic coupling inductor L2 includes a first coil L2_W1, a second coil L2_W2, and a shared magnetic core 1, the shared magnetic core 1 is located in the middle of the first coil L2_W1 and the second coil L2_W2, and the first coil L2_W1 is magnetically coupled with the second coil L2_W2 through the shared magnetic core 1, the first coil L2_W1 and the second coil L2_W2 act on different branches of the voltage transformation circuit respectively, so that the voltage transformation circuit forms a double-BUCK circuit in staggered parallel connection, wherein the BUCK circuit of the DC-DC is a kind of bucking circuit, which realizes the voltage conversion from DC to DC; the voltage transformation circuit further includes a ninth switch Q9, a tenth switch Q10, an eleventh switch Q11, a twelfth switch Q12, and a fourth capacitor C4, the ninth switch Q9, the twelfth switch Q12, and the first coil L2_W1 of the double-channel magnetic coupling inductor L2 form a first BUCK branch, the tenth switch Q10, the eleventh switch Q11, and the second coil L2_W2 of the double-channel magnetic coupling inductor L2 form a second BUCK branch, the first BUCK branch and the second BUCK branch share the fourth capacitor C4, and form two BUCK branches in staggered parallel connection, the on-off time of the ninth switch Q9 and the twelfth switch Q12 is opposite, the on-off time of the tenth switch Q10 and the eleventh switch Q11 is opposite, and the ninth switch Q9 and the tenth switch Q10 form a phase difference of 0 to 180 degrees, and the on-off time of the ninth switch Q9, the tenth switch Q10, the eleventh switch Q11, and the twelfth switch Q12 is controlled to realize the control of the output voltage and current size and direction of the external port of the voltage transformation circuit; in a specific embodiment, according to the voltage and current size and direction on the third winding T1_W3, the on-off time of the ninth switch Q9, the tenth switch Q10, the eleventh switch Q11, and the twelfth switch Q12 is controlled, so as to realize the control of the output voltage and current size and direction of the external port of the voltage transformation circuit, wherein, as shown in Figure 17 , the current of the first coil L2_W1 and the second coil L2_W2 of the double-channel magnetic coupling inductor L2 has a certain phase difference, as shown in Figure 18 , the current of the first coil L2_W1 and the second coil L2_W2 is superimposed, so that the third DC port Vdc3 outputs DC, so as to reduce the ripple current and the core loss; the double-BUCK circuit in staggered parallel connection realizes the voltage conversion from DC to DC, effectively improves the conversion efficiency of the third DC port Vdc3, and effectively reduces the output current ripple.

[0053] Please refer to Figure 2 and Figure 16The application discloses a device based on a magnetic coupling double-BUCK three-port bidirectional conversion circuit, which comprises a first bridge module 10, a second bridge module 20, a voltage transformation module 30, an isolated current conversion module 50 and a controller 40 (Controller). The isolated current conversion module 50 is used for connecting the first bridge module 10, the second bridge module 20 and the voltage transformation module 30 to form electrical isolation. The external ports of the first bridge module 10, the second bridge module 20 and the voltage transformation module 30 are all direct current ports and are used for connecting power supplies or loads. The controller 40 comprises an acquisition module 401, an analysis module 402 and a control module 403 and is used for controlling the on-off of switches in the first bridge module 10, the second bridge module 20 and the voltage transformation module 30 to control the size of output voltages and currents of the external ports. The voltage transformation module 30 comprises a double-channel magnetic coupling inductor L2. The double-channel magnetic coupling inductor L2 comprises a non-shared magnetic core 2, a coil and a shared magnetic core 1. The coil comprises a first coil L2_W1 and a second coil L2_W2. A reserved space is arranged between the shared magnetic core 1 and the non-shared magnetic core 2. The first coil L2_W1 and the second coil L2_W2 are located in the reserved space. The shared magnetic core 1 is located between the first coil L2_W1 and the second coil L2_W2, so that the first coil L2_W1 and the second coil L2_W2 form a magnetic circuit coupling.

[0054] In specific implementation, the voltage transformation module 30 comprises the double-channel magnetic coupling inductor L2. The double-channel magnetic coupling inductor L2 comprises the non-shared magnetic core 2, the coil and the shared magnetic core 1. The coil comprises the first coil L2_W1 and the second coil L2_W2. A reserved space is arranged between the shared magnetic core 1 and the non-shared magnetic core 2. The first coil L2_W1 and the second coil L2_W2 are located in the reserved space. The shared magnetic core 1 is located between the first coil L2_W1 and the second coil L2_W2, so that the first coil L2_W1 and the second coil L2_W2 form a magnetic circuit coupling. The device volume is effectively reduced, the magnetic material loss is reduced, and the cost is reduced.

[0055] More specifically, refer to Figure 16 , Figure 16 It is a magnetic simulation diagram of the double-channel magnetic coupling inductor L2. When current flows into the double-channel magnetic coupling inductor L2, the double-channel magnetic coupling inductor L2 converts electric energy into magnetic energy and stores the magnetic energy. In the diagram, red represents a very high magnetic flux density. The redder the magnetic flux density is, the greater the loss is and the more serious the heat generation is. Green represents a medium level of magnetic flux density, smaller loss and smaller heat generation. Blue represents a very small magnetic flux density or even zero. As shown in the simulation diagram, a large area of the shared magnetic core 1 of the two inductors is green, and even a blue area appears. It is indicated that after mutual superposition and offset of the magnetic fields of the shared magnetic circuits, the loss of the magnetic material is greatly reduced, the conversion efficiency is improved, and the heat generation of the inductor is reduced.

[0056] It should be noted that, in the present document, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "comprises a", "comprising", or "comprises" does not, without further restriction, exclude the existence of additional elements of the process, method, article, or apparatus that comprises the element.

[0057] The preferred embodiments of the present application have been described above with the intent to enable those skilled in the art to make and use it. Various modifications to these embodiments will occur to those skilled in the art and are intended to be encompassed by the present application. Therefore, it is to be understood that, within the scope of the present application, the application can be practiced otherwise than as specifically described. For example, the order of steps can be varied, or some steps can be omitted or adapted; the use of some reagents can be tailored or made redundant, and other suitable endpoints and parameters can be employed.

Claims

1. A magnetic-coupling-based dual-BUCK three-port bidirectional conversion circuit, characterized in that, The isolation current conversion network circuit is used for providing electrical isolation; The first bridge circuit, the second bridge circuit and the voltage conversion circuit are all direct current ports and are used for connecting power supply or load.

2. The magnetic-coupling-based dual-BUCK three-port bidirectional conversion circuit according to claim 1, wherein, The voltage conversion circuit further comprises a ninth switch, a tenth switch, an eleventh switch, a twelfth switch and a fourth capacitor, the ninth switch, the twelfth switch and the first coil of the double-channel magnetic coupling inductor form a first BUCK branch, the tenth switch, the eleventh switch and the second coil of the double-channel magnetic coupling inductor form a second BUCK branch, the first BUCK branch and the second BUCK branch are cross-parallel, and share the fourth capacitor; 3. The magnetic-coupled dual-BUCK three-port bidirectional conversion circuit according to claim 1, wherein, The on-off time of the ninth switch and the twelfth switch is opposite, the on-off time of the tenth switch and the eleventh switch is opposite, and the ninth switch and the tenth switch form an angle phase difference of 0 to 180 degrees. The first bridge circuit comprises a first switch, a second switch, a third switch and a fourth switch, the first switch and the third switch form a first bridge arm, the second switch and the fourth switch form a second bridge arm, the first bridge arm and the second bridge arm are parallel to each other, the on-off time of the first switch and the third switch is opposite, and the on-off time of the second switch and the fourth switch is opposite.

4. The magnetic-coupled dual-BUCK three-port bidirectional conversion circuit according to claim 1, wherein, The second bridge circuit comprises a fifth switch, a sixth switch, a seventh switch, an eighth switch and a third capacitor, the fifth switch and the seventh switch form a third bridge arm, the sixth switch and the eighth switch form a fourth bridge arm, the third bridge arm, the fourth bridge arm and the third capacitor are parallel to each other, the on-off time of the fifth switch and the seventh switch is opposite, and the on-off time of the sixth switch and the eighth switch is opposite.

5. The magnetic-coupled dual-BUCK three-port bidirectional conversion circuit according to claim 1, wherein, The isolation current conversion network circuit comprises a first capacitor, a first inductor, a second capacitor and a three-winding transformer, the transformer comprises a first winding, a second winding and a third winding, the first capacitor, the first inductor and the first winding are connected in series, the second capacitor and the second winding are connected in series, and the third winding is connected with the ninth switch and the tenth switch respectively.

6. The magnetic-coupled dual-BUCK three-port bidirectional conversion circuit based on claim 3, wherein, In the isolation current conversion network circuit, the first inductor and the three-winding transformer comprise the same magnetic core or different magnetic cores respectively. ​ 7. An apparatus based on a magnetic-coupled dual-BUCK three-port bidirectional conversion circuit, characterized in that, The application relates to a voltage and current conversion circuit, which comprises a first bridge module, a second bridge module, a voltage conversion module, an isolated current conversion module and a controller, the isolated current conversion module is used for connecting the first bridge module, the second bridge module and the voltage conversion module to form electrical isolation, the external connection ports of the first bridge module, the second bridge module and the voltage conversion module are DC ports, the external connection ports are used for connecting a power supply or a load, the controller comprises a collection module, an analysis module and a control module, the analysis module is electrically connected with the collection module and the control module respectively, and the controller controls the on-off of switches in the first bridge module, the second bridge module and the voltage conversion module to control the voltage and current output by the voltage and current conversion circuit.

8. The apparatus based on the magnetic-coupled dual-BUCK three-port bidirectional conversion circuit according to claim 7, characterized in that, The voltage conversion module comprises a double-channel magnetic coupling inductor, the double-channel magnetic coupling inductor comprises a shared magnetic core, a coil and a non-shared magnetic core, the coil comprises a first coil and a second coil, a reserved space is arranged between the shared magnetic core and the non-shared magnetic core, the first coil and the second coil are located in the reserved space, and the shared magnetic core is located between the first coil and the second coil, so that the first coil and the second coil are coupled to form a magnetic circuit.

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