Power converter and charging pile
By connecting the auxiliary edge of the transformer of the first rectifier network in the power converter, the magnetic coupling is achieved, and the magnetic coupling is achieved, and the traditional LLC parallel component's device flow problem is solved, and the reliability of the product is improved.
Patent Information
- Application Number
- CN202420571919.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-21
- Publication Date
- 2025-01-24
- Estimated Expiration
- 2034-03-21
AI Technical Summary
Traditional LLC parallel connection is difficult to solve the device current sharing problem caused by inconsistent device parameters, affecting product reliability.
By connecting the auxiliary edge of the transformer in the first rectifier network and the auxiliary edge of the transformer in the second rectifier network, the magnetic coupling combination between the first rectifier network and the second rectifier network is realized, thereby achieving the balance of each device.
It effectively solves the device current sharing problem caused by inconsistent device parameters and improves the reliability of the product during use.
Smart Images
Figure CN222395571U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of power electronics, and in particular to a power converter and a charging pile. Background Art
[0002] The three-phase LLC resonant circuit is often used in high-power DC-DC converter topologies. In the three-phase LLC resonant circuit, any two-phase switch tubes work 120 degrees apart, which can achieve balanced power distribution and reduce input and output current ripples.
[0003] However, in order to meet the needs of supercharging, the processing power of the DC-DC converter needs to be improved. Relying on traditional LLC parallel connection is difficult to solve the device current sharing problem caused by inconsistent device parameters, which will greatly affect product reliability in actual use. Utility Model Content
[0004] Based on the above problems, the utility model provides a power converter and a charging pile to solve the problem of device current sharing caused by inconsistent device parameters.
[0005] In a first aspect, an embodiment of the utility model provides a power converter, including: a first resonant converter and a second resonant converter; the first resonant converter includes a first switch network, a first resonant network and a first rectifier network, and the second resonant converter includes a second switch network, a second resonant network and a second rectifier network; the first rectifier network includes a first transformer secondary side, a second transformer secondary side, a third transformer secondary side and a first rectifier circuit, and the second rectifier network includes a fourth transformer secondary side, a fifth transformer secondary side, a sixth transformer secondary side and a second rectifier circuit;
[0006] The output end of the first switch network is connected to the input end of the first resonant network, and the output end of the first resonant network is connected to the input end of the first rectifier network; the output end of the second switch network is connected to the input end of the second resonant network, and the output end of the second resonant network is connected to the input end of the second rectifier network;
[0007] In the first rectifier network and the second rectifier network, the secondary sides of the first transformer, the second transformer and the sixth transformer are connected in star shape and connected to the first rectifier circuit; the secondary sides of the third transformer, the fourth transformer and the fifth transformer are connected in star shape and connected to the second rectifier circuit.
[0008] Optionally, the first resonant network is composed of a first resonant circuit, a second resonant circuit and a third resonant circuit, and the second resonant network is composed of a fourth resonant circuit, a fifth resonant circuit and a sixth resonant circuit; the first resonant circuit includes a first capacitor, a first inductor and a first transformer primary, the second resonant circuit includes a second capacitor, a second inductor and a second transformer primary, the third resonant circuit includes a third capacitor, a third inductor and a third transformer primary, the fourth resonant circuit includes a fourth capacitor, a fourth inductor and a fourth transformer primary, the fifth resonant circuit includes a fifth capacitor, a fifth inductor and a fifth transformer primary, and the sixth resonant circuit includes a sixth capacitor, a sixth inductor and a sixth transformer primary.
[0009] Optionally, the first transformer primary, the second transformer primary and the third transformer primary are connected in a star shape; the fourth transformer primary, the fifth transformer primary and the sixth transformer primary are connected in a star shape.
[0010] Optionally, one end of the secondary side of the first transformer is respectively connected to one end of the secondary side of the second transformer and one end of the secondary side of the sixth transformer; the other end of the secondary side of the first transformer, the other end of the secondary side of the second transformer and the other end of the secondary side of the sixth transformer are respectively connected to the first rectifier circuit; one end of the secondary side of the third transformer is respectively connected to one end of the secondary side of the fourth transformer and one end of the secondary side of the fifth transformer; the other end of the secondary side of the third transformer, the other end of the secondary side of the fourth transformer and the other end of the secondary side of the fifth transformer are respectively connected to the second rectifier circuit.
[0011] Optionally, one end of the primary side of the first transformer is respectively connected to one end of the primary side of the second transformer and one end of the primary side of the third transformer; the other end of the primary side of the first transformer, the other end of the primary side of the second transformer and the other end of the primary side of the sixth transformer are respectively connected to the first branch of the first capacitor and the first inductor connected in series, the second branch of the second capacitor and the second inductor connected in series, and the third branch of the third capacitor and the third inductor connected in series; one end of the primary side of the fourth transformer is respectively connected to one end of the primary side of the fifth transformer and one end of the primary side of the sixth transformer; the other end of the primary side of the fourth transformer, the other end of the primary side of the fifth transformer and the other end of the primary side of the sixth transformer are respectively connected to the fourth branch of the fourth capacitor and the fourth inductor connected in series, the fifth branch of the fifth capacitor and the fifth inductor connected in series, and the sixth branch of the sixth capacitor and the sixth inductor connected in series.
[0012] Optionally, both the first switch network and the second switch network are three-phase two-level bridge circuits or three-phase three-level bridge circuits;
[0013] Each phase of the three-phase two-level bridge circuit or the three-phase three-level bridge circuit in the first switching network is respectively connected to the first resonant circuit, the second resonant circuit and the third resonant circuit; each phase of the three-phase two-level bridge circuit or the three-phase three-level bridge circuit in the second switching network is respectively connected to the fourth resonant circuit, the fifth resonant circuit and the sixth resonant circuit.
[0014] Optionally, both the first rectifier circuit and the second rectifier circuit are three-phase bridge rectifier circuits;
[0015] One end of the secondary side of the first transformer, one end of the secondary side of the second transformer, and one end of the secondary side of the sixth transformer are respectively connected to each phase in the first rectifier circuit; one end of the secondary side of the third transformer, one end of the secondary side of the fourth transformer, and one end of the secondary side of the fifth transformer are respectively connected to each phase in the first rectifier circuit.
[0016] Optionally, it also includes: a filtering circuit;
[0017] An input end of the filter circuit is connected to an output end of the first rectifier circuit and an output end of the second rectifier circuit, and an output end of the filter circuit is connected to a load.
[0018] Optionally, the first rectifier circuit and the second rectifier circuit are coupled to each other.
[0019] In a second aspect, an embodiment of the utility model provides a charging pile, which includes a power converter as described in any one of the aforementioned embodiments.
[0020] The resonant converter described in the embodiment of the utility model is composed of a first resonant converter and a second resonant converter; the first resonant converter includes a first switch network, a first resonant network and a first rectifier network, and the second resonant converter includes a second switch network, a second resonant network and a second rectifier network; the first rectifier network includes a first transformer secondary side, a second transformer secondary side, a third transformer secondary side and a first rectifier circuit, and the second rectifier network includes a fourth transformer secondary side, a fifth transformer secondary side, a sixth transformer secondary side and a second rectifier circuit. Among them, the first transformer secondary side, the second transformer secondary side and the sixth transformer secondary side are star-connected and connected to the first rectifier circuit; the third transformer secondary side, the fourth transformer secondary side and the fifth transformer secondary side are star-connected and connected to the second rectifier circuit. In the embodiment of the utility model, by star-connecting the transformer secondary side (the first transformer secondary side, the second transformer secondary side and the third transformer secondary side) in the first rectifier network with the transformer secondary side (the fourth transformer secondary side, the fifth transformer secondary side and the sixth transformer secondary side) in the second rectifier network, the transformer in the first rectifier network is magnetically coupled with the transformer in the second rectifier network, thereby achieving current sharing of each device. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.
[0022] Figure 1 A schematic diagram of the structure of a resonant converter provided in an embodiment of the utility model;
[0023] Figure 2 A schematic diagram of the structure of another resonant converter provided by an embodiment of the utility model;
[0024] Figure 3 A schematic diagram of the structure of another resonant converter provided in an embodiment of the utility model. DETAILED DESCRIPTION
[0025] The problem of current sharing of devices is easy to occur in high-power resonant converters. To this end, in the embodiment of the utility model, the secondary side of the transformer in the first resonant converter is coupled with the secondary side of the transformer in the second resonant converter and connected in a star shape, so that the first resonant converter and the second resonant converter are magnetically coupled, thereby achieving current sharing of each device.
[0026] See also Figure 1 , which is a schematic diagram of the structure of a power converter provided in an embodiment of the utility model.
[0027] like Figure 1 As shown, the power converter includes: a first resonant converter and a second resonant converter; the first resonant converter includes a first switch network 101, a first resonant network 102 and a first rectifier network 103, and the second resonant converter includes a second switch network 104, a second resonant network 105 and a second rectifier network 106; the first rectifier network 103 includes a first transformer secondary side Ns1, a second transformer secondary side Ns2, a third transformer secondary side Ns3 and a first rectifier circuit, and the second rectifier network 106 includes a fourth transformer secondary side Ns4, a fifth transformer secondary side Ns5, a sixth transformer secondary side Ns6 and a second rectifier circuit.
[0028] Among them, the first transformer secondary Ns1, the second transformer secondary Ns2 and the sixth transformer secondary Ns3 are connected in star shape and connected to the first rectifier circuit; the third transformer secondary Ns4, the fourth transformer secondary Ns5 and the fifth transformer secondary Ns6 are connected in star shape and connected to the second rectifier circuit.
[0029] like Figure 1As shown, the first transformer T1, the second transformer T2, the third transformer T3, the fourth transformer T4, the fifth transformer T5 and the sixth transformer T6 in the embodiment of the utility model are connected in parallel, and the connection method is star connection. After the star connection, the first resonant converter and the second resonant converter are magnetically coupled, thereby achieving current sharing of each device, thereby improving the reliability of the product during use.
[0030] In an optional embodiment, the first resonant network 102 is composed of a first resonant circuit, a second resonant circuit and a third resonant circuit, and the second resonant network 105 is composed of a fourth resonant circuit, a fifth resonant circuit and a sixth resonant circuit; the first resonant circuit includes a first capacitor Cr1, a first inductor L1 and a first transformer primary Np1, the second resonant circuit includes a second capacitor Cr2, a second inductor L2 and a second transformer primary Np2, the third resonant circuit includes a third capacitor Cr3, a third inductor L3 and a third transformer primary Np3, the fourth resonant circuit includes a fourth capacitor Cr4, a fourth inductor L4 and a fourth transformer primary Np4, the fifth resonant circuit includes a fifth capacitor Cr5, a fifth inductor L5 and a fifth transformer primary Np5, and the sixth resonant circuit includes a sixth capacitor Cr6, a sixth inductor L6 and a sixth transformer primary Np6.
[0031] As an example, the first transformer primary Np1, the second transformer primary Np2 and the third transformer primary Np3 are connected in star shape; the fourth transformer primary Np4, the fifth transformer primary Np5 and the sixth transformer primary Np6 are connected in star shape. The specific connection method is as follows: Figure 2 shown.
[0032] The star connection of transformer refers to connecting one terminal of each phase winding in the three-phase winding of the transformer together to form a common terminal, and the other terminal is connected to a power line to form a three-phase four-wire circuit. There are three main advantages: First, in the star connection, the voltage between the two terminals of the three-phase winding is small, so the current is also small. This is because the voltage of the three-phase power supply differs by 120°, the symmetry is good, and the current is not easy to concentrate on a certain line, thereby reducing the loss and tightness of the line; second, in the star connection, the power supply and the load are grounded separately, and no large phase voltage will be generated, reducing the loss of the line; third, in the star connection, each midpoint of the three-phase winding can be directly grounded, which is convenient for the grounding of the system.
[0033] In the related art, two inductors (not the primary or secondary side of the transformer) and a capacitor are used to form a resonant circuit. In the embodiment of the utility model, the primary inductor of the transformer is used as one of the inductors constituting the resonant circuit, which can simplify the structure of the resonant circuit and reduce the practical use of the inductor, thereby reducing the mention of the power converter and reducing the cost of the power converter.
[0034] In addition, for ease of understanding, the present utility model embodiment provides another structural schematic diagram of a power converter, such as Figure 3 shown.
[0035] exist Figure 3 In the embodiment, one end of the first transformer secondary side Ns1 is respectively connected to one end of the second transformer secondary side Ns2 and one end of the sixth transformer secondary side Ns6; the other end of the first transformer secondary side Ns1, the other end of the second transformer secondary side Ns2 and the other end of the sixth transformer secondary side Ns6 are respectively connected to the first rectifier circuit; one end of the third transformer secondary side Ns3 is respectively connected to one end of the fourth transformer secondary side Ns4 and one end of the fifth transformer secondary side Ns5; the other end of the third transformer secondary side Ns3, the other end of the fourth transformer secondary side Ns4 and the other end of the fifth transformer secondary side Ns5 are respectively connected to the second rectifier circuit.
[0036] One end of the first transformer primary Np1 is respectively connected to one end of the second transformer primary Np2 and one end of the third transformer primary Np3; the other end of the first transformer primary Np1, the other end of the second transformer primary Np2 and the other end of the third transformer primary Np3 are respectively connected to the first branch of the first capacitor and the first inductor connected in series, the second branch of the second capacitor and the second inductor connected in series, and the third branch of the third capacitor and the third inductor connected in series; one end of the fourth transformer primary Np4 is respectively connected to one end of the fifth transformer primary Np5 and one end of the sixth transformer primary Np6; the other end of the fourth transformer primary Np4, the other end of the fifth transformer primary Np5 and the other end of the sixth transformer primary Np6 are respectively connected to the fourth branch of the fourth capacitor and the fourth inductor connected in series, the fifth branch of the fifth capacitor and the fifth inductor connected in series, and the sixth branch of the sixth capacitor and the sixth inductor connected in series.
[0037] In addition, the first switch network 101 and the second switch network 104 may also be a three-phase two-level bridge circuit or a three-phase three-level bridge circuit.
[0038] Each phase of the three-phase two-level bridge circuit or the three-phase three-level bridge circuit in the first switch network 101 is connected to the first resonant circuit, the second resonant circuit and the third resonant circuit respectively; each phase of the three-phase two-level bridge circuit or the three-phase three-level bridge circuit in the second switch network 104 is connected to the fourth resonant circuit, the fifth resonant circuit and the sixth resonant circuit respectively.
[0039] In addition, both the first rectifier circuit and the second rectifier circuit can be three-phase bridge rectifier circuits, and the first rectifier circuit is coupled to the second rectifier circuit. One end of the first transformer secondary side Ns1, one end of the second transformer secondary side Ns2, and one end of the sixth transformer secondary side Ns6 are respectively connected to each phase in the first rectifier circuit; one end of the third transformer secondary side Ns3, one end of the fourth transformer secondary side Ns4, and one end of the fifth transformer secondary side Ns5 are respectively connected to each phase in the first rectifier circuit.
[0040] As an example, the first transformer secondary Ns1 is connected to the midpoint of the first rectifier circuit DA1 and DA4, the second transformer secondary Ns2 is connected to the midpoint of the first rectifier circuit DA2 and DA5, and the sixth transformer secondary Ns6 is connected to the midpoint of DA3 and DA6; the fourth transformer secondary Ns4 is connected to the midpoint of the second rectifier circuit DB1 and DB4, the fourth transformer secondary Ns4 is connected to the midpoint of the second rectifier circuit DB2 and DB5, and the fifth transformer secondary Ns5 is connected to the midpoint of DB3 and DB6.
[0041] In addition, the embodiment of the utility model also includes a filter circuit, wherein the types of the filter circuit include but are not limited to a capacitor filter circuit, an inductor filter circuit, a gamma filter circuit, a π-type LC filter circuit, and a π-type RC filter circuit.
[0042] In the above-mentioned embodiment, the adopted power source may be a main DC bus.
[0043] In addition to the power converter, an embodiment of the utility model further provides a charging pile, which includes the power converter described in any of the above embodiments.
[0044] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.
[0045] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A power converter, characterized in that: include: A first resonant converter and a second resonant converter; the first resonant converter includes a first switch network, a first resonant network and a first rectifier network, and the second resonant converter includes a second switch network, a second resonant network and a second rectifier network; the first rectifier network includes a first transformer secondary side, a second transformer secondary side, a third transformer secondary side and a first rectifier circuit, and the second rectifier network includes a fourth transformer secondary side, a fifth transformer secondary side, a sixth transformer secondary side and a second rectifier circuit; The output end of the first switch network is connected to the input end of the first resonant network, and the output end of the first resonant network is connected to the input end of the first rectifier network; the output end of the second switch network is connected to the input end of the second resonant network, and the output end of the second resonant network is connected to the input end of the second rectifier network; In the first rectifier network and the second rectifier network, the secondary sides of the first transformer, the second transformer and the sixth transformer are connected in star shape and connected to the first rectifier circuit; the secondary sides of the third transformer, the fourth transformer and the fifth transformer are connected in star shape and connected to the second rectifier circuit.
2. The power converter according to claim 1, characterized in that: The first resonant network is composed of a first resonant circuit, a second resonant circuit and a third resonant circuit, and the second resonant network is composed of a fourth resonant circuit, a fifth resonant circuit and a sixth resonant circuit; the first resonant circuit includes a first capacitor, a first inductor and a first transformer primary, the second resonant circuit includes a second capacitor, a second inductor and a second transformer primary, the third resonant circuit includes a third capacitor, a third inductor and a third transformer primary, the fourth resonant circuit includes a fourth capacitor, a fourth inductor and a fourth transformer primary, the fifth resonant circuit includes a fifth capacitor, a fifth inductor and a fifth transformer primary, and the sixth resonant circuit includes a sixth capacitor, a sixth inductor and a sixth transformer primary.
3. The power converter according to claim 2, characterized in that: The first transformer primary, the second transformer primary and the third transformer primary are connected in a star shape; the fourth transformer primary, the fifth transformer primary and the sixth transformer primary are connected in a star shape.
4. The power converter according to claim 2 or 3, characterized in that: One end of the secondary side of the first transformer is respectively connected to one end of the secondary side of the second transformer and one end of the secondary side of the sixth transformer; the other end of the secondary side of the first transformer, the other end of the secondary side of the second transformer and the other end of the secondary side of the sixth transformer are respectively connected to the first rectifier circuit; One end of the secondary side of the third transformer is respectively connected to one end of the secondary side of the fourth transformer and one end of the secondary side of the fifth transformer; the other end of the secondary side of the third transformer, the other end of the secondary side of the fourth transformer and the other end of the secondary side of the fifth transformer are respectively connected to the second rectifier circuit.
5. The power converter according to claim 4, characterized in that: One end of the primary side of the first transformer is respectively connected to one end of the primary side of the second transformer and one end of the primary side of the third transformer; the other end of the primary side of the first transformer, the other end of the primary side of the second transformer and the other end of the primary side of the third transformer are respectively connected to the first branch of the first capacitor and the first inductor connected in series, the second branch of the second capacitor and the second inductor connected in series, and the third branch of the third capacitor and the third inductor connected in series; one end of the primary side of the fourth transformer is respectively connected to one end of the primary side of the fifth transformer and one end of the primary side of the sixth transformer; the other end of the primary side of the fourth transformer, the other end of the primary side of the fifth transformer and the other end of the primary side of the sixth transformer are respectively connected to the fourth branch of the fourth capacitor and the fourth inductor connected in series, the fifth branch of the fifth capacitor and the fifth inductor connected in series, and the sixth branch of the sixth capacitor and the sixth inductor connected in series.
6. The power converter according to claim 5, characterized in that: The first switch network and the second switch network are both three-phase two-level bridge circuits or three-phase three-level bridge circuits; Each phase of the three-phase two-level bridge circuit or the three-phase three-level bridge circuit in the first switching network is respectively connected to the first resonant circuit, the second resonant circuit and the third resonant circuit; each phase of the three-phase two-level bridge circuit or the three-phase three-level bridge circuit in the second switching network is respectively connected to the fourth resonant circuit, the fifth resonant circuit and the sixth resonant circuit.
7. The power converter according to claim 6, characterized in that: The first rectifier circuit and the second rectifier circuit are both three-phase bridge rectifier circuits; One end of the secondary side of the first transformer, one end of the secondary side of the second transformer and one end of the secondary side of the sixth transformer are respectively connected to each phase in the first rectifier circuit; One end of the secondary side of the third transformer, one end of the secondary side of the fourth transformer and one end of the secondary side of the fifth transformer are respectively connected to each phase in the first rectifier circuit.
8. The power converter according to claim 6, characterized in that: Also includes: Filter circuit; An input end of the filter circuit is connected to an output end of the first rectifier circuit and an output end of the second rectifier circuit, and an output end of the filter circuit is connected to a load.
9. The power converter according to claim 6, characterized in that: The first rectifier circuit and the second rectifier circuit are coupled to each other.
10. A charging pile, characterized in that: The charging pile comprises a power converter as described in any one of claims 1-9.