Low-power consumption transformer, emergency power supply circuit and motor controller

Abstract

The application provides a low-power-consumption transformer, an emergency power supply circuit and a motor controller, and is used for solving the MOS tube switching loss problem caused by the interlayer capacitance of the transformer in the emergency power supply of a new energy automobile. The low-power-consumption transformer comprises at least five layers of circuit boards arranged at intervals, a magnetic core penetrating through the circuit, a primary winding and a secondary winding, wherein the primary winding is composed of an excitation winding and an auxiliary winding in a nested structure, and the secondary winding wholly wraps the primary winding. The small size and high power density are realized by integrating the planar magnetic core through the multilayer circuit board, the electric field distribution is optimized by using the nested winding, the interlayer parasitic capacitance is significantly inhibited, the switching loss of the MOS tube is reduced, the power consumption of the transformer is reduced, and the safety and energy efficiency are effectively improved.

Description

Technical Field

[0001] This invention relates to the field of new energy vehicles, and in particular to a low-power transformer, an emergency power supply circuit, and a motor controller. Background Technology

[0002] In the motor controller and emergency power circuit of new energy vehicles, the transformer, as the core component of energy conversion, undertakes the function of converting high-voltage DC to low-voltage DC. Specifically, the emergency power circuit is usually integrated into the motor controller. When the main power supply system fails, it draws power from the high-voltage battery through the low-power transformer, and after DC / DC conversion, provides emergency power to critical loads (such as the braking control system and safety sensors) to ensure the controllable operation of the vehicle under safe conditions.

[0003] However, interlayer capacitance can cause significant switching losses in MOSFETs: at the moment of MOSFET turn-on, the sudden change in drain-source voltage generates a current spike through the transformer's distributed capacitance. This current flows through the drive circuit impedance, forming a voltage spike. If the amplitude or duration of the spike exceeds the detection threshold of the power control chip, it will induce the power chip to misidentify the spike as a short circuit or overcurrent fault, leading to false power protection. Simultaneously, the energy stored in the interlayer capacitance is released at the moment of switching, increasing not only the conduction losses and stress of the switching devices but also reducing system stability through electromagnetic interference (EMI). Especially in high-voltage platforms of new energy vehicles (such as 800V systems), the higher system operating voltage further increases the charging and discharging energy of the transformer winding's distributed capacitance. In emergency power supply circuits using planar transformers, compared to traditional frame transformers, the introduction of planar windings leads to an increase in inter-winding distributed capacitance, making the MOSFET loss problem even more prominent.

[0004] Therefore, there is currently no good solution to this problem. Summary of the Invention

[0005] In order to overcome the above-mentioned technical defects, the purpose of this invention is to provide a low-power transformer, an emergency power supply circuit, and a motor controller.

[0006] This invention discloses a low-power transformer, comprising: at least five layers of circuit boards, a magnetic core, a primary winding, and a secondary winding.

[0007] Among them, at least five circuit boards are arranged at intervals along the first direction.

[0008] The magnetic core extends along a first direction and passes through at least five layers of circuit boards in sequence.

[0009] The primary winding includes an excitation winding and an auxiliary winding. The excitation winding is wound on at least two of the at least five layers of the circuit board and encloses the auxiliary winding.

[0010] The secondary winding is wound on two of the at least five circuit boards and encloses the primary winding.

[0011] Preferably, the at least five-layer circuit board specifically includes a first layer, a second layer, a third layer, a fourth layer, a fifth layer, and a sixth layer.

[0012] The excitation winding occupies the second, fourth, and fifth layers. After the portions of the excitation winding in the fourth and fifth layers are connected in parallel, they are connected to the portion in the second layer.

[0013] The auxiliary winding occupies the third layer. The secondary winding occupies the first and sixth layers.

[0014] Preferably, the excitation winding is wound from the outside to the inside in the second layer and connected to the fourth and fifth layers through the first hole. The excitation winding is wound from the inside to the outside in the fourth and fifth layers.

[0015] The secondary winding is wound from the outside in on the first layer and connected to the sixth layer through the second hole. The secondary winding is wound from the inside out on the sixth layer.

[0016] Preferably, at least five layers of circuit boards are solid insulating circuit boards, and at least five layers of circuit boards form electrical isolation between the magnetic core and the primary winding and the secondary winding.

[0017] Preferably, the magnetic core includes a first portion, a second portion, and a third portion extending along a first direction. Both the primary winding and the secondary winding are wound around the first portion, and the second and third portions are located on opposite sides of the primary winding and the secondary winding, respectively.

[0018] The projections of the primary winding and the secondary winding onto a plane perpendicular to the first direction overlap.

[0019] Preferably, the excitation winding and auxiliary winding are high-voltage windings, and the secondary winding is a low-voltage winding.

[0020] In a plane perpendicular to the first direction, the distance between the excitation winding and the magnetic core is greater than 0.6 mm, the distance between the auxiliary winding and the magnetic core is greater than 1.5 mm, and the distance between the secondary winding and the magnetic core is greater than 0.4 mm.

[0021] Preferably, the auxiliary winding is a monitoring winding or a demagnetizing winding.

[0022] A second aspect of this application provides an emergency power supply circuit, which includes an input circuit, an output circuit, and a low-power transformer as described in any of the foregoing embodiments. The input circuit is electrically connected to the output circuit via the low-power transformer.

[0023] A third aspect of this application provides a motor controller, including the aforementioned emergency power supply circuit.

[0024] Compared with existing technologies, the above technical solution has the following advantages: 1. This solution utilizes a multi-layer PCB board integrated planar magnetic core transformer structure, significantly improving power density and miniaturization compared to traditional frame transformers, meeting the space-constrained emergency power supply layout requirements of new energy vehicles. Furthermore, by nesting auxiliary windings within the excitation windings, the interlayer distance of the excitation windings is increased, effectively optimizing the distributed capacitance between them. At the moment the MOSFET turns on, the sudden change in drain-source voltage generates a current spike through the transformer's distributed capacitance. This current flows through the drive circuit impedance, forming a voltage spike. If the amplitude or duration of the spike exceeds the detection threshold of the power control chip, it will induce the power chip to misidentify the spike as a short circuit or overcurrent fault, leading to false power protection. Therefore, by increasing the interlayer distance of the excitation windings, the interlayer capacitance is reduced, thereby lowering the amplitude of the voltage spike and preventing false power protection, thus increasing the overall vehicle safety and stability. Moreover, current spikes also cause MOSFET losses. Therefore, by reducing the current spike band, the switching losses and electromagnetic interference of the MOSFET are also reduced. It is particularly suitable for emergency power supply scenarios with high-frequency switching under 800V high-voltage platforms, improving safety performance and transformer efficiency. On the other hand, the interlayer distance of the excitation winding is not wasted, but is used as an auxiliary winding. The auxiliary winding can be set as various expandable functional windings, which further improves the design flexibility of the transformer and the space utilization of the transformer, thus making the transformer structure compact and suitable for emergency power supply scenarios.

[0025] 2. By setting up two layers of excitation windings in parallel, the internal resistance of the windings at this point can be effectively reduced, thereby avoiding heat generation and energy loss. Furthermore, the auxiliary winding can be configured as either a monitoring winding or a demagnetizing winding. When the auxiliary winding is a monitoring winding, the output voltage and power supply operating status can be adjusted in real time based on the monitoring winding, enabling fault protection and restart. When the auxiliary winding is a demagnetizing winding, the transformer can be in the form of a forward topology. The demagnetizing winding allows the transformer's magnetism to quickly reset after excitation, achieving periodicity and avoiding magnetic saturation.

[0026] 3. By using a solid insulating circuit board as the winding carrier, an insulating layer is constructed between the magnetic core and the winding. Based on this insulating layer, the distance between the first hole and the second hole, as well as the distance between the high-voltage winding and the low-voltage winding, are appropriately set to ensure the insulation between the first hole and the second hole, as well as the insulation between the high-voltage winding and the low-voltage winding. This improves safety and stability while further miniaturizing the transformer.

[0027] 4. After integrating this low-power transformer into the emergency power supply circuit, its low-loss characteristics ensure the continuous power supply capability of critical loads (such as the electronic braking system) when the main power supply fails. Further embedding it into the motor controller forms a highly reliable safety power protection system for new energy vehicles, thereby greatly enhancing the overall vehicle safety performance. Attached Figure Description

[0028] Figure 1 A front view schematic diagram of the low-power transformer provided in this application; Figure 2 A top view of the low-power transformer provided in this application; Figure 3 This is a schematic diagram of the structure of the first layer of the low-power transformer provided in this application; Figure 4 This is a schematic diagram of the second layer of the low-power transformer provided in this application; Figure 5 A schematic diagram of the third layer of the low-power transformer provided in this application; Figure 6 A schematic diagram of the fourth layer of the low-power transformer provided in this application; Figure 7 A schematic diagram of the fifth layer of the low-power transformer provided in this application; Figure 8 A schematic diagram of the sixth layer of the low-power transformer provided in this application; Figure 9 A schematic diagram of the emergency power supply circuit provided in this application.

[0029] Figure label: 100, low-power transformer; 1. Primary winding; 11. First hole; 2. Excitation winding; 3. Auxiliary winding; 4. Secondary winding; 41. Second hole; 6. Magnetic core; 61. First part; 62. Second part; 63. Third part; 71. First floor; 72. Second floor; 73. Third floor; 74. Fourth floor; 75. Fifth floor; 76. Sixth floor; z, First direction. Detailed Implementation

[0030] The advantages of the present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments.

[0031] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0032] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The singular forms “a,” “the,” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0033] It should be understood that although the terms first, second, third, etc., may be used in this disclosure to describe various information, such information should not be limited to these terms. These terms are used only to distinguish information of the same type from one another. For example, without departing from the scope of this disclosure, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if," as used herein, can be interpreted as "when," "in response to determination," or "when," or "in the event of a determination." In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0034] In the description of this invention, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two components. They can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0035] In the following description, suffixes such as "module," "part," or "unit" used to denote elements are used only for the convenience of the description of the invention and have no specific meaning in themselves. Therefore, "module" and "part" can be used interchangeably.

[0036] Please see Figures 1-2 , Figure 1 for Figure 1 A front view schematic diagram of the low-power transformer provided in this application; Figure 2 This is a top view of the low-power transformer provided in this application.

[0037] like Figures 1-2 As shown, the present invention discloses a low-power transformer 100, comprising: at least five layers of circuit boards, a magnetic core 6, a primary winding 1, and a secondary winding 4.

[0038] Among them, at least five circuit boards are arranged at intervals along the first direction z.

[0039] The magnetic core 6 extends along the first direction z and passes through at least five circuit boards in sequence.

[0040] The primary winding 1 includes an excitation winding 2 and an auxiliary winding 3; the excitation winding 2 is wound on at least two of the at least five layers of circuit boards and encloses the auxiliary winding 3 within it; The secondary winding 4 is wound on two of the at least five layers of circuit boards and encloses the primary winding 1.

[0041] Those skilled in the art will understand that the auxiliary winding 3, inserted between the excitation windings 2 as an electromagnetic field control element, weakens the concentration of the electric field between the layers of the primary winding 1 by changing the potential gradient distribution between adjacent conductive layers. The reduction in electric field strength directly leads to a decrease in interlayer parasitic capacitance. Furthermore, the introduction of the auxiliary winding 3 physically segments the direct capacitive coupling path between the layers of the primary winding 1. By inserting the auxiliary winding 3 into intermediate layers with different potentials, the single large capacitance path is decomposed into multiple small capacitors connected in series, thereby reducing the total equivalent capacitance, which in turn reduces the switching losses of the MOSFET and optimizes the power consumption performance of the transformer.

[0042] Therefore, this solution utilizes a multi-layer PCB board integrated planar magnetic core transformer structure, which significantly improves power density and miniaturization compared to traditional skeleton transformers, meeting the space-constrained emergency power supply layout requirements of new energy vehicles. Furthermore, by nesting auxiliary windings within the excitation windings, the interlayer distance of the excitation windings is increased, effectively optimizing the distributed capacitance between them. At the moment the MOSFET turns on, the sudden change in drain-source voltage generates a current spike through the transformer's distributed capacitance. This current flows through the drive circuit impedance, forming a voltage spike. If the amplitude or duration of the spike exceeds the detection threshold of the power control chip, it will induce the power chip to misidentify the spike as a short circuit or overcurrent fault, leading to false power protection. Therefore, by increasing the interlayer distance of the excitation windings, the interlayer capacitance is reduced, thereby lowering the amplitude of the voltage spike and preventing false power protection, thus increasing the overall vehicle safety and stability. Moreover, current spikes also cause MOSFET losses. Therefore, by reducing the current spike band, the switching losses and electromagnetic interference of the MOSFET are also reduced. It is particularly suitable for emergency power supply scenarios with high-frequency switching under 800V high-voltage platforms, improving safety performance and transformer efficiency. On the other hand, the interlayer distance of the excitation winding is not wasted, but is used as an auxiliary winding. The auxiliary winding can be set as various expandable functional windings, which further improves the design flexibility of the transformer and the space utilization of the transformer, thus making the transformer structure compact and suitable for emergency power supply scenarios.

[0043] The above is an explanation of the basic concept of this application. The following will describe in detail the specific structure of each component of the transformer with reference to the accompanying drawings.

[0044] Please see Figures 3-8 , Figure 3 This is a schematic diagram of the structure of the first layer of the low-power transformer provided in this application; Figure 4 This is a schematic diagram of the second layer of the low-power transformer provided in this application; Figure 5 A schematic diagram of the third layer of the low-power transformer provided in this application; Figure 6 A schematic diagram of the fourth layer of the low-power transformer provided in this application; Figure 7 A schematic diagram of the fifth layer of the low-power transformer provided in this application; Figure 8 This is a schematic diagram of the sixth layer of the low-power transformer provided in this application.

[0045] First, the low-power transformer 100 may or may not include a specific number of circuit board layers.

[0046] like Figures 3-8 As shown, combined with Figure 1 and Figure 2It is understood that, in one possible implementation, at least five layers of circuit board specifically include a first layer 71, a second layer 72, a third layer 73, a fourth layer 74, a fifth layer 75, and a sixth layer 76.

[0047] Among them, the excitation winding 2 occupies the second layer 72, the fourth layer 74 and the fifth layer 75; after the excitation winding 2 is partially connected in parallel in the fourth layer 74 and the fifth layer 75, it is connected to the part in the second layer 72. Auxiliary winding 3 occupies the third layer 73; secondary winding 4 occupies the first layer 71 and the sixth layer 76.

[0048] This can be understood as follows: the excitation winding 2 occupies three circuit board layers. The portion in the fourth layer (74) and the portion in the fifth layer (75) are connected in parallel, and then connected to the portion in the second layer (72). This configuration allows for lower internal resistance in the winding, further optimizing energy consumption.

[0049] In another possible implementation, the at least five-layer circuit board may also include more or fewer circuit board structures, which is not limited here.

[0050] Furthermore, the excitation winding 2 and the auxiliary winding 3 are high-voltage windings; the secondary winding 4 is a low-voltage winding.

[0051] The specific winding method of the excitation winding 2 and the secondary winding 4 is not limited. The excitation winding 2 is wound from the outside to the inside in the second layer 72, and reaches the fourth layer 74 and the fifth layer 75 through the first hole 11, and is wound from the inside to the outside in the fourth layer 74 and the fifth layer 75; The secondary winding 4 is wound from the outside to the inside in the first layer 71, and reaches the sixth layer 76 through the second hole 41, and is wound from the inside to the outside in the sixth layer 76.

[0052] Furthermore, the specific type of circuit board is not limited. In one possible implementation, at least five layers of circuit boards are solid-insulated circuit boards, and at least five layers of circuit boards form electrical isolation between the magnetic core 6 and the primary winding 1 and the secondary winding 4.

[0053] The magnetic core 6 includes a first part 61, a second part 62 and a third part 63 extending along the first direction z; the primary winding 1 and the secondary winding 4 are both wound around the first part 61, and the second part 62 and the third part 63 are located on the outside of the primary winding 1 and the secondary winding 4 respectively. The projections of the primary winding 1 and the secondary winding 4 onto a plane perpendicular to the first direction z overlap.

[0054] By setting the circuit board as a solid-insulated circuit board, electrical isolation is formed between the magnetic core 6 and the primary winding 1 and the secondary winding 4, ensuring safety performance. Therefore, the distance between the components can be further shortened, thereby further realizing the high density of the low-power transformer 100. Furthermore, by staggering the projection of the windings in the first direction z, the interlayer capacitance can be further reduced, further optimizing energy consumption performance.

[0055] Based on this, the distance between each winding can be further designed to further miniaturize the low-power transformer 100.

[0056] In one possible implementation, on a plane perpendicular to the first direction z, the distance between the excitation winding 2 and the magnetic core 6 is greater than 0.6 mm, the distance between the auxiliary winding 3 and the magnetic core 6 is greater than 1.5 mm, and the distance between the secondary winding 4 and the magnetic core 6 is greater than 0.4 mm.

[0057] Based on this insulation layer, the distance between the first hole 11 and the second hole 41, as well as the distance between the excitation winding 2, the auxiliary winding 3 and the secondary winding 4, are appropriately set to ensure the insulation between the excitation winding 2, the auxiliary winding 3 and the secondary winding 4 between the first hole 11 and the second hole 41. While improving safety and stability, the low-power transformer 100 is further miniaturized.

[0058] Finally, those skilled in the art will understand that the specific type of auxiliary winding 3 is also not limited. In one possible implementation, auxiliary winding 3 is a monitoring winding or a demagnetizing winding.

[0059] When auxiliary winding 3 is a monitoring winding, the output voltage and power supply operating status can be adjusted in real time based on the monitoring winding 3, enabling fault protection and restart. When auxiliary winding 3 is a demagnetizing winding, the transformer can be in the form of a forward topology. The demagnetizing winding allows the transformer's magnetism to quickly reset after excitation, achieving periodicity and avoiding magnetic saturation. Ultimately, this achieves optimal comprehensive performance in terms of safety, efficiency, and EMC within a compact transformer layout.

[0060] The above is a detailed structural description of the low-power transformer 100 provided in this application. An exemplary embodiment will be given below to further facilitate understanding by those skilled in the art: like Figures 1-8 As shown, in one possible implementation, the low-power transformer 100 is 24 mm long, 37.2 mm wide, and 6.6 mm high. The excitation winding 2 has an inductance of 290 uH; the auxiliary winding 3 has an inductance of 8 uH; and the secondary winding 4 has an inductance of 13 uH. The turns ratio of the excitation winding 2, auxiliary winding 3, and secondary winding 4 is 24:4:5. The inter-turn capacitance of the excitation winding 2 is 5.93 pF, and the primary-secondary coupling capacitance is 67.7 pF. Please refer to [link to relevant documentation]. Figure 9 , Figure 9A schematic diagram of the emergency power supply circuit provided in this application.

[0061] like Figure 9 As shown, a second aspect of this application provides an emergency power supply circuit, which includes an input circuit, an output circuit, and a low-power transformer 100 as described in any of the foregoing embodiments. The input circuit is electrically connected to the output circuit via the low-power transformer 100.

[0062] After integrating this low-power transformer into the emergency power supply circuit, its low-loss characteristics ensure the continuous power supply capability of critical loads (such as electronic braking systems) when the main power supply fails.

[0063] A third aspect of this application provides a motor controller including the aforementioned emergency power supply circuit. By applying the aforementioned emergency power supply circuit to the motor controller, a highly reliable safety power protection system for new energy vehicles can be formed, thereby greatly enhancing the overall vehicle safety performance.

[0064] It should be noted that the embodiments of the present invention have better implementability and are not intended to limit the present invention in any way. Any person skilled in the art may use the above-disclosed technical content to change or modify it into equivalent effective embodiments. However, any modifications or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A low-power transformer, characterized in that, include: At least five layers of circuit boards, magnetic core, primary winding, and secondary winding; The at least five circuit boards are arranged at intervals along the first direction; The magnetic core extends along the first direction and passes through the at least five layers of circuit boards in sequence; The primary winding includes an excitation winding and an auxiliary winding; the excitation winding is wound on at least two of the at least five circuit boards and encloses the auxiliary winding. The secondary winding is wound around two of the at least five circuit boards and encloses the primary winding. The at least five-layer circuit board includes a first layer, a second layer, a third layer, a fourth layer, a fifth layer, and a sixth layer; The excitation winding occupies the second layer, the fourth layer, and the fifth layer; the excitation winding is connected in parallel in portions of the fourth and fifth layers, and then connected to the portion in the second layer. The auxiliary winding occupies the third layer; the secondary winding occupies the first layer and the sixth layer.

2. The low-power transformer as described in claim 1, characterized in that, The excitation winding is wound from the outside to the inside in the second layer and is connected to the fourth and fifth layers through the first hole; the excitation winding is wound from the inside to the outside in the fourth and fifth layers. The secondary winding is wound from the outside to the inside in the first layer and connected to the sixth layer through the second hole; the secondary winding is wound from the inside to the outside in the sixth layer.

3. The low-power transformer as described in claim 2, characterized in that, The at least five-layer circuit board is a solid insulating circuit board, and the at least five-layer circuit board forms electrical isolation between the magnetic core and the primary winding and the secondary winding.

4. The low-power transformer as described in claim 3, characterized in that, The magnetic core includes a first part, a second part, and a third part extending along the first direction; the primary winding and the secondary winding are both wound around the first part, and the second part and the third part are located on both sides of the primary winding and the secondary winding, respectively; The projections of the primary winding and the secondary winding on a plane perpendicular to the first direction overlap.

5. The low-power transformer as described in claim 3, characterized in that, The excitation winding and the auxiliary winding are high-voltage windings; the secondary winding is a low-voltage winding. On a plane perpendicular to the first direction, the distance between the excitation winding and the magnetic core is greater than 0.6 mm, the distance between the auxiliary winding and the magnetic core is greater than 1.5 mm, and the distance between the secondary winding and the magnetic core is greater than 0.4 mm.

6. The low-power transformer as described in claim 5, characterized in that, The auxiliary winding is a monitoring winding or a demagnetizing winding.

7. An emergency power supply circuit, characterized in that, The emergency power supply circuit includes an input circuit, an output circuit, and a low-power transformer as described in any one of claims 1-6; the input circuit is electrically connected to the output circuit through the low-power transformer.

8. A motor controller, characterized in that, Includes the emergency power supply circuit as described in claim 7.

Images