Energy conversion device and vehicle

Abstract

The embodiment of the invention provides an energy conversion device and a vehicle, 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 with a first AC end, a second end of the rectifier module is connected with a second AC end, a third end of the rectifier module is connected with a first end of the first DC / DC module, and a second end of the first DC / DC module is connected with a second AC end. The fourth end of the rectifier module is connected with the second end of the first DC / DC module, the third end of the first DC / DC module is connected with the first DC end, and the fourth end of the first DC / DC module is connected with the second DC end; under the condition that the energy conversion device works in a reverse discharge mode, the control module determines the duty ratio of a switching tube in the first DC / DC module according to the first sampling voltage or the second sampling voltage, and controls a rectifier tube in the rectifier module to be switched on or switched off, so that the direct current-to-alternating current function of the energy conversion device is achieved. The volume and the cost of the energy conversion device can be reduced.

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, onboard chargers (OBCs) are gaining increasing attention as energy conversion devices for electric vehicles. These devices convert AC power into DC power to charge the high-voltage batteries within the electric vehicle. These devices typically utilize a two-stage architecture consisting of a power factor correction (PFC) module and a direct current / direct current (DC / DC) converter. This increases the size and cost of the energy conversion device, resulting in lower 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 rectifier module, at least one DC / DC converter module, and a control module, wherein a first end of the rectifier module is connected to a first AC end, a second end of the rectifier module is connected to a second AC 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 DC end, and a fourth end of the first DC / DC module is connected to a second DC end; the first DC / DC module is any one of the at least one DC / DC converter module; When the energy conversion device operates in the reverse discharge mode, the control module determines the duty cycle of the switching tube in the first DC / DC module according to the first sampled voltage or the second sampled voltage, and controls the on or off of the rectifier tube in the rectifier module to achieve the DC-to-AC function of the energy conversion device; the first sampled voltage is the sampled voltage between the first end and the second end of the rectifier module, and the second sampled voltage is the sampled voltage between the first end and the second end of the first DC / DC module.

[0005] The energy conversion device of the present embodiment adopts a single-stage topology. Compared to a two-stage architecture employing a PFC module and a DC / DC module, this reduces the number of active components, thereby reducing the cost and size of the energy conversion device. The control module can determine the duty cycle of the switching transistor in the first DC / DC module based on the first sampled voltage or the second sampled voltage, and control the on / off switching of the rectifier transistor in the rectifier module to achieve the DC-to-AC conversion function of the energy conversion device, thereby enabling the energy conversion device to operate in a reverse discharge mode, expanding the application scenarios of the energy conversion device.

[0006] At least one DC / DC module is connected in an interleaved parallel manner to increase the output power of the energy conversion device, which can be applied to high-power scenarios.

[0007] Optionally, the first DC / DC module includes: a first capacitor, a second capacitor, a third capacitor, a first switching tube, a second switching tube, a first inductor, a second inductor and a transformer; the first end of the first capacitor is connected to the first end of the first inductor and the third end of the rectifier module, the second end of the first inductor is connected to the first end of the second capacitor and the first end of the first switching tube, the second end of the second capacitor is connected to the first end of the second inductor and the first end of the primary winding of the transformer, the second end of the first capacitor is connected to the second end of the first switching tube, the second end of the second inductor, the second end of the primary winding and the fourth end of the rectifier module; the first end of the secondary winding of the transformer is connected to the first end of the second switching tube, the second end of the second switching tube is connected to the first end of the third capacitor and the first DC end, and the second end of the secondary winding is connected to the second end of the third capacitor and the second DC end.

[0008] In this embodiment of the present application, the first DC / DC module includes two switching transistors: a first switching transistor and a second switching transistor. A conventional single-stage alternating current / direct current (AC / DC) module includes at least two bridge arms (at least four switching transistors). Compared to conventional single-stage AC / DC modules, the first DC / DC module in this embodiment can reduce the number of switching transistors, thereby further reducing the cost and size of the energy conversion device.

[0009] The transformer may be an isolation transformer, which 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).

[0010] Optionally, the second inductor is the magnetizing inductor in the primary winding of the transformer.

[0011] In an embodiment of the present application, the second inductor can reuse the magnetizing inductance in the primary winding of the transformer, thereby improving the integration of the first DC / DC module, reducing the cost and volume of the first DC / DC module, and further reducing the cost and volume of the energy conversion device.

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

[0013] In an embodiment of the present application, the rectifier module includes four rectifier tubes, and the control module can control the conduction or shutdown of the rectifier tubes in the rectifier module. The rectifier tubes are different from simple diodes, so that the rectifier module can support bidirectional rectification, so that the energy conversion device can work in both 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, thereby charging the battery), and reverse discharge 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 the AC load (a load that supports AC power supply), thereby powering the AC load), expanding the application scenarios of the energy conversion device.

[0014] Optionally, each rectifier tube includes an insulated gate bipolar transistor IGBT or a metal oxide semiconductor field effect transistor MOSFET.

[0015] In the embodiment of the present application, MOSFET can also be called MOS tube. The rectifier tube can be an IGBT or a MOS tube. Using IGBT as the rectifier tube can reduce cost, while using MOS tube as the rectifier tube can reduce conduction loss.

[0016] Optionally, the control module determines the duty cycle of the switch tube in the first DC / DC module according to the first sampled voltage or the second sampled voltage, and controls the on or off of the rectifier tube in the rectifier module to realize the DC-to-AC function of the energy conversion device, including: The control module determines the duty cycle of the switch tube in the first DC / DC module based on the first sampled voltage or the second sampled voltage and the first sampled current, and controls the on or off of the rectifier tube in the rectifier module to achieve the DC-to-AC function of the energy conversion device, where the first sampled current is the current on the first inductor.

[0017] In an embodiment of the present application, the first sampled voltage is the sampled voltage output by the energy conversion device when operating in reverse discharge mode. The control module can adjust the output voltage of the energy conversion device based on the sampled voltage output by the energy conversion device when operating in reverse discharge mode, thereby ensuring the stability of the output voltage of the energy conversion device. The first sampled current is the sampled current of the first inductor. Because the current of the first inductor varies with the load at the output terminal (first AC terminal, second AC terminal) of the energy conversion device, the control module can adjust the current of the first inductor based on the sampled current of the first inductor, thereby improving the dynamic characteristics of the load at the output terminal of the energy conversion device and providing current limiting. When the energy conversion device operates in reverse discharge mode, the sampled current of the first inductor is the sampled current output by the energy conversion device. The control module determines the duty cycle of the switching transistor in the first DC / DC module based on the first sampled voltage or the second sampled voltage and the first sampled current, thereby ensuring the stability of the output voltage and current of the energy conversion device when the energy conversion device operates in reverse discharge mode.

[0018] Optionally, the control module determines the duty cycle of the switch tube in the first DC / DC module according to the first sampled voltage or the second sampled voltage and the first sampled current, and controls the on or off of the rectifier tube in the rectifier module to realize the DC-to-AC function of the energy conversion device, including: The control module determines a first reference current according to the first sampling voltage or the second sampling voltage and a first reference voltage, and determines a duty cycle of the second switch tube according to the first sampling current and the first reference current; When the required AC voltage between the first AC terminal and the second AC terminal is a positive half-wave, the control module controls the first rectifier tube and the fourth rectifier tube to be turned on, and the second rectifier tube and the third rectifier tube to be turned off; When the required AC voltage between the first AC terminal and the second AC terminal is a negative half-wave, the control module controls the second rectifier tube and the third rectifier tube to be turned on, and the first rectifier tube and the fourth rectifier tube to be turned off.

[0019] Optionally, the control module includes: a first voltage control loop and a first current control loop, in which the control module determines a first reference current according to a first sampled voltage and a first reference voltage, and determines a duty cycle of the second switch tube according to the first sampled current and the first reference current; The first voltage control loop is configured to perform loop calculation on a result of subtracting the first reference voltage from the first sampled voltage, and output a first loop current, where the first reference current is an absolute value of the first loop current; The first current control loop is used to perform loop calculation on a result of subtracting the first reference current from the first sampling current, and output a duty cycle of the second switch tube.

[0020] Optionally, when the control module determines the first reference current according to the second sampled voltage and the first reference voltage, and determines the duty cycle of the second switch tube according to the first sampled current and the first reference current, the control module includes: a second voltage control loop and a second current control loop; The second voltage control loop is configured to perform loop calculation on a result of subtracting the absolute value of the first reference voltage from the second sampled voltage, and output a first reference current; The second current control loop is used to perform loop calculation on a result of subtracting the first reference current from the first sampling current, and output a duty cycle of the second switch tube.

[0021] Optionally, in the case where the control module determines the duty cycle of the switch tube in the first DC / DC module according to the first sampled voltage, the control module includes: a third voltage control loop; The third voltage control loop is used to perform loop calculation on a result of subtracting the first reference voltage from the first sampling voltage, and output a duty cycle of the second switch tube.

[0022] In an embodiment of the present application, when the control module determines the duty cycle of the switch tube in the first DC / DC module based on the first sampled voltage, the duty cycle of the second switch tube can be determined by a voltage control loop without using a current control loop, thereby reducing the complexity of the control module.

[0023] Optionally, in the case where the control module determines the duty cycle of the switch tube in the first DC / DC module according to the second sampled voltage, the control module includes: a fourth voltage control loop; The fourth voltage control loop is used to perform loop calculation on a result of subtracting the absolute value of the first reference voltage from the second sampling voltage, and output a duty cycle of the second switching tube.

[0024] In an embodiment of the present application, when the control module determines the duty cycle of the switch tube in the first DC / DC module based on the second sampled voltage, the duty cycle of the second switch tube can be determined by a voltage control loop without using a current control loop, thereby reducing the complexity of the control module.

[0025] A second aspect of an embodiment of the present application provides a vehicle, comprising the energy conversion device of the first aspect of the embodiment of the present application and a battery, wherein the energy conversion device is used to convert the direct current of the battery into alternating current to achieve a reverse discharge function.

[0026] The energy conversion device of the present embodiment adopts a single-stage topology. Compared to a two-stage architecture employing a PFC module and a DC / DC module, this reduces the number of active components, thereby reducing the cost and size of the energy conversion device. The control module can determine the duty cycle of the switching transistor in the first DC / DC module based on the first sampled voltage or the second sampled voltage, and control the on / off switching of the rectifier transistor in the rectifier module to achieve the DC-to-AC conversion function of the energy conversion device, thereby enabling the energy conversion device to operate in a reverse discharge mode, expanding the application scenarios of the energy conversion device. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. 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.

[0028] Figure 1 This is a schematic structural diagram of an energy conversion device provided in an embodiment of the present application; Figure 2 This is a structural diagram of a control module in a reverse discharge mode provided by an embodiment of the present application; Figure 3 This is a structural diagram of a control module in another reverse discharge mode provided by an embodiment of the present application; Figure 4 This is a structural diagram of a control module in another reverse discharge mode provided by an embodiment of the present application; Figure 5 This is a structural diagram of a control module in another reverse discharge mode provided by an embodiment of the present application; Figure 6 1 is a schematic diagram of the waveform of the AC voltage output from the first AC terminal and the second AC terminal of an energy conversion device provided in an embodiment of the present application; Figure 7 It is a structural schematic diagram of a vehicle provided in an embodiment of the present application. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0030] The terms "first," "second," and the like in the specification and claims of this application and the accompanying drawings are used to distinguish between different objects, not to describe a particular order. Furthermore, the terms "including," "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements, but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to the process, product, or apparatus.

[0031] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0032] See also Figure 1 , Figure 1 This is a schematic diagram of the structure of an energy conversion device provided in an embodiment of the present application. Figure 1 As shown, the energy conversion device may include a rectifier module 10, at least one DC / DC module and a control module 30. The at least one DC / DC module may include one or more DC / DC modules. Figure 1 It is taken as an example that at least one DC / DC module includes a DC / DC module.

[0033] The first end of the rectifier module 10 is connected to the first AC end (such as Figure 1 AC_L shown in FIG), the second end of the rectifier module 10 is connected to the second AC end (such as Figure 1AC_N shown in the figure), the third end of the rectifier module 10 is connected to the first end of the first DC / DC module 21, the fourth end of the rectifier module 10 is connected to the second end of the first DC / DC module 21, the third end of the first DC / DC module 21 is connected to the first DC end, and the fourth end of the first DC / DC module 21 is connected to the second DC end; the first DC / DC module 21 is any one of the at least one DC-to-DC converter DC / DC module; When the energy conversion device operates in the reverse discharge mode, the control module 30 generates a voltage signal according to the first sampling voltage (e.g. Figure 1 The V ac ) or the second sampling voltage (such as Figure 1 The V rec ) determines the duty cycle of the switch tube in the first DC / DC module 21, controls the on or off of the rectifier tube in the rectifier module 10, so as to realize the DC-to-AC function of the energy conversion device; the first sampling voltage is the sampling voltage between the first end of the rectifier module 10 and the second end of the rectifier module 10, and the second sampling voltage is the sampling voltage between the first end of the first DC / DC module 21 and the second end of the first DC / DC module 21.

[0034] In one possible embodiment, the energy conversion device can implement an alternating current / direct current (AC / DC) conversion function. 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 a DC output.

[0035] In one possible embodiment, the energy conversion device can convert direct current (DC) into alternating current (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.

[0036] For example, the energy conversion device may be an onboard charger on a vehicle, which may be a bidirectional onboard charger capable of converting AC to DC and DC to AC.

[0037] In the embodiment of the present application, the energy conversion device can operate in a reverse discharge mode and a forward charging mode, which can expand the application scenarios of the energy conversion device.

[0038] When the energy conversion device operates in the reverse discharge mode, the energy conversion device can realize the DC / AC function. The energy conversion device can convert the DC power (such as Figure 1 The V HV ) into AC (such as Figure 1 The V ac ), the AC end is output from the first AC end and the second AC end to the AC load (a load that supports AC power supply), thereby powering the AC load.

[0039] When the energy conversion device operates in forward charging mode, it can realize AC / DC functions. The energy conversion device can convert the AC power at the first AC terminal and the second AC terminal into DC power, and output the DC power from the first DC terminal and the second DC terminal to the positive and negative poles of the battery, thereby charging the battery.

[0040] The rectifier module 10 can perform bidirectional rectification. For example, when the energy conversion device operates in forward charging mode, the rectifier module 10 can convert the AC voltage between the first and second AC terminals into a DC voltage (e.g., a mantou wave, which is a waveform obtained by half-wave rectification and can be a waveform obtained by inverting the negative half-cycle of a sine wave) and output this DC voltage to the first and second terminals of the first DC / DC module 21. When the energy conversion device operates in reverse discharge mode, the rectifier module 10 can also convert the DC voltage between the first and second terminals of the first DC / DC module 21 into an AC voltage and output this AC voltage to the first and second AC terminals.

[0041] The first DC / DC module 21 can convert one DC voltage to another. For example, when the energy conversion device is operating in forward charging mode, the first DC / DC module 21 can convert a pulsating DC waveform (e.g., a steamed bun waveform) between the third and fourth terminals of the rectifier module 10 into a linear DC waveform, and output this linear DC waveform to the first and second DC terminals. When the energy conversion device is operating in reverse discharge mode, the first DC / DC module 21 can also convert the linear DC waveform between the first and second DC terminals into a pulsating DC waveform, and output this pulsating DC waveform to the third and fourth terminals of the rectifier module 10.

[0042] A two-stage architecture of PFC module and DC / DC module is adopted, and electrolytic capacitors (also called bus capacitors) need to be added between the PFC module and the DC / DC module for decoupling.

[0043] In an embodiment of the present application, the energy conversion device adopts a single-stage topology. Compared with a two-stage architecture using 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 add an electrolytic capacitor, which improves the power density of the energy conversion device, thereby 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 based on the first sampled voltage or the second sampled voltage, and control the conduction or shutdown of the rectifier tube in the rectifier module to realize the DC-to-AC function of the energy conversion device, thereby allowing the energy conversion device to operate in a reverse discharge mode, expanding the application scenarios of the energy conversion device.

[0044] At least one DC / DC module is connected in an interleaved parallel manner to increase the output power of the energy conversion device, which can be applied to high-power scenarios.

[0045] like Figure 1 As shown, the first DC / DC module 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, and the second end of the secondary winding is connected to the second end of the third capacitor C3 and the second DC terminal.

[0046] like Figure 1 As shown, the diode connected in parallel between the first terminal of the first switch transistor S1 and the second terminal of the first switch transistor S1 is a parasitic diode or a body diode, which can prevent the first switch transistor S1 from being damaged by overvoltage, electrostatic discharge, or other transient voltages. The diode connected in parallel between the first terminal of the second switch transistor S2 and the second terminal of the second switch transistor S2 is a parasitic diode or a body diode, which can prevent the second switch transistor S2 from being damaged by overvoltage, electrostatic discharge, or other transient voltages.

[0047] In this embodiment, the first DC / DC module 21 includes two switching transistors: a first switching transistor S1 and a second switching transistor S2. A conventional single-stage alternating current / direct current (AC / DC) module includes at least two bridge arms (at least four switching transistors). Compared to conventional single-stage AC / DC modules, the first DC / DC module 21 in this embodiment can reduce the number of switching transistors, thereby further reducing the cost and size of the energy conversion device.

[0048] in, Figure 1 i in L1 is the current on the first inductor L1, i L2 is the current on the second inductor L2, i s2 is the current passing through the second switch tube S2.

[0049] The transformer T1 may be an isolation transformer, which 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).

[0050] Optionally, the second inductor L2 is the magnetizing inductor in the primary winding of the transformer T1.

[0051] In the embodiment of the present application, the second inductor L2 can reuse the magnetizing inductance 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.

[0052] like Figure 1 As shown, the rectifier module 10 includes a first rectifier tube Q1, a second rectifier tube Q2, a third rectifier tube Q3 and a fourth rectifier tube Q4. The first end of the first rectifier tube Q1 is connected to the first end of the second rectifier tube Q2 and the first end of the first DC / DC module 21. The second end of the first rectifier tube Q1 is connected to the first end of the third rectifier tube Q3 and the first AC end. The second end of the second rectifier tube Q2 is connected to the first end of the fourth rectifier tube Q4 and the second AC end. The second end of the third rectifier tube Q3 is connected to the second end of the fourth rectifier tube Q4 and the second end of the first DC / DC module 21.

[0053] In the embodiment of the present application, the rectifier module 10 includes four rectifier tubes, and the control module 30 can control the conduction or shutdown of the rectifier tubes in the rectifier module 10. The rectifier tubes are different from simple diodes, so that the rectifier module 10 can support bidirectional rectification, so that the energy conversion device can operate in both 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 the DC power is output from the first DC end and the second DC end to the positive and negative poles of the battery, thereby charging the battery), and reverse discharge mode (the energy conversion device can convert the DC power at 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 the AC load (a load that supports AC power supply), thereby powering the AC load), which expands the application scenarios of the energy conversion device.

[0054] Optionally, each rectifier tube includes an insulated-gate bipolar transistor (IGBT) or a metal-oxide-semiconductor field-effect transistor (MOSFET).

[0055] In the embodiment of the present application, MOSFET may also be referred to as MOS tube or MOS transistor. The rectifier tube may be an IGBT or a MOS tube. Using an IGBT for the rectifier tube can reduce costs, while using a MOS tube for the rectifier tube can reduce conduction loss.

[0056] Optionally, both the first switch tube S1 and the second switch tube S2 may be IGBTs or MOSFETs.

[0057] Figure 1 The rectifier tubes are all IGBT as an example. Figure 1 The first switch S1 and the second switch S2 are both N-type MOS transistors. N-type MOS transistors can be referred to as NMOS transistors. MOSFETs can be silicon carbide (SiC) MOSFETs or gallium nitride (GaN) MOSFETs. SiC MOSFETs are MOSFETs made of silicon carbide, while GaN MOSFETs are MOSFETs made of gallium nitride.

[0058] A diode may be connected in parallel between the first and second ends of each rectifier. The first end of the first rectifier Q1 is connected to the cathode of the diode connected in parallel with the first rectifier Q1, and the second end of the first rectifier Q1 is connected to the anode of the diode connected in parallel with the first rectifier Q1. The first end of the second rectifier Q2 is connected to the cathode of the diode connected in parallel with the second rectifier Q2, and the second end of the second rectifier Q2 is connected to the anode of the diode connected in parallel with the second rectifier Q2. The first end of the third rectifier Q3 is connected to the cathode of the diode connected in parallel with the third rectifier Q3, and the second end of the third rectifier Q3 is connected to the anode of the diode connected in parallel with the third rectifier Q3. The first end of the fourth rectifier Q4 is connected to the cathode of the diode connected in parallel with the fourth rectifier Q4, and the second end of the fourth rectifier Q4 is connected to the anode of the diode connected in parallel with the fourth rectifier Q4.

[0059] The diode connected in parallel with each rectifier tube can be the body diode or parasitic diode of the rectifier tube. The diode can play the role of freewheeling.

[0060] 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 or the second sampled voltage, and controls the on or off of the rectifier tube in the rectifier module 10 to realize the DC-to-AC function of the energy conversion device, including: 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 or the second sampled voltage and the first sampled current, and controls the on or off of the rectifier tube in the rectifier module 10 to achieve the DC-to-AC function of the energy conversion device. The first sampled current is the current on the first inductor L1.

[0061] In this embodiment of the present application, the first sampled voltage is the sampled voltage output by the energy conversion device when operating in reverse discharge mode. The control module 30 can adjust the output voltage of the energy conversion device based on the sampled voltage output by the energy conversion device when operating in reverse discharge mode, thereby ensuring the stability of the output voltage of the energy conversion device. The first sampled current is the sampled current of the first inductor L1. Because the current of the first inductor L1 varies with the load at the output end (the first AC end and the second AC end) of the energy conversion device, the control module 30 can adjust the current of the first inductor L1 based on the sampled current of the first inductor L1, thereby improving the dynamic characteristics of the load at the output end of the energy conversion device and providing current limiting. When the energy conversion device operates in reverse discharge mode, the sampled current of the first inductor L1 is the sampled current output by the energy conversion device. The control module 30 determines the duty cycle of the switching transistor in the first DC / DC module 21 based on the first sampled voltage or the second sampled voltage and the first sampled current, thereby ensuring the stability of the output voltage and current of the energy conversion device when the energy conversion device operates in reverse discharge mode.

[0062] 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 or the second sampled voltage and the first sampled current, and controls the on or off of the rectifier tube in the rectifier module 10 to realize the DC-to-AC function of the energy conversion device, including: The control module 30 determines a first reference current according to the first sampling voltage or the second sampling voltage and the first reference voltage, and determines a duty cycle of the second switch tube S2 according to the first sampling current and the first reference current; When the required AC voltage between the first AC terminal and the second AC terminal is a positive half-wave, the control module 30 controls the first rectifier tube Q1 and the fourth rectifier tube Q4 to be turned on, and the second rectifier tube Q2 and the third rectifier tube Q3 to be turned off; When the required AC voltage between the first AC terminal and the second AC terminal is a negative half-wave, the control module 30 controls the second rectifier tube Q2 and the third rectifier tube Q3 to be turned on, and the first rectifier tube Q1 and the fourth rectifier tube Q4 to be turned off.

[0063] In the embodiment of the present application, the first reference voltage is the instantaneous value of the required AC voltage currently set by the energy conversion device (the AC voltage to be output between the first AC terminal and the second AC terminal), and the first sampled voltage is the voltage obtained by sampling the first terminal of the rectifier module 10 and the second terminal of the rectifier module 10 through the voltage sampling module, such as Figure 1 The V ac The first sampling current may be the sampling current on the first inductor L1, such as Figure 1 The i shown L1 The second sampling voltage may be a sampling voltage between the first terminal of the first DC / DC module 21 and the second terminal of the first DC / DC module 21, such as Figure 1 The V rec .

[0064] The duty cycle of the second switch S2 can be used to adjust the amplitude of the voltage between the first AC terminal and the second AC terminal. For example, when the first sampling voltage is greater than the first reference voltage, the duty cycle of the second switch S2 can be reduced, thereby reducing the voltage across the first capacitor C1 (e.g. Figure 1 The V rec ), thereby reducing the amplitude of the voltage between the first AC terminal and the second AC terminal, so that the amplitude of the voltage between the first AC terminal and the second AC terminal is close to or equal to the first reference voltage. When the first sampled voltage is less than the first reference voltage, the duty cycle of the second switch S2 can be increased, thereby increasing the voltage across the first capacitor C1, and thereby increasing the amplitude of the voltage between the first AC terminal and the second AC terminal, so that the amplitude of the voltage between the first AC terminal and the second AC terminal is close to or equal to the first reference voltage.

[0065] The period of the AC voltage required between the first AC terminal and the second AC terminal can be set as needed. For example, the period of the AC voltage required is 20 milliseconds (50 Hz), the amplitude of the AC voltage required is 311V, and the effective value of the AC voltage required is 220V.

[0066] The control module 30 can control the conduction duration (e.g., 10 milliseconds) of the first rectifier Q1 and the fourth rectifier Q4 so that the positive half-wave of the required AC voltage occurs between the first AC terminal and the second AC terminal. The control module 30 can control the conduction duration (e.g., 10 milliseconds) of the second rectifier Q2 and the third rectifier Q3 so that the negative half-wave of the required AC voltage occurs between the first AC terminal and the second AC terminal.

[0067] See also Figure 2 , Figure 2 This is a schematic diagram of the structure of a control module in a reverse discharge mode provided by an embodiment of the present application. Figure 2 As shown, when the control module 30 determines the first reference current according to the first sampling voltage and the first reference voltage, and determines the duty cycle of the second switch tube S2 according to the first sampling current and the first reference current, the control module 30 includes a first voltage control loop and a first current control loop.

[0068] In the embodiment of the present application, the first voltage control loop is used to control the first reference voltage (such as Figure 2 The V ac_Ref) and the first sampling voltage (such as Figure 2 The V ac ) performs loop calculation on the result after subtraction, and outputs the first loop current. The first reference current (such as Figure 2 The i shown L1_Ref ) is the absolute value of the first loop current. The regulator in the first voltage control loop can be a proportional integral (PI) regulator or a proportional resonant (PR) regulator, which is used to adjust (V ac_Ref -V ac ) to perform loop calculation and obtain the first loop current. Figure 2 In the example, the regulator in the first voltage control loop is a PI regulator. Abs is an absolute value module used to take the absolute value of the first loop current to obtain the first reference current (such as Figure 2 The i shown L1_Ref ).

[0069] The first current control loop is used to control the first reference current and the first sampling current (such as Figure 2 The i shown L1 ) is subtracted and the result is looped to calculate and output the duty cycle of the second switch tube S2 (such as Figure 2 The regulator in the first current control loop may be a proportional integral (PI) regulator or a proportional resonant (PR) regulator, which is used to control (i L1_Ref -i L1 ) performs loop calculation to obtain the duty cycle d2 of the second switch tube S2. Figure 2 In the embodiment, the regulator in the first current control loop is exemplified by a PI regulator.

[0070] In the embodiment of the present application, the first voltage control loop is a voltage outer loop, and the first current control loop is a current inner loop.

[0071] Figure 2 The wave driving module in the embodiment can be a pulse width modulation (PWM) module. The 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 second switch tube S2, 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 2As 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.

[0072] See also Figure 3 , Figure 3 This is a schematic diagram of the structure of another control module in a reverse discharge mode provided by an embodiment of the present application. When the control module 30 determines a first reference current based on a second sampled voltage and a first reference voltage, and determines a duty cycle of the second switch S2 based on the first sampled current and the first reference current, the control module includes: a second voltage control loop and a second current control loop; The second voltage control loop is configured to perform loop calculation on a result of subtracting the absolute value of the first reference voltage from the second sampled voltage, and output a first reference current; The second current control loop is used to perform loop calculation on a result of subtracting the first reference current from the first sampling current, and output a duty cycle of the second switch tube.

[0073] In the embodiment of the present application, the second voltage control loop is used to control the first reference voltage (such as Figure 3 The V ac_Ref ) takes its absolute value, and the second sampling voltage (such as Figure 3 The V rec ) is subtracted and the result is looped and the first reference current is output (e.g. Figure 3 The i shown L1_Ref The regulator in the second voltage control loop can be a proportional integral (PI) regulator or a proportional resonant (PR) regulator, which is used to adjust (V ac_Ref Absolute value of -V rec ) performs loop calculation to obtain the first reference current. Figure 3 In the embodiment, the regulator in the second voltage control loop is a PI regulator. Abs is an absolute value module, which is used to obtain the absolute value of the first reference voltage.

[0074] The second current control loop is used to control the first reference current and the first sampling current (such as Figure 3 The i shown L1 ) is subtracted and the result is looped to calculate and output the duty cycle of the second switch tube S2 (such as Figure 3The regulator in the second current control loop may be a proportional integral (PI) regulator or a proportional resonant (PR) regulator, which is used to control (i L1_Ref -i L1 ) performs loop calculation to obtain the duty cycle d2 of the second switch tube S2. Figure 3 In the embodiment, the regulator in the second current control loop is exemplified by a PI regulator.

[0075] In the embodiment of the present application, the second voltage control loop is a voltage outer loop, and the second current control loop is a current inner loop.

[0076] See also Figure 4 , Figure 4 This is a structural diagram of a control module in another reverse discharge mode provided by an embodiment of the present application. Figure 4 As shown, in the case where the control module 30 determines the duty cycle of the switch tube in the first DC / DC module according to the first sampled voltage, the control module 30 includes a third voltage control loop.

[0077] In the embodiment of the present application, the third voltage control loop is used to control the first reference voltage (such as Figure 4 The V ac_Ref ) and the first sampling voltage (such as Figure 4 The V ac ) is subtracted and the result is looped to calculate and output the duty cycle of the second switch tube S2 (such as Figure 4 d2 shown).

[0078] Figure 4 The wave driving module in the embodiment can be a PWM module. The 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 second switch tube S2, 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 4 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.

[0079] In the embodiment of the present application, the duty cycle of the second switch tube S2 can be determined by a voltage control loop without using a current control loop, thereby reducing the complexity of the control module 30.

[0080] See also Figure 5 , Figure 5 This is a structural diagram of a control module in another reverse discharge mode provided by an embodiment of the present application. Figure 5 As shown, in the case where the control module determines the duty cycle of the switch tube in the first DC / DC module according to the second sampled voltage, the control module 30 includes a fourth voltage control loop.

[0081] In the embodiment of the present application, the fourth voltage control loop is used to control the first reference voltage (such as Figure 5 The V ac_Ref ) and the absolute value of the second sampling voltage (such as Figure 5 The V rec ) is subtracted and the result is looped to calculate and output the duty cycle of the second switch tube S2 (such as Figure 5 d2 shown).

[0082] Figure 5 The wave driving module in the embodiment can be a PWM module. The 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 second switch tube S2, 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 5 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.

[0083] In the embodiment of the present application, the duty cycle of the second switch tube S2 can be determined by a voltage control loop without using a current control loop, thereby reducing the complexity of the control module 30.

[0084] See also Figure 6 , Figure 6 Schematic diagram of the waveform of the AC voltage outputted from the first AC terminal and the second AC terminal of an energy conversion device provided in an embodiment of the present application. Figure 6 As shown, the inverted AC voltage is the AC voltage output by the first AC terminal and the second AC terminal of the energy conversion device. The amplitude of the AC voltage is 311V and the frequency of the AC voltage is 50Hz.

[0085] See also Figure 7 , Figure 7 This is a schematic diagram of the structure of a vehicle provided in an embodiment of the present application. Figure 7 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 AC power into DC power to charge battery 200. Battery 200 may input DC power into energy conversion device 100, which then converts the input DC power into AC power to power an AC load.

[0086] Figure 7 The specific structure and working principle of the energy conversion device 100 can be found in the above Figures 1 to 5 The embodiments shown are not described in detail here.

[0087] 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.

[0088] 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 in that: The device comprises a rectifier module, at least one DC / DC converter module and a control module, wherein a first end of the rectifier module is connected to a first AC end, a second end of the rectifier module is connected to a second AC 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 DC end, and a fourth end of the first DC / DC module is connected to a second DC end; the first DC / DC module is any one of the at least one DC / DC converter module; When the energy conversion device operates in the reverse discharge mode, the control module determines the duty cycle of the switching tube in the first DC / DC module according to the first sampled voltage or the second sampled voltage, and controls the on or off of the rectifier tube in the rectifier module to achieve the DC-to-AC function of the energy conversion device; the first sampled voltage is the sampled voltage between the first end and the second end of the rectifier module, and the second sampled voltage is the sampled voltage between the first end and the second end of the first DC / DC module.

2. The energy conversion device according to claim 1, characterized in that The first DC / DC module includes: a first capacitor, a second capacitor, a third capacitor, a first switching tube, a second switching tube, a first inductor, a second inductor and a transformer; the first end of the first capacitor is connected to the first end of the first inductor and the third end of the rectifier module, the second end of the first inductor is connected to the first end of the second capacitor and the first end of the first switching tube, the second end of the second capacitor is connected to the first end of the second inductor and the first end of the primary winding of the transformer, the second end of the first capacitor is connected to the second end of the first switching tube, the second end of the second inductor, the second end of the primary winding and the fourth end of the rectifier module; the first end of the secondary winding of the transformer is connected to the first end of the second switching tube, the second end of the second switching tube is connected to the first end of the third capacitor and the first DC terminal, and the second end of the secondary winding is connected to the second end of the third capacitor and the second DC terminal.

3. The energy conversion device according to claim 2, characterized in that: The rectifier module includes a first rectifier tube, a second rectifier tube, a third rectifier tube and a fourth rectifier tube. The first end of the first rectifier tube is connected to the first end of the second rectifier tube and the first end of the first DC / DC module, the second end of the first rectifier tube is connected to the first end of the third rectifier tube and the first AC end, the second end of the second rectifier tube is connected to the first end of the fourth rectifier tube and the second AC end, and the second end of the third rectifier tube is connected to the second end of the fourth rectifier tube and the second end of the first DC / DC module.

4. The energy conversion device according to claim 3, characterized in that: The control module determines the duty cycle of the switch tube in the first DC / DC module according to the first sampled voltage or the second sampled voltage, and controls the on or off of the rectifier tube in the rectifier module to realize the DC-to-AC function of the energy conversion device, including: The control module determines the duty cycle of the switch tube in the first DC / DC module based on the first sampled voltage or the second sampled voltage and the first sampled current, and controls the on or off of the rectifier tube in the rectifier module to achieve the DC-to-AC function of the energy conversion device, where the first sampled current is the current on the first inductor.

5. The energy conversion device according to claim 4, characterized in that: The control module determines the duty cycle of the switch tube in the first DC / DC module according to the first sampled voltage or the second sampled voltage and the first sampled current, and controls the on or off of the rectifier tube in the rectifier module to realize the DC-to-AC function of the energy conversion device, including: The control module determines a first reference current according to the first sampling voltage or the second sampling voltage and a first reference voltage, and determines a duty cycle of the second switch tube according to the first sampling current and the first reference current; When the required AC voltage between the first AC terminal and the second AC terminal is a positive half-wave, the control module controls the first rectifier tube and the fourth rectifier tube to be turned on, and the second rectifier tube and the third rectifier tube to be turned off; When the required AC voltage between the first AC terminal and the second AC terminal is a negative half-wave, the control module controls the second rectifier tube and the third rectifier tube to be turned on, and the first rectifier tube and the fourth rectifier tube to be turned off.

6. The energy conversion device according to claim 5, characterized in that: In the case where the control module determines the first reference current according to the first sampled voltage and the first reference voltage, and determines the duty cycle of the second switch tube according to the first sampled current and the first reference current, the control module includes: a first voltage control loop and a first current control loop; The first voltage control loop is configured to perform loop calculation on a result of subtracting the first reference voltage from the first sampled voltage, and output a first loop current, where the first reference current is an absolute value of the first loop current; The first current control loop is used to perform loop calculation on a result of subtracting the first reference current from the first sampling current, and output a duty cycle of the second switch tube.

7. The energy conversion device according to claim 5, characterized in that: In the case where the control module determines the first reference current according to the second sampled voltage and the first reference voltage, and determines the duty cycle of the second switch tube according to the first sampled current and the first reference current, the control module includes: a second voltage control loop and a second current control loop; The second voltage control loop is configured to perform loop calculation on a result of subtracting the absolute value of the first reference voltage from the second sampled voltage, and output a first reference current; The second current control loop is used to perform loop calculation on a result of subtracting the first reference current from the first sampling current, and output a duty cycle of the second switch tube.

8. The energy conversion device according to claim 5, characterized in that: In the case where the control module determines the duty cycle of the switch tube in the first DC / DC module according to the first sampled voltage, the control module includes: a third voltage control loop; The third voltage control loop is used to perform loop calculation on a result of subtracting the first reference voltage from the first sampling voltage, and output a duty cycle of the second switch tube.

9. The energy conversion device according to claim 5, characterized in that: In the case where the control module determines the duty cycle of the switch tube in the first DC / DC module according to the second sampled voltage, the control module includes: a fourth voltage control loop; The fourth voltage control loop is used to perform loop calculation on a result of subtracting the absolute value of the first reference voltage from the second sampling voltage, and output a duty cycle of the second switch tube.

10. A vehicle, characterized in that: The device 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 the direct current of the battery into alternating current to achieve a reverse discharge function.

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