Discrete single phase-shift control method for dual active bridge dc-dc converter based on disturbance compensation

Abstract

The application discloses a discrete single-phase-shift control method for a dual active bridge DC-DC converter based on disturbance compensation. First, the input voltage, output voltage and output current of the dual active bridge DC-DC converter are sampled, and the open-loop phase-shift ratio of the dual active bridge DC-DC converter is calculated according to the output voltage reference value. Then, it is judged which level of the n-level output voltage interval the output voltage belongs to, and the corresponding compensation phase-shift ratio is selected to compensate the open-loop phase-shift ratio to obtain the actual phase-shift ratio. Finally, the corresponding control pulse group is generated according to the actual phase-shift ratio and acts on the dual active bridge DC-DC converter, so as to realize the adjustment of the output voltage of the dual active bridge DC-DC converter. The control method can make the dual active bridge DC-DC converter have a faster dynamic response speed and better stability when input voltage mutation and load mutation occur, so that the system has better dynamic performance and steady-state performance.

Description

Technical Field

[0001] This invention relates to the field of power electronics technology, and in particular to a discrete single-phase shift control method for a dual active bridge DC-DC converter based on disturbance compensation. Background Technology

[0002] Dual active bridge (DAB) DC-DC converters are widely used in electric vehicles, distributed power sources, and DC distribution networks due to their advantages such as high power density, bidirectional energy flow, ease of soft switching, and electrical isolation. Currently, the main control method for DAB DC-DC converters is phase-shift control, including single-phase-shift (SPS) control, dual-phase-shift (DPS) control, extended-phase-shift (EPS) control, and triple-phase-shift (TPS) control. Among these, SPS control has only one degree of freedom in the outer phase shift, making it simple and easy to implement.

[0003] In the aforementioned engineering applications, dual active bridge DC-DC converters often operate as controllable voltage sources. Their slow dynamic response prolongs the impact time of disturbances, thus affecting system performance and stability. Therefore, researching the fast and robust dynamic performance of dual active bridge DC-DC converters is crucial. Currently, control methods to improve the dynamic response speed of dual active bridge DC-DC converters mainly include the load current feedforward method and the PI compensation network design method. While both methods can effectively improve the dynamic response speed of dual active bridge DC-DC converters to some extent, their control parameter design is relatively complex. Therefore, researching a control method that can simultaneously improve the steady-state and transient performance of dual active bridge DC-DC converters while simplifying control parameter design is essential. Summary of the Invention

[0004] To improve the dynamic response speed of a dual active bridge DC-DC converter, this invention proposes a discrete single-phase shift control method based on disturbance compensation. The method samples the input voltage, output voltage, and output current of the dual active bridge DC-DC converter, calculates the open-loop phase shift ratio based on the output voltage reference value, determines which stage of the n-stage output voltage range the output voltage belongs to, selects the corresponding compensation phase shift ratio to compensate the open-loop phase shift ratio, and finally generates a corresponding control pulse group based on the actual phase shift ratio to act on the dual active bridge DC-DC converter, thereby regulating the output voltage of the dual active bridge DC-DC converter. This control system eliminates the need for a PI controller, simplifying the parameter design of the control system and enhancing its stability; the use of multi-stage discrete control accelerates the dynamic response speed of the system.

[0005] The technical solution of the discrete single-phase shift control method for a dual active bridge DC-DC converter based on disturbance compensation proposed in this invention is as follows:

[0006] A discrete single-phase-shift control method for a dual active bridge DC-DC converter based on disturbance compensation is disclosed. The dual active bridge DC-DC converter includes a transformer and a primary H-bridge and a secondary H-bridge connected to the primary and secondary sides of the transformer, respectively. The primary and secondary H-bridges are full-bridge structures comprising a total of 8 switching transistors. The control method for the dual active bridge DC-DC converter is used to control the 8 switching transistors and includes the following steps:

[0007] Step 1: Set the sampling period T of the DAB DC-DC converter s The output voltage value U of the dual active bridge DC-DC converter is sampled at the beginning of each switching cycle. o Input voltage value U in With output current value i o ;

[0008] Step 2: Set n sets of compensation shift ratios ΔD i , i∈[1,n];

[0009] Step 3: Calculate the open-loop shift ratio D of the dual active bridge DC-DC converter based on the output voltage reference value. ol ;

[0010] Step 4: Determine the output voltage U obtained from sampling in Step 1. o Which level in the nth output voltage range does it belong to? If the output voltage U sampled in step one... o If it belongs to level i, then select the corresponding compensation shift ratio ΔD. i Used to compensate for the open-loop shift compared to D calculated in step three.ol Thus, the actual shift ratio of the dual active bridge DC-DC converter to D is obtained. i =D ol +ΔD i ;

[0011] Step 5: Based on the actual displacement ratio D obtained in Step 4. i Generate the corresponding control pulse group P i The action is applied to the eight switching transistors of the dual active bridge DC-DC converter.

[0012] Furthermore, step two specifically includes:

[0013] 2.1. Perform initialization and set the output voltage reference value U of the dual active bridge DC-DC converter. ref and output voltage error reference value e ref ,j,

[0014] 2.2 Divide the output voltage of the dual active bridge DC-DC converter into n intervals, where the first-stage output voltage interval satisfies U o ≤U ref –e ref,1 The corresponding compensation shift ratio is ΔD1; ...; the x-th stage output voltage range satisfies U ref –e ref,x-1 o ≤U ref –e ref,x The corresponding compensation shift ratio is ΔD x , ...; No. The stage output voltage range meets Its corresponding compensation shift ratio is No. The stage output voltage range meets Its corresponding compensation shift ratio is ...; the output voltage range of the y-th stage satisfies U ref +e ref,n-y+1 o ≤U ref +e ref,n-y The corresponding compensation shift ratio is ΔD y , [n–1];……;The nth stage output voltage range satisfies U ref +e ref,1 o The corresponding compensation shift ratio is ΔD n ;

[0015] ​​​2.3. Set the compensation shift ratio corresponding to the n-stage output voltage range to satisfy: And satisfy ΔD m =–ΔD n–m+1 ,

[0016] Furthermore, step three specifically includes:

[0017] 3.1 Set the switching frequency f of the dual active bridge DC-DC converter. s ;

[0018] 3.2 The open-loop shift ratio of the dual active bridge DC-DC converter is D ol The following relationship must be satisfied:

[0019]

[0020] In the formula L s U is the auxiliary inductance value of the dual active bridge DC-DC converter; ref i is the reference value for the output voltage of the dual active bridge DC-DC converter; o f is the output current value of the dual active bridge DC-DC converter; s U is the switching frequency of the dual active bridge DC-DC converter; n is the transformer turns ratio of the dual active bridge DC-DC converter; U o U is the output voltage value of the dual active bridge DC-DC converter; in The input voltage value is the value of the dual active bridge DC-DC converter.

[0021] Furthermore, step five specifically includes:

[0022] 5.1 Select one switch from the switches of the primary H-bridge of the dual active bridge DC-DC converter as a standard switch and generate its control pulse. The control pulse of the standard switch is a square wave signal with a duty cycle of 50%.

[0023] 5.2. The control pulse of the standard switching transistor is compared with the actual shift ratio D obtained in step four. i Phase shifting is performed to obtain the control pulses for the remaining 7 switching transistors. Then, the control pulse of the standard switching transistor is combined with the control pulses of the remaining 7 switching transistors to form the control pulse group P for this switching cycle. i .

[0024] This invention proposes a discrete single-phase shift control method for a dual active bridge DC-DC converter based on disturbance compensation. By sampling the output voltage, input voltage, and output current values ​​of the dual active bridge DC-DC converter, the open-loop phase shift ratio is calculated. Different compensation phase shift ratios are set for different output voltage ranges. The open-loop phase shift ratio is compensated by selecting the compensation phase shift ratio. Finally, the controller generates a corresponding control pulse group to adjust the output voltage of the dual active bridge DC-DC converter.

[0025] The beneficial effects of this invention are:

[0026] (1) This invention proposes a discrete single-phase shift control method for a dual active bridge DC-DC converter based on disturbance compensation. The input voltage and output current values ​​of the dual active bridge DC-DC converter are introduced into the control, so that the system has a faster dynamic response speed when input voltage and load change occur.

[0027] (2) The present invention sets up a multi-level compensation shift ratio, so that when the system faces different degrees of sudden change, a suitable compensation shift ratio can be selected, thereby improving the stability of the system.

[0028] (3) Compared with the traditional dual active bridge DC-DC converter control system, the present invention uses a disturbance compensation-based discrete single phase shift control method for dual active bridge DC-DC converters, which does not require the use of a PI controller, making the parameter design of the control method simpler. Attached Figure Description

[0029] Figure 1 This is a block diagram of a discrete single-phase-shift control method for a dual active bridge DC-DC converter based on disturbance compensation proposed in this invention.

[0030] Figure 2 This is a schematic diagram of the circuit structure in a specific embodiment of the discrete single-phase shift control method for a dual active bridge DC-DC converter based on disturbance compensation proposed in this invention.

[0031] Figure 3 This is a control principle diagram of a specific embodiment of the discrete single-phase shift control method for a dual active bridge DC-DC converter based on disturbance compensation proposed in this invention;

[0032] Figure 4 This is a time-domain simulation waveform of the dual active bridge DC-DC converter under steady-state conditions during a certain period when the proposed disturbance-compensated discrete single-phase-shift control method for the dual active bridge DC-DC converter is applied to the embodiment.

[0033] Figure 5(a) and (b) are time-domain simulation waveforms of the dual active bridge DC-DC converter according to an embodiment of the present invention under load change and input voltage change, respectively.

[0034] Figure 6 In the figure, (a) and (b) are time-domain simulation waveforms of the voltage closed-loop controlled dual active bridge DC-DC converter under load change and input voltage change, respectively. Detailed Implementation

[0035] To make the technical solution of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. Specific details in the following embodiments, such as the specific circuit structures and parameters of these circuit elements, are provided to enable a better understanding of the embodiments of the present invention. Even in the absence of some details or the use of other methods, components, materials, etc., the embodiments of the present invention can still be implemented and understood.

[0036] like Figure 1 As shown, a discrete single-phase-shift control method for a dual active bridge DC-DC converter based on disturbance compensation is disclosed. The dual active bridge DC-DC converter includes a transformer and a primary H-bridge and a secondary H-bridge connected to the primary and secondary sides of the transformer, respectively. The primary and secondary H-bridges are full-bridge structures comprising a total of 8 switching transistors. The control method for the dual active bridge DC-DC converter is used to control the 8 switching transistors and includes the following steps:

[0037] Step 1: Set the sampling period T of the DAB DC-DC converter s The output voltage value U of the dual active bridge DC-DC converter is sampled at the beginning of each switching cycle. o Input voltage value U in With output current value i o ;

[0038] Step 2: Set n sets of compensation shift ratios ΔD i , i∈[1,n]. The specific method is as follows:

[0039] 2.1. Perform initialization and set the output voltage reference value U of the dual active bridge DC-DC converter. ref and output voltage error reference value e ref,j ,

[0040] 2.2 Divide the output voltage of the dual active bridge DC-DC converter into n intervals, where the first-stage output voltage interval satisfies U o ≤U ref –e ref,1 The corresponding compensation shift ratio is ΔD1; ...; the x-th stage output voltage range satisfies U ref–e ref,x-1 o ≤U ref –e ref,x The corresponding compensation shift ratio is ΔD x , ...; No. The stage output voltage range meets Its corresponding compensation shift ratio is No. The stage output voltage range meets Its corresponding compensation shift ratio is ...; the output voltage range of the y-th stage satisfies U ref +e ref,n-y+1 o ≤U ref +e ref,n-y The corresponding compensation shift ratio is ΔD y , [n–1];……;The nth stage output voltage range satisfies U ref +e ref,1 o The corresponding compensation shift ratio is ΔD n .

[0041] 2.3. Set the compensation shift ratio corresponding to the n-stage output voltage range to satisfy: And satisfy ΔD m =–ΔD n–m+1 ,

[0042] Step 3: Calculate the open-loop shift ratio D of the dual active bridge DC-DC converter based on the output voltage reference value. ol The specific method is as follows:

[0043] 3.1 Set the switching frequency f of the dual active bridge DC-DC converter. s .

[0044] 3.2 The open-loop shift ratio of the dual active bridge DC-DC converter is D ol The following relationship must be satisfied:

[0045]

[0046] In the formula L s U is the auxiliary inductance value of the dual active bridge DC-DC converter; ref i is the reference value for the output voltage of the dual active bridge DC-DC converter; o f is the output current value of the dual active bridge DC-DC converter; s ​​​U is the switching frequency of the dual active bridge DC-DC converter; n is the transformer turns ratio of the dual active bridge DC-DC converter; U o U is the output voltage value of the dual active bridge DC-DC converter; in The input voltage value is the value of the dual active bridge DC-DC converter.

[0047] Step 4: Determine the output voltage U obtained from sampling in Step 1. o Which level in the n-level output voltage range does it belong to? If the output voltage U sampled in step one... o If it belongs to level i, then select the corresponding compensation shift ratio ΔD. i Used to compensate for the open-loop shift compared to D calculated in step three. ol Thus, the actual shift ratio of the dual active bridge DC-DC converter to D is obtained. i =D ol +ΔD i .

[0048] Step 5: Based on the actual displacement ratio D obtained in Step 4. i Generate the corresponding control pulse group P i This applies to the eight switching transistors of the dual active bridge DC-DC converter. The specific method is as follows:

[0049] 5.1 Select one switch from the switches of the primary H-bridge of the dual active bridge DC-DC converter as a standard switch and generate its control pulse. The control pulse of the standard switch is a square wave signal with a duty cycle of 50%.

[0050] 5.2. The control pulse of the standard switching transistor is compared with the actual shift ratio D obtained in step four. i Phase shifting is performed to obtain the control pulses for the remaining 7 switching transistors. Then, the control pulse of the standard switching transistor is combined with the control pulses of the remaining 7 switching transistors to form the control pulse group P for this switching cycle. i .

[0051] The proposed invention provides a discrete single-phase-shift control method for dual active bridge DC-DC converters based on disturbance compensation. This method is applicable to dual active bridge DC-DC converters, which consist of a transformer and primary and secondary H-bridges connected to both sides of the transformer. Both the primary and secondary H-bridges are full-bridge structures with a total of eight switching transistors in the two bridge arms. Figure 2 The diagram shows a two-level topology of a dual active bridge DC-DC converter.

[0052] This invention proposes a discrete single-phase shift control method for a dual active bridge DC-DC converter based on disturbance compensation. Firstly, the input voltage U of the dual active bridge DC-DC converter is...in Output voltage U o and output current i o Sampling is performed, and the output voltage reference value U is used as a reference. ref Calculate the open-loop shift ratio D of the dual active bridge DC-DC converter. ol Then determine the output voltage U o Which level in the 6-level output voltage range does it belong to, and select the corresponding compensation shift ratio ΔD? i Used to compensate for open-loop shift compared to D ol The actual displacement was obtained compared to D. i Finally, based on the actual movement compared to D i Generate the corresponding control pulse group P i The eight switching transistors of the dual active bridge DC-DC converter are used to regulate the output voltage of the dual active bridge DC-DC converter.

[0053] Taking n=6 as an example, the technical solution adopted in this invention is:

[0054] A discrete single-phase-shift control method for a dual active bridge DC-DC converter based on disturbance compensation includes the following steps:

[0055] Step 1: Set the sampling period T of the DAB DC-DC converter s The output voltage value U of the dual active bridge DC-DC converter is sampled at the beginning of each switching cycle. o Input voltage value U in With output current value i o ;

[0056] Step 2: Set up 6 sets of compensation shift ratios ΔD i , i∈[1,6], the specific method is as follows:

[0057] 2.1. Perform initialization and set the output voltage reference value U of the dual active bridge DC-DC converter. ref and output voltage error reference value e ref,1 =0.1V, e ref,2 =0.05V.

[0058] 2.2, such as Figure 3 As shown, the output voltage of the dual active bridge DC-DC converter is divided into 6 intervals. The first stage output voltage interval satisfies U o ≤U ref –e ref,1 The corresponding compensation shift ratio is ΔD1; the second-stage output voltage range satisfies U ref –e ref,1 o ≤U ref –e​ref,2 The corresponding compensation shift ratio is ΔD2; the third-stage output voltage range satisfies U ref –e ref,2 o ≤U ref Its corresponding compensation shift ratio is ΔD3; the fourth stage output voltage range satisfies U ref o ≤U ref +e ref,2 Its corresponding compensation shift ratio is ΔD4; the output voltage range of the 5th stage satisfies U ref +e ref,2 o ≤U ref +e ref,1 Its corresponding compensation shift ratio is ΔD5; the output voltage range of the 6th stage satisfies U ref +e ref,1 o The corresponding compensation shift ratio is ΔD6.

[0059] 2.3 The compensation shift ratio corresponding to the 6-level output voltage range shall satisfy: -0.5<ΔD6<ΔD5<ΔD4<0<ΔD3<ΔD2<ΔD1<0.5; and satisfy ΔD1=–ΔD6=0.2, ΔD2=–ΔD5=0.1, ΔD3=–ΔD4=0.05.

[0060] Step 3: Calculate the open-loop shift ratio D ol The specific method is as follows:

[0061] 3.1 Set the switching period f of the dual active bridge DC-DC converter. s .

[0062] 3.2 The open-loop shift ratio of the dual active bridge DC-DC converter is D ol The following relationship must be satisfied:

[0063]

[0064] In the formula L s U is the auxiliary inductance value of the dual active bridge DC-DC converter; ref i is the reference value for the output voltage of the dual active bridge DC-DC converter; o f is the output current value of the dual active bridge DC-DC converter; s U is the switching frequency of the dual active bridge DC-DC converter, which is 50kHz in this embodiment; n is the transformer turns ratio of the dual active bridge DC-DC converter; U o U is the output voltage value of the dual active bridge DC-DC converter; in ​​​​The input voltage value is the value of the dual active bridge DC-DC converter.

[0065] Step 4: Determine the output voltage U obtained from sampling in Step 1. o Which level in the 6-level output voltage range does it belong to? If the output voltage U sampled in step one... o If it belongs to level i, then select the corresponding compensation shift ratio ΔD. i Used to compensate for the open-loop shift compared to D calculated in step three. ol Thus, the actual shift ratio of the dual active bridge DC-DC converter to D is obtained. i =D ol +ΔD i .

[0066] Step 5: Based on the actual displacement ratio D obtained in Step 4. i Generate the corresponding control pulse group P i This is applied to the eight switching transistors S1-S8 of the dual active bridge DC-DC converter. The specific method is as follows:

[0067] 5.1 Select switch S1 on the first arm of the primary H-bridge as the standard switch, and generate the control pulse v for switch S1. p1 The control pulse v p1 It is a square wave signal with a duty cycle of 50%.

[0068] 5.2. The control pulse v of the switching transistor S1 p1 Based on the actual displacement ratio D obtained in step four. i Phase shifting is performed to obtain the control pulses v for the remaining 7 switching transistors. p2 ~v p8 Then the control pulse v of S1 p1 The control pulses v of the remaining 7 switching transistors p2 ~v p8 The control pulse group P that constitutes this switching cycle i .

[0069] The method of this embodiment was simulated and analyzed in the time domain using Matlab / Simulink software. The results are as follows:

[0070] Figure 4 , Figure 5 , Figure 6 The simulation conditions are as follows: Output voltage reference value U ref The voltage is 48V, the transformer turns ratio n is 1, and the auxiliary inductor L... s 40μH, switching frequency f s The frequency is 50kHz, and both the input capacitor C1 and the output capacitor C2 are 470μF.

[0071] Figure 4 The waveform in the time domain of the dual active bridge DC-DC converter during a certain steady-state time period is shown in the embodiment when the control method of the present invention is used. Figure 4 The horizontal axis represents time (s), and the vertical axes represent the control pulse v. p4 (V), Output voltage U o (V) and inductor current i L (A). From Figure 4 As can be seen from the above, the discrete single-phase shift control method for a dual active bridge DC-DC converter based on disturbance compensation proposed in this invention can regulate the output voltage of the dual active bridge DC-DC converter. In steady state, the controller mainly selects compensation shift ratios ΔD3 and ΔD4 to compensate the open-loop shift ratio. When the output voltage is in the third-level output voltage range, the controller selects compensation shift ratio ΔD3 to compensate the open-loop shift ratio, generating control pulse group P3 to increase the output voltage; when the output voltage is in the fourth-level output voltage range, the controller selects compensation shift ratio ΔD4 to compensate the open-loop shift ratio, generating control pulse group P4 to decrease the output voltage.

[0072] Figure 5 (a) is the time-domain simulation waveform of the dual active bridge DC-DC converter under sudden load changes when the control method of the present invention is used in the embodiment. Figure 5 (b) is the time-domain simulation waveform of the dual active bridge DC-DC converter when the control method of the present invention is used in the embodiment, under the condition of sudden change in input voltage. Figure 6 (a) is the time-domain simulation waveform of the dual active bridge DC-DC converter under sudden load changes when voltage closed-loop control is used in the embodiment. Figure 6 (b) is the time-domain simulation waveform of the dual active bridge DC-DC converter when the input voltage changes suddenly, using voltage closed-loop control in the embodiment. Figure 5 and Figure 6 The x-axis represents time (s). Figure 5 (a) and Figure 6 (a) The ordinates of the graph are the output voltage U. o (V), Output current i o (A) and inductor current i L (A), Figure 5 (b) and Figure 6 (b) The ordinates are the output voltage U o (V), Input voltage U in (V) and inductor current i L (A)

[0073] Figure 5 (a) and Figure 6In (a), the load changes from 11Ω to 22Ω at 0.2s. The transient response time of the traditional voltage closed-loop control is 0.03s. The dual active DC-DC converter of the present invention has almost no transient response time, and the system directly enters steady state after the load change. Figure 5 (b) and Figure 6 (b) The input voltage changes from 96V to 86V at 0.2s. The transient response time of the traditional voltage closed-loop control is 0.028s. The dual active DC-DC converter of the present invention has almost no transient response time. The system directly enters steady state after the sudden change in input voltage.

[0074] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A discrete single-phase-shift control method for a dual active bridge DC-DC converter based on disturbance compensation, wherein the dual active bridge DC-DC converter includes a transformer, and a primary H-bridge and a secondary H-bridge connected to the primary and secondary sides of the transformer respectively, wherein the primary H-bridge and the secondary H-bridge are full-bridge structures comprising a total of 8 switching transistors, characterized in that, The control method for the dual active bridge DC-DC converter is used to control the eight switching transistors, and includes the following steps: Step 1: Set the sampling period T of the DAB DC-DC converter s The output voltage value U of the dual active bridge DC-DC converter is sampled at the beginning of each switching cycle. o Input voltage value U in With output current value i o ; Step 2: Set n sets of compensation shift ratios ΔD i , i∈[1,n]; Step 3: Calculate the open-loop shift ratio D of the dual active bridge DC-DC converter based on the output voltage reference value. ol ; Step 4: Determine the output voltage U obtained from sampling in Step 1. o Which level in the n-level output voltage range does it belong to? If the output voltage U sampled in step one... o If it belongs to level i, then select the corresponding compensation shift ratio ΔD. i Used to compensate for the open-loop shift compared to D calculated in step three. ol Thus, the actual shift ratio of the dual active bridge DC-DC converter to D is obtained. i =D ol +ΔD i ; Step 5: Based on the actual displacement ratio D obtained in Step 4. i Generate the corresponding control pulse group P i The action is applied to the eight switching transistors of the dual active bridge DC-DC converter.

2. The discrete single-phase-shift control method for a dual active bridge DC-DC converter based on disturbance compensation as described in claim 1, characterized in that, Step two specifically includes: 2.

1. Perform initialization and set the output voltage reference value U of the dual active bridge DC-DC converter. ref and output voltage error reference value e ref,j , 2.2 Divide the output voltage of the dual active bridge DC-DC converter into n intervals, where the first-stage output voltage interval satisfies U o ≤U ref –e ref,1 The corresponding compensation shift ratio is ΔD1; ...; the x-th stage output voltage range satisfies U ref –e ref,x-1 o ≤U ref –e ref,x The corresponding compensation shift ratio is ΔD x , No. The stage output voltage range meets Its corresponding compensation shift ratio is No. The output voltage range of the stage satisfies U ref o ≤ Its corresponding compensation shift ratio is ...; the output voltage range of the y-th stage satisfies U ref +e ref,n-y+1 o ≤U ref +e ref,n-y The corresponding compensation shift ratio is ΔD y , ...; the nth stage output voltage range satisfies U ref +e ref,1 o The corresponding compensation shift ratio is ΔD n ;​​​​ 2.

3. Set the compensation shift ratio corresponding to the n-stage output voltage range to satisfy: <ΔD1<0.5; and satisfy ΔD m =–ΔD n–m+1 , 3. The discrete single-phase-shift control method for a dual active bridge DC-DC converter based on disturbance compensation as described in claim 1, characterized in that, Step three specifically includes: 3.1 Set the switching frequency f of the dual active bridge DC-DC converter. s ; 3.2 The open-loop shift ratio of the dual active bridge DC-DC converter is D ol The following relationship must be satisfied: In the formula L s U is the auxiliary inductance value of the dual active bridge DC-DC converter; ref i is the reference value for the output voltage of the dual active bridge DC-DC converter; o f is the output current value of the dual active bridge DC-DC converter; s U is the switching frequency of the dual active bridge DC-DC converter; n is the transformer turns ratio of the dual active bridge DC-DC converter; U o U is the output voltage value of the dual active bridge DC-DC converter; in The input voltage value is the value of the dual active bridge DC-DC converter.

4. The discrete single-phase-shift control method for a dual active bridge DC-DC converter based on disturbance compensation as described in claim 1, characterized in that, Step five specifically includes: 5.1 Select one switch from the switches of the primary H-bridge of the dual active bridge DC-DC converter as a standard switch and generate its control pulse. The control pulse of the standard switch is a square wave signal with a duty cycle of 50%. 5.

2. The control pulse of the standard switching transistor is compared with the actual shift ratio D obtained in step four. i Phase shifting is performed to obtain the control pulses for the remaining 7 switching transistors. Then, the control pulse of the standard switching transistor is combined with the control pulses of the remaining 7 switching transistors to form the control pulse group P for this switching cycle. i .

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