Coupling enhancement type modular SiC MOSFET ringing suppression resonator, manufacturing method and energy conversion system

Abstract

The invention discloses a coupling enhancement type modular SiC MOSFET ringing suppression resonator, a manufacturing method and an energy conversion system. The resonator comprises at least one PCB resonance unit, and the PCB resonance unit is arranged at a PT symmetric singular point of an external conductive path. The PCB resonance unit comprises a PCB and an RLC resonance circuit; the self-inductance is obtained according to the preset size parameter of the spiral inductance coil, the matching capacitance of the capacitor and the resistance value of the resistor are obtained through the self-inductance, then the PCB resonance units are manufactured according to the obtained parameters, the PCB resonance units are arranged on the outer side of a conductive path of an external main circuit, and the resonator is obtained. The resonator is simple in design and structure, and ringing generated at the switching moment of the SiC MOSFET can be effectively restrained under the conditions that switching loss is not increased and the switching speed of the SiC MOSFET is not reduced.

Description

Technical Field

[0001] The present invention belongs to the field of power electronic devices, and in particular relates to a coupling-enhanced modular SiC MOSFET ringing suppression resonator, a manufacturing method and an energy conversion system. Background Art

[0002] With the rapid development of power electronics technology, semiconductor devices are increasingly used in efficient energy conversion systems. SiC MOSFET performs well in high power density applications due to its high switching speed, low conduction loss, high temperature resistance and high current density, and has gradually become the first choice for high-performance power electronics systems. However, while these superior characteristics of SiC MOSFET bring efficient energy conversion, they also cause significant electromagnetic interference (EMI) problems, especially the parasitic inductance and capacitance in the circuit and device package at the switching moment, which are affected by high dv / dt and di / dt during high-speed switching to form an LC resonant circuit and exchange energy, resulting in severe high-frequency oscillations at the switching moment, namely ringing. This high-frequency oscillation will not only increase the EMI of the system, but may also affect the reliability of the device and lead to potential failure risks.

[0003] Traditionally, adding suppression measures on the drive side and power circuit can achieve the effect of ringing suppression, but these methods often have significant limitations. The design of buffer circuits and damping resistors will increase the complexity of additional components and power loss, and will inevitably reduce the switching speed; the optimization of circuit layout is limited by the space and process constraints in practical applications, and is not flexible enough in practical applications, making it difficult to adapt to the needs of different systems. As for the external coupling damping circuit, because it is electrically isolated from the main circuit and does not increase the design difficulty of the main circuit, it has the advantage of high reliability and has attracted widespread attention from scholars at home and abroad in recent years. However, the existing design of external damping circuits for ringing suppression also has problems such as large size, high cost, and low integration, which makes it difficult to meet the requirements of modern electronic equipment for high efficiency, miniaturization and high performance. Therefore, how to solve the limitations of traditional external coupling damping circuits and effectively suppress ringing has become a technical problem that needs to be solved urgently. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention proposes a coupled enhanced modular SiC MOSFET ringing suppression resonator, a manufacturing method and an energy conversion system. The present invention aims to solve the problems of large size, low integration, complex design, slow switching speed and additional switching loss in the existing ringing suppression technology. The resonator of the present invention is small in size and can effectively suppress the ringing phenomenon generated at the switching moment without affecting the fast switching characteristics of SiC MOSFET and without introducing additional power loss.

[0005] The technical solution of the present invention is as follows:

[0006] 1. A modular SiC MOSFET ringing suppression resonator with enhanced coupling

[0007] The resonator is arranged radially outside the conductive path in the external main circuit, and the resonator includes at least one PCB resonance unit, and each PCB resonance unit is arranged at a PT symmetric singular point of the external conductive path.

[0008] The PCB resonance unit comprises a PCB board and an RLC resonance circuit arranged on the PCB board, wherein the RLC resonance circuit is mainly composed of a spiral inductor coil, a capacitor and a resistor connected in series.

[0009] In each PCB resonance unit, the resonance frequency of the RLC resonance circuit is equal to the resonance frequency of the external main circuit, that is, the external main circuit and the RLC resonance circuit in each PCB resonance unit satisfy the following relationship:

[0010] ω1=ω2=ω0

[0011] Wherein, ω1 is the resonant frequency of the external main circuit; ω2 is the resonant frequency of the RLC resonant circuit in each PCB resonant unit of the resonator loop, and ω0 is the natural angular frequency of the system.

[0012] Furthermore, each PCB resonant unit and the external main circuit satisfy the following relationship:

[0013] γ2-γ1=2k

[0014] In the formula, γ1 is the damping rate of the external main circuit to which the conductive path belongs, γ2 is the damping rate of the PCB resonance unit, and κ is the coupling rate between the PCB resonance unit and the external main circuit.

[0015] The resonant frequency ω1 of the external main circuit can be calculated by the following formula:

[0016]

[0017] Where, L1 is the sum of the stray inductance of the external main circuit and the total parasitic inductance of the power circuit; C oss is the output capacitance of the SiC MOSFET in the external main circuit.

[0018] Among them, in each PCB resonant unit, the natural resonant frequency ω2 of the RLC resonant circuit can be calculated by the following formula:

[0019]

[0020] Where L2 is the self-inductance of the spiral inductor in the RLC resonant circuit, and C2 is the matching capacitance of the capacitor in the RLC resonant circuit.

[0021] In the RLC resonant circuit of each PCB resonant unit, the resistance value R2 of the resistor and the self-inductance L2 of the spiral inductor coil satisfy the following relationship:

[0022] R2=2L2(ω0k+γ1)

[0023] Where, R2 is the resistance of the resistor in the RLC resonant circuit, L2 is the self-inductance of the spiral inductor in the RLC resonant circuit, k is the coupling coefficient between the PCB resonant unit and the external main circuit, and γ1 is the damping rate of the external main circuit to which the conductive path belongs;

[0024] In the RLC resonant circuit of each PCB resonant unit, the matching capacitance C2 of the capacitor and the self-inductance L2 of the spiral inductor coil satisfy the following relationship:

[0025]

[0026] Where C2 is the matching capacitance of the capacitor in the RLC resonant circuit, f1 is the ringing frequency of the external main circuit SiCMOSFET to which the conductive path belongs, and L2 is the self-inductance of the spiral inductor in the RLC resonant circuit.

[0027] Specifically, the magnetic flux lines in the magnetic field generated by the conductive path pass through the PCB resonance unit in a direction perpendicular to the PCB board surface in each PCB resonance unit; when the number of the PCB resonance units is greater than one, all the PCB resonance units are distributed circumferentially around the conductive path.

[0028] Specifically, the spiral inductor coil is provided on one side of the PCB board close to the conductive path. The spiral inductor coil adopts a double-layer planar spiral inductor structure. The double-layer planar spiral inductor structure is mainly composed of two layers of upper and lower planar spiral coils. The two layers of planar spiral coils have the same rotation direction, and the current directions in the two layers of planar spiral coils are the same.

[0029] Specifically, each planar spiral coil is formed by winding a conductive wire along a rectangular spiral path on the surface of its corresponding PCB board according to a preset number of turns and spacing, and each corner of the rectangular spiral path adopts a rounded transition.

[0030] The rectangular spiral path refers to a rectangular spiral shape, and the winding along the rectangular spiral path specifically means that the wire is spirally unfolded outward or inward layer by layer based on the side of the rectangle.

[0031] 2. A method for manufacturing a modular SiC MOSFET ringing suppression resonator

[0032] The manufacturing method comprises the following steps:

[0033] 1) According to the preset size parameters of the spiral inductor in the RLC resonant circuit, the self-inductance L2 of the spiral inductor is calculated;

[0034] 2) According to the self-inductance L2 of the spiral inductor in the RLC resonant circuit, the matching capacitance C2 of the capacitor and the resistance R2 of the resistor are calculated;

[0035] The matching capacitance C2 of the capacitor is calculated by the following formula:

[0036]

[0037] Where, C2 is the matching capacitance of the capacitor in the RLC resonant circuit, f1 is the ringing frequency of the external main circuit to which the conductive path belongs, and L2 is the self-inductance of the spiral inductor in the RLC resonant circuit;

[0038] The resistance value R2 of the resistor is calculated by the following formula:

[0039] R2=2L2(ω0k+γ1)

[0040] Among them, R2 is the resistance value of the resistor in the RLC resonant circuit, L2 is the self-inductance of the spiral inductor in the RLC resonant circuit, k is the coupling coefficient between the PCB resonant unit and the external main circuit, γ1 is the damping rate of the external main circuit to which the conductive path belongs, and ω0 is the natural angular frequency of the system;

[0041] 3) Determine the model of the capacitor and the model of the resistor according to the matching capacitance C2 of the capacitor and the resistance value R2 of the resistor, and obtain the capacitor and the resistor;

[0042] 4) According to the preset size parameters of the spiral inductor in the RLC resonant circuit, wiring is performed on a double-layer PCB board to obtain a spiral inductor, and the spiral inductor is connected in series with the capacitor and resistor obtained in step 3) to obtain a PCB resonant unit, and at least one PCB resonant unit is arranged outside the conductive path of the external main circuit, and all PCB resonant units outside the conductive path constitute the resonator.

[0043] The preset size parameters of the spiral inductor coil are obtained according to the space capacity at the conductive path in the external main circuit; the spiral inductor coil adopts a double-layer planar spiral inductor structure, and the double-layer planar spiral inductor structure is mainly composed of two planar spiral coils. The size parameters of the spiral inductor coil include one or more of the number of turns, spacing, width and thickness of the planar spiral coil.

[0044] The self-inductance L2 of the spiral inductor is calculated by the following formula:

[0045]

[0046] Where L2 is the self-inductance of the spiral inductor in the RLC resonant circuit, μ0 is the vacuum permeability, l is the total length of the coil, w is the coil wiring width, r is the coil wiring thickness, n is the number of coil turns, and M is the mutual inductance between the external main circuit and the PCB resonant unit.

[0047] Among them, the mutual inductance M between the external main circuit and the PCB resonant unit is calculated by the following formula:

[0048]

[0049] Where M is the mutual inductance between the external main circuit and the PCB resonant unit, μ0 is the vacuum magnetic permeability, l is the total length of the coil, is the average distance between each turn of wire.

[0050] 3. An energy conversion system

[0051] The energy conversion system adopts the above-mentioned modular SiC MOSFET ringing suppression resonator, including one or more of a power converter, an inverter and a drive circuit.

[0052] The resonator provided by the present invention obtains the optimal external parameters that can suppress the ringing phenomenon based on the PT symmetry principle, and has the advantages of simple structure, easy integration, low power consumption and high efficiency. It can effectively solve the problem of insufficient ringing phenomenon suppression in the prior art, and significantly improves the application performance of SiC MOSFET in high-frequency energy conversion systems. It has broad application prospects and market value.

[0053] The beneficial effects of the present invention are as follows:

[0054] 1. Based on the passive PT symmetry theory, the present invention arranges multiple PCB resonance units at the passive PT symmetry theory singular points of the conductive path in the main circuit to construct a passive discrete ringing suppression resonator; the resonator of the present invention can effectively suppress the ringing generated by the SiC MOSFET switch instantaneously without increasing the switching loss and reducing the switching speed of the SiC MOSFET.

[0055] 2. The present invention provides a method for customizing resonators according to the limited spatial capacity in a high-frequency energy conversion system, and can also flexibly control the number of superimposed resonators. It can not only flexibly adapt to different application requirements, but also greatly simplify the design and manufacturing process, and improve the compatibility and scalability of the system.

[0056] 3. The coupled inductor coil design provided by the present invention significantly improves the coupling degree with the main circuit while reducing the volume, thereby enhancing the suppression effect of the ringing phenomenon.

[0057] 4. The resonator of the present invention does not require complex active control circuits and additional power devices, which reduces the difficulty of design, manufacturing and implementation, reduces the volume and cost of the system, and significantly improves the flexibility of design and manufacturing and the stability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 It is a structural schematic diagram of the PCB resonance unit in the present invention;

[0059] Figure 2 It is a schematic diagram of the structure of the resonator in the present invention;

[0060] Figure 3 Schematic diagram of coupling between a resonator and a main circuit in an embodiment of the present invention;

[0061] Figure 4 Schematic diagram of the topology of the PCB resonant unit and the main circuit in an embodiment of the present invention;

[0062] Figure 5 1 is a comparison diagram of the ringing suppression effect in the embodiment of the present invention; (a) is before adding the resonator, and (b) is after adding the resonator;

[0063] Figure 6 V with different numbers of resonant units added in the embodiment of the present invention DS Comparison diagram; (a) is the MOSFET off state, (b) is the MOSFET on state. DETAILED DESCRIPTION

[0064] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in each embodiment of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0065] The present invention provides a coupling-enhanced modular SiC MOSFET ringing suppression resonator. The SiC MOSFET specifically refers to a silicon carbide-metal semiconductor field effect transistor. The resonator of the present invention is used to suppress the ringing phenomenon generated by the SiC MOSFET switch in a high-frequency energy conversion system.

[0066] The working principle of the resonator of the present invention is: at the moment of MOSFET turning off and turning on, serious ringing phenomenon occurs due to the resonance of parasitic inductance and capacitance. Through the principle of electromagnetic induction, the ringing energy is transmitted through the parasitic inductance in the double pulse test circuit. The spiral inductor coil in each resonant unit receives the ringing energy and generates an induced electromotive force, which is finally consumed by the resistor R2.

[0067] like Figure 2 As shown, the resonator of the present invention is arranged at intervals with the conductive path in the external main circuit. The resonator of the present invention includes at least one PCB resonance unit, each of which is arranged at a PT symmetric singular point of the conductive path. The PT symmetric singular point specifically refers to a Parity-Time (PT) symmetric singular point. Multiple PCB resonance units are arranged around to form an overall resonator structure.

[0068] In the resonator of the present invention, each PCB resonant unit is independent of each other and compactly arranged around the conductive path to form a modular resonator structure. This modular design not only enables the resonator to flexibly adapt to different application requirements, but also greatly simplifies the design and manufacturing process and improves the compatibility and scalability of the system.

[0069] The resonator of the present invention adopts a discrete passive design. The discrete structural design fundamentally cuts off the electrical connection with the main circuit, thereby increasing the safety of use. Specifically, each PCB resonance unit in the resonator of the present invention is a passive component, and each PCB resonance unit is independent of each other (the cross coupling between each PCB resonance unit is weak and can be ignored).

[0070] Each PCB resonant unit can form an energy exchange channel with the external main circuit through a spiral inductor, thereby effectively suppressing the ringing generated by the SiC MOSFET switch without increasing switching losses or reducing switching speed. Since faster switching speeds can significantly improve energy conversion efficiency, fast switching characteristics are particularly important in high-frequency applications, so the resonator of the present invention can be applied to a variety of high-frequency energy conversion systems.

[0071] By coupling the ringing energy in the main circuit to each discrete PCB resonant unit for consumption, the temperature surge of the main circuit can be avoided. In addition, the resonator of the present invention can freely adjust the number of PCB resonant units as needed, and by designing multiple PCB resonant units for superposition, it can not only achieve a higher ringing suppression effect, but also adapt to a variety of application scenarios.

[0072] like Figure 1As shown, the PCB resonance unit includes a PCB board and an RLC resonance circuit arranged on the PCB board. The RLC resonance circuit is used to capture and consume the ringing energy of the external main circuit (i.e., the main power circuit). The RLC resonance circuit is mainly composed of a spiral inductor, a capacitor, and a resistor connected in series. Among them, the spiral inductor is used to provide inductance and improve the coupling ability of the ringing suppression resonator; the capacitor is used to make the RLC resonance circuit loop resonate with the main circuit to further improve the degree of energy exchange; the resistor is used to consume the oscillation energy and achieve the ringing suppression effect. By adopting PCB technology to set the RLC resonance circuit on the PCB board, the resonator of the present invention has the advantages of small size, light weight and low cost, and can be easily integrated into various power electronic systems. In addition, PCB technology also makes the production process of the resonator simpler and more efficient, which is conducive to large-scale production and application promotion.

[0073] In the resonator of the present invention, the PCB resonant unit is parameterized based on the PT symmetry theory, using the unique properties of the non-Hermitian singular points (Exceptional points) of the PT symmetric system. Specifically, the parameter selection of the spiral inductor coil and capacitor in each discrete passive PCB resonant unit in the resonator of the present invention meets the following conditions: each PCB resonant unit is placed near the conductive path, the inductance value of the inductor and the capacitance value of the capacitor are set according to the ringing frequency of the SiC MOSFET in the main circuit, and the PT symmetry requirements are met between the external main circuit and the RLC resonant circuit loop, so that the RLC resonant circuit in the PCB resonant unit can effectively absorb and suppress the ringing energy at the switching moment.

[0074] Since the external main circuit and the RLC resonant circuit loop meet the PT symmetry requirements, each PCB resonant unit is arranged at the PT symmetry singular point of the conductive path. Therefore, each PCB resonant unit and the external main circuit meet the following relationship:

[0075] γ2-γ1=2κ

[0076] Among them, γ1 is the damping rate of the external main circuit to which the conductive path belongs, γ2 is the damping rate of the PCB resonance unit, and κ is the coupling rate between the PCB resonance unit and the external main circuit.

[0077] Among them, the damping rate γ1 of the external main circuit to which the conductive path belongs, the damping rate γ2 of the PCB resonant unit, and the coupling rate κ between the PCB resonant unit and the external main circuit are calculated by the following formulas:

[0078] γ1=R1 / 2L1

[0079] γ2=R2 / 2L2

[0080]

[0081] Where R1 is the parasitic resistance of the external loop, R2 is the resistance value of the resistor in the RLC resonant circuit, and M is the mutual inductance between the external main circuit and the PCB resonant unit.

[0082] Since the external main circuit and the RLC resonant circuit loop meet the PT symmetry requirements, the resonant frequency of the RLC resonant circuit in each PCB resonant unit is equal to the resonant frequency of the external main circuit. That is, the RLC resonant circuit in each PCB resonant unit and the external main circuit meet the following relationship:

[0083] ω1=ω2

[0084] Wherein, ω1 is the resonant frequency of the external main circuit; ω2 is the inherent resonant frequency of the RLC resonant circuit in each PCB resonant unit of the resonator loop.

[0085] Among them, the resonant frequency ω1 of the external main circuit can be calculated by the following formula:

[0086]

[0087] Where, L1 is the sum of the stray inductance of the external main circuit and the total parasitic inductance of the power circuit; C oss is the output capacitance of the SiC MOSFET in the external main circuit.

[0088] In each PCB resonant unit, the natural resonant frequency ω2 of the RLC resonant circuit can be calculated by the following formula:

[0089]

[0090] Wherein, L2 is the self-inductance of the spiral inductor in the RLC resonant circuit, and C2 is the matching capacitance of the capacitor in the RLC resonant circuit.

[0091] In the RLC resonant circuit of each PCB resonant unit, the resistance value R2 of the resistor and the self-inductance L2 of the spiral inductor coil satisfy the following relationship:

[0092] R2=2L2(ω0k+γ1)

[0093] Among them, R2 is the resistance of the resistor in the RLC resonant circuit, L2 is the self-inductance of the spiral inductor in the RLC resonant circuit, k is the coupling coefficient between the PCB resonant unit and the external main circuit, γ1 is the damping rate of the external main circuit to which the conductive path belongs, and ω0 is the natural angular frequency of the system.

[0094] In the RLC resonant circuit of each PCB resonant unit, the matching capacitance C2 of the capacitor and the self-inductance L2 of the spiral inductor coil satisfy the following relationship:

[0095]

[0096] Among them, C2 is the matching capacitance of the capacitor in the RLC resonant circuit, f1 is the ringing frequency of the external main circuit to which the conductive path belongs, and L2 is the self-inductance of the spiral inductor coil in the RLC resonant circuit.

[0097] The resonator of the present invention is used in various high-frequency energy conversion systems, including but not limited to power converters, inverters and drive circuits. Specifically, the external main circuit includes a double pulse test circuit, a SiC power module and a practical application integrated circuit, etc.; the components of the external main circuit include SiC MOSFET.

[0098] In the present invention, the conductive path is used to connect various electronic components in the external main circuit, and by transmitting current between the electronic components, the electronic components in the external main circuit can work together. The conductive path includes conductive elements and conductive materials in the external main circuit. Specifically, the conductive path includes one of a conductive copper column, a conductive copper sheet, and a wire.

[0099] In the resonator of the present invention, each PCB resonance unit is placed near the conductive path, which specifically means that the magnetic flux lines in the magnetic field generated by the conductive path pass through the PCB resonance unit in a direction perpendicular to the surface of the PCB board in each PCB resonance unit. When the number of PCB resonance units is greater than one, all PCB resonance units are distributed circumferentially around the conductive path. The distribution of the PCB resonance units circumferentially around the conductive path specifically means that the PCB boards in each PCB resonance unit are arranged radially with the current direction in the conductive path as the axial direction. The side of the PCB resonance unit close to the conductive path is axially spaced from the current direction in the conductive path ( Figure 1 The direction of i(t) in the figure is parallel to the PCB resonant unit and the distance between the PCB resonant unit and the conductive path is determined by Figure 1 The letter "d" in the figure is usually smaller than the overall width of the spiral inductor (indicated by the Figure 1 The letter "a" in stands for half of ).

[0100] In the PCB resonant unit, the spiral inductor is designed based on the principle of electromagnetic induction, which can significantly improve the degree of coupling and thus enhance the transmission of ringing energy to the external loop.

[0101] The structure of the spiral inductor is as follows: the spiral inductor is arranged close to the conductive path of the external loop, that is, the spiral inductor is arranged on the side of the PCB board close to the conductive path to improve the coupling degree. The spiral inductor adopts a double-layer planar spiral inductor structure. The spiral design of the double-layer planar spiral inductor structure can increase the inductance value and reduce the volume of the resonator. The double-layer planar spiral inductor structure is mainly composed of two planar spiral coils. The two planar spiral coils have the same rotation direction, and the current direction in the two planar spiral coils is the same, that is, the current direction in the two planar spiral coils is clockwise or counterclockwise. The magnetic field direction generated by the two planar spiral coils is the same, and the two planar spiral coils are coaxial.

[0102] Two planar spiral coils are arranged on the two side surfaces of the PCB board respectively. Each planar spiral coil is wound along a rectangular spiral path on the corresponding PCB board surface according to the preset number of turns and spacing. Each corner of the rectangular spiral path adopts a rounded transition to reduce magnetic leakage, thereby improving the coupling degree between the spiral inductor and the main circuit, and ultimately improving the energy transmission efficiency, so that the ringing energy in the main circuit is more efficiently coupled to each discrete PCB resonant unit. Among them, the rectangular spiral path is a rectangular spiral, and winding along the rectangular spiral path specifically means that the wire is based on the edge of the rectangle and spirally unfolds outward or inward layer by layer.

[0103] The design parameters of the spiral inductor include the number of turns, spacing, width and thickness of the coil. Figure 1 As shown, a is the length of the spiral inductor, b is the width of the spiral inductor, s is the line spacing of the spiral inductor, w is the line width of the spiral inductor, d is the distance between the spiral inductor and the conductive path, is the average distance between each turn of the wire. In a specific implementation, the design parameters of the spiral inductor can be adjusted according to actual needs to optimize the resonance effect, thereby improving the ringing suppression effect.

[0104] The design parameters of the spiral inductor are calculated according to the following formula to obtain the self-inductance L2 of the spiral inductor:

[0105]

[0106] Among them, L2 is the self-inductance of the spiral inductor in the RLC resonant circuit, μ0 is the vacuum permeability, l is the total length of the coil, w is the coil wiring width, r is the coil wiring thickness, n is the number of coil turns, and M is the mutual inductance between the external main circuit and the PCB resonant unit.

[0107] Among them, the mutual inductance M between the external main circuit and the PCB resonant unit is calculated by the following formula:

[0108]

[0109] Where M is the mutual inductance between the external main circuit and the PCB resonant unit, μ0 is the vacuum magnetic permeability, l is the total length of the coil, is the average distance between each turn of wire.

[0110] Based on the spiral inductor, according to the principle of PT symmetry, the matching capacitor C2 and resistance R2 of the PCB resonant unit can be further determined. Ignoring minor and high-order effects, for the system composed of the double pulse test overall circuit and each resonant unit, the system coupling model can be expressed as:

[0111]

[0112] Where a1 and a2 represent the resonant modes of the capacitor and inductor resonators in the coupled mode theory, respectively, and their amplitudes can be expressed as A1 and A2, respectively. H is a non-Hermitian-Hamiltonian operator, j is an imaginary unit, ω0 is the natural angular frequency of the system, γ1 is the damping rate of the main circuit, κ is the coupling rate between the main circuit and the resonant unit, and γ2 is the damping rate of the resonant unit.

[0113] In order to analyze the PT symmetry of the system, a regular transformation is performed to change the system reference point. Definition Then we get:

[0114]

[0115] Where H′ is the new Hamiltonian.

[0116] Among them, the new Hamiltonian H'[H',PT] = 0. In order to achieve the best ringing suppression effect, when the analysis system is at the PT symmetric singular point, the matching capacitor C2 and the resistance R2 of the PCB resonant unit correspond as follows:

[0117] The matching capacitance C2 of the capacitor is calculated by the following formula:

[0118]

[0119] Wherein, C2 is the matching capacitance of the capacitor in the RLC resonant circuit, f1 is the ringing frequency of the external main circuit to which the conductive path belongs, and L2 is the self-inductance of the spiral inductor in the RLC resonant circuit;

[0120] Among them, the ringing frequency f1 of the external main circuit to which the conductive path belongs is obtained by the following formula:

[0121]

[0122] Where, L1 is the sum of the stray inductance of the external main circuit and the total parasitic inductance of the power circuit; C ossis the output capacitance of the SiC MOSFET in the external main circuit.

[0123] The resistance value R2 of the resistor is calculated by the following formula:

[0124] R2=2L2(ω0k+γ1)

[0125] Among them, R2 is the resistance of the resistor in the RLC resonant circuit, L2 is the self-inductance of the spiral inductor in the RLC resonant circuit, k is the coupling coefficient between the PCB resonant unit and the external main circuit, γ1 is the damping rate of the external main circuit to which the conductive path belongs, and ω0 is the natural angular frequency of the system.

[0126] The present invention also provides a method for manufacturing the above resonator. The manufacturing method comprises the following steps:

[0127] 1) According to the preset size parameters of the spiral inductor in the RLC resonant circuit, the self-inductance L2 of the spiral inductor is calculated;

[0128] In step 1), the preset size parameters of the spiral inductor are obtained according to the space capacity of the conductive path in the external main circuit; the spiral inductor adopts a double-layer planar spiral inductor structure, the double-layer planar spiral inductor structure is mainly composed of two planar spiral coils, and the size parameters of the spiral inductor include one or more of the number of turns n, the spacing s, the width a and the thickness of the planar spiral coil;

[0129] The self-inductance L2 of the spiral inductor is calculated by the following formula:

[0130]

[0131] Among them, L2 is the self-inductance of the spiral inductor in the RLC resonant circuit, μ0 is the vacuum permeability, l is the total length of the coil, w is the coil wiring width, r is the coil wiring thickness, n is the number of coil turns, and M is the mutual inductance between the external main circuit and the PCB resonant unit.

[0132] 2) According to the self-inductance L2 of the spiral inductor in the RLC resonant circuit, the matching capacitance C2 of the capacitor and the resistance R2 of the resistor are calculated;

[0133] The matching capacitance C2 of the capacitor is calculated by the following formula:

[0134]

[0135] Wherein, C2 is the matching capacitance of the capacitor in the RLC resonant circuit, f1 is the ringing frequency of the external main circuit to which the conductive path belongs, and L2 is the self-inductance of the spiral inductor in the RLC resonant circuit;

[0136] The resistance value R2 of the resistor is calculated by the following formula:

[0137] R2=2L2(ω0k+γ1)

[0138] Among them, R2 is the resistance of the resistor in the RLC resonant circuit, L2 is the self-inductance of the spiral inductor in the RLC resonant circuit, k is the coupling coefficient between the PCB resonant unit and the external main circuit, γ1 is the damping rate of the external main circuit to which the conductive path belongs, and ω0 is the natural angular frequency of the system.

[0139] 3) Determine the model of the capacitor and the model of the resistor according to the matching capacitance C2 of the capacitor and the resistance value R2 of the resistor, and obtain the capacitor and the resistor;

[0140] 4) According to the preset size parameters of the spiral inductor in the RLC resonant circuit, wiring is performed on a double-layer PCB board to obtain a spiral inductor, and the spiral inductor is connected in series with the capacitor and resistor obtained in step 3) to obtain a modular SiC MOSFET ringing suppression resonator.

[0141] The specific embodiments of the present invention are as follows:

[0142] In this embodiment, the resonator is used in a half-bridge SiC power module and is arranged around the terminals to which the bus capacitor is connected.

[0143] Figure 3 Schematic diagram of the coupling between the resonator and the main circuit in the embodiment of the present invention. C2 is the capacitor of the resonator, R2 is the resistor of the resonator, L2 is the spiral inductor of the resonator, and M is the mutual inductance between the main circuit and the PCB resonant unit in the resonator. D1 , L D2 They are the drain parasitic inductance of SiC MOSFET 1 and SiC MOSFET 2, L G1 , L G2 They are the gate parasitic inductance of SiCMOSFET 1 and SiCMOSFET 2, L S1 , L S2 are the source parasitic inductance of SiC MOSFET 1 and SiC MOSFET 2, respectively. GD1 , C GD2 are the gate-drain parasitic capacitance of SiC MOSFET 1 and SiC MOSFET 2, C GS1 , C GS2 are the gate-source parasitic capacitance of SiC MOSFET 1 and SiC MOSFET 2, C DS1 , C DS2are the drain-source parasitic capacitance of SiC MOSFET 1 and SiC MOSFET 2, R esr is the parasitic resistance of busbar capacitance, L loop is the parasitic inductance of the power circuit, L load is the load inductance, C bus is the bus capacitance, V DC is the DC bus voltage.

[0144] Figure 4 Schematic diagram of the topology of the PCB resonant unit and the main circuit in the embodiment of the present invention, wherein L1 is the equivalent inductance of the main circuit, C1 is the equivalent capacitance of the main circuit, and R1 is the equivalent resistance of the main circuit.

[0145] In the SiC power module of this embodiment, the load inductance L load is 125μH, bus capacitance C bus is 320μF, bus voltage V DC The total parasitic inductance L1 of the external main circuit is 111.5nH, the ringing frequency f1 is 14.031MHz, and the damping rate γ1 is 1.93×10 6 .

[0146] In the resonator of this embodiment, the number of PCB resonant units is 11, and the size parameters of the spiral inductor in the RLC resonant circuit are: 1cm×1cm. The self-inductance L2 of the spiral inductor is calculated to be 0.92uH, and the matching capacitance C2 of the capacitor and the resistance R2 of the resistor are 130pF and 27Ω respectively.

[0147] In the resonator of this embodiment, each resonant unit is wired using a double-layer circuit board. For the spiral inductor, the right angles are designed to be rounded at the corners to reduce magnetic leakage and improve coupling capability, and the two layers are wired in the same direction to ensure that the current flows in the same direction.

[0148] In this embodiment, the coupling coefficient k between each PCB resonant unit and the external main circuit is 0.142.

[0149] In order to compare the effect of the present invention on suppressing the ringing phenomenon, the ringing conditions before and after the resonator is added to the SiC power module are compared through a double pulse test. The process of the double pulse test is specifically as follows: the double pulse test circuit is built in the form of a half-bridge, the device under test (SiC MOSFET) is used as the lower tube, and the upper tube remains in the off state. The test circuit also includes load inductance, DC power supply, pulse signal source, and measuring equipment. Before the first pulse is applied, the SiC MOSFET is in the off state. When the gate-source voltage reaches the threshold voltage, the MOSFET begins to turn on, and then the MOSFET remains in the on state until the first pulse signal ends and the MOSFET enters the off state. At the moment of shutdown, severe ringing occurs due to the resonance of parasitic inductance and capacitance. Through the principle of electromagnetic induction, the ringing energy is transmitted through the parasitic inductance in the double pulse test circuit, and the inductor coil in the resonant unit receives the induced electromotive force, which is consumed by the damping element R2. Continue to apply the second pulse, the MOSFET enters the on state, and at the moment of on, severe ringing occurs due to the resonance of parasitic inductance and capacitance. Through the principle of electromagnetic induction, the ringing energy is transmitted through the parasitic inductance in the double pulse test circuit, and the inductor coil in the resonant unit receives it to generate an induced electromotive force, which is consumed by the damping element R2.

[0150] The experimental results are shown in Figure 5 ,Depend on Figure 5 As can be seen from (a), without the ringing suppression resonator, V DS The oscillation duration is 2.6768μs, I D The oscillation duration is 2.4568μs. Figure 5 (b) shows that after adding the ringing suppression resonator, V DS The oscillation duration is 0.7376μs, I D The ringing duration is 0.5676μs, which is reduced by 1.94μs and 1.90μs respectively, that is, suppressed to 27.5% and 23.1%.

[0151] In addition, in this embodiment, V DS and I D The integration is performed to analyze the effect of the resonator on the switching loss of SiC MOSFET. The specific calculation process is carried out in MATLAB. The experimental results are shown in the following table:

[0152]

[0153] It can be seen that, ignoring the measurement error, the change in turn-on loss caused by adding the resonator is about 2%, and the change in turn-off loss is about 1%. Adding the ringing suppression resonator has almost no effect on the switching loss.

[0154] In addition, through V DSThe waveform compares the switching speed changes before and after adding the resonant unit, such as Figure 6 shown. Figure 6 (a) and (b) show that the ringing phenomenon is significantly suppressed before and after adding different numbers of resonant units, but V DS The rising and falling parts overlap, which shows that the resonator of the present invention does not affect the switching speed of SiC MOSFET.

[0155] The above experimental data show that the present invention provides a coil with a high coupling coefficient as a coupled inductor structure, and is composed of a plurality of PCB resonant units, which can be fully coupled with the main circuit in a limited space, and can better play the role of ringing suppression. The present invention cuts off the electrical connection with the main circuit from the root through a discrete structural design, thereby increasing the safety of use. The coupling-enhanced modular SiC MOSFET ringing suppression resonator provided by the present invention can not only significantly improve the coupling coefficient of the resonator, but also flexibly control the number of PCB resonant units according to actual needs. It has the advantages of simple structure, easy integration, low power consumption and high efficiency, etc. It can effectively solve the problem of insufficient suppression of ringing phenomenon in the prior art, and has broad application prospects and market value.

[0156] The above description is only a specific embodiment of the present invention, and these embodiments are only examples of the principles and applications of the present invention. Therefore, many modifications can be made to the exemplary embodiments without departing from the spirit and scope of the present invention defined by the attached claims.

Claims

1. A modular SiC MOSFET ringing suppression resonator with enhanced coupling, characterized in that: The resonator is arranged outside the conductive path in the external main circuit, and the resonator includes at least one PCB resonance unit, and each PCB resonance unit is arranged at the PT symmetric singular point of the external conductive path; the PCB resonance unit includes a PCB board and an RLC resonance circuit arranged on the PCB board, and the RLC resonance circuit is mainly composed of a spiral inductor, a capacitor and a resistor connected in series.

2. The coupled-enhanced modular SiC MOSFET ringing suppression resonator according to claim 1, characterized in that: The resonant frequency of the RLC resonant circuit in each PCB resonant unit is equal to the resonant frequency of the external main circuit; each PCB resonant unit and the external main circuit satisfy the following relationship: γ2-γ1=2κ In the formula, γ1 is the damping rate of the external main circuit, γ2 is the damping rate of the PCB resonance unit, and k is the coupling rate between the PCB resonance unit and the external main circuit.

3. The coupled-enhanced modular SiC MOSFET ringing suppression resonator according to claim 2, characterized in that: In the RLC resonant circuit of each PCB resonant unit, the resistance value R2 of the resistor and the self-inductance L2 of the spiral inductor coil satisfy the following relationship: R2=2L2(ω0k+γ1) Where R2 is the resistance of the resistor in the RLC resonant circuit, L2 is the self-inductance of the spiral inductor in the RLC resonant circuit, k is the coupling coefficient between the PCB resonant unit and the external main circuit, and γ1 is the damping rate of the external main circuit.

4. The coupled-enhanced modular SiC MOSFET ringing suppression resonator according to claim 1, characterized in that: In the RLC resonant circuit of each PCB resonant unit, the matching capacitance C2 of the capacitor and the self-inductance L2 of the spiral inductor coil satisfy the following relationship: Where C2 is the matching capacitance of the capacitor in the RLC resonant circuit, f1 is the ringing frequency of the SiC MOSFET in the external main circuit, and L2 is the self-inductance of the spiral inductor in the RLC resonant circuit.

5. The coupled-enhanced modular SiC MOSFET ringing suppression resonator according to claim 1, characterized in that: The magnetic flux lines in the magnetic field generated by the conductive path pass through the PCB resonant unit in a direction perpendicular to the surface of each PCB resonant unit; All PCB resonant units are spaced and distributed around the conductive path.

6. The coupled-enhanced modular SiC MOSFET ringing suppression resonator according to claim 5, characterized in that: The spiral inductor is provided on one side of the PCB board close to the conductive path. The spiral inductor adopts a double-layer planar spiral inductor structure. The double-layer planar spiral inductor structure is mainly composed of two layers of upper and lower planar spiral coils. The two layers of planar spiral coils have the same rotation direction, and the current directions in the two layers of planar spiral coils are the same.

7. The coupled-enhanced modular SiC MOSFET ringing suppression resonator according to claim 6, characterized in that: Each planar spiral coil is formed by winding a wire along a rectangular spiral path, and each corner of the rectangular spiral path is rounded.

8. A method for manufacturing a modular SiC MOSFET ringing suppression resonator according to any one of claims 1 to 7, characterized in that: The manufacturing method comprises the following steps: 1) According to the preset size parameters of the spiral inductor in the RLC resonant circuit, the self-inductance L2 of the spiral inductor is calculated; 2) According to the self-inductance L2 of the spiral inductor in the RLC resonant circuit, the matching capacitance C2 of the capacitor and the resistance R2 of the resistor are calculated; The matching capacitance C2 of the capacitor is calculated by the following formula: In the formula, C2 is the matching capacitance of the capacitor in the RLC resonant circuit, f1 is the ringing frequency of the external main circuit, and L2 is the self-inductance of the spiral inductor in the RLC resonant circuit; The resistance value R2 of the resistor is calculated by the following formula: R2=2L2(ω0k+γ1) In the formula, R2 is the resistance of the resistor in the RLC resonant circuit, L2 is the self-inductance of the spiral inductor in the RLC resonant circuit, k is the coupling coefficient between the PCB resonant unit and the external main circuit, γ1 is the damping rate of the external main circuit, and ω0 is the natural angular frequency of the system; 3) Determine the model of the capacitor and the model of the resistor according to the matching capacitance C2 of the capacitor and the resistance value R2 of the resistor, and obtain the capacitor and the resistor; 4) According to the preset size parameters of the spiral inductor in the RLC resonant circuit, wiring is performed on a double-layer PCB board to obtain a spiral inductor, and the spiral inductor is connected in series with the capacitor and resistor obtained in step 3) to obtain a PCB resonant unit, and at least one PCB resonant unit is arranged outside the conductive path of the external main circuit, and all PCB resonant units constitute the resonator.

9. The manufacturing method according to claim 8, characterized in that: The preset size parameters of the spiral inductor are obtained according to the space capacity of the conductive path in the external main circuit; the spiral inductor adopts a double-layer planar spiral inductor structure, which is mainly composed of two planar spiral coils. The size parameters of the spiral inductor include one or more of the number of turns, spacing, width and thickness of the planar spiral coil; the self-inductance L2 of the spiral inductor is calculated by the following formula: Where L2 is the self-inductance of the spiral inductor in the RLC resonant circuit, μ0 is the vacuum permeability, l is the total length of the coil, w is the coil wiring width, r is the coil wiring thickness, n is the number of coil turns, and M is the mutual inductance between the external main circuit and the PCB resonant unit.

10. An energy conversion system using the modular SiC MOSFET ringing suppression resonator according to any one of claims 1 to 7, characterized in that: The energy conversion system includes one or more of a power converter, an inverter and a drive circuit.

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