A charging module and system for electric vehicles based on hybrid power processing

Abstract

The application discloses a charging module and system of an electric vehicle 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, comprising 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 at the secondary side of the isolation transformer. 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 ports of the first AC-DC converter and the second AC-DC converter are both connected to a device to be charged. The application solves the problem that the efficiency, cost, power quality and reliability of the charging stack cannot be considered simultaneously.

Description

TECHNICAL FIELD

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

[0002] As an energy supply device, the charging system is a key infrastructure for large-scale promotion and application of new energy vehicles. Electric vehicle charging systems are constantly innovating and come in a variety of types, mainly including AC slow charging and high-power DC fast charging solutions. Current high-power, high-voltage super-charging technology can effectively solve the problem of charging speed. Electric vehicle high-power charging technology architecture can be divided into three categories: fixed power based on traditional power frequency transformers, fixed power based on power electronic transformers, and charging pile based on power sharing. When the output power of the fixed power architecture charger is designed to be very large, it will cause waste of charging capacity and low utilization rate of the charger when charging electric vehicles with small energy storage capacity. If the output power of the charger is designed to be small, although the utilization rate of the charger can be improved, the charging time is prolonged when charging electric vehicles with large energy storage capacity, which is inconvenient for the vehicle owner. With the rapid development of power battery technology, the charging pile based on power sharing has a good development prospect.

[0003] Existing charging piles based on power sharing include full power processing and partial power processing of the charging pile, but the traditional full power processing technology scheme, such as the patent with publication number CN116494790A, has low efficiency and poor power quality, and the full power processing scheme using SiC devices has high cost and low power level. The partial power processing technology scheme also has the problems of poor power quality, low efficiency, complex circuit structure, and poor reliability. In summary, the existing technology schemes cannot achieve the comprehensive optimization of efficiency, cost, power quality, and reliability. SUMMARY

[0004] (I) Technical problems to be solved

[0005] Based on the above problems, the present application provides a charging module and system for electric vehicles based on hybrid power processing, which solves the problem that the efficiency, cost, power quality, and reliability of the charging pile cannot be considered comprehensively.

[0006] (II) Technical solutions

[0007] To address the aforementioned technical problems, this invention provides a charging module for an electric vehicle based on hybrid power processing, comprising 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 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 source. 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.

[0008] Furthermore, the first AC-DC converter adopts an H-bridge converter, including four first-type power switches connected in an H-shape, the first-type power switches being Si-based devices; the first Si power processing module adopts an H-bridge DC-AC converter, including four second-type power switches connected in an H-shape, the second-type power switches being Si-based devices; the second SiC power processing module adopts an H-bridge DC-AC converter, including four third-type power switches connected in an H-shape, the third-type power switches being SiC-based devices; the second AC-DC converter adopts an H-bridge converter, including four fourth-type power switches connected in an H-shape; 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 both the first Si power processing module and the second SiC power processing module are 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; 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 Class I power switches Q connected in an H-type configuration. 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 located between them, Q Ai3 The first end and Q Ai4 The second end is connected in series, Q Ai3 With Q Ai4A second AC input port, Q, is provided on the AC side. Ai1 The second end and Q Ai3 The second end is connected in series and connected to the first DC output port on the DC side, Q Ai2 The first end and Q Ai4 The first terminal 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 terminal of the unit to be charged. 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 terminal 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 an H-shape. Ai1 S Ai2 S Ai3 S Ai4 Each Class II power switch is connected in parallel with a corresponding capacitor; S Ai1 The second end and S Ai3 The second end is connected in series and connected to the first DC input port, and the first DC input port is connected to the first DC output port. Ai2 The first end and S Ai4 The first end is connected in series and then connected to the second DC input port, which is connected to the second DC output port. Ai1 The first end and S Ai2 The second end is connected in series, S Ai1 With S Ai2 A first AC output port is provided between them, S Ai3 The first end and S Ai4 The second end is connected in series, S Ai3 With S Ai4 A second AC output port is provided between the first and second AC output ports, and the primary side of the isolation transformer is connected between the first and second AC output ports. 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 Class III power switches T connected in an H-type configuration. Ai1 T Ai2 T Ai3 TAi4 Each Class III power switch is connected in parallel with a corresponding capacitor; T Ai1 The second end and T Ai3 The second end is connected in series and then connected to the third DC input port, which is connected to the first DC output port. Ai2 The first end and T Ai4 The first end is connected in series and connected to the fourth DC input port, which is then connected to the first DC output port. Ai1 The first end and T Ai2 The second end is connected in series, T Ai1 With T Ai2 A third power AC port is provided between them, T Ai3 The first end and T Ai4 The second end is connected in series, T Ai3 With T Ai4 A fourth AC output port is provided between the third and fourth AC output ports, and the primary side of the isolation transformer is connected between the third and fourth AC output ports. T Ai1 T Ai2 T Ai3 T Ai4 The first end is the source, and the second end is the drain.

[0012] Furthermore, the first Si power processing module, the isolation transformer, and the second AC-DC converter adopt structural forms including DAB converter, LLC resonant converter, phase-shifted full-bridge converter, and CLLC resonant converter, and the second SiC power processing module, the isolation transformer, and the second AC-DC converter adopt structural forms including DAB converter, LLC resonant converter, phase-shifted full-bridge converter, and 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-shape, wherein the fourth-type power switches are IGBTs; 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.

[0014] Furthermore, when an LLC resonant converter is used, the second AC-DC converter includes four fourth-type power switches connected in an H-shape, wherein the fourth-type power switches are IGBTs; 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 Inductor L ri The inductor corresponding to the primary side of the isolation transformer.

[0015] Furthermore, when a phase-shifted full-bridge converter is used, the second AC-DC converter includes four fourth-type power switches connected in an H-shape, wherein the fourth-type power switches are diodes; 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 Inductor L ri The inductor corresponding to the primary side of the isolation transformer.

[0016] This invention also discloses a charging system for electric vehicles 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. The three-phase cascaded multi-port AC-DC converter includes a charging module for electric vehicles based on hybrid power processing as described in any one of claims 1-9, comprising N independent cascaded output ports. 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. The DC output port of the i-th hybrid power processing unit of phase A is connected to the DC output ports of the i-th hybrid power processing unit of phase B and the i-th hybrid power processing unit of phase C, 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-described technical solution of the present invention has the following advantages:

[0019] (1) In this invention, a first Si power processing module and a second SiC power processing module are connected in parallel to the DC output terminal of a first AC-DC converter, and the output terminals of both the first and second AC-DC converters are connected to the device to be charged. This divides the power flow of this invention into three parts: DC power flow, main power flow, and auxiliary power flow. The DC power flow is directly output to the device to be charged, minimizing losses and improving efficiency. The main power flow utilizes a high-power, low-cost Si main power processing unit for low-frequency processing, making the output waveform of the main power flow approximately close to the desired output value, and reducing system switching losses to improve charging efficiency. Energy efficiency; The auxiliary power flow utilizes the high frequency and low loss advantages of the second SiC power processing module to perform high frequency modulation, modulating a smaller power packet to compensate for the high output ripple caused by the low frequency operation of the first Si power processing module. It fully leverages the advantages of the cross-frequency regulation of the hybrid power processing unit combining Si and SiC, suppresses the output current ripple of the charging pile, improves the power quality of electric vehicle charging, helps ensure the long operating life of electric vehicle batteries, and ensures the high power conversion efficiency of the system. Furthermore, the hybrid power processing unit combines the advantages of Si-based devices and SiC-based devices, thereby achieving the comprehensive optimization of charging pile performance and cost.

[0020] (2) The hybrid power processing unit of the present invention is a parallel structure, that is, the DC output terminal 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 terminal of the first AC-DC converter and the output terminal of the second AC-DC converter are both connected to the device to be charged. The three power output methods have good redundancy and fault tolerance capabilities 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, which has a wide range of applicability. Attached Figure Description

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

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

[0024] Figure 2 This is a schematic diagram of the topology of a charging system for an electric vehicle based on hybrid power processing, according to an embodiment of the present invention.

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

[0026] Figure 4 This is a second form of the charging module for an electric vehicle based on hybrid power processing according to an embodiment of the present invention;

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

[0028] Figure 6 This is a schematic diagram comparing the power flow of a charging module for an electric vehicle based on hybrid power processing, according to an embodiment of the present invention.

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

[0030] Figure 8 These are schematic diagrams of four configurations of the hybrid power processing unit according to embodiments of the present invention. Detailed Implementation

[0031] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0032] Embodiment 1 of the present invention is a charging system for electric vehicles based on hybrid power processing, such as... Figures 1-2 As shown, the device 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 N independent cascaded output ports for the charging module. Each 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. Both the first Si power processing module and the second SiC power processing module are 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 source. 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. The first AC-DC converter converts the input AC power into DC power, and can directly output the converted DC power to the device to be charged, i.e., the electric vehicle charging gun, and also outputs it to the first Si power processing module and the second SiC power processing module. The converted DC power is converted into AC power by the power regulation of the first Si power processing module and the second SiC power processing module, and then transformed by the isolation transformer. After the second AC-DC converter converts the transformed AC power into DC power, it is also output to the electric vehicle charging gun after being distributed by the power distribution unit.

[0033] The AC input port of the three-phase cascaded multi-port AC-DC converter is directly connected to the medium-voltage power grid. The three-phase cascaded multi-port AC-DC converter includes N independent cascaded output port charging modules. In each charging module, the DC input port of the i-th hybrid power processing unit in phases A, B, and C is connected to the DC output port of the i-th first AC-DC converter in the corresponding phase. The DC output port of the i-th hybrid power processing unit in phase A is connected to the DC output ports of the i-th hybrid power processing units in phases B and C, forming port i, where 1 ≤ i ≤ N. The power distribution unit includes 2*M*N switching switches. There are M electric vehicle charging guns. The positive terminal of the DC output port of each hybrid power processing unit at 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 terminal of the electric vehicle charging gun. The negative terminal of the DC output port of each hybrid power processing unit at 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 terminal of the electric vehicle charging gun. Among them, 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.

[0034] Embodiment 2 of the present invention is a charging module for an electric vehicle based on hybrid power processing. It is a charging module for any port of any phase in the three-phase cascaded multi-port AC-DC converter of Embodiment 1, such as... Figure 3 As shown, the device 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. Both the first Si power processing module and the second SiC power processing module are 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 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. The first AC-DC converter converts the input AC power into DC power, and can directly output the converted DC power to the device to be charged, as well as to the first Si power processing module and the second SiC power processing module. The converted DC power is converted into AC power by the 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 then converted into DC power by the second AC-DC converter, and after being distributed by the power distribution unit, it is also output to the device to be charged.

[0035] To address the challenge of balancing cost and performance improvement in current AC-DC converters based on single Si or WBG devices, this embodiment proposes a hybrid power processing method combining Si and SiC. The method fully leverages the advantages of low cost and high capacity of Si-based devices and the advantages of high frequency and low loss of WBG devices. The first AC-DC converter and the first Si power processing unit are composed of Si-based devices, while the second SiC power processing unit is composed of third-generation semiconductor SiC-based devices.

[0036] Furthermore, the first AC-DC converter adopts an H-bridge converter, including four first-type power switches connected in an H-shape, the first-type power switches being Si-based devices; the first Si power processing module adopts an H-bridge DC-AC converter, including four second-type power switches connected in an H-shape, the second-type power switches being Si-based devices; the second SiC power processing module adopts an H-bridge DC-AC converter, including four third-type power switches connected in an H-shape, the third-type power switches being SiC-based devices; the second AC-DC converter adopts an H-bridge converter, including four fourth-type power switches connected in an H-shape; 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 both the first Si power processing module and the second SiC power processing module are 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; 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 is an H-bridge converter. This embodiment is described using the charging module at the i-th port of phase A, which includes four first-type power switches Q connected in an H-shape. 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 located between them, Q Ai3 The first end and Q Ai4 The second end is connected in series, Q Ai3 With Q Ai4 A second AC input port, Q, is provided on the AC side. Ai1 The second end and Q Ai3 The second end is connected in series and connected to the first DC output port on the DC side, Q Ai2The first end and Q Ai4 The first terminal 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 terminal of the unit to be charged. 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 terminal of the unit to be charged. The first type of power switch Q... Ai1 Q Ai2 Q Ai3 Q Ai4 For IGBTs, 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. It has relatively large conduction and switching losses and low switching speed, and is generally suitable for low- and medium-frequency applications. The first AC-DC converter utilizes high-power, low-cost IGBTs to convert AC to DC and simultaneously perform low-frequency processing.

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

[0040] In this embodiment, the first Si power processing module employs an H-bridge DC-AC converter, comprising four H-connected second-type power switches, which 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 an isolation transformer. Specifically, the first Si power processing module comprises four H-connected second-type power switches. Ai1 S Ai2 S Ai3 S Ai4 Each Class II power switch is connected in parallel with a corresponding capacitor; S Ai1 The second end and S Ai3 The second end is connected in series and connected to the first DC input port, and the first DC input port is connected to the first DC output port. Ai2 The first end and S Ai4 The first end is connected in series and then connected to the second DC input port, which is connected to the second DC output port. Ai1 The first end and S Ai2 The second end is connected in series, SAi1 With S Ai2 A first AC output port is provided between them, S Ai3 The first end and S Ai4 The second end is connected in series, S Ai3 With S Ai4 A second AC output port is provided between the first and second AC output ports. A first inductor on the primary side of the isolation transformer is connected between the first and second AC output ports. The second type of power switch S... Ai1 S Ai2 S Ai3 S Ai4 For IGBTs, Class II power switches 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 a 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. It has large conduction and switching losses and low switching speed, and is generally suitable for low- and medium-frequency applications.

[0042] In this embodiment, the second SiC power processing module employs an H-bridge DC-AC converter, comprising four H-connected third-type power switches, which 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 an isolation transformer. Specifically, the second SiC power processing module includes four H-connected third-type power switches T Ai1 T Ai2 T Ai3 T Ai4 Each Class III power switch is connected in parallel with a corresponding capacitor; T Ai1 The second end and T Ai3 The second end is connected in series and then connected to the third DC input port, which is connected to the first DC output port. Ai2 The first end and T Ai4 The first end is connected in series and connected to the fourth DC input port, which is then connected to the first DC output port. Ai1 The first end and T Ai2 The second end is connected in series, T Ai1 With T Ai2 A third power AC port is provided between them, T Ai3 The first end and T Ai4 The second end is connected in series, TAi3 With T Ai4 A fourth AC output port is provided between the third and fourth AC output ports. A second inductor on the primary side of the isolation transformer is connected between the third and fourth AC output ports. A third type of 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 a third type of 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). WBGs are semiconductor devices made from materials with a large bandgap, typically gallium nitride (GaN) or silicon carbide (SiC). This wide-bandgap semiconductor device is used for high-frequency modulation compensation. Here, the third type of power switch uses a SiC MOSFET, which is a metal-oxide-semiconductor field-effect transistor based on silicon carbide (SiC) material. It features lower conduction and switching losses, faster switching speeds, and is suitable for high-frequency applications.

[0044] The second AC-DC converter uses an H-bridge converter, including four Class IV power switches M connected in an H-type configuration. Ai1 M Ai2 M Ai3 M Ai4 M Ai1 The first end and M Ai2 The second end is connected in series, M Ai1 With M Ai2 A third AC input port is provided between them, M Ai3 The first end and M Ai4 The second end is connected in series, M Ai3 With M Ai4 A fourth AC input port is provided between them, M Ai1 The second end and M Ai3 The second terminal is connected in series and then connected to the third DC output port, M Ai2 The first end and M Ai4 The first end is 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. The unit to be charged is connected between the third DC output port and the fourth DC output port.

[0045] In this embodiment, the first Si power processing module, the isolation transformer, and the second AC-DC converter can adopt any DC-DC converter form, including DAB converter, LLC resonant converter, phase-shifted full-bridge converter, and CLLC resonant converter, etc. Similarly, the second SiC power processing module, the isolation transformer, and the second AC-DC converter can adopt any DC-DC converter form, including DAB converter, LLC resonant converter, phase-shifted full-bridge converter, and CLLC resonant converter, etc. Furthermore, the DC-DC converter structure adopted by the first Si power processing module, the isolation transformer, and the second AC-DC converter can be the same as or different from the DC-DC converter structure adopted by the second SiC power processing module, the isolation transformer, and the second AC-DC converter, without affecting the choice of form.

[0046] When using a DAB converter, such as Figure 3 As shown, the second AC-DC converter includes four Class IV power switches connected in an H-type configuration, with Class IV power switches M... Ai1 M Ai2 M Ai3 M Ai4 For an IGBT, the first terminal is the emitter, and the second terminal is the 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, namely: the series inductor L between the first AC output port and the second AC output port of the first Si power processing module. ri The first inductor on the primary side of the isolation transformer, or the series inductor L between the third and fourth AC output ports of the second SiC power processing module. ri And the second inductor on the primary side of the isolation transformer;

[0047] When using an LLC resonant converter, such as Figure 4 As shown, the second AC-DC converter includes four Class IV power switches connected in an H-type configuration, with Class IV power switches M... Ai1 M Ai2 M Ai3 M Ai4 It is an IGBT, with the first terminal being the emitter and the second terminal being the 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 Inductor L ri The inductor corresponding to the primary side of the isolation transformer, i.e., 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 Inductor Lri The capacitor C is connected in series between the first inductor on the primary side of the isolation transformer, or between the third and fourth AC output ports of the second SiC power processing module. ri Inductor L ri And the second inductor on the primary side of the isolation transformer;

[0048] When using a phase-shifted full-bridge converter, such as Figure 5 As shown, the second AC-DC converter includes four Class IV power switches connected in an H-type configuration, with Class IV power switches M... Ai1 M Ai2 M Ai3 M Ai4 It is a diode, with the first terminal being the positive terminal and the second terminal being the negative terminal; 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 Inductor L ri The inductor corresponding to the primary side of the isolation transformer, i.e., 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 Inductor L ri The first inductor on the primary side of the isolation transformer; the capacitor C connected in series between the third and fourth AC output ports of the second SiC power processing module. ri Inductor L ri And the 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 inductor L. fi One end, inductor L fi A capacitor C is connected between the other end and the fourth DC output port. fi .

[0050] The power flow of the charging module during normal operation is as follows: Figure 6 As shown in Figure (a), firstly, the power P input to the charging grid... 总 Divided into two power flows P 12 And P3, where the direct power current P3 is directly output through the charging gun, has the least loss and the highest efficiency, while the mixed power current P 12Input hybrid power processing unit. The main power flow P1 of the first AC-DC converter and the first Si power processing module utilizes high-power, low-cost Si-based devices for low-frequency processing, making the output waveform of the first Si power processing unit approximately close to the desired value. The auxiliary power flow P2 of the second SiC power processing module utilizes the high-frequency and low-loss advantages of SiC devices to perform high-frequency modulation on a portion of the energy flow, modulating a smaller energy packet to compensate for the ripple caused by the low-frequency operation of the Si-based devices, thus achieving the function of active hardware filtering. The principle is as follows: Figure 7 As shown. Compared to Figure 6 Figure (b) shows that the traditional method of directly processing the full power flow by a DC-DC module has higher efficiency.

[0051] Furthermore, the hybrid power processing unit comprises 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. Among them. Figure 8 Figure (a) shows a 1:1 configuration combining a first Si power processing module and a second SiC power processing module, which focuses on low-cost, low-power applications. Figure 8 Figure (b) shows an X:1 configuration consisting of X first Si power processing modules and one second SiC power processing module, which is geared towards low-cost, high-power applications. Figure 8 Figure (c) shows a 1:Y configuration combining one first Si power processing module and Y second SiC power processing modules, focusing on high-efficiency applications with low ripple (high power quality). Figure 8 Figure (d) shows an X:Y configuration combining X first Si power processing modules and Y second SiC power processing modules, emphasizing high-power applications with low ripple (high power quality), where X>1 and Y>1. Therefore, the most suitable hybrid power processing unit configuration can be selected based on different requirements and configuration characteristics.

[0052] In summary, the above-described electric vehicle charging module and system based on hybrid power processing has the following beneficial effects:

[0053] (1) In this invention, a first Si power processing module and a second SiC power processing module are connected in parallel to the DC output terminal of a first AC-DC converter, and the output terminals of both the first and second AC-DC converters are connected to the device to be charged. This divides the power flow of this invention into three parts: DC power flow, main power flow, and auxiliary power flow. The DC power flow is directly output to the device to be charged, minimizing losses and improving efficiency. The main power flow utilizes a high-power, low-cost Si main power processing unit for low-frequency processing, making the output waveform of the main power flow approximately close to the desired output value, and reducing system switching losses to improve charging efficiency. Energy efficiency; The auxiliary power flow utilizes the high frequency and low loss advantages of the second SiC power processing module to perform high frequency modulation, modulating a smaller power packet to compensate for the high output ripple caused by the low frequency operation of the first Si power processing module. It fully leverages the advantages of the cross-frequency regulation of the hybrid power processing unit combining Si and SiC, suppresses the output current ripple of the charging pile, improves the power quality of electric vehicle charging, helps ensure the long operating life of electric vehicle batteries, and ensures the high power conversion efficiency of the system. Furthermore, the hybrid power processing unit combines the advantages of Si-based devices and SiC-based devices, thereby achieving the comprehensive optimization of charging pile performance and cost.

[0054] (2) The hybrid power processing unit of the present invention is a parallel structure, that is, the DC output terminal 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 terminal of the first AC-DC converter and the output terminal of the second AC-DC converter are both connected to the device to be charged. The three power output methods have good redundancy and fault tolerance capabilities 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, which has a wide range of applicability.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit it; although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all 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, The system includes a first AC-DC converter and a hybrid power processing unit. The hybrid power processing unit is an isolated DC-DC converter structure, comprising 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. Both the first Si power processing module and the second SiC power processing module are 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 ports of the 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. The first AC-DC converter is used to convert the input AC power into DC power. It can directly output the converted DC power to the device to be charged, or it can 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 by the power regulation of the first Si power processing module and the second SiC power processing module. After being transformed by the isolation transformer, the second AC-DC converter converts the transformed AC power into DC power. After being distributed by the power distribution unit, it is output to the device to be charged. The hybrid power processing unit includes four configurations: (1) a 1:1 configuration combining one first Si power processing module and one second SiC power processing module, which focuses on low-cost small and medium power applications; (2) an X:1 configuration combining X first Si power processing modules and one second SiC power processing module, which focuses on low-cost high-power applications; (3) a 1:Y configuration combining one first Si power processing module and Y second SiC power processing modules, which focuses on low-ripple high-efficiency applications; and (4) an X:Y configuration combining X first Si power processing modules and Y second SiC power processing modules, which focuses on low-ripple high-power applications, where X>1 and Y>1.

2. The charging module for an electric vehicle based on hybrid power processing according to claim 1, characterized in that, The first AC-DC converter uses an H-bridge converter, including four first-type power switches connected in an H-shape, the first-type power switches being Si-based devices; the first Si power processing module uses an H-bridge DC-AC converter, including four second-type power switches connected in an H-shape, the second-type power switches being Si-based devices; the second SiC power processing module uses an H-bridge DC-AC converter, including four third-type power switches connected in an H-shape, the third-type power switches being SiC-based devices; the second AC-DC converter uses an H-bridge converter, including four fourth-type power switches connected in an H-shape; 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 both the first Si power processing module and the second SiC power processing module are 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; 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 an electric vehicle based on hybrid power processing according to claim 1, characterized in that, The first AC-DC converter includes four Class I power switches Q connected in an H-type configuration. 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 located between them, Q Ai3 The first end and Q Ai4 The second end is connected in series, Q Ai3 With Q Ai4 A second AC input port, Q, is provided on the AC side. Ai1 The second end and Q Ai3 The second end is connected in series and connected to the first DC output port on the DC side, Q Ai2 The first end and Q Ai4 The first terminal 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 terminal of the unit to be charged. 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 terminal 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 an electric vehicle based on hybrid power processing according to claim 3, characterized in that, The first Si power processing module includes four Type II power switches S connected in an H-type configuration. Ai1 S Ai2 S Ai3 S Ai4 Each Class II power switch is connected in parallel with a corresponding capacitor; S Ai1 The second end and S Ai3 The second end is connected in series and connected to the first DC input port, and the first DC input port is connected to the first DC output port. Ai2 The first end and S Ai4 The first end is connected in series and then connected to the second DC input port, which is connected to the second DC output port. Ai1 The first end and S Ai2 The second end is connected in series, S Ai1 With S Ai2 A first AC output port is provided between them, S Ai3 The first end and S Ai4 The second end is connected in series, S Ai3 With S Ai4 A second AC output port is provided between the first and second AC output ports, and the primary side of the isolation transformer is connected between the first and second AC output ports. 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 an electric vehicle based on hybrid power processing according to claim 3, characterized in that, The second SiC power processing module includes four Class III power switches T connected in an H-type configuration. Ai1 T Ai2 T Ai3 T Ai4 Each Class III power switch is connected in parallel with a corresponding capacitor; T Ai1 The second end and T Ai3 The second end is connected in series and then connected to the third DC input port. The third DC input port is connected to the first DC output port. Ai2 The first end and T Ai4 The first end is connected in series and connected to the fourth DC input port, which is then connected to the first DC output port. Ai1 The first end and T Ai2 The second end is connected in series, T Ai1 With T Ai2 A third power AC port is provided between them, T Ai3 The first end and T Ai4 The second end is connected in series, T Ai3 With T Ai4 A fourth AC output port is provided between the third and fourth AC output ports, and the primary side of the isolation transformer is connected between the third and fourth AC output ports. 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 an electric vehicle based on hybrid power processing according to claim 2, 4, or 5, characterized in that, The first Si power processing module, the isolation transformer, and the second AC-DC converter adopt the following structural forms: DAB converter, LLC resonant converter, phase-shifted full-bridge converter, and CLLC resonant converter. The second SiC power processing module, the isolation transformer, and the second AC-DC converter adopt the following structural forms: DAB converter, LLC resonant converter, phase-shifted full-bridge converter, and CLLC resonant converter.

7. The charging module for an electric vehicle 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 Type IV power switches connected in an H-type configuration, wherein the Type IV power switches are IGBTs; 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.

8. The charging module for an electric vehicle 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 Type IV power switches connected in an H-type configuration, wherein the Type IV power switches are IGBTs; 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 Inductor L ri The inductor corresponding to the primary side of the isolation transformer.

9. The charging module for an electric vehicle 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 an H-shape, wherein the fourth-type power switches are diodes; 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 Inductor L ri The inductor corresponding to the primary side of the isolation transformer.

10. A charging system for an electric vehicle based on hybrid power processing, characterized in that, The device 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 for electric vehicles based on hybrid power processing as described in any one of claims 1-9, comprising N independent cascaded output ports. 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. The DC output port of the i-th hybrid power processing unit of phase A is connected to the DC output ports of the i-th hybrid power processing unit of phase B and the i-th hybrid power processing unit of phase C, forming port i, where 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.

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