A three-phase dual active bridge converter adaptive hybrid modulation method and system based on partition optimization

Abstract

The application discloses a three-phase dual active bridge converter adaptive hybrid modulation method and system based on partition optimization, first, the load range of the three-phase dual active bridge converter is dynamically divided into a light load area, a medium load area and a heavy load area based on a load rate, then a steady-state response hysteresis control strategy is constructed for the light load area, the medium load area and the heavy load area in combination with a voltage transfer ratio and a load change rate; the application realizes the function of partition optimization of different targets by adopting the light load, medium load and heavy load area division based on the load rate in combination with the adaptive selection of the modulation strategy of the voltage transfer ratio K and the load change rate, and the light load, medium load and heavy load area respectively adopts PFM dominant modulation, PSM plus dynamic PDM three-degree-of-freedom control and PSM dominant modulation, so that the full-condition efficiency optimization and transient performance improvement can be realized under a wide voltage range and a dynamic load, and the application is suitable for being widely promoted and used.

Description

Technical Field

[0001] This invention relates to the field of power electronic converter control technology, specifically to an adaptive hybrid modulation method and system for a three-phase dual active bridge converter based on partition optimization. Background Technology

[0002] The three-phase dual active bridge converter is a typical representative and important solution for the development of modern power electronics technology towards higher frequency, higher efficiency, and higher power density, playing a crucial role, especially in the fields of new energy vehicles and renewable energy. Due to its electrical isolation, bidirectional power flow, and soft-switching characteristics, the three-phase dual active bridge converter has become a core device for DC-DC power conversion, but its performance is highly dependent on the modulation strategy.

[0003] Currently, existing single-phase-shift modulation SPS generally tends to generate high return current power under light load conditions, leading to a sharp increase in current stress. Furthermore, due to its low efficiency under light load, it is prone to DC bus voltage oscillation during load changes. At the same time, load changes can also cause imbalance in the three-phase inductor current, making it difficult to adapt to dynamic loads. Therefore, it is necessary to design an adaptive hybrid modulation method and system for a three-phase dual active bridge converter based on partition optimization. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and to better and more effectively solve the problems of existing single-phase-shift modulation (SPS) converters, which generally generate high return power under light load conditions, leading to a surge in current stress, and low efficiency under light load conditions, making them prone to DC bus voltage oscillations during load changes. Furthermore, load changes can also cause three-phase inductor current imbalance, making them difficult to adapt to dynamic loads. This invention provides an adaptive hybrid modulation method and system for a three-phase dual active bridge converter based on partitioned optimization. It achieves the function of partitioning light load, medium load, and heavy load regions based on load rate and adaptively selecting modulation strategies based on voltage transfer ratio K and load change rate to optimize different objectives. Moreover, it employs PFM-dominated modulation, PSM plus dynamic PDM three-degree-of-freedom control, and PSM-dominated modulation respectively for the light load, medium load, and heavy load regions, achieving full-condition efficiency optimization and transient performance improvement under a wide voltage range and dynamic load.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] An adaptive hybrid modulation method for a three-phase dual active bridge converter based on partition optimization includes the following steps:

[0007] Step A: Based on the load rate, the load range of the three-phase dual active bridge converter is dynamically divided into light load, medium load and heavy load regions. Then, combined with the voltage transfer ratio and load change rate, a steady-state response switching hysteresis control strategy is constructed for the light load, medium load and heavy load regions.

[0008] Step B: Construct a transient response switching control strategy for the three-phase dual active bridge converter based on the voltage transfer ratio and load change rate;

[0009] Step C: Establish an anti-three-phase imbalance mechanism for the three-phase dual active bridge converter;

[0010] Step D involves using a steady-state response switching hysteresis control strategy, a transient response switching control strategy, and an anti-three-phase imbalance mechanism to complete the adaptive hybrid modulation operation of the three-phase dual active bridge converter.

[0011] The aforementioned adaptive hybrid modulation method for a three-phase dual active bridge converter based on partition optimization includes step A, which involves dynamically dividing the load range of the three-phase dual active bridge converter into light load, medium load, and heavy load regions based on the load rate. Then, combining the voltage transfer ratio and load change rate, a steady-state response switching hysteresis control strategy is constructed for the light load, medium load, and heavy load regions. The specific steps are as follows.

[0012] Step A1: Based on the load rate, the load range of the three-phase dual active bridge converter is dynamically divided into a light load zone, a medium load zone, and a heavy load zone according to the partition threshold. The load rate β threshold of the light load zone is less than 30%, the load rate β threshold of the medium load zone is not less than 30% and not greater than 80%, and the load rate β threshold of the heavy load zone is greater than 80%.

[0013] Step A2: Combine voltage transfer ratio and load change rate to construct steady-state response switching hysteresis control strategy for light load region, medium load region and heavy load region. Specifically, in the light load region, minimizing circulating current loss is taken as the modulation target and PFM-dominated modulation is adopted.

[0014] The intermediate load region specifically uses minimizing current stress as the modulation target and employs PSM plus dynamic PDM three-degree-of-freedom control.

[0015] The heavy-load region specifically aims to maximize transmission efficiency and reduce control complexity, and adopts PSM-dominated modulation.

[0016] The aforementioned adaptive hybrid modulation method for a three-phase dual active bridge converter based on partition optimization, wherein the partition threshold in step A1 is adaptively adjusted using an adaptive adjustment method based on leakage inductance temperature drift, as shown in formula (1).

[0017] (1)

[0018] in, For dynamic partitioning thresholds, As the baseline partition threshold, This represents the change in temperature drift due to leakage sensing. This is the baseline leakage inductance value.

[0019] The aforementioned adaptive hybrid modulation method for a three-phase dual active bridge converter based on partition optimization, specifically the PFM-dominated modulation in step A2, involves setting the frequency modulation range. Then, the ZVS range is extended to 95% of the switching cycle and the frequency modulation range is limited by frequency hopping, as shown in formula (2).

[0020] (2)

[0021] in, This is the rated switching frequency.

[0022] The aforementioned adaptive hybrid modulation method for a three-phase dual active bridge converter based on partition optimization, specifically the PSM plus dynamic PDM three-degree-of-freedom control in step A2, involves constructing a real-time optimization model and using an adaptive PSO algorithm to solve for the optimal solution set in real time. The specific steps are as follows.

[0023] Step A21: Construct the optimization objective function, as shown in formula (3).

[0024] (3)

[0025] in, This is the effective value of the inductor current. Compared to bridge-to-bridge movement, This represents the duty cycle of the original edge. For the secondary side duty cycle, For the switching cycle, This refers to the instantaneous inductor current;

[0026] Step A22: Construct the ZVS boundary conditions for the objective function, as shown in formula (4).

[0027] (4)

[0028] in, For the shutdown time, For the output capacitor of the switching transistor, Input voltage, This refers to the dead zone time.

[0029] The aforementioned adaptive hybrid modulation method for a three-phase dual active bridge converter based on partition optimization, specifically employing PSM-dominated modulation in step A2, involves using inter-bridge phase shifting. Single degree of freedom control reduces computational complexity.

[0030] The aforementioned adaptive hybrid modulation method for a three-phase dual active bridge converter based on partition optimization, step B, involves constructing a transient response switching control strategy for the three-phase dual active bridge converter based on the voltage transfer ratio and load change rate. The specific steps are as follows.

[0031] Step B1, calculate the voltage transfer ratio As shown in formula (5),

[0032] (5)

[0033] in, This is the effective value of the input voltage. This is the effective value of the output voltage;

[0034] Step B2, calculate the load change rate. As shown in formula (6),

[0035] (6);

[0036] Step B3, when At this time, due to voltage mismatch, forced intervention is implemented and a three-degree-of-freedom control mode of PSM plus dynamic PDM is adopted to suppress backflow power;

[0037] Step B4, when At this time, due to a sudden load change, forced intervention and the adoption of PFM control mode are used to accelerate the transient response.

[0038] The aforementioned adaptive hybrid modulation method for a three-phase dual active bridge converter based on partition optimization, step C, involves establishing an anti-three-phase imbalance mechanism for the three-phase dual active bridge converter. The specific steps are as follows:

[0039] Step C1: Implement closed-loop current balancing control and calculate the three-phase current imbalance in real time. As shown in formula (7),

[0040] (7)

[0041] in, , and For each phase inductor current, Average current;

[0042] Step C2: If the three-phase current imbalance δ > 10%, adjust the secondary duty cycle according to phase. As shown in formula (8),

[0043] (8)

[0044] in, To correct the duty cycle, The original duty cycle, This is the proportionality coefficient. Reference current;

[0045] Step C3 involves using space vector decoupling to eliminate interphase coupling effects, and then inserting a voltage equalization control sequence during the transient period to suppress DC bias current, thereby ensuring volt-second balance.

[0046] An adaptive hybrid modulation system for a three-phase dual active bridge converter based on partition optimization includes a steady-state response switching hysteresis control module, a transient response switching control module, an anti-three-phase imbalance module, and an adaptive hybrid modulation module. The steady-state response switching hysteresis control module dynamically divides the load range of the three-phase dual active bridge converter into light-load, medium-load, and heavy-load regions based on the load rate, and then constructs a steady-state response switching hysteresis control strategy for each region based on the voltage transfer ratio and load change rate. The transient response switching control module constructs a transient response switching control strategy for the three-phase dual active bridge converter based on the voltage transfer ratio and load change rate. The anti-three-phase imbalance module establishes an anti-three-phase imbalance mechanism for the three-phase dual active bridge converter. The adaptive hybrid modulation module utilizes the steady-state response switching hysteresis control strategy, the transient response switching control strategy, and the anti-three-phase imbalance mechanism to complete the adaptive hybrid modulation operation of the three-phase dual active bridge converter.

[0047] The beneficial effects of this invention are as follows: The adaptive hybrid modulation method and system for a three-phase dual active bridge converter based on partition optimization first dynamically divides the load range of the three-phase dual active bridge converter into light load, medium load, and heavy load regions based on the load rate. Then, combining the voltage transfer ratio and load change rate, a steady-state response switching hysteresis control strategy is constructed for the light load, medium load, and heavy load regions. Next, a transient response switching control strategy is constructed for the three-phase dual active bridge converter based on the voltage transfer ratio and load change rate. Subsequently, an anti-three-phase imbalance mechanism is established for the three-phase dual active bridge converter. Finally, the adaptive hybrid modulation operation of the three-phase dual active bridge converter is completed using the steady-state response switching hysteresis control strategy, the transient response switching control strategy, and the anti-three-phase imbalance mechanism. This effectively realizes the adaptive hybrid modulation operation of the three-phase dual active bridge converter. The adaptive hybrid modulation method and system have the function of dividing light load, medium load and heavy load regions based on load rate and combining voltage transmission ratio K and load change rate to adaptively select modulation strategy to optimize different objectives. Furthermore, PFM-dominated modulation, PSM plus dynamic PDM three-degree-of-freedom control and PSM-dominated modulation are respectively used for light load, medium load and heavy load regions to achieve full-condition efficiency optimization and transient performance improvement under wide voltage range and dynamic load. The set steady-state response switching hysteresis control strategy and transient response switching control strategy can suppress backflow power and accelerate transient response. At the same time, the set anti-three-phase imbalance mechanism can not only eliminate inter-phase coupling effect by using space vector decoupling, but also insert voltage equalization control sequence during transient period to suppress DC bias current and ensure volt-second balance. Attached Figure Description

[0048] Figure 1 This is an overall flowchart of an adaptive hybrid modulation method for a three-phase dual active bridge converter based on partition optimization according to the present invention.

[0049] Figure 2 This is a schematic diagram illustrating the operating principle of an adaptive hybrid modulation system based on partition optimization of a three-phase dual active bridge converter according to the present invention.

[0050] Figure 3 This is a comparison chart of the modulation efficiency of the present invention with that of existing SPS in an embodiment of the present invention;

[0051] Figure 4 This is a comparison diagram of the stress of the current modulated by SPS in an embodiment of the present invention with that of the existing SPS modulation.

[0052] Figure 5 This is a comparison diagram of the three-phase imbalance of the present invention with that of existing SPS modulation in an embodiment of the present invention. Detailed Implementation

[0053] The present invention will now be further described with reference to the accompanying drawings.

[0054] like Figure 1 As shown, the present invention provides an adaptive hybrid modulation method for a three-phase dual active bridge converter based on partition optimization, comprising the following steps:

[0055] Step A involves dynamically dividing the load range of the three-phase dual active bridge converter into light load, medium load, and heavy load regions based on the load rate. Then, combining the voltage transfer ratio and load change rate, a steady-state response switching hysteresis control strategy is constructed for each of the light load, medium load, and heavy load regions. The specific steps are as follows.

[0056] Step A1: Based on the load rate, the load range of the three-phase dual active bridge converter is dynamically divided into a light load zone, a medium load zone, and a heavy load zone according to the partition threshold. The load rate β threshold of the light load zone is less than 30%, the load rate β threshold of the medium load zone is not less than 30% and not greater than 80%, and the load rate β threshold of the heavy load zone is greater than 80%. The partition threshold is adaptively adjusted using an adaptive adjustment method based on leakage sensing temperature drift, as shown in formula (1).

[0057] (1)

[0058] in, For dynamic partitioning thresholds, As the baseline partition threshold, This represents the change in temperature drift due to leakage sensing. This is the baseline leakage inductance value.

[0059] Step A2 involves constructing a steady-state response switching hysteresis control strategy for the light-load, medium-load, and heavy-load regions by combining the voltage transfer ratio and load change rate. Specifically, in the light-load region, minimizing circulating current loss is used as the modulation target, and PFM-dominated modulation is employed. The PFM-dominated modulation is further defined by setting the frequency modulation range. Then, the ZVS range is extended to 95% of the switching cycle and the frequency modulation range is limited by frequency hopping, as shown in formula (2).

[0060] (2)

[0061] in, This is the rated switching frequency.

[0062] The intermediate load region specifically uses minimizing current stress as the modulation objective and employs PSM plus dynamic PDM three-degree-of-freedom control. Specifically, the PSM plus dynamic PDM three-degree-of-freedom control involves constructing a real-time optimization model and using an adaptive PSO algorithm to solve for the optimal solution set in real time. The specific steps are as follows.

[0063] Step A21: Construct the optimization objective function, as shown in formula (3).

[0064] (3)

[0065] in, This is the effective value of the inductor current. Compared to bridge-to-bridge movement, This represents the duty cycle of the original edge. For the secondary side duty cycle, For the switching cycle, This refers to the instantaneous inductor current;

[0066] Step A22: Construct the ZVS boundary conditions for the objective function, as shown in formula (4).

[0067] (4)

[0068] in, For the shutdown time, For the output capacitor of the switching transistor, Input voltage, This refers to the dead zone time.

[0069] The heavy-load region specifically aims to maximize transmission efficiency and reduce control complexity, employing PSM-dominated modulation. Specifically, PSM-dominated modulation involves using inter-bridge shifting. Single degree of freedom control reduces computational complexity.

[0070] Step B involves constructing a transient response switching control strategy for the three-phase dual active bridge converter based on the voltage transfer ratio and load change rate. The specific steps are as follows.

[0071] Step B1, calculate the voltage transfer ratio As shown in formula (5),

[0072] (5)

[0073] in, This is the effective value of the input voltage. This is the effective value of the output voltage;

[0074] Step B2, calculate the load change rate. As shown in formula (6),

[0075] (6);

[0076] Step B3, when At this time, due to voltage mismatch, forced intervention is implemented and a three-degree-of-freedom control mode of PSM plus dynamic PDM is adopted to suppress backflow power;

[0077] Step B4, when At this time, due to a sudden load change, forced intervention and the adoption of PFM control mode are used to accelerate the transient response.

[0078] Step C involves establishing an anti-three-phase imbalance mechanism for the three-phase dual active bridge converter. The specific steps are as follows:

[0079] Step C1: Implement closed-loop current balancing control and calculate the three-phase current imbalance in real time. As shown in formula (7),

[0080] (7)

[0081] in, , and For each phase inductor current, Average current;

[0082] Step C2: If the three-phase current imbalance δ > 10%, adjust the secondary duty cycle according to phase. As shown in formula (8),

[0083] (8)

[0084] in, To correct the duty cycle, The original duty cycle, This is the proportionality coefficient. Reference current;

[0085] Step C3 involves using space vector decoupling to eliminate interphase coupling effects, and then inserting a voltage equalization control sequence during the transient period to suppress DC bias current, thereby ensuring volt-second balance.

[0086] Step D involves using a steady-state response switching hysteresis control strategy, a transient response switching control strategy, and an anti-three-phase imbalance mechanism to complete the adaptive hybrid modulation operation of the three-phase dual active bridge converter.

[0087] like Figure 2 As shown, an adaptive hybrid modulation system for a three-phase dual active bridge converter based on partition optimization includes a steady-state response switching hysteresis control module, a transient response switching control module, an anti-three-phase imbalance module, and an adaptive hybrid modulation module. The steady-state response switching hysteresis control module dynamically divides the load range of the three-phase dual active bridge converter into light-load, medium-load, and heavy-load regions based on the load rate, and then constructs a steady-state response switching hysteresis control strategy for the light-load, medium-load, and heavy-load regions by combining the voltage transfer ratio and the load change rate. The transient response switching control module constructs a transient response switching control strategy for the three-phase dual active bridge converter based on the voltage transfer ratio and the load change rate. The anti-three-phase imbalance module establishes an anti-three-phase imbalance mechanism for the three-phase dual active bridge converter. The adaptive hybrid modulation module uses the steady-state response switching hysteresis control strategy, the transient response switching control strategy, and the anti-three-phase imbalance mechanism to complete the adaptive hybrid modulation operation of the three-phase dual active bridge converter.

[0088] To better illustrate the effects of the present invention, a specific embodiment of the method of the present invention is described below, such as... Figure 3 and Figure 4 As shown, for a light-load optimization scenario with a load rate β=20% and a voltage transfer ratio K=1.2, the PFM dominant modulation of this invention is adopted to the frequency modulation range. =38kHz, frequency jump extension ZVS implementation rate 98%, efficiency 93.5%;

[0089] like Figure 5 As shown, for a scenario with sudden load changes, the load rate β jumps from 40% to 90%, and the load change rate... =10% / ms, using the method of this invention for forced switching, the recovery time is 16ms, and the overshoot is less than 4%.

[0090] In summary, the adaptive hybrid modulation method and system for a three-phase dual active bridge converter based on partition optimization of the present invention first dynamically divides the load range of the three-phase dual active bridge converter into light load, medium load, and heavy load regions based on the load rate. Then, a steady-state response switching hysteresis control strategy is constructed for the light load, medium load, and heavy load regions based on the voltage transfer ratio and load change rate. Next, a transient response switching control strategy is constructed for the three-phase dual active bridge converter based on the voltage transfer ratio and load change rate. Subsequently, an anti-three-phase imbalance mechanism is established for the three-phase dual active bridge converter. Finally, the adaptive hybrid modulation operation of the three-phase dual active bridge converter is completed using the steady-state response switching hysteresis control strategy, the transient response switching control strategy, and the anti-three-phase imbalance mechanism. This effectively realizes the adaptive hybrid modulation of the three-phase dual active bridge converter. The hybrid modulation method and system have the function of dividing light load, medium load and heavy load regions based on load rate and adaptively selecting modulation strategies to optimize different objectives by combining voltage transfer ratio K and load change rate. Furthermore, PFM-dominated modulation, PSM plus dynamic PDM three-degree-of-freedom control and PSM-dominated modulation are respectively used for light load, medium load and heavy load regions to achieve full-condition efficiency optimization and transient performance improvement under wide voltage range and dynamic load. The set steady-state response switching hysteresis control strategy and transient response switching control strategy can suppress backflow power and accelerate transient response. At the same time, the set anti-three-phase imbalance mechanism can not only eliminate inter-phase coupling effect by using space vector decoupling, but also insert voltage equalization control sequence during transient period to suppress DC bias current and ensure volt-second balance.

[0091] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. An adaptive hybrid modulation method for a three-phase dual active bridge converter based on partition optimization, characterized in that: Includes the following steps, Step A: Based on the load rate, the load range of the three-phase dual active bridge converter is dynamically divided into light load, medium load and heavy load regions. Then, combined with the voltage transfer ratio and load change rate, a steady-state response switching hysteresis control strategy is constructed for the light load, medium load and heavy load regions. Step B: Construct a transient response switching control strategy for the three-phase dual active bridge converter based on the voltage transfer ratio and load change rate; Step C: Establish an anti-three-phase imbalance mechanism for the three-phase dual active bridge converter; Step D: The adaptive hybrid modulation operation of the three-phase dual active bridge converter is completed by using the steady-state response switching hysteresis control strategy, the transient response switching control strategy, and the anti-three-phase imbalance mechanism. The specific steps for step A are as follows: Step A1: Based on the load rate, the load range of the three-phase dual active bridge converter is dynamically divided into a light load zone, a medium load zone, and a heavy load zone according to the partition threshold. The load rate β threshold of the light load zone is less than 30%, the load rate β threshold of the medium load zone is not less than 30% and not greater than 80%, and the load rate β threshold of the heavy load zone is greater than 80%. Step A2: Combine voltage transfer ratio and load change rate to construct steady-state response switching hysteresis control strategy for light load region, medium load region and heavy load region. Specifically, in the light load region, minimizing circulating current loss is taken as the modulation target and PFM-dominated modulation is adopted. The intermediate load region specifically uses minimizing current stress as the modulation target and employs PSM plus dynamic PDM three-degree-of-freedom control. The heavy-load region specifically aims to maximize transmission efficiency and reduce control complexity, and adopts PSM-dominated modulation. In step A2, the use of PFM-dominated modulation specifically involves setting the frequency modulation range. Then, the ZVS range is extended to 95% of the switching cycle and the frequency modulation range is limited by frequency hopping, as shown in formula (2). （2） in, Rated switching frequency; In step A2, the PSM plus dynamic PDM three-degree-of-freedom control specifically involves constructing a real-time optimization model and using an adaptive PSO algorithm to solve for the optimal solution set in real time. The specific steps are as follows. Step A21: Construct the optimization objective function, as shown in formula (3). （3） in, This is the effective value of the inductor current. Compared to bridge-to-bridge movement, This represents the duty cycle of the original edge. For the secondary side duty cycle, For the switching cycle, This refers to the instantaneous inductor current. Step A22: Construct the ZVS boundary conditions for the objective function, as shown in formula (4). （4） in, For the shutdown time, For the output capacitor of the switching transistor, Input voltage, Dead time; In step A2, the PSM-dominated modulation specifically employs inter-bridge phase shifting. Single degree of freedom control reduces computational complexity.

2. The adaptive hybrid modulation method for a three-phase dual active bridge converter based on partition optimization according to claim 1, characterized in that: The partition threshold in step A1 is adaptively adjusted using an adaptive adjustment method based on leakage sensing temperature drift, as shown in formula (1). （1） in, For dynamic partitioning thresholds, As the baseline partition threshold, This represents the change in temperature drift due to leakage sensing. This is the baseline leakage inductance value.

3. The adaptive hybrid modulation method for a three-phase dual active bridge converter based on partition optimization according to claim 1, characterized in that: Step B involves constructing a transient response switching control strategy for the three-phase dual active bridge converter based on the voltage transfer ratio and load change rate. The specific steps are as follows. Step B1, calculate the voltage transfer ratio As shown in formula (5), （5） in, This is the effective value of the input voltage. This is the effective value of the output voltage; Step B2, calculate the load change rate. As shown in formula (6), （6）； Step B3, when At this time, due to voltage mismatch, forced intervention is implemented and a three-degree-of-freedom control mode of PSM plus dynamic PDM is adopted to suppress backflow power; Step B4, when the load change rate At this time, due to a sudden load change, forced intervention and the adoption of PFM control mode are used to accelerate the transient response.

4. The adaptive hybrid modulation method for a three-phase dual active bridge converter based on partition optimization according to claim 1, characterized in that: Step C involves establishing an anti-three-phase imbalance mechanism for the three-phase dual active bridge converter. The specific steps are as follows: Step C1: Implement closed-loop current balancing control and calculate the three-phase current imbalance in real time. As shown in formula (7), （7） in, , and For each phase inductor current, Average current; Step C2: If the three-phase current imbalance δ > 10%, adjust the secondary duty cycle according to phase. As shown in formula (8), （8） in, To correct the duty cycle, The original duty cycle, This is the proportionality coefficient. Reference current; Step C3 involves using space vector decoupling to eliminate interphase coupling effects, and then inserting a voltage equalization control sequence during the transient period to suppress DC bias current, thereby ensuring volt-second balance.

5. A three-phase dual active bridge converter adaptive hybrid modulation system based on partition optimization, wherein the specific adaptive hybrid modulation process of the three-phase dual active bridge converter adaptive hybrid modulation system is based on the adaptive hybrid modulation method according to any one of claims 1-4, characterized in that: It includes a steady-state response switching hysteresis control module, a transient response switching control module, an anti-three-phase imbalance module, and an adaptive hybrid modulation module. The steady-state response switching hysteresis control module is used to dynamically divide the load range of the three-phase dual active bridge converter into light load region, medium load region, and heavy load region based on the load rate, and then construct a steady-state response switching hysteresis control strategy for the light load region, medium load region, and heavy load region by combining the voltage transfer ratio and the load change rate. The transient response switching control module is used to construct a transient response switching control strategy for the three-phase dual active bridge converter based on the voltage transfer ratio and load change rate. The anti-three-phase imbalance module is used to establish an anti-three-phase imbalance mechanism for the three-phase dual active bridge converter; The adaptive hybrid modulation module is used to perform adaptive hybrid modulation of the three-phase dual active bridge converter by utilizing a steady-state response switching hysteresis control strategy, a transient response switching control strategy, and an anti-three-phase imbalance mechanism.

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