A method, apparatus and assembly for output voltage compensation of a dual active bridge converter

Abstract

This invention discloses an output voltage compensation method, apparatus, and components for a dual active bridge converter. The method includes obtaining a first voltage and a first current from the grid-side power supply, and a second voltage and capacitance value from the integrator module; determining the start point for interpolation compensation of the output voltage of the energy storage output module based on the zero-crossing time of the first voltage; the start point for interpolation compensation is a target time after the zero-crossing time; determining the voltage compensation amount at the end point of interpolation compensation based on the first voltage and first current from the grid-side power supply, the second voltage and capacitance value of the integrator module, and the switching cycle of the switching module of the secondary bridge arm circuit; determining the interpolation time based on the voltage compensation amount of the integrator module at the end point of interpolation compensation; and controlling the conduction state of the secondary bridge arm circuit at the start point of interpolation compensation using the interpolation time to adjust the average value of the output voltage of the energy storage output module to be continuous before and after the zero-crossing time of the first voltage. The technical solution provided by this invention improves the oscillation of the output voltage.

Description

Technical Field

[0001] This invention relates to the field of converter technology, and in particular to a method, apparatus and components for output voltage compensation of a dual active bridge converter. Background Technology

[0002] The dual active bridge converter is a typical single-stage converter with advantages such as symmetrical structure, bidirectional power transmission, electrical isolation, and high power density. It is widely used in various DC-DC or DC-AC scenarios. The traditional control method for the dual active bridge converter is to adjust the phase shift angle (inner or outer phase shift angle) between each bridge arm under the premise of fixed switching frequency, such as single phase shift, extended phase shift, and dual phase shift control.

[0003] However, near the moments before and after the grid-side power supply voltage crosses zero, the average voltage of the energy storage output module is discontinuous and deviates from the grid-side power supply voltage, causing the output voltage of the energy storage output module to oscillate poorly. Summary of the Invention

[0004] This invention provides a method, apparatus, and component for compensating the output voltage of a dual active bridge converter, which solves the problem that the average voltage of the energy storage output module is discontinuous and deviates from the voltage of the grid-side power supply at the moments corresponding to the zero-crossing of the grid-side power supply, resulting in poor oscillation of the output voltage of the energy storage output module.

[0005] According to one aspect of the present invention, an output voltage compensation method for a dual active bridge converter is provided, the dual active bridge converter comprising: a primary side bridge arm circuit, a transformer module, a secondary side bridge arm circuit, an energy storage output module, a grid-side power supply, and an integrating module connected to the secondary coil of the transformer module;

[0006] The method includes:

[0007] Obtain the first voltage and first current of the grid-side power supply, and the second voltage and capacitance value of the integration module;

[0008] Based on the zero-crossing time of the first voltage, determine the start point for the interpolation compensation of the output voltage of the energy storage output module;

[0009] Based on the first voltage and first current of the grid-side power supply, the second voltage and capacitance value of the integration module, and the switching cycle of the switching module of the secondary bridge arm circuit, the voltage compensation amount of the integration module at the end point of the insertion compensation is determined.

[0010] The insertion time is determined based on the voltage compensation amount of the integral module at the end point of the insertion compensation.

[0011] At the starting point of the insertion compensation, the conduction state of the secondary bridge arm circuit is controlled by the insertion time, so as to adjust the average value of the output voltage of the energy storage output module to be continuous before and after the zero-crossing point of the first voltage.

[0012] Optionally, the secondary bridge arm circuit is connected between the secondary coil of the transformer module and the energy storage output module, and the grid-side power supply is connected in parallel with the energy storage output module;

[0013] The step of determining the voltage compensation amount of the integration module at the end point of the insertion compensation based on the first voltage and first current of the grid-side power supply, the second voltage capacitor value of the integration module, and the switching cycle of the switching module of the secondary bridge arm circuit includes:

[0014] Based on the first voltage and first current of the grid-side power supply, the second voltage and capacitance value of the integration module, and the switching cycle of the switching module of the secondary bridge arm circuit, the total charge amount to be compensated for the output voltage of the energy storage output module during the compensation period is determined.

[0015] Based on the total charge to be compensated in the output voltage and the capacitance value of the integration module, the voltage compensation amount of the integration module at the end point of the interpolation compensation is determined.

[0016] Optionally, determining the total charge amount to be compensated for the output voltage of the energy storage output module during the compensation period based on the first voltage and first current of the grid-side power supply, the second voltage and capacitance value of the integration module, and the switching cycle of the switching module of the secondary bridge arm circuit includes:

[0017] Based on the second voltage of the integrator module, the capacitance value of the integrator module, and the switching cycle of the switching module of the secondary bridge arm circuit, the corresponding first charge amount of the integrator module during the compensation period is determined.

[0018] Based on the first current of the grid-side power supply, determine the second charge quantity corresponding to the first current of the grid-side power supply during the compensation period;

[0019] Based on the first voltage of the grid-side power supply, determine the third charge quantity corresponding to the first voltage of the grid-side power supply during the compensation period.

[0020] Optionally, determining the insertion time based on the voltage compensation amount of the integral module at the insertion compensation end point includes:

[0021] A sinusoidal equivalent trajectory is generated based on the second voltage of the integration module, and the insertion time is determined by an inverse trigonometric function based on the voltage compensation amount.

[0022] Optionally, the dual active bridge converter further includes: an inductor module connected to the secondary coil of the transformer module; a primary bridge arm circuit connected between the input interface and the primary coil of the transformer module; and an integrator module connected between the secondary coil and the output terminal of the secondary bridge arm circuit, or the integrator module is connected in series with the current acquisition module of the inductor module.

[0023] Determining the insertion time based on the voltage compensation amount of the integral module at the end point of the insertion compensation includes:

[0024] A precise compensation trajectory is generated based on the second voltage of the integration module and the on / off state of the primary side bridge arm circuit. The insertion time is determined based on the difference between the voltage compensation amount and the voltage compensation threshold.

[0025] The voltage compensation threshold is the voltage value at the intersection of the first curve and the second curve in the compensation trajectory corresponding to the first voltage zero crossing point, where the voltage of the integration module and the current of the inductor module are respectively.

[0026] Optionally, the step of generating a precise compensation trajectory based on the second voltage of the integration module and the on / off state of the primary side bridge arm circuit, and determining the insertion time based on the difference between the voltage compensation amount and the voltage compensation threshold, includes:

[0027] When half of the voltage compensation amount is less than or equal to the maximum voltage compensation threshold, a sinusoidal equivalent trajectory is generated based on the second voltage of the integration module, and the insertion time is determined by an inverse trigonometric function based on the voltage compensation amount, and / or the insertion time is determined based on the equation of the first curve and the voltage compensation amount.

[0028] When half of the voltage compensation amount is greater than the voltage compensation threshold, the insertion time is determined according to the equation of the second curve, the voltage compensation amount, the voltage compensation threshold, and the maximum insertion time corresponding to the voltage compensation threshold.

[0029] Optionally, when half of the voltage compensation amount is greater than the voltage compensation threshold, determining the insertion time based on the equation of the second curve, the voltage compensation amount, the voltage compensation threshold, and the maximum insertion time corresponding to the voltage compensation threshold includes:

[0030] The first insertion time is determined based on the voltage compensation amount and the voltage compensation threshold.

[0031] Obtain the maximum insertion time corresponding to the voltage compensation threshold;

[0032] The insertion time is determined based on the maximum insertion time corresponding to the voltage compensation threshold and the first insertion time.

[0033] Optionally, the secondary bridge arm circuit includes: a first upper bridge arm transistor, a second upper bridge arm transistor, a first lower bridge arm transistor, a second lower bridge arm transistor, a first bus capacitor, and a second bus capacitor; the first upper bridge arm transistor and the second upper bridge arm transistor are connected between the first terminal of the energy storage output module and the first terminal of the secondary coil of the transformer module; the first lower bridge arm transistor and the second lower bridge arm transistor are connected between the second terminal of the second upper bridge arm transistor and the second terminal of the energy storage output module; the first bus capacitor is connected between the first terminal of the first upper bridge arm transistor and the second terminal of the integrating module; and the second bus capacitor is connected between the second terminal of the first bus capacitor and the second terminal of the second lower bridge arm transistor.

[0034] The step of controlling the conduction state of the secondary bridge arm circuit at the insertion compensation starting point, based on the insertion time, to adjust the average value of the output voltage of the energy storage output module to be continuous before and after the zero-crossing point of the first voltage, includes:

[0035] The first upper bridge arm transistor and the first lower bridge arm transistor are kept in the on state.

[0036] When the phase of the first current leads the phase of the first voltage, or is equal to the phase of the first voltage, at the starting point of the insertion compensation, the second lower bridge arm transistor is controlled to turn off and remain off for a duration equal to the insertion time, and the second upper bridge arm transistor is controlled to turn on and remain on for a duration equal to the insertion time, so as to adjust the average value of the output voltage of the energy storage output module to be continuous before and after the zero-crossing point of the first voltage.

[0037] The insertion compensation starting point is the compensation period of the second voltage corresponding to the zero-crossing moment of the first voltage, at the moment when the compensation period ends.

[0038] Optionally, after controlling the second lower bridge arm transistor to turn off and maintain the insertion time, and the second upper bridge arm transistor to turn on and maintain the insertion time, the process includes:

[0039] The second upper bridge arm transistor is turned off, and the second lower bridge arm transistor is turned on again.

[0040] Optionally, the secondary bridge arm circuit includes: a first upper bridge arm transistor, a second upper bridge arm transistor, a first lower bridge arm transistor, a second lower bridge arm transistor, a first bus capacitor, and a second bus capacitor; the first upper bridge arm transistor and the second upper bridge arm transistor are connected between the first terminal of the energy storage output module and the first terminal of the secondary coil of the transformer module; the first lower bridge arm transistor and the second lower bridge arm transistor are connected between the second terminal of the second upper bridge arm transistor and the second terminal of the energy storage output module; the first bus capacitor is connected between the first terminal of the first upper bridge arm transistor and the second terminal of the integrating module; and the second bus capacitor is connected between the second terminal of the first bus capacitor and the second terminal of the second lower bridge arm transistor.

[0041] The step of controlling the conduction state of the secondary bridge arm circuit at the insertion compensation starting point, based on the insertion time, to adjust the average value of the output voltage of the energy storage output module to be continuous before and after the zero-crossing point of the first voltage, includes:

[0042] The first upper bridge arm transistor and the first lower bridge arm transistor are kept in the on state.

[0043] When the phase of the first current lags behind the phase of the first voltage, at the start of the insertion compensation, the second lower bridge arm transistor is controlled to be turned on and kept on for a duration equal to the insertion time, so as to adjust the average value of the output voltage of the energy storage output module to be continuous before and after the zero-crossing point of the first voltage.

[0044] The starting point for the interpolation compensation is the zero-crossing point of the first voltage.

[0045] Optionally, after controlling the second lower bridge arm transistor to turn on and maintaining the insertion time, the following steps are included:

[0046] The second lower bridge arm transistor is turned off, and the second upper bridge arm transistor is turned on.

[0047] Optionally, the secondary bridge arm circuit includes: a first upper bridge arm transistor, a second upper bridge arm transistor, a first lower bridge arm transistor, a second lower bridge arm transistor, a first bus capacitor, and a second bus capacitor; the first upper bridge arm transistor and the second upper bridge arm transistor are connected between the first terminal of the energy storage output module and the second terminal of the secondary coil of the transformer module; the first lower bridge arm transistor and the second lower bridge arm transistor are connected between the second terminal of the second upper bridge arm transistor and the second terminal of the energy storage output module; the first bus capacitor is connected between the first terminal of the first upper bridge arm transistor and the second terminal of the integrating module; and the second bus capacitor is connected between the second terminal of the first bus capacitor and the second terminal of the second lower bridge arm transistor.

[0048] The step of controlling the conduction state of the secondary bridge arm circuit at the insertion compensation starting point, based on the insertion time, to adjust the average value of the output voltage of the energy storage output module to be continuous before and after the zero-crossing point of the first voltage, includes:

[0049] The first upper bridge arm transistor and the first lower bridge arm transistor are kept in the on state.

[0050] When the phase of the first current leads the phase of the first voltage, or is equal to the phase of the first voltage, at the starting point of the insertion compensation, the second lower bridge arm transistor is controlled to turn off and remain off for a duration equal to the insertion time, and the second upper bridge arm transistor is controlled to turn on and remain on for a duration equal to the insertion time, so as to adjust the average value of the output voltage of the energy storage output module to be continuous before and after the zero-crossing point of the first voltage, and adjust the average value of the first current to be continuous before and after the zero-crossing point of the first voltage.

[0051] The insertion compensation starting point is the compensation period of the second voltage corresponding to the zero-crossing point of the first voltage, and the time before the end of the compensation period is a first preset time interval.

[0052] According to another aspect of the present invention, an output voltage compensation device for a dual active bridge converter is provided, comprising:

[0053] The parameter acquisition module obtains the first voltage and first current of the grid-side power supply, and the second voltage and capacitance value of the integration module;

[0054] The starting point determination module is used to determine the start point of the plug-in compensation of the output voltage of the energy storage output module based on the zero-crossing time of the first voltage; the start point of the plug-in compensation is the target time after the zero-crossing time of the first voltage.

[0055] The compensation calculation module is used to determine the voltage compensation amount of the integration module at the end point of the insertion compensation based on the first voltage and first current of the grid-side power supply, the second voltage and capacitance value of the integration module, and the switching cycle of the switching module of the secondary bridge arm circuit.

[0056] The time calculation module is used to determine the insertion time based on the voltage compensation amount of the integral module at the end point of the insertion compensation.

[0057] The bridge arm control module is used to control the conduction state of the secondary bridge arm circuit at the insertion compensation starting point and the insertion time, so as to adjust the average value of the output voltage of the energy storage output module to be continuous before and after the zero crossing point of the first voltage.

[0058] According to another aspect of the present invention, a dual active bridge converter assembly is provided, comprising: a dual active bridge converter and an output voltage compensation device for the dual active bridge converter as described in any embodiment of the present invention.

[0059] The technical solution provided by this invention adjusts the output voltage of the energy storage output module by setting a compensation start point after the first voltage zero-crossing and adjusting the conduction state of the secondary bridge arm circuit at the compensation start point. Furthermore, by determining the compensation time, the average value of the energy storage output module's output voltage is made continuous before and after the first voltage zero-crossing, ensuring a small voltage difference between the average output voltage after zero-crossing and the first voltage, thus avoiding subsequent output voltage oscillations.

[0060] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0061] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying 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.

[0062] Figure 1 This is a flowchart of an output voltage compensation method for a dual active bridge converter according to an embodiment of the present invention;

[0063] Figure 2 This is a schematic diagram of a dual active bridge converter according to an embodiment of the present invention;

[0064] Figure 3 This is a schematic diagram of another dual active bridge converter provided according to an embodiment of the present invention;

[0065] Figure 4 It is a type of technology provided by existing technology Figure 2 The diagram shows the resonant waveform corresponding to the dual active bridge converter.

[0066] Figure 5 It is a type of technology provided by existing technology Figure 3 The diagram shows the non-resonant waveform corresponding to the dual active bridge converter.

[0067] Figure 6 This is a method provided according to embodiments of the present invention. Figure 2 The diagram shows the waveform after resonant compensation for the dual active bridge converter.

[0068] Figure 7 This is a method provided according to embodiments of the present invention. Figure 3 The diagram shows the waveform of the dual active bridge converter after non-resonant compensation.

[0069] Figure 8 This is a flowchart of another output voltage compensation method for a dual active bridge converter provided according to an embodiment of the present invention;

[0070] Figure 9 This is another method provided according to embodiments of the present invention. Figure 2 The diagram shows the waveform after resonant compensation for the dual active bridge converter.

[0071] Figure 10 It is a type of technology provided by existing technology Figure 2 The diagram shows the equivalent area of ​​the zero-crossing waveform corresponding to the dual active bridge converter.

[0072] Figure 11 This is yet another method provided according to embodiments of the present invention. Figure 2 The diagram shows the waveform after resonant compensation for the dual active bridge converter.

[0073] Figure 12 This is a method provided according to embodiments of the present invention. Figure 2 The diagram shows the sinusoidal equivalent trajectory of the dual active bridge converter.

[0074] Figure 13 This is a method provided according to embodiments of the present invention. Figure 2 The diagram shows the precise compensation trajectory corresponding to the dual active bridge converter.

[0075] Figure 14 This is yet another method provided according to embodiments of the present invention. Figure 2 The diagram shows the resonant waveform corresponding to the dual active bridge converter.

[0076] Figure 15 This is yet another method provided according to embodiments of the present invention. Figure 2 The diagram shows the resonant waveform corresponding to the dual active bridge converter.

[0077] Figure 16 This is yet another method provided according to embodiments of the present invention. Figure 2 The diagram shows the resonant waveform corresponding to the dual active bridge converter.

[0078] Figure 17 This is yet another method provided according to embodiments of the present invention. Figure 2 The diagram shows the resonant waveform of the dual active bridge converter. Detailed Implementation

[0079] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. 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 should fall within the scope of protection of the present invention.

[0080] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0081] This invention provides a method for compensating the output voltage of a dual active bridge converter. Figure 1 This is a flowchart illustrating an output voltage compensation method for a dual active bridge converter, as provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of a dual active bridge converter provided in an embodiment of the present invention. Figure 3 A schematic diagram of another dual active bridge converter provided in an embodiment of the present invention. See also... Figure 2 The dual active bridge converter includes: a primary-side bridge arm circuit 1, a transformer module 2, an inductor module 3, a secondary-side bridge arm circuit 4, an energy storage output module 5, and a grid-side power supply 6. The primary-side bridge arm circuit 1 is connected between the input interface and the primary coil of the transformer module 2; the secondary-side bridge arm circuit 4 is connected between the secondary coil of the transformer module 2 and the energy storage output module 5; the inductor module 3 is connected between the secondary coil and the input terminal of the secondary-side bridge arm circuit 4; the grid-side power supply 6 is connected in parallel with the energy storage output module 5. The dual active bridge converter also includes: an integrator module 7, which is connected between the secondary coil and the output terminal of the secondary-side bridge arm circuit.

[0082] Or see Figure 3 The integrator module 7 is connected in series with the current acquisition module Ls of the inductor module 3. The current of the inductor module 3 is sampled by the current acquisition module Ls and connected to a separate integrating capacitor Ci, which enables the measurement and control of the charge.

[0083] The primary-side bridge arm circuit includes a first bridge arm circuit 11 and a second bridge arm circuit 12. The first bridge arm circuit 11 and the second bridge arm circuit 12 are connected to the input interface, and the input capacitor... Connected in parallel with the first bridge arm circuit 11, the input interface is used to connect DC voltage. The output terminals of the first bridge arm circuit 11 and the second bridge arm circuit 12 are connected to the primary coil of the transformer module 2.

[0084] The first bridge arm circuit 11 includes a first transistor S1 and a second transistor S2, with the first terminal of the first transistor S1 connected to the input capacitor. The first terminal of the first transistor S1 is connected to the first terminal of the primary coil, and the second terminal of the second transistor S2 is connected to the second terminal of the first transistor S1. The second terminal of the second transistor S2 is connected to the input capacitor. The second terminal of the first transistor S1 is connected to the first terminal of the third transistor S3, the second terminal of the third transistor S3 is connected to the second terminal of the primary winding, the first terminal of the fourth transistor S4 is connected to the second terminal of the third transistor S3, and the second terminal of the fourth transistor S4 is connected to the second terminal of the second transistor S2. The transformer module 2 also includes a magnetizing inductor Lm, which is connected in parallel with the secondary winding. The inductor module 3 includes a secondary inductor Lr, the grid-side power supply 6 is connected in series with a grid-side inductor Lg, and the energy storage output module 5 includes an output capacitor Co.

[0085] For example, see [link to previous article] Figure 2 and Figure 3 The secondary bridge arm circuit 4 may include: a first upper bridge arm transistor S1H, a second upper bridge arm transistor S1L, a first lower bridge arm transistor S2L, a second lower bridge arm transistor S2H, a first bus capacitor C1, and a second bus capacitor C2; the first upper bridge arm transistor S1H and the second upper bridge arm transistor S1L are connected between the first terminal of the energy storage output module 5 and the second terminal of the inductor module 3, the first lower bridge arm transistor S2L and the second lower bridge arm transistor S2H are connected between the second terminal of the second upper bridge arm transistor S1L and the second terminal of the energy storage output module 5, the first bus capacitor C1 is connected between the first terminal of the first upper bridge arm transistor S1H and the second terminal of the integration module 7, and the second bus capacitor C2 is connected between the second terminal of the first bus capacitor C1 and the second terminal of the second lower bridge arm transistor S2H.

[0086] Figure 4 A kind of existing technology Figure 2 The diagram shows the resonant waveform of the dual active bridge converter. (Combined with...) Figure 2 and Figure 4The current in inductor module 3 is the inductor current ir, the voltage in integrator module 7 is the second voltage Vcr, the voltage in energy storage output module 5 is the output voltage Vo, and the voltage in grid-side power supply 6 is the first voltage Vg. Point X is the zero-crossing point of the first voltage Vg.

[0087] At time t0, before the first voltage Vg crosses zero, the first lower bridge arm transistor S2L is turned off, and the inductor current ir of inductor module 3 is positive. During the dead time, inductor module 3 discharges, and the inductor current ir flows through the junction capacitance of the first upper bridge arm transistor S1H, the first bus capacitor C1, the integrator module 7, and the transformer module 2. After the junction capacitance is completely discharged, the inductor current ir freewheels through the body diode of the first upper bridge arm transistor S1H, at which point the voltage on the first upper bridge arm transistor S1H is very low. After the dead time, the first upper bridge arm transistor S1H is turned on, achieving zero-voltage turn-on of the first upper bridge arm transistor S1H. Similarly, at time t1, the inductor current ir is negative, flowing through inductor module 3, transformer module 2, integrator module 7, second bus capacitor C2, and the junction capacitance of the first lower bridge arm transistor S2L, achieving zero-voltage turn-on of the first lower bridge arm transistor S2L.

[0088] When the first voltage Vg crosses zero and becomes negative, the first upper bridge arm transistor S1H and the first lower bridge arm transistor S2L become normally on, while the second upper bridge arm transistor S1L and the second lower bridge arm transistor S2H begin to conduct alternately. Since the amplitude of the first voltage Vg is very small, it has little effect on the resonant current waveform, and the waveforms and trends of the inductor current ir and the second voltage Vcr of the integrator module 7 remain unchanged. At the next switching moment t2, the inductor current ir is positive, and its direction is consistent with the direction of the body diode of the second lower bridge arm transistor S2H. At this time, conducting the second lower bridge arm transistor S2H can achieve zero-voltage conduction, while conducting the second upper bridge arm transistor S1L cannot achieve zero-voltage conduction. Therefore, after the voltage crosses zero, the second lower bridge arm transistor S2H will continue to conduct for a period of time before the second upper bridge arm transistor S1L and the second lower bridge arm transistor S2H alternately conduct, and the switching pattern in subsequent moments is the same as before the first voltage crosses zero.

[0089] However, during the zero-crossing switching process of the first voltage Vg, the waveform trend of the output voltage Vo is opposite before and after the first voltage Vg crosses zero; the voltage bulges before the zero-crossing and dips after the zero-crossing. This results in the average value of the output voltage Vo... Changes will occur before and after crossing zero, such as Figure 4 The waveform of the output voltage Vo is shown. At the same time, the total conduction time of the first lower bridge arm transistor S2L and the second lower bridge arm transistor S2H is much greater than half a cycle, that is, the first lower bridge arm transistor S2L and the second lower bridge arm transistor S2H are continuously conducted for a long time. This process will affect the reverse starting point of the output voltage Vo waveform after the voltage crosses zero.

[0090] Therefore, both of the above changes will cause a change in the output voltage Vo, and the average value of the output voltage Vo after crossing zero will also change. A large voltage difference is generated with the first voltage Vg. This causes subsequent output voltage Vo to oscillate, and also affects the output current waveform.

[0091] Figure 5 A kind of existing technology Figure 3 The diagram shows the non-resonant waveform of the dual active bridge converter. (Combined with...) Figure 3 and Figure 5 External integrating capacitor voltage The waveform is approximately triangular, similar to the above resonant waveform diagram. The output voltage Vo of the non-resonant waveform also has a discontinuous average value before and after crossing zero.

[0092] This invention provides a method for compensating the output voltage of a dual active bridge converter. Figure 6 A method provided by an embodiment of the present invention Figure 2 The diagram shows the waveform after resonant compensation for the dual active bridge converter. Figure 7 A method provided by an embodiment of the present invention Figure 3 The diagram shows the waveform of the dual active bridge converter after non-resonant compensation. (Combined with...) Figures 1 to 7 The output voltage compensation method for a dual active bridge converter includes:

[0093] S110, obtain the first voltage and first current of the grid-side power supply, and the second voltage and capacitance value of the integrator module.

[0094] The integration module may include a secondary capacitor Cr, and the second voltage and capacitance value of the integration module are the voltage and capacitance values ​​of the secondary capacitor Cr, respectively.

[0095] S120. Determine the start point of the plug-in compensation for the output voltage of the energy storage output module based on the zero-crossing time of the first voltage; the start point of the plug-in compensation is the target time after the zero-crossing time of the first voltage.

[0096] Among them, the average value of the output voltage Vo after the zero-crossing point of the first voltage Vg is... The voltage changes, and a large voltage difference is generated between the voltage and the first voltage Vg. Therefore, it is necessary to set the start point for the interpolation compensation after the zero-crossing point, and adjust the conduction mode of each transistor in the secondary bridge arm circuit 4 at the start point of the interpolation compensation, thereby adjusting the output voltage Vo.

[0097] For example, Figure 6 The starting point for the interpolation compensation is time t2. Figure 7 The starting point for the interpolation compensation is time t1'.

[0098] S130. Based on the first voltage and first current of the grid-side power supply, the second voltage and capacitance value of the integrator module, and the switching cycle of the switching module of the secondary bridge arm circuit, determine the voltage compensation amount of the integrator module at the end point of the interpolation compensation.

[0099] Among these, to ensure the average value of the output voltage Vo To ensure consistency with the first voltage Vg, a voltage compensation amount needs to be set to ensure that this compensation amount can accurately compensate for the average value of the output voltage Vo. The voltage difference between the first voltage Vg and the ... first voltage Vg .

[0100] The voltage compensation amount can be determined by the first voltage Vg and the first current Ig of the grid-side power supply, the second voltage Vcr and the capacitance value Cr of the integrator module, and the switching cycle of the switching module of the secondary bridge arm circuit.

[0101] S140. Determine the insertion time based on the voltage compensation amount of the integral module at the end point of the insertion compensation.

[0102] Once the voltage compensation amount is determined, the insertion time can be determined. The insertion time is the adjustment time for the output voltage Vo.

[0103] For example, Figure 6 The insertion time in the image is the time Δt between t2 and t2'. Figure 7 The insertion time in the middle is the time Δt' between t1' and t1”.

[0104] S150. At the start of the insertion compensation, control the conduction state of the secondary bridge arm circuit by the insertion time, so as to adjust the average value of the output voltage of the energy storage output module to be continuous before and after the zero-crossing point of the first voltage.

[0105] For example, when the average value of the output voltage Vo When the voltage is lower than the first voltage Vg, during the insertion time, the output voltage Vo will continuously increase by adjusting the conduction state of each transistor in the secondary bridge arm circuit 4, thereby increasing the average value of the output voltage Vo. The average value of the output voltage Vo is also continuously increasing. The voltage difference between the voltage and the first voltage Vg continuously decreases.

[0106] By continuously reducing the average value of the output voltage Vo The voltage difference between the voltage and the first voltage Vg will adjust the average value of the output voltage Vo of the energy storage output module to be continuous with the zero-crossing point of the first voltage Vg.

[0107] Combination Figure 2 , Figure 4 and Figure 6 After time t2, Figure 6 The output voltage Vo (the green curve portion between t2 and t3) is compared to Figure 4 The portion corresponding to the output voltage Vo increases, thereby adjusting the average value of the output voltage Vo to a state that is continuous with the zero-crossing moment of the first voltage Vg.

[0108] Combination Figure 3 , Figure 5 and Figure 7 After time t1', Figure 7 The output voltage Vo (between t1' and t1") is compared to Figure 5 The rise time of the output voltage Vo becomes longer, while the fall time of the output voltage Vo (between t1” and t2) becomes shorter. That is, between t1' and t2, Figure 7 The output voltage Vo in the middle is compared to Figure 5 The value of the output voltage Vo is higher, which in turn increases the average value of the output voltage Vo after the zero-crossing point of the first voltage Vg, so that the average value of the output voltage Vo is adjusted to be continuous with the time before and after the zero-crossing point of the first voltage Vg.

[0109] The above embodiment illustrates the situation with a negative power factor and the first voltage Vg changing from positive to negative after crossing zero. If the first voltage Vg changes from negative to positive after crossing zero, the calculation method is the same, but attention must be paid to the direction of charge compensation. The calculation process and compensation method for a positive power factor are similar to those for a negative power factor, and will not be elaborated upon here. Furthermore, the calculation methods for the insertion compensation starting point, voltage compensation amount, insertion time, etc., are completely consistent between resonant dual active bridge converters and non-resonant dual active bridge converters.

[0110] The technical solution provided by this invention adjusts the output voltage of the energy storage output module by setting a compensation start point after the first voltage zero-crossing and adjusting the conduction state of the secondary bridge arm circuit at the compensation start point. Furthermore, by determining the compensation time, the average value of the energy storage output module's output voltage is made continuous before and after the first voltage zero-crossing, ensuring a small voltage difference between the average output voltage after zero-crossing and the first voltage, thus avoiding subsequent output voltage oscillations.

[0111] Figure 8 A flowchart illustrating another output voltage compensation method for a dual active bridge converter provided in an embodiment of the present invention. (Combined with...) Figure 2 , Figure 6 and Figure 8Based on the above embodiments, optionally, S130, determining the voltage compensation amount of the integration module at the end point of the insertion compensation based on the first voltage and first current of the grid-side power supply, the second voltage and capacitance value of the integration module, and the switching cycle of the switching module of the secondary bridge arm circuit, may include:

[0112] S131. Based on the first voltage and first current of the grid-side power supply, the second voltage and capacitance value of the integrator module, and the switching cycle of the switching module of the secondary bridge arm circuit, determine the total charge amount to be compensated for the output voltage of the energy storage output module during the compensation period.

[0113] S132. Based on the total charge to be compensated in the output voltage and the capacitance value of the integrating module, determine the voltage compensation amount of the integrating module at the end point of the interpolation compensation.

[0114] For the dual active bridge converter, the insertion time needs to be calculated based on its operating state. For the dual active bridge converter, the inductor module 3 and the integrator module 7 can be considered as being in series.

[0115] The second voltage Vcr of the integrator module 7 can be divided into a low-frequency AC section and a high-frequency AC section. The low-frequency AC section is responsible for charging the energy storage output module 5 and providing low-frequency current output to the grid-side power supply 6. The high-frequency AC section affects the voltage ripple of the output energy storage output module 5. Therefore, there is a proportional relationship between the high-frequency voltage of the integrator module 7 and the high-frequency ripple voltage of the energy storage output module 5. By sampling the second voltage Vcr of the integrator module 7, calculating the required total charge, and performing interpolation compensation at the corresponding waveform, compensation for the output voltage Vo can be achieved.

[0116] The average value of the output voltage Vo after zero crossing The voltage difference between the first voltage Vg and the ... first voltage Vg It mainly consists of three aspects: First, the average value change caused by the waveform reversal of the output voltage Vo. Second, the impact of the amount of charge output by the energy storage output module 5 to the grid side on the output voltage Vo during the period from the first voltage Vg crossing zero and changing the switching logic to stable operation. Third, the natural decrease or increase in the voltage of the grid-side power supply 6 during the period when the switching logic changes at zero.

[0117] Figure 9 Another embodiment of the present invention Figure 2 The diagram shows the waveform after resonant compensation for the dual active bridge converter. (Combined with...) Figure 2 and Figure 9An additional second upper bridge arm transistor S1L is turned on at points A and B. During the period from point A to point B, the second voltage Vcr of the integrator module 7 changes to ΔVb. The charge flows positively through the inductor module 3, from the inductor module 3 to the first upper bridge arm transistor S1H and the second upper bridge arm transistor S1L, with a charge of Cr × ΔVb. Subsequently, the current flows from the upper end to the lower end of the energy storage output module 5, and the output voltage Vo increases positively by Vb1. During the period from point B to point C, the second voltage Vcr of the integrator module 7 changes to -ΔVb. The charge flows in the reverse direction through the inductor module 3, from the first lower bridge arm transistor S2L and the second lower bridge arm transistor S2H to the resonant cavity, with a charge of Cr × ΔVb. At this time, the current still flows from the upper end to the lower end of the energy storage output module 5, and the output voltage Vo increases positively by Vb2.

[0118] Therefore, in the compensation of the integrator module 7, the actual amount of charge compensated is twice the amount of charge corresponding to the voltage at the insertion point of the integrator module 7 during the insertion compensation period. That is, the total amount of charge to be compensated for at the output voltage of the energy storage output module is: ;

[0119] However, since the total charge is also affected by the second and third aspects mentioned above, the charge output by the integrator module 7 is not entirely added to the output capacitor Co of the energy storage output module 5. Therefore, the two voltage rises Vb1 and Vb2 of the output capacitor Co are not equal. To achieve correct compensation, it is necessary to calculate and sum based on the above three aspects to obtain the required voltage compensation amount ΔVb, thus achieving correct compensation. The following is a detailed explanation of these three aspects.

[0120] Based on the above embodiments, optionally, in step S131, the total charge amount to be compensated for by the output voltage of the energy storage output module during the compensation period is determined according to the first voltage and first current of the grid-side power supply, the second voltage and capacitance value of the integrator module, and the switching cycle of the switching module of the secondary bridge arm circuit, including:

[0121] Based on the second voltage of the integrator module, the capacitance value of the integrator module, and the switching cycle of the switching module of the secondary bridge arm circuit, the corresponding first charge amount of the integrator module during the compensation period is determined.

[0122] Figure 10 A kind of existing technology Figure 2 The diagram shows the equivalent area of ​​the zero-crossing waveform for the dual active bridge converter. (Combined with...) Figure 2 and Figure 10 After the first voltage Vg crosses zero under the condition of ensuring full-range soft switching operation, the voltage waveform of the output capacitor Co of the energy storage output module 5 flips. Near the zero-crossing point of the first voltage Vg, the average value of the high-frequency voltage of the resonant capacitor is approximated as the average value of the output capacitor voltage ripple, and compensation is made according to the voltage difference before and after.

[0123] For the dual active bridge converter, the output current corresponding to the change in the second voltage Vcr consists of two parts: one part is output to the grid-side power supply 6, and the other part flows through the output capacitor Co of the energy storage output module 5.

[0124] In the waveform of the second voltage Vcr, the voltage difference Δv corresponding to the dashed line connecting the voltage waveforms at the two switching moments, multiplied by the capacitance value of the secondary capacitor Cr, corresponds to the total charge Qcr output by the secondary capacitor Cr within half a cycle, which is also the charge corresponding to the first current Ig of the output grid-side power supply. The first current Ig is considered as a DC current during the high-frequency switching cycle, i.e.:

[0125] ;

[0126] Where Ts is one switching cycle and Cr is the capacitance value of the secondary capacitor.

[0127] From a transient perspective, the difference between the actual waveform of the second voltage Vcr and the dashed line connecting the switching moment corresponds to the change in current through the output capacitor Co within half a cycle, which in turn corresponds to the change in the output voltage Vo of the output capacitor. Therefore, after calculating the area Scr of the dashed line connecting the second voltage Vcr and the switching moment within half a cycle, dividing by half a cycle, we can obtain the average voltage of the excess portion, i.e.:

[0128] ;

[0129] The current in the excess portion of the resonant capacitor is equal to the current flowing through the output capacitor Co. Therefore, the average voltage of the excess portion of the resonant capacitor is... The voltage difference V1 between the average voltage of the output capacitor and the bottom slope is proportional, that is:

[0130] ;

[0131] Where Co is the capacitance value of the output capacitor.

[0132] To achieve voltage compensation for the output capacitor Co, the output charge of the secondary capacitor Cr can be effectively increased during the compensation period. The difference between the average output capacitor voltage before and after the switching is twice V1, i.e.:

[0133] ;

[0134] Therefore, the additional charge required for this secondary capacitor, which is also the corresponding first charge of the integration module, is:

[0135] .

[0136] Based on the first current of the grid-side power supply, determine the second charge quantity corresponding to the first current of the grid-side power supply during the compensation period.

[0137] The required first charge amount obtained in the above calculation This compensation only covers the voltage change caused by the switching of the output capacitor Co itself, without considering external conditions. During the compensation period, there is also charge transfer in the first current Ig. During high-frequency switching, the first current Ig can be considered as DC. If the first current Ig is positive, the grid side draws charge from the dual active bridge converter, requiring more charge compensation to maintain the stability of the output capacitor voltage Vo. If the first current Ig is negative, the grid side replenishes charge to the dual active bridge converter, and less charge compensation is needed to maintain the stability of the output capacitor voltage Vo.

[0138] Figure 11 Another embodiment provided by the present invention Figure 2 The diagram shows the waveform after resonant compensation for the dual active bridge converter. (Combined with...) Figure 2 and Figure 11 During the charge compensation period from t2 to t3, the first current Ig is negative, representing the charge supplied from the grid side to the dual active bridge converter. Defining the direction of charge withdrawal from the grid side as positive, the withdrawn charge can be expressed as:

[0139] ;

[0140] Among them, the first current Ig is negative, and the amount of charge drawn away Qg is also negative, representing the amount of charge provided by the grid side.

[0141] Therefore, the amount of charge required to compensate for this part is equal to the amount of charge removed from the grid side, that is, the second charge is:

[0142] ;

[0143] Where Qg is negative, then the second charge amount that needs to be compensated is... If the value is negative, the total amount of compensation required decreases.

[0144] Based on the first voltage of the grid-side power supply, determine the third charge quantity corresponding to the first voltage of the grid-side power supply during the compensation period.

[0145] Among them, continue to combine Figure 2 and Figure 11 The purpose of charge compensation is to ensure the average voltage of the output capacitor Co. Follow the first voltage Vg. During the compensation period from start to finish, the first voltage Vg will naturally decrease (or increase). Therefore, the output voltage Vo is not constant before and after compensation and needs to be adjusted to follow the change in the first voltage Vg. Therefore, when calculating the compensation charge, the charge amount of the decrease in the first voltage Vg needs to be subtracted to ensure that the compensated output voltage Vo follows the first voltage Vg.

[0146] During the charge compensation period t2-t3, the natural change in the first voltage Vg can be expressed as:

[0147] ;

[0148] in, This is the first voltage at time t3. The first voltage at time t2, This indicates that the first voltage has decreased. The corresponding third charge is:

[0149] ;

[0150] In summary, the total charge to be compensated for during the compensation period is the sum of the first charge, the second charge, and the third charge, i.e.:

[0151] ;

[0152] The voltage compensation amount of the integral module at the end point of the interpolation compensation is:

[0153] ;

[0154] This yields the voltage value of the integral module corresponding to the timing of the insertion compensation. Therefore, the voltage compensation amount is reached at the second voltage Vcr. When interpolation compensation is performed, continuous voltage zero-crossing points can be achieved.

[0155] The technical solution provided by the embodiments of the present invention achieves accurate acquisition of the total charge by calculating the first charge, the second charge, and the third charge respectively, thereby achieving accurate calculation of the voltage compensation amount and having a good compensation effect.

[0156] Figure 12 A method provided by an embodiment of the present invention Figure 2 The diagram shows the sinusoidal equivalent trajectory of the dual active bridge converter. (Combined with...) Figure 2 and Figure 12Based on the above embodiments, optionally, the insertion time is determined according to the voltage compensation amount of the integration module at the end point of the insertion compensation, including: generating a sinusoidal equivalent trajectory based on the second voltage of the integration module, and determining the insertion time by an inverse trigonometric function based on the voltage compensation amount.

[0157] in, Figure 12 The diagram shows the magnitudes of the second voltage Vcr and inductor current ir when different transistors in the primary and secondary bridge arm circuits are turned on or off. -nVin-Vo, -Vo, and nVin-Vo are the voltages across the resonant cavity formed by the integrator module and the inductor module.

[0158] The second voltage Vcr of the integrator module can be equivalent to a sine wave. Based on the voltage compensation amount ΔVb of the integrator module at the end of the interpolation compensation, the interpolation time Δt is solved using inverse trigonometric functions, thereby achieving interpolation compensation. The sine equivalent method is simple to calculate and has a relatively fast calculation speed.

[0159] Figure 12 The brown dashed line in the diagram represents the sinusoidal equivalent trajectory. Taking half a cycle as an example, when using the sinusoidal equivalent, if the voltage compensation amount ΔVb is small and the insertion point is in region 1 (QY1), such as point a, the compensation error is small and the compensation result is accurate. If the voltage compensation amount ΔVb is large and the insertion point falls in region 2 (QY2), such as point a', then there is a large error ΔV' between the sinusoidal equivalent result and the actual compensation voltage. In this case, the compensation effect is larger and the effect is poor. Therefore, to achieve a better compensation effect, a precise compensation calculation method is needed, which will be explained in detail below.

[0160] Figure 13 A method provided by an embodiment of the present invention Figure 2 The diagram shows the precise compensation trajectory corresponding to the dual active bridge converter. Combined with... Figure 2 and Figure 13 Based on the above embodiments, optionally, the insertion time is determined according to the voltage compensation amount of the integrating module at the insertion compensation end point, including: generating a precise compensation trajectory based on the second voltage of the integrating module and the on / off state of the primary bridge arm circuit, and determining the insertion time based on the difference between the voltage compensation amount and the voltage compensation threshold. The voltage compensation threshold is the voltage value corresponding to the intersection of the first curve and the second curve in the compensation trajectory corresponding to the first voltage zero-crossing point, where the voltage of the integrating module and the current of the inductor module intersect.

[0161] Among them, the curve in region 1 (QY1) is the first curve, and the curve in region 2 (QY2) is the second curve. Based on the difference between the voltage compensation amount and the voltage compensation threshold, the insertion time can be determined by generating a precise compensation trajectory.

[0162] Optionally, a precise compensation trajectory is generated based on the second voltage of the integrator module and the on / off state of the primary bridge arm circuit. The insertion time is determined based on the difference between the voltage compensation amount and the voltage compensation threshold, including:

[0163] When half the voltage compensation is less than or equal to the maximum voltage compensation threshold, a sinusoidal equivalent trajectory is generated based on the second voltage of the integrator module. The insertion time is determined by an inverse trigonometric function based on the voltage compensation, and / or by the equation of the first curve and the voltage compensation. When half the voltage compensation is greater than the voltage compensation threshold, the insertion time is determined based on the equation of the second curve, the voltage compensation, the voltage compensation threshold, and the maximum insertion time corresponding to the voltage compensation threshold.

[0164] Specifically, when half the voltage compensation is less than or equal to the maximum voltage compensation threshold V1max, the insertion point is located in region 1 (QY1). In this case, the insertion time Δt can be determined by the equation of the first curve and the voltage compensation. Furthermore, determining the insertion time Δt through the sinusoidal equivalent trajectory also has good accuracy.

[0165] When the voltage compensation amount is half greater than the maximum voltage compensation threshold, the insertion point is located in region 2 (QY2). At this time, the sinusoidal equivalent trajectory has a large error. Therefore, the insertion time Δt can be calculated using the precise compensation trajectory. The insertion time Δt can be determined by combining the equation of the second curve, the voltage compensation amount, the voltage compensation threshold, and the maximum insertion time corresponding to the voltage compensation threshold.

[0166] Optionally, when half the voltage compensation amount is greater than the voltage compensation threshold, the insertion time is determined based on the equation of the second curve, the voltage compensation amount, the voltage compensation threshold, and the maximum insertion time corresponding to the voltage compensation threshold. This includes: determining the first insertion time based on the voltage compensation amount and the voltage compensation threshold; obtaining the maximum insertion time corresponding to the voltage compensation threshold; and determining the insertion time based on the maximum insertion time corresponding to the voltage compensation threshold and the first insertion time.

[0167] Specifically, by jointly solving the equation of the second curve and ΔVb / 2-V1max, the insertion time in region 2 (QY2), i.e., the first insertion time, can be determined. This insertion time does not include the insertion time in region 1 (QY1). Therefore, it is also necessary to obtain the maximum insertion time corresponding to the voltage compensation threshold. The maximum insertion time is the maximum insertion time in region 1 (QY1). By adding the maximum insertion time to the first insertion time, the total insertion time can be obtained.

[0168] This invention calculates the insertion time using either a sinusoidal equivalent trajectory or a precise compensation trajectory. Using the sinusoidal equivalent trajectory simplifies the calculation process. Distinguishing between different regions of the compensation point and calculating the insertion time using a precise compensation trajectory improves the accuracy of the calculation and provides a better compensation effect.

[0169] Continue to combine Figure 2 and Figure 11 Based on the above embodiments, optionally, in step S150, controlling the conduction state of the secondary bridge arm circuit at the insertion compensation starting point by an insertion time to adjust the average value of the output voltage of the energy storage output module to be continuous before and after the zero-crossing point of the first voltage includes: controlling the first upper bridge arm transistor and the first lower bridge arm transistor to remain in the conducting state. When the phase of the first current leads the phase of the first voltage, or is equal to the phase of the first voltage, at the insertion compensation starting point, controlling the second lower bridge arm transistor to turn off and remain off for a duration equal to the insertion time, and the second upper bridge arm transistor to turn on and remain on for a duration equal to the insertion time, to adjust the average value of the output voltage of the energy storage output module to be continuous before and after the zero-crossing point of the first voltage. The insertion compensation starting point is the compensation period of the second voltage corresponding to the zero-crossing point of the first voltage, at the end of the compensation period.

[0170] When the phase of the first current Ig leads the phase of the first voltage Vg, or is equal to the phase of the first voltage Vg, the second upper bridge arm transistor S1L is turned on once more during the period from t2 to t2' after the long conduction period of the second lower bridge arm transistor S2H, and the second lower bridge arm transistor S2H is turned off. The conduction time of the second upper bridge arm transistor S1L is the insertion time Δt. Figure 11 The example shows that time t2 represents the turn-on time of the second upper bridge arm transistor S1L. In this embodiment, t2 is the start point of the interpolation compensation.

[0171] The above compensation can raise the endpoint of the output voltage Vo (corresponding to the green voltage waveform), so that after the first voltage Vg crosses zero, the average value of the output voltage Vo is continuous with that before the zero crossing, avoiding output disturbances. That is, one time-interpolation compensation is performed.

[0172] Continue to combine Figure 2 and Figure 11 Based on the above embodiments, optionally, after controlling the second lower bridge arm transistor to turn off and maintain the insertion time, and the second upper bridge arm transistor to turn on and maintain the insertion time, the method includes: controlling the second upper bridge arm transistor to turn off, and the second lower bridge arm transistor to return to the on state.

[0173] Specifically, after the second upper bridge arm transistor S1L is turned on and held for a time interval Δt, the average value of the output voltage Vo is continuous with the value before zero crossing. At this time, the second lower bridge arm transistor S2H can continue to be turned on, while the second upper bridge arm transistor S1L is turned off. The second upper bridge arm transistor S1L and the first lower bridge arm transistor S2L remain on, so that the waveform of the output voltage Vo returns to its original state.

[0174] Figure 14 Another type of technology provided by the prior art Figure 2 The diagram shows the resonant waveform of the dual active bridge converter. Figure 15 Another embodiment provided by the present invention Figure 2 The diagram shows the resonant waveform of the dual active bridge converter. (Combined with...) Figure 2 , Figure 14 and Figure 15 Based on the above embodiments, optionally, at the start of the insertion compensation, the conduction state of the secondary bridge arm circuit is controlled by the insertion time to adjust the average value of the output voltage of the energy storage output module to be continuous before and after the zero-crossing point of the first voltage. This includes: controlling the first upper bridge arm transistor and the first lower bridge arm transistor to remain in the conducting state. When the phase of the first current lags behind the phase of the first voltage, at the start of the insertion compensation, the second lower bridge arm transistor is controlled to conduct and remain conducting for the insertion time to adjust the average value of the output voltage of the energy storage output module to be continuous before and after the zero-crossing point of the first voltage. The start of the insertion compensation is the zero-crossing point of the first voltage.

[0175] See Figure 14 When the phase of the first current lags behind the phase of the first voltage, the polarity of the first voltage Vg changes after it crosses zero, altering the soft-switching conditions of the secondary bridge arm circuit. To achieve soft switching, the phase shift angle between the primary and secondary coils of transformer module 2 needs to be changed. This is achieved by altering the current direction corresponding to the conduction of each transistor in the secondary bridge arm circuit, thus realizing zero-voltage switching. However, changing the phase shift angle causes the conduction time of the first upper bridge arm transistor S1H and the second upper bridge arm transistor S1L (or the first lower bridge arm transistor S2L and the second lower bridge arm transistor S2H) to be less than half a cycle.

[0176] Therefore, after the first voltage Vg crosses zero, due to the phase shift adjustment, the waveform trend of the output voltage Vo reverses. Furthermore, the conduction time of the lower bridge arm corresponding to the first lower bridge arm transistor S2L is short, and the amount of charge flowing through the lower bridge arm differs from the normal operating cycle, causing a change in the starting point of the output voltage Vo. Compensation is required, and different interpolation compensation starting points need to be set. Specifically, as follows... Figure 15 As shown.

[0177] See Figure 15After the first voltage Vg crosses zero, the second lower bridge arm transistor S2H is turned on once more before the second upper bridge arm transistor S1L turns on. The turn-on time is the interpolation time Δt', and interpolation compensation is performed. The above compensation can raise the endpoint of the output voltage Vo (corresponding to the green voltage waveform), so that after the first voltage Vg crosses zero, the average value of the output voltage Vo is continuous with that before the zero crossing, avoiding output disturbances. Figure 15 The example shows that time t1' represents the turn-on time of the second lower bridge arm transistor S2H. In this embodiment, t1' is the start point of the interpolation compensation.

[0178] Continue to combine Figure 2 and Figure 15 Based on the above embodiments, optionally, after controlling the second lower bridge arm transistor to turn on and maintaining the insertion time, the method includes: controlling the second lower bridge arm transistor to turn off and the second upper bridge arm transistor to turn on.

[0179] Specifically, after the second lower bridge arm transistor S2H is turned on and held for the insertion time Δt', the average value of the output voltage Vo is continuous with that before zero crossing. At this time, the second upper bridge arm transistor S1L can be turned on, and the second lower bridge arm transistor S2H can be turned off. The second upper bridge arm transistor S1L and the first lower bridge arm transistor S2L remain on, so that the waveform of the output voltage Vo is restored to its original state.

[0180] Figure 16 Another embodiment provided by the present invention Figure 2 The diagram shows the resonant waveform of the dual active bridge converter. (Combined with...) Figure 2 and Figure 16 If adopted with Figure 11 Using the exact same compensation method ensures that the average value of the output voltage Vo before and after compensation is equal and continuous. However, before and after compensation, the waveform of the output voltage Vo reverses, causing a change in the volt-second product of the first current Ig, which in turn leads to a shift in the average value of the first current Ig.

[0181] The output voltage Vo remains continuous after compensation, but the first current Ig is affected by the inversion of the Vo waveform. The deviation in the average value causes the initial value of the first current Ig to change, while the circuit output reference current Iref (desired output current) remains unchanged in the short term. The average value of the first current Ig is discontinuous. During the subsequent stabilization process, the first current Ig is not equal to the reference current Iref, and the system will still oscillate to a certain extent until it reaches a stable state again.

[0182] To achieve optimal compensation, the average value of the first current Ig should be compensated simultaneously, ensuring that the average value of the first current Ig waveform remains continuous before and after the voltage waveform flips. The output voltage Vo waveform during compensation can be adjusted by further changing the start and end points of the voltage compensation switch. Due to inductance characteristics, the first current Ig equals the volt-second product of the output voltage Vo, thus affecting the waveform of the first current Ig and ultimately ensuring that the average value of the first current Ig remains continuous before and after zero crossing. The specific implementation method is as follows:

[0183] Figure 17 Another embodiment provided by the present invention Figure 2 The diagram shows the resonant waveform of the dual active bridge converter. (Combined with...) Figure 2 and Figure 17 At the start of the insertion compensation, with an insertion time Δt, the conduction state of the secondary bridge arm circuit is controlled to adjust the average value of the output voltage of the energy storage output module to be continuous before and after the zero-crossing point of the first voltage. This includes: controlling the first upper bridge arm transistor and the first lower bridge arm transistor to remain in the conducting state; when the phase of the first current leads the phase of the first voltage, or is equal to the phase of the first voltage, at the start of the insertion compensation, controlling the second lower bridge arm transistor to turn off and maintain the insertion time, and the second upper bridge arm transistor to turn on and maintain the insertion time, so as to adjust the first current and the voltage boost of the energy storage output module; wherein, the start of the insertion compensation is after the zero-crossing point of the first voltage and before the end of the current voltage cycle of the second voltage.

[0184] In this scheme, the waveform of the output voltage Vo is adjusted by further adjusting the positions of A and B at the insertion switch time, so that the total output charge remains unchanged during the compensation period. Figure 17 The example shows that time t2 represents the turn-on time of the second upper bridge arm transistor S1L. In this embodiment, t2 is the start point of the interpolation compensation.

[0185] While ensuring the voltage difference between points A and B remains constant at ΔVb (ΔVb corresponds to the required voltage compensation calculated using the previous method), and given -ΔVb1 - ΔVb2 = -ΔVb, the voltage difference (i.e., the total charge to be compensated) when the upper bridge arm is conducting (during the conduction of the second upper bridge arm transistor S1L) is ΔVb, and the sum of the voltage differences (i.e., the total charge to be compensated) when the lower bridge arm is conducting (during the conduction of the first lower bridge arm transistor S2L and the second lower bridge arm transistor S2H) is also -ΔVb. Figure 16The compensation amount is the same, ensuring that the output charge remains constant during the compensation period. Simultaneously, the positions of points A and B on the resonant voltage waveform are changed (i.e., the switching times of the second lower bridge arm transistor S2H and the second upper bridge arm transistor S1L are adjusted), thus adjusting the output voltage Vo waveform during the compensation period, as shown in the green section. Compared to the original compensation method, the above scheme compensates for Vb1, Vb2, and Vb3 respectively. The average value of the output voltage Vo increases during the compensation period, therefore the volt-second product of the output voltage Vo also increases (corresponding to an increase in the average value of the first current Ig). The average value of the first current Ig is equal and continuous before and after compensation. This method is equivalent to... Figure 16 Based on this, the timing of the insertion compensation start point is advanced, which allows for further compensation of the first current Ig on top of the compensated output voltage Vo, thereby minimizing the oscillation of the output current.

[0186] This invention also provides an output voltage compensation device for a dual active bridge converter. The output voltage compensation device for the dual active bridge converter includes:

[0187] The parameter acquisition module obtains the first voltage and first current of the grid-side power supply, and the second voltage and capacitance value of the integration module.

[0188] The starting point determination module is used to determine the start point of the plug-in compensation of the output voltage of the energy storage output module based on the zero-crossing time of the first voltage; the start point of plug-in compensation is the target time after the zero-crossing time of the first voltage.

[0189] The compensation calculation module is used to determine the voltage compensation amount of the integration module at the end point of the interpolation compensation based on the first voltage and first current of the grid-side power supply, the second voltage and capacitance value of the integration module, and the switching cycle of the switching module of the secondary bridge arm circuit.

[0190] The time calculation module is used to determine the insertion time based on the voltage compensation amount of the integral module at the end point of the insertion compensation.

[0191] The bridge arm control module is used to control the conduction state of the secondary bridge arm circuit at the start of the insertion compensation and the insertion time, so as to adjust the average value of the output voltage of the energy storage output module continuously before and after the zero crossing point of the first voltage.

[0192] The compensation calculation module is also used to determine the total charge amount to be compensated for the output voltage of the energy storage output module during the compensation period, based on the first voltage and first current of the grid-side power supply, the second voltage and capacitance value of the integrator module, and the switching cycle of the switching module of the secondary bridge arm circuit. Based on the total charge amount to be compensated for the output voltage and the capacitance value of the integrator module, the voltage compensation amount of the integrator module at the end of the interpolation compensation is determined.

[0193] The compensation calculation module is also used to determine the first charge amount of the integral module during the compensation period based on the second voltage of the integral module, the capacitance value of the integral module, and the switching cycle of the switching module of the secondary bridge arm circuit; to determine the second charge amount corresponding to the first current of the grid-side power supply during the compensation period based on the first current of the grid-side power supply; and to determine the third charge amount corresponding to the first voltage of the grid-side power supply during the compensation period based on the first voltage of the grid-side power supply.

[0194] The time calculation module is also used to generate a sinusoidal equivalent trajectory based on the second voltage of the integration module, and to determine the insertion time using an inverse trigonometric function based on the voltage compensation amount.

[0195] The time calculation module is also used to generate a precise compensation trajectory based on the second voltage of the integration module and the on / off state of the primary side bridge arm circuit, and to determine the insertion time based on the difference between the voltage compensation amount and the voltage compensation threshold.

[0196] The time calculation module is also used to determine the insertion time based on the second voltage generated by the integration module when the half-voltage compensation amount is less than or equal to the maximum voltage compensation threshold, using an inverse trigonometric function based on the voltage compensation amount, and / or, based on the equation of the first curve and the voltage compensation amount. When the half-voltage compensation amount is greater than the voltage compensation threshold, the insertion time is determined based on the equation of the second curve, the voltage compensation amount, the voltage compensation threshold, and the maximum insertion time corresponding to the voltage compensation threshold.

[0197] The time calculation module is also used to determine the first insertion time based on the voltage compensation amount and the voltage compensation threshold; obtain the maximum insertion time corresponding to the voltage compensation threshold; and determine the insertion time based on the maximum insertion time corresponding to the voltage compensation threshold and the first insertion time.

[0198] The bridge arm control module is also used to control the first upper bridge arm transistor and the first lower bridge arm transistor to remain in the on state; when the phase of the first current leads the phase of the first voltage or is equal to the phase of the first voltage, at the start of the insertion compensation, the second lower bridge arm transistor is controlled to turn off and maintain the insertion time, and the second upper bridge arm transistor is turned on and maintains the insertion time, so as to adjust the voltage boost of the energy storage output module.

[0199] The bridge arm control module is also used to control the second upper bridge arm transistor to turn off and the second lower bridge arm transistor to turn on.

[0200] The bridge arm control module is also used to control the first upper bridge arm transistor and the first lower bridge arm transistor to remain in the conducting state; when the phase of the first current lags behind the phase of the first voltage, at the start of the insertion compensation, the second lower bridge arm transistor is controlled to be turned on and kept in the insertion time to adjust the voltage boost of the energy storage output module.

[0201] The bridge arm control module is also used to control the second lower bridge arm transistor to turn off and the second upper bridge arm transistor to turn on.

[0202] The bridge arm control module is also used to control the first upper bridge arm transistor and the first lower bridge arm transistor to remain in the on state; when the phase of the first current leads the phase of the first voltage or is equal to the phase of the first voltage, at the start of the insertion compensation, the second lower bridge arm transistor is controlled to turn off and maintain the insertion time, and the second upper bridge arm transistor is turned on and maintains the insertion time, so as to adjust the voltage boost of the first current and the energy storage output module.

[0203] This invention also provides a dual active bridge converter assembly. The dual active bridge converter assembly includes a dual active bridge converter and an output voltage compensation device for the dual active bridge converter provided in any embodiment of this invention. It possesses similar beneficial effects to the output voltage compensation device for the dual active bridge converter, and will not be described in detail here.

[0204] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0205] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method of output voltage compensation for a dual active bridge converter, characterized in that, The dual active bridge converter includes: primary side bridge arm circuit (1), transformer module (2), secondary side bridge arm circuit (4), energy storage output module (5), grid-side power supply (6), and an integration module (7) connected to the secondary side coil of the transformer module (2). The method includes: The first voltage (Vg) and first current (ig) of the grid-side power supply are obtained, and the second voltage (Vg) of the integration module is obtained. ) and capacitance value (Cr); Based on the zero-crossing time of the first voltage (Vg), the start point for the interpolation compensation of the output voltage of the energy storage output module is determined; Based on the first voltage (Vg) and first current (ig) of the grid-side power supply, the second voltage of the integrating module ( The voltage compensation amount (ΔVb) of the integral module at the end point of the insertion compensation is determined by the voltage (Cr) and the switching cycle of the switching module of the secondary bridge arm circuit. The insertion time (Δt) is determined based on the voltage compensation amount (ΔVb) of the integral module at the end point of the insertion compensation. At the starting point of the insertion compensation, the conduction state of the secondary bridge arm circuit is controlled by the insertion time (Δt) to adjust the average value of the output voltage of the energy storage output module to be continuous before and after the zero-crossing point of the first voltage.

2. The output voltage compensation method of a dual active bridge converter according to claim 1, characterized in that, The secondary bridge arm circuit (4) is connected between the secondary coil of the transformer module (2) and the energy storage output module (5), and the grid-side power supply (6) is connected in parallel with the energy storage output module (5); The second voltage (Vg) of the integrator module is determined based on the first voltage (Vg) and first current (ig) of the grid-side power supply. The voltage compensation amount (ΔVb) of the integral module at the end point of the insertion compensation is determined by considering the capacitance value (Cr) and the switching cycle of the switching module of the secondary bridge arm circuit, including: Based on the first voltage (Vg) and first current (ig) of the grid-side power supply, the second voltage of the integrating module ( The total charge to be compensated during the compensation period is determined by considering the capacitance value (Cr) and the switching cycle of the switching module of the secondary bridge arm circuit, as well as the output voltage of the energy storage output module. ); Based on the total charge to be compensated in the output voltage and the capacitance value of the integration module, the voltage compensation amount (ΔVb) of the integration module at the end point of the interpolation compensation is determined.

3. The output voltage compensation method for a dual active bridge converter according to claim 2, characterized in that, The second voltage (Vg) of the integrator module is determined based on the first voltage (Vg) and first current (ig) of the grid-side power supply. The total charge to be compensated during the compensation period is determined by considering the capacitance value (Cr) and the switching cycle of the switching module of the secondary bridge arm circuit, as well as the output voltage of the energy storage output module. ),include: According to the second voltage of the integration module ( The first charge quantity of the integrator during the compensation period is determined by using the capacitance value (Cr) of the integrator module and the switching cycle of the switching module of the secondary bridge arm circuit, as well as the capacitance value (Cr) of the integrator module. ); Based on the first current (ig) of the grid-side power supply, determine the second charge quantity corresponding to the first current (ig) of the grid-side power supply during the compensation period. ); Based on the first voltage (Vg) of the grid-side power supply, determine the third charge quantity corresponding to the first voltage (Vg) of the grid-side power supply during the compensation period. ).

4. The output voltage compensation method for a dual active bridge converter according to claim 1, characterized in that, The step of determining the insertion time (Δt) based on the voltage compensation amount (ΔVb) of the integral module at the end point of the insertion compensation includes: The sinusoidal equivalent trajectory is generated based on the second voltage of the integration module, and the insertion time is determined by the inverse trigonometric function based on the voltage compensation amount (ΔVb).

5. The output voltage compensation method for a dual active bridge converter according to claim 1 or 4, characterized in that, The dual active bridge converter further includes: an inductor module (3) connected to the secondary coil of the transformer module (2); a primary bridge arm circuit (1) connected between the input interface and the primary coil of the transformer module (2); and an integrator module (7) connected between the secondary coil and the output terminal of the secondary bridge arm circuit (4), or the integrator module (7) connected in series with the current acquisition module of the inductor module (3). The step of determining the insertion time (Δt) based on the voltage compensation amount (ΔVb) of the integral module at the end point of the insertion compensation includes: A precise compensation trajectory is generated based on the second voltage of the integration module and the on / off state of the primary side bridge arm circuit. The insertion time (Δt) is determined based on the difference between the voltage compensation amount (ΔVb) and the voltage compensation threshold. The voltage compensation threshold is the voltage value at the intersection of the first curve and the second curve in the compensation trajectory corresponding to the first voltage zero crossing point, where the voltage of the integration module and the current of the inductor module are respectively.

6. The output voltage compensation method for a dual active bridge converter according to claim 5, characterized in that, The step of generating a precise compensation trajectory based on the second voltage of the integration module and the on / off state of the primary side bridge arm circuit, and determining the insertion time based on the difference between the voltage compensation amount and the voltage compensation threshold, includes: When half of the voltage compensation amount (ΔVb) is less than or equal to the maximum voltage compensation threshold, a sinusoidal equivalent trajectory is generated based on the second voltage of the integration module, and the insertion time (Δt) is determined by an inverse trigonometric function based on the voltage compensation amount (ΔVb), and / or the insertion time (Δt) is determined based on the equation of the first curve and the voltage compensation amount. When half of the voltage compensation amount (ΔVb) is greater than the voltage compensation threshold, the insertion time (Δt) is determined according to the equation of the second curve, the voltage compensation amount (ΔVb), the voltage compensation threshold, and the maximum insertion time corresponding to the voltage compensation threshold.

7. The output voltage compensation method for a dual active bridge converter according to claim 6, characterized in that, When half of the voltage compensation amount (ΔVb) is greater than the voltage compensation threshold, the insertion time (Δt) is determined based on the equation of the second curve, the voltage compensation amount (ΔVb), the voltage compensation threshold, and the maximum insertion time corresponding to the voltage compensation threshold, including: The first insertion time is determined based on the voltage compensation amount and the voltage compensation threshold. Obtain the maximum insertion time corresponding to the voltage compensation threshold; The insertion time is determined based on the maximum insertion time corresponding to the voltage compensation threshold and the first insertion time.

8. The output voltage compensation method for a dual active bridge converter according to claim 1, characterized in that, The secondary bridge arm circuit includes: a first upper bridge arm transistor (S1H), a second upper bridge arm transistor (S1L), a first lower bridge arm transistor (S2L), a second lower bridge arm transistor (S2H), a first bus capacitor (C1), and a second bus capacitor (C2); the first upper bridge arm transistor and the second upper bridge arm transistor are connected between the first terminal of the energy storage output module and the first terminal of the secondary coil of the transformer module; the first lower bridge arm transistor and the second lower bridge arm transistor are connected between the second terminal of the second upper bridge arm transistor and the second terminal of the energy storage output module; the first bus capacitor is connected between the first terminal of the first upper bridge arm transistor and the second terminal of the integrating module; and the second bus capacitor is connected between the second terminal of the first bus capacitor and the second terminal of the second lower bridge arm transistor. The step of controlling the conduction state of the secondary bridge arm circuit at the insertion compensation starting point by an insertion time (Δt) to adjust the average value of the output voltage of the energy storage output module to be continuous before and after the zero-crossing point of the first voltage includes: The first upper bridge arm transistor and the first lower bridge arm transistor are kept in the on state. When the phase of the first current leads the phase of the first voltage, or is equal to the phase of the first voltage, at the starting point of the insertion compensation, the second lower bridge arm transistor is controlled to turn off and remain off for a duration equal to the insertion time, and the second upper bridge arm transistor is controlled to turn on and remain on for a duration equal to the insertion time, so as to adjust the average value of the output voltage of the energy storage output module to be continuous before and after the zero-crossing point of the first voltage. The insertion compensation starting point is the compensation period of the second voltage corresponding to the zero-crossing moment of the first voltage, at the moment when the compensation period ends.

9. The output voltage compensation method for a dual active bridge converter according to claim 8, characterized in that, After controlling the second lower bridge arm transistor to turn off and maintain the insertion time, and the second upper bridge arm transistor to turn on and maintain the insertion time, the process includes: The second upper bridge arm transistor is turned off, and the second lower bridge arm transistor is turned on again.

10. The output voltage compensation method for a dual active bridge converter according to claim 1, characterized in that, The secondary bridge arm circuit includes: a first upper bridge arm transistor (S1H), a second upper bridge arm transistor (S1L), a first lower bridge arm transistor (S2L), a second lower bridge arm transistor (S2H), a first bus capacitor (C1), and a second bus capacitor (C2); the first upper bridge arm transistor and the second upper bridge arm transistor are connected between the first terminal of the energy storage output module and the first terminal of the secondary coil of the transformer module; the first lower bridge arm transistor and the second lower bridge arm transistor are connected between the second terminal of the second upper bridge arm transistor and the second terminal of the energy storage output module; the first bus capacitor is connected between the first terminal of the first upper bridge arm transistor and the second terminal of the integrating module; and the second bus capacitor is connected between the second terminal of the first bus capacitor and the second terminal of the second lower bridge arm transistor. The step of controlling the conduction state of the secondary bridge arm circuit at the insertion compensation starting point by an insertion time (Δt) to adjust the average value of the output voltage of the energy storage output module to be continuous before and after the zero-crossing point of the first voltage includes: The first upper bridge arm transistor and the first lower bridge arm transistor are kept in the on state. When the phase of the first current lags behind the phase of the first voltage, at the start of the insertion compensation, the second lower bridge arm transistor is controlled to be turned on and kept on for a duration equal to the insertion time, so as to adjust the average value of the output voltage of the energy storage output module to be continuous before and after the zero-crossing point of the first voltage. The starting point for the interpolation compensation is the zero-crossing point of the first voltage.

11. The output voltage compensation method for a dual active bridge converter according to claim 10, characterized in that, After controlling the second lower bridge arm transistor to turn on and maintaining the insertion time, the process includes: The second lower bridge arm transistor is turned off, and the second upper bridge arm transistor is turned on.

12. The output voltage compensation method for a dual active bridge converter according to claim 1, characterized in that, The secondary bridge arm circuit includes: a first upper bridge arm transistor (S1H), a second upper bridge arm transistor (S1L), a first lower bridge arm transistor (S2L), a second lower bridge arm transistor (S2H), a first bus capacitor (C1), and a second bus capacitor (C2); the first upper bridge arm transistor and the second upper bridge arm transistor are connected between the first terminal of the energy storage output module and the first terminal of the secondary coil of the transformer module; the first lower bridge arm transistor and the second lower bridge arm transistor are connected between the second terminal of the second upper bridge arm transistor and the second terminal of the energy storage output module; the first bus capacitor is connected between the first terminal of the first upper bridge arm transistor and the second terminal of the integrating module; and the second bus capacitor is connected between the second terminal of the first bus capacitor and the second terminal of the second lower bridge arm transistor. The step of controlling the conduction state of the secondary bridge arm circuit at the insertion compensation starting point by an insertion time (Δt) to adjust the average value of the output voltage of the energy storage output module to be continuous before and after the zero-crossing point of the first voltage includes: The first upper bridge arm transistor and the first lower bridge arm transistor are kept in the on state. When the phase of the first current leads the phase of the first voltage, or is equal to the phase of the first voltage, at the starting point of the insertion compensation, the second lower bridge arm transistor is controlled to turn off and remain off for a duration equal to the insertion time, and the second upper bridge arm transistor is controlled to turn on and remain on for a duration equal to the insertion time, so as to adjust the average value of the output voltage of the energy storage output module to be continuous before and after the zero-crossing point of the first voltage, and adjust the average value of the first current to be continuous before and after the zero-crossing point of the first voltage. The insertion compensation starting point is the compensation period of the second voltage corresponding to the zero-crossing point of the first voltage, and the time before the end of the compensation period is a first preset time interval.

13. An output voltage compensation device for a dual active bridge converter, characterized in that, include: The parameter acquisition module obtains the first voltage (Vg) and first current (ig) of the grid-side power supply, and the second voltage (Vg) of the integration module. ) and capacitance value (Cr); The starting point determination module is used to determine the start point of the plug-in compensation of the output voltage of the energy storage output module based on the zero-crossing time of the first voltage; the start point of the plug-in compensation is the target time after the zero-crossing time of the first voltage. The compensation calculation module is used to calculate the second voltage (based on the first voltage and first current of the grid-side power supply) of the integration module. The voltage compensation amount (ΔVb) of the integral module at the end point of the insertion compensation is determined by the voltage (Cr) of the capacitor value and the switching cycle of the switching module of the secondary bridge arm circuit. The time calculation module is used to determine the insertion time (Δt) based on the voltage compensation amount (ΔVb) of the integral module at the end point of the insertion compensation. The bridge arm control module is used to control the conduction state of the secondary bridge arm circuit at the insertion compensation starting point by an insertion time (Δt) to adjust the average value of the output voltage of the energy storage output module to be continuous before and after the zero-crossing point of the first voltage; it is also used to execute the output voltage compensation method of the dual active bridge converter according to any one of claims 1-12.

14. A dual active bridge converter component, characterized in that, Includes: a dual active bridge converter and an output voltage compensation device for the dual active bridge converter as described in claim 13.

Images