Energy conversion device and vehicle

Abstract

The embodiment of the present application provides an energy conversion device and a vehicle, the energy conversion device includes a primary bridge arm module, a filter module, a resonance module, a secondary bridge arm module and a control module; the primary bridge arm module includes: a first bridge arm, a second bridge arm and a third bridge arm, and the secondary bridge arm module includes a fourth bridge arm and a fifth bridge arm; the frequency of the driving signal of the second bridge arm, the frequency of the driving signal of the third bridge arm, the frequency of the driving signal of the fourth bridge arm, and the frequency of the driving signal of the fifth bridge arm are all greater than the frequency of the driving signal of the first bridge arm; the control module determines the phase shift angle of the target bridge arm relative to the reference bridge arm according to the required gain of the energy conversion device, the first sampling current, the second sampling current, the first sampling voltage, and the second sampling voltage, so as to realize the soft switching action and energy control of the switches in the primary bridge arm module and the secondary bridge arm module. The embodiment of the present application can reduce the volume and cost of the energy conversion device.

Description

Technical Field

[0001] The present application relates to the field of electronic circuit technology, and in particular to an energy conversion device and a vehicle. Background Art

[0002] With the development of electric vehicles, on-board chargers have received more and more attention as energy conversion devices for electric vehicles. Energy conversion devices can convert AC power into DC power to charge the high-voltage battery in electric vehicles. Energy conversion devices usually adopt a two-stage architecture of a power factor correction (PFC) module and a direct current / direct current (DC / DC) module. The PFC module and the DC / DC module are decoupled by electrolytic capacitors, which increases the size and cost of the energy conversion device and reduces the power density. Summary of the invention

[0003] The embodiments of the present application provide an energy conversion device and a vehicle, which can reduce the volume and cost of the energy conversion device.

[0004] A first aspect of an embodiment of the present application provides an energy conversion device, including a primary bridge arm module, a filter module, a resonance module, a secondary bridge arm module and a control module; the primary bridge arm module includes: a first bridge arm, a second bridge arm and a third bridge arm, and the secondary bridge arm module includes a fourth bridge arm and a fifth bridge arm; the frequency of the driving signal of the second bridge arm, the frequency of the driving signal of the third bridge arm, the frequency of the driving signal of the fourth bridge arm, and the frequency of the driving signal of the fifth bridge arm are all greater than the frequency of the driving signal of the first bridge arm;

[0005] The first end of the filter module is connected to the first AC end, the second end of the filter module is connected to the bridge arm midpoint of the third bridge arm and the first end of the resonance module, the third end of the filter module is connected to the bridge arm midpoint of the second bridge arm and the second end of the resonance module, and the bridge arm midpoint of the first bridge arm is connected to the second AC end; the third end of the resonance module is connected to the bridge arm midpoint of the fourth bridge arm, and the fourth end of the resonance module is connected to the bridge arm midpoint of the fifth bridge arm; the first end of the first bridge arm is connected to the first end of the second bridge arm and the first end of the third bridge arm, the second end of the first bridge arm is connected to the second end of the second bridge arm and the second end of the third bridge arm, the first end of the fourth bridge arm is connected to the first end of the fifth bridge arm and the first DC end, and the second end of the fourth bridge arm is connected to the second end of the fifth bridge arm and the second DC end;

[0006] The control module determines the phase shift angle of the target bridge arm relative to the reference bridge arm according to the required gain of the energy conversion device, the first sampled current, the second sampled current, the first sampled voltage, and the second sampled voltage, so as to realize the soft switching action of the switches in the primary bridge arm module and the secondary bridge arm module;

[0007] The reference bridge arm is one of the second bridge arm, the third bridge arm, the fourth bridge arm and the fifth bridge arm, and the target bridge arm is the bridge arm other than the reference bridge arm among the second bridge arm, the third bridge arm, the fourth bridge arm and the fifth bridge arm; the phase shift angle of the target bridge arm relative to the reference bridge arm is used to control the timing of the drive signal of the target bridge arm, the first sampling current is the sampling current of the first end of the filtering module, the second sampling current is the sampling current between the second end of the fifth bridge arm and the second DC end, the first sampling voltage is the sampling voltage between the first AC end and the second AC end or the sampling voltage between the first end of the third bridge arm and the second end of the third bridge arm, and the second sampling voltage is the sampling voltage between the first DC end and the second DC end.

[0008] Optionally, the resonance module includes: a resonant inductor, a first resonant capacitor, a second resonant capacitor and a transformer;

[0009] The resonant inductor and the first resonant capacitor are connected in series with the primary winding of the transformer, and the second resonant capacitor is connected in series with the secondary winding of the transformer.

[0010] Optionally, the filtering module includes a first inductor and a second inductor, the first end of the first inductor is connected to the first end of the second inductor and the first AC end, the second end of the first inductor is connected to the midpoint of the third bridge arm, and the second end of the second inductor is connected to the midpoint of the second bridge arm.

[0011] Optionally, the filtering module includes a coupled inductor, a first end of the coupled inductor connected to the second end of the coupled inductor and the first AC end, a third end of the coupled inductor connected to the midpoint of the third bridge arm, and a fourth end of the coupled inductor connected to the midpoint of the second bridge arm.

[0012] Optionally, the energy conversion device also includes a first filter capacitor, a second filter capacitor and a third filter capacitor, wherein the two ends of the first filter capacitor are respectively connected to the first AC end and the second AC end, the two ends of the second filter capacitor are respectively connected to the first end of the third bridge arm and the second end of the third bridge arm, and the two ends of the third filter capacitor are respectively connected to the first end of the fifth bridge arm and the second end of the fifth bridge arm.

[0013] Optionally, the control module determines the phase shift angle of the target bridge arm relative to the reference bridge arm according to the required gain of the energy conversion device, the first sampled current, the second sampled current, the first sampled voltage, and the second sampled voltage, including:

[0014] The control module determines a phase shift angle between a first voltage waveform and a second voltage waveform according to a first sampling current, a second sampling current, a first sampling voltage, and a second sampling voltage, wherein the first voltage waveform is a voltage waveform between a bridge arm midpoint of the third bridge arm and a bridge arm midpoint of the second bridge arm, and the second voltage waveform is a voltage waveform between a bridge arm midpoint of the fourth bridge arm and a bridge arm midpoint of the fifth bridge arm;

[0015] The control module determines the phase shift angle of the target bridge arm relative to the reference bridge arm according to the phase shift angle between the first voltage waveform and the second voltage waveform, the required gain of the energy conversion device, the turns ratio of the transformer, the first sampled voltage, and the second sampled voltage.

[0016] Optionally, the control module includes: a phase-locked loop, a first current control loop, a second current control loop, a voltage control loop, a multiplier, a minimization module and a phase shift modulation module;

[0017] The phase-locked loop is used to perform loop calculation on the first sampled voltage and output a first loop calculation result;

[0018] The second current control loop is used to perform loop calculation on a result of subtracting the second sampling current from the first reference current, and output a second loop calculation result;

[0019] The voltage control loop is used to perform loop calculation on the result of subtracting the second sampling voltage from the second reference voltage, and output a third loop calculation result;

[0020] The minimum value module is used to obtain the minimum value between the second loop calculation result and the third loop calculation result;

[0021] The multiplier is used to multiply the minimum value of the second loop calculation result and the third loop calculation result by the first loop calculation result to obtain a second reference current;

[0022] The first current control loop is used to perform loop calculation on the result of subtracting the second reference current from the first sampling current, and output a phase shift angle between the first voltage waveform and the second voltage waveform;

[0023] The phase shift modulation module is used to determine the phase shift angle of the target bridge arm relative to the reference bridge arm according to the phase shift angle between the first voltage waveform and the second voltage waveform, the required gain of the energy conversion device, the turns ratio of the transformer, the first sampled voltage, and the second sampled voltage.

[0024] Optionally, when the reference bridge arm is the third bridge arm and the target bridge arm includes the second bridge arm, the fourth bridge arm and the fifth bridge arm, the phase shift angle of the second bridge arm relative to the third bridge arm, the phase shift angle of the fourth bridge arm relative to the third bridge arm, and the phase shift angle of the fifth bridge arm relative to the third bridge arm are determined according to the following formula:

[0025] When the demand gain of the energy conversion device is less than 1,

[0026] D p =(1-D y1 );

[0027] D s1 =(1-D y1 -D α1 );

[0028] D s2 =(1-D y1 -D α1 );

[0029] D α1 =(1-D y1 +2D Φ ) / 2;

[0030] If D Φ <D ΦB , then D y1 = k × (2D Φ +1) / (2-k);

[0031] If D Φ ≥D ΦB , then D y1 =[2×D Φ ×(1-k)+2k-1] / k;

[0032] D ΦB = (1-k) / 2, k = Ge;

[0033] Ge is the required gain of the energy conversion device, D Φ is the phase shift angle between the first voltage waveform and the second voltage waveform, D p is the phase shift angle of the second bridge arm relative to the third bridge arm, D s1 is the phase shift angle of the fourth bridge arm relative to the third bridge arm, D s2is the phase shift angle of the fifth bridge arm relative to the third bridge arm.

[0034] Optionally, when the demand gain of the energy conversion device is greater than or equal to 1,

[0035] D p =0;

[0036] D s1 =D α2 -(1-D y2 );

[0037] D s2 =D α2 ;

[0038] D α2 =(1-D y2 +2D Φ ) / 2;

[0039] If D Φ <D ΦB , then D y2 = k × (2D Φ +1) / (2-k);

[0040] If D Φ ≥D ΦB , then D y2 =[2×D Φ ×(1-k)+2k-1] / k;

[0041] D ΦB = (1-k) / 2, k = 1 / Ge;

[0042] Ge is the required gain of the energy conversion device, D Φ is the phase shift angle between the first voltage waveform and the second voltage waveform, D p is the phase shift angle of the second bridge arm relative to the third bridge arm, D s1 is the phase shift angle of the fourth bridge arm relative to the third bridge arm, D s2 is the phase shift angle of the fifth bridge arm relative to the third bridge arm.

[0043] A second aspect of an embodiment of the present application provides a vehicle, comprising an energy conversion device and a battery according to the first aspect of an embodiment of the present application, wherein the energy conversion device is used to convert alternating current into direct current to charge the battery.

[0044] The energy conversion device of the embodiment of the present application can use fewer bridge arms compared to the two-stage architecture using the PFC module and the DC / DC module, thereby reducing the volume and cost of the energy conversion device. The control module can determine the phase shift angle of the target bridge arm relative to the reference bridge arm according to the required gain, the first sampled current, the second sampled current, the first sampled voltage, and the second sampled voltage of the energy conversion device, and can realize the soft switching action of the switches in the primary bridge arm module and the secondary bridge arm module, which can reduce the switching loss, thereby improving the conversion efficiency of the energy conversion device. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0046] Figure 1 is a schematic structural diagram of an energy conversion device provided in an embodiment of the present application;

[0047] Figure 2 is a schematic structural diagram of another energy conversion device provided in an embodiment of the present application;

[0048] Figure 3 is a schematic diagram of a specific control structure of an energy conversion device provided in an embodiment of the present application;

[0049] Figure 4 is a schematic diagram of a specific control structure of another energy conversion device provided in an embodiment of the present application;

[0050] Figure 5 is a schematic diagram of a specific control structure of another energy conversion device provided in an embodiment of the present application;

[0051] Figure 6 is a schematic diagram of a specific control structure of another energy conversion device provided in an embodiment of the present application;

[0052] Figure 7 It is a flow chart of a control method based on an energy conversion device provided in an embodiment of the present application;

[0053] Figure 8 This is a V in one power frequency cycle provided by the embodiment of the present application. ac 、V Bus 、V AB 、V CD andi p Waveform diagram of ;

[0054] Figures 9 to 12 is a driving signal of each switch when Ge<1 provided in an embodiment of the present application, V AB 、V CD and p Waveform diagram of ;

[0055] Figures 13 to 15 is a driving signal of each switch when Ge>1 provided in an embodiment of the present application, V AB 、V CD and p Waveform diagram of ;

[0056] Fig.16 The embodiment of the present application provides a PFC module, a DC / DC module and an energy conversion device;

[0057] Fig.17 It is a structural schematic diagram of a vehicle provided in an embodiment of the present application. DETAILED DESCRIPTION

[0058] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this application.

[0059] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, products or devices.

[0060] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0061] See also Figure 1 , Figure 1 Schematic diagram of the structure of an energy conversion device provided in an embodiment of the present application. Figure 1As shown, the energy conversion device may include a filter module 10, a primary bridge arm module 20, a resonance module 30, a secondary bridge arm module 40 and a control module 50; the primary bridge arm module 20 includes: a first bridge arm, a second bridge arm and a third bridge arm, and the secondary bridge arm module 40 includes a fourth bridge arm and a fifth bridge arm; the frequency of the driving signal of the second bridge arm, the frequency of the driving signal of the third bridge arm, the frequency of the driving signal of the fourth bridge arm, and the frequency of the driving signal of the fifth bridge arm are all greater than the frequency of the driving signal of the first bridge arm;

[0062] The first end of the filter module 10 is connected to the first AC end, the second end of the filter module 10 is connected to the bridge arm midpoint of the third bridge arm and the first end of the resonance module 30, the third end of the filter module 10 is connected to the bridge arm midpoint of the second bridge arm and the second end of the resonance module 30, and the bridge arm midpoint of the first bridge arm is connected to the second AC end; the third end of the resonance module 30 is connected to the bridge arm midpoint of the fourth bridge arm, and the fourth end of the resonance module 30 is connected to the bridge arm midpoint of the fifth bridge arm; the first end of the first bridge arm is connected to the first end of the second bridge arm and the first end of the third bridge arm, the second end of the first bridge arm is connected to the second end of the second bridge arm and the second end of the third bridge arm, the first end of the fourth bridge arm is connected to the first end of the fifth bridge arm and the first DC end, and the second end of the fourth bridge arm is connected to the second end of the fifth bridge arm and the second DC end;

[0063] The control module 50 determines the phase shift angle of the target bridge arm relative to the reference bridge arm according to the required gain of the energy conversion device, the first sampled current, the second sampled current, the first sampled voltage, and the second sampled voltage, so as to realize the soft switching action of the switches in the primary bridge arm module 20 and the secondary bridge arm module 40;

[0064] The reference bridge arm is one of the second bridge arm, the third bridge arm, the fourth bridge arm and the fifth bridge arm, and the target bridge arm is the bridge arm other than the reference bridge arm among the second bridge arm, the third bridge arm, the fourth bridge arm and the fifth bridge arm; the phase shift angle of the target bridge arm relative to the reference bridge arm is used to control the timing of the drive signal of the target bridge arm, the first sampling current is the sampling current of the first end of the filtering module 10, the second sampling current is the sampling current between the second end of the fifth bridge arm and the second DC end, the first sampling voltage is the sampling voltage between the first AC end and the second AC end or the sampling voltage between the first end of the third bridge arm and the second end of the third bridge arm, and the second sampling voltage is the sampling voltage between the first DC end and the second DC end.

[0065] like Figure 1As shown, the first bridge arm includes a first switch S1 and a second switch S2, the first end of the first switch S1 is connected to the first end of the first bridge arm, the second end of the first switch S1 is connected to the first end of the second switch S2 and the bridge arm midpoint of the first bridge arm, and the second end of the second switch S2 is connected to the second end of the first bridge arm. The driving signal of the first bridge arm includes the first driving signal and the second driving signal. The control module 50 can control the driving module to send a first driving signal to the third end of the first switch S1, and the first driving signal is used to control the on or off of the first switch S1; the control module 50 can control the driving module to send a second driving signal to the third end of the second switch S2, and the second driving signal is used to control the on or off of the second switch S2. The frequency of the first driving signal is the same as the frequency of the second driving signal, and the first driving signal and the second driving signal are complementary signals, that is, in one cycle of the first driving signal, one of the first switch S1 and the second switch S2 is turned on and the other is turned off. Exemplarily, the duty cycle of the first driving signal and the second driving signal are both 50% (ignoring the dead time). Exemplarily, the frequency of the first driving signal and the frequency of the second driving signal are grid frequencies, which may also be referred to as power frequency. For example, the grid frequency may be 50 Hz.

[0066] like Figure 1 As shown, the second bridge arm includes a third switch S3 and a fourth switch S4, the first end of the third switch S3 is connected to the first end of the second bridge arm, the second end of the third switch S3 is connected to the first end of the fourth switch S4 and the bridge arm midpoint of the second bridge arm, and the second end of the fourth switch S4 is connected to the second end of the second bridge arm. The driving signal of the second bridge arm includes the third driving signal and the fourth driving signal. The control module 50 can control the driving module to send a third driving signal to the third end of the third switch S3, and the third driving signal is used to control the conduction or shutoff of the third switch S3; the control module 50 can control the driving module to send a fourth driving signal to the third end of the fourth switch S4, and the fourth driving signal is used to control the conduction or shutoff of the fourth switch S4. The frequency of the third driving signal is the same as the frequency of the fourth driving signal, and the third driving signal and the fourth driving signal are complementary signals, that is, in one cycle of the third driving signal, one of the third switch S3 and the fourth switch S4 is turned on and the other is turned off. Exemplarily, the duty cycle of the third driving signal and the fourth driving signal is 50% (ignoring the dead time). The frequency of the third driving signal and the frequency of the fourth driving signal are switching frequencies. For example, the switching frequency may be 50 kilohertz (KHz).

[0067] like Figure 1As shown, the third bridge arm includes a fifth switch S5 and a sixth switch S6, the first end of the fifth switch S5 is connected to the first end of the third bridge arm, the second end of the fifth switch S5 is connected to the first end of the sixth switch S6 and the bridge arm midpoint of the third bridge arm, and the second end of the sixth switch S6 is connected to the second end of the third bridge arm. The driving signal of the third bridge arm includes the fifth driving signal and the sixth driving signal. The control module 50 can control the driving module to send a fifth driving signal to the third end of the fifth switch S5, and the fifth driving signal is used to control the conduction or shutoff of the fifth switch S5; the control module 50 can control the driving module to send a sixth driving signal to the third end of the sixth switch S6, and the sixth driving signal is used to control the conduction or shutoff of the sixth switch S6. The frequency of the fifth driving signal is the same as the frequency of the sixth driving signal, and the fifth driving signal and the sixth driving signal are complementary signals, that is, in one cycle of the fifth driving signal, one of the fifth switch S5 and the sixth switch S6 is turned on and the other is turned off. Exemplarily, the duty cycle of the fifth driving signal and the sixth driving signal is 50% (ignoring the dead time). The frequency of the fifth driving signal and the frequency of the sixth driving signal are switching frequencies. For example, the switching frequency may be 50 KHz.

[0068] like Figure 1 As shown, the fourth bridge arm includes a seventh switch S7 and an eighth switch S8, the first end of the seventh switch S7 is connected to the first end of the fourth bridge arm, the second end of the seventh switch S7 is connected to the first end of the eighth switch S8 and the bridge arm midpoint of the fourth bridge arm, and the second end of the eighth switch S8 is connected to the second end of the fourth bridge arm. The driving signal of the fourth bridge arm includes the seventh driving signal and the eighth driving signal. The control module 50 can control the driving module to send the seventh driving signal to the third end of the seventh switch S7, and the seventh driving signal is used to control the conduction or shutoff of the seventh switch S7; the control module 50 can control the driving module to send the eighth driving signal to the third end of the eighth switch S8, and the eighth driving signal is used to control the conduction or shutoff of the eighth switch S8. The frequency of the seventh driving signal is the same as the frequency of the eighth driving signal, and the seventh driving signal and the eighth driving signal are complementary signals, that is, in one cycle of the seventh driving signal, one of the seventh switch S7 and the eighth switch S8 is turned on and the other is turned off. Exemplarily, the duty cycle of the seventh driving signal and the eighth driving signal is 50% (ignoring the dead time). The frequency of the seventh driving signal and the frequency of the eighth driving signal are switching frequencies. For example, the switching frequency may be 50 KHz.

[0069] like Figure 1As shown, the fifth bridge arm includes a ninth switch S9 and a tenth switch S10, the first end of the ninth switch S9 is connected to the first end of the fifth bridge arm, the second end of the ninth switch S9 is connected to the first end of the tenth switch S10 and the bridge arm midpoint of the fifth bridge arm, and the second end of the tenth switch S10 is connected to the second end of the fifth bridge arm. The driving signal of the fifth bridge arm includes the ninth driving signal and the tenth driving signal. The control module 50 can control the driving module to send a ninth driving signal to the third end of the ninth switch S9, and the ninth driving signal is used to control the on or off of the ninth switch S9; the control module 50 can control the driving module to send a tenth driving signal to the third end of the tenth switch S10, and the tenth driving signal is used to control the on or off of the tenth switch S10. The frequency of the ninth driving signal is the same as the frequency of the tenth driving signal, and the ninth driving signal and the tenth driving signal are complementary signals, that is, in one cycle of the ninth driving signal, one of the ninth switch S9 and the tenth switch S10 is turned on and the other is turned off. Exemplarily, the duty cycle of the ninth drive signal and the tenth drive signal are both 50% (ignoring the dead time). The frequency of the ninth drive signal and the frequency of the tenth drive signal are switching frequencies. For example, the switching frequency may be 50 KHz.

[0070] like Figure 1 As shown, the switches in the primary bridge arm module 20 include: a first switch S1, a second switch S2, a third switch S3, a fourth switch S4, a fifth switch S5 and a sixth switch S6. The switches in the secondary bridge arm module 40 include a seventh switch S7, an eighth switch S8, a ninth switch S9 and a tenth switch S10.

[0071] Among them, the first switch S1, the second switch S2, the third switch S3, the fourth switch S4, the fifth switch S5, the sixth switch S6, the seventh switch S7, the eighth switch S8, the ninth switch S9 and the tenth switch S10 can be metal-oxide-semiconductor field-effect transistors (Metal-Oxide-Semiconductor Field-Effect Transistor, MOSFET) or insulated-gate bipolar transistors (Insulate-Gate Bipolar Transistor, IGBT). MOSFET can also be called MOS tube or MOS transistor. Figure 1 The switches in the examples are all N-type MOS transistors, which can be referred to as NMOS transistors. MOSFETs can be silicon carbide (SiC) MOSFETs or gallium nitride (GaN) MOSFETs. Silicon carbide MOSFETs are MOSFETs made of silicon carbide materials, and gallium nitride MOSFETs are MOSFETs made of gallium nitride materials.

[0072] The phase shift angle of the target bridge arm relative to the reference bridge arm refers to the phase difference between the starting position of the drive signal of the target bridge arm in one cycle and the starting position of the drive signal of the reference bridge arm in one cycle.

[0073] Soft switching action is to introduce resonance before and after the switch is turned off and on, so that the switch can achieve zero voltage switching (that is, the voltage across the switch drops to zero before the switch is turned on); or to achieve zero current switching (that is, the current of the switch drops to zero before the switch is turned off), thereby eliminating the overlap of voltage and current in the process of turning off and on, reducing the rate of change of voltage and current, significantly reducing or even eliminating switching losses, and significantly reducing switching noise.

[0074] In a possible embodiment, the energy conversion device can realize the function of converting AC to DC (Alternating Current / Direct Current, AC / DC). In this case, the first AC terminal and the second AC terminal serve as AC input terminals, and the first DC terminal and the second DC terminal serve as DC output terminals. The energy conversion device can convert the input AC into DC output.

[0075] In a possible embodiment, the energy conversion device can realize the function of converting direct current into alternating current (DC / AC). In this case, the first AC terminal and the second AC terminal serve as AC output terminals, and the first DC terminal and the second DC terminal serve as DC input terminals. The energy conversion device can convert the input DC into AC output.

[0076] Exemplarily, the energy conversion device may be an onboard charger on a vehicle. The onboard charger may be a bidirectional onboard charger that can support converting AC into DC and converting DC into AC.

[0077] The energy conversion device of the embodiment of the present application can use fewer bridge arms compared to the two-stage architecture using the PFC module and the DC / DC module, and does not need to use electrolytic capacitors, thereby reducing the volume and cost of the energy conversion device. The control module 50 can determine the phase shift angle of the target bridge arm relative to the reference bridge arm according to the required gain, the first sampled current, the second sampled current, the first sampled voltage, and the second sampled voltage of the energy conversion device, and can realize the soft switching action of the switches in the primary bridge arm module 20 and the secondary bridge arm module 40, which can reduce the switching loss, thereby improving the conversion efficiency of the energy conversion device.

[0078] Optionally, the resonance module 30 includes: a resonance inductor L r , the first resonant capacitor C rp , the second resonant capacitor C rsand transformer Tr. The resonant inductor L r and the first resonant capacitor C rp are respectively connected in series with the primary winding of the transformer Tr, and the second resonant capacitor C rs It is connected in series with the secondary winding of the transformer Tr.

[0079] The first end of the primary winding of the transformer Tr and the excitation inductance L m The first end of the primary winding of the transformer Tr is connected to the excitation inductor L m The second end.

[0080] The primary winding of the transformer Tr may be integrated with an excitation inductor, or the excitation inductor may be independent of the primary winding of the transformer. Figure 1 The explanation is based on the assumption that the magnetizing inductance is independent of the primary winding of the transformer.

[0081] like Figure 1 As shown, the resonant inductor L r The first end of the resonant inductor L is connected to the bridge arm midpoint of the third bridge arm. r The second end of the transformer Tr is connected to the first end of the primary winding of the transformer Tr and the excitation inductor L m The first end of the primary winding of the transformer Tr is connected to the excitation inductor L m The second end and the first resonant capacitor C rp The first end of the first resonant capacitor C rp The second end of the secondary winding of the transformer Tr is connected to the midpoint of the bridge arm of the second bridge arm; the first end of the secondary winding of the transformer Tr is connected to the midpoint of the bridge arm of the fourth bridge arm, and the second end of the secondary winding of the transformer Tr is connected to the second resonant capacitor C rs The first end of the second resonant capacitor C rs The second end of is connected to the bridge arm midpoint of the fifth bridge arm.

[0082] It should be noted that Figure 1 The connection mode in the resonance module 30 is a possible connection mode. r , the first resonant capacitor C rp It can be connected in series with the primary winding of the transformer Tr (for example, the resonant inductor L r With the first resonant capacitor C rp After being connected in series, it is connected between the midpoint of the third bridge arm and the first end of the primary winding of the transformer Tr; for another example, the resonant inductor L r With the first resonant capacitor C rp After being connected in series, it is connected between the middle point of the second bridge arm and the second end of the primary winding of the transformer Tr; for another example, the resonant inductor L rThe first resonant capacitor C is connected in series between the middle point of the third bridge arm and the first end of the primary winding of the transformer Tr. rp is connected in series between the middle point of the second bridge arm and the second end of the primary winding of the transformer Tr; for example, the first resonant capacitor C rp Connected in series between the midpoint of the third bridge arm and the first end of the primary winding of the transformer Tr, the resonant inductor L r is connected in series between the middle point of the second bridge arm and the second end of the primary winding of the transformer Tr), the second resonant capacitor C rs It can be connected in series with the secondary winding of the transformer Tr at will, and the embodiment of the present application does not limit it (for example, the second resonant capacitor C rs is connected in series between the first end of the secondary winding of the transformer Tr and the middle point of the fourth bridge arm; for example, the second resonant capacitor C rs connected in series between the second end of the secondary winding of the transformer Tr and the midpoint of the bridge arm of the fifth bridge arm).

[0083] The frequencies of the second bridge arm, the third bridge arm, the fourth bridge arm and the fifth bridge arm are switching frequencies, and the switching frequencies are greater than the resonance frequency of the resonance module 30 .

[0084] Optional, such as Figure 1 As shown, the filtering module 10 includes a first inductor L1 and a second inductor L2, the first end of the first inductor L1 is connected to the first end of the second inductor L2 and the first AC end, the second end of the first inductor L1 is connected to the midpoint of the third bridge arm, and the second end of the second inductor L2 is connected to the midpoint of the second bridge arm.

[0085] The first inductor L1 and the second inductor L2 are AC side inductors, providing filtering and energy storage functions.

[0086] Optional, such as Figure 2 As shown, the filtering module 10 includes a coupled inductor, a first end of the coupled inductor is connected to the second end of the coupled inductor and the first AC end, a third end of the coupled inductor is connected to the midpoint of the third bridge arm, and a fourth end of the coupled inductor is connected to the midpoint of the second bridge arm.

[0087] In the embodiment of the present application, a coupled inductor is used to Figure 1 The first inductor L1 and the second inductor L2 are integrated into one inductor L, which reduces the volume of the filter module 10 and further reduces the volume of the energy conversion device, thereby reducing the cost and improving the power density of the energy conversion device.

[0088] Optional, such as Figure 1 or Figure 2As shown, the energy conversion device also includes a first filter capacitor C1, a second filter capacitor C2 and a third filter capacitor C3, the two ends of the first filter capacitor C1 are respectively connected to the first AC end and the second AC end, the two ends of the second filter capacitor C2 are respectively connected to the first end of the third bridge arm and the second end of the third bridge arm, and the two ends of the third filter capacitor C3 are respectively connected to the first end of the fifth bridge arm and the second end of the fifth bridge arm.

[0089] The first filter capacitor C1 is an AC side filter capacitor, the second filter capacitor C2 is a primary side high-frequency filter capacitor, used to absorb the high-frequency ripple of the switch, and the third filter capacitor C3 is a DC side high-frequency filter capacitor, used to absorb the high-frequency ripple.

[0090] Optionally, the control module 50 determines the phase shift angle of the target bridge arm relative to the reference bridge arm according to the required gain of the energy conversion device, the first sampled current, the second sampled current, the first sampled voltage, and the second sampled voltage, including:

[0091] The control module 50 determines a phase shift angle between a first voltage waveform and a second voltage waveform according to a first sampling current, a second sampling current, a first sampling voltage, and a second sampling voltage, wherein the first voltage waveform is a voltage waveform between a bridge arm midpoint of the third bridge arm and a bridge arm midpoint of the second bridge arm, and the second voltage waveform is a voltage waveform between a bridge arm midpoint of the fourth bridge arm and a bridge arm midpoint of the fifth bridge arm;

[0092] The control module 50 determines the phase shift angle of the target bridge arm relative to the reference bridge arm according to the phase shift angle between the first voltage waveform and the second voltage waveform, the required gain of the energy conversion device, the turns ratio of the transformer Tr, the first sampled voltage, and the second sampled voltage.

[0093] like Figure 1 or Figure 2 As shown, the voltage at the bridge arm midpoint B of the second bridge arm and the bridge arm midpoint A of the third bridge arm is V AB The voltage at the middle point C of the fourth bridge arm and the middle point D of the fifth bridge arm is V CD Among them, the first voltage waveform is V AB The second voltage waveform is V CD waveform.

[0094] The phase shift angle between the first voltage waveform and the second voltage waveform refers to the phase shift angle of the second voltage waveform relative to the first voltage waveform, that is, V CD Relative to V AB The phase difference between the high level center lines in one cycle. For example, Figures 10 to 15 As shown, the first voltage waveform V AB and the second voltage waveform VCD The phase shift angle between Φ , V CD Relative to V AB In one cycle (T s ) is D Φ ×T s / 2.

[0095] See also Figure 3 , Figure 3 It is a schematic diagram of a specific control structure of an energy conversion device provided in an embodiment of the present application. Figure 3 is Figure 1 Based on Figure 3 As shown, in Figure 1 On the basis of, the control module 50 includes: a phase-locked loop, a first current control loop, a second current control loop, a voltage control loop, a multiplier, a minimization module and a phase shift modulation module. Figure 3 The energy conversion device is used to convert the input AC into DC output.

[0096] The phase-locked loop is used to Figure 3 The V ac_FB ) performs loop calculation and outputs the first loop calculation result. The first sampling voltage V ac_FB is the sampling voltage between the first AC terminal and the second AC terminal. The first sampling voltage V ac_FB is through Figure 3 The AC voltage sampling module is used to sample the voltage between the first AC terminal and the second AC terminal.

[0097] The second current control loop is used to control the second sampling current (such as Figure 3 I HV_FB ) and the first reference current (such as Figure 3 I HV_Ref ) performs loop calculation on the result after subtraction operation, and outputs the second loop calculation result. Among them, the first reference current I HV_Ref is the output demand current currently set by the energy conversion device, and the second sampling current I HV_FB is through Figure 3 The output current sampling module is used to sample the current between the second end of the fifth bridge arm and the second DC end. The current between the second end of the fifth bridge arm and the second DC end can be a filtered current (for example, Figure 3 The third filter capacitor C3 in the filter is the filtered current).

[0098] The voltage control loop is used to control the second sampled voltage (such as Figure 3 The VHV_FB ) and a second reference voltage (such as Figure 3 The V HV_Ref ) performs loop calculation on the result after subtraction operation, and outputs the third loop calculation result. Among them, the second reference voltage V HV_Ref is the output voltage currently set by the energy conversion device, and the second sampling voltage V HV_FB is through Figure 3 The output voltage sampling module is used to sample the voltage between the first DC terminal and the second DC terminal.

[0099] The minimum value module is used to obtain the minimum value between the second loop calculation result and the third loop calculation result.

[0100] The multiplier is used to multiply the minimum value of the second loop calculation result and the third loop calculation result by the first loop calculation result to obtain a second reference current (such as Figure 3 The i shown ac_Ref ).

[0101] The first current control loop is used to control the second reference current i ac_Ref and the first sampling current (such as Figure 3 Shown I ac_FB ) after subtraction (i.e. ac_Ref -I ac_FB ) performs loop calculation and outputs the phase shift angle between the first voltage waveform and the second voltage waveform (such as Figure 3 D Φ ). ac_FB is through Figure 3 The AC current module is used to sample the sampling current of the first end of the filter module.

[0102] See also Figure 4 , Figure 4 Schematic diagram of a specific control structure of another energy conversion device provided in an embodiment of the present application. Figure 4 As shown, the first sampling current may be a sampling current on the first inductor L1 (eg Figure 4 I L1_FB ) and the sampling current on the second inductor L2 (such as Figure 4 I L2_FB ). L1_FB is through Figure 4 The AC current module 1 samples the current, I L2_FB is through Figure 4The AC current module 2 is used to sample the current flowing through the first inductor L1, and the AC current module 2 is used to sample the current flowing through the second inductor L2.

[0103] Figure 3 and Figure 4 In the embodiment, the first sampling voltage is a sampling voltage between the first AC terminal and the second AC terminal.

[0104] Figure 5 and Figure 6 In, with Figure 3 and Figure 4 By comparison, the first sampling voltage is the sampling voltage between the first end of the third bridge arm and the second end of the third bridge arm, that is, the voltage across the second filter capacitor C2. Figure 5 and Figure 6 As shown, the Bus voltage sampling module is used to sample the voltage V across the second filter capacitor C2. Bus_FB The resonant current sampling module is used to sample the resonant inductance L r The current i p .

[0105] The phase shift modulation module is used to adjust the phase shift angle D between the first voltage waveform and the second voltage waveform according to the phase shift angle D between the first voltage waveform and the second voltage waveform. Φ , the required gain Ge of the energy conversion device, the turns ratio n of the transformer Tr, the first sampling voltage (such as Figure 3 or Figure 4 The V ac_FB , or Figure 5 or Figure 6 The V Bus_FB )、The second sampling voltage V HV_FB Determine the phase shift angle of the target bridge arm relative to the reference bridge arm.

[0106] Figure 3 In the embodiment, the PWM wave generation module is a pulse width modulation (PWM) module, which can generate a wave generation signal for each switch according to the phase shift angle of the target bridge arm relative to the reference bridge arm; the drive module amplifies and isolates the wave generation signal of each switch to generate a drive signal for each switch, and the drive signal of the switch is used to drive the switch to be turned on or off.

[0107] exist Figure 3 When realizing the AC / DC function, Figure 3 V ac It is the AC input power supply of the power grid, the first filter capacitor C1 is the AC input filter capacitor; the first inductor L1 and the second inductor L2 are AC input inductors, which provide filtering and energy storage functions. Figure 3The first switch S1 and the second switch S2 work according to the grid frequency (for example, 50Hz), and the first bridge arm composed of the first switch S1 and the second switch S2 is called the slow bridge arm; the third switch S3 and the fourth switch S4 form the second bridge arm, and the fifth switch S5 and the sixth switch S6 form the third bridge arm. The second bridge arm and the third bridge arm are called fast bridge arms, and work according to the switching frequency. The voltage between the bridge arm midpoint A of the third bridge arm and the bridge arm midpoint B of the second bridge arm is called V AB The second filter capacitor C2 is a high-frequency filter capacitor on the primary side, used to absorb the high-frequency ripple of the switch. r With the first resonant capacitor C rp And the second resonant capacitor C rs To form a resonant circuit, the excitation inductance L m is the excitation inductance of the transformer Tr, n:1 is the electrical insulation and voltage ratio conversion of the primary and secondary sides provided by the transformer Tr; the seventh switch S7 and the eighth switch S8 form a fourth bridge arm, the ninth switch S9 and the tenth switch S10 form a fifth bridge arm, the fourth bridge arm and the fifth bridge arm are also called fast bridge arms, and they also work according to the switching frequency. The voltage between the bridge arm midpoint C of the fourth bridge arm and the bridge arm midpoint D of the fifth bridge arm is V CD The third filter capacitor C3 is an output high-frequency filter capacitor, which is used to absorb high-frequency ripples.

[0108] Figure 3 In the energy conversion device, the control module 50 can adopt dual-loop control. To meet the charging requirements of the energy conversion device for constant voltage and constant current, the second current control loop and the voltage control loop in the control module 50 are competitively controlled, and the minimum value of the outputs of the two is used to determine the reference current of the first current control loop (that is, the second reference current i ac_Ref ). The first current control loop is used to control the first sampling current I ac_FB and the first sampling voltage V ac_FB The output of the first current control loop is used to determine the midpoint voltage V of the primary bridge arm (the primary bridge arm includes the second bridge arm and the third bridge arm) and the secondary bridge arm (the secondary bridge arm includes the fourth bridge arm and the fifth bridge arm). AB and V CD The phase shift angle D Φ For the convenience of control, the third bridge arm (fifth switch S5 and sixth switch S6) is used as a reference. If the phase shift angle (or phase shift time) of the second bridge arm (third switch S3 and fourth switch S4) relative to the third bridge arm is defined as D p , the phase shift angle (or phase shift time) of the fourth bridge arm (the seventh switch S7 and the eighth switch S8) relative to the third bridge arm is D S1 , the phase shift angle (or phase shift time) of the fifth bridge arm (ninth switch S9 and tenth switch S10) relative to the third bridge arm is DS2 Finally, the phase shift modulation module outputs D according to the first current control Φ , the first sampling voltage V ac_FB , the second sampling voltage V HV_FB and the turns ratio n of the transformer Tr to determine D p , D s1 and D s2 The value of , then the PWM wave generating module of the control module 50 generates a wave generating signal, and the driving module generates a driving signal of each switch, so as to control the third switch S3, the fourth switch S4, the fifth switch S5, the sixth switch S6, the seventh switch S7, the eighth switch S8, the ninth switch S9 and the tenth switch S10.

[0109] based on Figure 3 or Figure 4 or Figure 5 or Figure 6 The energy conversion device shown in the embodiment of the present application provides a control method based on the energy conversion device. Figure 7 , Figure 7 is a flow chart of a control method based on an energy conversion device provided in an embodiment of the present application. Figure 7 As shown, the control method based on the energy conversion device includes the following steps:

[0110] 701, the control module determines the phase shift angle between the first voltage waveform and the second voltage waveform according to the first sampling current, the second sampling current, the first sampling voltage, and the second sampling voltage, the first voltage waveform being the voltage waveform between the midpoint of the third bridge arm and the midpoint of the second bridge arm, and the second voltage waveform being the voltage waveform between the midpoint of the fourth bridge arm and the midpoint of the fifth bridge arm.

[0111] The first sampling current is the sampling current of the first end of the filter module 10, the second sampling current is the sampling current between the second end of the fifth bridge arm and the second DC end, and the first sampling voltage is the sampling voltage between the first AC end and the second AC end (such as Figure 3 and Figure 4 as shown) or the sampling voltage between the first end of the third bridge arm and the second end of the third bridge arm (as shown Figure 5 and Figure 6 As shown), the second sampling voltage is a sampling voltage between the first DC terminal and the second DC terminal.

[0112] Step 701 can be performed by Figure 3 or Figure 4 or Figure 5 or Figure 6 The phase-locked loop, the first current control loop, the second current control loop, the voltage control loop, the multiplier, and the small module in the control module of the energy conversion device shown are executed.

[0113] Specifically, Figures 3 to 6 In the process, the AC voltage sampling module samples the voltage between the first AC terminal and the second AC terminal to obtain a first sampling voltage V ac_FB The phase-locked loop (PLL) processes the first sampling voltage V ac_FB The output current sampling module samples the current between the second end of the fifth bridge arm and the second DC end to obtain a second sampling current I HV_FB The second current control loop controls the second sampling current I HV_FB and the first reference current I HV_Ref The result after the subtraction operation is loop-calculated, and the second loop calculation result is output. Among them, the first reference current I HV_Ref is the output demand current currently set by the energy conversion device. The output voltage sampling module samples the voltage between the first DC terminal and the second DC terminal. The voltage control loop controls the second sampling voltage V HV_FB and the second reference voltage V HV_Ref The result after the subtraction operation is loop-calculated, and the third loop calculation result is output. Among them, the second reference voltage V HV_Ref is the output required voltage currently set by the energy conversion device. The small module takes the minimum value of the second loop calculation result and the third loop calculation result. The multiplier multiplies the minimum value of the second loop calculation result and the third loop calculation result by the first loop calculation result to obtain the second reference current i ac_Ref . Figure 3 or Figure 5 The first current control loop in the second reference current i ac_Ref and the first sampling current I ac_FB The result after subtraction (i.e. ac_Ref -I ac_FB ) performs loop calculation and outputs the first voltage waveform V AB and the second voltage waveform V CD The phase shift angle D Φ .in, Figure 3 or Figure 5 The AC current module in the filter module samples the current at the first end, that is, the first sampling current I ac_FB .

[0114] Figure 4 or Figure 6 The first current control loop in the second reference current i ac_Ref and the first sampling current I ac_FB The result after subtraction (i.e. ac_Ref -I ac_FB ) performs loop calculation and outputs the first voltage waveform V ABand the second voltage waveform V CD The phase shift angle D Φ .in, Figure 4 or Figure 6 The AC current module in the sample flows through the first inductor L1 and obtains the current of the first inductor L2. L1_FB . Figure 4 or Figure 6 The AC current module 2 in the embodiment is used to sample the current flowing through the second inductor L2 to obtain I L2_FB The first sampling current is I L1_FB and I L2_FB The sum of the first sampling current I ac_FB =I L1_FB +I L2_FB .

[0115] 702, the control module determines the phase shift angle of the target bridge arm relative to the reference bridge arm according to the phase shift angle between the first voltage waveform and the second voltage waveform, the required gain of the energy conversion device, the turns ratio of the transformer, the first sampled voltage, and the second sampled voltage.

[0116] The required gain of the energy conversion device is defined as: Ge = n × V CD / V AB , n is the turns ratio of the transformer Tr (i.e., the turns ratio of the primary winding to the secondary winding of the transformer Tr). V AB is the first voltage waveform, V CD is the second voltage waveform.

[0117] Step 702 can be performed by a phase shift modulation module in the control module. The control strategy of the phase shift modulation module is as follows: Figure 8 As shown, the first voltage waveform V is first output by the first current control loop. AB and the second voltage waveform V CD The phase shift angle D Φ Next, calculate the variables needed in the phase shift algorithm, where the k value is an intermediate variable and k is determined by Ge. ΦB D Φ After the relevant variables are calculated, the equivalent duty cycle D of the primary bridge arm is calculated according to whether Ge is greater than 1. y1 And the equivalent duty cycle of the secondary bridge arm D y2 , and finally determine the phase shift angles of the other three bridge arms relative to the reference bridge arm: D p , D s1 and D s2 .

[0118] Exemplarily, when the reference bridge arm is the third bridge arm, and the target bridge arm includes the second bridge arm, the fourth bridge arm, and the fifth bridge arm, the phase shift angle of the second bridge arm relative to the third bridge arm, the phase shift angle of the fourth bridge arm relative to the third bridge arm, and the phase shift angle of the fifth bridge arm relative to the third bridge arm are determined according to the following formula:

[0119] When the demand gain of the energy conversion device is less than 1,

[0120] D p =(1-D y1 );

[0121] D s1 =(1-D y1 -D α1 );

[0122] D s2 =(1-D y1 -D α1 );

[0123] D α1 =(1-D y1 +2D Φ ) / 2;

[0124] If D Φ <D ΦB , then D y1 = k × (2D Φ +1) / (2-k);

[0125] If D Φ ≥D ΦB , then D y1 =[2×D Φ ×(1-k)+2k-1] / k;

[0126] D ΦB = (1-k) / 2, k = Ge;

[0127] When the demand gain of the energy conversion device is greater than or equal to 1,

[0128] D p =0;

[0129] D s1 =D α2 -(1-D y2 );

[0130] D s2 =D α2 ;

[0131] D α2 =(1-D y2+2D Φ ) / 2;

[0132] If D Φ <D ΦB , then D y2 = k × (2D Φ +1) / (2-k);

[0133] If D Φ ≥D ΦB , then D y2 =[2×D Φ ×(1-k)+2k-1] / k;

[0134] D ΦB = (1-k) / 2, k = 1 / Ge;

[0135] Where Ge is the required gain of the energy conversion device, D Φ is the phase shift angle between the first voltage waveform and the second voltage waveform, D p is the phase shift angle of the second bridge arm relative to the third bridge arm, D s1 is the phase shift angle of the fourth bridge arm relative to the third bridge arm, D s2 is the phase shift angle of the fifth bridge arm relative to the third bridge arm.

[0136] In order to explain the control strategy and control effect of the embodiment of the present application in more detail, Fig. 9 Given a power frequency cycle (such as Fig. 9 T line ) Input AC voltage V ac , the voltage V of the second filter capacitor C2 Bus , the first voltage waveform V AB , the second voltage waveform V CD And the primary current waveform of transformer Tr p . V ac for Figure 3 or Figure 4 or Figure 5 or Figure 6 The voltage between the first AC terminal and the second AC terminal, i p for Figure 3 or Figure 4 or Figure 5 or Figure 6 Medium resonant inductor L r The current from Fig. 9 It can be seen that the control strategy of the embodiment of the present application can well realize the power factor value and power transmission control. It should be noted that the power frequency period T line greater than the switching period T s .

[0137] Figure 10~Figure 15 The typical timing waveforms of the switches of six different modulation methods are given based on the control strategy of the embodiment of the present application to distinguish Ge<1 (i.e., the energy conversion device works in the buck mode) and Ge>1 (i.e., the energy conversion device works in the boost mode). By using the control strategy, soft switching actions under different output voltages and different loads can be achieved, thereby improving the efficiency of the energy conversion device. Figure 10~Figure 15 In the figure, the horizontal axis is time, and the vertical axis is the amplitude of the waveform, wherein the waveform of the drive signal of the switch is in the time period when the vertical axis is 0, the switch is turned off; the waveform of the drive signal of the switch is in the time period when the vertical axis is greater than 0, the switch is turned on (for example, when the waveform of the drive signal of the fifth switch S5 is 0 when the vertical axis is 0, it means that the fifth switch S5 is turned off, and when the waveform of the drive signal of the fifth switch S5 is greater than 0 when the vertical axis is greater than 0, it means that the fifth switch S5 is turned on). Ge is the required gain of the energy conversion device, D Φ is the phase shift angle between the first voltage waveform and the second voltage waveform, D p is the phase shift angle of the second bridge arm relative to the third bridge arm, D s1 is the phase shift angle of the fourth bridge arm relative to the third bridge arm, D s2 V is the phase shift angle of the fifth bridge arm relative to the third bridge arm. AB is the first voltage waveform, V CD is the second voltage waveform. p for Figure 3 or Figure 4 or Figure 5 or Figure 6 Medium resonant inductor L r The current on T s is the switching period. V ac for Figure 3 or Figure 4 or Figure 5 or Figure 6 The voltage value between the first AC terminal and the second AC terminal, V HV for Figure 3 The voltage value between the first DC terminal and the second DC terminal.

[0138] Figure 10~Figure 12 These are three typical control waveforms when Ge<1. For convenience, the dead time is ignored. The dotted line in the figure is the switching action moment. Taking the half switching cycle of the fifth switch S5 as an example, it can be seen that in the positive half cycle of the switching frequency of the fifth switch S5, i p When it is negative, the zero voltage switch (ZVS) corresponding to the primary switch is turned on, i p When i is positive, the ZVS of the corresponding secondary switch is turned on. Conversely, in the negative half cycle of the switching frequency, i p When it is negative, the ZVS of the corresponding secondary switch is turned on, ip When it is positive, the ZVS of the corresponding primary switch is turned on. Fig.10 Medium, Ge<1,D P =0,D S1 =D S2 >0. Fig.11 Medium, Ge<1, 0<D P <D S1 =D S2 . Fig.12 Medium, Ge<1, D P >D S1 =D S2 >0.

[0139] Figure 13~Figure 15 These are three typical control waveforms when Ge>1. For convenience, the dead time is ignored. The dotted line in the figure is the switching action moment. Taking the half switching cycle of the fifth switch S5 as an example, it can be seen that in the positive half cycle of the switching frequency of the fifth switch S5, i p When it is negative, the ZVS of the corresponding primary switch is turned on, i p When i is positive, the ZVS of the corresponding secondary switch is turned on. Conversely, in the negative half cycle of the switching frequency, i p When it is negative, the ZVS of the corresponding secondary switch is turned on, i p When it is positive, the ZVS of the corresponding primary switch is turned on. Fig.13 Medium, Ge>1, D P =0,D S1 =D S2 >0. Fig.14 Medium, Ge>1, D P =0,D S2 >D S1 >0. Fig.15 Medium, Ge>1,D P =0,D S1 <0, D S2 >0.

[0140] It should be noted that Figure 10~Figure 15 In, V AB and Figure 5 and Figure 6 V Bus_FB Same, V CD and Figure 3 , Figure 4 , Figure 5 and Figure 6 V HV_FB same.

[0141] Among them, the primary switch refers to the switch in the primary bridge arm module 20 (for example, the third switch S3, the fourth switch S4, the fifth switch S5 and the sixth switch S6), and the secondary switch refers to the switch in the secondary bridge arm module 40 (the seventh switch S7, the eighth switch S8, the ninth switch S9 and the tenth switch S10).

[0142] In the embodiment of the present application, in order to realize the power factor correction on the AC side, the control strategy of the dual active bridge (DAB) is combined in the modulation strategy, and the primary switch and the secondary switch of the transformer Tr are modulated according to a 50% duty cycle respectively, and the power factor correction and power transmission control are realized by the phase shift of the primary and secondary sides, which has the characteristics of simple control, easy implementation, and fast system response. In addition, in order to reduce switching losses and improve efficiency, the switching frequency f should be designed s Greater than the resonant frequency, at the same time, when Ge<1, the phase shift between the primary bridge arms can be increased, and when Ge>1, the phase shift between the secondary bridge arms can be increased, thereby further reducing the switching loss.

[0143] Figure 3 or Figure 4 or Figure 5 or Figure 6 The topological structure is simple, the cost is controllable, the life of the energy conversion device is extended, and the user's cost is saved. Figure 8 The control strategy is simple. Through the algorithm, the driver can flexibly configure the soft switching action of the switch under different output voltages and load conditions, thereby improving the energy conversion efficiency of the energy conversion device and improving the electromagnetic interference (EMI) characteristics of the energy conversion device.

[0144] See also Fig.16 , Fig.16 An energy conversion device using a PFC module and a DC / DC module is provided in an embodiment of the present application. Fig.16 For the traditional two-stage architecture topology, a large electrolytic capacitor (such as Fig.16 C shown bus ).and Fig.16 compared to, Figure 1 or Figure 2 For a single-stage topology, Figure 1 or Figure 2 The single-stage topology not only eliminates the need for electrolytic capacitors, but also reduces the total number of switches accordingly, which can further optimize the cost of the energy conversion device and improve the reliability of the energy conversion device.

[0145] See also Fig.17 , Fig.17 Schematic diagram of a vehicle structure provided by an embodiment of the present application. Fig.17 As shown, the vehicle may include an energy conversion device 100 and a battery 200. The battery 200 may be a power battery on the vehicle. The vehicle may be an electric vehicle. The energy conversion device 100 may be used to convert AC power into DC power to charge the battery 200. The battery 200 may input DC power into the energy conversion device 100, and the energy conversion device 100 converts the input DC power into an AC terminal to power an AC load.

[0146] Fig.17 The specific structure and working principle of the energy conversion device 100 can be found in the above Figures 1 to 6 The embodiments shown will not be described in detail here.

[0147] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0148] In the several embodiments provided in the present application, it should be understood that the disclosed energy conversion device and vehicle can be implemented in other ways. For example, the energy conversion device embodiments described above are only schematic, such as the division of the units, which is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed.

Claims

1. An energy conversion device, characterized in that: It includes a filtering module, a primary bridge arm module, a resonance module, a secondary bridge arm module and a control module; the primary bridge arm module includes: a first bridge arm, a second bridge arm and a third bridge arm, and the secondary bridge arm module includes a fourth bridge arm and a fifth bridge arm; the frequency of the driving signal of the second bridge arm, the frequency of the driving signal of the third bridge arm, the frequency of the driving signal of the fourth bridge arm, and the frequency of the driving signal of the fifth bridge arm are all greater than the frequency of the driving signal of the first bridge arm; the duty cycle of the driving signal of the first bridge arm, the duty cycle of the driving signal of the second bridge arm, the duty cycle of the driving signal of the third bridge arm, the duty cycle of the driving signal of the fourth bridge arm, and the duty cycle of the driving signal of the fifth bridge arm are all 50%; The first end of the filter module is connected to the first AC end, the second end of the filter module is connected to the bridge arm midpoint of the third bridge arm and the first end of the resonance module, the third end of the filter module is connected to the bridge arm midpoint of the second bridge arm and the second end of the resonance module, and the bridge arm midpoint of the first bridge arm is connected to the second AC end; the third end of the resonance module is connected to the bridge arm midpoint of the fourth bridge arm, and the fourth end of the resonance module is connected to the bridge arm midpoint of the fifth bridge arm; the first end of the first bridge arm is connected to the first end of the second bridge arm and the first end of the third bridge arm, the second end of the first bridge arm is connected to the second end of the second bridge arm and the second end of the third bridge arm, the first end of the fourth bridge arm is connected to the first end of the fifth bridge arm and the first DC end, and the second end of the fourth bridge arm is connected to the second end of the fifth bridge arm and the second DC end; The control module determines the phase shift angle of the target bridge arm relative to the reference bridge arm according to the required gain of the energy conversion device, the first sampled current, the second sampled current, the first sampled voltage, and the second sampled voltage, so as to realize the soft switching action of the switches in the primary bridge arm module and the secondary bridge arm module; The reference bridge arm is one of the second bridge arm, the third bridge arm, the fourth bridge arm and the fifth bridge arm, and the target bridge arm is the bridge arm other than the reference bridge arm among the second bridge arm, the third bridge arm, the fourth bridge arm and the fifth bridge arm; the phase shift angle of the target bridge arm relative to the reference bridge arm is used to control the timing of the drive signal of the target bridge arm, the first sampling current is the sampling current of the first end of the filtering module, the second sampling current is the sampling current between the second end of the fifth bridge arm and the second DC end, the first sampling voltage is the sampling voltage between the first AC end and the second AC end or the sampling voltage between the first end of the third bridge arm and the second end of the third bridge arm, and the second sampling voltage is the sampling voltage between the first DC end and the second DC end.

2. The energy conversion device according to claim 1, characterized in that: The resonance module includes: a resonant inductor, a first resonant capacitor, a second resonant capacitor and a transformer; The resonant inductor and the first resonant capacitor are respectively connected in series with the primary winding of the transformer, and the second resonant capacitor is connected in series with the secondary winding of the transformer.

3. The energy conversion device according to claim 1, characterized in that: The filtering module includes a first inductor and a second inductor, wherein the first end of the first inductor is connected to the first end of the second inductor and the first AC end, the second end of the first inductor is connected to the midpoint of the third bridge arm, and the second end of the second inductor is connected to the midpoint of the second bridge arm.

4. The energy conversion device according to claim 1, characterized in that: The filtering module includes a coupled inductor, a first end of the coupled inductor is connected to a second end of the coupled inductor and the first AC end, a third end of the coupled inductor is connected to a bridge arm midpoint of the third bridge arm, and a fourth end of the coupled inductor is connected to a bridge arm midpoint of the second bridge arm.

5. The energy conversion device according to any one of claims 1 to 4, characterized in that: The energy conversion device also includes a first filter capacitor, a second filter capacitor and a third filter capacitor, wherein two ends of the first filter capacitor are respectively connected to the first AC end and the second AC end, two ends of the second filter capacitor are respectively connected to the first end of the third bridge arm and the second end of the third bridge arm, and two ends of the third filter capacitor are respectively connected to the first end of the fifth bridge arm and the second end of the fifth bridge arm.

6. The energy conversion device according to claim 2, characterized in that: The control module determines the phase shift angle of the target bridge arm relative to the reference bridge arm according to the required gain of the energy conversion device, the first sampled current, the second sampled current, the first sampled voltage, and the second sampled voltage, including: The control module determines a phase shift angle between a first voltage waveform and a second voltage waveform according to a first sampling current, a second sampling current, a first sampling voltage, and a second sampling voltage, wherein the first voltage waveform is a voltage waveform between a bridge arm midpoint of the third bridge arm and a bridge arm midpoint of the second bridge arm, and the second voltage waveform is a voltage waveform between a bridge arm midpoint of the fourth bridge arm and a bridge arm midpoint of the fifth bridge arm; The control module determines the phase shift angle of the target bridge arm relative to the reference bridge arm according to the phase shift angle between the first voltage waveform and the second voltage waveform, the required gain of the energy conversion device, the turns ratio of the transformer, the first sampled voltage, and the second sampled voltage.

7. The energy conversion device according to claim 6, characterized in that: The control module includes: a phase-locked loop, a first current control loop, a second current control loop, a voltage control loop, a multiplier, a minimization module and a phase-shift modulation module; The phase-locked loop is used to perform loop calculation on the first sampled voltage and output a first loop calculation result; The second current control loop is used to perform loop calculation on a result of subtracting the second sampling current from the first reference current, and output a second loop calculation result; The voltage control loop is used to perform loop calculation on the result of subtracting the second sampling voltage from the second reference voltage, and output a third loop calculation result; The minimum value taking module is used to take the minimum value between the second loop calculation result and the third loop calculation result; The multiplier is used for multiplying the minimum value of the second loop calculation result and the third loop calculation result by the first loop calculation result to obtain a second reference current; The first current control loop is used to perform loop calculation on the result of subtracting the second reference current from the first sampling current, and output a phase shift angle between the first voltage waveform and the second voltage waveform; The phase shift modulation module is used to determine the phase shift angle of the target bridge arm relative to the reference bridge arm according to the phase shift angle between the first voltage waveform and the second voltage waveform, the required gain of the energy conversion device, the turns ratio of the transformer, the first sampled voltage, and the second sampled voltage.

8. The energy conversion device according to claim 6 or 7, characterized in that: In the case where the reference bridge arm is the third bridge arm, and the target bridge arm includes the second bridge arm, the fourth bridge arm, and the fifth bridge arm, the phase shift angle of the second bridge arm relative to the third bridge arm, the phase shift angle of the fourth bridge arm relative to the third bridge arm, and the phase shift angle of the fifth bridge arm relative to the third bridge arm are determined according to the following formula: When the demand gain of the energy conversion device is less than 1, D p =(1-D y1 ); D s1 =(1-D y1 -D α1 ); D s2 =(1-D y1 -D α1 ); D α1 =(1-D y1 +2D Φ ) / 2; If D Φ <D ΦB , then D y1 = k × (2 D Φ +1) / (2-k); If D Φ ≥D ΦB , then D y1 =[2×D Φ ×(1-k)+2k-1] / k; D ΦB =(1-k) / 2,k=Ge; Ge is the required gain of the energy conversion device, D Φ is the phase shift angle between the first voltage waveform and the second voltage waveform, D p is the phase shift angle of the second bridge arm relative to the third bridge arm, D s1 is the phase shift angle of the fourth bridge arm relative to the third bridge arm, D s2 is the phase shift angle of the fifth bridge arm relative to the third bridge arm.

9. The energy conversion device according to claim 8, characterized in that: When the demand gain of the energy conversion device is greater than or equal to 1, D p =0； D s1 =D α2 -(1-D y2 ); D s2 =D α2 ; D α2 =(1-D y2 +2D Φ ) / 2; If D Φ <D ΦB , then D y2 = k × (2D Φ +1) / (2-k); If D Φ ≥D ΦB , then D y2 =[2×D Φ ×(1-k)+2k-1] / k; D ΦB =(1-k) / 2,k=1 / Ge; Ge is the required gain of the energy conversion device, D Φ is the phase shift angle between the first voltage waveform and the second voltage waveform, D p is the phase shift angle of the second bridge arm relative to the third bridge arm, D s1 is the phase shift angle of the fourth bridge arm relative to the third bridge arm, D s2 is the phase shift angle of the fifth bridge arm relative to the third bridge arm.

10. A vehicle, characterized in that: It comprises an energy conversion device and a battery as described in any one of claims 1 to 9, wherein the energy conversion device is used to convert alternating current into direct current to charge the battery.

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