Power conversion system and vehicle

Abstract

To provide a power conversion system and a vehicle related to filtering.SOLUTION: A power conversion system includes: a DC power supply for supplying first DC voltage; an inverter module for converting the first DC voltage into first AC voltage; a power conversion module for converting the first DC voltage into second AC voltage or converting external third AC voltage of the power conversion system into second DC voltage; a first stage filter circuit connected between first pair of terminals of the DC power supply and second pair of terminals of the inverter module, and used for removing noise signals within a first frequency interval and a second frequency interval; and a second stage filter circuit connected between third pair of terminals of the first stage filter circuit and fourth pair of terminals of the power conversion module, and used for removing a noise signal within the second frequency interval. The second frequency interval is different from the first frequency interval.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] This application relates to power conversion systems and vehicles related to filtering. [Background technology]

[0002] The power conversion system in a vehicle is an important part for realizing the operation of the vehicle. The power conversion system includes an inverter module and a power conversion module. The operation process of the inverter module includes converting DC power (e.g., DC power from an on-board energy storage device) into AC power to rotate and drive a rotary motor, thereby operating the vehicle. Meanwhile, a power conversion module such as an on-board charging circuit (OBC) can obtain AC voltage from the outside (e.g., the voltage of the power grid may be connected to the on-board charger via a grounded AC charging pile or via an AC charging port) and convert the AC voltage into a DC voltage (e.g., a higher voltage such as 350 V) to charge an energy storage device (e.g., a battery) in the vehicle, or the DC voltage can be further converted into a voltage (e.g., a lower DC voltage such as 12 V) to supply power to other components in the vehicle. Alternatively, the DC voltage of the energy storage device in the vehicle may also be converted into AC voltage through the power conversion module, thereby supplying power to external components requiring AC voltage. That is, the power conversion module can be bidirectional.

[0003] FIG. 1 illustrates an exemplary structure of a power conversion system in a vehicle. As illustrated in FIG. 1, the power conversion system 100 may include a DC power source 10, an inverter module 20, and a power conversion module 30. The DC power source may provide a DC voltage to the inverter module, which then converts the DC voltage to generate an AC voltage for rotating a rotary motor. On the other hand, the power conversion module may convert another AC voltage (e.g., AC voltage from a power grid) input to its input terminal into a DC voltage to charge a DC power source (including an energy storage device), or the DC voltage may be further converted using a DC voltage conversion module included in the power conversion system to provide a voltage (e.g., 12 V) for powering other components in the vehicle. Alternatively, the DC voltage of the DC power source 10 may also be converted to an AC voltage via the power conversion module 30.

[0004] Additionally, both the inverter module and the power conversion module have associated switching devices that are switched at high frequencies. For example, the switching devices included in the inverter bridge arms of the inverter and the switching devices included in the rectifier circuit and / or the DC voltage conversion module associated with the power conversion module may operate in pulse-width modulation (PWM) mode and may be switched between on and off states, causing noise signals to be generated by the switching on the vehicle DC link. Therefore, it is often necessary to set up additional filter circuits on the vehicle DC link for EMC processing. Typically, as shown by the dotted lines in FIG. 1, a filter structure is provided on each of the DC links corresponding to the inverter module and the power conversion module, so that noise signals of different frequency intervals corresponding to the two circuits are individually filtered.

[0005] However, the following problem exists when both filter structures are arranged independently. Although there is no large-capacitance X capacitor in the filter structure for the DC link corresponding to the power conversion module (which may also include a DC voltage conversion module) (e.g., usually due to considerations of noise frequency distribution range, volume, and cost), huge low-frequency noise is always generated because the switching frequency associated with the power conversion module can still be around 100 kHz. Therefore, it is usually difficult to eliminate the low-frequency noise to meet customer requirements. In addition, there is always a resonance effect between the two filter structures on the two DC links, which results in poor filtering performance at high frequencies. Therefore, both of these situations are disadvantageous in terms of the electromagnetic compatibility (EMC) performance of the product.

[0006] Therefore, there is a need for an improved filter structure that can reject noise signals at different frequency intervals on the DC link in order to ensure EMC performance while minimizing cost and volume. Summary of the Invention

[0007] According to one aspect of the present application, there is provided a power conversion system including: a DC power source for providing a first DC voltage; an inverter module for converting the first DC voltage to a first AC voltage; a power conversion module for converting the first DC voltage to a second AC voltage or for converting a third AC voltage from outside the power conversion system to the second DC voltage; a first stage filter circuit connected between a first pair of terminals of the DC power source and a second pair of terminals of the inverter module, the first stage filter circuit being used to reject noise signals having frequencies within a first frequency interval and a second frequency interval; and a second stage filter circuit connected between a third pair of terminals of the first stage filter circuit and a fourth pair of terminals of the power conversion module, the second stage filter circuit being used to reject noise signals having frequencies within the second frequency interval, wherein the second frequency interval is different from the first frequency interval.

[0008] According to one embodiment of the present application, switching of switching devices in the inverter module causes noise signals having frequencies within a first frequency interval and within a second frequency interval, and switching of switching devices associated with the power conversion module causes noise signals having frequencies within the first frequency interval and within the second frequency interval.

[0009] According to an embodiment of the present application, the maximum value of the first frequency interval is less than or equal to the minimum value of the second frequency interval.

[0010] According to one embodiment of the present application, the first frequency interval is equal to or greater than 100 kHz and equal to or less than 30 MHz, and the second frequency interval is equal to or greater than 30 MHz.

[0011] According to one embodiment of the present application, the first-stage filter circuit and the second-stage filter circuit are electromagnetic interference prevention filter circuits, each including at least one X capacitor, at least one Y capacitor, and at least one inductor.

[0012] According to one embodiment of the present application, the number of at least one of the X capacitors, the Y capacitors, or the inductors in the second-stage filter circuit is made smaller than the number of the corresponding at least one of the X capacitors, the Y capacitors, or the inductors in the first-stage filter circuit, or the parameter value of at least one of the X capacitors, the Y capacitors, or the inductors in the second-stage filter circuit is made smaller than the parameter value of the corresponding at least one of the X capacitors, the Y capacitors, or the inductors in the first-stage filter circuit.

[0013] According to an embodiment of the present application, the first stage filter circuit includes two common mode inductors, and the second stage filter circuit includes one common mode inductor.

[0014] According to one embodiment of the present application, the first stage filter circuit includes a first common mode inductor, a second common mode inductor, a first X capacitor, and a second X capacitor, two pins of the first common mode inductor are connected to a first pair of terminals of a DC power supply, other two pins of the first common mode inductor are connected to both ends of the first X capacitor, two pins of the second common mode inductor are connected to both ends of the first X capacitor, and other two pins of the second common mode inductor are connected to both ends of the second X capacitor. the second-stage filter circuit includes a third common mode inductor, a third X capacitor, and a fourth X capacitor, two pins of the third common mode inductor are connected to both ends of the second X capacitor and the other two pins of the third common mode inductor are connected to both ends of the third X capacitor, the third X capacitor is connected in parallel to the fourth X capacitor, and both ends of the fourth X capacitor are connected to a fourth pair of terminals of the power conversion module.

[0015] According to one embodiment of the present application, the power conversion system further includes a DC voltage conversion module, which is used to convert the second DC voltage into a third DC voltage suitable for powering the components to be powered.

[0016] According to one embodiment of the present application, the DC voltage conversion module is integrated with the power conversion module.

[0017] According to an embodiment of the present application, the second DC voltage is further used to charge a DC power source.

[0018] According to another aspect of the present disclosure, a vehicle is provided, the vehicle including a power conversion system as described above.

[0019] In the power conversion system and vehicle provided in the embodiments of the present application, two filter structures are arranged. One of the two filter structures functions as a common filter structure that removes noise signals in a first frequency interval and a second frequency interval, and the other filter structure is connected to a pair of terminals of the common filter structure, thereby further removing noise signals in the second frequency interval at a position closer to the power conversion module. Therefore, the filtering requirements for noise signals generated by the inverter module and the power conversion module can be met. This configuration also reduces the number or parameter values ​​of filter devices in the filter structure, thereby reducing costs, volume, etc.

[0020] The drawings illustrate various embodiments of various aspects of the present application and, together with the specification, serve to explain the principles of the present application. Those skilled in the art will understand that the specific embodiments illustrated in the drawings are for illustrative purposes only and are not intended to limit the scope of the present application. In the drawings: [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 shows an exemplary structure of a power conversion system. [Figure 2] FIG. 2 shows an exemplary configuration of a power conversion system with a shared filter circuit. [Figure 3] FIG. 3 illustrates an exemplary structure of a power conversion system with filtering function according to an embodiment of the present application. [Figure 4] FIG. 4 shows an exemplary structure of the first and second stage filter circuits. [Figure 5] FIG. 5 is a schematic diagram of a vehicle according to an embodiment of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0022] Although the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application, it should be understood that the described embodiments are only some, not all, of the embodiments of the present application. Based on the embodiments described herein, any embodiment that a person skilled in the art can obtain without inventive efforts falls within the protection scope of the present application.

[0023] As described above, the independently arranged filter structure in Fig. 1 usually has problems in that it is difficult to remove low frequency noise and the filtering performance at high frequencies is degraded due to the resonance effect. Therefore, in order to ensure EMC performance while minimizing cost and volume, there is a demand for an improved filter structure that can remove noise signals at different frequency intervals on the DC link.

[0024] In the context of this application, an in-vehicle application scenario is used as an example for explanation. However, it will be understood that the solution of this application is not limited to the in-vehicle application scenario and can be applied to other scenarios. For example, a power conversion module (e.g., an on-board charger (OBC) circuit) in the in-vehicle application scenario may be a power conversion module with bidirectional power conversion function in other application scenarios.

[0025] In one embodiment, considering that the inverter module and the power conversion module are usually highly integrated, and considering that the frequency interval of the noise signals caused by the switching of the inverter module's switching devices is substantially the same as that of the noise signals caused by the switching of the switching devices associated with the power conversion module (contained in the power conversion module itself or in an associated (integrated) DC voltage conversion module), for example, in the range of 100 kHz to 245 MHz, it is possible to consider using only the filter structure for the inverter module, as shown in Figure 2, which can reduce cost and volume to a certain extent. However, due to the different placement positions of the inverter module and the power conversion module, tests have shown that this filter structure cannot effectively remove high-frequency (e.g., above 30 MHz) noise signals caused by the power conversion module, which may affect EMC performance.

[0026] Therefore, embodiments of the present application provide another improved power conversion system for eliminating both noise signals caused by the inverter module and the power conversion module.

[0027] FIG. 3 illustrates an exemplary structure of a power conversion system with filtering function according to an embodiment of the present application.

[0028] As shown in FIG. 3, the power conversion system 300 includes a DC power supply 310, an inverter module 320, a power conversion module 330, a first stage filter circuit 340, and a second stage filter circuit 350.

[0029] The DC power source 310 may be used to provide the first DC voltage. For example, the DC power source 310 may be various energy storage devices, such as a supercapacitor and a battery. The DC power source 310 may be connected to an on-board DC link via a connector. Optionally, in addition to the energy storage device, the DC power source may include or be associated with other auxiliary circuits, such as a protection circuit or a charge / discharge management circuit, which is not limited in this application.

[0030] The inverter module 320 may be used to convert a first DC voltage from a DC power source into a first AC voltage. For example, the input terminal (T2) of the inverter module may receive a DC voltage (which may be obtained by filtering the DC voltage output by the DC power source through a first-stage filter circuit, which will be described later), and an inversion process is realized by high-frequency switching of its internal switching devices, thereby outputting an AC voltage at the output terminal. The AC voltage is used as a drive signal to rotate a rotary motor. For example, the inverter module may include a single-phase or three-phase inverter bridge circuit.

[0031] The power conversion module 330 (e.g., an on-board charger) may be used to convert a first DC voltage from the DC power source 310 to a second AC voltage, or to convert a third AC voltage from outside the power conversion system to a second DC voltage (e.g., a higher DC voltage that can charge the DC power source). The amplitude of the second AC voltage may be the same as or different from the amplitude of the third AC voltage. Optionally, as an example, the third AC voltage may be an AC voltage from a power grid and used as an input to the power conversion system, whereby the power conversion module's voltage conversion (e.g., including AC-to-DC conversion and optional DC-to-AC conversion) may convert it to an appropriate level of voltage (e.g., a higher level voltage) that can be used to charge an energy storage device in the DC power source. Optionally, the power conversion module may include a full-bridge topology circuit, whereby AC-to-DC conversion or DC-to-AC conversion is performed depending on the direction of the input power.

[0032] Optionally, the power conversion system 300 may further include a DC voltage conversion module, such as a DC-DC conversion module. The DC voltage conversion module is used to further convert the second DC voltage (obtained by converting the third AC voltage input to the power conversion module 330) into a third DC voltage (e.g., 12 V) suitable for powering the components to be powered, and the DC voltage output by the DC voltage conversion module may be filtered by a second-stage filter circuit, described below, before being supplied to the components to be powered. Optionally, the DC voltage conversion module may be integrated with the power conversion module 330. Optionally, the DC voltage conversion module may include a step-down circuit, such as a buck circuit, a fly-back circuit, or other DC-DC circuit.

[0033] The first-stage filter circuit 340 may be connected between a first pair of terminals (T1) of the DC power supply 310 and a second pair of terminals (T2) of the inverter module 320, and is used to reject noise signals having frequencies within a first frequency interval and a second frequency interval. The second-stage filter circuit 350 may be connected between a third pair of terminals (T3) of the first-stage filter circuit 340 and a fourth pair of terminals (T4) of the power conversion module, and is used to reject noise signals having frequencies within a second frequency interval different from the first frequency interval.

[0034] For example, switching of switching devices in the inverter module and switching devices associated with the power conversion module (e.g., switching devices in the power conversion module and / or switching devices in an associated DC voltage conversion module) cause noise signals having frequencies within a first frequency interval and within a second frequency interval (e.g., determined by measurement to be between 100 kHz and 245 MHz). For example, the maximum value of the first frequency interval may be less than or equal to the minimum value of the second frequency interval. Optionally, according to the frequency measurements of the noise signals caused by the switching devices of the inverter module and the switching devices associated with the power conversion module, the first frequency interval may be greater than or equal to 100 kHz and less than or equal to 30 MHz, and the second frequency interval may be greater than or equal to 30 MHz.

[0035] That is, the first-stage filter circuit is used as a common filter structure that is used to remove noise signals caused by the switching devices of the inverter module and the switching devices associated with the power conversion module in the same frequency intervals (e.g., the frequency intervals of 100 kHz or more and 30 MHz or less, and the frequency intervals of 30 MHz or more (optionally, 245 MHz or less)), and the second-stage filter circuit can be considered as a dedicated filter structure associated with the power conversion module that can remove noise signals having high frequencies (e.g., 30 MHz or more) that may still be present near the fourth pair of terminals of the power conversion module after being removed by the first-stage filter circuit. In this way, the two filter circuits work together. When the first-stage filter circuit is used only for the filtering process of the inverter module, it may maintain its structure, and the second-stage filter circuit may be better specialized for removing frequency intervals having relatively high frequencies (above 30 MHz) related to the power conversion module, so that the number of filter devices or the parameter values ​​of some filter devices in the second-stage filter circuit can be correspondingly reduced. In addition, since the frequency intervals targeted by the two filter circuits are not exactly the same, the resonance effect between the two filter structures can be correspondingly alleviated, thereby correspondingly improving the EMC performance.

[0036] Therefore, optionally, the first-stage filter circuit 340 and the second-stage filter circuit 350 are electromagnetic interference prevention filter circuits, each including at least one X capacitor, at least one Y capacitor, and at least one inductor. The X capacitor is a capacitor connected across two wires of the DC link, and generally, a metal film capacitor may be selected and used. The Y capacitor is a capacitor connected across two wires of the DC link and the ground, and generally configured as a pair. When common-mode interference occurs, the magnetic flux directions of the two coils of the common-mode inductor (e.g., a common-mode choke) become the same, and after being combined, the total inductance increases rapidly. Therefore, a large inductive reactance is presented to the common-mode signal, making it difficult for the common-mode signal to pass, thereby reducing the common-mode interference.

[0037] In some embodiments of the present disclosure, the number of at least one of the X capacitors, Y capacitors, or inductors in the second-stage filter circuit 350 is smaller than the number of the corresponding at least one of the X capacitors, Y capacitors, or inductors in the first-stage filter circuit 340, or the parameter value of the at least one of the X capacitors, Y capacitors, or inductors in the second-stage filter circuit 350 is smaller than the parameter value of the corresponding at least one of the X capacitors, Y capacitors, or inductors in the first-stage filter circuit 340. For example, the first-stage filter circuit 340 may include two common-mode inductors, and the second-stage filter circuit 350 may include one common-mode inductor.

[0038] FIG. 4 shows an exemplary structure of the first and second stage filter circuits.

[0039] 4 , the first-stage filter circuit 340 may include a first common-mode inductor Lc1, a second common-mode inductor Lc2, a first X capacitor Cx1, and a second X capacitor Cx2. Two pins of the first common-mode inductor Lc1 are connected to a first pair of terminals (T1) of the DC power supply, two other pins of the first common-mode inductor Lc1 are connected to both ends of the first X capacitor Cx1, two pins of the second common-mode inductor Lc2 are connected to both ends of the first X capacitor Cx1, and two other pins of the second common-mode inductor Lc2 are connected to both ends of the second X capacitor Cx2, both ends of the second X capacitor Cx2 are connected to a second pair of terminals (T2) of the inverter module 320.

[0040] The second-stage filter circuit includes a third common mode inductor Lc3, a third X capacitor Cx3, and a fourth X capacitor Cx4, two pins of the third common mode inductor are connected to both ends of the second X capacitor Cx2 (i.e., the second pair of terminals (T2) of the first-stage filter circuit), and the other two pins of the third common mode inductor are connected to both ends of the third X capacitor Cx3, which is connected in parallel to the fourth X capacitor Cx4, and both ends of the fourth X capacitor Cx4 are connected to the fourth pair of terminals (T4) of the power conversion module.

[0041] Additionally, there are multiple pairs of Y capacitors (Cy1, Cy2, ..., Cy8) in the first stage filter circuit and in the second stage filter circuit, which further improves the EMC performance of the circuit.

[0042] Optionally, the first stage filter circuit may be disposed on the main circuit board of the inverter module, and / or the second stage filter circuit may be disposed on the main circuit board of the power conversion module.

[0043] Therefore, the structures of the first-stage filter circuit and the second-stage filter circuit shown in Figure 4 ensure the structure of the first-stage filter circuit, while the second-stage filter structure can correspondingly reduce the number of filter devices (or parameter values ​​(not shown)) compared with the independently arranged filter circuits as shown in Figure 1, thereby reducing cost and volume. In addition, compared with the filter structure shown in Figure 2, it can better remove high-frequency noise signals in the power conversion module branch.

[0044] Based on the above description with reference to Figures 3 and 4, experimental tests were conducted. During the experiments, based on the fact that the first-stage filter circuit can completely eliminate noise caused by switching of the inverter module, the power conversion module (and the associated DC voltage conversion module) was operated at rated power to test the circuit performance. The experimental results showed that, compared to the structures shown in Figures 1 and 2, these noises can be better eliminated under low-frequency conditions (e.g., for noise signals below 2 MHz) and high-frequency conditions (e.g., for noise signals below 30 MHz to 108 Hz), and as mentioned above, the cost and volume requirements can be reduced.

[0045] According to another aspect of the present application, the present application further provides a vehicle. The vehicle may be an electrified vehicle, such as a battery electric vehicle (BEV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), an extended range EV, or a fuel cell electric vehicle (FCEV). The vehicle may also be a hydrogen-powered vehicle.

[0046] FIG. 5 shows a schematic diagram of a vehicle according to an embodiment of the present application.

[0047] As shown in Fig. 5, a vehicle 500 according to the present application includes the above-described power conversion system 300 according to the present application. For a detailed description of the vehicle 500 according to the present application, reference may be made to the descriptions regarding Figs. 3 and 4 of the present application, which will not be repeated here for the sake of brevity.

[0048] Although the subject matter of the present application has been described in detail with reference to various specific exemplary embodiments, each example is provided to illustrate the disclosure, not to limit it. Those skilled in the art will be able to readily make modifications, variations, and equivalents to such embodiments after understanding the foregoing. Accordingly, the present invention is not intended to exclude such modifications, variations, and / or additions to the subject matter of the present application that would be obvious to those skilled in the art. For example, some features illustrated or described as working with one embodiment can be used with another embodiment to form a further embodiment. Accordingly, it is intended that the present disclosure cover such modifications, variations, and equivalents.

[0049] In particular, although the figures of this disclosure depict steps performed in a particular order for purposes of illustration and explanation, the methods of this disclosure are not limited to the specifically illustrated order or configuration. Various steps of the methods described above may be omitted, rearranged, combined, and / or adjusted in various ways without departing from the scope of this disclosure.

[0050] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art. Furthermore, it will be understood that terms commonly defined in dictionaries should be interpreted as having the same meaning in the context of the relevant art, rather than being interpreted in an idealized or overly formalized sense, unless expressly defined herein.

[0051] The foregoing is a description of the present disclosure and should not be construed as limiting the disclosure. While several exemplary embodiments of the present disclosure have been described, those skilled in the art will readily appreciate that many modifications may be made to the exemplary embodiments without departing from the novel teachings and advantages of the present disclosure. Accordingly, it is intended that all such modifications be included within the scope of the present disclosure as defined by the claims. It will be understood that the foregoing is a description of the present disclosure and should not be construed as limited to the particular embodiments disclosed, and that, in addition, modifications to the disclosed embodiments and other embodiments are intended to be included within the scope of the appended claims. The present disclosure is defined by the claims and their equivalents.

Claims

1. 1. A power conversion system comprising: a DC power supply for providing a first DC voltage; an inverter module for converting the first DC voltage to a first AC voltage; a power conversion module for converting the first DC voltage to a second AC voltage or for converting a third AC voltage external to the power conversion system to the second DC voltage; a first stage filter circuit connected between a first pair of terminals of the DC power supply and a second pair of terminals of the inverter module, the first stage filter circuit being used to remove noise signals having frequencies within a first frequency interval and a second frequency interval; a second stage filter circuit connected between a third pair of terminals of the first stage filter circuit and a fourth pair of terminals of the power conversion module, the second stage filter circuit being used to remove noise signals having frequencies within the second frequency interval, the second frequency interval being different from the first frequency interval.

2. 2. The power conversion system of claim 1, wherein switching of switching devices within the inverter module causes noise signals having frequencies within the first frequency interval and within the second frequency interval, and switching of switching devices associated with the power conversion module causes noise signals having frequencies within the first frequency interval and within the second frequency interval.

3. The power conversion system according to claim 1 , wherein a maximum value of the first frequency interval is equal to or less than a minimum value of the second frequency interval.

4. The power conversion system according to claim 3 , wherein the first frequency interval is equal to or greater than 100 kHz and equal to or less than 30 MHz, and the second frequency interval is equal to or greater than 30 MHz.

5. 2. The power conversion system of claim 1, wherein the first-stage filter circuit and the second-stage filter circuit are electromagnetic interference prevention filter circuits, each including at least one X capacitor, at least one Y capacitor, and at least one inductor.

6. The number of at least one of the X capacitors, the Y capacitors, or the inductors in the second-stage filter circuit is smaller than the number of at least one of the X capacitors, the Y capacitors, or the inductors in the first-stage filter circuit; or 6. The power conversion system of claim 5, wherein a parameter value of at least one of the X capacitor, the Y capacitor, or the inductor in the second-stage filter circuit is smaller than a parameter value corresponding to at least one of the X capacitor, the Y capacitor, or the inductor in the first-stage filter circuit.

7. The power conversion system of claim 6 , wherein the first stage filter circuit includes two common mode inductors and the second stage filter circuit includes one common mode inductor.

8. the first stage filter circuit includes a first common mode inductor, a second common mode inductor, a first X capacitor, and a second X capacitor, two pins of the first common mode inductor connected to the first pair of terminals of the DC power supply, other two pins of the first common mode inductor connected to both ends of the first X capacitor, two pins of the second common mode inductor connected to both ends of the first X capacitor, other two pins of the second common mode inductor connected to both ends of the second X capacitor, both ends of the second X capacitor connected to the second pair of terminals of the inverter module; 8. The power conversion system according to claim 5, wherein the second-stage filter circuit includes a third common mode inductor, a third X capacitor, and a fourth X capacitor, two pins of the third common mode inductor are connected to both ends of the second X capacitor, other two pins of the third common mode inductor are connected to both ends of the third X capacitor, the third X capacitor is connected in parallel to the fourth X capacitor, and both ends of the fourth X capacitor are connected to the fourth pair of terminals of the power conversion module.

9. 2. The power conversion system of claim 1, further comprising a DC voltage conversion module, wherein the DC voltage conversion module is used to convert the second DC voltage to a third DC voltage suitable for powering a component to be powered.

10. The power conversion system of claim 9 , wherein the DC voltage conversion module is integrated with the power conversion module.

11. The power conversion system of claim 1 , wherein the second DC voltage is further used to charge the DC power source.

12. A vehicle, A vehicle comprising the power conversion system according to any one of claims 1 to 11.

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