Charging module and system of electric vehicle based on hybrid power processing

Abstract

The invention discloses an electric vehicle charging module and system based on hybrid power processing, the charging module comprises a first AC-DC converter and a hybrid power processing unit, the hybrid power processing unit is an isolated DC-DC converter structure and comprises an isolation transformer, at least one first Si power processing module and at least one second SiC power processing module, the first Si power processing module and the second SiC power processing module are connected in parallel between a direct current output port of the first AC-DC converter and the primary side of the isolation transformer, an alternating current input port of the first AC-DC converter is connected with an alternating current power supply, and an alternating current output port of the second AC-DC converter is connected with a direct current output port of the isolation transformer. The DC output ports of the first AC-DC converter and the second AC-DC converter are connected with a device to be charged. The problem that efficiency, cost, electric energy quality and reliability of the charging pile cannot be considered at the same time is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of electric vehicle charging, and in particular to a charging module and system for an electric vehicle based on hybrid power processing. Background Art

[0002] As an energy replenishment device, the charging system is a key infrastructure for the large-scale promotion and application of new energy vehicles. Electric vehicle charging systems are constantly evolving and are of various types, mainly including two types of solutions: AC slow charging and high-power DC fast charging. At present, high-power and high-voltage supercharging technology can effectively solve the problem of charging speed. The high-power charging technology architecture of electric vehicles can be divided into three categories: fixed power type based on traditional power frequency transformers, fixed power type based on power electronic transformers, and charging pile type based on power sharing. When the output power of the fixed power architecture charger is designed to be large, charging electric vehicles with small energy storage capacity will cause a waste of charging capacity and a low utilization rate of the charger; if the output power of the charger is designed to be small, although the utilization rate of the charger can be improved, when charging electric vehicles with large energy storage capacity, the charging time is extended, which brings inconvenience to the owner. With the rapid development of power battery technology, the charging pile charging technology architecture based on power sharing has a good development prospect.

[0003] The existing charging stack type based on power sharing includes charging stack full power processing and charging stack partial power processing. However, the traditional charging stack full power processing technology solution, such as the patent with publication number CN116494790A, has low efficiency and poor power quality. The full power processing solution using SiC devices has high cost and low power level; the charging stack partial power processing technology solution also has the problems of poor power quality, low efficiency, complex circuit structure and poor reliability. In short, the existing technical solutions cannot achieve the comprehensive optimization of efficiency, cost, power quality and reliability. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] Based on the above problems, the present invention provides a charging module and system for an electric vehicle based on hybrid power processing, which solves the problem that the efficiency, cost, power quality and reliability of the charging stack cannot be taken into account at the same time.

[0006] (II) Technical solution

[0007] Based on the above technical problems, the present invention provides a charging module for an electric vehicle based on hybrid power processing, including a first AC-DC converter and a hybrid power processing unit, wherein the hybrid power processing unit is an isolated DC-DC converter structure, including an isolation transformer, at least one first Si power processing module, at least one second SiC power processing module, and a second AC-DC converter located on the secondary side of the isolation transformer, wherein the first Si power processing module and the second SiC power processing module are connected in parallel between the DC output port of the first AC-DC converter and the primary side of the isolation transformer, the AC input port of the first AC-DC converter is connected to an AC power supply, and the DC output port of the first AC-DC converter and the DC output port of the second AC-DC converter constitute the DC output port of the hybrid power processing unit and are connected to a device to be charged.

[0008] Furthermore, the first AC-DC converter adopts an H-bridge converter, including four first-type power switches connected in H-type, and the first-type power switches are Si-based devices; the first Si power processing module adopts an H-bridge DC-AC converter, including four second-type power switches connected in H-type, and the second-type power switches are Si-based devices; the second SiC power processing module adopts an H-bridge DC-AC converter, including four third-type power switches connected in H-type, and the third-type power switches are SiC-based devices; the second AC-DC converter adopts an H-bridge converter, including four fourth-type power switches connected in H-type; the DC output port of the first AC-DC converter is connected to the DC input port of the first Si power processing module and the second SiC power processing module, the AC output ports of the first Si power processing module and the second SiC power processing module are both connected to the primary side of the isolation transformer, the secondary side of the isolation transformer is connected to the AC input port of the second AC-DC converter, and the DC output ports of the first AC-DC converter and the second AC-DC converter constitute the DC output port of the hybrid power processing unit and are connected to the device to be charged.

[0009] Furthermore, the first AC-DC converter includes four first-type power switches Q connected in H-type. Ai1 , Q Ai2 , Q Ai3 , Q Ai4 , Q Ai1 The first end and Q Ai2 The second end of the series connection, Q Ai1 With Q Ai2 The first AC input port on the AC side is provided between Ai3 The first end and Q Ai4 The second end of the series connection, Q Ai3 With Q Ai4There is a second AC input port on the AC side, Q Ai1 The second end and Q Ai3 The second end of the DC output port is connected in series and connected to the first DC output port of the DC side, Q Ai2 The first end and Q Ai4 The first end of Q is connected in series and connected to the second DC output port on the DC side, the first DC output port is connected to the first DC input port of the first Si power processing module, the third DC input port of the second SiC power processing module and the positive electrode of the unit to be charged, and the second DC output port is connected to the second DC input port of the first Si power processing module, the fourth DC input port of the second SiC power processing module and the negative electrode of the unit to be charged; wherein, Q Ai1 , Q Ai2 , Q Ai3 , Q Ai4 The first end is the emitter and the second end is the collector.

[0010] Furthermore, the first Si power processing module includes four second-type power switches S connected in H-type. Ai1 , S Ai2 , S Ai3 , S Ai4 , each second type power switch is connected in parallel with a corresponding capacitor; S Ai1 The second end and S Ai3 The second end of S is connected in series and connected to the first DC input port, the first DC input port is connected to the first DC output port, Ai2 The first end and S Ai4 The first end of S is connected in series and connected to the second DC input port, and the second DC input port is connected to the second DC output port, Ai1 The first end and S Ai2 The second end of the series connection, S Ai1 With S Ai2 A first AC output port is provided between Ai3 The first end and S Ai4 The second end of the series connection, S Ai3 With S Ai4 A second AC output port is provided between the first AC output port and the second AC output port, and the primary side of the isolation transformer is connected between the first AC output port and the second AC output port, wherein S Ai1 , S Ai2 , S Ai3 , S Ai4 The first end is the emitter and the second end is the collector.

[0011] Furthermore, the second SiC power processing module includes four third-type power switches T connected in H-type. Ai1 、T Ai2 、T Ai3 、TAi4 , each third type power switch is connected in parallel with a corresponding capacitor; T Ai1 The second end of the Ai3 The second end of T is connected in series and connected to the third DC input port, and the third DC input port is connected to the first DC output port. Ai2 The first end and T Ai4 The first end of T is connected in series and connected to the fourth DC input port, and the fourth DC input port is connected to the first DC output port, Ai1 The first end and T Ai2 The second end of the series connection, T Ai1 With T Ai2 There is a third power AC port between T Ai3 The first end and T Ai4 The second end of the series connection, T Ai3 With T Ai4 A fourth AC output port is provided between the third AC output port and the fourth AC output port, and the primary side of the isolation transformer is connected between the third AC output port and the fourth AC output port, wherein T Ai1 , T Ai2 , T Ai3 , T Ai4 The first end is the source, and the second end is the drain.

[0012] Furthermore, the structures adopted by the first Si power processing module, the isolation transformer and the second AC-DC converter include a DAB converter, an LLC resonant converter, a phase-shifted full-bridge converter and a CLLC resonant converter, and the structures adopted by the second SiC power processing module, the isolation transformer and the second AC-DC converter include a DAB converter, an LLC resonant converter, a phase-shifted full-bridge converter and a CLLC resonant converter.

[0013] Furthermore, when a DAB converter is used, the second AC-DC converter includes four fourth-type power switches connected in an H-type manner, wherein the fourth-type power switches are IGBTs; an inductor L is connected in series between two AC output ports of the first Si power processing module or the second SiC power processing module. ri The inductor corresponding to the primary side of the isolation transformer.

[0014] Furthermore, when an LLC resonant converter is used, the second AC-DC converter includes four fourth-type power switches connected in an H-type manner, wherein the fourth-type power switches are IGBTs; a capacitor C is connected in series between two AC output ports of the first Si power processing module or the second SiC power processing module. ri 、Inductance L ri The inductor corresponding to the primary side of the isolation transformer.

[0015] Further, when a phase-shifted full-bridge converter is used, the second AC-DC converter includes four fourth-type power switches connected in an H-type manner, wherein the fourth-type power switches are diodes; a capacitor C is connected in series between two AC output ports of the first Si power processing module or the second SiC power processing module. ri 、Inductance L ri The inductor corresponding to the primary side of the isolation transformer.

[0016] The present invention also discloses a charging system for an electric vehicle based on hybrid power processing, comprising a three-phase cascaded multi-port AC-DC converter, a power distribution unit and an electric vehicle charging gun connected in sequence, wherein the three-phase cascaded multi-port AC-DC converter comprises N independent cascaded output ports and a charging module for an electric vehicle based on hybrid power processing as described in any one of claims 1 to 9, wherein in the charging module, the DC input port of the i-th hybrid power processing unit of phase A / phase B / phase C is connected to the DC output port of the i-th first AC-DC converter of the corresponding phase, and the DC output port of the i-th hybrid power processing unit of phase A is connected to the DC output port of the i-th hybrid power processing unit of phase B and the DC output port of the i-th hybrid power processing unit of phase C, together forming port i, 1≤i≤N; the AC input port of the three-phase cascaded multi-port AC-DC converter is directly connected to the medium-voltage power grid for power distribution.

[0017] (III) Beneficial effects

[0018] The above technical solution of the present invention has the following advantages:

[0019] (1) The present invention connects the first Si power processing module and the second SiC power processing module in parallel at the DC output end of the first AC-DC converter, and the output end of the first AC-DC converter and the output end of the second AC-DC converter are both connected to the device to be charged, so that the transmission power flow of the present invention is divided into three parts: direct power flow, main power flow and auxiliary power flow. The direct power flow is directly output to the device to be charged, with minimal loss and improved efficiency; the main power flow is processed at a low frequency by a high-power and low-cost Si main power processing unit, so that the output waveform of the main power is roughly close to the expected output value, and the system switching loss is reduced to improve the charging efficiency. Energy efficiency: The auxiliary power flow uses the high frequency and low loss advantages of the second SiC power processing module to perform high-frequency modulation, modulate a smaller power packet, compensate for the high output ripple caused by the low-frequency operation of the first Si power processing module, and give full play to the advantages of the hybrid power processing unit of Si combined with SiC in different frequency interleaving regulation, suppress the output current ripple of the charging stack, and improve the quality of charging power for electric vehicles, which helps to ensure the long operating life of electric vehicle batteries and ensure the high power conversion efficiency of the system. The hybrid power processing unit takes into account the advantages of Si-based devices and SiC-based devices, thereby achieving the comprehensive optimization of charging stack performance and cost;

[0020] (2) The hybrid power processing unit of the present invention is a parallel structure, that is, the DC output end of the first AC-DC converter is connected in parallel with the first Si power processing module and the second SiC power processing module, and the output end of the first AC-DC converter and the output end of the second AC-DC converter are both connected to the device to be charged. The three power output modes have good redundant fault tolerance and high reliability.

[0021] (3) The hybrid power processing unit of the present invention has four different configurations, which respectively focus on low-cost small and medium power applications, low-cost high-power applications, high-efficiency applications with high power quality, and high-power applications with high power quality. Users can select the most suitable hybrid power processing unit configuration according to different needs and configuration characteristics, and it has a wide applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The features and advantages of the present invention will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the present invention in any way. In the accompanying drawings:

[0023] Figure 1 It is an overall principle diagram of a charging system for an electric vehicle based on hybrid power processing according to an embodiment of the present invention;

[0024] Figure 2 A schematic diagram of the topological structure of a charging system for an electric vehicle based on hybrid power processing according to an embodiment of the present invention;

[0025] Figure 3 The first form of the charging module for electric vehicles based on hybrid power processing according to an embodiment of the present invention;

[0026] Figure 4 The second form of the charging module for electric vehicles based on hybrid power processing according to the embodiment of the present invention;

[0027] Figure 5 The third form of the charging module for electric vehicles based on hybrid power processing according to the embodiment of the present invention;

[0028] Figure 6 A schematic diagram of power flow comparison of a charging module of an electric vehicle based on hybrid power processing according to an embodiment of the present invention;

[0029] Figure 7 A schematic diagram of power processing of a hybrid power processing unit according to an embodiment of the present invention;

[0030] Figure 8 Schematic diagrams of four configurations of a hybrid power processing unit according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0032] Embodiment 1 of the present invention is a charging system for an electric vehicle based on hybrid power processing, such as Figure 1-2 As shown, it includes: a three-phase cascaded multi-port AC-DC converter, a power distribution unit and an electric vehicle charging gun connected in sequence. The three-phase cascaded multi-port AC-DC converter includes a charging module with N independent cascaded output ports, the charging module includes a first AC-DC converter and a hybrid power processing unit, the hybrid power processing unit is an isolated DC-DC converter structure, including an isolation transformer, at least one first Si power processing module, at least one second SiC power processing module, and a second AC-DC converter located on the secondary side of the isolation transformer, the first Si power processing module and the second SiC power processing module are both DC-AC converter structures, the first Si power processing module and the second SiC power processing module are connected in parallel between the DC output port of the first AC-DC converter and the primary side of the isolation transformer, the AC input port of the first AC-DC converter is connected to an AC power supply, the DC output port of the first AC-DC converter and the DC output port of the second AC-DC converter constitute the DC output port of the hybrid power processing unit, and are connected to the device to be charged. The first AC-DC converter is used to convert the input AC power into DC power, and can directly output the converted DC power to the device to be charged, that is, the electric vehicle charging gun, and also output it to the first Si power processing module and the second SiC power processing module. The converted DC power is converted into AC power through power regulation of the first Si power processing module and the second SiC power processing module, and then transformed by the isolation transformer. The transformed AC power is converted into DC power through the second AC-DC converter, and after distribution by the power distribution unit, it is also output to the electric vehicle charging gun.

[0033] The AC input port of the three-phase cascade multi-port AC-DC converter is directly connected to the medium-voltage power grid distribution; the three-phase cascade multi-port AC-DC converter includes a charging module with N independent cascade output ports, in which the DC input port of the i-th hybrid power processing unit of phase A / phase B / phase C is connected to the DC output port of the i-th first AC-DC converter of the corresponding phase, and the DC output port of the i-th hybrid power processing unit of phase A is connected to the DC output port of the i-th hybrid power processing unit of phase B and the DC output port of the i-th hybrid power processing unit of phase C, forming a port i, 1≤i≤N; the power distribution unit includes 2*M*N switching switches; and there are M electric vehicle charging guns. The positive pole of the DC output port of the hybrid power processing unit of each port i is connected to one end of the switching switch in the power distribution unit, and the other end of the switching switch is connected to the positive pole of the electric vehicle charging gun, and the negative pole of the DC output port of the hybrid power processing unit of each port i is connected to one end of the switching switch in the power distribution unit, and the other end of the switching switch is connected to the negative pole of the electric vehicle charging gun. The AC input port of the three-phase cascaded multi-port AC-DC converter connected to the medium voltage distribution network adopts a star connection mode.

[0034] The second embodiment of the present invention is a charging module for an electric vehicle based on hybrid power processing, which is a charging module for any port of any phase in the three-phase cascaded multi-port AC-DC converter of the first embodiment, such as Figure 3 As shown, it includes a first AC-DC converter and a hybrid power processing unit. The hybrid power processing unit is an isolated DC-DC converter structure, including an isolation transformer, at least one first Si power processing module, at least one second SiC power processing module, and a second AC-DC converter located on the secondary side of the isolation transformer. The first Si power processing module and the second SiC power processing module are both DC-AC converter structures. The first Si power processing module and the second SiC power processing module are connected in parallel between the DC output port of the first AC-DC converter and the primary side of the isolation transformer. The AC input port of the first AC-DC converter is connected to an AC power supply. The DC output port of the first AC-DC converter and the DC output port of the second AC-DC converter constitute the DC output port of the hybrid power processing unit and are connected to the device to be charged. The first AC-DC converter is used to convert the input AC power into DC power, and can directly output the converted DC power to the device to be charged, and also output it to the first Si power processing module and the second SiC power processing module. The converted DC power is converted into AC power through power regulation of the first Si power processing module and the second SiC power processing module, and then transformed by the isolation transformer. The transformed AC power is converted into DC power through the second AC-DC converter, and after distribution by the power distribution unit, it is also output to the device to be charged.

[0035] In order to solve the problem of cost and performance synergistic improvement faced by the current AC-DC converter based on a single Si or WBG device, this embodiment gives full play to the advantages of low cost and large capacity of Si-based devices and the advantages of high frequency and low loss of WBG devices, and proposes a hybrid power processing method of Si combined with SiC, in which the first AC-DC converter and the first Si power processing unit are composed of Si-based devices, and the second SiC power processing unit is composed of a third-generation semiconductor device SiC-based device.

[0036] Furthermore, the first AC-DC converter adopts an H-bridge converter, including four first-type power switches connected in H-type, and the first-type power switches are Si-based devices; the first Si power processing module adopts an H-bridge DC-AC converter, including four second-type power switches connected in H-type, and the second-type power switches are Si-based devices; the second SiC power processing module adopts an H-bridge DC-AC converter, including four third-type power switches connected in H-type, and the third-type power switches are SiC-based devices; the second AC-DC converter adopts an H-bridge converter, including four fourth-type power switches connected in H-type; the DC output port of the first AC-DC converter is connected to the DC input port of the first Si power processing module and the second SiC power processing module, the AC output ports of the first Si power processing module and the second SiC power processing module are both connected to the primary side of the isolation transformer, the secondary side of the isolation transformer is connected to the AC input port of the second AC-DC converter, and the DC output ports of the first AC-DC converter and the second AC-DC converter constitute the DC output port of the hybrid power processing unit and are connected to the device to be charged.

[0037] In this embodiment, the first AC-DC converter adopts an H-bridge converter. This embodiment is described by taking the charging module of the i-th port of phase A as an example, including four first-type power switches Q connected in an H-type manner. Ai1 , Q Ai2 , Q Ai3 , Q Ai4 , Q Ai1 The first end and Q Ai2 The second end of the series connection, Q Ai1 With Q Ai2 The first AC input port on the AC side is provided between Ai3 The first end and Q Ai4 The second end of the series connection, Q Ai3 With Q Ai4 There is a second AC input port on the AC side, Q Ai1 The second end and Q Ai3 The second end of the DC output port is connected in series and connected to the first DC output port of the DC side, Q Ai2The first end and Q Ai4 The first end of the first type power switch Q is connected in series and connected to the second DC output port on the DC side, the first DC output port is connected to the first DC input port of the first Si power processing module, the third DC input port of the second SiC power processing module and the positive electrode of the unit to be charged, and the second DC output port is connected to the second DC input port of the first Si power processing module, the fourth DC input port of the second SiC power processing module and the negative electrode of the unit to be charged; wherein the first type power switch Q Ai1 , Q Ai2 , Q Ai3 , Q Ai4 For IGBT, the first type of power switch Q Ai1 , Q Ai2 , Q Ai3 , Q Ai4 The first end is the emitter and the second end is the collector.

[0038] The first type of power switch is the insulated gate bipolar transistor IGBT, which is a Si-based device with large conduction loss and switching loss and low switching speed. It is generally suitable for medium and low frequency application scenarios. The first AC-DC converter uses high-power and low-cost insulated gate bipolar transistors to convert alternating current into direct current and perform low-frequency processing at the same time.

[0039] In this embodiment, a capacitor C is further connected between the first DC output port and the second DC output port. i .

[0040] In this embodiment, the first Si power processing module adopts an H-bridge DC-AC converter, including four second-type power switches connected in H-type, the second-type power switches are Si-based devices, the DC input port of the first Si power processing module is connected to the DC output port of the first AC-DC converter, and the AC output port of the first Si power processing module is connected to the primary side of the isolation transformer; specifically, the first Si power processing module includes four second-type power switches S connected in H-type. Ai1 , S Ai2 , S Ai3 , S Ai4 , each second type power switch is connected in parallel with a corresponding capacitor; S Ai1 The second end and S Ai3 The second end of S is connected in series and connected to the first DC input port, the first DC input port is connected to the first DC output port, Ai2 The first end and S Ai4 The first end of S is connected in series and connected to the second DC input port, and the second DC input port is connected to the second DC output port, Ai1 The first end and S Ai2 The second end of the series connection, SAi1 With S Ai2 A first AC output port is provided between Ai3 The first end and S Ai4 The second end of the series connection, S Ai3 With S Ai4 A second AC output port is provided between the first AC output port and the second AC output port, and a first inductor on the primary side of the isolation transformer is connected between the first AC output port and the second AC output port, wherein the second type power switch S Ai1 , S Ai2 , S Ai3 , S Ai4 IGBT, the second type of power switch S Ai1 , S Ai2 , S Ai3 , S Ai4 The first end is the emitter and the second end is the collector.

[0041] The first Si power processing module uses the second type of power switch for modulation to obtain a current that can be used by the device to be charged; the second type of power switch is an insulated gate bipolar transistor IGBT, which is a Si-based device with large conduction loss and switching loss and low switching speed, and is generally suitable for medium and low frequency application scenarios.

[0042] In this embodiment, the second SiC power processing module adopts an H-bridge DC-AC converter, including four third-type power switches connected in H-type, the third-type power switches are SiC-based devices, the DC input port of the second SiC power processing module is connected to the DC output port of the first AC-DC converter, and the AC output port of the second SiC power processing module is connected to the primary side of the isolation transformer; specifically, the second SiC power processing module includes four third-type power switches T connected in H-type. Ai1 、T Ai2 、T Ai3 、T Ai4 , each third type power switch is connected in parallel with a corresponding capacitor; T Ai1 The second end of the Ai3 The second end of T is connected in series and connected to the third DC input port, and the third DC input port is connected to the first DC output port. Ai2 The first end and T Ai4 The first end of T is connected in series and connected to the fourth DC input port, and the fourth DC input port is connected to the first DC output port, Ai1 The first end and T Ai2 The second end of the series connection, T Ai1 With T Ai2 There is a third power AC port between T Ai3 The first end and T Ai4 The second end of the series connection, TAi3 With T Ai4 A fourth AC output port is provided between the third AC output port and the fourth AC output port, and a second inductor on the primary side of the isolation transformer is connected between the third AC output port and the fourth AC output port, wherein the third type power switch T Ai1 , T Ai2 , T Ai3 , T Ai4 For SiC MOSFET third type power switch T Ai1 , T Ai2 , T Ai3 , T Ai4 The first end is the source, and the second end is the drain.

[0043] The second SiC power processing module utilizes the third type power switch T Ai1 , T Ai2 , T Ai3 , T Ai4 For high-frequency modulation compensation, the third type of power switch is a wide bandgap semiconductor device WBG, which is a type of semiconductor device made of materials with a large bandgap energy band, usually referring to materials such as gallium nitride (GaN) and silicon carbide (SiC), so as to use wide bandgap semiconductor devices for high-frequency modulation compensation. Here, the third type of power switch uses SiC MOSFET, which is a SiC device, referring to a metal oxide semiconductor field effect transistor based on silicon carbide (SiC) material, with lower conduction and switching losses, faster switching speed, and is suitable for high-frequency application scenarios.

[0044] The second AC-DC converter adopts an H-bridge converter, including four fourth-type power switches M connected in H-type. Ai1 、M Ai2 、M Ai3 、M Ai4 , M Ai1 The first end and M Ai2 The second end of the series connection, M Ai1 With M Ai2 There is a third AC input port between M Ai3 The first end and M Ai4 The second end of the series connection, M Ai3 With M Ai4 There is a fourth AC input port between M Ai1 The second end of the Ai3 The second end of the M is connected in series and connected to the third DC output port, M Ai2 The first end and M Ai4 The first end of the first and second ends are connected in series and connected to the fourth DC output port, the third inductor on the secondary side of the isolation transformer is connected between the third AC input port and the fourth AC input port, and the unit to be charged is connected between the third DC output port and the fourth DC output port;

[0045] In this embodiment, the structural form adopted by the first Si power processing module, the isolation transformer and the second AC-DC converter can be any DC-DC converter form, including a DAB converter, an LLC resonant converter, a phase-shifted full-bridge converter and a CLLC resonant converter, etc.; similarly, the structural form adopted by the second SiC power processing module, the isolation transformer and the second AC-DC converter can be any DC-DC converter form, including a DAB converter, an LLC resonant converter, a phase-shifted full-bridge converter and a CLLC resonant converter, etc.; and the DC-DC converter structural form adopted by the first Si power processing module, the isolation transformer and the second AC-DC converter and the DC-DC converter structural form adopted by the second SiC power processing module, the isolation transformer and the second AC-DC converter can be the same or different, and do not affect the selection of the form.

[0046] When using a DAB converter, such as Figure 3 As shown, the second AC-DC converter includes four fourth-type power switches connected in H-type, the fourth-type power switch M Ai1 、M Ai2 、M Ai3 、M Ai4 is an IGBT, the first end is an emitter, and the second end is a collector; an inductor L is connected in series between the two AC output ports of the first Si power processing module or the second SiC power processing module ri The inductor corresponding to the primary side of the isolation transformer, that is, the inductor L connected in series between the first AC output port and the second AC output port of the first Si power processing module ri and the first inductor on the primary side of the isolation transformer, or, an inductor L connected in series between the third AC output port and the fourth AC output port of the second SiC power processing module ri and a second inductor on the primary side of the isolation transformer;

[0047] When the LLC resonant converter is used, Figure 4 As shown, the second AC-DC converter includes four fourth-type power switches connected in H-type, the fourth-type power switch M Ai1 、M Ai2 、M Ai3 、M Ai4 is an IGBT, the first end is an emitter, and the second end is a collector; a capacitor C is connected in series between the two AC output ports of the first Si power processing module or the second SiC power processing module ri 、Inductance L ri The inductor corresponding to the primary side of the isolation transformer, that is, the capacitor C connected in series between the first AC output port and the second AC output port of the first Si power processing module ri 、Inductance Lri and the first inductor on the primary side of the isolation transformer, or a capacitor C connected in series between the third AC output port and the fourth AC output port of the second SiC power processing module. ri 、Inductance L ri and a second inductor on the primary side of the isolation transformer;

[0048] When a phase-shifted full-bridge converter is used, Figure 5 As shown, the second AC-DC converter includes four fourth-type power switches connected in H-type, the fourth-type power switch M Ai1 、M Ai2 、M Ai3 、M Ai4 is a diode, the first end is a positive electrode, and the second end is a negative electrode; a capacitor C is connected in series between the two AC output ports of the first Si power processing module or the second SiC power processing module ri 、Inductance L ri The inductor corresponding to the primary side of the isolation transformer, that is, the capacitor C connected in series between the first AC output port and the second AC output port of the first Si power processing module ri 、Inductance L ri and a first inductor on the primary side of the isolation transformer; a capacitor C connected in series between the third AC output port and the fourth AC output port of the second SiC power processing module ri 、Inductance L ri and a second inductor on the primary side of the isolation transformer.

[0049] In this embodiment, the third DC output port is also connected to a filter circuit, which includes an inductor L fi and capacitor C fi , the third DC output port is connected to the inductor L fi One end of the inductor L fi Connect a capacitor C between the other end and the fourth DC output port fi .

[0050] When the charging module is working normally, the power flow is as follows: Figure 6 As shown in Figure (a), first, the power grid inputs the charging power P 总 Divided into two power flows P 12 The direct power flow P3 is directly output through the charging gun, with the lowest loss and the highest efficiency. The mixed power flow P 12Input hybrid power processing unit. The main power flow P1 of the first AC-DC converter and the first Si power processing module uses high-power and low-cost Si-based devices for low-frequency processing, so that the output waveform of the first Si power processing unit is roughly close to the expected value. The auxiliary power flow P2 of the second SiC power processing module uses the advantages of high frequency and low loss of SiC devices to perform high-frequency modulation on part of the energy flow, modulate smaller energy packets, compensate for the ripple caused by the low-frequency operation of Si-based devices, and realize the role of active hardware filtering. The principle is as follows Figure 7 Compared to Figure 6 The conventional DC-DC module directly handles the full power flow with higher efficiency as shown in (b).

[0051] Further, the hybrid power processing unit includes an isolated DC-DC converter structure, including an isolation transformer, at least one first Si power processing module, at least one second SiC power processing module, and a second AC-DC converter located on the secondary side of the isolation transformer, thus having four configurations, such as Figure 8 As shown. Figure 8 Figure (a) shows a 1:1 configuration of a first Si power processing module and a second SiC power processing module, focusing on low-cost small and medium power applications; Figure 8 Figure (b) shows an X:1 configuration of X first Si power processing modules and 1 second SiC power processing module, focusing on low-cost high-power applications; Figure 8 Figure (c) is a 1:Y configuration of a first Si power processing module and Y second SiC power processing modules, focusing on low ripple (high power quality) and high efficiency applications; Figure 8 Figure (d) is an X:Y configuration of X first Si power processing modules and Y second SiC power processing modules, focusing on low ripple (high power quality) high power applications, X>1, Y>1. Therefore, the most suitable hybrid power processing unit configuration can be selected according to different needs and configuration characteristics.

[0052] In summary, the above-mentioned charging module and system for electric vehicles based on hybrid power processing have the following beneficial effects:

[0053] (1) The present invention connects the first Si power processing module and the second SiC power processing module in parallel at the DC output end of the first AC-DC converter, and the output end of the first AC-DC converter and the output end of the second AC-DC converter are both connected to the device to be charged, so that the transmission power flow of the present invention is divided into three parts: direct power flow, main power flow and auxiliary power flow. The direct power flow is directly output to the device to be charged, with minimal loss and improved efficiency; the main power flow is processed at a low frequency by a high-power and low-cost Si main power processing unit, so that the output waveform of the main power is roughly close to the expected output value, and the system switching loss is reduced to improve the charging efficiency. Energy efficiency: The auxiliary power flow uses the high frequency and low loss advantages of the second SiC power processing module to perform high-frequency modulation, modulate a smaller power packet, compensate for the high output ripple caused by the low-frequency operation of the first Si power processing module, and give full play to the advantages of the hybrid power processing unit of Si combined with SiC in different frequency interleaving regulation, suppress the output current ripple of the charging stack, and improve the quality of charging power for electric vehicles, which helps to ensure the long operating life of electric vehicle batteries and ensure the high power conversion efficiency of the system. The hybrid power processing unit takes into account the advantages of Si-based devices and SiC-based devices, thereby achieving the comprehensive optimization of charging stack performance and cost;

[0054] (2) The hybrid power processing unit of the present invention is a parallel structure, that is, the DC output end of the first AC-DC converter is connected in parallel with the first Si power processing module and the second SiC power processing module, and the output end of the first AC-DC converter and the output end of the second AC-DC converter are both connected to the device to be charged. The three power output modes have good redundant fault tolerance and high reliability.

[0055] (3) The hybrid power processing unit of the present invention has four different configurations, which respectively focus on low-cost small and medium power applications, low-cost high-power applications, high-efficiency applications with high power quality, and high-power applications with high power quality. Users can select the most suitable hybrid power processing unit configuration according to different needs and configuration characteristics, and it has a wide applicability.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the embodiments of the present invention are described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations shall fall within the scope defined by the appended claims.

Claims

1. A charging module for an electric vehicle based on hybrid power processing, characterized in that: It includes a first AC-DC converter and a hybrid power processing unit. The hybrid power processing unit is an isolated DC-DC converter structure, including an isolation transformer, at least one first Si power processing module, at least one second SiC power processing module, and a second AC-DC converter located on the secondary side of the isolation transformer. The first Si power processing module and the second SiC power processing module are both DC-AC converter structures. The first Si power processing module and the second SiC power processing module are connected in parallel between the DC output port of the first AC-DC converter and the primary side of the isolation transformer. The AC input port of the first AC-DC converter is connected to an AC power supply. The DC output port of the first AC-DC converter and the DC output port of the second AC-DC converter constitute the DC output port of the hybrid power processing unit and are connected to a device to be charged.

2. The charging module for electric vehicles based on hybrid power processing according to claim 1, characterized in that: The first AC-DC converter adopts an H-bridge converter, including four first-type power switches connected in H-type, and the first-type power switches are Si-based devices; the first Si power processing module adopts an H-bridge DC-AC converter, including four second-type power switches connected in H-type, and the second-type power switches are Si-based devices; the second SiC power processing module adopts an H-bridge DC-AC converter, including four third-type power switches connected in H-type, and the third-type power switches are SiC-based devices; the second AC-DC converter adopts an H-bridge converter, including four fourth-type power switches connected in H-type; the DC output port of the first AC-DC converter is connected to the DC input port of the first Si power processing module and the second SiC power processing module, the AC output ports of the first Si power processing module and the second SiC power processing module are both connected to the primary side of the isolation transformer, the secondary side of the isolation transformer is connected to the AC input port of the second AC-DC converter, and the DC output ports of the first AC-DC converter and the second AC-DC converter constitute the DC output port of the hybrid power processing unit and are connected to the device to be charged.

3. The charging module for electric vehicles based on hybrid power processing according to claim 1, characterized in that: The first AC-DC converter includes four first-type power switches Q connected in H-type. Ai1 , Q Ai2 , Q Ai3 , Q Ai4 , Q Ai1 The first end and Q Ai2 The second end is connected in series, Q Ai1 With Q Ai2 The first AC input port on the AC side is provided between Ai3 The first end and Q Ai4 The second end of the series connection, Q Ai3 With Q Ai4 There is a second AC input port on the AC side, Q Ai1 The second end and Q Ai3 The second end of the DC output port is connected in series and connected to the first DC output port of the DC side, Q Ai2 The first end and Q Ai4 The first end of Q is connected in series and connected to the second DC output port on the DC side, the first DC output port is connected to the first DC input port of the first Si power processing module, the third DC input port of the second SiC power processing module and the positive electrode of the unit to be charged, and the second DC output port is connected to the second DC input port of the first Si power processing module, the fourth DC input port of the second SiC power processing module and the negative electrode of the unit to be charged; wherein, Q Ai1 , Q Ai2 , Q Ai3 , Q Ai4 The first end is the emitter and the second end is the collector.

4. The charging module for electric vehicles based on hybrid power processing according to claim 1, characterized in that: The first Si power processing module includes four second-type power switches S connected in H-type Ai1 , S Ai2 , S Ai3 , S Ai4 , each second type power switch is connected in parallel with a corresponding capacitor; S Ai1 The second end and S Ai3 The second end of S is connected in series and connected to the first DC input port, the first DC input port is connected to the first DC output port, Ai2 The first end and S Ai4 The first end of S is connected in series and connected to the second DC input port, and the second DC input port is connected to the second DC output port, Ai1 The first end and S Ai2 The second end of the series connection, S Ai1 With S Ai2 A first AC output port is provided between S Ai3 The first end and S Ai4 The second end of the series connection, S Ai3 With S Ai4 A second AC output port is provided between the first AC output port and the second AC output port, and the primary side of the isolation transformer is connected between the first AC output port and the second AC output port, wherein S Ai1 , S Ai2 , S Ai3 , S Ai4 The first end is the emitter and the second end is the collector.

5. The charging module for electric vehicles based on hybrid power processing according to claim 1, characterized in that: The second SiC power processing module includes four third-type power switches T connected in an H-type manner. Ai1 , T Ai2 , T Ai3 , T Ai4 , each third type power switch is connected in parallel with a corresponding capacitor; T Ai1 The second end of the Ai3 The second end of T is connected in series and connected to the third DC input port, and the third DC input port is connected to the first DC output port. Ai2 The first end and T Ai4 The first end of T is connected in series and connected to the fourth DC input port, the fourth DC input port is connected to the first DC output port, Ai1 The first end and T Ai2 The second end of the series connection, T Ai1 With T Ai2 There is a third power AC port between T Ai3 The first end and T Ai4 The second end of the series connection, T Ai3 With T Ai4 A fourth AC output port is provided between the third AC output port and the fourth AC output port, and the primary side of the isolation transformer is connected between the third AC output port and the fourth AC output port, wherein T Ai1 , T Ai2 , T Ai3 , T Ai4 The first end is the source, and the second end is the drain.

6. The charging module for electric vehicles based on hybrid power processing according to claim 2, 4 or 5, characterized in that: The structures adopted by the first Si power processing module, the isolation transformer and the second AC-DC converter include a DAB converter, an LLC resonant converter, a phase-shifted full-bridge converter and a CLLC resonant converter, and the structures adopted by the second SiC power processing module, the isolation transformer and the second AC-DC converter include a DAB converter, an LLC resonant converter, a phase-shifted full-bridge converter and a CLLC resonant converter.

7. The charging module for electric vehicles based on hybrid power processing according to claim 6, characterized in that: When a DAB converter is used, the second AC-DC converter includes four fourth-type power switches connected in an H-type manner, and the fourth-type power switches are IGBTs; an inductor L is connected in series between two AC output ports of the first Si power processing module or the second SiC power processing module. ri The inductor corresponding to the primary side of the isolation transformer.

8. The charging module for electric vehicles based on hybrid power processing according to claim 6, characterized in that: When an LLC resonant converter is used, the second AC-DC converter includes four fourth-type power switches connected in an H-type manner, wherein the fourth-type power switches are IGBTs; a capacitor C is connected in series between two AC output ports of the first Si power processing module or the second SiC power processing module ri 、Inductance L ri The inductor corresponding to the primary side of the isolation transformer.

9. The charging module for electric vehicles based on hybrid power processing according to claim 6, characterized in that: When a phase-shifted full-bridge converter is used, the second AC-DC converter includes four fourth-type power switches connected in H-type, and the fourth-type power switches are diodes; a capacitor C is connected in series between two AC output ports of the first Si power processing module or the second SiC power processing module ri 、Inductance L ri The inductor corresponding to the primary side of the isolation transformer.

10. The charging system for electric vehicles based on hybrid power processing according to claim 1, characterized in that: It comprises a three-phase cascaded multi-port AC-DC converter, a power distribution unit and an electric vehicle charging gun connected in sequence, wherein the three-phase cascaded multi-port AC-DC converter comprises N independent cascaded output ports, and a charging module for an electric vehicle based on hybrid power processing as described in any one of claims 1 to 9, wherein in the charging module, the DC input port of the i-th hybrid power processing unit of phase A / phase B / phase C is connected to the DC output port of the i-th first AC-DC converter of the corresponding phase, and the DC output port of the i-th hybrid power processing unit of phase A is connected to the DC output port of the i-th hybrid power processing unit of phase B and the DC output port of the i-th hybrid power processing unit of phase C, together forming port i, 1≤i≤N; the AC input port of the three-phase cascaded multi-port AC-DC converter is directly connected to the medium-voltage power grid for power distribution.

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