阅读说明：本技术 一种隔离型集成化三端口双向dcdc变换器 (Isolated integrated three-port bidirectional DCDC converter ) 是由 马皓 高祎韩 于 2019-09-09 设计创作，主要内容包括：本发明公开了一种隔离型集成化三端口双向DCDC变换器,包括集成化变压器T和I端口、II端口、III端口；所述的集成化变压器T,包括一个集成化变压器T的磁芯、一个I端口侧绕组N<Sub>p1</Sub>、两个II端口侧绕组N<Sub>P21</Sub>和N<Sub>P22</Sub>、一个III端口侧绕组N<Sub>P3</Sub>；所述的集成化变压器T的磁芯,包括三个磁柱,分别为第一磁柱、中柱、第二磁柱；所述的I端口侧绕组N<Sub>p1</Sub>和II端口侧绕组N<Sub>P21</Sub>均绕制在第一磁柱和第二磁柱上,所述的II端口侧绕组N<Sub>P22</Sub>和III端口侧绕组N<Sub>P3</Sub>均绕制在中柱上。该隔离型集成化三端口双向DCDC变换器可以实现三个端口的能量的双向传输,且任意两个端口传输能量时,第三个端口可以实现带载和空载运行。同时,该拓扑通过磁集成的方式,使得变压器数量仅为一个,有利于高效率和高功率密度的实现。(The invention discloses an isolated integrated three-port bidirectional DCDC converter, which comprises an integrated transformer T, an integrated transformer I port, an integrated transformer II port and an integrated transformer III port; the integrated transformer T comprises a magnetic core of the integrated transformer T and an I port side winding N p1 Two II port side windings N P21 And N P22 A III port side winding N P3 (ii) a The magnetic core of the integrated transformer T comprises three magnetic columns, namely a first magnetic column, a middle column and a second magnetic column; the I port side winding N p1 And II port side winding N P21 Are wound on the first magnetic pole and the second magnetic pole, and the end opening side winding N of the II port P22 And III Port side winding N P3 Are wound on the central column. The isolated integrated three-port bidirectional DCDC converter can realize bidirectional transmission of energy of three ports, and when any two ports transmit energy, the third port can realize on-load and no-load operation. Meanwhile, the topology is in a magnetic integration mode, so that the number of the transformers is only one, and high efficiency is facilitatedAnd the realization of high power density.)

1. An isolated integrated three-port bidirectional DCDC converter is characterized by comprising integrated transformer T and I ports, II ports and III ports;

the integrated transformer T comprises a magnetic core of the integrated transformer T and an I port side winding N_p1Two II port side windings N_P21And N_P22A III port side winding N_P3(ii) a The magnetic core of the integrated transformer T comprises three magnetic columns, namely a first magnetic column, a middle column and a second magnetic column; the I port side winding N_p1And II port side winding N_P21Are wound on the first magnetic pole and the second magnetic pole, and the end opening side winding N of the II port_P22And III Port side winding N_P3All are wound on the central column;

the I port side winding N_p1And II port side winding N_P21Winding mode of coils on the first magnetic pole and the second magnetic pole is that the winding N is observed from the top end or the lower end of the integrated transformer T_p1And winding N_P21The number of turns of the coils on the first magnetic pole and the second magnetic pole are completely the same, and the winding directions are opposite;

the I port comprises a first input/outputOut end V₁A first resonant capacitor C_r1A first resonant inductor L_r1A first input/output terminal inversion/rectification network 1; the first input/output end inversion/rectification network 1 is in a full-bridge circuit structure or a half-bridge circuit structure;

the II port comprises a second input/output end V₂A second input/output capacitor C₂A second resonant capacitor C_r2A second input/output end three half-bridge inversion/rectification network 2; the second input/output end three-half-bridge inversion/rectification network 2 comprises three switch bridge arm pairs, each switch bridge arm pair comprises two switch tubes, and a source electrode of an upper tube is connected with a drain electrode of a lower tube;

wherein, the II port side winding N_P21The same name end of the second input/output end is connected with the first output end of the second input/output end three-half-bridge inversion/rectification network 2, and a winding N at the side of the port II_P21The different name end and a second resonance capacitor C_r2And a port II side winding N_P22Is connected with the same name terminal of the first resonant capacitor C_r2The other end of the second input/output end is connected with a second output end of a second input/output end three-half-bridge inversion/rectification network 2, and a port II side winding N_P22The different name end of the second input/output end is connected with the third output end of the second input/output end three-half-bridge inversion/rectification network 2, and the drain electrodes of all upper tubes of the second input/output end three-half-bridge inversion/rectification network 2 and a second input/output capacitor C₂Positive electrode and second input/output terminal V₂Is connected with the source of each lower tube of the second input/output end three-half-bridge inversion/rectification network 2 and the second input/output capacitor C₂And a second input/output terminal V₂The negative electrodes are connected;

the III port comprises a third input/output end V₃A third input/output capacitor C₃A third resonant capacitor C_r3A second resonant inductor L_r2A first output inductor L_oA third input/output terminal inverting/rectifying network 3; the third input/output end inversion/rectification network 3 is a phase-shifted full-bridge circuit output side structure or a current doubling circuit output side structure。

2. The isolated integrated three-port bidirectional DCDC converter according to claim 1, wherein said integrated transformer T, I-port side winding N_p1And II port side winding N_P21The number of turns of the first magnetic pole is even, and the winding directions of the first magnetic pole and the second magnetic pole are opposite; II port side winding N_P22And III Port side winding N_P3The winding direction on the center post is the same.

3. The isolated integrated three-port bidirectional DCDC converter according to claim 2, wherein said integrated transformer T, I-port side winding N_p1And II port side winding N_P21Clockwise winding mode of coils on the first magnetic pole and the second magnetic pole, and I port side winding N_p1Winding n from the top end to the bottom end of the first magnetic column clockwise₁Winding n from the bottom end to the top end of the second magnetic column clockwise after the turn₁Turn, II port side winding N_P21Winding n from the top end of the first magnetic column downwards clockwise₂Winding n from the bottom end of the second magnetic column upwards clockwise after the turn₂Turns; i port side winding N_p1And II port side winding N_P21The coils on the first magnetic pole and the second magnetic pole are wound in a counterclockwise way, and the I port side winding N is adopted_p1Winding n from the top end to the bottom end of the first magnetic column in a counterclockwise way₁Winding n from the bottom end to the top end of the second magnetic pole in a counterclockwise way after the turns₁Turn, II port side winding N_P21Winding n from the top end of the first magnetic column downwards in a counterclockwise way₂Winding n from the bottom end of the second magnetic column upwards in a counterclockwise way after the turn₂And (4) turning.

4. The isolated integrated three-port bidirectional DCDC converter according to claim 1, wherein the full-bridge circuit structure of the first i/o inverting/rectifying network 1 comprises two switch bridge arm pairs and a first i/o capacitor, each switch bridge arm pair comprises two switch tubes, the source of the upper tube is connected to the drain of the lower tube, the bridge arm midpoints of the two switch bridge arm pairs are respectively connected to the first resonant capacitor C_r1And a first resonant inductor L_r1Is connected to a first resonant capacitor C_r1The other end of (1) and the I port side winding N_p1Is connected with the same name terminal of the first resonant inductor L_r1The other end of (1) and the I port side winding N_p1The drain electrodes of the upper tubes of the two switch bridge arm pairs are connected with the first input/output end V₁Is connected with the anode of the first input/output capacitor, and the source of the lower tube of the two switch bridge arm pairs is connected with the first input/output end V₁Is connected to the cathode of the first input/output capacitor.

5. The isolated integrated three-port bidirectional DCDC converter according to claim 1, wherein the half-bridge circuit structure of the first i/o inverter/rectifier network 1 comprises a switch arm pair and a capacitor arm pair, the switch arm pair comprises two switch tubes, the source of the upper tube is connected to the drain of the lower tube, the capacitor arm pair comprises two capacitors connected in series, and the arm midpoint of the switch arm pair and the first resonant capacitor C are connected in series_r1Is connected with the first resonant inductor L, the middle point of the bridge arm of the capacitor bridge arm pair and the first resonant inductor L_r1Is connected to a first resonant capacitor C_r1The other end of (1) and the I port side winding N_p1Is connected with the same name terminal of the first resonant inductor L_r1The other end of (1) and the I port side winding N_p1The synonym end of the switch bridge arm pair is connected with the drain electrode of the upper tube of the switch bridge arm pair, the top end of the capacitor bridge arm pair and the first input/output end V₁The source of the lower tube of the switch bridge arm pair is connected with the bottom end of the capacitor bridge arm pair and the first input/output end V₁Are connected with each other.

6. The isolated integrated three-port bidirectional DCDC converter according to claim 1, wherein said phase-shifted full-bridge output structure of the third I/O inverter/rectifier network 3 comprises two switch bridge arm pairs, each switch bridge arm pair comprises two switch tubes, the source of the upper tube is connected to the drain of the lower tube, the bridge arm midpoints of the two switch bridge arm pairs are respectively connected to the third resonant capacitor C_r3And one end ofSecond resonant inductor L_r2Is connected to a third resonant capacitor C_r3The other end of (2) and a side winding N of a port III_P3Is connected with the unlike terminal, and a second resonant inductor L_r2The other end of (2) and a side winding N of a port III_P3The same name end of the upper tube is connected with the drain electrode of the upper tube of the two switch bridge arm pairs, and the drain electrode of the upper tube of the two switch bridge arm pairs is connected with the first output inductor L_oIs connected to a first output inductor L_oAnd the other end of the third input/output terminal V₃Positive pole and third input/output capacitor C₃The source electrodes of the lower tubes of the two switch bridge arm pairs are connected with a third input/output end V₃And a third input/output capacitor C₃Are connected with each other.

7. The isolated integrated three-port bidirectional DCDC converter according to claim 1, wherein the current-doubling circuit output side structure of the third i/o inverter/rectifier network 3 comprises a switch bridge arm pair and a filter inductor, the switch bridge arm pair comprises two switch tubes, the source of the upper tube is connected to the source of the lower tube, the middle point of the bridge arm of the switch bridge arm pair is connected to the V-shaped third i/o port₃And a third input/output capacitor C₃Is connected with the drain electrode of the upper tube of the switch bridge arm pair and L of the first output inductor_oAnd a second resonant inductor L_r2Is connected to a first output inductor L_oAnd the other end of the third input/output terminal V₃Positive pole and third input/output capacitor C₃Is connected with the positive pole of the second resonant inductor L_r2The other end of (2) and a side winding N of a port III_P3The drain electrode of the lower tube of the switch bridge arm pair is connected with one end of the filter inductor and the third resonant capacitor C_r3Is connected to one end of the filter inductor, and the other end of the filter inductor is connected to a third input/output terminal V₃Positive pole of and third input/output capacitor C₃Is connected with the anode of the third resonant capacitor C_r3The other end of (2) and a side winding N of a port III_P3The different name ends are connected.

8. The isolated integrated three-port bidirectional DCDC converter according to claim 1, wherein when said I port and said II port transmit energy, or said II port transmits energy to said III port, a control strategy combining frequency conversion control, phase shift control, or both frequency conversion control and phase shift control is adopted; and the port III transmits energy to the port II, and a control strategy for adjusting the drive duty ratio of the switching tube is adopted.

9. The isolated integrated three-port bidirectional DCDC converter according to claim 1, wherein said isolated integrated three-port bidirectional DCDC converter has an operating frequency that requires a lower regulation limit f higher than said operating frequency_min，f_minThe expression of (a) is:

wherein L is_r1Is a first resonant inductor, C_r1Is a first resonant capacitor, C_r2Is a second resonant capacitor, K₁I-port side winding N for integrated transformer T_p1And II port winding N_P21Turn ratio between.

Technical Field

The invention relates to the technical field of power electronic converters, in particular to an isolated integrated three-port bidirectional DCDC converter.

Background

Along with the increasing problem of environmental pollution and energy shortage, the use of clean energy is more and more emphasized by people, and many countries begin to vigorously develop and promote the use of new energy automobiles. In order to improve the portability of charging new energy automobiles, many automobile manufacturers have proposed the requirements of vehicle-mounted chargers and in-vehicle low-voltage high-current DCDC converters for power supply enterprises. In order to further reduce the size of the in-vehicle power converter and increase the overall power density, a power electronic converter capable of integrating a vehicle-mounted charger with an in-vehicle low-voltage high-current DCDC converter is required.

Based on the traditional active bridge converter, domestic and foreign scholars put forward a series of improvement measures to meet the requirement of three-port bidirectional input and output. For example, in the three-port bidirectional DC/DC converter disclosed in patent specification with publication number CN103904905A, a current-obtaining type full-bridge unit or a current-obtaining type half-bridge unit is connected to one port of a three-winding transformer, and any two of the same or different voltage-obtaining type basic topology units of the current-obtaining type full-bridge unit, the voltage-obtaining type half-bridge unit, the boost type half-bridge unit, and the series resonance type full-bridge unit are respectively connected to the other two winding ports of the three-winding transformer, so as to form the three-port bidirectional DC/DC converter based on phase shift control. According to the scheme, multiple active bridge topologies are combined, bidirectional flow of energy of three ports is realized, but due to overlarge switching loss, the converter is not suitable for a working mode of converting high-voltage low current into low-voltage high current.

The patent specification with publication number CN103208925A discloses an isolated DC-DC converter topology circuit, which comprises a controller, a solar array input end, a bus output end, a storage battery end, a battery port module connected with the storage battery end, and a primary side input module, a transformer module and a bus load output port module which are sequentially connected between the solar array input end and the bus output end; the primary side input module comprises a first MOS tube, a second MOS tube, a first capacitor and a second capacitor which are respectively connected between the anode and the cathode of the input end of the solar array in a half-bridge manner, the grids of the first MOS tube and the second MOS tube are respectively connected with the controller, and a first inductor is connected between the middle point of the first MOS tube and the second MOS tube and the middle point of the first capacitor and the second capacitor; the transformer module also comprises a third inductor and a fourth inductor which are electrically connected; and the bus output port module is connected between two ends of the fourth inductor, and the battery port module is connected between two ends of the third inductor. The converter expands a two-port circuit into a three-port circuit by combining a half-wave rectification circuit and a flyback circuit, but does not have the function that energy of three ports can flow in two directions.

On the premise of realizing the function of bidirectional transmission of three-port energy, in order to ensure higher overall working efficiency, the improvement measures of the existing active bridge converter have certain limitations, so that a new improved topology is urgently needed to realize the bidirectional transmission of the three-port energy under high efficiency.

Disclosure of Invention

Aiming at the above, based on the topology structures of the double-active bridge topology and the phase-shifted full bridge, the invention provides an isolated integrated three-port bidirectional DCDC converter which can realize bidirectional transmission of high-efficiency lower three-port energy.

An isolated integrated three-port bidirectional DCDC converter comprises an integrated transformer T, an integrated transformer I port, an integrated transformer II port and an integrated transformer III port;

the integrated transformer T comprises a magnetic core of the integrated transformer T and an I port side winding N_p1Two II port side windings N_P21And N_P22A III port side winding N_P3(ii) a The magnetic core of the integrated transformer T comprises three magnetic columns, namely a first magnetic column, a middle column and a second magnetic column; the I port side winding N_p1And II port side winding N_P21Are wound on the first magnetic pole and the second magnetic pole, and the end opening side winding N of the II port_P22And III Port side winding N_P3All are wound on the central column;

the I port side winding N_p1And II port side winding N_P21Winding mode of coils on the first magnetic pole and the second magnetic pole is that the winding N is observed from the top end or the lower end of the integrated transformer T_p1And winding N_P21The number of turns of the coils on the first magnetic pole and the second magnetic pole are completely the same, and the winding directions are opposite;

the I port comprises a first input/output end V₁A first resonant capacitor C_r1A first resonant inductor L_r1A first input/output terminal inversion/rectification network 1; the first input/output end inversion/rectification network 1 is fullA bridge circuit configuration or a half-bridge circuit configuration;

the II port comprises a second input/output end V₂A second input/output capacitor C₂A second resonant capacitor C_r2A second input/output end three half-bridge inversion/rectification network 2; the second input/output end three-half-bridge inversion/rectification network 2 comprises three switch bridge arm pairs, each switch bridge arm pair comprises two switch tubes, and a source electrode of an upper tube is connected with a drain electrode of a lower tube;

wherein, the II port side winding N_P21The same name end (2 terminal) of the second input/output end three-half-bridge inversion/rectification network 2 is connected with the first output end (c terminal) of the second input/output end three-half-bridge inversion/rectification network 2, and a winding N at the side of the port II is arranged_P21And a second resonant capacitor C_r2And a port II side winding N_P22Is connected to the same name terminal (2' terminal), and a second resonant capacitor C_r2The other end of the second input/output end is connected with a second output end (a terminal d) of a second input/output end three-half-bridge inversion/rectification network 2, and a winding N at the side of a port II_P22The different name end (2' terminal) of the first input/output end three-half-bridge inversion/rectification network 2 is connected with the third output end (e terminal) of the second input/output end three-half-bridge inversion/rectification network 2, the drain electrode of each upper tube of the second input/output end three-half-bridge inversion/rectification network 2 is connected with the second input/output capacitor C₂Positive electrode and second input/output terminal V₂Is connected with the source of each lower tube of the second input/output end three-half-bridge inversion/rectification network 2 and the second input/output capacitor C₂And a second input/output terminal V₂Are connected with each other.

The III port comprises a third input/output end V₃A third input/output capacitor C₃A third resonant capacitor C_r3A second resonant inductor L_r2A first output inductor L_oA third input/output terminal inverting/rectifying network 3; the third input/output end inversion/rectification network 3 is in a phase-shifted full-bridge circuit output side structure or a current doubling circuit output side structure.

Preferably, the integrated transformer T, I port side winding N_p1And II port side winding N_P21The number of turns of the first magnetic pole is even, and the winding directions of the first magnetic pole and the second magnetic pole are opposite; II port side winding N_P22And III Port side winding N_P3The winding direction on the center post is the same.

More preferably, the integrated transformer T, I port side winding N_p1And II port side winding N_P21Clockwise winding mode of coils on the first magnetic pole and the second magnetic pole, and I port side winding N_p1Winding n from the top end to the bottom end of the first magnetic column clockwise₁Winding n from the bottom end to the top end of the second magnetic column clockwise after the turn₁Turn, II port side winding N_P21Winding n from the top end of the first magnetic column downwards clockwise₂Winding n from the bottom end of the second magnetic column upwards clockwise after the turn₂And (4) turning.

I port side winding N_p1And II port side winding N_P21The coils on the first magnetic pole and the second magnetic pole are wound in a counterclockwise way, and the I port side winding N is adopted_p1Winding n from the top end to the bottom end of the first magnetic column in a counterclockwise way₁Winding n from the bottom end to the top end of the second magnetic pole in a counterclockwise way after the turns₁Turn, II port side winding N_P21Winding n from the top end of the first magnetic column downwards in a counterclockwise way₂Winding n from the bottom end of the second magnetic column upwards in a counterclockwise way after the turn₂And (4) turning.

The preferred winding mode is characterized in that when the I port and the II port transmit energy, the side winding N of the III port is wound_P3No inductive potential is generated, when the port II and the port III transmit energy, the winding N at the side of the port I_p1No induced potential is generated.

The first input/output end inversion/rectification network 1 of the I port is in a full-bridge circuit structure or a half-bridge circuit structure; when the voltage of the I port is lower and the whole transmission power level is lower, a full-bridge circuit can be adopted; when the I-port voltage is high and the overall transmission power level is low, a half-bridge circuit may be used.

Preferably, the full-bridge circuit structure of the first input/output terminal inverter/rectifier network 1 includes two switch bridge arm pairs and a first input/output capacitor, each switch bridge arm pair includes two switch tubes, and a source electrode of the upper tube is in phase with a drain electrode of the lower tubeThe middle points of the bridge arms of the two switch bridge arm pairs are respectively connected with the first resonance capacitor C_r1And a first resonant inductor L_r1Is connected to a first resonant capacitor C_r1The other end of (1) and the I port side winding N_p1Is connected with the same name terminal (1 terminal), a first resonance inductor L_r1The other end of (1) and the I port side winding N_p1The different name end (1' terminal) of the two switch bridge arm pairs are connected, and the drain electrode of the upper tube of the two switch bridge arm pairs is connected with the first input/output end V₁Is connected with the anode of the first input/output capacitor, and the source of the lower tube of the two switch bridge arm pairs is connected with the first input/output end V₁Is connected to the cathode of the first input/output capacitor.

Preferably, the half-bridge circuit structure of the first input/output terminal inverter/rectifier network 1 includes a switch bridge arm pair and a capacitor bridge arm pair, the switch bridge arm pair includes two switch tubes, a source electrode of the upper tube is connected to a drain electrode of the lower tube, the capacitor bridge arm pair includes two capacitors connected in series, a bridge arm midpoint of the switch bridge arm pair and the first resonant capacitor C_r1Is connected with the first resonant inductor L, the middle point of the bridge arm of the capacitor bridge arm pair and the first resonant inductor L_r1Is connected to a first resonant capacitor C_r1The other end of (1) and the I port side winding N_p1Is connected with the same name terminal (1 terminal), a first resonance inductor L_r1The other end of (1) and the I port side winding N_p1The different name end (1' terminal) of the switch bridge arm pair is connected with the drain electrode of the upper tube of the switch bridge arm pair, the top end of the capacitor bridge arm pair and the first input/output end V₁The source of the lower tube of the switch bridge arm pair is connected with the bottom end of the capacitor bridge arm pair and the first input/output end V₁Are connected with each other.

The third input/output end inversion/rectification network 3 of the port III is in a phase-shifted full-bridge circuit output side structure or a current doubling circuit output side structure; when the voltage of the port III is lower and the integral transmission power level is higher, a current doubling circuit output side structure can be adopted; when the voltage of the port III is higher and the integral transmission power level is higher, a phase-shifted full-bridge circuit output side structure can be adopted.

Preferably, the phase-shifted full-bridge circuit of the third input/output terminal inverting/rectifying network 3The output side structure comprises two switch bridge arm pairs, each switch bridge arm pair comprises two switch tubes, the source electrode of the upper tube is connected with the drain electrode of the lower tube, and the middle points of the bridge arms of the two switch bridge arm pairs are respectively connected with the third resonant capacitor C_r3And a second resonant inductor L_r2Is connected to a third resonant capacitor C_r3The other end of (2) and a side winding N of a port III_P3Is connected to the end of the first resonant inductor L (the 3' terminal)_r2The other end of (2) and a side winding N of a port III_P3The same name end (3 terminal) is connected, and the drain electrodes of the upper tubes of the two switch bridge arm pairs are all connected with a first output inductor L_oIs connected to a first output inductor L_oAnd the other end of the third input/output terminal V₃Positive pole and third input/output capacitor C₃The source electrodes of the lower tubes of the two switch bridge arm pairs are connected with a third input/output end V₃And a third input/output capacitor C₃The negative electrodes are connected;

the output side structure of the current-doubling circuit of the third input/output end inversion/rectification network 3 comprises a switch bridge arm pair and a filter inductor, wherein the switch bridge arm pair comprises two switch tubes, the source electrode of an upper tube is connected with the source electrode of a lower tube, and the middle point of the bridge arm of the switch bridge arm pair is connected with a third input/output end V₃And a third input/output capacitor C₃Is connected with the drain electrode of the upper tube of the switch bridge arm pair and L of the first output inductor_oAnd a second resonant inductor L_r2Is connected to a first output inductor L_oAnd the other end of the third input/output terminal V₃Positive pole and third input/output capacitor C₃Is connected with the positive pole of the second resonant inductor L_r2The other end of (2) and a side winding N of a port III_P3The drain electrode of the lower tube of the switch bridge arm pair is connected with one end of the filter inductor and the third resonant capacitor C_r3Is connected to one end of the filter inductor, and the other end of the filter inductor is connected to a third input/output terminal V₃Positive pole of and third input/output capacitor C₃Is connected with the anode of the third resonant capacitor C_r3The other end of (2) and a side winding N of a port III_P3Are connected to the synonym terminal (3' terminal).

When the I port and the II port transmit energy or the II port transmits energy to the III port, the isolated integrated three-port bidirectional DCDC converter adopts a control strategy of combining frequency conversion control, phase-shift control or frequency conversion control and phase-shift control; and when the port III transmits energy to the port II, a control strategy for adjusting the drive duty ratio of the switching tube is adopted.

The variable frequency control is characterized in that the transmission power is controlled by changing the switching frequency of the converter; the phase-shifting control is characterized in that the upper and lower pipes of each bridge arm are complementarily conducted by taking a half switching period as the conducting time, and the phase output by the middle point of the bridge arm of each switching bridge arm of the converter is adjusted to realize the control of the transmission power; the control strategy for adjusting the driving duty ratio of the switching tube is characterized in that the midpoint of the upper tube driving signal of each bridge arm of the third input/output end inversion/rectification network 3 leads/lags the midpoint of the lower tube driving signal by half of the switching period, and the driving duty ratio of each switching tube of the third input/output end inversion/rectification network 3 is adjusted to realize the control of the transmission power.

The working frequency of the isolated integrated three-port bidirectional DCDC converter needs to be higher than the lower regulation limit f of the working frequency_min，f_minThe expression of (a) is:

wherein L is_r1Is a first resonant inductor, C_r1Is a first resonant capacitor, C_r2Is a second resonant capacitor, K₁I-port side winding N for integrated transformer T_p1And II port winding N_P21Turn ratio between.

Preferably, under the phase-shifting control, the working frequency of the isolated integrated three-port bidirectional DCDC converter is the lower limit frequency f_min1.1-2 times of the total amount of the active component.

Preferably, the first resonant inductor L_r1The leakage inductance of the integrated transformer T can be used instead.

Preferably, the second resonant inductor L_r2For use with integrated transformers TThe leakage inductance is replaced.

Compared with the prior art, the invention has the main advantages that:

(1) when any two ports are used for energy transmission, the third port can realize the on-load or off-load operation.

(2) Magnetic isolation exists in any two-port energy transmission process, and the number of the transformers is only one in a magnetic integration mode.

(3) Compared with a non-integrated topology, the number of the switching tubes is reduced.

(4) The control degree of freedom is large, and the device can cope with wide variation of load.

Drawings

Fig. 1 is a schematic diagram of an isolated integrated three-port bidirectional DCDC converter according to an embodiment.

Fig. 2 is a schematic diagram of an operation waveform of the isolated integrated three-port bidirectional DCDC converter according to the embodiment, when the I port is taken as an input port and the II and III ports are taken as output ports as labeled in fig. 1.

Fig. 3 is a schematic diagram of an isolated integrated three-port bidirectional DCDC converter according to an embodiment, where a port III is an input port, a port II is an output port, and the port I is idle as labeled in fig. 1.

Fig. 4 is a schematic cross-sectional winding diagram of an integrated transformer T of the isolated integrated three-port bidirectional DCDC converter according to the embodiment.

Detailed Description

The invention is further described with reference to the following drawings and specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. The experimental procedures, in which specific conditions are not noted in the following examples, are generally carried out under conventional conditions or conditions recommended by the manufacturers.

As shown in fig. 1, the isolated integrated three-port bidirectional DCDC converter of the present embodiment includes three input/output terminals V₁、V₂、V₃Two input/output filter capacitors C₂、C₃A first input/output terminal inverting/rectifying network 1, a second input/output terminal three and a halfA bridge inverter/rectifier network 2, a third I/O inverter/rectifier network 3, two resonant inductors L_r1And L_r2Three resonant capacitors C_r1、C_r2、C_r3An integrated transformer T and an output inductor L_o。

The first I/O inverting/rectifying network 1 includes an I/O capacitor C₁Four switching tubes Q₁、Q₂、Q₃、Q₄Wherein, the switch tube Q₁And Q₃Respectively with Q₂And Q₄Are connected to form two switch bridge arm pairs, Q₁And Q₂Between them is a first output terminal (a terminal), Q₃And Q₄A second output terminal (b terminal) is provided therebetween.

First input/output terminal V₁Anode of and input/output capacitor C of first input/output terminal inverting/rectifying network 1₁Positive pole and upper tube Q of two switch bridge arm pairs₁And Q₃Is connected to the drain of the first input/output terminal V₁And the input/output capacitor C of the first input/output terminal inverting/rectifying network 1₁And the lower tube Q of the two switch bridge arm pairs₂And Q₄Is connected with the source electrode of the first input/output end inversion/rectification network 1, the first output end (a terminal) of the first input/output end inversion/rectification network 1 and the first resonance capacitor C_r1Is connected to a first resonant capacitor C_r1And the other end of the integrated transformer T and an I port side winding N of the integrated transformer T_P1Is connected with the same name end (1 terminal), and is integrated with the I port side winding N of the transformer T_P1And the first resonant inductor L_r1Is connected to one end of a first resonant inductor L_r1And the other end thereof is connected to a second output terminal (b terminal) of the first input/output terminal inverting/rectifying network 1.

The second input/output end three-half-bridge inversion/rectification network 2 comprises six switching tubes Q₅～Q₁₀Wherein, the switch tube Q₅、Q₇And Q₉Respectively with Q₆、Q₈And Q₁₀Are connected to form three switch bridge arm pairs, Q₅And Q₆Between them is a first output terminal (c terminal), Q₇And Q₈Between them is a second output terminal (d terminal), Q₉And Q₁₀A third output end (e terminal) is arranged between the first output end and the second output end; II port side winding N of integrated transformer T_P21Is connected with the first output end (c terminal) of the second input/output end three-half-bridge inversion/rectification network 2.

II port side winding N of integrated transformer T_P21And a second resonant capacitor C_r2And a II port side winding N of the integrated transformer T_P22Is connected to the same name terminal (2' terminal), and a second resonant capacitor C_r2And the other end thereof is connected to a second output terminal (terminal d) of the second input/output terminal tri-half bridge inverter/rectifier network 2.

II port side winding N of integrated transformer T_P22The different name end (2' terminal) of the first input/output end three-half-bridge inversion/rectification network 2 is connected with the third output end (e terminal) of the second input/output end three-half-bridge inversion/rectification network 2, and the upper tube Q of the second input/output end three-half-bridge inversion/rectification network 2₅、Q₇And Q₉Drain electrode of and second input/output capacitor C₂Positive electrode and second input/output terminal V₂Is connected with the positive pole of the second input/output end three-half-bridge inversion/rectification network 2₆、Q₈And Q₁₀Source electrode of and second input/output capacitor C₂And a second input/output terminal V₂Are connected with each other.

The third I/O inversion/rectification network 3 comprises four switching tubes Q₁₁、Q₁₂、Q₁₃、Q₁₄Wherein, the switch tube Q₁₁And Q₁₃Respectively with Q₁₂And Q₁₄Are connected to form two switch bridge arm pairs, Q₁₁And Q₁₂Between them is a first output terminal (f terminal), Q₁₃And Q₁₄A second output terminal (g terminal) is arranged between the first output terminal and the second output terminal.

III-port side winding N of integrated transformer T_P3End of same name (3 terminal) and second resonant inductor L_r2Is connected to one end of a second resonant inductor L_r2And the other end of the first and second input/output terminalsThe first output terminal (f terminal) of the inverting/rectifying network 3 is connected.

III-port side winding N of integrated transformer T_P3And a third resonant capacitor C_r3Is connected to a third resonant capacitor C_r3Is connected with a second output terminal (g terminal) of a third input/output terminal inverting/rectifying network 3, and an upper tube Q of the third input/output terminal inverting/rectifying network 3₁₁And Q₁₃And the first output inductor L_oIs connected to one end of the third input/output terminal inverting/rectifying network 3₁₂And Q₁₄Source electrode of and third input/output capacitor C₃And a third input/output terminal V₃Is connected to the negative pole of the third input/output capacitor C₃Positive pole of and first output inductor L_oAnd the other end and a third input/output terminal V₃The positive electrodes of (a) and (b) are connected.

Winding N_P1And winding N_P21Are wound on the first and second magnetic poles of the integrated transformer T, and a winding N_P22And winding N_P3Are all wound on the center post of the integrated transformer T.

Winding N_P1Has a number of turns of 2n₁Turns, windings N_P21Has a number of turns of 2n₂Turns, windings N_P22Number of turns n₂₂Turns, windings N_P3Number of turns n₃And (4) turning. Winding N_p1Winding n from the top end to the bottom end of the first magnetic column clockwise₁Winding n from the bottom end to the top end of the second magnetic column clockwise after the turn₁Turns, windings N_P21Winding n from the top end of the first magnetic column downwards clockwise₂Winding n from the bottom end of the second magnetic column upwards clockwise after the turn₂Turns, windings N_p22Winding n from the top end of the center pillar to the bottom end clockwise₂₂Turns, windings N_P3Winding n from the top end of the center pillar to the bottom end clockwise₃And (4) turning.

According to the topology shown in fig. 1, nine operating modes are defined:

the first mode is as follows: the I port is used as an energy input port, and the II port and the III port are both used as energy output ports;

and a second mode: the port I is used as an energy input port, the port II is used as an energy output port, and the port III is in no-load operation;

and a third mode: the port II is used as an energy input port, and the ports I and III are used as energy output ports;

and a fourth mode: the port II is used as an energy input port, the port I is used as an energy output port, and the port III is in no-load operation;

and a fifth mode: the port II is used as an energy input port, the port III is used as an energy output port, and the port I is in no-load operation;

mode six: the port III is used as an energy input port, and the ports I and II are used as energy output ports;

mode seven: the port III is used as an energy input port, the port II is used as an energy output port, and the port I is in no-load operation;

and a mode eight: the I port is used as an energy input port, the III port is used as an energy output port, the II port runs in no-load mode, the working state is that the mode I is combined with the mode V at the moment, namely the input energy of the I port is the same as the consumed energy of the III port;

the mode nine: the port III is used as an energy input port, the port I is used as an energy output port, the port II runs in no-load mode, the working state is that the mode four is combined with the mode six at the moment, namely the input energy of the port III is the same as the consumed energy of the port I;

fig. 2 is a schematic diagram of an operating waveform of the isolated integrated three-port bidirectional DCDC converter in a first operating mode. FIG. 2 shows the driving waveforms of the switching tubes at this time, I port inversion/rectification network output voltage waveform v_abOutput voltage waveform v of full-bridge structure formed by port II half-bridge C and half-bridge D_cdOutput voltage waveform v of full-bridge structure formed by port II half-bridge D and half-bridge E_deResonant cavity current I of I-port inversion/rectification network_Lr1And resonant cavity current i of III port inversion/rectification network_Lr2The waveform of (2).

Definition v_abAnd v_cdThe phase angle difference between the fundamental waves of (1) is an outward shift phase angle

The ratio of the phase shift angle to pi is the equivalent phase shift angle of the time domain

D_y1、D_y2、D_y3Are each v_ab、v_cd、v_deThe duty cycle of (c). Because the switching frequency is higher than the series resonance frequency, the input impedance of the resonant cavity is inductive at the moment, and therefore zero voltage switching-on of the I port and the II port can be achieved. The III port adopts a synchronous rectification technology under the working condition, and zero current turn-off can be realized.

Fig. 3 is a schematic diagram of an operating waveform of the isolated integrated three-port bidirectional DCDC converter of the embodiment in the seventh operating mode. FIG. 3 shows the driving waveforms of the switch transistors at ports II and III, and the voltage waveform v at the output end of the inverting/rectifying network at port III_fgResonant capacitor C of port II_r2Current waveform i_Cr2Definition of D_y4Is Q₁₁～Q₁₄The duty cycle of (c). The II port switch tube at this time can be regarded as a diode without driving.

When the isolated integrated three-port bidirectional DCDC converter is in a second working mode or a fourth working mode, the output power P of the II port₁₂Comprises the following steps:

wherein the parameters are defined as follows:

V₁: i port input voltage;

V₂: the port II outputs voltage;

K₁: the turn ratio of the I port transformer coil to the II port transformer coil;

v_aband v_cdThe ratio of the phase angle difference between the fundamental waves to the pi value is-0.5 to 0.5;

D_y1：v_abthe variation range of the duty ratio of (1) is 0-1;

D_y2：v_cdthe variation range of the duty ratio of (1) is 0-1;

Z₀: characteristic impedance of I port expressed as

Wherein the content of the first and second substances,

r: series resonant frequency f₀And the switching frequency f_sAlways less than 1. Wherein the content of the first and second substances,

when the isolated integrated three-port bidirectional DCDC converter is in a fifth working mode, the output power P of the II port₂₃Comprises the following steps:

wherein the parameters are defined as follows:

V₂: inputting voltage at a port II;

V₃: the port III outputs voltage;

K₂: the turn ratio of the coil of the transformer at the port II to the coil at the port III;

D_y3：v_dethe variation range of the duty ratio of (1) is 0-1;

f_s: the switching frequency.

When the isolated integrated three-port bidirectional DCDC converter is in a seventh working mode, the gain M of the converter is₃₂Comprises the following steps:

wherein the parameters are defined as follows:

V₂: the port II outputs voltage;

V₃: inputting voltage at a port III;

K₂: the turn ratio of the coil of the transformer at the port II to the coil at the port III;

D_y4：Q₁₁～Q₁₄the duty ratio of the drive is in the range of 0.5-1.

The other working modes can be combined by a second working mode, a fourth working mode, a fifth working mode and a seventh working mode.

Furthermore, it should be understood that various changes and modifications can be made by one skilled in the art after reading the above description of the present invention, and equivalents also fall within the scope of the invention as defined by the appended claims.