A bidirectional isolated dc-dc converter voltage compensation control method and device

Abstract

The application provides a bidirectional isolation type DC converter voltage compensation control method and device, active power transmitted by a DC / AC converter and an AC / DC converter in a bidirectional isolation type DC converter is acquired; a phase shift control angle difference of the bidirectional isolation type DC converter is calculated based on the active power; the DC / AC converter and the AC / DC converter are controlled based on the phase shift control angle difference, voltage mismatch compensation control of the bidirectional isolation type DC converter is realized based on the phase shift control angle difference of the bidirectional isolation type DC converter, the overall operation efficiency of the bidirectional isolation type DC converter is improved, and the operation performance is improved; the technical scheme provided by the application obtains a phase of the bidirectional isolation type DC converter under phase shift control through a phase analysis method, and then determines voltage matching conditions on both sides of the converter through the phase of the bidirectional isolation type DC converter, and voltage matching control of the bidirectional isolation type DC converter is realized by introducing internal phase shift.

Description

Technical Field

[0001] This invention relates to the field of DC-DC conversion technology, and specifically to a voltage compensation control method and apparatus for a bidirectional isolated DC-DC converter. Background Technology

[0002] Considering key issues such as multiple AC / DC voltage conversion matching, bidirectional active power control, and electrical isolation and grounding protection between different voltage levels, seamless hybrid AC / DC multi-voltage-level distribution systems represent a new direction for power distribution development towards the future energy internet. As the DC conversion link in hybrid distribution systems, bidirectional isolated DC converters, which offer advantages such as high power density, high efficiency, simple structure, and soft switching, are commonly used. These bidirectional isolated DC converters achieve isolation, conversion, and power control between multiple DC voltage levels in the hybrid distribution system.

[0003] A bidirectional isolated DC-DC converter connects its output to a distributed power source (battery, capacitor, active load, etc.) and its input to a DC bus. The turns ratio of its internal high-frequency transformer is the ratio of the input DC voltage to the output DC voltage. Ideally, the input and output DC voltages of the bidirectional isolated DC-DC converter are constant and matched, meaning the high-frequency transformer turns ratio is 1. However, in actual operation, the output DC voltage fluctuates with changes in operating conditions, and the input DC voltage also fluctuates due to increases or decreases in the load on the connected bus. When this occurs, the voltages on both sides of the bidirectional isolated DC-DC converter deviate from their original standard values, and the high-frequency transformer turns ratio is no longer 1, resulting in voltage mismatch. Voltage mismatch in bidirectional isolated DC-DC converters can easily lead to characteristic loss, mainly manifested as:

[0004] 1) The change in the waveform coefficient of the medium and high frequency AC link current in the bidirectional isolated DC-DC converter directly reflects the change in the AC link current harmonics, the increase in current stress, and the resulting changes in the losses of the switching transistors and high frequency transformers.

[0005] 2) The original soft-switching conditions of the bidirectional isolated DC-DC converter have changed, causing the soft-switching characteristics of the bidirectional isolated DC-DC converter to be lost and replaced with hard switching. This increases switching losses and reduces the overall efficiency of the bidirectional isolated DC-DC converter.

[0006] To address the issue that voltage mismatch in bidirectional isolated DC-DC converters can easily lead to characteristic loss, existing technologies generally use return power as the objective function for optimization control. However, return power cannot be completely equivalent to the equivalent mathematical model of soft switching, resulting in inaccurate modeling and control results. Furthermore, modeling with return power is overly complex, involving excessive mathematical calculations, and cannot directly and intuitively represent the soft-switching compensation control principle. Consequently, the overall operating efficiency and performance of the bidirectional isolated DC-DC converter are low. Summary of the Invention

[0007] To overcome the shortcomings of low operating efficiency and poor operating performance in the prior art, this invention provides a voltage compensation control method for a bidirectional isolated DC-DC converter, comprising:

[0008] Obtain the active power transmitted by the DC / AC converter and the AC / DC converter in a bidirectional isolated DC-DC converter.

[0009] When the voltages on both sides of the bidirectional isolated DC-DC converter are mismatched, the phase shift control angle difference of the bidirectional isolated DC-DC converter is calculated based on the active power.

[0010] Voltage compensation is performed on the DC / AC converter and AC / DC converter based on the phase shift control angle difference.

[0011] The calculation of the phase shift control angle difference of the bidirectional isolated DC-DC converter based on the active power includes:

[0012] The relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase-shift control angle difference of the bidirectional isolated DC converter is determined based on the relationship between the AC side voltage harmonic components of the DC / AC converter and the AC current harmonic components of the bidirectional isolated DC converter and the phase-shift control angle difference of the bidirectional isolated DC converter.

[0013] Based on the obtained DC-side voltage of the DC / AC converter, DC-side voltage of the AC / DC converter, turns ratio of the high-frequency transformer, and the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase-shift control angle difference of the bidirectional isolated DC-DC converter, the phase-shift control angle difference between the second bridge arm and the first bridge arm of the DC / AC converter, the phase-shift control angle difference between the third bridge arm and the first bridge arm of the AC / DC converter, and the phase-shift control angle difference between the fourth bridge arm and the first bridge arm of the AC / DC converter are calculated.

[0014] The calculation of the phase-shift control angle differences between the second and first arms of the DC / AC converter, the third and first arms of the AC / DC converter, and the fourth and first arms of the AC / DC converter based on the obtained DC-side voltage of the DC / AC converter, the DC-side voltage of the AC / DC converter, the turns ratio of the high-frequency transformer, and the relationship between the active power transmitted by the DC / AC converter and the phase-shift control angle difference of the bidirectional isolated DC-AC converter includes:

[0015] When V in / mV out When the value is greater than 1, the phase shift control angle difference between the second bridge arm and the first bridge arm is calculated based on the DC-side voltage of the DC / AC converter, the DC-side voltage of the AC / DC converter, and the turns ratio of the high-frequency transformer. The phase shift control angle difference between the third bridge arm and the first bridge arm and the phase shift control angle difference between the fourth bridge arm and the first bridge arm are calculated based on the DC-side voltage of the DC / AC converter, the turns ratio of the high-frequency transformer, and the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC-DC converter.

[0016] When V in / mV out When <1, the phase shift control angle difference between the second bridge arm and the first bridge arm in the DC / AC converter is determined to be 0. Based on the DC side voltage of the DC / AC converter, the turns ratio of the high-frequency transformer, and the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC converter, the phase shift control angle difference between the third bridge arm and the first bridge arm and the phase shift control angle difference between the fourth bridge arm and the first bridge arm are calculated.

[0017] Among them, V in V is the DC-side voltage of the DC / AC converter. out denoted as AC side voltage of the AC / DC converter, and m is the turns ratio of the high-frequency transformer in the bidirectional isolated DC converter.

[0018] When V in / mVo ut When the difference is greater than 1, the phase shift control angle difference between the second bridge arm and the first bridge arm is determined by the following formula:

[0019]

[0020] In the formula, α1 is the phase shift control angle difference between the second bridge arm and the first bridge arm in the DC / AC converter, and V in V is the DC-side voltage of the DC / AC converter. outThis is the DC-side voltage of the AC / DC converter.

[0021] The calculation of the phase shift control angle difference between the third arm and the first arm, and the phase shift control angle difference between the fourth arm and the first arm, based on the DC-side voltage of the DC / AC converter, the turns ratio of the high-frequency transformer, and the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC-DC converter, includes:

[0022] When V in / mV out When >1, α2 = α3 is satisfied, and And by substituting α2=α3 into the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC converter, the phase shift control angle difference between the third bridge arm and the first bridge arm and the phase shift control angle difference between the fourth bridge arm and the first bridge arm are obtained.

[0023] When V in / mV out When <1, α2=α3-2arccos(V) is satisfied. out_ref / V out ), set α1=0 and α2=α3-2arccos(V out_ref / V out Substituting the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC converter, we obtain the phase shift control angle difference between the third bridge arm and the first bridge arm and the phase shift control angle difference between the fourth bridge arm and the first bridge arm.

[0024] Where α2 is the phase shift control angle difference between the third bridge arm and the first bridge arm, α3 is the phase shift control angle difference between the fourth bridge arm and the first bridge arm, and V out_ref This is the reference value for the DC-side voltage of the AC / DC converter.

[0025] The relationship between the AC side voltage harmonic components of the DC / AC converter and the AC / DC converter, the AC current harmonic components of the bidirectional isolated DC converter, and the phase shift control angle difference of the bidirectional isolated DC converter is determined by the following formula:

[0026]

[0027] In the formula, The AC voltage of the DC / AC converter has a 2n+1th harmonic component. The AC voltage of the AC / DC converter has a 2n+1th harmonic component. The AC current of the bidirectional isolated DC-DC converter is the 2n+1th harmonic component, C is the equivalent capacitance of the high-frequency transformer, and L is the 2n+1st harmonic component.S ω is the leakage inductance of the high-frequency transformer, ω is the angular velocity of the switching frequency, and j is a complex unit.

[0028] The relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC converter is determined by the following formula:

[0029]

[0030] In the formula, P ab(2n+1) P is the active power of the DC / AC converter under the 2n+1th harmonic. cd(2n+1) X represents the active power of the AC / DC converter under the 2n+1th harmonic. s(2n+1) X is an intermediate quantity, and X s(2n+1) =(2n+1)ωL s -(1 / (2n+1)ωC).

[0031] On the other hand, the present invention also provides a bidirectional isolated DC-DC converter voltage compensation control device, comprising:

[0032] The acquisition module is used to acquire the active power transmitted by the DC / AC converter and the AC / DC converter in the bidirectional isolated DC-DC converter.

[0033] The calculation module is used to calculate the phase shift control angle difference of the bidirectional isolated DC-DC converter based on the active power when the voltages on both sides of the bidirectional isolated DC-DC converter are mismatched.

[0034] The control module is used to perform voltage compensation on the DC / AC converter and the AC / DC converter based on the phase shift control angle difference.

[0035] The computing module includes:

[0036] The determining unit is used to determine the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase-shift control angle difference of the bidirectional isolated DC converter, based on the relationship between the AC side voltage harmonic components of the DC / AC converter and the AC current harmonic components of the bidirectional isolated DC converter and the phase-shift control angle difference of the bidirectional isolated DC converter.

[0037] The calculation unit is used to calculate the phase-shift control angle difference between the second bridge arm and the first bridge arm of the DC / AC converter, the phase-shift control angle difference between the third bridge arm and the first bridge arm of the AC / DC converter, and the phase-shift control angle difference between the fourth bridge arm and the first bridge arm of the AC / DC converter, based on the obtained DC-side voltage of the DC / AC converter, the DC-side voltage of the AC / DC converter, the turns ratio of the high-frequency transformer, and the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase-shift control angle difference of the bidirectional isolated DC-DC converter.

[0038] The computing unit is specifically used for:

[0039] When V in / mV out When the value is greater than 1, the phase shift control angle difference between the second bridge arm and the first bridge arm is calculated based on the DC-side voltage of the DC / AC converter, the DC-side voltage of the AC / DC converter, and the turns ratio of the high-frequency transformer. The phase shift control angle difference between the third bridge arm and the first bridge arm and the phase shift control angle difference between the fourth bridge arm and the first bridge arm are calculated based on the DC-side voltage of the DC / AC converter, the turns ratio of the high-frequency transformer, and the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC-DC converter.

[0040] When V in / mV out When <1, the phase shift control angle difference between the second bridge arm and the first bridge arm in the DC / AC converter is determined to be 0. Based on the DC side voltage of the DC / AC converter, the turns ratio of the high-frequency transformer, and the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC converter, the phase shift control angle difference between the third bridge arm and the first bridge arm and the phase shift control angle difference between the fourth bridge arm and the first bridge arm are calculated.

[0041] Among them, V in V is the DC-side voltage of the DC / AC converter. out denoted as AC side voltage of the AC / DC converter, and m is the turns ratio of the high-frequency transformer in the bidirectional isolated DC converter.

[0042] When V in / mV out When the value is greater than 1, the calculation unit determines the phase shift control angle difference between the second bridge arm and the first bridge arm using the following formula:

[0043]

[0044] In the formula, α1 is the phase shift control angle difference between the second bridge arm and the first bridge arm in the DC / AC converter, and Vin V is the DC-side voltage of the DC / AC converter. out This is the DC-side voltage of the AC / DC converter.

[0045] The computing unit is specifically used for:

[0046] When V in / mV out When >1, α2 = α3 is satisfied, and And by substituting α2=α3 into the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC converter, the phase shift control angle difference between the third bridge arm and the first bridge arm and the phase shift control angle difference between the fourth bridge arm and the first bridge arm are obtained.

[0047] When V in / mV out When <1, α2=α3-2arccos(V) is satisfied. out_ref / V out ), set α1=0 and α2=α3-2arccos(V out_ref / V out Substituting the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC converter, we obtain the phase shift control angle difference between the third bridge arm and the first bridge arm and the phase shift control angle difference between the fourth bridge arm and the first bridge arm.

[0048] Where α2 is the phase shift control angle difference between the third bridge arm and the first bridge arm, α3 is the phase shift control angle difference between the fourth bridge arm and the first bridge arm, and V out_ref This is the reference value for the DC-side voltage of the AC / DC converter.

[0049] The determining unit determines the relationship between the AC side voltage harmonic components of the DC / AC converter and the AC / DC converter, and the AC current harmonic components of the bidirectional isolated DC converter and the phase shift control angle difference of the bidirectional isolated DC converter, according to the following formula:

[0050]

[0051] In the formula, The AC voltage of the DC / AC converter has a 2n+1th harmonic component. The AC voltage of the AC / DC converter has a 2n+1th harmonic component. The AC current of the bidirectional isolated DC-DC converter is the 2n+1th harmonic component, C is the equivalent capacitance of the high-frequency transformer, and L is the 2n+1st harmonic component. S ω is the leakage inductance of the high-frequency transformer, ω is the angular velocity of the switching frequency, and j is a complex unit.

[0052] The determining unit determines the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC converter according to the following formula:

[0053]

[0054] In the formula, P ab(2n+1) P is the active power of the DC / AC converter under the 2n+1th harmonic. cd(2n+1) X represents the active power of the AC / DC converter under the 2n+1th harmonic. s(2n+1) X is an intermediate quantity, and X s(2n+1) =(2n+1)ωL s -(1 / (2n+1)ωC).

[0055] The technical solution provided by this invention has the following beneficial effects:

[0056] The voltage compensation control method for a bidirectional isolated DC-DC converter provided by this invention obtains the active power transmitted by the DC / AC converter and the AC / DC converter in the bidirectional isolated DC-DC converter. When the voltages on both sides of the bidirectional isolated DC-DC converter are mismatched, the phase-shift control angle difference of the bidirectional isolated DC-DC converter is calculated based on the active power. Voltage compensation is performed on the DC / AC converter and the AC / DC converter based on the phase-shift control angle difference of the bidirectional isolated DC-DC converter. The voltage mismatch compensation control of the bidirectional isolated DC-DC converter is realized based on the phase-shift control angle difference of the bidirectional isolated DC-DC converter, which improves the overall operating efficiency of the bidirectional isolated DC-DC converter and enhances its operating performance.

[0057] The technical solution provided by this invention obtains the phasors of a bidirectional isolated DC-DC converter under phase-shift control through phasor analysis, and then determines the voltage matching situation on both sides of the converter through the phasors of the bidirectional isolated DC-DC converter. Voltage matching control of the bidirectional isolated DC-DC converter is achieved by introducing internal phase shift. Attached Figure Description

[0058] Figure 1 This is a flowchart of the voltage compensation control method for a bidirectional isolated DC-DC converter in an embodiment of the present invention;

[0059] Figure 2 V is an embodiment of the present invention. in / mV out >1, V in =V in_ref And mV out <mV out_ref The compensation control vector diagram;

[0060] Figure 3 V is an embodiment of the present invention. in / mV out>1, V in >V in_ref And mV out >mV out_ref The compensation control vector diagram;

[0061] Figure 4 V is an embodiment of the present invention. in / mV out >1, V in >V in_ref And mV out =mV out_ref The compensation control vector diagram;

[0062] Figure 5 V is an embodiment of the present invention. in / mV out >1, V in >V in_ref And mV out <mV out_ref The compensation control vector diagram;

[0063] Figure 6 V is an embodiment of the present invention. in / mV out >1, V in <V in_ref And mV out <mV out_ref The compensation control vector diagram;

[0064] Figure 7 V is an embodiment of the present invention. in / mV out <1, V in =V in_ref And mV out >mV out_ref The compensation control vector diagram;

[0065] Figure 8 V is an embodiment of the present invention. in / mV out <1, V in <V in_ref And mV out >mV out_ref The compensation control vector diagram;

[0066] Figure 9 V is an embodiment of the present invention. in / mV out <1, V in <V in_ref And mV out =mV out_ref The compensation control vector diagram;

[0067] Figure 10 V is an embodiment of the present invention. in / mV out <1, V in <V in_ref And mV out <mV out_ref The compensation control vector diagram;

[0068] Figure 11 V is an embodiment of the present invention. in / mV out <1, V in <V in_ref And mV out >mV out_ref The compensation control vector diagram;

[0069] Figure 12 This is a topology diagram of a bidirectional isolated DC-DC converter in an embodiment of the present invention. Detailed Implementation

[0070] The present invention will now be described in further detail with reference to the accompanying drawings.

[0071] Example 1

[0072] Embodiment 1 of the present invention provides a voltage compensation control method for a bidirectional isolated DC-DC converter, the specific flowchart of which is shown below. Figure 1 As shown, the specific process is as follows:

[0073] S101: Obtain the active power transmitted by the DC / AC converter and the AC / DC converter in the bidirectional isolated DC-DC converter.

[0074] S102: When the voltages on both sides of the bidirectional isolated DC-DC converter are mismatched, calculate the phase shift control angle difference of the bidirectional isolated DC-DC converter based on the active power;

[0075] S103: Voltage compensation for DC / AC converters and AC / DC converters based on phase shift control angle difference.

[0076] The topology diagram of the bidirectional isolated DC-DC converter in this embodiment of the invention is as follows: Figure 12 As shown, the bidirectional isolated DC-DC converter includes a DC / AC converter, a first resonant unit, a high-frequency transformer T, a second resonant unit, and an AC / DC converter. The DC / AC converter includes a first bridge arm and a second bridge arm, with switches S1 and S3 forming the first bridge arm and switches S2 and S4 forming the second bridge arm. The AC / DC converter includes a third bridge arm and a fourth bridge arm, with switches Q1 and Q3 forming the third bridge arm and switches Q2 and Q4 forming the fourth bridge arm. in V is the DC-side voltage of the DC / AC converter.out This refers to the AC side voltage of the AC / DC converter.

[0077] The phase shift control angle difference of a bidirectional isolated DC-DC converter is calculated based on active power, including:

[0078] The relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase-shift control angle difference of the bidirectional isolated DC converter is determined based on the relationship between the AC side voltage harmonic components of the DC / AC converter and the AC current harmonic components of the bidirectional isolated DC converter and the phase-shift control angle difference of the bidirectional isolated DC converter.

[0079] Based on the obtained DC-side voltage of the DC / AC converter, DC-side voltage of the AC / DC converter, turns ratio of the high-frequency transformer, and the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase-shift control angle difference of the bidirectional isolated DC-DC converter, the phase-shift control angle difference between the second bridge arm and the first bridge arm of the DC / AC converter, the phase-shift control angle difference between the third bridge arm and the first bridge arm of the AC / DC converter, and the phase-shift control angle difference between the fourth bridge arm and the first bridge arm of the AC / DC converter are calculated.

[0080] Based on the obtained DC-side voltage of the DC / AC converter, DC-side voltage of the AC / DC converter, turns ratio of the high-frequency transformer, and the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase-shift control angle difference of the bidirectional isolated DC-DC converter, the phase-shift control angle differences between the second bridge arm and the first bridge arm of the DC / AC converter, the phase-shift control angle differences between the third bridge arm and the first bridge arm of the AC / DC converter, and the phase-shift control angle differences between the fourth bridge arm and the first bridge arm of the AC / DC converter are calculated, and the following two cases are considered:

[0081] When V in / mV out When the value is greater than 1, the phase shift control angle difference between the second bridge arm and the first bridge arm is calculated based on the DC-side voltage of the DC / AC converter, the DC-side voltage of the AC / DC converter, and the turns ratio of the high-frequency transformer. The phase shift control angle difference between the third bridge arm and the first bridge arm and the fourth bridge arm and the first bridge arm are calculated based on the DC-side voltage of the DC / AC converter, the turns ratio of the high-frequency transformer, and the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC-DC converter.

[0082] When V in / mV outWhen <1, the phase shift control angle difference between the second bridge arm and the first bridge arm in the DC / AC converter is determined to be 0. Based on the DC side voltage of the DC / AC converter, the turns ratio of the high-frequency transformer, and the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC converter, the phase shift control angle difference between the third bridge arm and the first bridge arm and the phase shift control angle difference between the fourth bridge arm and the first bridge arm are calculated.

[0083] Among them, V in V is the DC-side voltage of the DC / AC converter. out denoted as AC side voltage of the AC / DC converter, and m is the turns ratio of the high-frequency transformer in the bidirectional isolated DC converter.

[0084] When V in / mVo ut When the difference is greater than 1, the phase shift control angle difference between the second arm and the first arm is determined by the following formula:

[0085]

[0086] In the formula, α1 is the phase shift control angle difference between the second bridge arm and the first bridge arm in the DC / AC converter, and V in V is the DC-side voltage of the DC / AC converter. out This is the DC-side voltage of the AC / DC converter.

[0087] Based on the DC-side voltage of the DC / AC converter, the turns ratio of the high-frequency transformer, and the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase-shift control angle difference of the bidirectional isolated DC-DC converter, the phase-shift control angle difference between the third arm and the first arm and the fourth arm and the first arm are calculated, including:

[0088] When V in / mV out When >1, α2 = α3 is satisfied, and And by substituting α2=α3 into the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC converter, the phase shift control angle difference between the third bridge arm and the first bridge arm and the phase shift control angle difference between the fourth bridge arm and the first bridge arm are obtained.

[0089] When V in / mV out When <1, α2=α3-2arccos(V) is satisfied. out_ref / V out ), set α1=0 and α2=α3-2arccos(V out_ref / V outSubstituting the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC converter, we obtain the phase shift control angle difference between the third bridge arm and the first bridge arm and the phase shift control angle difference between the fourth bridge arm and the first bridge arm.

[0090] Where α2 is the phase shift control angle difference between the third bridge arm and the first bridge arm, α3 is the phase shift control angle difference between the fourth bridge arm and the first bridge arm, and V out_ref This is the reference value for the DC-side voltage of the AC / DC converter.

[0091] The phase shift control angle difference between the second bridge arm and the first bridge arm in a DC / AC converter is defined as α1; the phase shift control angle difference between the third bridge arm and the first bridge arm is defined as α2; and the phase shift control angle difference between the fourth bridge arm and the first bridge arm is defined as α3. The phase shift angles corresponding to the three phase shift control methods are defined as follows:

[0092] 1) Traditional single-phase-shift control method: There is no internal phase-shift control between the DC / AC converter and the AC / DC converter. There is only external phase-shift control between the DC / AC converter and the AC / DC converter. In this case, α1=0 and α2=α3.

[0093] 2) Extended phase-shift control: The DC / AC converter or AC / DC converter has internal phase-shift control, and there is external phase-shift control between the DC / AC converter and the AC / DC converter. This corresponds to α1≠0 and α2=α3, or α1=0 and α2≠α3.

[0094] 3) Dual phase-shift control: Both the DC / AC converter and the AC / DC converter have internal phase-shift control, and the internal phase-shift angles are equal. There is external phase-shift control between the DC / AC converter and the AC / DC converter. In this case, α1≠0 and α1=α3-α2.

[0095] Based on the above definitions, the AC side voltage of the DC / AC converter and the AC side voltage of the AC / DC converter under phase-shift control are expressed as follows:

[0096]

[0097] Among them, V ab (t) represents the AC side voltage of the DC / AC converter, V cd (t) represents the AC side voltage of the AC / DC converter. Using Kirchhoff's voltage law to describe the AC / AC link of the converter, the dynamic equation can be derived. m represents the turns ratio of the high-frequency transformer.

[0098] Therefore, the relationship between the AC side voltage harmonic components of the DC / AC converter and the AC / DC converter, as well as the AC current harmonic components of the bidirectional isolated DC converter and the phase shift control angle difference of the bidirectional isolated DC converter, can be determined by the following formula:

[0099]

[0100] In the formula, The AC voltage of the DC / AC converter has a 2n+1th harmonic component. The AC voltage of the AC / DC converter has a 2n+1th harmonic component. The AC current of the bidirectional isolated DC-DC converter is the 2n+1th harmonic component, C is the equivalent capacitance of the high-frequency transformer, and L is the 2n+1st harmonic component. S ω is the leakage inductance of the high-frequency transformer, ω is the angular velocity of the switching frequency, and j is a complex unit.

[0101] Therefore, the phasor equation for the AC element (2n+1)th of the converter can be obtained as follows:

[0102] Furthermore, the expressions for the AC voltage (2n+1)th components of the first, second, third, and fourth bridge arms are as follows:

[0103]

[0104] Let (2n+1)th be the AC voltage component of the first bridge arm. The AC voltage (2n+1)th component of the second bridge arm. The AC voltage (2n+1)th component of the third bridge arm. The AC voltage (2n+1)th component of the fourth bridge arm.

[0105] The expressions for the apparent power, active power, and reactive power (2n+1)th components of HB1 and HB2 are as follows:

[0106]

[0107] Among them, Q ab(2n+1) Q represents the reactive power of the DC / AC converter under the 2n+1th harmonic. cd(2n+1) Let Q be the reactive power of the AC / DC converter under the 2n+1th harmonic, and Q ab(2n+1) +Q cd(2n+1) =Q L(2n+1) Q L(2n+1) This represents the reactive power of the resonant unit.

[0108] Therefore, the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC converter can be determined by the following formula:

[0109]

[0110] In the formula, P ab(2n+1) P is the active power of the DC / AC converter under the 2n+1th harmonic. cd(2n+1) X represents the active power of the AC / DC converter under the 2n+1th harmonic. s(2n+1) X is an intermediate quantity, and X s(2n+1) =(2n+1)ωL s -(1 / (2n+1)ωC).

[0111] In Embodiment 1 of the present invention, the DC voltage variations on both sides of the DC converter are shown in Table 1:

[0112] Table 1:

[0113]

[0114]

[0115] When V in / mV out When V = 1, the bidirectional isolated DC-DC converter has no voltage mismatch and requires no compensation. The calculation of the phase shift control angle difference of the bidirectional isolated DC-DC converter is specifically divided into V... in / mV out >1 and V in / mV out <1. In two cases, the specific process of voltage compensation control method for bidirectional isolated DC-DC converter is described below:

[0116] (1)V in / mV out >1 can be specifically divided into the following situations:

[0117] 1-1)V in / mV out >1, V in =V in_ref And mV out <mV out_ref :

[0118] The phase-shift control angle difference between the second and first bridge arms is calculated based on the DC-side voltage of the DC / AC converter, the DC-side voltage of the AC / DC converter, and the turns ratio of the high-frequency transformer. Furthermore, the phase-shift control angle differences between the third and fourth bridge arms are calculated based on the relationship between the DC-side voltage of the DC / AC converter, the turns ratio of the high-frequency transformer, the active power transmitted by the DC / AC converter and the AC / DC converter, and the phase-shift control angle difference of the bidirectional isolated DC-DC converter. V in_ref V is the reference value for the DC-side voltage of the DC / AC converter. out_ref This is the reference value for the DC-side voltage of the AC / DC converter; the phase shift control angle difference between the third bridge arm and the first bridge arm is equal to the phase shift control angle difference between the fourth bridge arm and the first bridge arm, i.e., α2 = α3. And by substituting α2 = α3 into the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC-DC converter, we can obtain the phase shift control angle difference between the third arm and the first arm, and the phase shift control angle difference between the fourth arm and the first arm, V in / mV out >1, V in =V in_ref And mV out <mV out_ref The compensation control vector diagram is as follows Figure 2 As shown;

[0119] 1-2)V in / mV out >1, V in >V in_ref And mV out >mV out_ref :

[0120] The phase-shift control angle difference between the second and first bridge arms is calculated based on the DC-side voltage of the DC / AC converter, the DC-side voltage of the AC / DC converter, and the turns ratio of the high-frequency transformer. Furthermore, the phase-shift control angle differences between the third and fourth bridge arms are calculated based on the relationship between the DC-side voltage of the DC / AC converter, the turns ratio of the high-frequency transformer, the active power transmitted by the DC / AC converter and the AC / DC converter, and the phase-shift control angle difference of the bidirectional isolated DC-DC converter. V in_ref V is the reference value for the DC-side voltage of the DC / AC converter. out_ref This is the reference value for the DC-side voltage of the AC / DC converter; the phase shift control angle difference between the third bridge arm and the first bridge arm is equal to the phase shift control angle difference between the fourth bridge arm and the first bridge arm, i.e., α2 = α3. And by substituting α2 = α3 into the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC-DC converter, we can obtain the phase shift control angle difference between the third arm and the first arm, and the phase shift control angle difference between the fourth arm and the first arm, V in / mV out >1, V in >V in_ref And mV out >mV out_ref The compensation control vector diagram is as follows Figure 3 As shown;

[0121] 1-3)V in / mV out >1, V in >V in_ref And mV out =mV out_ref :

[0122] The phase-shift control angle difference between the second and first bridge arms is calculated based on the DC-side voltage of the DC / AC converter, the DC-side voltage of the AC / DC converter, and the turns ratio of the high-frequency transformer. Furthermore, the phase-shift control angle differences between the third and fourth bridge arms are calculated based on the relationship between the DC-side voltage of the DC / AC converter, the turns ratio of the high-frequency transformer, the active power transmitted by the DC / AC converter and the AC / DC converter, and the phase-shift control angle difference of the bidirectional isolated DC-DC converter. V in_ref V is the reference value for the DC-side voltage of the DC / AC converter. out_ref This is the reference value for the DC-side voltage of the AC / DC converter; the phase shift control angle difference between the third bridge arm and the first bridge arm is equal to the phase shift control angle difference between the fourth bridge arm and the first bridge arm, i.e., α2 = α3. And by substituting α2 = α3 into the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC-DC converter, we can obtain the phase shift control angle difference between the third arm and the first arm, and the phase shift control angle difference between the fourth arm and the first arm, V in / mV out >1, V in >V in_ref And mV out =mV out_ref The compensation control vector diagram is as follows Figure 4 As shown;

[0123] 1-4)V in / mV out >1, V in >V in_ref And mV out<mV out_ref Based on the DC-side voltage of the DC / AC converter, the DC-side voltage of the AC / DC converter, and the turns ratio of the high-frequency transformer, the phase-shift control angle difference between the second and first bridge arms is calculated. Furthermore, based on the DC-side voltage of the DC / AC converter, the turns ratio of the high-frequency transformer, and the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase-shift control angle difference of the bidirectional isolated DC-DC converter, the phase-shift control angle differences between the third and fourth bridge arms and the first bridge arm are calculated. V in_ref V is the reference value for the DC-side voltage of the DC / AC converter. out_ref This is the reference value for the DC-side voltage of the AC / DC converter; the phase shift control angle difference between the third bridge arm and the first bridge arm is equal to the phase shift control angle difference between the fourth bridge arm and the first bridge arm, i.e., α2 = α3. And by substituting α2 = α3 into the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC-DC converter, we can obtain the phase shift control angle difference between the third arm and the first arm, and the phase shift control angle difference between the fourth arm and the first arm, V in / mV out >1, V in >V in_ref And mV out <mV out_ref The compensation control vector diagram is as follows Figure 5 As shown;

[0124] 1-5)V in / mV out >1, V in <V in_ref And mV out <mV out_ref Based on the DC-side voltage of the DC / AC converter, the DC-side voltage of the AC / DC converter, and the turns ratio of the high-frequency transformer, the phase-shift control angle difference between the second and first bridge arms is calculated. Furthermore, based on the DC-side voltage of the DC / AC converter, the turns ratio of the high-frequency transformer, and the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase-shift control angle difference of the bidirectional isolated DC-DC converter, the phase-shift control angle differences between the third and fourth bridge arms and the first bridge arm are calculated. V in_ref V is the reference value for the DC-side voltage of the DC / AC converter. out_ref This is the reference value for the DC-side voltage of the AC / DC converter; the phase shift control angle difference between the third bridge arm and the first bridge arm is equal to the phase shift control angle difference between the fourth bridge arm and the first bridge arm, i.e., α2 = α3. And by substituting α2 = α3 into the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC-DC converter, we can obtain the phase shift control angle difference between the third arm and the first arm, and the phase shift control angle difference between the fourth arm and the first arm, V in / mV out >1, V in >V in_ref And mV out <mV out_ref The compensation control vector diagram is as follows Figure 6 As shown;

[0125] (2)V in / mV out <1 can be specifically divided into the following situations:

[0126] 2-1)V in / mV out <1, V in =V in_ref And mV out >mV out_ref The phase shift control angle difference between the second bridge arm and the first bridge arm in the DC / AC converter is determined to be 0, i.e., α1 = 0. Based on the DC-side voltage of the DC / AC converter, the turns ratio of the high-frequency transformer, and the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC-AC converter, the phase shift control angle differences between the third bridge arm and the first bridge arm, and the phase shift control angle differences between the fourth bridge arm and the first bridge arm are calculated, satisfying α2 = α3 - 2arccos(V out_ref / V out ), set α1=0 and α2=α3-2arccos(V out_ref / V out Substituting the active power transmitted by the DC / AC converter and the AC / DC converter into the relationship between the phase shift control angle difference of the bidirectional isolated DC-DC converter, we obtain the phase shift control angle difference between the third bridge arm and the first bridge arm, and the phase shift control angle difference between the fourth bridge arm and the first bridge arm; V in / mV out <1, V in =V in_ref And mV out >mV out_ref The compensation control vector diagram is as follows Figure 7 As shown;

[0127] 2-2)V in / mV out <1, V in <V in_ref And mV out >mV out_refThe phase shift control angle difference between the second bridge arm and the first bridge arm in the DC / AC converter is determined to be 0, i.e., α1 = 0. Based on the DC-side voltage of the DC / AC converter, the turns ratio of the high-frequency transformer, and the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC-AC converter, the phase shift control angle differences between the third bridge arm and the first bridge arm, and the phase shift control angle differences between the fourth bridge arm and the first bridge arm are calculated, satisfying α2 = α3 - 2arccos(V out_ref / V out ), set α1=0 and α2=α3-2arccos(V out_ref / V out Substituting the active power transmitted by the DC / AC converter and the AC / DC converter into the relationship between the phase shift control angle difference of the bidirectional isolated DC-DC converter, we obtain the phase shift control angle difference between the third bridge arm and the first bridge arm, and the phase shift control angle difference between the fourth bridge arm and the first bridge arm; V in / mV out <1, V in <V in_ref And mVo ut >mV out_ref The compensation control vector diagram is as follows Figure 8 As shown;

[0128] 2-3)V in / mV out <1, V in <V in_ref And mV out =mV out_ref The phase shift control angle difference between the second bridge arm and the first bridge arm in the DC / AC converter is determined to be 0, i.e., α1 = 0. Based on the DC-side voltage of the DC / AC converter, the turns ratio of the high-frequency transformer, and the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC-AC converter, the phase shift control angle differences between the third bridge arm and the first bridge arm, and the phase shift control angle differences between the fourth bridge arm and the first bridge arm are calculated, satisfying α2 = α3 - 2arccos(V out_ref / V out ), set α1=0 and α2=α3-2arccos(V out_ref / V out Substituting the active power transmitted by the DC / AC converter and the AC / DC converter into the relationship between the phase shift control angle difference of the bidirectional isolated DC-DC converter, we obtain the phase shift control angle difference between the third bridge arm and the first bridge arm, and the phase shift control angle difference between the fourth bridge arm and the first bridge arm; V in / mV out <1, V in <V in_refAnd mV out =mV out_ref The compensation control vector diagram is as follows Figure 9 As shown;

[0129] 2-4)V in / mV out <1, V in <V in_ref And mV out <mV out_ref The phase shift control angle difference between the second bridge arm and the first bridge arm in the DC / AC converter is determined to be 0, i.e., α1 = 0. Based on the DC-side voltage of the DC / AC converter, the turns ratio of the high-frequency transformer, and the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC-AC converter, the phase shift control angle differences between the third bridge arm and the first bridge arm, and the phase shift control angle differences between the fourth bridge arm and the first bridge arm are calculated, satisfying α2 = α3 - 2arccos(V out_ref / V out ), set α1=0 and α2=α3-2arccos(V out_ref / V out Substituting the active power transmitted by the DC / AC converter and the AC / DC converter into the relationship between the phase shift control angle difference of the bidirectional isolated DC-DC converter, we obtain the phase shift control angle difference between the third bridge arm and the first bridge arm, and the phase shift control angle difference between the fourth bridge arm and the first bridge arm; V in / mV out <1, V in <V in_ref And mV out <mV out_ref The compensation control vector diagram is as follows Figure 10 As shown;

[0130] 2-5)V in / mV out <1, V in <V in_ref And mV out >mV out_ref The phase shift control angle difference between the second bridge arm and the first bridge arm in the DC / AC converter is determined to be 0, i.e., α1 = 0. Based on the DC-side voltage of the DC / AC converter, the turns ratio of the high-frequency transformer, and the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC-AC converter, the phase shift control angle differences between the third bridge arm and the first bridge arm, and the phase shift control angle differences between the fourth bridge arm and the first bridge arm are calculated, satisfying α2 = α3 - 2arccos(V out_ref / V out ), set α1=0 and α2=α3-2arccos(Vout_ref / V out Substituting the active power transmitted by the DC / AC converter and the AC / DC converter into the relationship between the phase shift control angle difference of the bidirectional isolated DC-DC converter, we obtain the phase shift control angle difference between the third bridge arm and the first bridge arm, and the phase shift control angle difference between the fourth bridge arm and the first bridge arm; V in / mV out <1, V in <V in_ref And mV out >mV out_ref The compensation control vector diagram is as follows Figure 11 As shown.

[0131] In Embodiment 1 of this invention, the phasor expression and control phasor diagram of a bidirectional isolated DC-DC converter under phase-shift control are established by phasor analysis. Then, the voltage matching on both sides of the converter is analyzed by phasor expression, and voltage matching control is achieved by introducing internal phase shift.

[0132] In the above S103, voltage compensation is performed on the DC / AC converter and AC / DC converter based on the phase shift control angle difference. Specifically, the phase shift control angle difference of the bidirectional isolated DC converter is used to make the AC side voltage amplitude of the DC / AC converter equal to that of the AC side voltage amplitude of the AC / DC converter, thereby achieving voltage matching on both sides of the bidirectional isolated DC converter and meeting the requirements for transmitting active power of the bidirectional isolated DC converter.

[0133] Example 2

[0134] Based on the same inventive concept, Embodiment 2 of the present invention also provides a bidirectional isolated DC-DC converter voltage compensation control device, comprising:

[0135] The acquisition module is used to acquire the active power transmitted by the DC / AC converter and the AC / DC converter in the bidirectional isolated DC-DC converter.

[0136] The calculation module is used to calculate the phase shift control angle difference of the bidirectional isolated DC-DC converter based on the active power.

[0137] The control module is used to control the DC / AC converter and the AC / DC converter based on the phase shift control angle difference.

[0138] The calculation module includes:

[0139] The determining unit is used to determine the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase-shift control angle difference of the bidirectional isolated DC converter, based on the relationship between the AC side voltage harmonic components of the DC / AC converter and the AC current harmonic components of the bidirectional isolated DC converter and the phase-shift control angle difference of the bidirectional isolated DC converter.

[0140] The calculation unit is used to calculate the phase-shift control angle difference between the second bridge arm and the first bridge arm of the DC / AC converter, the phase-shift control angle difference between the third bridge arm and the first bridge arm of the AC / DC converter, and the phase-shift control angle difference between the fourth bridge arm and the first bridge arm of the AC / DC converter, based on the obtained DC-side voltage of the DC / AC converter, the DC-side voltage of the AC / DC converter, the turns ratio of the high-frequency transformer, and the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase-shift control angle difference of the bidirectional isolated DC-DC converter.

[0141] The computing unit is specifically used for:

[0142] When V in / mV out When the value is greater than 1, the phase shift control angle difference between the second bridge arm and the first bridge arm is calculated based on the DC-side voltage of the DC / AC converter, the DC-side voltage of the AC / DC converter, and the turns ratio of the high-frequency transformer. The phase shift control angle difference between the third bridge arm and the first bridge arm and the fourth bridge arm and the first bridge arm are calculated based on the DC-side voltage of the DC / AC converter, the turns ratio of the high-frequency transformer, and the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC-DC converter.

[0143] When V in / mV out When <1, the phase shift control angle difference between the second bridge arm and the first bridge arm in the DC / AC converter is determined to be 0. Based on the DC side voltage of the DC / AC converter, the turns ratio of the high-frequency transformer, and the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC converter, the phase shift control angle difference between the third bridge arm and the first bridge arm and the phase shift control angle difference between the fourth bridge arm and the first bridge arm are calculated.

[0144] Among them, V in V is the DC-side voltage of the DC / AC converter. out denoted as AC side voltage of the AC / DC converter, and m is the turns ratio of the high-frequency transformer in the bidirectional isolated DC converter.

[0145] When V in / mV outWhen the value is greater than 1, the calculation unit determines the phase shift control angle difference between the second bridge arm and the first bridge arm using the following formula:

[0146]

[0147] In the formula, α1 is the phase shift control angle difference between the second bridge arm and the first bridge arm in the DC / AC converter, and V in V is the DC-side voltage of the DC / AC converter. out This is the DC-side voltage of the AC / DC converter.

[0148] The computing unit is specifically used for:

[0149] When V in / mV out When >1, α2 = α3 is satisfied, and And by substituting α2=α3 into the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC converter, the phase shift control angle difference between the third bridge arm and the first bridge arm and the phase shift control angle difference between the fourth bridge arm and the first bridge arm are obtained.

[0150] When V in / mV out When <1, α2=α3-2arccos(V) is satisfied. out_ref / V out ), set α1=0 and α2=α3-2arccos(V out_ref / V out Substituting the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC converter, we obtain the phase shift control angle difference between the third bridge arm and the first bridge arm and the phase shift control angle difference between the fourth bridge arm and the first bridge arm.

[0151] Where α2 is the phase shift control angle difference between the third bridge arm and the first bridge arm, α3 is the phase shift control angle difference between the fourth bridge arm and the first bridge arm, and V out_ref This is the reference value for the DC-side voltage of the AC / DC converter.

[0152] The relationship between the AC side voltage harmonic components of the DC / AC converter and the AC / DC converter, as well as the AC current harmonic components of the bidirectional isolated DC converter and the phase shift control angle difference of the bidirectional isolated DC converter, is determined by the following formula:

[0153]

[0154] In the formula, The AC voltage of the DC / AC converter has a 2n+1th harmonic component. The AC voltage of the AC / DC converter has a 2n+1th harmonic component. The AC current of the bidirectional isolated DC-DC converter is the 2n+1th harmonic component, C is the equivalent capacitance of the high-frequency transformer, and L is the 2n+1st harmonic component. S ω is the leakage inductance of the high-frequency transformer, ω is the angular velocity of the switching frequency, and j is a complex unit.

[0155] The relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC converter is determined by the following formula:

[0156]

[0157] In the formula, P ab(2n+1) P is the active power of the DC / AC converter under the 2n+1th harmonic. cd(2n+1) X represents the active power of the AC / DC converter under the 2n+1th harmonic. s(2n+1) X is an intermediate quantity, and X s(2n+1) =(2n+1)ωL s -(1 / (2n+1)ωC).

[0158] For ease of description, the various parts of the above device are described separately as modules or units based on their functions. Of course, in implementing this application, the functions of each module or unit can be implemented in one or more software or hardware components.

[0159] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0160] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0161] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0162] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0163] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Those skilled in the art can still make modifications or equivalent substitutions to the specific implementation of the present invention by referring to the above embodiments. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention are within the protection scope of the present invention pending approval.

Claims

1. A compensation control method for a bidirectional isolated DC-DC converter, characterized in that, include: Obtain the active power transmitted by the DC / AC converter and the AC / DC converter in a bidirectional isolated DC-DC converter. When the voltages on both sides of the bidirectional isolated DC-DC converter are mismatched, the phase shift control angle difference of the bidirectional isolated DC-DC converter is calculated based on the active power. Voltage compensation is performed on the DC / AC converter and AC / DC converter based on the phase shift control angle difference; The calculation of the phase shift control angle difference of the bidirectional isolated DC-DC converter based on the active power includes: The relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase-shift control angle difference of the bidirectional isolated DC converter is determined based on the relationship between the AC side voltage harmonic components of the DC / AC converter and the AC current harmonic components of the bidirectional isolated DC converter and the phase-shift control angle difference of the bidirectional isolated DC converter. Based on the obtained DC-side voltage of the DC / AC converter, DC-side voltage of the AC / DC converter, turns ratio of the high-frequency transformer, and the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase-shift control angle difference of the bidirectional isolated DC-DC converter, the phase-shift control angle difference between the second bridge arm and the first bridge arm of the DC / AC converter, the phase-shift control angle difference between the third bridge arm and the first bridge arm of the AC / DC converter, and the phase-shift control angle difference between the fourth bridge arm and the first bridge arm of the AC / DC converter are calculated. The calculation of the phase-shift control angle differences between the second and first arms of the DC / AC converter, the third and first arms of the AC / DC converter, and the fourth and first arms of the AC / DC converter based on the obtained DC-side voltage of the DC / AC converter, the DC-side voltage of the AC / DC converter, the turns ratio of the high-frequency transformer, and the relationship between the active power transmitted by the DC / AC converter and the phase-shift control angle difference of the bidirectional isolated DC-AC converter includes: when At that time, the phase shift control angle difference between the second bridge arm and the first bridge arm is calculated based on the DC-side voltage of the DC / AC converter, the DC-side voltage of the AC / DC converter, and the turns ratio of the high-frequency transformer. The phase shift control angle difference between the third bridge arm and the first bridge arm and the phase shift control angle difference between the fourth bridge arm and the first bridge arm are calculated based on the DC-side voltage of the DC / AC converter, the turns ratio of the high-frequency transformer, and the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC-DC converter. when When the phase shift control angle difference between the second bridge arm and the first bridge arm in the DC / AC converter is determined to be 0, the phase shift control angle difference between the third bridge arm and the first bridge arm and the phase shift control angle difference between the fourth bridge arm and the first bridge arm are calculated based on the DC side voltage of the DC / AC converter, the turns ratio of the high-frequency transformer, and the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC converter. in, V in This refers to the DC-side voltage of the DC / AC converter. V out This refers to the AC side voltage of the AC / DC converter. m The turns ratio of the high-frequency transformer in a bidirectional isolated DC-DC converter; when At that time, the phase shift control angle difference between the second bridge arm and the first bridge arm is determined by the following formula: In the formula, This represents the phase shift control angle difference between the second bridge arm and the first bridge arm in the DC / AC converter. This refers to the DC-side voltage of the DC / AC converter. This is the DC-side voltage of the AC / DC converter.

2. The voltage compensation control method for a bidirectional isolated DC-DC converter according to claim 1, characterized in that, The calculation of the phase shift control angle difference between the third arm and the first arm, and the phase shift control angle difference between the fourth arm and the first arm, based on the DC-side voltage of the DC / AC converter, the turns ratio of the high-frequency transformer, and the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC-DC converter, includes: when When, satisfy ,Will as well as By substituting the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC converter, the phase shift control angle difference between the third bridge arm and the first bridge arm and the phase shift control angle difference between the fourth bridge arm and the first bridge arm are obtained. when When, satisfy ,Will as well as By substituting the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC converter, the phase shift control angle difference between the third bridge arm and the first bridge arm and the phase shift control angle difference between the fourth bridge arm and the first bridge arm are obtained. in, The difference in phase shift control angle between the third arm and the first arm. The difference in phase shift control angle between the fourth bridge arm and the first bridge arm. This is the reference value for the DC-side voltage of the AC / DC converter.

3. The voltage compensation control method for a bidirectional isolated DC-DC converter according to claim 2, characterized in that, The relationship between the AC side voltage harmonic components of the DC / AC converter and the AC / DC converter, the AC current harmonic components of the bidirectional isolated DC converter, and the phase shift control angle difference of the bidirectional isolated DC converter is determined by the following formula: In the formula, The AC voltage of the DC / AC converter has a 2n+1th harmonic component. The AC voltage of the AC / DC converter has a 2n+1th harmonic component. This refers to the 2n+1th harmonic component of the AC current in a bidirectional isolated DC-DC converter. C This is the equivalent capacitance of a high-frequency transformer. The leakage inductance of the high-frequency transformer. The angular velocity is the switching frequency. j It is a complex unit.

4. The voltage compensation control method for a bidirectional isolated DC-DC converter according to claim 3, characterized in that, The relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC converter is determined by the following formula: In the formula, The active power of the DC / AC converter under the 2n+1th harmonic. The active power of the AC / DC converter under the 2n+1th harmonic. It is an intermediate quantity, and .

5. A voltage compensation control device for a bidirectional isolated DC-DC converter, characterized in that, include: The acquisition module is used to acquire the active power transmitted by the DC / AC converter and the AC / DC converter in the bidirectional isolated DC-DC converter. The calculation module is used to calculate the phase shift control angle difference of the bidirectional isolated DC-DC converter based on the active power when the voltages on both sides of the bidirectional isolated DC-DC converter are mismatched. The control module is used to perform voltage compensation on the DC / AC converter and the AC / DC converter based on the phase shift control angle difference; The computing module includes: The determining unit is used to determine the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase-shift control angle difference of the bidirectional isolated DC converter, based on the relationship between the AC side voltage harmonic components of the DC / AC converter and the AC current harmonic components of the bidirectional isolated DC converter and the phase-shift control angle difference of the bidirectional isolated DC converter. The calculation unit is used to calculate the phase shift control angle difference between the second bridge arm and the first bridge arm of the DC / AC converter, the phase shift control angle difference between the third bridge arm and the first bridge arm of the AC / DC converter, and the phase shift control angle difference between the fourth bridge arm and the first bridge arm of the AC / DC converter based on the obtained DC-side voltage of the DC / AC converter, the DC-side voltage of the AC / DC converter, the turns ratio of the high-frequency transformer, and the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC-DC converter. The computing unit is specifically used for: when At that time, the phase shift control angle difference between the second bridge arm and the first bridge arm is calculated based on the DC-side voltage of the DC / AC converter, the DC-side voltage of the AC / DC converter, and the turns ratio of the high-frequency transformer. The phase shift control angle difference between the third bridge arm and the first bridge arm and the phase shift control angle difference between the fourth bridge arm and the first bridge arm are calculated based on the DC-side voltage of the DC / AC converter, the turns ratio of the high-frequency transformer, and the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC-DC converter. when When the phase shift control angle difference between the second bridge arm and the first bridge arm in the DC / AC converter is determined to be 0, the phase shift control angle difference between the third bridge arm and the first bridge arm and the phase shift control angle difference between the fourth bridge arm and the first bridge arm are calculated based on the DC side voltage of the DC / AC converter, the turns ratio of the high-frequency transformer, and the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC converter. in, V in This refers to the DC-side voltage of the DC / AC converter. V out This refers to the AC side voltage of the AC / DC converter. m The turns ratio of the high-frequency transformer in a bidirectional isolated DC-DC converter; when At that time, the calculation unit determines the phase shift control angle difference between the second bridge arm and the first bridge arm according to the following formula: In the formula, This represents the phase shift control angle difference between the second bridge arm and the first bridge arm in the DC / AC converter. This refers to the DC-side voltage of the DC / AC converter. This is the DC-side voltage of the AC / DC converter.

6. The bidirectional isolated DC-DC converter voltage compensation control device according to claim 5, characterized in that, The computing unit is specifically used for: when When, satisfy ,Will as well as By substituting the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC converter, the phase shift control angle difference between the third bridge arm and the first bridge arm and the phase shift control angle difference between the fourth bridge arm and the first bridge arm are obtained. when When, satisfy ,Will as well as By substituting the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC converter, the phase shift control angle difference between the third bridge arm and the first bridge arm and the phase shift control angle difference between the fourth bridge arm and the first bridge arm are obtained. in, The difference in phase shift control angle between the third arm and the first arm. The difference in phase shift control angle between the fourth bridge arm and the first bridge arm. This is the reference value for the DC-side voltage of the AC / DC converter.

7. The bidirectional isolated DC-DC converter voltage compensation control device according to claim 6, characterized in that, The determining unit determines the relationship between the AC side voltage harmonic components of the DC / AC converter and the AC / DC converter, and the AC current harmonic components of the bidirectional isolated DC converter and the phase shift control angle difference of the bidirectional isolated DC converter, according to the following formula: In the formula, The AC voltage of the DC / AC converter has a 2n+1th harmonic component. The AC voltage of the AC / DC converter has a 2n+1th harmonic component. This refers to the 2n+1th harmonic component of the AC current in a bidirectional isolated DC-DC converter. C This is the equivalent capacitance of a high-frequency transformer. The leakage inductance of the high-frequency transformer. The angular velocity is the switching frequency. j It is a complex unit.

8. The bidirectional isolated DC-DC converter voltage compensation control device according to claim 7, characterized in that, The determining unit determines the relationship between the active power transmitted by the DC / AC converter and the AC / DC converter and the phase shift control angle difference of the bidirectional isolated DC converter according to the following formula: In the formula, The active power of the DC / AC converter under the 2n+1th harmonic. The active power of the AC / DC converter under the 2n+1th harmonic. It is an intermediate quantity, and .

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