Energy conversion device and vehicle

Abstract

The embodiment of the present application provides an energy conversion device and a vehicle, the energy conversion device comprises a rectifying module, at least one direct current / direct current (DC / DC) module and a control module, a first end of the rectifying module is connected with a first alternating current end, a second end of the rectifying module is connected with a second alternating current end, a third end of the rectifying module is connected with a first end of the first DC / DC module, a fourth end of the rectifying module is connected with a second end of the first DC / DC module, a third end of the first DC / DC module is connected with a first direct current end, and a fourth end of the first DC / DC module is connected with a second direct current end; in the case that the energy conversion device works in a forward charging mode, the control module determines a duty cycle of a switch tube in the first DC / DC module according to a first sampling voltage and a first sampling current, so as to realize an alternating current / direct current function of the energy conversion device. 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 technical field of electronic circuits, in particular to an energy conversion device and a vehicle. BACKGROUND

[0002] With the development of electric vehicles, the on-board charger as an energy conversion device of the electric vehicle has been paid more and more attention. The energy conversion device can convert alternating current into direct current to charge the high-voltage battery in the electric vehicle. The energy conversion device usually adopts a two-stage architecture of a power factor correction (PFC) module and a direct current / direct current (DC / DC) module, which leads to an increase in the volume and cost of the energy conversion device and a low power density. SUMMARY

[0003] The energy conversion device and the vehicle provided by the embodiments of the present application can reduce the volume and cost of the energy conversion device.

[0004] The first aspect of the embodiments of the present application provides an energy conversion device, comprising a rectifier module, at least one direct current / direct current (DC / DC) module and a control module, a first end of the rectifier module is connected to a first alternating current end, a second end of the rectifier module is connected to a second alternating current end, a third end of the rectifier module is connected to a first end of a first DC / DC module, a fourth end of the rectifier module is connected to a second end of the first DC / DC module, a third end of the first DC / DC module is connected to a first direct current end, and a fourth end of the first DC / DC module is connected to a second direct current end; the first DC / DC module is any one of the at least one DC / DC module.

[0005] In a case where the energy conversion device works in a forward charging mode, the control module determines a duty cycle of a switch tube in the first DC / DC module according to a first sampling voltage and a first sampling current to realize an alternating current / direct current function of the energy conversion device; the first sampling voltage is a voltage between the first direct current end and the second direct current end, and the first sampling current is a current between the first direct current end and the second direct current end.

[0006] The energy conversion device of the embodiments of the present application adopts a single-stage topology, which can reduce the number of active devices compared with the two-stage architecture of the PFC module and the DC / DC module, thereby reducing the cost and volume of the energy conversion device. The control module can determine the duty cycle of the switch tube in the first DC / DC module according to the first sampling voltage and the first sampling current to realize the alternating current / direct current function of the energy conversion device, so that the energy conversion device works in the forward charging mode.

[0007] The energy conversion device can operate in a forward charging mode, and the forward charging mode can include any one of a continuous conduction mode (CCM), a discontinuous conduction mode (DCM), and a boundary conduction mode (BCM).

[0008] The at least one DC / DC module is connected in an interleaved and parallel manner, so as to improve the output power of the energy conversion device and be applicable to a high-power scene.

[0009] Optionally, the first DC / DC module includes a first capacitor, a second capacitor, a third capacitor, a first switch tube, a second switch tube, a first inductor, a second inductor, and a transformer. A first end of the first capacitor is connected to a first end of the first inductor and a third end of the rectifier module. A second end of the first inductor is connected to a first end of the second capacitor and a first end of the first switch tube. A second end of the second capacitor is connected to a first end of the second inductor and a first end of a primary winding of the transformer. A second end of the first capacitor is connected to a second end of the first switch tube, a second end of the second inductor, a second end of the primary winding, and a fourth end of the rectifier module. A first end of a secondary winding of the transformer is connected to a first end of the second switch tube. A second end of the second switch tube is connected to a first end of the third capacitor and the first DC terminal. A second end of the secondary winding is connected to a second end of the third capacitor and the second DC terminal.

[0010] In the embodiment, the first DC / DC module includes two switch tubes, i.e., a first switch tube and a second switch tube. A traditional single-stage AC / DC module includes at least two bridge arms (at least four switch tubes). Compared with the traditional single-stage AC / DC module, the first DC / DC module can reduce the number of switch tubes, so as to further reduce the cost and volume of the energy conversion device.

[0011] The transformer can be an isolation transformer, and can achieve isolation between the AC terminals (the first AC terminal and the second AC terminal) and the DC terminals (the first DC terminal and the second DC terminal).

[0012] Optionally, the rectifier module comprises a first rectifier tube, a second rectifier tube, a third rectifier tube and a fourth rectifier tube, a first end of the first rectifier tube is connected to a first end of the second rectifier tube and a first end of the first DC / DC module, a second end of the first rectifier tube is connected to a first end of the third rectifier tube and the first AC end, a second end of the second rectifier tube is connected to a first end of the fourth rectifier tube and the second AC end, a second end of the third rectifier tube is connected to a second end of the fourth rectifier tube and a second end of the first DC / DC module.

[0013] In the embodiment, the rectifier module comprises four rectifier tubes, and the control module can control the conduction or turn-off of the rectifier tubes in the rectifier module. The rectifier tube is different from a simple diode, so that the rectifier module can support bidirectional rectification, so that the energy conversion device can work in a forward charging mode (the energy conversion device can convert the AC power of the first AC end and the second AC end into DC power, and the DC power is output from the first DC end and the second DC end to the positive and negative poles of the battery, so as to realize charging of the battery) and a reverse discharging mode (the energy conversion device can convert the DC power of the first DC end and the second DC end into AC power, and the AC end is output from the first AC end and the second AC end to an AC load (a load supporting AC power supply), so as to realize power supply for the AC load), thereby expanding the application scenarios of the energy conversion device.

[0014] Optionally, the control module determines the duty cycle of the switch tube in the first DC / DC module according to the first sampling voltage and the first sampling current, to realize the AC-to-DC function of the energy conversion device, comprising:

[0015] In the case that the energy conversion device works in the continuous conduction mode CCM, the control module determines the duty cycle of the switch tube in the first DC / DC module according to the first sampling voltage, the second sampling voltage, the first sampling current and the second sampling current, to realize the AC-to-DC function of the energy conversion device, the second sampling voltage is the voltage between the first AC end and the second AC end, and the second sampling current is the current on the first inductor L1 in the first DC / DC module.

[0016] In the embodiments of the present application, the first sampling voltage is a sampling voltage between the first DC terminal and the second DC terminal, the first sampling voltage is a sampling voltage output by the energy conversion device when the energy conversion device works in the forward charging mode, and the control module can adjust the voltage output by the energy conversion device according to the sampling voltage output by the energy conversion device when the energy conversion device works in the forward charging mode, so as to ensure the stability of the voltage output by the energy conversion device. The first sampling current is a sampling current between the first DC terminal and the second DC terminal, the first sampling current is a sampling current output by the energy conversion device when the energy conversion device works in the forward charging mode, and the control module can adjust the current output by the energy conversion device according to the sampling current output by the energy conversion device when the energy conversion device works in the forward charging mode, so as to ensure the stability of the current output by the energy conversion device. The second sampling current is a sampling current on the first inductor, and the current on the first inductor changes with the change of the load of the output terminal (the first DC terminal and the second DC terminal) of the energy conversion device. The control module can adjust the current on the first inductor according to the sampling current on the first inductor, so that the current waveform on the first inductor can track the voltage between the first end of the first DC / DC module and the second end of the first DC / DC module, thereby achieving the purpose of power factor correction.

[0017] Optionally, the control module comprises a first voltage control loop, a first current control loop, a second current control loop, a first minimum module, a multiplier, a phase-locked loop (PLL), an absolute value module and a first wave driving module.

[0018] The first current control loop is configured to perform loop calculation on a result of subtraction of the first reference current from the first sampling current, and output a first loop calculation result.

[0019] The first voltage control loop is configured to perform loop calculation on a result of subtraction of the first reference voltage from the first sampling voltage, and output a second loop calculation result.

[0020] The first minimum module is configured to take the minimum value of the first loop calculation result and the second loop calculation result.

[0021] The PLL is configured to perform phase-locked loop calculation on the second sampling voltage, and output a third loop calculation result.

[0022] The absolute value module is configured to take the absolute value of the third loop calculation result, and obtain the absolute value of the third loop calculation result.

[0023] The multiplier is configured to multiply the minimum value of the first loop calculation result and the second loop calculation result by the absolute value of the third loop calculation result, and obtain a second reference current.

[0024] The second current control loop is configured to perform loop calculation on a result of subtraction between a second reference current and the second sampling current, and output a duty cycle of a switch tube in the first DC / DC module.

[0025] The first wave generation driving module is configured to output a driving signal of the switch tube in the first DC / DC module according to the duty cycle of the switch tube in the first DC / DC module.

[0026] Optionally, the control module determines the duty cycle of the switch tube in the first DC / DC module according to the first sampling voltage and the first sampling current, so as to realize the AC-to-DC function of the energy conversion device, and the method comprises the following steps.

[0027] In a case where the energy conversion device works in a discontinuous conduction mode (DCM), the control module determines the duty cycle of the switch tube in the first DC / DC module and a target switching frequency according to the first sampling voltage, the first sampling current and a second sampling current, so as to realize the AC-to-DC function of the energy conversion device, and the second sampling current is a current on a first inductor in the first DC / DC module.

[0028] Optionally, the control module comprises a second voltage control loop, a third current control loop, a second minimum taking module, a frequency calculation module and a second wave generation driving module.

[0029] The third current control loop is configured to perform loop calculation on a result of subtraction between a first reference current and the first sampling current, and output a fourth loop calculation result.

[0030] The second voltage control loop is configured to perform loop calculation on a result of subtraction between a first reference voltage and the first sampling voltage, and output a fifth loop calculation result.

[0031] The second minimum taking module is configured to take a minimum value in the fourth loop calculation result and the fifth loop calculation result.

[0032] The frequency calculation module is configured to determine a target switching frequency according to a real-time equivalent inductance of the energy conversion device, an initial equivalent inductance, and an initial switching frequency, the initial switching frequency being a switching frequency corresponding to the initial equivalent inductance of the energy conversion device, and the initial equivalent inductance being an equivalent inductance corresponding to the second sampling current being 0.

[0033] The second wave generation driving module is configured to output the driving signal of the switch tube in the first DC / DC module according to the minimum value in the fourth loop calculation result and the fifth loop calculation result and the target switching frequency.

[0034] Optionally, the control module determines a duty cycle of a switch tube in the first DC / DC module according to the first sampling voltage and the first sampling current, so as to realize an AC-to-DC function of the energy conversion device, comprising:

[0035] In a case where the energy conversion device works in a BCM (Boundary Conduction Mode), the control module determines the turn-on duration and the turn-off duration of the switch tube in the first DC / DC module according to the first sampling voltage, the first sampling current and a second sampling voltage, so as to realize the AC-to-DC function of the energy conversion device, the second sampling voltage being a voltage between the first AC terminal and the second AC terminal.

[0036] Optionally, the control module comprises a third voltage control loop, a fourth current control loop, a third minimum module, a turn-on time correction module, a turn-off time calculation module and a third wave generation driving module.

[0037] The fourth current control loop is configured to perform loop calculation on a result of subtraction of the first reference current from the first sampling current, and output a sixth loop calculation result.

[0038] The third voltage control loop is configured to perform loop calculation on a result of subtraction of the first reference voltage from the first sampling voltage, and output a seventh loop calculation result.

[0039] The third minimum module is configured to take a minimum value of the sixth loop calculation result and the seventh loop calculation result.

[0040] The turn-on time correction module is configured to determine a corrected turn-on duration according to the minimum value of the sixth loop calculation result and the seventh loop calculation result, the first sampling voltage and the second sampling voltage.

[0041] The turn-off time calculation module is configured to determine a corrected turn-off duration according to the corrected turn-on duration, the first sampling voltage and the second sampling voltage.

[0042] The third wave generation driving module is configured to output a driving signal of the switch tube in the first DC / DC module according to the corrected turn-on duration and the corrected turn-off duration.

[0043] Optionally, the control module determines a duty cycle of a switch tube in the first DC / DC module according to the first sampling voltage and the first sampling current, so as to realize an AC-to-DC function of the energy conversion device, comprising:

[0044] In a case where the energy conversion device operates in a discontinuous conduction mode (DCM), the control module determines a duty cycle of a switch tube in the first DC / DC module according to the first sampling voltage and the first sampling current, so as to realize an AC-to-DC function of the energy conversion device.

[0045] Optionally, the control module comprises a fourth voltage control loop, a fifth current control loop, a fourth minimum module and a fourth wave generation driving module.

[0046] The fifth current control loop is configured to perform loop calculation on a result of subtraction of the first reference current from the first sampling current, and output an eighth loop calculation result.

[0047] The fourth voltage control loop is configured to perform loop calculation on a result of subtraction of the first reference voltage from the first sampling voltage, and output a ninth loop calculation result.

[0048] The fourth minimum module is configured to take a minimum value of the eighth loop calculation result and the ninth loop calculation result as the duty cycle of the switch tube in the first DC / DC module.

[0049] The fourth wave generation driving module is configured to output a driving signal of the switch tube in the first DC / DC module according to the duty cycle of the switch tube in the first DC / DC module.

[0050] Optionally, the second inductor is an excitation inductor in a primary winding of the transformer.

[0051] In the embodiments of the present application, the second inductor can reuse the excitation inductor in the primary winding of the transformer, so as to improve the integration of the first DC / DC module, reduce the cost and volume of the first DC / DC module, and further reduce the cost and volume of the energy conversion device.

[0052] Optionally, each rectifier tube comprises an insulated gate bipolar transistor (IGBT) or a metal oxide semiconductor field effect transistor (MOSFET).

[0053] In the embodiments of the present application, the MOSFET can also be referred to as a MOS tube. The rectifier tube can be an IGBT or a MOS tube. The use of the IGBT as the rectifier tube can reduce the cost, and the use of the MOS tube as the rectifier tube can reduce the conduction loss.

[0054] The second aspect of the embodiments of the present application provides a vehicle comprising the energy conversion device of the first aspect of the embodiments of the present application and a battery, and the energy conversion device is configured to convert AC power into DC power to charge the battery.

[0055] The energy conversion device provided by the embodiment of the present application adopts a single-stage topology, and compared with a two-stage architecture adopting a PFC module and a DC / DC module, the number of active devices can be reduced, so that the cost and volume of the energy conversion device are reduced. The control module can determine the duty cycle of the switch tube in the first DC / DC module according to the first sampling voltage and the first sampling current, so as to realize the AC-DC function of the energy conversion device, and thus the energy conversion device works in the forward charging mode. BRIEF DESCRIPTION OF DRAWINGS

[0056] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0057] Figure 1 is a structure schematic diagram of an energy conversion device provided by the embodiment of the present application;

[0058] Figure 2 is a structure schematic diagram of a control module in a continuous conduction mode CCM provided by the embodiment of the present application;

[0059] Figure 3 is a schematic diagram of working waveforms in a switching cycle of the continuous conduction mode CCM provided by the embodiment of the present application;

[0060] Figure 4 is a structure schematic diagram of a control module in a discontinuous conduction mode DCM provided by the embodiment of the present application;

[0061] Figure 5 is a schematic diagram of working waveforms in a switching cycle of the discontinuous conduction mode DCM provided by the embodiment of the present application;

[0062] Figure 6 is a structure schematic diagram of a control module in a boundary conduction mode BCM provided by the embodiment of the present application;

[0063] Figure 7 is a schematic diagram of working waveforms in a switching cycle of the boundary conduction mode BCM provided by the embodiment of the present application;

[0064] Figure 8 is a structure schematic diagram of another control module in a discontinuous conduction mode DCM provided by the embodiment of the present application;

[0065] Figure 9 is a waveform schematic diagram of AC voltage, AC current and first capacitor voltage of a first AC end and a second AC end of an energy conversion device provided by the embodiment of the present application;

[0066] Figure 10 is a structural schematic diagram of a vehicle provided by an embodiment of the present application. DETAILED DESCRIPTION

[0067] The technical solutions in the embodiments of the present application will be clearly and completely described in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person skilled in the art without creative work fall within the scope of protection of the present application.

[0068] The terms "first", "second", and the like in the specification and claims of the present application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. 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 can optionally include steps or units not listed, or can optionally include other steps or units inherent to the process, product or device.

[0069] In the present application, the phrase "embodiment" means that the specific features, structures or characteristics described in combination with the embodiment can be included in at least one embodiment of the present application. The appearance of this phrase at various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment to other embodiments. It is explicitly and implicitly understood by a person skilled in the art that the embodiments described in the present application can be combined with other embodiments.

[0070] Please refer to Figure 1 , Figure 1 is a structural schematic diagram of an energy conversion device provided by an embodiment of the present application. As Figure 1 shown, the energy conversion device can include a rectifier module 10, at least one DC / DC module and a control module 30. The at least one DC / DC module can include one or more DC / DC modules. Figure 1 Taking an example that the at least one DC / DC module includes one DC / DC module.

[0071] The first end of the rectifier module 10 is connected to a first AC end (such as Figure 1 shown as AC_L), and the second end of the rectifier module 10 is connected to a second AC end (such as Figure 1a third end of the rectifier module 10 is connected to a first end of a first DC / DC module 21, a fourth end of the rectifier module 10 is connected to a second end of the first DC / DC module 21, a third end of the first DC / DC module 21 is connected to a first direct current end, and a fourth end of the first DC / DC module 21 is connected to a second direct current end; the first DC / DC module 21 is any one of the at least one direct current conversion module;

[0072] In a case where the energy conversion device works in the forward charging mode, the control module 30 determines a duty ratio of a switch tube in the first DC / DC module 21 according to a first sampling voltage (for example, V Figure 1 HV ), a first sampling current (for example, I Figure 1 HV ) to realize an alternating current conversion function of the energy conversion device; the first sampling voltage is a voltage between the first direct current end and the second direct current end, and the first sampling current is a current between the first direct current end and the second direct current end.

[0073] In a possible embodiment, the energy conversion device can realize an alternating current conversion function. At this time, the first alternating current end and the second alternating current end are used as alternating current input ends, and the first direct current end and the second direct current end are used as direct current output ends, and the energy conversion device can convert input alternating current into direct current output.

[0074] In a possible embodiment, the energy conversion device can realize a direct current conversion function. At this time, the first alternating current end and the second alternating current end are used as alternating current output ends, and the first direct current end and the second direct current end are used as direct current input ends, and the energy conversion device can convert input direct current into alternating current output.

[0075] For example, the energy conversion device can be a vehicle on-board charger. The on-board charger can be a bidirectional on-board charger, which can support alternating current conversion and direct current conversion.

[0076] In the embodiment, the energy conversion device can work in the reverse discharge mode and the forward charging mode, and can expand the application scenarios of the energy conversion device.

[0077] ​​When the energy conversion device works in the reverse discharge mode, the energy conversion device can realize the function of DC / AC. The energy conversion device can convert the direct current at the first direct current end and the second direct current end into alternating current, and the alternating current end outputs alternating current to an alternating current load (a load supporting alternating current power supply) from the first alternating current end and the second alternating current end, so as to realize power supply for the alternating current load.

[0078] When the energy conversion device works in the forward charging mode, the energy conversion device can realize the function of AC / DC. The energy conversion device can convert the alternating current at the first alternating current end and the second alternating current end into direct current, and the direct current outputs direct current to the positive and negative poles of the battery from the first direct current end and the second direct current end, so as to realize charging for the battery.

[0079] The rectifier module 10 can realize the function of bidirectional rectification. For example, when the energy conversion device works in the forward charging mode, the rectifier module 10 can convert the alternating voltage between the first alternating current end and the second alternating current end into direct voltage (for example, a steamed bun wave, which is a waveform after half-wave rectification, and can be a waveform after flipping the negative half cycle of a sine wave), and output the direct voltage to the first end of the first DC / DC module 21 and the second end of the first DC / DC module 21. When the energy conversion device works in the reverse discharge mode, the rectifier module 10 can also convert the direct voltage between the first end of the first DC / DC module 21 and the second end of the first DC / DC module 21 into alternating voltage, and output the alternating voltage to the first alternating current end and the second alternating current end.

[0080] The first DC / DC module 21 can realize the conversion of one direct voltage to another direct voltage. For example, when the energy conversion device works in the forward charging mode, the first DC / DC module 21 can convert the pulsating direct current waveform (for example, a steamed bun wave) between the third end of the rectifier module 10 and the fourth end of the rectifier module 10 into a straight-line direct current waveform, and output the straight-line direct current waveform to the first direct current end and the second direct current end. When the energy conversion device works in the reverse discharge mode, the first DC / DC module 21 can also convert the straight-line direct current waveform between the first direct current end and the second direct current end into a pulsating direct current waveform, and output the pulsating direct current waveform to the third end of the rectifier module 10 and the fourth end of the rectifier module 10.

[0081] The two-stage architecture of the PFC module and the DC / DC module needs to add an electrolytic capacitor (also known as a bus capacitor) between the PFC module and the DC / DC module for decoupling.

[0082] In the embodiment of the present application, the energy conversion device adopts a single-stage topology. Compared with a two-stage architecture adopting a PFC module and a DC / DC module, one DC / DC converter can be reduced, thereby reducing the number of active devices. The energy conversion device does not need to increase an electrolytic capacitor, thereby improving the power density of the energy conversion device, and reducing the cost and volume of the energy conversion device. The control module can determine the duty cycle of the switching tube in the first DC / DC module 21 according to the first sampling voltage and the first sampling current, so as to realize the AC-to-DC function of the energy conversion device, thereby enabling the energy conversion device to work in the forward charging mode.

[0083] In the embodiment of the present application, the energy conversion device works in the forward charging mode, and specifically can include any one of the following: continuous conduction mode (CCM), discontinuous conduction mode (DCM), and boundary conduction mode (BCM).

[0084] The at least one DC / DC module is connected in an interleaved and parallel manner, thereby improving the output power of the energy conversion device, and being applicable to a high-power scene.

[0085] As shown in FIG. 1, the energy conversion device includes a rectifier module 10, a control module 20, and at least one DC / DC module 21. Figure 1 As shown in FIG. 2, the first DC / DC module 21 includes a first capacitor C1, a second capacitor C2, a third capacitor C3, a first switching tube S1, a second switching tube S2, a first inductor L1, a second inductor L2, and a transformer T1. The first end of the first capacitor C1 is connected to the first end of the first inductor L1 and the third end of the rectifier module 10. The second end of the first inductor L1 is connected to the first end of the second capacitor C2 and the first end of the first switching tube S1. The second end of the second capacitor C2 is connected to the first end of the second inductor L2 and the first end of the primary winding of the transformer T1. The second end of the first capacitor C1 is connected to the second end of the first switching tube S1, the second end of the second inductor L2, the second end of the primary winding, and the fourth end of the rectifier module 10. The first end of the secondary winding of the transformer T1 is connected to the first end of the second switching tube S2. The second end of the second switching tube S2 is connected to the first end of the third capacitor C3 and the first DC terminal. The second end of the secondary winding is connected to the second end of the third capacitor C3 and the second DC terminal.

[0086] In the embodiment of the present application, the first DC / DC module 21 includes two switching tubes: the first switching tube S1 and the second switching tube S2. The traditional single-stage AC / DC module includes at least two bridge arms (at least four switching tubes). Compared with the traditional single-stage AC / DC module, the first DC / DC module 21 of the present application can reduce the number of switching tubes, thereby further reducing the cost and volume of the energy conversion device.

[0087] The first DC / DC module 21 can be based on a Single Ended Primary Inductor Converter (SEPIC) circuit and a transformer.

[0088] The transformer T1 can be an isolation transformer, and can achieve isolation between the AC end (the first AC end and the second AC end) and the DC end (the first DC end and the second DC end).

[0089] Optionally, the second inductor L2 is an excitation inductor in a primary winding of the transformer T1.

[0090] In the embodiments of the present application, the second inductor L2 can reuse the excitation inductor in the primary winding of the transformer T1, thereby improving the integration of the first DC / DC module 21, reducing the cost and volume of the first DC / DC module 21, and further reducing the cost and volume of the energy conversion device.

[0091] As shown in FIG. 1, the rectifier module 10 includes a first rectifier Q1, a second rectifier Q2, a third rectifier Q3, and a fourth rectifier Q4. Figure 1 The first end of the first rectifier Q1 is connected to the first end of the second rectifier Q2 and the first end of the first DC / DC module 21, the second end of the first rectifier Q1 is connected to the first end of the third rectifier Q3 and the first AC end, the second end of the second rectifier Q2 is connected to the first end of the fourth rectifier Q4 and the second AC end, and the second end of the third rectifier Q3 is connected to the second end of the fourth rectifier Q4 and the second end of the first DC / DC module 21.

[0092] In the embodiments of the present application, the rectifier module 10 includes four rectifiers, and the control module 30 can control the conduction or turn-off of the rectifiers in the rectifier module 10. The rectifiers are not the same as simple diodes, so that the rectifier module 10 can support bidirectional rectification, thereby allowing the energy conversion device to work in a forward charging mode (the energy conversion device can convert the AC power at the first AC end and the second AC end into DC power, and output the DC power from the first DC end and the second DC end to the positive and negative electrodes of the battery, thereby achieving charging of the battery) and a reverse discharging mode (the energy conversion device can convert the DC power at the first DC end and the second DC end into AC power, and output the AC power from the first AC end and the second AC end to an AC load (a load supporting AC power supply), thereby achieving power supply to the AC load), thereby expanding the application scenarios of the energy conversion device.

[0093] Optionally, each rectifier tube comprises an Insulate-Gate Bipolar Transistor (IGBT) or a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET).

[0094] In the embodiments of the present application, the MOSFET can also be referred to as a MOS tube or a MOS transistor. The rectifier tube can be an IGBT or a MOS tube. The rectifier tube using the IGBT can reduce the cost, and the rectifier tube using the MOS tube can reduce the conduction loss.

[0095] Optionally, the first switch tube S1 and the second switch tube S2 can both use the IGBT or the MOSFET.

[0096] Figure 1 The rectifier tube is taken as an example, Figure 2 The first switch tube S1 and the second switch tube S2 are taken as an example of the N-type MOS transistor. The N-type MOS transistor can be referred to as the NOMS tube. The MOSFET can be a silicon carbide (SiC) MOSFET or a gallium nitride (GaN) MOSFET. The silicon carbide MOSFET is a MOSFET using a silicon carbide material, and the gallium nitride MOSFET is a MOSFET using a gallium nitride material.

[0097] In the embodiments of the present application, the MOSFET can also be referred to as a MOS tube or a MOS transistor. The rectifier tube can be an IGBT or a MOS tube. The rectifier tube using the IGBT can reduce the cost, and the rectifier tube using the MOS tube can reduce the conduction loss.

[0098] The diode connected in parallel with each rectifier tube can be a body diode or a parasitic diode of the rectifier tube. The diode can play a role of freewheeling.

[0099] Optionally, the control module 30 determines the duty cycle of the switch tube in the first DC / DC module 21 according to the first sampling voltage and the first sampling current, to realize the AC-to-DC function of the energy conversion device, comprising:

[0100] When the energy conversion device operates in the continuous conduction mode (CCM), the control module 30 determines the duty cycle of the switch tube in the first DC / DC module 21 based on the first sampled voltage, the second sampled voltage, the first sampled current, and the second sampled current, so as to realize the AC-to-DC function of the energy conversion device. The second sampled voltage is the voltage between the first AC terminal and the second AC terminal, and the second sampled current is the current on the first inductor L1 in the first DC / DC module 21.

[0101] In the embodiment of the present application, the first sampled voltage is the sampled voltage between the first DC terminal and the second DC terminal. The first sampled voltage is the sampled voltage output by the energy conversion device when operating in the forward charging mode. The control module 30 can adjust the voltage output by the energy conversion device based on the sampled voltage output by the energy conversion device when operating in the forward charging mode, thereby ensuring the stability of the voltage output by the energy conversion device. The first sampled current is the sampled current between the first DC terminal and the second DC terminal. The first sampled current is the sampled current output by the energy conversion device when operating in the forward charging mode. The control module 30 can adjust the current output by the energy conversion device based on the sampled current output by the energy conversion device when operating in the forward charging mode, thereby ensuring the stability of the current output by the energy conversion device. The second sampling current is the sampling current on the first inductor L1. Since the current on the first inductor L1 changes with the load on the output end (the first DC end and the second DC end) of the energy conversion device, the control module 30 can adjust the current on the first inductor L1 based on the sampling current on the first inductor L1, so that the current waveform on the first inductor L1 can track the voltage between the first end and the second end of the first DC / DC module 21, thereby achieving the purpose of power factor correction.

[0102] See also Figure 2 , Figure 2 This is a schematic diagram of the structure of a control module in a continuous conduction mode (CCM) according to an embodiment of the present application. Figure 2 As shown, the control module 30 includes: a first voltage control loop, a first current control loop, a second current control loop, a first minimization module, a multiplier, a phase locked loop (PLL), an absolute value module and a first wave driving module.

[0103] The first current control loop is used to control the first reference current (such as Figure 2 I shown HV_Ref ) and the first sampling current (such as Figure 2 I shown HVThe first current control loop is used to perform loop calculation on the result of the subtraction operation of the first reference current (such as i HV_Ref -I HV ) and the first sampling current (such as i

[0104] The first voltage control loop is used to perform loop calculation on the result of the subtraction operation of the first reference voltage (such as V Figure 2 HV_Ref ) and the first sampling voltage (such as V Figure 2 HV ), and output a second loop calculation result; wherein the PI in the first voltage control loop is a proportional integral (PI) regulator, used to perform loop calculation on (V HV_Ref -V HV ) to obtain the second loop calculation result.

[0105] The first minimum module is used to take the minimum value of the first loop calculation result and the second loop calculation result.

[0106] The PLL is used to perform phase-locked loop calculation on the second sampling voltage (such as V Figure 2 ac ), and output a third loop calculation result. The third loop calculation result is cos(θ) as shown in Figure 2 , which is the cosine value of the phase angle of the second sampling voltage.

[0107] The absolute value module is used to take the absolute value of the third loop calculation result to obtain the absolute value of the third loop calculation result.

[0108] The multiplier is used to multiply the minimum value of the first loop calculation result and the second loop calculation result by the absolute value of the third loop calculation result to obtain a second reference current (such as i Figure 2 L1_Ref ).

[0109] The second current control loop is used to perform loop calculation on the result of the subtraction operation of the second reference current (such as i Figure 2 L1_Ref ) and the second sampling current (such as i Figure 3 L1 ), and output the duty cycle of the switch tube in the first DC / DC module 21.

[0110] ​​​​​​The first wave generating driving module is configured to output a driving signal of a switch tube in the first DC / DC module 21 according to a duty ratio of the switch tube in the first DC / DC module 21.

[0111] Figure 3 The first wave generating driving module in the first DC / DC module 21 can be a pulse width modulation (PWM) module. The first wave generating driving module can generate a wave signal of each switch tube (the first switch tube S1 and the second switch tube S2) according to a duty ratio of the switch tube in the first DC / DC module 21, and then generate a driving signal of each switch tube after amplifying and isolating the wave signal of each switch tube. The driving signal of the switch tube is used to drive the switch tube to turn on or turn off. As shown in Figure 3 , the driving signal of S1 is the driving signal of the first switch tube S1, the driving signal of S2 is the driving signal of the second switch tube S2, and the second switch tube S2 works in a synchronous rectification state.

[0112] When the energy conversion device works in the continuous conduction mode CCM, the gain characteristic of the energy conversion device is M = N × V HV / v rec = d / (1-d), where d is the duty ratio of the first switch tube S1, v rec is the input voltage of the first DC / DC module 21, and N is the turn ratio of the primary winding and the secondary winding of the transformer T1. Since v rec changes with V ac in the power frequency period, the duty ratio of the switch tube of the first DC / DC module 21 also changes in the power frequency period.

[0113] Figure 3 In the first DC / DC module 21, the first voltage control loop and the first current control loop are outer loops, and the second current control loop is an inner loop. The first voltage control loop and the first current control loop are used to control the output side voltage and current of the energy conversion device, and the two loops (the first voltage control loop and the first current control loop) output the smaller one after multiplication with the output of the phase-locked loop to determine the reference current of the second current control loop. The second current control loop controls the first inductor current i L1 of the first DC / DC module 21 to track the input voltage, thereby realizing the function of PFC.

[0114] Please refer to Figure 4 , Figure 4 is a schematic diagram of a working waveform in a switching period of the continuous conduction mode CCM provided by the embodiment of the present application. As shown in Figure 4 , i L1 is a waveform diagram of the current on the first inductor L1 changing with time, and i L2is a waveform diagram of the current change over time on the second inductor L2. S2 is a waveform diagram of the current change over time on the second switch S2, V GS1 is a waveform diagram of the drive signal of the first switch S1, V GS2 is a waveform diagram of the drive signal of the second switch S2. From Figure 4 It can be seen that, in a switching cycle, D1T S is the on duration of the first switch S1, D2T S is the on duration of the second switch S2.

[0115] Optionally, the control module 30 determines the duty cycle of the switch in the first DC / DC module 21 according to the first sampling voltage and the first sampling current, to realize the AC-to-DC function of the energy conversion device, including:

[0116] In the case that the energy conversion device works in the discontinuous conduction mode (DCM), the control module 30 determines the duty cycle of the switch in the first DC / DC module 21 and the target switching frequency according to the first sampling voltage, the first sampling current and the second sampling current, to realize the AC-to-DC function of the energy conversion device, the second sampling current being the current on the first inductor L1 in the first DC / DC module 21.

[0117] In the embodiments of the present application, the first sampling voltage is the sampling voltage between the first DC terminal and the second DC terminal, and the first sampling voltage is the sampling voltage output when the energy conversion device works in the forward charging mode. The control module 30 can adjust the voltage output by the energy conversion device according to the sampling voltage output when the energy conversion device works in the forward charging mode, so as to ensure the stability of the voltage output by the energy conversion device. The first sampling current is the sampling current between the first DC terminal and the second DC terminal, and the first sampling current is the sampling current output when the energy conversion device works in the forward charging mode. The control module 30 can adjust the current output by the energy conversion device according to the sampling current output when the energy conversion device works in the forward charging mode, so as to ensure the stability of the current output by the energy conversion device.

[0118] When the current in the second switch S2 drops to zero in advance during the first switch S1 is off, the first DC / DC module 21 enters the discontinuous conduction mode DCM. In the parameter design of the first DC / DC module 21, by selecting appropriate inductance values L1 (the inductance value of the first inductor L1), L2 (the inductance value of the second inductor L2) and the switching frequency (the switching frequency of the first switch S1 and the second switch S2), the first DC / DC module 21 can always work in the discontinuous conduction mode DCM in the full operating range. Through derivation under the discontinuous conduction mode DCM, the expression of the input current of the energy conversion device is:

[0119]

[0120] Wherein, L eq is the equivalent inductance of the energy conversion device, L eq =L1×L2 / (L1+L2). d1 is the duty ratio of the first switch S1, T s is the switching period of the first switch S1 and the second switch S2, which is the reciprocal of the above-mentioned switching frequency. v ac (t) is the time-varying input voltage of the energy conversion device, i ac (t) is the time-varying input current of the energy conversion device.

[0121] As can be seen from the expression of the input current of the energy conversion device, under the discontinuous conduction mode DCM, when L eq , T s and d1 are fixed, the ratio of v ac (t) to i ac (t) is a constant value, the input end of the energy conversion device is resistive, and the first DC / DC module 21 has the natural PFC characteristic. For the first DC / DC module 21, L eq is ignored. Within the power frequency period (the power frequency period refers to the time required for the power frequency alternating current to complete a complete waveform change, for example, if the power frequency is 50 Hz, the corresponding power frequency period is 0.02 seconds), only one voltage outer ring and one current outer ring are needed to simultaneously realize the functions of input power factor correction and output power regulation, and the loop output of the competition between the one voltage outer ring and the one current outer ring determines the duty ratio of the first switch S1. Since the loop bandwidth of the voltage outer ring and the current outer ring is low, d1 is basically unchanged within the power frequency period, so the natural PFC can be realized.

[0122] In actual application, L eq is difficult to be fixed within the power frequency period. For example, when the first inductor L1 adopts a powder core inductor, the inductance of the first inductor L1 decreases with the increase of the current in the first inductor L1, so L eqDuring the power frequency cycle, it will change with the instantaneous input current. As the input current value increases, L eq The natural PFC characteristics in discontinuous conduction mode (DCM) are destroyed.

[0123] In L eq When the input current of the energy conversion device changes, the input current expression in DCM can be further rewritten as follows:

[0124]

[0125] Among them, L eq is the equivalent inductance of the energy conversion device, t on is the constant on-time within one power frequency cycle, f s is the switching frequency within the power frequency cycle, v ac (t) is the input voltage of the energy conversion device that changes with time, i ac (t) is the input current of the energy conversion device that changes with time.

[0126] It can be seen that constant-on-time (COT) control is adopted and variable frequency regulation is added to make f s / L eq The ratio is fixed so that v ac (t) and i ac The ratio of (t) is a constant value, and the input end of the energy conversion device becomes resistive, thereby maintaining the natural PFC characteristics in the discontinuous conduction mode DCM.

[0127] See also Figure 4 , Figure 4 1 is a schematic diagram of the structure of a control module in a discontinuous conduction mode DCM provided by an embodiment of the present application. Figure 4 As shown, the control module includes: a second voltage control loop, a third current control loop, a second minimization module, a frequency calculation module and a second wave driving module.

[0128] The third current control loop is used to control the first reference current (such as Figure 4 I shown HV_Ref ) and the first sampling current (such as Figure 4 I shown HV ) is subtracted and the result of the loop calculation is output to the fourth loop calculation result. Among them, the PI in the third current control loop is a proportional integral (PI) regulator, which is used to adjust (I HV_Ref -I HV ) to perform loop calculation and obtain the fourth loop calculation result.

[0129] The second voltage control loop is used to control the first reference voltage (such as Figure 5 The V HV_Ref ) and the first sampling voltage (such as Figure 5 The V HV ) is subtracted and the result of the loop calculation is output to the fifth loop calculation result. Among them, the PI in the second voltage control loop is a proportional integral (PI) regulator, which is used to adjust (V HV_Ref -V HV ) to perform loop calculation and obtain the fifth loop calculation result.

[0130] The second minimum module is used to obtain the minimum value of the fourth loop calculation result and the fifth loop calculation result (such as Figure 5 The t shown on ).

[0131] The frequency calculation module is used to calculate the initial equivalent inductance L of the energy conversion device according to the eq0 , initial switching frequency f s0 and real-time equivalent inductance L eq (i L1 ) Determine the target switching frequency f s The initial switching frequency is the switching frequency corresponding to when the equivalent inductance of the energy conversion device is the initial equivalent inductance. The initial equivalent inductance is the equivalent inductance corresponding to when the second sampling current (the second sampling current is the current on the first inductor L1) is 0. The target switching frequency can be obtained according to the following formula:

[0132]

[0133] Among them, f s is the target switching frequency, L eq0 is the initial equivalent inductance of the energy conversion device, f s0 is the initial switching frequency, f s0 is the switching frequency corresponding to the second sampling current being 0, L eq (i L1 ) is the real-time equivalent inductance, that is, the inductor current is i L1 The corresponding equivalent inductance, L eq with i L1 The relationship can be obtained from the magnetic handbook used.

[0134] The second wave driving module is used to calculate the minimum value t of the fourth loop calculation result and the fifth loop calculation result. on , the target switching frequency f s Outputs a driving signal for the switch tube in the first DC / DC module 21 .

[0135] Figure 5 The second wave driving module in the embodiment can be a pulse width modulation (PWM) module. The second wave driving module can generate a wave signal for each switch tube (the first switch tube S1 and the second switch tube S2) according to the duty cycle and target switching frequency of the switch tubes in the first DC / DC module 21, and then amplify and isolate the wave signal of each switch tube to generate a drive signal for each switch tube. The drive signal of the switch tube is used to drive the switch tube to be turned on or off. Figure 6 As shown, the driving signal of S1 is the driving signal of the first switch tube S1, and the driving signal of S2 is the driving signal of the second switch tube S2.

[0136] The output of the second minimum module (the minimum value of the fourth loop calculation result and the fifth loop calculation result) determines the conduction time of the first switch tube S1, and k0 is defined as f s0 / L eq0 , where L eq0 is the initial equivalent inductance of the energy conversion device, f s0 Is the initial switching frequency corresponding to the second sampling current of 0. The switching frequency in the power frequency cycle satisfies f s = k0 × L eq , due to L eq With current i L1 changes, so L can be obtained by fitting eq with i L1 The relationship between L eq (i L1 )express.

[0137] See also Figure 6 , Figure 6 Schematic diagram of a working waveform in a switching cycle of a discontinuous conduction mode DCM provided by an embodiment of the present application. Figure 6 As shown, i L1 is the waveform of the current on the first inductor L1 changing with time, i L2 is a waveform diagram showing the current on the second inductor L2 changing with time. S2 is the waveform of the current on the second switch tube S2 changing with time, V GS1 is the waveform of the driving signal of the first switch tube S1, V GS2 is the waveform of the driving signal of the second switch tube S2. L1,pk is the maximum value of the current on the first inductor L1, i L1_0 is the minimum value of the current on the first inductor L1. L2,pk is the negative maximum value of the current on the second inductor L2.Figure 6 It can be seen that in one switching cycle, D1T S is the on-time of the first switch S1, D2T S is the on-time of the second switch S2, D3Ts=Ts-D1Ts-D2Ts, D3Ts is the time during which the current of the second switch S2 is zero (i.e., D3Ts is the off-time of the second switch S2). Where Ts is a switching cycle, D1 is the duty cycle of the first switch S1, and D2 is the duty cycle of the second switch S2.

[0138] Optionally, the control module 30 determines the duty cycle of the switch tube in the first DC / DC module 21 according to the first sampled voltage and the first sampled current to implement the AC-to-DC function of the energy conversion device, including:

[0139] When the energy conversion device operates in the critical conduction mode (BCM), the control module 30 determines the on-time and off-time of the switch tube in the first DC / DC module 21 according to the first sampled voltage, the first sampled current, and the second sampled voltage to realize the AC-to-DC function of the energy conversion device. The second sampled voltage is the voltage between the first AC terminal and the second AC terminal.

[0140] In the embodiment of the present application, the first sampled voltage is the sampled voltage between the first DC terminal and the second DC terminal. The first sampled voltage is the sampled voltage output by the energy conversion device when operating in the forward charging mode. The control module 30 can adjust the voltage output by the energy conversion device based on the sampled voltage output by the energy conversion device when operating in the forward charging mode, thereby ensuring the stability of the voltage output by the energy conversion device. The first sampled current is the sampled current between the first DC terminal and the second DC terminal. The first sampled current is the sampled current output by the energy conversion device when operating in the forward charging mode. The control module 30 can adjust the current output by the energy conversion device based on the sampled current output by the energy conversion device when operating in the forward charging mode, thereby ensuring the stability of the current output by the energy conversion device. The second sampled voltage is the voltage between the first AC terminal and the second AC terminal. The second sampled voltage is the sampled voltage input by the energy conversion device when operating in the forward charging mode. The on-time and off-time of the switch in the first DC / DC module 21 can be corrected based on the second sampled voltage, thereby enabling the first DC / DC module 21 to achieve natural PFC.

[0141] See also Figure 6 , Figure 6 1 is a schematic diagram of a control module in a critical conduction mode BCM according to an embodiment of the present application. Figure 6As shown, the control module includes: a third voltage control loop, a fourth current control loop, a third minimization module, an on-time correction module, an off-time calculation module, and a third wave driving module;

[0142] The fourth current control loop is used to control the first reference current (such as Figure 6 I shown HV_Ref ) and the first sampling current (such as Figure 6 I shown HV ) is subtracted and the result of the loop calculation is outputted as the sixth loop calculation result. Among them, the PI in the fourth current control loop is a proportional integral (PI) regulator, which is used to adjust (I HV_Ref -I HV ) to perform loop calculation and obtain the sixth loop calculation result.

[0143] The third voltage control loop is used to control the first reference voltage (such as Figure 6 The V HV_Ref ) and the first sampling voltage (such as Figure 6 The V HV ) is subtracted and the result of loop calculation is output to the seventh loop calculation result. Among them, the PI in the third voltage control loop is a proportional integral (PI) regulator, which is used to adjust (V HV_Ref -V HV ) to perform loop calculation and obtain the seventh loop calculation result.

[0144] The third min-sum module is used to take the minimum value between the sixth loop calculation result and the seventh loop calculation result. The output result of the third min-sum module is T on0 , T on0 is the initial turn-on duration of the first switch tube S1 in one switching cycle.

[0145] The opening time correction module is used to adjust the opening time according to the minimum value (such as Figure 6 T shown on0 ), the first sampling voltage (such as Figure 6 The V HV ) and the second sampling voltage (as Figure 6 The V ac ) Determine the revised activation duration (e.g. Figure 6 The t shown on ).

[0146] The off time calculation module is used to calculate the off time according to the modified on time (such as Figure 6 The t shown on), the first sampling voltage (such as Figure 6 The V HV ) and the second sampling voltage (as Figure 7 The V ac ) to determine the shutdown duration (e.g. Figure 7 The t shown off ).

[0147] The third wave driving module is used to adjust the opening time according to the revised opening time (such as Figure 7 The t shown on ) and the off time (e.g. Figure 7 The t shown off ) outputs a driving signal for the switch tube in the first DC / DC module 21.

[0148] Figure 7 The third wave driving module in the embodiment can be a pulse width modulation (PWM) module. The third wave driving module can generate a wave signal for each switch tube (the first switch tube S1 and the second switch tube S2) according to the duty cycle of the switch tube in the first DC / DC module 21, and then amplify and isolate the wave signal of each switch tube to generate a drive signal for each switch tube. The drive signal of the switch tube is used to drive the switch tube to be turned on or off. Figure 8 As shown, the driving signal of S1 is the driving signal of the first switch tube S1, and the driving signal of S2 is the driving signal of the second switch tube S2.

[0149] See also Figure 8 , Figure 8 Schematic diagram of a working waveform in a switching cycle of a critical conduction mode BCM provided by an embodiment of the present application. Figure 8 As shown, i L1 is the waveform of the current on the first inductor L1 changing with time, i L2 is a waveform diagram showing the current on the second inductor L2 changing with time. S2 is the waveform of the current on the second switch tube S2 changing with time, V GS1 is the waveform of the driving signal of the first switch tube S1, V GS2 is the waveform diagram of the driving signal of the second switch tube S2. Figure 8 It can be seen that in one switching cycle, D1T S is the on-time of the first switch S1, D2T S is the on-time of the second switch tube S2.

[0150] like Figure 8 As shown, when the first switch tube S1 is turned on for a period of time (D1T sthe time (D2T s ) for the current of the second switch S2 to drop from the peak value to 0 s satisfies D1T s +D2T s =T on , the first DC / DC module 21 works in the BCM. In the BCM, the turn-on time t off and the turn-off time t on of the first switch S1 satisfy:

[0151]

[0152] where t off is the turn-on time of the first switch S1 in a switching period, t ac is the turn-off time of the first switch S1 in a switching period, and v eq is the second sampling voltage.

[0153] Through derivation, the expression of the input current of the energy conversion device in the BCM can be obtained as:

[0154]

[0155] where L eq is the equivalent inductance of the energy conversion device, L HV =L1×L2 / (L1+L2). V on is the first sampling voltage, t ac，pk is the turn-on time of the first switch S1 in a switching period, V ac is the maximum value of v ac (t) in a switching period. v ac (t) is the input voltage of the energy conversion device varying with time, and i s (t) is the input current of the energy conversion device varying with time. Where ω=2π / Ts, T ac,pk is the switching period.

[0156] It can be seen that, since V HV / V on is not 0, the first DC / DC module 21 controlled by the COT cannot achieve natural PFC. The turn-on time of the first switch S1 can be corrected on the basis of the COT control, so that the corrected turn-on time of the first switch S1 satisfies the following condition:

[0157]

[0158] where t on0is the initial turn-on duration of the first switch S1 in a switching cycle, V HV is the first sampling voltage, v ac is the second sampling voltage.

[0159] Substituting the above formula can obtain:

[0160]

[0161] wherein, T on0 is the initial turn-on duration of the first switch S1 in a switching cycle, L eq is the equivalent inductance of the energy conversion device, v ac (t) is the time-varying input voltage of the energy conversion device, i ac (t) is the time-varying input current of the energy conversion device.

[0162] It can be seen that, after the turn-on duration of the first switch S1 is corrected, v ac (t) and i ac (t) is a constant value, the input end of the energy conversion device is resistive, and the first DC / DC module 21 can realize natural PFC.

[0163] Optionally, the control module 30 determines the duty cycle of the switch in the first DC / DC module 21 according to the first sampling voltage and the first sampling current, so as to realize the AC-to-DC function of the energy conversion device, which comprises:

[0164] In the case that the energy conversion device works in the discontinuous conduction mode (DCM), the control module 30 determines the duty cycle of the switch in the first DC / DC module 21 according to the first sampling voltage and the first sampling current, so as to realize the AC-to-DC function of the energy conversion device.

[0165] In the embodiment of the application, the first sampling voltage is the sampling voltage between the first DC end and the second DC end, and the first sampling voltage is the sampling voltage output when the energy conversion device works in the forward charging mode. The control module 30 can adjust the voltage output by the energy conversion device according to the sampling voltage output when the energy conversion device works in the forward charging mode, so as to ensure the stability of the voltage output by the energy conversion device. The first sampling current is the sampling current between the first DC end and the second DC end, and the first sampling current is the sampling current output when the energy conversion device works in the forward charging mode. The control module 30 can adjust the current output by the energy conversion device according to the sampling current output when the energy conversion device works in the forward charging mode, so as to ensure the stability of the current output by the energy conversion device.

[0166] Please refer to Figure 8 , Figure 8This is a structural diagram of another control module in discontinuous conduction mode DCM provided by an embodiment of the present application. Figure 8 As shown, the control module 30 includes: a fourth voltage control loop, a fifth current control loop, a fourth reduction module and a fourth wave driving module.

[0167] The fifth current control loop is used to control the first reference current (such as Figure 9 I shown HV_Ref ) and the first sampling current (such as Figure 9 I shown HV ) is subtracted and the result of the loop calculation is outputted as the eighth loop calculation result. Among them, the PI in the fifth current control loop is a proportional integral (PI) regulator, which is used to adjust (I HV_Ref -I HV ) to perform loop calculation and obtain the eighth loop calculation result.

[0168] The fourth voltage control loop is used to control the first reference voltage (such as Figure 9 The V HV_Ref ) and the first sampling voltage (such as Figure 1 The V HV ) is subtracted and the result of the loop calculation is outputted as the ninth loop calculation result. Among them, the PI in the fourth voltage control loop is a proportional integral (PI) regulator, which is used to adjust (V HV_Ref -V HV ) to perform loop calculation and obtain the ninth loop calculation result.

[0169] The fourth minimization module is used to use the minimum value of the eighth loop calculation result and the ninth loop calculation result as the duty cycle of the switch tube in the first DC / DC module 21 (such as Figure 10 d) shown.

[0170] The fourth wave driving module is used to output a driving signal for the switch tube in the first DC / DC module 21 according to the duty cycle of the switch tube in the first DC / DC module 21 .

[0171] Figure 10 The second wave driving module in the embodiment can be a pulse width modulation (PWM) module. The second wave driving module can generate a wave signal for each switch tube (the first switch tube S1 and the second switch tube S2) according to the duty cycle of the switch tube in the first DC / DC module 21, and then amplify and isolate the wave signal of each switch tube to generate a drive signal for each switch tube. The drive signal of the switch tube is used to drive the switch tube to be turned on or off.Figure 10 As shown, the driving signal of S1 is the driving signal of the first switch tube S1, and the driving signal of S2 is the driving signal of the second switch tube S2.

[0172] See also Figure 10 , Figures 1 to 9 : is a waveform diagram of the AC voltage, AC current and first capacitor voltage at the first AC end and the second AC end of an energy conversion device provided by an embodiment of the present application. ​ As shown, when the energy conversion device operates in the forward charging mode, the AC voltage is the AC voltage of the first AC end and the second AC end of the energy conversion device, the AC current is the AC current of the first AC end and the second AC end of the energy conversion device, and the first capacitor voltage is ​ The voltage of the first capacitor C1 in the circuit is 311V. The amplitude of the AC voltage and the first capacitor voltage is 311V, and the frequency of the AC voltage and the AC current is 50Hz.

[0173] See also ​ , ​ This is a schematic diagram of the structure of a vehicle provided in an embodiment of the present application. ​ As shown, the vehicle may include an energy conversion device 100 and a battery 200. Battery 200 may be a power battery on the vehicle. The vehicle may be an electric vehicle. Energy conversion device 100 may be used to convert alternating current (AC) into direct current (DC) to charge battery 200.

[0174] Optionally, the battery 200 can input direct current into the energy conversion device 100, and the energy conversion device 100 converts the input direct current into an alternating current to supply power to an AC load.

[0175] ​ The specific structure and working principle of the energy conversion device 100 can be found in the above ​ The embodiments shown are not described in detail here.

[0176] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0177] In the several embodiments provided in this 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 merely illustrative. For example, the division of the units described is merely a logical functional division. In actual implementation, other division methods may be used. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not implemented.

Claims

1. An energy conversion device, characterized by, The energy conversion device comprises a rectifier module, at least one DC / DC module and a control module, a first end of the rectifier module is connected to a first alternating current end, a second end of the rectifier module is connected to a second alternating current end, a third end of the rectifier module is connected to a first end of the first DC / DC module, a fourth end of the rectifier module is connected to a second end of the first DC / DC module, a third end of the first DC / DC module is connected to a first direct current end, and a fourth end of the first DC / DC module is connected to a second direct current end; the first DC / DC module is any one of the at least one DC / DC module; In a case where the energy conversion device works in a forward charging mode, the control module determines a duty cycle of a switch tube in the first DC / DC module according to a first sampling voltage and a first sampling current, so as to realize an alternating current-direct current function of the energy conversion device; the first sampling voltage is a voltage between the first direct current end and the second direct current end, and the first sampling current is a current between the first direct current end and the second direct current end; In a case where the energy conversion device works in a discontinuous conduction mode (DCM), the control module comprises a second voltage control loop, a third current control loop, a second minimum taking module, a frequency calculation module and a second wave generation driving module; The third current control loop is used for loop calculation on a result of subtraction of a first reference current from the first sampling current, and outputs a fourth loop calculation result; The second voltage control loop is used for loop calculation on a result of subtraction of a first reference voltage from the first sampling voltage, and outputs a fifth loop calculation result; The second minimum taking module is used for taking a minimum value of the fourth loop calculation result and the fifth loop calculation result; The frequency calculation module is used for determining a target switching frequency according to a real-time equivalent inductance of the energy conversion device, an initial equivalent inductance, and an initial switching frequency; the initial switching frequency is a switching frequency corresponding to the initial equivalent inductance of the energy conversion device; the initial equivalent inductance is an equivalent inductance corresponding to a second sampling current of 0; the second sampling current is a current on a first inductor in the first DC / DC module; The second wave generation driving module is used for outputting a driving signal of the switch tube in the first DC / DC module according to the minimum value of the fourth loop calculation result and the fifth loop calculation result, and the target switching frequency.

2. The energy conversion device of claim 1, wherein, The first DC / DC module comprises a first capacitor, a second capacitor, a third capacitor, a first switch tube, a second switch tube, a first inductor, a second inductor and a transformer; a first end of the first capacitor is connected to a first end of the first inductor and a third end of the rectifier module; a second end of the first inductor is connected to a first end of the second capacitor and a first end of the first switch tube; a second end of the second capacitor is connected to a first end of the second inductor and a first end of a primary winding of the transformer; a second end of the first capacitor is connected to a second end of the first switch tube, a second end of the second inductor, a second end of the primary winding and a fourth end of the rectifier module; a first end of a secondary winding of the transformer is connected to a first end of the second switch tube; a second end of the second switch tube is connected to a first end of the third capacitor and the first DC end; and a second end of the secondary winding is connected to a second end of the third capacitor and the second DC end.

3. The energy conversion device of claim 2, wherein, The rectifier module comprises a first rectifier tube, a second rectifier tube, a third rectifier tube and a fourth rectifier tube; a first end of the first rectifier tube is connected to a first end of the second rectifier tube and a first end of the first DC / DC module; a second end of the first rectifier tube is connected to a first end of the third rectifier tube and the first AC end; a second end of the second rectifier tube is connected to a first end of the fourth rectifier tube and the second AC end; and a second end of the third rectifier tube is connected to a second end of the fourth rectifier tube and a second end of the first DC / DC module.

4. The energy conversion device of claim 2 or 3, wherein, The control module determines a duty cycle of a switch tube in the first DC / DC module according to a first sampling voltage and a first sampling current, so as to realize an AC-to-DC function of the energy conversion device, and the method comprises the following steps of: In a case where the energy conversion device works in a discontinuous conduction mode (DCM), the control module determines a duty cycle and a target switching frequency of a switch tube in the first DC / DC module according to the first sampling voltage, the first sampling current and the second sampling current, so as to realize the AC-to-DC function of the energy conversion device.

5. The energy conversion device of any one of claims 1 to 3, wherein, The control module determines a duty cycle of a switch tube in the first DC / DC module according to a first sampling voltage and a first sampling current, so as to realize an AC-to-DC function of the energy conversion device, and the method comprises the following steps of: In a case where the energy conversion device works in a boundary conduction mode (BCM), the control module determines a turn-on time and a turn-off time of a switch tube in the first DC / DC module according to the first sampling voltage, the first sampling current and a second sampling voltage, so as to realize the AC-to-DC function of the energy conversion device, wherein the second sampling voltage is a voltage between the first AC end and the second AC end; In a case where the energy conversion device works in a boundary conduction mode (BCM), the control module comprises a third voltage control loop, a fourth current control loop, a third minimum module, a turn-on time correction module, a turn-off time calculation module and a third wave generation driving module. The fourth current control loop is configured to perform loop calculation on a result of a subtraction operation of the first reference current and the first sampling current, and output a sixth loop calculation result; The third voltage control loop is configured to perform loop calculation on a result of a subtraction operation of the first reference voltage and the first sampling voltage, and output a seventh loop calculation result; The third minimum module is configured to take a minimum value of the sixth loop calculation result and the seventh loop calculation result; The turn-on time correction module is configured to determine a corrected turn-on time according to the minimum value of the sixth loop calculation result and the seventh loop calculation result, the first sampling voltage and the second sampling voltage; The turn-off time calculation module is configured to determine a turn-off time according to the corrected turn-on time, the first sampling voltage and the second sampling voltage; The third wave generation driving module is configured to output a driving signal of a switch tube in the first DC / DC module according to the corrected turn-on time and the turn-off time.

6. A vehicle characterized by comprising: An energy conversion device and a battery, the energy conversion device is configured to convert alternating current into direct current to charge the battery.

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