A three-port dual-channel dual active bridge circuit and its dual phase-shift control method

Abstract

This invention discloses a three-port dual-channel dual active bridge circuit and its dual phase-shift control method in the field of power electronics and electrical engineering. Voltage sampling signals and current sampling signals are both sent to the controller. The bus voltage setpoint signal and the bus voltage sampling signal are subtracted by a subtractor to generate a bus voltage error signal, which is sent to the bus voltage controller to output a reference signal. The reference signal and the battery current setpoint signal are subtracted by a subtractor to generate an error signal, which is sent to the corresponding controller to generate the external phase-shift control signal for each channel. The first battery pack voltage sampling signal, the second battery pack voltage sampling signal, and the bus voltage sampling signal are sent to the internal phase-shift controller to generate the internal phase-shift control signal for each channel. This invention stabilizes the DC bus voltage based on different input battery pack voltages through internal and external phase-shift control algorithms.

Description

Technical Field

[0001] This invention relates to the fields of power electronics and electrical engineering, and in particular to a dual-channel dual active bridge circuit and its control method. Background Technology

[0002] There are two main types of power conversion architectures currently used for multi-battery pack collaborative operation: non-isolated converters and isolated converters. The first type typically uses a Buck-Boost circuit structure, directly connecting multiple battery packs to the input of a bidirectional DC / DC converter. The other end of the converter is directly connected to a bus, eliminating the need for a transformer. Voltage boost or buck is controlled solely by adjusting the switching transistors. While this approach is simple, the lack of electrical isolation between battery packs results in lower system safety and makes independent, precise control of the current in each battery pack difficult. The second type of architecture equips each battery pack with an independent isolated DC / DC converter (such as a dual active bridge circuit), achieving electrical isolation through a high-frequency transformer. This provides high safety and allows for independent control of each battery pack. However, this approach requires multiple complete converters and transformers, leading to a large system size, high cost, low power density, and complex coordination control between units. In such architectures, while integrating multiple ports using multi-winding transformers can reduce the number of magnetic components, it generally suffers from severe power coupling between ports, low control freedom, and difficulty in achieving dynamic optimal power allocation based on the actual state of the battery (such as internal resistance and health status). Therefore, existing multi-battery pack energy management solutions struggle to balance high safety, high control precision, high power density, and low system cost, lacking a highly integrated, decoupled control topology and control strategy capable of intelligent power allocation. Summary of the Invention

[0003] To address the shortcomings of existing multi-battery pack systems in balancing safety, power density, cost, and control flexibility, this invention provides a three-port dual-channel dual active bridge circuit and its dual phase-shift control method. Through a deeply integrated topology and intelligent control strategy, it achieves efficient, safe, and independently controllable bidirectional energy flow between the DC bus and two independent battery ports.

[0004] The objective of this invention is achieved as follows:

[0005] A three-port dual-channel dual active bridge circuit includes:

[0006] The circuit consists of a first battery-side dual active bridge full-bridge circuit, a second battery-side dual active bridge full-bridge circuit, and a high-voltage-side dual active bridge full-bridge circuit.

[0007] The DC input ports of the first battery-side dual active bridge full-bridge circuit and the second battery-side dual active bridge full-bridge circuit are respectively connected to the first battery pack and the second battery pack.

[0008] The midpoint of the bridge arm of the first battery-side dual active bridge full-bridge circuit and the midpoint of the bridge arm of the second battery-side dual active bridge full-bridge circuit are connected to the corresponding high-frequency transformer T. r1 and T r2 Primary winding; the high-frequency transformer consists of two T-type windings. r1 T r2 It is made by winding a primary winding and a secondary winding;

[0009] One end of the secondary winding of the high-frequency transformer is connected to the resonant inductor L. s The resonant inductor L is connected in series. s With DC blocking capacitor C b The DC blocking capacitor C is connected in series. b The high-voltage side dual active bridge full-bridge circuit is connected in series with the midpoint of the bridge arm, and the midpoint of the other bridge arm of the high-voltage side dual active bridge full-bridge circuit is connected to the other end of the secondary winding of the high-frequency transformer.

[0010] The DC output port of the high-voltage side dual active bridge full-bridge circuit is connected to the high-voltage DC bus.

[0011] A dual phase-shift control method for a three-port dual-channel dual active bridge circuit includes:

[0012] Step 1) Control the outward shift angle using a closed-loop controller with three voltage outer loops and two current inner loops;

[0013] 1-1) The voltage error signals of each battery pack and bus are combined to form the total current command, which is then decomposed by the distributor and output to the dual active bridge circuits on both sides as current commands.

[0014] 1-2) The first dual active bridge circuit compares the current setpoint with the sampled value, generates an external phase shift angle through the regulator, and drives the switching transistor through PWM modulation, thus forming the current inner loop closed-loop control of the first dual active bridge circuit.

[0015] 1-3) The second dual active bridge circuit compares the current setpoint with the sampled value, generates an external phase shift angle through the regulator, and drives the switching transistor through PWM modulation, thus forming the current inner loop closed-loop control of the second dual active bridge circuit.

[0016] 1-4) When the mode selection switch selects the battery-side voltage regulator, the two dual active bridge circuits charge the corresponding battery packs respectively, and form the charging voltage outer loop by comparing the battery voltage sampling value with the reference voltage.

[0017] 1-5) When the mode selection switch selects the high-voltage side voltage regulator, the two battery packs discharge to power the bus. The bus voltage outer loop is formed by comparing the bus voltage sample value with the reference voltage.

[0018] 1-5) The three voltage outer loops and the two current inner loops together constitute a closed-loop controller for a three-port dual-channel dual active bridge circuit, which controls the magnitude and direction of energy transfer by adjusting the outer shift angle;

[0019] Step 2) Control the inward shift angle using the inward shift controller;

[0020] 2-1) The bus voltage and the voltage of each battery pack are respectively sent to the corresponding internal phase shift regulator to generate an internal shift angle, and then the phase shift angle between the same side switches in the two dual active bridge circuits is controlled by the phase shift control and drive circuit.

[0021] 2-2) The internal phase shift regulator and the phase shift controller constitute the internal angle shift controller, which controls the power distribution ratio between the primary and secondary sides of the transformer by adjusting the phase shift angle of the same-side switching transistors of the dual active bridge circuits on both sides.

[0022] Furthermore, step 1-1) specifically includes: the constant voltage charging reference voltage V of the first battery pack on the battery side. bat_ref1 The voltage sampling value V of the first battery pack on the battery side bat1 The subtraction generates the first battery voltage error signal; the constant voltage charging reference voltage V of the second battery pack on the battery side. bat_ref2 The voltage sampling value V of the second battery pack on the battery side bat2 The subtraction generates a second battery voltage error signal; the high-voltage side bus reference voltage V bus_ref With high voltage side bus voltage V bus The subtraction generates a bus voltage error signal; the first battery voltage error signal, the second battery voltage error signal, and the bus voltage error signal are used as the battery current reference, and then the current reference of the first battery side dual active bridge circuit and the second battery side dual active bridge circuit are output through the current reference distributor.

[0023] Further, steps 1-2) specifically include: the current setpoint of the first battery-side dual active bridge circuit is subtracted from the battery current sample value of the dual active bridge circuit of the first battery pack on the battery side and then sent to the first current regulator on the battery side. The first current regulator on the battery side generates an outer shift angle Φ1. The outer shift angle Φ1 and the first triangular carrier wave are used to generate a first outer phase shift pulse control signal through a phase shift controller. The first outer phase shift pulse control signal generates a corresponding drive signal through a drive circuit to control the switching of the switching transistor in the first dual active bridge circuit, thereby generating the battery current of the first dual active bridge circuit and forming the battery current sample value of the first dual active bridge circuit. The battery current sample value of the first dual active bridge circuit is sent to be subtracted from the current setpoint of the first dual active bridge circuit to form the current inner loop of the first dual active bridge circuit.

[0024] Further, steps 1-3) specifically include: the current setpoint of the second battery-side dual active bridge circuit is subtracted from the battery current sample value of the dual active bridge circuit of the second battery pack on the battery side and then sent to the second current regulator on the battery side. The second current regulator on the battery side generates an outer shift angle Φ2. The outer shift angle Φ2 and the second triangular carrier are used to generate a second outer phase shift pulse control signal through a phase shift controller. The second outer phase shift pulse control signal is used to generate a corresponding drive signal through a drive circuit to control the switching of the switching transistor in the second dual active bridge circuit, thereby generating the battery current of the second dual active bridge circuit and forming the battery current sample value of the second dual active bridge circuit. The battery current sample value of the second dual active bridge circuit is sent to be subtracted from the current setpoint of the second dual active bridge circuit to form the current inner loop of the second dual active bridge circuit.

[0025] Further, steps 1-4) specifically include: if the outputs of the first battery-side voltage regulator and the second battery-side voltage regulator are selected by the mode selection switch, then the battery current of the first dual active bridge circuit charges the battery pack in the first dual active bridge circuit, generating the battery-side battery voltage of the first dual active bridge circuit and forming the battery-side battery pack voltage sampling value V of the first dual active bridge circuit. bat1 The battery pack voltage sampling value V on the battery side of the first dual active bridge circuit. bat1 Send a constant voltage charging reference voltage V to the first battery pack on the battery side. bat_ref1 Subtracting these values ​​creates the outer loop of the battery charging voltage for the first dual active bridge circuit; the battery current in the second dual active bridge circuit charges the battery pack within the second dual active bridge circuit, generating the battery-side voltage of the second dual active bridge circuit and forming the sampled voltage value V of the second battery pack on the battery side of the second dual active bridge circuit. bat2 The battery pack voltage sampling value V on the battery side of the second dual active bridge circuit. bat2 Sending a constant voltage charging reference voltage V to the second battery on the battery side bat_ref2 Subtracting these values ​​creates the outer loop of the battery charging voltage in the second dual active bridge circuit.

[0026] Furthermore, steps 1-5) specifically include: if the output of the high-voltage side voltage regulator is selected by the mode selection switch, then both the battery packs of the first dual active bridge circuit and the battery packs of the second dual active bridge circuit discharge to provide energy to the bus, generating the high-voltage side bus voltage and forming the high-voltage side bus voltage sampling value V. bus The sampled value of the high-voltage side bus voltage is sent to be subtracted from the reference voltage of the high-voltage side bus, thereby forming the outer loop of the bus voltage.

[0027] Further, steps 1-6) specifically include: the inner current loop of the first dual active bridge circuit and the inner current loop of the second dual active bridge circuit constitute the two inner current loops, and the outer battery charging voltage loop of the first dual active bridge circuit, the outer battery charging voltage loop of the second dual active bridge circuit, and the outer bus voltage loop constitute the three outer voltage loops, forming a closed-loop controller of three voltage outer loops and two inner current loops of the three-port dual-channel dual active bridge circuit. By controlling the outward shift angle between the switching transistors of the battery side circuit and the switching transistors of the bus side circuit of the first and second dual active bridge circuits, the magnitude and direction of energy transfer between the battery side and the bus side are controlled.

[0028] Furthermore, step 2-1) specifically includes: in the inner angle controller, the high-voltage side bus voltage sampling value V bus First battery pack voltage sampling value V bat1 The signal is fed into the first internal phase-shift regulator, which generates an internal shift angle δ1. The internal shift angle δ1 and the third triangular carrier phase-shift controller generate a third phase-shift pulse control signal. This third phase-shift pulse control signal is then used by the drive circuit to generate a corresponding drive signal to control the angle difference between the same-side switching transistors in the first dual active bridge circuit. The high-voltage side bus voltage sampling value V... bus Second battery pack voltage sampling value V bat2 The signal is fed into the second inner phase shift regulator, which generates an inner shift angle δ2. The inner shift angle δ2 and the fourth triangular carrier phase shift controller generate a fourth phase shift pulse control signal. The fourth phase shift pulse control signal is driven by the drive circuit to generate a corresponding drive signal to control the angle difference between the same-side switching transistors in the second dual active bridge circuit.

[0029] Further, step 2-2) specifically includes: the first internal phase shifter, the second internal phase shifter, the third phase shifter and the fourth phase shifter constitute the internal angle controller, which controls the power distribution ratio between the two full bridges on the primary and secondary sides of the transformer by controlling the angle between the switching transistors of the same side circuits of the first and second dual active bridges on the battery side.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0031] This invention employs a single multi-winding transformer integrating a bus-side full-bridge and two battery-side full-bridges, avoiding the need for an independent transformer for each battery port. This significantly reduces the number of magnetic components, thus contributing to improved system power density, reliability, and reduced hardware costs. The dual-battery channels of this invention can connect to battery packs with different performance, capacity, or aging states, naturally adapting to battery reuse and heterogeneous hybrid applications, enhancing the versatility and economy of energy storage equipment. More importantly, the proposed internal and external phase-shifting coordinated control strategy, while achieving stable bus voltage and bidirectional energy transmission, intelligently allocates charging and discharging currents based on the actual battery conditions (such as internal resistance, SOC, and temperature) through independent closed-loop control of the current at the two battery ports. Especially during discharge, this strategy dynamically adjusts the output ratio, allowing high-performance, low-internal-resistance batteries to discharge more, while low-performance, high-internal-resistance batteries discharge less or only slightly, thereby optimizing output efficiency at the system level and effectively extending the overall lifespan of the battery pack, further reducing the total lifespan cost.

[0032] This invention is an extension and innovation based on the classic dual active bridge circuit, thus inheriting all the advantages of the dual active bridge circuit: high safety due to the use of high-frequency transformer isolation; and high conversion efficiency through precise phase-shift control, enabling soft switching of the switching transistors over a wide range. The proposed circuit and control method are particularly suitable for applications requiring safe, efficient, and intelligent energy management between the DC bus and multiple battery banks, such as distributed energy storage power stations. Its core control algorithm can be implemented via software programming using a digital controller (such as a DSP), requiring no additional hardware, offering high flexibility and easy functional upgrades. Other advantages and details of this invention will be further elaborated in the specific embodiments. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0034] Figure 1 The schematic diagram of the three-port dual-channel dual active bridge circuit and control method of this invention.

[0035] Figure 2 The schematic diagram of the three-voltage outer loop and two-current inner closed-loop controller and inner phase-shifting controller of the present invention.

[0036] Figure 3 A schematic diagram illustrating the principle of an embodiment of the present invention.

[0037] Figure 4Timing diagram of phase-shifting pulse control signal for battery charging in this embodiment of the invention.

[0038] Figure 5 Timing diagram of the internal phase-shifting signal for battery charging in this embodiment of the invention.

[0039] Figure 6 The charging test waveform of battery 1 when the charging power is 25% in this embodiment of the invention.

[0040] Figure 7 The charging experiment waveform of battery 2 when the charging power is 12.5% ​​in this embodiment of the invention.

[0041] Figure 8 The charging test driving waveform of battery 1 when the charging power is 25% in this embodiment of the invention.

[0042] Figure 9 The charging test driving waveform of battery 2 when the charging power is 12.5% ​​in this embodiment of the invention.

[0043] Figure 10 Timing diagram of phase-shifting pulse control signal for battery discharge in an embodiment of the present invention.

[0044] Figure 11 The discharge waveform of battery 1 in this embodiment of the invention when the discharge power is 12.5%.

[0045] Figure 12 The discharge waveform of battery 2 when its discharge power is 7.5% in this embodiment of the invention.

[0046] Figure 13 The discharge test driving waveform of battery 1 when the discharge power is 12.5% ​​in this embodiment of the invention.

[0047] Figure 14 The discharge drive experimental waveform of battery 2 when the discharge power is 7.5% in this embodiment of the invention.

[0048] Figure 1 Chinese symbol name:

[0049]

[0050] Figure 2 Chinese symbol name:

[0051]

[0052] Other symbol names are the same Figure 1 Chinese symbol name;

[0053] Figure 3 Chinese symbol name same Figure 1 and Figure 2 Symbol names in;

[0054] Figure 4 ~ Figure 14 Chinese symbol name same Figure 1 Symbol names in the text. Detailed Implementation

[0055] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0056] like Figure 1 As shown, the components of this invention are: a three-port dual-channel dual active bridge circuit 1, a closed-loop controller 2 with three voltage outer loops and two current inner loops, a drive circuit 3, and an inner phase-shifting controller 4; wherein the three-port dual-channel dual active bridge circuit 1 is composed of a first dual active bridge circuit 5 and a second dual active bridge circuit 6; the closed-loop controller 3 with three voltage outer loops and two current inner loops and the inner phase-shifting controller 4 can be implemented in the CPU through a program and program configuration.

[0057] like Figure 1 and Figure 2 A three-port dual-channel dual active bridge circuit and its control method are disclosed. The topology of the invented three-port dual-channel dual active bridge circuit 1 is such that the DC terminal of the battery-side full-bridge circuit (composed of Q1-Q4) of the first dual active bridge circuit 5 and the DC terminal of the battery-side full-bridge circuit (composed of Q5-Q8) of the second dual active bridge circuit 6 form dual-channel ports. These dual-channel ports are respectively connected to a first battery pack (the voltage of the first battery pack is V). bat1 ) and the second battery pack (the voltage of the second battery pack is V) bat2 The midpoint of the bridge arm of the battery-side full-bridge circuit (composed of Q1-Q4) of the first dual active bridge circuit 5 and the midpoint of the bridge arm of the battery-side full-bridge circuit (composed of Q5-Q8) of the second dual active bridge circuit 6 are connected to the corresponding high-frequency transformer T. r1 and T r2 The primary winding of the high-frequency transformer, with one end of the secondary winding connected to the resonant inductor L. s DC blocking capacitor C b and the high-voltage side full-bridge circuit (consisting of Q9-Q) 12 (Composition), the resonant inductor L s and DC blocking capacitor C b The DC blocking capacitor C is connected in series. b Connected to the high-voltage side full-bridge circuit (by Q9-Q) 12 The midpoint E of one arm of the high-voltage side full-bridge circuit (composed of Q9-Q) is the midpoint of the high-voltage side full-bridge circuit.12 The midpoint F of the other bridge arm (consisting of Q9-Q) is connected to the other end of the secondary winding; the high-voltage side full-bridge circuit (composed of Q9-Q) 12 The DC end of the structure is connected to the high-voltage DC bus V. bus The unique three-port dual-channel dual active bridge circuit 1 is controlled by a closed-loop controller 2 with three voltage outer loops and two current inner loops, and an inner phase-shift controller 4. The voltage sampling value V of the first battery pack on the battery side... bat1 Voltage sampling value V of battery 2 on the battery side bat2 The current sampling value I of battery 1 in the first dual active bridge circuit 5 bat1 The current sampling value I of the second battery pack in the second dual active bridge circuit 6 bat2 and high-voltage side bus voltage sampling value V bus The signals are sent to the closed-loop controller 2 (three-voltage outer loop and two-current inner loop) and the inner phase-shift controller 4. The closed-loop controller 2 outputs phase-shift pulse control signal 1 and phase-shift pulse control signal 2, and the inner phase-shift controller 4 outputs a third phase-shift pulse control signal and a phase-shift pulse control signal 4. After passing through the drive circuit 3, the corresponding drive signal (v) is generated. drvQ1， v drvQ2， v drvQ3， v drvQ4， v drvQ5， v drvQ6， v drvQ7， v drvQ8， v drvQ9， v drvQ10， v drvQ11 and v drvQ12 ) is used to control the switching transistors (Q1-Q1) in the three-port dual-channel dual active bridge circuit 1. 12 The on / off state of ).

[0058] As shown in the figure, in the closed-loop controller 2 with three voltage outer loops and two current inner loops, the constant voltage charging reference voltage V of the first battery pack on the battery side is... bat_ref1 The voltage sampling value V of the first battery pack on the battery side bat1 The result of the subtraction is sent to the input of the first battery-side voltage regulator, and the output of the first battery-side voltage regulator is sent to the selection switch; the constant voltage charging reference voltage V of the second battery pack on the battery side. bat_ref2 Voltage sampling value V of battery 2 on the battery side bat2 The result of the subtraction is sent to the input of the second battery-side voltage regulator, and the output of the second battery-side voltage regulator is sent to the selector switch; the high-voltage side bus reference voltage V bus_ref Sampling value V of high voltage side bus voltage busThe result of the subtraction is sent to the input terminal of the high-voltage side voltage regulator, and the output of the high-voltage side voltage regulator is sent to the selection switch; the outputs of the first battery-side voltage regulator, the second battery-side voltage regulator, and the high-voltage side voltage regulator are selected by the selection switch and used as the battery current reference I. bat_ref The current command I of the first dual active bridge circuit is then output through the current command distributor. bat1_ref The current given I of the second dual active bridge circuit bat2_ref ;

[0059] The current input I of the first dual active bridge circuit 5 bat1_ref The current sampling value I of the first battery pack in the first dual active bridge circuit bat1 The result after subtraction is sent to the battery-side current regulator 1, which generates an outward shift angle Φ1. The outward shift angle Φ1 and the first triangular carrier wave are used by the phase shift controller to generate a phase shift pulse control signal 1. The phase shift pulse control signal 1 is used by the drive circuit to generate a corresponding drive signal to control the switching transistors (Q1-Q4) in the first dual active bridge circuit 4, thereby generating the battery current of the first battery pack in the first dual active bridge circuit 5 and forming the current sampling value I of the first battery pack in the first dual active bridge circuit 4. bat1 The battery current sampling value I of the first battery pack in the first dual active bridge circuit 5 bat1 The current input I is sent to the first dual active bridge circuit 5. bat1_ref The subtraction of the two currents forms the inner current loop of the first dual active bridge circuit 5.

[0060] The current input I of the second dual active bridge circuit 6 bat2_ref The current sampling value I of the second battery pack in the second dual active bridge circuit bat2 The result after subtraction is sent to the battery-side current regulator 2, which generates an outward shift angle Φ2. The outward shift angle Φ2 and the second triangular carrier wave are used by a phase-shift controller to generate a phase-shift pulse control signal 2. The phase-shift pulse control signal 2 is used by a drive circuit to generate a corresponding drive signal to control the on / off state of the switching transistors (Q5-Q8) in the second dual active bridge circuit 6, thereby generating the battery current of the second battery pack in the second dual active bridge circuit 6 and forming the battery current sampling value I of the second battery pack in the second dual active bridge circuit 6. bat2 The current sampling value I of the second battery pack in the second dual active bridge circuit 6 bat2 The current given I is sent to the second dual active bridge circuit 6. bat2_ref The subtraction of these two values ​​forms the inner current loop of the second dual active bridge circuit 6.

[0061] If the outputs of the first battery-side voltage regulator and the second battery-side voltage regulator are selected by the selector switch, then the battery current I of the first dual active bridge circuit 5 will be...bat1 The first battery pack in the first dual active bridge circuit 5 is charged, generating the battery-side voltage of the first dual active bridge circuit 5 and forming the voltage sampling value V of the first battery pack on the battery side of the first dual active bridge circuit 5. bat1 The battery voltage sampling value V of the first battery pack on the battery side of the first dual active bridge circuit 5. bat1 Send a constant voltage charging reference voltage V to the first battery pack on the battery side. bat_ref1 Subtraction results in the outer loop of the battery charging voltage of the first dual active bridge circuit 5; the battery current I of the second dual active bridge circuit 6... bat2 The second battery pack in the second dual active bridge circuit 6 is charged, generating the battery-side battery voltage of the second dual active bridge circuit 5 and forming the voltage sampling value V of the second battery pack on the battery side of the second dual active bridge circuit 6. bat2 The voltage sampling value V of the second battery pack on the battery side of the second dual active bridge circuit 6. bat2 Send a constant voltage charging reference voltage V to the second battery pack on the battery side. bat_ref2 Subtracting them together forms the outer loop of the battery charging voltage in the second dual active bridge circuit 6.

[0062] If the output of the high-voltage side voltage regulator is selected by the selector switch, the battery in the first dual active bridge circuit 5 and the battery pack in the second dual active bridge circuit 6 both discharge to provide energy to the bus, generating the high-voltage side bus voltage and forming the high-voltage side bus voltage feedback quantity V. bus The high-voltage side bus voltage sampling value V busf Sending the reference voltage V of the high-voltage side bus bus_ref Subtracting them creates the outer loop of the bus voltage.

[0063] The inner current loop of the first dual active bridge circuit 5 and the inner current loop of the second dual active bridge circuit 6 constitute the two inner current loops. The outer battery charging voltage loop of the first dual active bridge circuit 5, the outer battery charging voltage loop of the second dual active bridge circuit 6, and the outer bus voltage loop constitute the three outer voltage loops, thus forming a closed-loop controller 2 with three outer voltage loops and two inner current loops in the three-port dual-channel dual active bridge circuit 1.

[0064] In the inner angle controller 4, the high-voltage side bus voltage sampling value V bus The first battery pack voltage sampling value V bat1 The signal is fed into the first internal phase-shift regulator, which generates an internal shift angle δ1. The internal shift angle δ1 and the triangular carrier phase-shift controller 3 generate a third phase-shift pulse control signal. This third phase-shift pulse control signal is then used by the drive circuit to generate a corresponding drive signal to control the angle difference between the two sets of switching transistors Q1 and Q4, and Q2 and Q3, in the first dual active bridge circuit. The high-voltage side bus voltage sampling value V...bus The second battery pack voltage sampling value V bat2 The signal is fed into the second internal phase shift regulator, which generates an internal shift angle δ2. The internal shift angle δ2 and the fourth triangular carrier phase shift controller generate an internal phase shift pulse control signal 4. The phase shift pulse control signal 4 is driven by the driving circuit to generate a corresponding driving signal to control the angle difference between the two sets of switching transistors Q5, Q8 and Q6, Q7 in the second dual active bridge circuit.

[0065] The first internal phase shifter, the second internal phase shifter, the triangular carrier phase shifter 3, and the fourth triangular carrier phase shifter constitute the internal phase shifter 4.

[0066] The closed-loop controller 2 with three voltage outer loops and two current inner loops, and the inner phase-shift controller 4, can be implemented using digital control chips. The control algorithm is implemented by writing code in software, and the phase-shift control pulse signals 1, 2, 3, and 4 are output. The output phase-shift control pulse signals 1 and 2 control the corresponding switching transistors in the three-port dual-channel dual active bridge circuit 1 through the drive circuit 3, thereby realizing bidirectional energy flow between the battery side and the high-voltage side. The phase-shift control pulse signals 3 and 4 control the angle between the switching transistors in the first dual active bridge circuit 5 and the second dual active bridge circuit 6 in the three-port dual-channel dual active bridge circuit 1 through the drive circuit 3, thereby realizing the power distribution ratio between the two full bridges on the primary and secondary sides of the transformer.

[0067] For the proposed three-port dual-channel dual active bridge circuit, under the dual phase-shift control strategy, by rationally designing the transformer, resonant inductor, DC blocking capacitor, and operating frequency of the switching transistors, soft switching can be achieved under a wide voltage range and full load conditions, thereby significantly reducing switching losses and improving system efficiency. The high-frequency transformer with multiple windings used in this invention couples a circuit topology of one bus-side full bridge and two battery-side full bridges. Compared to the traditional scheme of configuring an independent isolation converter for each battery port, this significantly reduces the number of power switching transistors, drive circuits, and magnetic components. This not only effectively improves the system's power density but also reduces hardware costs. The dual phase-shift control strategy proposed in this invention, based on achieving stable DC bus voltage and bidirectional energy flow, dynamically optimizes the charging and discharging current of the two battery ports based on their real-time status (such as internal resistance, SOC, and health) through independent closed-loop control of the current. When connected to battery packs with different performance characteristics, this strategy enables intelligent on-demand power allocation, allowing higher-performance, lower-resistance battery packs to handle more power output. This optimizes energy output efficiency at the system level, effectively extends the overall lifespan of the battery pack, and reduces the total lifespan cost. The technology of this invention helps energy storage equipment in new power systems achieve high power density, promotes the greening process of new power grids with high proportions of new energy applications in my country, and helps products using this technology gain market share and bring significant economic benefits.

[0068] A specific embodiment of the present invention is as follows:

[0069] use Figure 1 The circuit topology diagram shown and Figure 2 The controller shown is used to build a bidirectional DC / DC converter in the energy storage system to achieve bidirectional energy flow between the energy storage battery and the bus, such as Figure 3 As shown, the high-voltage side of the three-port dual-channel dual active bridge circuit 1 is connected to the bidirectional AC / DC converter 7 on the grid side, and then the bidirectional AC / DC converter 7 on the grid side is connected to the power grid, thus forming a bidirectional energy storage system. Figure 3 The rated power of the bidirectional energy storage system is 8 kW, wherein the battery pack voltage V connected to the battery side of the three-port dual-channel dual active bridge circuit is... bat1 and V bat2 The range is 40V~60V, DC bus voltage V bus= 400V, the rated power of each channel is 4kW, and the maximum charge and discharge battery current is 100A; the rated value and frequency of the grid-side AC voltage are 230V / 50Hz; MOSFET field effect transistors are selected in the first dual active bridge circuit 5 and the second dual active bridge circuit 6, and the battery-side switching transistors Q1~Q8 are N-channel MOSFET transistors produced by CRMICRO (China Resources Microelectronics) with the model number CRSQ027N10N (rated drain-source voltage 100V, rated current 180A), and the high-voltage side switching transistors Q9~Q 12 Select N-channel MOSFET transistors produced by onsemi (ON Semiconductor) with the model number FCH072N60 (rated voltage 600V, rated current 52A), and the switching frequency is 40kHz, Figure 1 and Figure 3 D1~D 12 and C1~C 12 are the body diodes and junction capacitances of the switching transistors Q1~Q 12 ; the high-frequency transformers T r1 and T r2 select EE65 magnetic cores, and the turn ratio of the battery-side winding to the high-voltage side winding is 1:8.

[0070] According to the switching frequency and transmission power, the resonant inductor L s = 15 can be calculated, and the DC-blocking capacitor C b = 26 ; the grid-side bidirectional AC / DC converter 7 adopts a single-phase H6 full-bridge circuit. When the battery pack discharges through the three-port two-channel dual active bridge circuit 1, the energy is transmitted to the DC bus to establish the DC bus voltage V bus . The energy of the DC bus is converted into 230V / 50HZ alternating current by the grid-side bidirectional AC / DC converter 7 and transmitted to the power grid or load; when the battery pack is charged through the three-port two-channel dual active bridge circuit 1, the grid-side bidirectional AC / DC converter 7 first absorbs AC power from the power grid, and then rectifies it into direct current to establish and maintain the DC bus voltage. This DC energy then passes through the three-port two-channel dual active bridge circuit 1 to charge the battery pack on the battery side. Figure 3 The closed-loop controller of the three-voltage outer loop and two-current inner loop and the internal phase-shift controller in it are implemented by the digital chip TMS320F28035 of TI (Texas Instruments) company;

[0071] Figure 3When the energy storage system shown is charging the battery pack, the battery charging voltage outer loop of the first dual active bridge circuit 5, the battery charging voltage outer loop of the second dual active bridge circuit 6, the current inner loop of the first dual active bridge circuit 5 and the current inner loop of the second dual active bridge circuit 6, the first battery-side voltage regulator and the second battery-side voltage regulator in the closed-loop controller 2 with three voltage outer loops and two current inner loops are activated. Their outputs are selected by the selector switch, and the constant voltage charging reference voltage V of the first battery pack on the battery side is activated. bat_ref1 The battery voltage sampling value V of the first battery pack on the battery side bat1 The error is generated by the first battery-side voltage regulator, which generates the battery current given by the first dual active bridge circuit 5. bat1_ref The constant voltage charging reference voltage V of the second battery pack on the battery side. bat_ref2 The battery voltage sampling value V of battery 2 on the battery side bat2 The error is generated by the second battery-side voltage regulator, which generates the battery current given by the second dual active bridge circuit 6. bat2_ref Thus, respectively compared with the corresponding battery current sampling value I bat1 and I bat2 Errors are generated by the battery-side current regulators 1 and 2 in their respective inner current loops, producing phase shift angles Φ1 and Φ2. These phase shift angles are then processed by their respective phase shift controllers 1 and 2, as shown below. Figure 4 The phase-shifting pulse control signal 1 and phase-shifting pulse control signal 2 shown are then used by the drive circuit 3 to generate the corresponding drive signals for the switching transistors. Figure 4 The given phase-shifting pulse control signals are the on / off timing sequences of the switching transistors in the invention circuit. Phase-shifting pulse control signal 1 provides the control signals for the corresponding switching transistors of the battery-side full-bridge and high-voltage-side full-bridge in the first dual active bridge circuit 5, while phase-shifting pulse control signal 2 provides the control signals for the corresponding switching transistors of the battery-side full-bridge and high-voltage-side full-bridge in the second dual active bridge circuit 6. Figure 4 When battery 1 is charging, the switching of the battery-side full-bridge circuit switch in the first dual active bridge circuit 5 in phase-shift pulse control signal 1 lags behind the corresponding high-voltage side full-bridge switch by phase angle Φ1. When battery 2 is discharging, the switching of the battery-side full-bridge circuit switch in the second dual active bridge circuit 6 in phase-shift pulse control signal 2 lags behind the corresponding high-voltage side full-bridge switch by phase angle Φ2. If the SOC of the second battery pack connected to the battery side of the second dual active bridge circuit 6 is greater than the SOC of the first battery pack connected to the battery side of the first dual active bridge circuit 5, then the phase shift angle Φ2 > Φ1, which means that the charging current through the first dual active bridge circuit 5 will be smaller.

[0072] Figure 3 When the energy storage system shown is charging the battery pack, the first internal phase shift regulator, the second internal phase shift regulator, the phase shift controller 3, and the phase shift controller 4 in the internal phase shift controller 4 operate: the high-voltage side bus voltage sampling value V busThe battery pack voltage sampling value V of the first dual active bridge circuit bat1 The sampled value V of the high-voltage side bus voltage is fed into the first internal phase shift regulator, which generates an internal shift angle δ1. bus The battery pack voltage sampling value V of the second dual active bridge circuit bat2 The signal is fed into the second internal phase shift regulator, which generates an internal shift angle δ2. The generated phase shift angles δ1 and δ2 are then processed by their respective phase shift controllers 3 and 4 to produce the following... Figure 3 The third phase-shift pulse control signal and phase-shift pulse control signal 4, as shown, are then used by the drive circuit 3 to generate corresponding switching angle signals. The third phase-shift pulse control signal controls the angle between the diagonal switching transistors of the battery-side full bridge in the first dual active bridge circuit 5, while the phase-shift pulse control signal 4 controls the angle between the diagonal switching transistors of the battery-side full bridge in the second dual active bridge circuit 6. If the voltage of the first battery pack connected to the battery side of the first dual active bridge circuit 5 is 40V, and the voltage of the second battery pack connected to the battery side of the second dual active bridge circuit 6 is 60V, the voltage supplied to the primary side of the high-frequency transformer and the voltage output from the secondary side do not match the transformer's turns ratio, resulting in a large amount of reactive circulating current. By adjusting the internal shift angles δ1 and δ2, the voltage supplied to the high-frequency transformer T by the first and second dual active bridge circuits is adjusted. r1 and T r2 The voltage of the windings is adjusted to achieve the transformation of the voltage between the primary and secondary windings of the high-frequency transformer, which matches the turns ratio of the high-frequency transformer, reduces reactive backflow in the system, enables soft switching across the entire range, and improves system efficiency.

[0073] Figure 3 The DC terminals of the battery-side full-bridge circuit of the first dual active bridge circuit and the battery-side full-bridge circuit of the second dual active bridge circuit form a dual-channel port for connecting battery packs of different performance. These different performance batteries can be represented as follows: lithium battery 1 with a voltage of 60V is connected to the battery side of the first dual active bridge circuit, and lithium battery 2 with a voltage of 55V is connected to the battery side of the second dual active bridge circuit. The charging waveform of lithium battery 1 is as follows: Figure 6 and Figure 8 The charging waveform of lithium battery 2 is as follows Figure 7 and Figure 9 As shown, Figure 6 In the diagram, CH1 is the current of battery 1, CH2 is the bus voltage, and CH3 is the voltage of battery 1. Figure 8 CH1 is the drive signal for battery-side switch Q1, CH2 is the drive signal for battery-side switch Q4, CH3 is the drive signal for high-voltage-side switch Q9, and CH4 is the drive signal for high-voltage-side switch Q1. 12 Drive signal; Figure 7 In this context, CH1 is the voltage of battery 2, CH2 is the bus voltage, and CH3 is the current of battery 2. Figure 9CH1 is the drive signal for battery-side switch Q5, CH2 is the drive signal for battery-side switch Q8, CH3 is the drive signal for high-voltage-side switch Q9, and CH4 is the drive signal for high-voltage-side switch Q9. 12 Drive signal; by Figure 6 and Figure 8 It is known that the inward shift angle of the battery side of the first dual active bridge is relatively large, the charging current of battery 1 is 50.4A, and the charging power is approximately 25% (50A / 200A), which is consistent with the performance of the 60V battery 1 configuration; Figure 7 and Figure 9 The second dual active bridge has a smaller inward shift angle on the battery side, and the charging current of battery 2 is 26.6A, with a charging power of approximately 12.5% ​​(25A / 200A), which is consistent with the performance of the 55V battery 2 configuration.

[0074] Figure 3 When the energy storage system shown needs battery discharge, the bus voltage outer loop, the first dual active bridge circuit 5's current inner loop, and the second dual active bridge circuit 6's current inner loop in the closed-loop controller 2 (three voltage outer loops and two current inner loops) operate. At this time, the output of the high-voltage side voltage regulator is selected by the selector switch, based on the high-voltage side bus voltage sampling value V. bus With high voltage side bus reference voltage V bus_ref The error obtained by subtraction is used by the high-voltage side voltage regulator to generate the battery current command I. bat_ref The current command I of the first dual active bridge circuit is then output through the current command distributor. bat1_ref The current given I of the second dual active bridge circuit bat2_ref Thus, respectively compared with the corresponding battery current sampling value I bat1 and I bat2 Errors are generated by the battery-side current regulators 1 and 2 in their respective inner current loops, producing phase shift angles Φ1 and Φ2. These phase shift angles are then used by their respective phase shift controllers 1 and 2 to generate phase shift pulse control signals 1 and 2, which in turn generate drive signals for the corresponding switching transistors via the drive circuit 3. The operation of the first inner phase shift regulator, the second inner phase shift regulator, the phase shift controller 3, and the phase shift controller 4 within the inner phase shift controller 4 is as follows: The high-voltage side bus voltage sampling value V... bus The battery pack voltage sampling value V of the first dual active bridge circuit bat1 The sampled value V of the high-voltage side bus voltage is fed into the first internal phase shift regulator, which generates an internal shift angle δ1. bus The battery pack voltage sampling value V of the second dual active bridge circuit bat2 The signal is fed into the second internal phase shift regulator, which generates an internal shift angle δ2. The generated phase shift angles δ1 and δ2 are then processed by their respective phase shift controllers 3 and 4 to produce the following... Figure 3The third phase-shifting pulse control signal and phase-shifting pulse control signal 4 shown are then used by the drive circuit 3 to generate corresponding switching transistor signals. The third phase-shifting pulse control signal controls the angle between the diagonal switching transistors of the battery-side full bridge in the first dual active bridge circuit 5, while the phase-shifting pulse control signal 4 controls the angle between the diagonal switching transistors of the battery-side full bridge in the second dual active bridge circuit 6. Figure 10 The given phase-shifting pulse control signals are used by the invented circuit and control method to implement the switching timing of the switching transistors during battery discharge. Phase-shifting pulse control signal 1 provides the control signals for the corresponding switching transistors of the battery-side full bridge and high-voltage-side full bridge of the first dual active bridge circuit 5, while phase-shifting pulse control signal 2 provides the control signals for the corresponding switching transistors of the battery-side full bridge and high-voltage-side full bridge of the second dual active bridge circuit 6. Figure 9 When the first battery pack discharges, the switching of the battery-side full-bridge circuit switch in the first dual active bridge circuit 5 in phase-shift pulse control signal 1 leads the corresponding high-voltage side full-bridge switch by phase angle Φ1. When the second battery pack discharges, the switching of the battery-side full-bridge circuit switch in the second dual active bridge circuit 6 in phase-shift pulse control signal 2 leads the corresponding high-voltage side full-bridge switch by phase angle Φ2. If the SOC of battery 2 connected to the battery side of the second dual active bridge circuit 6 is greater than the SOC of battery 1 connected to the battery side of the first dual active bridge circuit 5, then the phase shift angle Φ1 < Φ2, which means that the discharge current through the second dual active bridge circuit 6 will be larger.

[0075] In the discharge experiment, lithium battery 1 with a voltage of 60V was connected to the battery side of the first dual active bridge circuit, and lithium battery 2 with a voltage of 55V was connected to the battery side of the second dual active bridge circuit. The discharge waveform of lithium battery 1 is as follows. Figure 11 and Figure 13 The discharge waveform of lithium battery 2 is as follows Figure 12 and Figure 14 As shown, Figure 11 In the diagram, CH1 is the voltage of battery 1, CH2 is the bus voltage, and CH3 is the current of battery 1. Figure 13 CH1 in the code is the drive signal for the high-voltage side switch Q9, and CH2 is the drive signal for the high-voltage side switch Q. 12 The drive signals are CH3 and CH4. CH3 is the drive signal for battery-side switch Q1 and CH4 is the drive signal for battery-side switch Q4. Figure 12 In this context, CH1 is the voltage of battery 2, CH2 is the bus voltage, and CH3 is the current of battery 2. Figure 13 CH1 is the drive signal for battery-side switch Q5, CH2 is the drive signal for battery-side switch Q8, CH3 is the drive signal for high-voltage-side switch Q9, and CH4 is the drive signal for high-voltage-side switch Q9. 12 Drive signal; by Figure 11 and Figure 13It is known that the inward shift angle of the battery side of the first dual active bridge is relatively large. The discharge current of battery 1 is 25A, and the discharge power is approximately 12.5% ​​(25A / 200A), which is consistent with the performance of the 60V battery 1 configuration; Figure 12 and Figure 14 The second dual active bridge has a smaller inward shift angle on the battery side, and the discharge current of battery 2 is 15A, with a discharge power of approximately 7.5% (15A / 200A), which is consistent with the performance of the 55V battery 2 configuration.

[0076] As can be seen from the above description, the dual phase-shifting method of the invented three-port dual-channel dual active bridge circuit has the following advantages:

[0077] (1) The present invention can simultaneously connect two sets of battery packs with different performance and realize bidirectional energy transmission between the battery pack and the bus;

[0078] (2) This invention integrates multiple ports through a single multi-winding transformer, which significantly reduces the number of power switching devices and magnetic components. With the help of internal and external phase shift control strategies, it can achieve soft switching operation over a wide load range. The system has high efficiency, high power density and high reliability, which helps to reduce the overall system cost and improve battery life.

[0079] (3) The solution provided by the present invention is applicable to various bidirectional energy storage systems and can be applied to scenarios such as bidirectional charging piles for electric vehicles, thereby supporting multiple energy interaction modes such as vehicle-to-grid and vehicle-to-home.

[0080] (4) Based on the same design concept, the structure can be further extended into a converter with multiple low-voltage side ports to connect more battery cells with different performance, thereby further optimizing system cost and energy management flexibility in large-scale energy storage systems.

[0081] The above description of the embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A three-port dual-channel dual active bridge circuit, characterized in that, include: The circuit consists of a first battery-side dual active bridge full-bridge circuit, a second battery-side dual active bridge full-bridge circuit, and a high-voltage-side dual active bridge full-bridge circuit. The DC input ports of the first battery-side dual active bridge full-bridge circuit and the second battery-side dual active bridge full-bridge circuit are respectively connected to the first battery pack and the second battery pack. The midpoint of the bridge arm of the first battery-side dual active bridge full-bridge circuit and the midpoint of the bridge arm of the second battery-side dual active bridge full-bridge circuit are connected to the corresponding high-frequency transformer T. r1 and T r2 Primary winding; the high-frequency transformer consists of two T-type windings. r1 T r2 It is made by winding a primary winding and a secondary winding; One end of the secondary winding of the high-frequency transformer is connected to the resonant inductor L. s The resonant inductor L is connected in series. s With DC blocking capacitor C b The DC blocking capacitor C is connected in series. b The high-voltage side dual active bridge full-bridge circuit is connected in series with the midpoint of the bridge arm, and the midpoint of the other bridge arm of the high-voltage side dual active bridge full-bridge circuit is connected to the other end of the secondary winding of the high-frequency transformer. The DC output port of the high-voltage side dual active bridge full-bridge circuit is connected to the high-voltage DC bus.

2. A dual phase-shift control method for a three-port dual-channel dual active bridge circuit as described in claim 1, characterized in that, include: Step 1) Control the outward shift angle using a closed-loop controller with three voltage outer loops and two current inner loops; 1-1) The voltage error signals of each battery pack and bus are combined to form the total current command, which is then decomposed by the distributor and output to the dual active bridge circuits on both sides as current commands. 1-2) The first dual active bridge circuit compares the current setpoint with the sampled value, generates an external phase shift angle through the regulator, and drives the switching transistor through PWM modulation, thus forming the current inner loop closed-loop control of the first dual active bridge circuit. 1-3) The second dual active bridge circuit compares the current setpoint with the sampled value, generates an external phase shift angle through the regulator, and drives the switching transistor through PWM modulation, thus forming the current inner loop closed-loop control of the second dual active bridge circuit. 1-4) When the mode selection switch selects the battery-side voltage regulator, the two dual active bridge circuits charge the corresponding battery packs respectively, and form the charging voltage outer loop by comparing the battery voltage sampling value with the reference voltage. 1-5) When the mode selection switch selects the high-voltage side voltage regulator, the two battery packs discharge to power the bus. The bus voltage outer loop is formed by comparing the bus voltage sample value with the reference voltage. 1-5) The three voltage outer loops and the two current inner loops together constitute a closed-loop controller for a three-port dual-channel dual active bridge circuit, which controls the magnitude and direction of energy transfer by adjusting the outer shift angle; Step 2) Control the inward shift angle using the inward shift controller; 2-1) The bus voltage and the voltage of each battery pack are respectively sent to the corresponding internal phase shift regulator to generate an internal shift angle, and then the phase shift angle between the same side switches in the two dual active bridge circuits is controlled by the phase shift control and drive circuit. 2-2) The internal phase shift regulator and the phase shift controller constitute the internal angle shift controller, which controls the power distribution ratio between the primary and secondary sides of the transformer by adjusting the phase shift angle of the same-side switching transistors of the dual active bridge circuits on both sides.

3. The dual phase-shift control method for a three-port dual-channel dual active bridge circuit according to claim 2, characterized in that, Step 1-1) specifically includes: the constant voltage charging reference voltage V of the first battery pack on the battery side. bat_ref1 The voltage sampling value V of the first battery pack on the battery side bat1 The subtraction generates the first battery voltage error signal; the constant voltage charging reference voltage V of the second battery pack on the battery side. bat_ref2 The voltage sampling value V of the second battery pack on the battery side bat2 The subtraction generates a second battery voltage error signal; the high-voltage side bus reference voltage V bus_ref With high voltage side bus voltage V bus The subtraction generates a bus voltage error signal; the first battery voltage error signal, the second battery voltage error signal, and the bus voltage error signal are used as the battery current reference, and then the current reference of the first battery side dual active bridge circuit and the second battery side dual active bridge circuit are output through the current reference distributor.

4. The dual phase-shift control method for a three-port dual-channel dual active bridge circuit according to claim 3, characterized in that, Steps 1-2) specifically include: the current setpoint of the first battery-side dual active bridge circuit is subtracted from the battery current sample value of the dual active bridge circuit of the first battery pack on the battery side, and then sent to the first current regulator on the battery side. The first current regulator on the battery side generates an outer shift angle Φ1. The outer shift angle Φ1 and the first triangular carrier wave are used to generate a first outer phase shift pulse control signal through a phase shift controller. The first outer phase shift pulse control signal generates a corresponding drive signal through a drive circuit to control the switching of the switching transistor in the first dual active bridge circuit, thereby generating the battery current of the first dual active bridge circuit and forming the battery current sample value of the first dual active bridge circuit. The battery current sample value of the first dual active bridge circuit is sent to be subtracted from the current setpoint of the first dual active bridge circuit to form the current inner loop of the first dual active bridge circuit.

5. The dual phase-shift control method for a three-port dual-channel dual active bridge circuit according to claim 4, characterized in that, Steps 1-3) specifically include: the current setpoint of the second battery-side dual active bridge circuit is subtracted from the battery current sample value of the dual active bridge circuit of the second battery pack on the battery side, and then sent to the second current regulator on the battery side. The second current regulator on the battery side generates an outer shift angle Φ2. The outer shift angle Φ2 and the second triangular carrier are used to generate a second outer phase shift pulse control signal through a phase shift controller. The second outer phase shift pulse control signal generates a corresponding drive signal through a drive circuit to control the switching of the switching transistor in the second dual active bridge circuit, thereby generating the battery current of the second dual active bridge circuit and forming the battery current sample value of the second dual active bridge circuit. The battery current sample value of the second dual active bridge circuit is sent to be subtracted from the current setpoint of the second dual active bridge circuit to form the current inner loop of the second dual active bridge circuit.

6. The dual phase-shift control method for a three-port dual-channel dual active bridge circuit according to claim 5, characterized in that, Steps 1-4) specifically include: If the outputs of the first battery-side voltage regulator and the second battery-side voltage regulator are selected by the mode selection switch, then the battery current of the first dual active bridge circuit charges the battery pack in the first dual active bridge circuit, generating the battery-side battery voltage of the first dual active bridge circuit and forming the battery-side battery pack voltage sampling value V of the first dual active bridge circuit. bat1 The battery pack voltage sampling value V on the battery side of the first dual active bridge circuit. bat1 Send a constant voltage charging reference voltage V to the first battery pack on the battery side. bat_ref1 Subtracting these values ​​creates the outer loop of the battery charging voltage for the first dual active bridge circuit; the battery current in the second dual active bridge circuit charges the battery pack within the second dual active bridge circuit, generating the battery-side voltage of the second dual active bridge circuit and forming the sampled voltage value V of the second battery pack on the battery side of the second dual active bridge circuit. bat2 The battery pack voltage sampling value V on the battery side of the second dual active bridge circuit. bat2 Sending a constant voltage charging reference voltage V to the second battery on the battery side bat_ref2 Subtracting these values ​​creates the outer loop of the battery charging voltage in the second dual active bridge circuit.

7. The dual phase-shift control method for a three-port dual-channel dual active bridge circuit according to claim 6, characterized in that, Steps 1-5) specifically include: If the output of the high-voltage side voltage regulator is selected by the mode selection switch, then both the battery packs of the first dual active bridge circuit and the battery packs of the second dual active bridge circuit discharge to provide energy to the bus, generating the high-voltage side bus voltage and forming the high-voltage side bus voltage sampling value V. bus The sampled value of the high-voltage side bus voltage is sent to be subtracted from the reference voltage of the high-voltage side bus, thereby forming the outer loop of the bus voltage.

8. The dual phase-shift control method for a three-port dual-channel dual active bridge circuit according to claim 7, characterized in that, Steps 1-6) specifically include: the inner current loop of the first dual active bridge circuit and the inner current loop of the second dual active bridge circuit constitute the two inner current loops, and the outer battery charging voltage loop of the first dual active bridge circuit, the outer battery charging voltage loop of the second dual active bridge circuit, and the outer bus voltage loop constitute the three outer voltage loops, forming a closed-loop controller of three voltage outer loops and two inner current loops of the three-port dual-channel dual active bridge circuit. By controlling the outward shift angle between the switching transistors of the battery side circuit and the switching transistors of the bus side circuit of the first and second dual active bridge circuits, the magnitude and direction of energy transfer between the battery side and the bus side are controlled.

9. The dual phase-shift control method for a three-port dual-channel dual active bridge circuit according to claim 8, characterized in that, Step 2-1) specifically includes: in the inner angle controller, the high-voltage side bus voltage sampling value V bus First battery pack voltage sampling value V bat1 The signal is fed into the first internal phase-shift regulator, which generates an internal shift angle δ1. The internal shift angle δ1 and the third triangular carrier phase-shift controller generate a third phase-shift pulse control signal. This third phase-shift pulse control signal is then used by the drive circuit to generate a corresponding drive signal to control the angle difference between the same-side switching transistors in the first dual active bridge circuit. The high-voltage side bus voltage sampling value V... bus Second battery pack voltage sampling value V bat2 The signal is fed into the second inner phase shift regulator, which generates an inner shift angle δ2. The inner shift angle δ2 and the fourth triangular carrier phase shift controller generate a fourth phase shift pulse control signal. The fourth phase shift pulse control signal is driven by the drive circuit to generate a corresponding drive signal to control the angle difference between the same-side switching transistors in the second dual active bridge circuit.

10. The dual phase-shift control method for a three-port dual-channel dual active bridge circuit according to claim 9, characterized in that, Step 2-2) specifically includes: the first internal phase shifter, the second internal phase shifter, the third phase shifter and the fourth phase shifter constitute the internal angle shifter controller, which controls the angle between the switching transistors of the same side circuits of the first and second dual active bridge batteries, thereby controlling the power distribution ratio between the two full bridges on the primary and secondary sides of the transformer.

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