Control method for dual active bridge converter, apparatus, device and medium

Abstract

A control method for a dual active bridge converter, an apparatus, a device and a medium, relating to the field of converter control. The method comprises: analyzing a fundamental wave of a primary-side voltage and a fundamental wave of a secondary-side voltage on the basis of a phase angle relationship among an internal phase-shift angle, external phase-shift angle and φ phase angle of a primary side, so as to obtain a relationship between an output current and a switching frequency; regulating any one of the internal phase-shift angle and the external phase-shift angle of the primary side and the switching frequency; and, by means of the relationship between the output current and the switching frequency, calculating a current output current on the basis of a current internal phase-shift angle and external phase-shift angle of the primary side and a current switching frequency. Hence, the direct relationship between the output current and the switching frequency is obtained by analyzing the secondary-side voltage and the primary-side voltage, and then the output current is controlled by regulating the internal phase-shift angle or the external phase-shift angle of the primary side and the switching frequency, thereby realizing soft switching control over a full working range, allowing for a simple control mode, and reducing power consumption of the dual active bridge converter.

Description

A control method, apparatus, equipment and medium for a dual active bridge converter

[0001] This application claims priority to Chinese Patent Application No. 202510398225.5, filed on March 28, 2025, entitled "A Control Method, Apparatus, Device and Medium for a Dual Active Bridge Converter", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This invention relates to the field of converter control, and in particular to a control method, apparatus, device and medium for a dual active bridge converter. Background Technology

[0003] Commonly used control methods in DAB (Dual Active Bridge) converters include SPS (Signal-Phase-Shift), EPS (Extended-Phase-Shift), DPS (Dual-Phase-Shift), and TPS (Triple-Phase-Shift). Among them, TPS is the most flexible control method and is widely used in the control strategy of DAB converters. SPS, DPS, and EPS can all be considered as special cases of TPS. Specifically, please refer to Figure 1, which is a topology diagram of a dual active bridge converter disclosed in this invention. This dual active bridge converter includes a primary-side full-bridge circuit, a high-frequency transformer, and a secondary-side circuit. The primary-side full-bridge circuit includes a leading bridge arm and a lagging bridge arm, each including two MOSFETs. The high-frequency transformer includes a transformer and a secondary-side leakage inductance. The secondary-side circuit includes two sets of anti-phase connected switching transistors and two series-connected capacitors. The two sets of anti-phase connected switching transistors form a half-bridge circuit. The midpoints of the half-bridge circuit and the two series-connected capacitor circuits are connected to the secondary side of the high-frequency transformer. Based on this dual active bridge converter, EPS introduces two key control variables—the primary-side inner phase shift angle and the outer phase shift angle—on top of SPS, expanding the soft-switching range. However, under certain operating conditions, full-range soft-switching may still not be achievable. TPS requires simultaneous control of three phase shift angles: the primary-side inner phase shift angle, the outer phase shift angle, and the secondary-side inner phase shift angle. The control algorithm and implementation complexity are very high, making it difficult to achieve optimal performance in practical applications. Summary of the Invention

[0004] The purpose of this invention is to provide a control method, device, equipment, and medium for a dual active bridge converter. By analyzing the secondary and primary voltages, the direct relationship between the output current and the switching frequency can be obtained. Then, by adjusting the primary phase shift angle or the switching frequency, the output current can be controlled, achieving soft-switching control across the entire operating range. The control method is simple, reduces the power consumption of the dual active bridge converter, and minimizes energy loss.

[0005] In a first aspect, this application discloses a control method for a dual active bridge converter, including:

[0006] Obtain the waveforms of the secondary voltage and the primary voltage; the zero-crossing point of the transformer's secondary current is always the same as the commutation time of the lagging bridge arm.

[0007] The waveform diagram is analyzed to obtain the primary side inward phase shift angle, outward phase shift angle, and... The phase angle relationship; wherein, the inward phase shift angle and the outward phase shift angle of the primary side are both less than π;

[0008] Based on the phase angle relationship, the fundamental frequency of the primary voltage and the fundamental frequency of the secondary voltage are analyzed to obtain the relationship between the output current and the switching frequency.

[0009] Adjust any one of the primary side inward phase shift angle and the outer phase shift angle, as well as the switching frequency;

[0010] The current output current is calculated based on the relationship between the output current and the switching frequency, using the current primary phase shift angle, the outer phase shift angle, and the switching frequency.

[0011] Optionally, adjusting any one of the primary side inner phase shift angle, the outer phase shift angle, and the switching frequency includes:

[0012] Set the primary side inward phase shift angle to a constant value, and adjust the outward phase shift angle and the switching frequency;

[0013] Before calculating the current output current based on the current primary-side inward phase shift angle, the outer phase shift angle, and the switching frequency using the relationship between the output current and the switching frequency, the method further includes:

[0014] The current phase angle is calculated based on the current primary side inward phase shift angle and outward phase shift angle using the phase angle relationship. Phase angle;

[0015] The current output current is calculated based on the relationship between the output current and the switching frequency, using the current primary-side inward phase shift angle, the outer phase shift angle, and the switching frequency. This includes:

[0016] The relationship between the output current and the switching frequency is based on the current primary-side inner phase shift angle, the outer phase shift angle, and the... The phase angle and the switching frequency are used to calculate the current output current.

[0017] Optionally, adjusting any one of the primary side inner phase shift angle, the outer phase shift angle, and the switching frequency includes:

[0018] Set the outer phase shift angle to a constant value, and adjust the original side inner phase shift angle and the switching frequency;

[0019] Before calculating the current output current based on the current primary-side inward phase shift angle, the outer phase shift angle, and the switching frequency using the relationship between the output current and the switching frequency, the method further includes:

[0020] The current phase angle is calculated based on the current primary side inward phase shift angle and outward phase shift angle using the phase angle relationship. Phase angle;

[0021] The current output current is calculated based on the relationship between the output current and the switching frequency, using the current primary-side inward phase shift angle, the outer phase shift angle, and the switching frequency. This includes:

[0022] The relationship between the output current and the switching frequency is based on the current primary-side inner phase shift angle, the outer phase shift angle, and the... The phase angle and the switching frequency are used to calculate the current output current.

[0023] Optionally, before obtaining the waveforms of the secondary and primary voltages, the following steps are also included:

[0024] The two MOSFETs of the leading bridge arm are turned on at 50% complementary ratio, and the two MOSFETs of the lagging bridge arm are turned on at 50% complementary ratio;

[0025] In the control secondary circuit, the switch transistors with the opposite phase to the output voltage in the two sets of anti-phase connected switches are turned on, and the switches with the same phase as the output voltage in the two sets of anti-phase connected switches are complementary and 50% turned on.

[0026] Optionally, the phase angle relationship is that the outward phase shift angle is equal to half the difference between the original side inward phase shift angle and π, and the... The sum of phase angles.

[0027] Optionally, the fundamental frequencies of the primary-side voltage and the secondary-side voltage are analyzed based on the phase angle relationship to obtain the relationship between the output current and the switching frequency, including:

[0028] The resonant cavity within the dual active bridge converter is equivalently transformed to obtain an equivalent LC series resonant circuit.

[0029] Calculate the equivalent impedance of the equivalent LC series resonant circuit;

[0030] Fourier analysis is performed on the primary voltage and the secondary voltage to obtain the fundamental frequency of the primary voltage and the fundamental frequency of the secondary voltage;

[0031] Based on the phase angle relationship and the equivalent impedance, the fundamental frequency of the primary voltage, the fundamental frequency of the secondary voltage, and the fundamental frequency of the current are analyzed to obtain the relationship between the output current and the switching frequency.

[0032] Secondly, this application discloses a control system for a dual active bridge converter, comprising:

[0033] The acquisition module is used to acquire waveforms of the secondary voltage and the primary voltage; wherein, the zero-crossing point of the secondary current of the transformer is always kept at the same time as the commutation of the lagging arm;

[0034] The first analysis module is used to analyze the waveform to obtain the inward phase shift angle, the outward phase shift angle, and the... The phase angle relationship; wherein, the inward phase shift angle and the outward phase shift angle of the primary side are both less than π;

[0035] The second analysis module is used to analyze the fundamental frequency of the primary voltage and the fundamental frequency of the secondary voltage based on the phase angle relationship, so as to obtain the relationship between the output current and the switching frequency.

[0036] The adjustment module is used to adjust any one of the primary side inner phase shift angle and the outer phase shift angle, as well as the switching frequency;

[0037] The calculation module is used to calculate the current output current based on the relationship between the output current and the switching frequency, using the current primary side inward phase shift angle, the outer phase shift angle, and the switching frequency.

[0038] Thirdly, this application discloses an electronic device, including:

[0039] Memory, used to store computer programs;

[0040] A processor is used to execute the computer program to implement the control method for the dual active bridge converter as described above.

[0041] Fourthly, this application discloses a computer-readable storage medium for storing a computer program, wherein the computer program, when executed by a processor, implements the control method of the dual active bridge converter as described above.

[0042] This application provides a control method, apparatus, device, and medium for a dual active bridge converter. The method includes: acquiring waveforms of the secondary and primary voltages; wherein the zero-crossing point of the secondary current of the transformer is always kept at the same time as the commutation moment of the lagging bridge arm; and analyzing the waveforms to obtain the primary side inner phase shift angle, outer phase shift angle, and... The phase angle relationship is established; where both the primary side inward and outward phase shift angles are less than π. Based on this phase angle relationship, the fundamental frequencies of the primary and secondary voltages are analyzed to obtain the relationship between the output current and the switching frequency. Any one of the primary side inward and outward phase shift angles and the switching frequency is adjusted. The current output current is calculated based on the current primary side inward and outward phase shift angles and the switching frequency, using the relationship between the output current and the switching frequency. Therefore, this application obtains a direct relationship between the output current and the switching frequency by analyzing the secondary and primary voltages, and then controls the output current by adjusting the primary side inward or outward phase shift angle and the switching frequency. This achieves soft-switching control across the entire operating range, simplifies the control method, reduces the power consumption of the dual active bridge converter, and minimizes energy loss. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the prior art and embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 is a topology diagram of a dual active bridge converter disclosed in this invention;

[0045] Figure 2 is a flowchart of a control method for a dual active bridge converter provided by the present invention;

[0046] Figure 3 is a waveform diagram of the primary voltage, secondary voltage, and internal current of a transformer disclosed in this invention;

[0047] Figure 4 is a topology diagram of another dual active bridge converter disclosed in this invention;

[0048] Figure 5 is an equivalent LC series resonant circuit diagram disclosed in this invention;

[0049] Figure 6 is a fundamental vector diagram of the input voltage, output voltage, and current of an equivalent LC series resonant circuit disclosed in this invention.

[0050] Figure 7 is a topology diagram of the dual active bridge converter of the first multi-input system disclosed in this invention;

[0051] Figure 8 is a topology diagram of the dual active bridge converter of the second multi-input system disclosed in this invention;

[0052] Figure 9 is a schematic diagram of the control system of a dual active bridge converter disclosed in this invention;

[0053] Figure 10 is a structural diagram of an electronic device disclosed in this invention. Detailed Implementation

[0054] The core of this invention is to provide a control method, device, equipment, and medium for a dual active bridge converter. By analyzing the secondary and primary voltages, the direct relationship between the output current and the switching frequency can be obtained. Then, by adjusting the primary phase shift angle or the switching frequency, the output current can be controlled, achieving soft-switching control across the entire operating range. The control method is simple, reduces the power consumption of the dual active bridge converter, and minimizes energy loss.

[0055] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, 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] Specifically, please refer to Figure 2, which is a flowchart of a control method for a dual active bridge converter provided by the present invention. It should be noted that the present invention uses the topology diagram of the dual active bridge converter in Figure 1 as an example.

[0057] This application provides a control method for a dual active bridge converter, including:

[0058] S11. Obtain the waveforms of the secondary voltage and the primary voltage.

[0059] This dual active bridge converter includes a primary-side full-bridge circuit, a high-frequency transformer, and a secondary-side circuit. The primary-side full-bridge circuit includes a leading arm and a lagging arm. The lagging arm includes a first MOSFET Q1 and a second MOSFET Q2, and the leading arm includes a third MOSFET Q3 and a fourth MOSFET Q4. The high-frequency transformer includes a transformer and a secondary-side leakage inductance L. rThe secondary circuit includes two sets of anti-phase connected switching transistors and two series-connected capacitors. The two sets of anti-phase connected switching transistors form a half-bridge circuit. The midpoints of both the half-bridge circuit and the series capacitor circuit on the secondary side are connected to the secondary side of the high-frequency transformer. The two sets of anti-phase connected switching transistors are divided into an upper bridge arm and a lower bridge arm. The upper bridge arm includes the fifth MOSFET Q5 and the sixth MOSFET Q6, and the lower bridge arm includes the seventh MOSFET Q7 and the eighth MOSFET Q8. The two series-connected capacitors are the first capacitor C1 and the second capacitor C2. The body diodes of Q1, Q2, Q3, Q4, Q5, Q6, Q7, and Q8 have opposite conduction directions to their own. The conduction directions of Q6 and Q8 are opposite to the phase of the output voltage, while the conduction directions of Q5 and Q6 are the same phase as the output voltage. The secondary leakage inductance can be an integrated inductor inside the transformer or an external independent inductor.

[0060] In this embodiment, before obtaining the waveforms of the secondary and primary voltages, the method further includes: controlling the two MOSFETs of the leading bridge arm to conduct complementaryly by 50%, and the two MOSFETs of the lagging bridge arm to conduct complementaryly by 50%; controlling the switching transistors in the two sets of anti-phase connected switches in the secondary circuit to conduct with the switching transistors opposite in phase to the output voltage, and the switching transistors in the two sets of anti-phase connected switches to conduct complementaryly by 50%. Specifically, Q3 and Q4 are controlled to conduct complementaryly by 50%, and Q1 and Q2 are also controlled to conduct complementaryly by 50%; during the positive half-cycle of the AC power grid, Q6 and Q8 are controlled to conduct continuously, and Q5 and Q7 are controlled to conduct complementaryly by 50%; during the negative half-cycle of the AC power grid, Q5 and Q7 are controlled to conduct continuously, and Q6 and Q8 are controlled to conduct complementaryly by 50%.

[0061] Obtain the waveforms of the primary and secondary voltages. Specifically, please refer to Figure 3, which shows the waveforms of the primary and secondary voltages and the transformer internal current disclosed in this invention. Here, ir represents the transformer internal current. The zero-crossing point of the transformer's secondary current always remains the same as the commutation time of the lagging arm, ensuring the ZCS (Zero Current Switching) of the lagging arm.

[0062] S12. Analyze the waveform to obtain the primary side inward phase shift angle, outward phase shift angle, and... The phase angle relationship; where both the inward and outward phase angles of the primary side are less than π.

[0063] As shown in the waveform diagram, when Q3 is on, Q2 turns on after a delay in the inward phase angle following the on of Q3, at which point the primary voltage is in the positive half-cycle. Q7 turns on after a delay in the outward phase angle following the on of Q2, at which point the secondary voltage is in the positive half-cycle. If Q1 is switched on and Q3 is switched off, the primary voltage is 0 and the secondary voltage is in the positive half-cycle. Q4 turns on after a delay in the inward phase angle following the on of Q1, at which point the primary voltage is in the negative half-cycle. Q5 turns on after a delay in the outward phase angle following the on of Q4, at which point the secondary voltage is in the negative half-cycle. If Q3 is switched on and Q1 is switched off, the primary voltage is 0 and the secondary voltage is in the negative half-cycle. Q2 turns on after a delay in the inward phase angle following the on of Q3, at which point the primary voltage is in the positive half-cycle and the secondary voltage is in the negative half-cycle. The waveforms of the primary and secondary voltages change regularly within the period.

[0064] In this embodiment, the phase angle relationship can be that the outer phase shift angle is equal to half the difference between the original side inner phase shift angle and π. The sum of phase angles is given by the following formula:

[0065] Where θ is the inner phase shift angle and α is the outer phase shift angle. This represents the phase angle by which the secondary voltage lags behind the primary voltage.

[0066] In addition, the voltage gain ratio of the dual active bridge converter topology is calculated based on the ratio of the number of turns in the secondary winding to the number of turns in the primary winding of the transformer, the input voltage, and the output voltage. The specific formula is as follows:

[0067] Where, r V The voltage gain ratio is the current voltage ratio, where n is the ratio of the number of turns in the secondary winding to the number of turns in the primary winding of the transformer, and V. pv V is the input voltage. g This is the output voltage.

[0068] S13. Analyze the fundamental frequency of the primary voltage and the fundamental frequency of the secondary voltage based on the phase angle relationship to obtain the relationship between the output current and the switching frequency.

[0069] The fundamental frequency is the main frequency component in the voltage waveform and usually determines the basic characteristics of the circuit. In this dual active bridge converter, the switching action of the MOSFET and the switching transistor will generate rich harmonic components, but the energy transfer is mainly determined by the fundamental frequency. By extracting the fundamental frequencies of the primary voltage and the secondary voltage, the analysis process can be simplified while retaining the main characteristics of the circuit.

[0070] S14. Adjust any one of the primary side inner phase shift angle and outer phase shift angle, and the switching frequency;

[0071] S15. Calculate the current output current based on the relationship between the output current and the switching frequency, using the current primary side inner phase shift angle, outer phase shift angle, and switching frequency.

[0072] In this embodiment, the primary side inner phase shift angle is used to achieve ZVS and reduce switching losses; the outer phase shift angle directly determines the direction and magnitude of energy transmission. The larger the outer phase shift angle, the greater the transmission power and the greater the output current; the output current is a direct reflection of the output power, and the switching frequency is negatively correlated with the output current.

[0073] In the first specific embodiment, adjusting either the primary side inner phase shift angle or the outer phase shift angle, and the switching frequency, includes: setting the primary side inner phase shift angle to a constant value, and adjusting the outer phase shift angle and the switching frequency; before calculating the current output current based on the current primary side inner phase shift angle, outer phase shift angle, and switching frequency using the relationship between the output current and the switching frequency, it further includes: calculating the current output current based on the current primary side inner phase shift angle and outer phase shift angle using the phase angle relationship. Phase angle; the current output current is calculated based on the relationship between the output current and the switching frequency, using the current primary side inner phase shift angle, outer phase shift angle, and switching frequency. This includes: calculating the current output current based on the relationship between the output current and the switching frequency, using the current primary side inner phase shift angle, outer phase shift angle, and switching frequency. The phase angle and switching frequency are used to calculate the current output current. Specifically, increasing the outer phase angle increases the transmission power and output current; conversely, decreasing the outer phase angle decreases the transmission power and output current. It's important to note that an excessively large outer phase angle may increase current stress or cause soft-switching failure, so adjustments must be made based on the specific circumstances. Furthermore, the output current directly reflects the output power. Higher switching frequencies result in higher energy consumption and lower output current for the dual active bridge converter, while lower switching frequencies result in lower energy consumption and higher output current.

[0074] In the second specific embodiment, adjusting either the primary side inner phase shift angle or the outer phase shift angle, and the switching frequency, includes: setting the outer phase shift angle to a constant value, and adjusting the primary side inner phase shift angle and the switching frequency; before calculating the current output current based on the current primary side inner phase shift angle, outer phase shift angle, and switching frequency using the relationship between the output current and the switching frequency, it further includes: calculating the current output current based on the current primary side inner phase shift angle and outer phase shift angle using the phase angle relationship. Phase angle; the current output current is calculated based on the relationship between the output current and the switching frequency, using the current primary side inner phase shift angle, outer phase shift angle, and switching frequency. This includes: calculating the current output current based on the relationship between the output current and the switching frequency, using the current primary side inner phase shift angle, outer phase shift angle, and switching frequency. The phase angle and switching frequency are used to calculate the current output current. Specifically, by adjusting the on-time and off-time of the MOSFET in the lagging bridge arm, the resonant cavity of the dual active bridge converter is used to make the MOSFET turn on and off at zero voltage, so that the output current naturally drops to zero before the MOSFET is turned off, reducing switching losses.

[0075] As can be seen, this application obtains the direct relationship between output current and switching frequency by analyzing the secondary voltage and primary voltage. Then, by adjusting the primary phase shift angle (inner or outer) and the switching frequency, the output current is controlled, realizing soft-switching control across the entire operating range. The control method is simple, reduces the power consumption of the dual active bridge converter, and reduces energy loss.

[0076] Based on the above embodiments:

[0077] As an optional embodiment, the fundamental frequencies of the primary and secondary voltages are analyzed based on the phase angle relationship to obtain the relationship between the output current and the switching frequency, including:

[0078] The resonant cavity in the dual active bridge converter is equivalently transformed to obtain an equivalent LC series resonant circuit.

[0079] Calculate the equivalent impedance of the equivalent LC series resonant circuit;

[0080] Fourier analysis is performed on the primary and secondary voltages to obtain the fundamental frequencies of the primary and secondary voltages.

[0081] Based on the phase angle relationship and equivalent impedance, the fundamental frequencies of the primary voltage, secondary voltage, and current are analyzed to obtain the relationship between the output current and the switching frequency.

[0082] In this embodiment, the resonant cavity within the dual active bridge converter is equivalently represented to obtain an equivalent LC series resonant circuit, wherein the resonant cavity includes a secondary leakage inductance L. r and resonant capacitor C r Resonant capacitor C r Let C1 be the first capacitor and C2 be the second capacitor; if the high-frequency transformer also includes a third capacitor C3, then the resonant capacitor C... r The third capacitor is C3. Specifically, please refer to Figure 4, which is a topology diagram of another dual active bridge converter disclosed in this invention. If the resonant capacitor C... r If the first capacitor is C1 and the second capacitor is C2, then the equivalent LC series resonant circuit is shown in Figure 5, which is an equivalent LC series resonant circuit diagram disclosed in this invention. For this equivalent LC series resonant circuit, the fundamental vector diagrams of the input voltage, output voltage, and current are shown in Figure 6. Here, ir is the internal current of the transformer, and β is the phase angle between the internal current of the transformer and the primary voltage.

[0083] The equivalent impedance of the equivalent LC series resonant circuit is calculated using the following formula:

[0084] Among them, Z r For the equivalent impedance, f s L is the switching frequency.r For secondary side leakage, C r It is a resonant capacitor.

[0085] It should be noted that f s The current phase is greater than f0, where f0 is the resonant frequency of the resonant cavity itself. Therefore, this resonant topology operates in the inductive region, and the current phase lags behind the voltage phase by π / 2.

[0086] Performing Fourier analysis on the primary voltage yields the fundamental frequency of the primary voltage, as shown in the following formula:

[0087] Among them, V s1 Let f be the fundamental frequency of the primary voltage, θ be the internal phase shift angle, n be the ratio of the number of turns in the secondary winding to the number of turns in the primary winding of the transformer, and f be the fundamental frequency of the primary voltage. s V is the switching frequency. pv t represents the input voltage and t represents the switching time.

[0088] Performing Fourier analysis on the secondary voltage yields the fundamental frequency of the secondary voltage, as shown in the following formula:

[0089] Among them, V p1 This is the fundamental frequency of the primary voltage. f is the phase angle by which the secondary voltage lags the primary voltage. s V is the switching frequency. g t represents the output voltage and t represents the switching time.

[0090] Then, through complex plane analysis, and by using the formulas for the fundamental frequency of the input primary voltage, the fundamental frequency of the negative voltage, and the fundamental frequency of the current, the output current can be obtained. Meanwhile, under ideal conditions, the input power always equals the output power. The specific formula is as follows:

[0091] Where P is the input power, V pv Where θ is the input voltage, θ is the internal phase shift angle, and n is the ratio of the number of turns in the secondary winding to the number of turns in the primary winding of the transformer. Z is the phase angle by which the secondary voltage lags behind the primary voltage. r Where I is the equivalent impedance, I is the output current, and V is the output current. g For the output voltage, r V This represents the current voltage gain ratio.

[0092] By combining equations (3) and (6), we obtain the expression for the relationship between the switching frequency and the output current I, as follows:

[0093] Where θ is the inner phase shift angle, L is the phase angle by which the secondary voltage lags behind the primary voltage. rI is the secondary leakage inductance, and V is the output current. g For the output voltage, C r For resonant capacitance, r V This represents the current voltage gain ratio.

[0094] Furthermore, if the dual active bridge converter is a multi-input system, the topology of the dual active bridge converter of the multi-input system can be seen in Figures 7 and 8. Figure 7 is a topology diagram of the first type of dual active bridge converter of the multi-input system disclosed in this invention, and Figure 8 is a topology diagram of the second type of dual active bridge converter of the multi-input system disclosed in this invention.

[0095] As can be seen, this embodiment uses the phase angle relationship and the equivalent impedance of the resonant cavity in the dual active bridge converter to analyze the fundamental waves of the primary voltage, the secondary voltage, and the current, so as to obtain the relationship between the output current and the switching frequency. The output current can be controlled by adjusting the inward or outward phase shift angle of the primary side and the switching frequency, which can quickly control the amplitude and direction of the output current, reduce the power consumption of the dual active bridge converter, and reduce energy loss.

[0096] This application also provides a control system for a dual active bridge converter. Specifically, please refer to Figure 9, which is a schematic diagram of the structure of a control system for a dual active bridge converter disclosed in this invention, including:

[0097] The acquisition module 11 is used to acquire waveforms of the secondary voltage and the primary voltage; wherein, the zero-crossing point of the secondary current of the transformer is always the same as the commutation time of the lagging bridge arm;

[0098] The first analysis module 12 is used to analyze the waveform to obtain the inward phase shift angle, the outward phase shift angle, and the... The phase angle relationship; where both the inward and outward phase shift angles of the primary side are less than π;

[0099] The second analysis module 13 is used to analyze the fundamental frequency of the primary side voltage and the fundamental frequency of the secondary side voltage based on the phase angle relationship, so as to obtain the relationship between the output current and the switching frequency.

[0100] Adjustment module 14 is used to adjust any one of the primary side inner phase shift angle and outer phase shift angle, as well as the switching frequency;

[0101] The calculation module 15 is used to calculate the current output current based on the current primary side inner phase shift angle, outer phase shift angle, and switching frequency by means of the relationship between the output current and the switching frequency.

[0102] As can be seen, this application obtains the direct relationship between output current and switching frequency by analyzing the secondary voltage and primary voltage. Then, by adjusting the primary phase shift angle or the switching frequency, the output current is controlled, realizing soft-switching control across the entire operating range. The control method is simple, reduces the power consumption of the dual active bridge converter, and reduces energy loss.

[0103] In some specific embodiments, the adjustment module 14 includes:

[0104] The first adjustment unit is used to set the primary side inner phase shift angle to a constant value and adjust the outer phase shift angle and switching frequency.

[0105] The control system for the dual active bridge converter also includes:

[0106] The first phase angle calculation unit is used to calculate the current phase angle based on the current primary side inner and outer phase angles through the phase angle relationship. Phase angle;

[0107] Calculation module 15 includes:

[0108] The first output current calculation unit is used to calculate the output current based on the relationship between the output current and the switching frequency, and the current primary side inner phase shift angle, outer phase shift angle, and... The phase angle and switching frequency are used to calculate the current output current.

[0109] In some specific embodiments, the adjustment module 14 includes:

[0110] The second adjustment unit is used to set the outer phase shift angle to a constant value and adjust the primary side inner phase shift angle and the switching frequency.

[0111] The control system for the dual active bridge converter also includes:

[0112] The second phase angle calculation unit is used to calculate the current phase angle based on the current primary side inner and outer phase angles through the phase angle relationship. Phase angle;

[0113] Calculation module 15 includes:

[0114] The second output current calculation unit is used to calculate the output current based on the relationship between the output current and the switching frequency, and the current primary side inner phase shift angle, outer phase shift angle, and... The phase angle and switching frequency are used to calculate the current output current.

[0115] In some specific implementations, the control system of the dual active bridge converter further includes:

[0116] The first control unit is used to control the two MOSFETs of the leading bridge arm to conduct in a complementary 50% manner and the two MOSFETs of the lagging bridge arm to conduct in a complementary 50% manner.

[0117] The second control unit is used to control the conduction of the two sets of anti-phase connected switching transistors in the secondary circuit, where the switching transistors with the same phase as the output voltage are opposite to the output voltage, and the complementary 50% conduction of the two sets of anti-phase connected switching transistors with the same phase as the output voltage.

[0118] In some specific implementations, the phase angle relationship is that the outer phase shift angle is equal to half the difference between the original side's inner phase shift angle and π. The sum of phase angles.

[0119] In some specific embodiments, the second analysis module 13 includes:

[0120] Equivalent units are used to equivalence the resonant cavity in the dual active bridge converter to obtain an equivalent LC series resonant circuit.

[0121] Equivalent impedance calculation unit, used to calculate the equivalent impedance of an equivalent LC series resonant circuit;

[0122] The Fourier analysis unit is used to perform Fourier analysis on the primary and secondary voltages to obtain the fundamental frequency of the primary voltage and the fundamental frequency of the secondary voltage.

[0123] The analysis unit is used to analyze the fundamental frequency of the primary voltage, the fundamental frequency of the secondary voltage, and the fundamental frequency of the current based on the phase angle relationship and the equivalent impedance, so as to obtain the relationship between the output current and the switching frequency.

[0124] Furthermore, this application also discloses an electronic device. Figure 10 is a structural diagram of an electronic device disclosed in this invention. The content in the figure should not be considered as any limitation on the scope of use of this application. The electronic device 20 may specifically include: at least one processor 21, at least one memory 22, a power supply 23, a communication interface 24, an input / output interface 25, and a communication bus 26. The memory 22 is used to store a computer program, which is loaded and executed by the processor 21 to implement the relevant steps in the control method of the dual active bridge converter disclosed in any of the foregoing embodiments. Additionally, the electronic device 20 in this embodiment may specifically be an electronic computer.

[0125] In this embodiment, the power supply 23 is used to provide operating voltage for each hardware device on the electronic device 20; the communication interface 24 can create a data transmission channel between the electronic device 20 and external devices, and the communication protocol it follows can be any communication protocol applicable to the technical solution of this application, and is not specifically limited here; the input / output interface 25 is used to acquire external input data or output data to the outside world, and its specific interface type can be selected according to specific application needs, and is not specifically limited here.

[0126] In addition, the memory 22, as a carrier for resource storage, can be a read-only memory, random access memory, disk or optical disk, etc. The resources stored thereon can include operating system 221, computer program 222, etc., and the storage method can be temporary storage or permanent storage.

[0127] The operating system 221 is used to manage and control the various hardware devices on the electronic device 20 and the computer program 222, which may be Windows Server, Netware, Unix, Linux, etc. In addition to including a computer program capable of performing the control method of the dual active bridge converter executed by the electronic device 20 as disclosed in any of the foregoing embodiments, the computer program 222 may further include a computer program capable of performing other specific tasks.

[0128] Furthermore, this application also discloses a computer-readable storage medium for storing a computer program; wherein, when the computer program is executed by a processor, it implements the DC voltage control of the aforementioned disclosed inverter. Specific steps of this method can be found in the corresponding content disclosed in the foregoing embodiments, and will not be repeated here.

[0129] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0130] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0131] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A control method for a dual active bridge converter, characterized in that, include: Obtain the waveforms of the secondary voltage and the primary voltage; the zero-crossing point of the transformer's secondary current is always the same as the commutation time of the lagging bridge arm. The waveform diagram is analyzed to obtain the primary side inward phase shift angle, outward phase shift angle, and... The phase angle relationship; wherein, the inward phase shift angle and the outward phase shift angle of the primary side are both less than π; Based on the phase angle relationship, the fundamental frequency of the primary voltage and the fundamental frequency of the secondary voltage are analyzed to obtain the relationship between the output current and the switching frequency. Adjust any one of the primary side inward phase shift angle and the outer phase shift angle, as well as the switching frequency; The current output current is calculated based on the relationship between the output current and the switching frequency, using the current primary phase shift angle, the outer phase shift angle, and the switching frequency.

2. The control method for a dual active bridge converter as described in claim 1, characterized in that, Adjusting any one of the primary side inward phase shift angle and the outer phase shift angle, and the switching frequency, includes: Set the primary side inward phase shift angle to a constant value, and adjust the outward phase shift angle and the switching frequency; Before calculating the current output current based on the current primary-side inward phase shift angle, the outer phase shift angle, and the switching frequency using the relationship between the output current and the switching frequency, the method further includes: The current phase angle is calculated based on the current primary side inward phase shift angle and outward phase shift angle using the phase angle relationship. Phase angle; The current output current is calculated based on the relationship between the output current and the switching frequency, using the current primary-side inward phase shift angle, the outer phase shift angle, and the switching frequency. This includes: The relationship between the output current and the switching frequency is based on the current primary-side inner phase shift angle, the outer phase shift angle, and the... The phase angle and the switching frequency are used to calculate the current output current.

3. The control method for a dual active bridge converter as described in claim 1, characterized in that, Adjusting any one of the primary side inward phase shift angle and the outer phase shift angle, and the switching frequency, includes: Set the outer phase shift angle to a constant value, and adjust the original side inner phase shift angle and the switching frequency; Before calculating the current output current based on the current primary-side inward phase shift angle, the outer phase shift angle, and the switching frequency using the relationship between the output current and the switching frequency, the method further includes: The current phase angle is calculated based on the current primary side inward phase shift angle and outward phase shift angle using the phase angle relationship. Phase angle; The current output current is calculated based on the relationship between the output current and the switching frequency, using the current primary-side inward phase shift angle, the outer phase shift angle, and the switching frequency. This includes: The relationship between the output current and the switching frequency is based on the current primary-side inner phase shift angle, the outer phase shift angle, and the... The phase angle and the switching frequency are used to calculate the current output current.

4. The control method for a dual active bridge converter as described in claim 1, characterized in that, Before obtaining the waveforms of the secondary and primary voltages, the following steps are also included: The two MOSFETs of the leading bridge arm are turned on at 50% complementary ratio, and the two MOSFETs of the lagging bridge arm are turned on at 50% complementary ratio; In the control secondary circuit, the switch transistors with the opposite phase to the output voltage in the two sets of anti-phase connected switches are turned on, and the switches with the same phase as the output voltage in the two sets of anti-phase connected switches are complementary and 50% turned on.

5. The control method for a dual active bridge converter as described in claim 1, characterized in that, The phase angle relationship is that the outer phase shift angle is equal to half the difference between the original side inner phase shift angle and π, and the... The sum of phase angles.

6. The control method for a dual active bridge converter as described in any one of claims 1 to 5, characterized in that, Based on the phase angle relationship, the fundamental frequencies of the primary and secondary voltages are analyzed to obtain the relationship between the output current and the switching frequency, including: The resonant cavity within the dual active bridge converter is equivalently transformed to obtain an equivalent LC series resonant circuit. Calculate the equivalent impedance of the equivalent LC series resonant circuit; Fourier analysis is performed on the primary voltage and the secondary voltage to obtain the fundamental frequency of the primary voltage and the fundamental frequency of the secondary voltage; Based on the phase angle relationship and the equivalent impedance, the fundamental frequency of the primary voltage, the fundamental frequency of the secondary voltage, and the fundamental frequency of the current are analyzed to obtain the relationship between the output current and the switching frequency.

7. A control system for a dual active bridge converter, characterized in that, include: The acquisition module is used to acquire waveforms of the secondary voltage and the primary voltage; wherein, the zero-crossing point of the secondary current of the transformer is always kept at the same time as the commutation of the lagging arm; The first analysis module is used to analyze the waveform to obtain the inward phase shift angle, the outward phase shift angle, and the... The phase angle relationship; wherein, the inward phase shift angle and the outward phase shift angle of the primary side are both less than π; The second analysis module is used to analyze the fundamental frequency of the primary voltage and the fundamental frequency of the secondary voltage based on the phase angle relationship, so as to obtain the relationship between the output current and the switching frequency. The adjustment module is used to adjust any one of the primary side inner phase shift angle and the outer phase shift angle, as well as the switching frequency; The calculation module is used to calculate the current output current based on the relationship between the output current and the switching frequency, using the current primary side inward phase shift angle, the outer phase shift angle, and the switching frequency.

8. An electronic device, characterized in that, include: Memory, used to store computer programs; A processor for executing the computer program to implement the control method for the dual active bridge converter as described in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, Used to store a computer program, wherein the computer program, when executed by a processor, implements the control method of the dual active bridge converter as described in any one of claims 1 to 6.

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