High-voltage auxiliary power supply unit, power supply system and vehicle

Abstract

The utility model relates to the technical field of power electronics, and discloses a high-voltage auxiliary power supply unit, a power supply system and a vehicle. The high-voltage auxiliary power supply unit comprises a one-way conduction circuit, a main control circuit and a high-voltage auxiliary power supply transformer which are connected in series, wherein the conduction direction of the one-way conduction circuit is opposite to the input current direction of a primary winding of the high-voltage auxiliary power supply transformer. According to the power conversion circuit, the current in the high-voltage auxiliary power supply unit is controlled to flow only in one direction by setting the one-way conduction circuit, so that a follow current path is prevented from being formed in the high-voltage auxiliary power supply unit when follow current exists in the power conversion circuit, and the control accuracy of the power conversion circuit is ensured.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and in particular to a high-voltage auxiliary power supply unit, a power supply system, and a vehicle. Background Technology

[0002] With the development of vehicle technology and an increasing emphasis on user experience, more and more electrical modules or devices with various functions are being added. This has highlighted the problem of insufficient power supply capacity from low-voltage batteries, leading to the addition of high-voltage auxiliary power supplies in vehicles. However, in current high-voltage auxiliary power supplies, when the power conversion circuit acts as a freewheeling circuit, a freewheeling loop is created on the high-voltage auxiliary power supply side, thus affecting the operation of electrical equipment. Utility Model Content

[0003] In view of this, this application proposes a high-voltage auxiliary power supply unit, a power supply system, and a vehicle to solve the problem that when the power conversion circuit in the existing high-voltage auxiliary power supply acts as a freewheeling circuit, a freewheeling loop will be generated on the high-voltage auxiliary power supply side.

[0004] The first aspect of this application provides a high-voltage auxiliary power supply unit, comprising: a unidirectional conduction circuit, a main control circuit, and a high-voltage auxiliary power supply transformer connected in series, wherein the conduction direction of the unidirectional conduction circuit is opposite to the direction of the input current of the primary winding of the high-voltage auxiliary power supply transformer.

[0005] In one feasible implementation, the unidirectional conduction circuit includes an uncontrollable semiconductor device, the anode of which is connected to the input terminal of the high-voltage auxiliary power transformer, and the cathode of which is connected to the output terminal of the main control circuit.

[0006] In one feasible implementation, the unidirectional conduction circuit includes a fully controllable semiconductor device and a driving circuit. The output terminal of the driving circuit is connected to the control terminal of the fully controllable semiconductor device, the input terminal of the fully controllable semiconductor device is connected to the input terminal of the high-voltage auxiliary power transformer, and the output terminal of the fully controllable semiconductor device is connected to the output terminal of the main control circuit.

[0007] In one feasible implementation, the circuit further includes a first current detection circuit, which is located between the output terminal of the unidirectional conduction circuit and the input terminal of the main control circuit.

[0008] In one feasible implementation, the system further includes a second current detection circuit, which is connected to the output of the main control circuit.

[0009] In one feasible implementation, a drive unit is further included, which is connected to the control terminal of the main control circuit and is used to control the on and off of the main control circuit.

[0010] In one feasible implementation, the drive unit is also connected to the control terminal of the unidirectional conduction circuit.

[0011] In one feasible implementation, it further includes at least one secondary-side switching circuit, each of which is connected in parallel with one of the secondary windings of the high-voltage auxiliary power transformer.

[0012] A second aspect of this application provides a power supply system, comprising: a high-voltage power supply unit, a high-voltage auxiliary power supply unit as described above, and a power conversion unit, wherein the high-voltage power supply unit and the power conversion unit are respectively connected to the high-voltage auxiliary power supply unit.

[0013] A third aspect of this application provides a vehicle including a power supply system as described above and at least one electrical device disposed on the secondary winding side of the high-voltage auxiliary power transformer.

[0014] The technical solution provided in this application includes a high-voltage auxiliary power supply unit comprising: a unidirectional conducting circuit, a main control circuit, and a high-voltage auxiliary power supply transformer connected in series. The conduction direction of the unidirectional conducting circuit is opposite to the direction of the input current in the primary winding of the high-voltage auxiliary power supply transformer. This application, by setting a unidirectional conducting circuit, controls the current in the high-voltage auxiliary power supply unit to flow only in one direction, thereby blocking the formation of a freewheeling path in the high-voltage auxiliary power supply unit when freewheeling exists in the power conversion circuit, thus ensuring the control accuracy of the power conversion circuit. Attached Figure Description

[0015] Figure 1 This is a first schematic diagram of a high-voltage auxiliary power supply unit provided in an embodiment of this application;

[0016] Figure 2 This is a second schematic diagram of a high-voltage auxiliary power supply unit provided in an embodiment of this application;

[0017] Figure 3 This is a third schematic diagram of a high-voltage auxiliary power supply unit provided in an embodiment of this application;

[0018] Figure 4 A circuit schematic diagram of a high-voltage auxiliary power supply unit provided in an embodiment of this application;

[0019] Figure 5 A schematic diagram of the power supply system provided in the embodiments of this application;

[0020] Figure 6 This is a schematic diagram of a vehicle provided in an embodiment of this application. Detailed Implementation

[0021] This application provides a high-voltage auxiliary power supply unit, a power supply system, and a vehicle. The main solution is to add a unidirectional conduction circuit to the existing high-voltage auxiliary power supply circuit. This unidirectional conduction circuit prevents current from flowing back into the transformer in the high-voltage auxiliary power supply circuit, thereby preventing the formation of a freewheeling path on the transformer and effectively solving the problem of failure of related components in the high-voltage auxiliary circuit.

[0022] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a particular order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0023] like Figure 1 As shown in the embodiment of this application, a power supply module is provided, which includes a high-voltage power supply unit 110, a power conversion unit 120, and a high-voltage auxiliary power supply unit 130; wherein, the power conversion unit 120 and the high-voltage auxiliary power supply unit 130 are connected in parallel with the high-voltage power supply unit 110, that is, it can be understood that the positive and negative terminals of the power conversion unit 120 and the high-voltage auxiliary power supply unit 130 are respectively connected to the positive and negative terminals of the high-voltage power supply unit 110.

[0024] It should be noted that the high-voltage power supply unit 110 includes a power supply Uin and an input capacitor Cin, which are connected in parallel. The power conversion unit 120 is connected in parallel with the power supply, and during operation, the power conversion unit 120 draws voltage from the power supply. The high-voltage auxiliary power supply unit 130 draws power from the input capacitor to provide operating voltage for other electrical equipment.

[0025] like Figure 1 As shown in the embodiment of this application, a high-voltage auxiliary power supply unit is provided. The high-voltage auxiliary power supply unit includes a unidirectional conduction circuit 131, a main control circuit 132, and a high-voltage auxiliary power transformer 133 connected in series. The conduction direction of the unidirectional conduction circuit 131 is opposite to the direction of the input current of the primary winding of the high-voltage auxiliary power transformer 133.

[0026] It should be noted that the two input terminals of the high-voltage auxiliary power transformer 133 are connected to the two output terminals of the power conversion unit. For example, the positive and negative buses of the power conversion unit are respectively connected to the two input terminals of the high-voltage auxiliary power transformer 133. When one input terminal of the high-voltage auxiliary power transformer 133 is connected to the negative bus, it is connected through a unidirectional conduction circuit 131. A main control circuit 132 is also provided between the unidirectional conduction circuit 131 and the negative bus. The conduction of the unidirectional conduction circuit 131 and the main control circuit 132 determines the connection between the input terminal of the high-voltage auxiliary power transformer 133 and the negative bus. The unidirectional conduction circuit 131 is used to control the unidirectional flow of current, thereby blocking the formation of a freewheeling path on the transformer.

[0027] In this embodiment, the high-voltage auxiliary power supply unit further includes a current detection circuit 134; the unidirectional conduction circuit 131, the main control circuit 132, and the current detection circuit 134 are connected in series to form a unidirectional current path, and the unidirectional current path is connected in series with the high-voltage auxiliary power supply transformer 133; as Figure 2 As shown, the specific location of the current detection circuit 134 can be at the output terminal of the main control circuit 132 (corresponding to the second current detection circuit), or it can be between the unidirectional conduction circuit 131 and the main control circuit 132 (corresponding to the first current detection circuit).

[0028] Understandably, the high-voltage auxiliary power transformer 133 includes a primary winding and a secondary winding. The primary winding has a first input terminal and a second input terminal. A unidirectional current path can be connected in series at either the first or the second input terminal. In this application, it is preferred to connect it in series at the second input terminal; that is, one end of the unidirectional current path is connected to the second input terminal, and the other end is connected to the negative terminal in the high-voltage power supply unit. It should be noted that the connection method of the unidirectional current path at the first and second input terminals is the opposite of that at the second input terminal.

[0029] Specifically, the input terminal of the unidirectional conduction circuit 131 is connected to the second input terminal of the high-voltage auxiliary power transformer 133, the output terminal of the unidirectional conduction circuit 131 is connected to the input terminal of the main control circuit 132, and the output terminal of the main control circuit 132 is connected to the current detection circuit 134. The unidirectional conduction circuit 131 is used to form a unidirectional current path between the high-voltage auxiliary power transformer 133 and the main control circuit 132. The current direction of this unidirectional current path can only be the direction in which the current flows out from the second input terminal of the primary winding.

[0030] The unidirectional conduction circuit 131 is used to form a unidirectional current channel between the high-voltage auxiliary power transformer 133 and the main control circuit 132, thereby blocking the influence of the power conversion unit on the high-voltage auxiliary power unit in freewheeling mode.

[0031] In this embodiment, the main control circuit 132 includes a first power switching device. The drain of the first power switching device is connected to the output terminal of the unidirectional conduction circuit 131, and the source of the first power switching device is connected to the current detection circuit 134. It should be noted that the main control circuit 132 is not limited to using a single first power switching device; it can also be implemented using multiple first power switching devices connected in series and parallel. The body diode in the first power switching device will have current flowing through it when there is freewheeling current in the power conversion unit, and this current enters the high-voltage auxiliary power transformer 133. Here, the blocking is achieved by adding a guiding conduction circuit 131.

[0032] In this embodiment, the unidirectional conduction circuit 131 is located between the input terminal of the main control circuit 132 and the input terminal of the high-voltage auxiliary power transformer 133. Alternatively, it can be located between the output terminal of the main control circuit 132 and the current detection circuit 134, or between the current detection circuit 134 and the negative terminal of the high-voltage power supply unit.

[0033] By implementing the power module provided above, a unidirectional conduction circuit is added to block the freewheeling path in the high-voltage auxiliary power transformer, thereby forming a unidirectional current path. This solves the problem of failure of related devices in the high-voltage auxiliary power unit when there is freewheeling and the freewheeling current exceeds the device's tolerance.

[0034] In one feasible implementation, the unidirectional conduction circuit 131 includes an uncontrollable semiconductor device 1311, the anode of which is connected to the input terminal of the high-voltage auxiliary power transformer 133, and the cathode of which is connected to the output terminal of the main control circuit 132.

[0035] Furthermore, in addition to the uncontrollable semiconductor device 1311, the guiding and conducting circuit 131 may also include a voltage divider circuit to achieve voltage division and protect the uncontrollable semiconductor device 1311; the uncontrollable semiconductor device 1311 is connected in series with the voltage divider circuit and is located between the input terminal of the high-voltage auxiliary power transformer 133 and the drain of the first power switching device, such as... Figure 2 As shown.

[0036] It should be noted that the uncontrollable semiconductor device 1311 is a high-voltage diode. The anode of the high-voltage diode is connected to the input terminal of the high-voltage auxiliary power transformer 133, and the cathode of the high-voltage diode is connected to the drain of the first power switching device. In practical applications, the unidirectional conduction circuit 131 can be designed using at least one high-voltage diode, specifically selected according to the actual voltage drop requirements. When multiple high-voltage diodes are selected, they should be connected in series in the same direction, i.e., the anode and cathode are connected sequentially in series.

[0037] like Figure 4 As shown, the main control circuit 132 is a MOSFET Q7, the current detection circuit 134 is a resistor R, the unidirectional conduction circuit 131 is a high-voltage diode D, and the high-voltage auxiliary power transformer T draws power from the input capacitor Cin. In this full-bridge topology, when one of the power transistors Q2, Q4, and Q6 in the lower bridge acts as a freewheeling transistor, the freewheeling current it generates is blocked by the high-voltage diode D between the three-dimensional primary winding of the high-voltage auxiliary power transformer T and the drain (D) of the MOSFET Q7.

[0038] By setting this high-voltage diode D, it mainly plays three roles in the circuit. First, when the high-voltage power supply is reverse-connected to the positive and negative terminals of the equipment, the high-voltage diode provides reverse protection, thus protecting both the high-voltage power supply and related components of the high-voltage auxiliary power supply. Second, when any of the power transistors Q2, Q4, and Q6 in the lower bridge of the three-phase full-bridge is in freewheeling mode during normal switching, the high-voltage diode D blocks the freewheeling circuit composed of the high-voltage auxiliary power supply current sensing resistor R, the body diode of MOSFET Q7, and the input winding of transformer T, effectively solving the problem of failure of related components of the high-voltage auxiliary power supply. Third, the high-voltage diode D blocks the closed loop formed by the primary winding of the high-voltage auxiliary power supply transformer, the body diode of MOSFET Q7, the current sensing resistor R, and the three-phase winding of the motor, preventing the high-voltage auxiliary power supply from negatively affecting the precise control of the motor.

[0039] In another embodiment, the unidirectional conduction circuit 131 includes a fully controllable semiconductor device 1312 and a drive circuit 1313. The output terminal of the drive circuit 1313 is connected to the control terminal of the fully controllable semiconductor device 1312, the input terminal of the fully controllable semiconductor device 1312 is connected to the input terminal of the high-voltage auxiliary power transformer 133, and the output terminal of the fully controllable semiconductor device 1312 is connected to the output terminal of the main control circuit 132. The drive circuit 1313 is used to drive the fully controllable semiconductor device 1312 to conduct, forming a unidirectional current path with the first power switching device and the current detection circuit 134, such as... Figure 3As shown. It should be noted that the fully controllable semiconductor device 1312 is a second power switch device, and the body diode of the second power switch device must be connected in reverse to the body diode of the first power switch device, and the drive circuit 1313 ensures that it does not conduct in freewheeling mode.

[0040] The high-voltage auxiliary power supply unit also includes a drive unit 140, which is connected to the control terminal of the main control circuit 132 and used to control the on and off of the main control circuit 132 to achieve charging and discharging control of the high-voltage auxiliary power supply transformer 133. In practical applications, the drive unit 140 can be configured to share a controller with the drive circuit 1313, that is, the drive unit 140 and the drive circuit 1313 are one unit. This can further reduce the cost of the circuit while still achieving the corresponding control.

[0041] In another feasible embodiment, the high-voltage auxiliary power supply unit further includes at least one secondary-side conversion circuit, each of the secondary-side conversion circuits being connected in parallel with a secondary winding of the high-voltage auxiliary power supply transformer 133.

[0042] By implementing this embodiment, a unidirectional conduction circuit is added to the high-voltage auxiliary power supply transformer. When the power supply is reversed with the positive and negative terminals of the equipment, the high-voltage diode plays a reverse protection role. This protects both the high-voltage power supply and the related components of the high-voltage auxiliary power supply unit. It also effectively blocks the freewheeling circuit composed of the current sensing resistor R, the body diode of the MOSFET Q7, and the input winding of the transformer T. This effectively solves the problem of failure of related components of the high-voltage auxiliary power supply and prevents the high-voltage auxiliary power supply from having a negative impact on the precise control of the motor.

[0043] This application also provides a power supply system, including: a high-voltage power supply unit 110, a high-voltage auxiliary power supply unit 130 as provided in the above embodiments, and a power conversion unit 120, wherein the high-voltage power supply unit 110 and the power conversion unit 120 are respectively connected to the high-voltage auxiliary power supply unit 130, as shown in the above embodiments. Figure 5 As shown.

[0044] Understandably, the power conversion unit 110 includes a bridge circuit and a load, which can be a motor, electrical equipment, etc. In a car, the load is the motor. The bridge circuit is a three-phase full-bridge circuit, such as an upper and lower bridge circuit composed of six power switching transistors (Q1-6). The motor is a three-phase motor. Figure 4 As shown.

[0045] This application also provides a vehicle, including a power supply system 510 as provided in the above embodiments and at least one electrical device 520, wherein the electrical device 520 is disposed on the secondary winding side of the high-voltage auxiliary power transformer, such as... Figure 6 As shown.

[0046] Finally, it should be noted that the above embodiments are merely specific implementations of this application, used to illustrate the technical solutions of this application, and not to limit them. The protection scope of this application is not limited thereto. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the technical scope disclosed in this application. Such modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be covered within the protection scope of this application. Therefore, the protection scope of this application should be determined by the protection scope of the claims.

Claims

1. A high-voltage auxiliary power supply unit, characterized in that, include: A unidirectional conducting circuit, a main control circuit, and a high-voltage auxiliary power transformer are connected in series, wherein the conduction direction of the unidirectional conducting circuit is opposite to the direction of the input current in the primary winding of the high-voltage auxiliary power transformer.

2. The high-voltage auxiliary power supply unit according to claim 1, characterized in that, The unidirectional conduction circuit includes an uncontrollable semiconductor device, the anode of which is connected to the input terminal of the high-voltage auxiliary power transformer, and the cathode of which is connected to the output terminal of the main control circuit.

3. The high-voltage auxiliary power supply unit according to claim 1, characterized in that, The unidirectional conduction circuit includes a fully controllable semiconductor device and a driving circuit. The output terminal of the driving circuit is connected to the control terminal of the fully controllable semiconductor device, the input terminal of the fully controllable semiconductor device is connected to the input terminal of the high-voltage auxiliary power transformer, and the output terminal of the fully controllable semiconductor device is connected to the output terminal of the main control circuit.

4. The high-voltage auxiliary power supply unit according to claim 1, characterized in that, Also includes: A first current detection circuit is located between the output terminal of the unidirectional conduction circuit and the input terminal of the main control circuit.

5. The high-voltage auxiliary power supply unit according to claim 1, characterized in that, Also includes: The second current detection circuit is connected to the output terminal of the main control circuit.

6. The high-voltage auxiliary power supply unit according to any one of claims 1-5, characterized in that, It also includes a drive unit, which is connected to the control terminal of the main control circuit and is used to control the on and off of the main control circuit.

7. The high-voltage auxiliary power supply unit according to claim 6, characterized in that, The drive unit is also connected to the control terminal of the unidirectional conduction circuit.

8. The high-voltage auxiliary power supply unit according to any one of claims 1-5, characterized in that, It also includes at least one secondary-side switching circuit, each of which is connected in parallel with one of the secondary windings of the high-voltage auxiliary power transformer.

9. A power supply system, characterized in that, include: The high-voltage power supply unit, the high-voltage auxiliary power supply unit as described in any one of claims 1-8, and the power conversion unit are respectively connected to the high-voltage auxiliary power supply unit.

10. A vehicle, characterized in that, It includes the power supply system as described in claim 9 and at least one electrical device, wherein the electrical device is located on the secondary winding side of the high-voltage auxiliary power transformer.

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