A parallel switch pulse generator based on magnetic induction current sharing

Abstract

A parallel switch pulse generator based on magnetic induction current sharing, comprising: a control signal generation module, an optoelectronic isolation driving module, a solid state switch driving module, a magnetic induction current sharing module, a capacitor energy storage pulse output module and a load. The application realizes the output of larger pulse current and power of the capacitor energy storage type pulse generator more simply and efficiently through switch parallel connection, and the circuit topology structure is simple, the parameters are flexible and adjustable, and the modules can be stacked. The magnetic induction current sharing technology adopted by the application solves the problem of uneven current between parallel switch devices, and ensures the reliability and stability of the large current output of the parallel switch pulse generator. The pulse output voltage and current amplitude, pulse width and pulse frequency of the parallel switch pulse generation technology based on magnetic induction current sharing proposed by the application are flexible and adjustable.

Description

Technical Field

[0001] This invention relates to the field of pulse power source technology, specifically to a pulse generator based on magnetic induction current sharing parallel switching. Background Technology

[0002] In recent years, pulsed power technology has been widely used in food processing, microalgae treatment, plasma reactions, and underwater discharge. In these applications, due to their low-impedance load characteristics, in addition to the need for high-voltage pulse output, the ability to generate large currents is also required. Pulse generators are also developing towards higher power. Simultaneously, to meet the demands of large-scale industrial applications requiring low cost, short pulse width, and high repetition rate, higher requirements are placed on pulse sources and their switching devices. Existing pulse generators based on capacitor energy storage can achieve high-voltage output, but their output current is limited by the switching devices used. Currently, the rated current of a single commercially available switch is still very limited, and increasing the rated output current of pulse generators remains a challenge that needs to be addressed.

[0003] Parallel connection of switches is a simpler and more efficient solution to improve the output current and power of a pulse generator. However, due to the dispersion of parameters between devices and the lack of consistency in circuit parasitic parameters, current imbalance inevitably occurs in different parallel switch branches when two or more switches are connected in parallel. This includes imbalance in static current after conduction and imbalance in transient current generated during the switching process. Ensuring current sharing in parallel switches is a prerequisite for the long-term stable operation of the generator and remains an unresolved challenge.

[0004] Existing parallel module schemes can output high-current pulses on low-impedance loads. However, these schemes increase the size and structural complexity of the pulse generator. Furthermore, the lack of current sharing measures among the parallel modules results in current imbalances that pose a significant challenge to the long-term reliable and stable operation of the entire pulse generator. Summary of the Invention

[0005] The purpose of this invention is to provide a magnetic induction current sharing parallel switch pulse generator, comprising: a control signal generation module, an opto-isolation drive module, a solid-state switch drive module, a magnetic induction current sharing module, a capacitor energy storage pulse output module, and a load.

[0006] The control signal generation module is used to generate solid-state switch control signals.

[0007] The opto-isolation drive module is used to eliminate the high-potential floating of solid-state switches.

[0008] After receiving the solid-state switch control signal, the solid-state switch driver module controls the on and off of each solid-state switch in the capacitor energy storage pulse output module, as well as the on and off time.

[0009] The magnetic induction current sharing module is used to eliminate uneven current between solid-state switches.

[0010] The capacitor energy storage pulse output module is used to generate pulse signals and input the pulse signals into the load.

[0011] The circuit topology based on the magnetic induction current sharing parallel switching pulse generator is shown below:

[0012] The first and second transmission lines are symmetrically wound around both sides of the magnetic ring.

[0013] Three capacitors and one solid-state switch are used as the first current branch and the second current branch.

[0014] Let one end of the first transmission line be A, and the other end be B. Let one end of the second transmission line be C, and the other end be D. Power supply V. dc The positive terminal is E, the negative terminal is F, and the F terminal is grounded.

[0015] The capacitor C is connected to terminal E. dc Then connect to the F terminal.

[0016] Terminal A and Terminal C are connected, and Terminal E is also connected.

[0017] Terminal B is connected in sequence to the first current branch and resistor R. g1 Resistance R L Grounded afterward.

[0018] Terminal B is connected in sequence to the first current branch and resistor R. L Grounded afterward.

[0019] Terminal D is connected in sequence to the second current branch and resistor R. L Grounded afterward.

[0020] Terminal D is connected in sequence to the second current branch and resistor R. g2 Resistance R g1 Resistance R L Grounded afterward.

[0021] Furthermore, the circuit topologies of the first current branch and the second current branch are shown below:

[0022] Terminal B is connected to the drain of solid-state switch S1, and the source of solid-state switch S1 is connected to resistor R. L Grounded afterward.

[0023] The D terminal is connected to the drain of the solid-state switch S2, and the source of the solid-state switch S2 is connected to the resistor R. L Grounded afterward.

[0024] The drain connection capacitor C of the solid-state switch S1 ds1It is then connected to the source of solid-state switch S1.

[0025] The drain connection capacitor C of the solid-state switch S1 gd1 It is then connected to the gate of solid-state switch S1.

[0026] The gate connection capacitor C of the solid-state switch S1 gs 1 is then connected to the source of solid-state switch S1.

[0027] The drain connection capacitor C of the solid-state switch S2 ds2 It is then connected to the source of solid-state switch S2.

[0028] The drain connection capacitor C of the solid-state switch S2 gd2 It is then connected to the gate of solid-state switch S2.

[0029] The gate connection capacitor C of the solid-state switch S2 gs2 It is then connected to the source of solid-state switch S2.

[0030] The gate of the solid-state switch S1 is connected in sequence to a resistor R. g1 Resistance R L Grounded afterward.

[0031] The gate connection resistor R of the solid-state switch S1 g2 It is then connected to the gate of solid-state switch S2.

[0032] Furthermore, both solid-state switches S1 and S2 are MOSFET switches.

[0033] Furthermore, the pulse generator also includes a host computer.

[0034] The host computer generates circuit parameters and transmits them to the control signal generation module, which then generates solid-state switch control signals.

[0035] Furthermore, when solid-state switches S1 and S2 are turned on, the first current branch and the second current branch flow into two coupled coils with the same number of turns on the magnetic core, generating magnetic fluxes in opposite directions in the magnetic circuit.

[0036] Furthermore, the current difference between the first and second current branches generates magnetic flux in the magnetic core, inducing an electromotive force V in the primary coil. m The secondary coil induces an electromotive force -V m The electromotive force drives the unbalanced current to remain zero, and the electromotive force V m As shown below:

[0037] V m =L m dΔi d / dt (1)

[0038] In the formula, L m The magnetizing inductance of the magnetically coupled coil is Δi. d t represents the current difference within the coil.

[0039] Furthermore, the magnetizing inductance L of the coupling coil m and leakage L σ As shown below:

[0040]

[0041] In the formula, n1 is the number of turns of the coil. D max D min These are the outer and inner diameters of the magnetic core, respectively. Δi d This represents the current difference within the coil. μ r Let be the relative permeability of the magnetic core. μ0 is the permeability of free space. d ν is the current flowing through the coil. l is the length of the coil.

[0042] Among them, the magnetic flux density B in the magnetic core c As shown below:

[0043]

[0044] In the formula, μ is the magnetic permeability. m Let be the magnetic field strength in the magnetic core. d1 Let i be the current within the first transmission line. d2 This refers to the current within the second transmission line.

[0045] Leakage flux density B in air a As shown below:

[0046] B a =μ0H σ =n1μ0i d / l (4)

[0047] In the formula, H σ The magnetic field strength in the air.

[0048] The cross-sectional area S of the magnetic core is shown below:

[0049] S = 0.5(D max -D min )h (5)

[0050] In the formula, h is the height of the magnetic core.

[0051] Furthermore, during the transient process of the solid-state switches S1 and S2 being turned on, the dynamic response time τ1 of the unbalanced current is as follows:

[0052] τ1=(2L m +L σ +L d1 +L s1 ) / R ds1≈ 2L m / R ds (6)

[0053] In the formula, L m L is the magnetizing inductance of the magnetically coupled coil. σ For the leakage inductance of the magnetically coupled coil, L d1 For solid-state switch S i-1 The drain parasitic inductance, L s1 For solid-state switch S i-1 The source parasitic inductance, R ds1 For solid-state switch S i-1 The resistance between the drain and source, R ds This is the variable resistor during the dynamic switching process.

[0054] Furthermore, after the solid-state switches S1 and S2 are fully turned on, the magnetizing inductor L... m For unbalanced current Δi d The time constant τ2 that produces the inhibitory effect is shown below:

[0055] τ2=2L m / R dson1 (7)

[0056] In the formula, R dson1 is the on-resistance of solid-state switch S1.

[0057] Furthermore, the pulse output voltage and current amplitude, pulse width, and pulse frequency of the pulse generator are all adjustable.

[0058] The technical effects of this invention are undeniable. This invention proposes a parallel switching pulse generation technology based on Magnetic Induction Current Balance (MICB). By employing MICB technology, only one coupling coil is used to effectively suppress the transient and static unbalanced currents that occur during pulse generation, solving the problem of uneven current distribution between parallel switching devices, achieving a larger pulse current output from the pulse generator, while ensuring the reliability and stability of the pulse generator's large current output.

[0059] The beneficial effects of this invention include:

[0060] 1. By using parallel switching, a larger pulse current and power output of the capacitor energy storage pulse generator is achieved more simply and efficiently. The circuit topology is simple, the parameters are flexibly adjustable, and multiple modules can be stacked.

[0061] 2. The magnetic induction current sharing technology adopted solves the problem of uneven current between parallel switching devices, ensuring the reliability and stability of the high current output of the pulse generator of the parallel switch.

[0062] 3. The pulse output voltage and current amplitude, pulse width, and pulse frequency proposed in this invention based on magnetic induction current sharing parallel switch pulse generation technology are all flexibly adjustable. Attached Figure Description

[0063] Figure 1 This is a schematic diagram showing the composition of each module of the present invention;

[0064] Figure 2 This is a schematic diagram of the topology of a magnetic induction current sharing parallel switch module.

[0065] Figure 3 This is a schematic diagram of the physical model of a magnetic induction coupling coil; Figure 3 (a) is a schematic diagram of the front of the coil. Figure 3 (b) is a schematic diagram of the coil cross-section;

[0066] Figure 4 This is a schematic diagram of the equivalent circuit model for magnetic induction current sharing during the switching dynamic process;

[0067] Figure 5 A schematic diagram of the equivalent circuit model of magnetic induction current sharing after the switch is fully turned on;

[0068] Figure 6 This is a schematic diagram of a magnetic induction current sharing simulation circuit.

[0069] Figure 7 A schematic diagram of the simulated switching current of different branches of a parallel SiC MOSFET; Figure 7 (a) is a schematic diagram without flow equalization measures. Figure 7 (b) is a schematic diagram of magnetically induced current sharing;

[0070] Figure 8 This is a schematic diagram of the experimental testing platform;

[0071] Figure 9 A schematic diagram of the experimental waveforms of the switching current in different branches of a parallel SiC MOSFET; Figure 9 (a) is a schematic diagram without flow equalization measures. Figure 9 (b) is a schematic diagram of magnetic induction current sharing. Detailed Implementation

[0072] The present invention will be further described below with reference to embodiments, but it should not be construed that the scope of the present invention is limited to the following embodiments. Various substitutions and modifications made based on ordinary technical knowledge and common practices in the art without departing from the above-described technical concept of the present invention should be included within the scope of protection of the present invention.

[0073] Example 1:

[0074] See Figures 1 to 9 A magnetic induction current sharing parallel switch pulse generator includes: a control signal generation module, an opto-isolation drive module, a solid-state switch drive module, a magnetic induction current sharing module, a capacitor energy storage pulse output module, and a load.

[0075] The control signal generation module is used to generate solid-state switch control signals.

[0076] The opto-isolation drive module is used to eliminate the high-potential floating of solid-state switches.

[0077] After receiving the solid-state switch control signal, the solid-state switch driver module controls the on and off of each solid-state switch in the capacitor energy storage pulse output module, as well as the on and off time.

[0078] The magnetic induction current sharing module is used to eliminate uneven current between solid-state switches.

[0079] The capacitor energy storage pulse output module is used to generate pulse signals and input the pulse signals into the load.

[0080] The circuit topology based on the magnetic induction current sharing parallel switching pulse generator is shown below:

[0081] The first and second transmission lines are symmetrically wound around both sides of the magnetic ring.

[0082] Three capacitors and one solid-state switch are used as the first current branch and the second current branch.

[0083] Let one end of the first transmission line be A, and the other end be B. Let one end of the second transmission line be C, and the other end be D. Power supply V. dc The positive terminal is E, the negative terminal is F, and the F terminal is grounded.

[0084] The capacitor C is connected to terminal E. dc Then connect to the F terminal.

[0085] Terminal A and Terminal C are connected, and Terminal E is also connected.

[0086] Terminal B is connected in sequence to the first current branch and resistor R. g1 Resistance R L Grounded afterward.

[0087] Terminal B is connected in sequence to the first current branch and resistor R. L Grounded afterward.

[0088] Terminal D is connected in sequence to the second current branch and resistor R. L Grounded afterward.

[0089] Terminal D is connected in sequence to the second current branch and resistor R. g2 Resistance R g1 Resistance R L Grounded afterward.

[0090] Example 2:

[0091] A magnetic induction current sharing parallel switch pulse generator is described, the main technical contents of which are given in Embodiment 1. Further, the circuit topology of the first current branch and the second current branch is shown below:

[0092] Terminal B is connected to the drain of solid-state switch S1, and the source of solid-state switch S1 is connected to resistor R. L Grounded afterward.

[0093] The D terminal is connected to the drain of the solid-state switch S2, and the source of the solid-state switch S2 is connected to the resistor R. L Grounded afterward.

[0094] The drain connection capacitor C of the solid-state switch S1 ds1 It is then connected to the source of solid-state switch S1.

[0095] The drain connection capacitor C of the solid-state switch S1 gd1 It is then connected to the gate of solid-state switch S1.

[0096] The gate connection capacitor C of the solid-state switch S1 gs1 It is then connected to the source of solid-state switch S1.

[0097] The drain connection capacitor C of the solid-state switch S2 ds2 It is then connected to the source of solid-state switch S2.

[0098] The drain connection capacitor C of the solid-state switch S2 gd2 It is then connected to the gate of solid-state switch S2.

[0099] The gate connection capacitor C of the solid-state switch S2 gs2 It is then connected to the source of solid-state switch S2.

[0100] The gate of the solid-state switch S1 is connected in sequence to a resistor R. g1 Resistance R L Grounded afterward.

[0101] The gate connection resistor R of the solid-state switch S1 g2It is then connected to the gate of solid-state switch S2.

[0102] Example 3:

[0103] A magnetic induction current sharing parallel switch pulse generator is provided. The main technical contents are described in any one of Embodiments 1 to 2. Furthermore, both the solid-state switch S1 and the solid-state switch S2 are MOSFET switches.

[0104] Example 4:

[0105] A magnetic induction current sharing parallel switch pulse generator is provided. The main technical contents are described in any one of embodiments 1 to 3. Furthermore, the pulse generator also includes a host computer.

[0106] The host computer generates circuit parameters and transmits them to the control signal generation module, which then generates solid-state switch control signals.

[0107] Example 5:

[0108] A magnetic induction current sharing parallel switch pulse generator is provided. The main technical contents are described in any one of embodiments 1 to 4. Furthermore, when solid-state switches S1 and S2 start to conduct, the first current branch and the second current branch flow into two coupled coils with the same number of turns on the magnetic core, generating magnetic fluxes in opposite directions in the magnetic circuit.

[0109] Example 6:

[0110] A magnetic induction current-sharing parallel switching pulse generator is described, with the main technical details provided in any one of embodiments 1 to 5. Further, the current difference between the first and second current branches generates magnetic flux in the magnetic core, inducing an electromotive force V in the primary coil. m The secondary coil induces an electromotive force -V m The electromotive force drives the unbalanced current to remain zero, and the electromotive force V m As shown below:

[0111] V m =L m dΔi d / dt (1)

[0112] In the formula, L m The magnetizing inductance of the magnetically coupled coil is Δi. d t represents the current difference within the coil.

[0113] Example 7:

[0114] A magnetic induction current-sharing parallel switching pulse generator, the main technical contents of which are described in any one of embodiments 1 to 6, further wherein the magnetizing inductance L of the coupling coil is... m and leakage L σAs shown below:

[0115]

[0116] In the formula, n1 is the number of turns of the coil. D max D min These are the outer and inner diameters of the magnetic core, respectively. Δi d This represents the current difference within the coil. μ r Let be the relative permeability of the magnetic core. μ0 is the permeability of free space. d ν is the current flowing through the coil. l is the length of the coil.

[0117] Among them, the magnetic flux density B in the magnetic core c As shown below:

[0118]

[0119] In the formula, μ is the magnetic permeability. m Let be the magnetic field strength in the magnetic core. d1 Let i be the current within the first transmission line. d2 This refers to the current within the second transmission line.

[0120] Leakage flux density B in air a As shown below:

[0121] B a =μ0H σ =n1μ0i d / l (4)

[0122] In the formula, H σ The magnetic field strength in the air.

[0123] The cross-sectional area S of the magnetic core is shown below:

[0124] S = 0.5(D max -D min )h (5)

[0125] In the formula, h is the height of the magnetic core.

[0126] Example 8:

[0127] A magnetic induction current-sharing parallel switch pulse generator, the main technical contents of which are described in any one of embodiments 1 to 7, further, the dynamic response time τ1 of the unbalanced current during the transient process of the solid-state switches S1 and S2 being turned on is as follows:

[0128] τ1=(2L m +L σ +L d1 +L s1 ) / R ds1 ≈2Lm / R ds (6)

[0129] In the formula, L m L is the magnetizing inductance of the magnetically coupled coil. σ For the leakage inductance of the magnetically coupled coil, L d1 For solid-state switch S i-1 The drain parasitic inductance, L s1 For solid-state switch S i-1 The source parasitic inductance, R ds1 For solid-state switch S i-1 The resistance between the drain and source, R ds This is the variable resistor during the dynamic switching process.

[0130] Example 9:

[0131] A magnetic induction current-sharing parallel switch pulse generator, the main technical contents of which are described in any one of embodiments 1 to 8, further wherein after the solid-state switches S1 and S2 are fully turned on, the magnetizing inductor L m For unbalanced current Δi d The time constant τ2 that produces the inhibitory effect is shown below:

[0132] τ2=2L m / R dson1 (7)

[0133] In the formula, R dson1 is the on-resistance of solid-state switch S1.

[0134] Example 10:

[0135] A magnetic induction current sharing parallel switch pulse generator is provided. The main technical contents are described in any one of embodiments 1 to 9. Furthermore, the pulse output voltage and current amplitude, pulse width, and pulse frequency of the pulse generator are all adjustable.

[0136] Example 11:

[0137] See Figures 1 to 9 A magnetic induction current sharing parallel switch pulse generator includes: a control signal generation module, an opto-isolation drive module, a solid-state switch drive module, a magnetic induction current sharing module, a capacitor energy storage pulse output module, and a load.

[0138] The control signal generation module is used to generate solid-state switch control signals.

[0139] The opto-isolation drive module is used to eliminate the high-potential floating of solid-state switches.

[0140] After receiving the solid-state switch control signal, the solid-state switch driver module controls the on and off of each solid-state switch in the capacitor energy storage pulse output module, as well as the on and off time.

[0141] The magnetic induction current sharing module is used to eliminate uneven current between solid-state switches.

[0142] The capacitor energy storage pulse output module is used to generate pulse signals and input the pulse signals into the load.

[0143] The circuit topology based on the magnetic induction current sharing parallel switching pulse generator is shown below:

[0144] The first and second transmission lines are symmetrically wound around both sides of the magnetic ring.

[0145] Three capacitors and one solid-state switch are used as the first current branch and the second current branch.

[0146] Let one end of the first transmission line be A, and the other end be B. Let one end of the second transmission line be C, and the other end be D. Power supply V. dc The positive terminal is E, the negative terminal is F, and the F terminal is grounded.

[0147] The capacitor C is connected to terminal E. dc Then connect to the F terminal.

[0148] Terminal A and Terminal C are connected, and Terminal E is also connected.

[0149] Terminal B is connected in sequence to the first current branch and resistor R. g1 Resistance R L Grounded afterward.

[0150] Terminal B is connected in sequence to the first current branch and resistor R. L Grounded afterward.

[0151] Terminal D is connected in sequence to the second current branch and resistor R. L Grounded afterward.

[0152] Terminal D is connected in sequence to the second current branch and resistor R. g2 Resistance R g1 Resistance R L Grounded afterward.

[0153] The various modules of this invention patent are as follows: Figure 1 As shown.

[0154] Example 12:

[0155] A magnetic induction current sharing parallel switch pulse generator is described in Embodiment 11. Further, the circuit topologies of the first current branch and the second current branch are as follows:

[0156] Terminal B is connected to the drain of solid-state switch S1, and the source of solid-state switch S1 is connected to resistor R. L Grounded afterward.

[0157] The D terminal is connected to the drain of the solid-state switch S2, and the source of the solid-state switch S2 is connected to the resistor R. L Grounded afterward.

[0158] The drain connection capacitor C of the solid-state switch S1 ds1 It is then connected to the source of solid-state switch S1.

[0159] The drain connection capacitor C of the solid-state switch S1 gd1 It is then connected to the gate of solid-state switch S1.

[0160] The gate connection capacitor C of the solid-state switch S1 gs1 It is then connected to the source of solid-state switch S1.

[0161] The drain connection capacitor C of the solid-state switch S2 ds2 It is then connected to the source of solid-state switch S2.

[0162] The drain connection capacitor C of the solid-state switch S2 gd2 It is then connected to the gate of solid-state switch S2.

[0163] The gate connection capacitor C of the solid-state switch S2 gs2 It is then connected to the source of solid-state switch S2.

[0164] The gate of the solid-state switch S1 is connected in sequence to a resistor R. g1 Resistance R L Grounded afterward.

[0165] The gate connection resistor R of the solid-state switch S1 g2 It is then connected to the gate of solid-state switch S2.

[0166] Example 13:

[0167] A magnetic induction current sharing parallel switch pulse generator is provided. The main technical contents are described in any one of embodiments 11 to 12. Furthermore, both the solid-state switch S1 and the solid-state switch S2 are MOSFET switches.

[0168] Example 14:

[0169] A magnetic induction current sharing parallel switch pulse generator is provided. The main technical contents are described in any one of embodiments 11 to 13. Furthermore, the pulse generator also includes a host computer.

[0170] The host computer generates circuit parameters and transmits them to the control signal generation module, which then generates solid-state switch control signals.

[0171] Example 15:

[0172] A magnetic induction current sharing parallel switching pulse generator, the main technical contents of which are described in any one of embodiments 11 to 14, further, Figure 2 It is a topology circuit of magnetic induction current sharing parallel switch pulse generation technology. When solid-state switches S1 and S2 start to conduct, the first current branch and the second current branch flow into two coupled coils with the same number of turns on the magnetic core, generating magnetic flux in opposite directions in the magnetic circuit.

[0173] Example 16:

[0174] A parallel switching pulse generator based on magnetic induction current sharing is described in any one of embodiments 11 to 15. Further, assuming completely identical devices and perfectly symmetrical power circuits, the currents in the two parallel branches are equal, generating magnetic fluxes of opposite directions and equal magnitudes in the magnetic core. The resultant magnetic flux is zero and has no effect on the branch currents. However, due to inconsistencies in device parameters and circuit parasitic parameters, the currents in the two branches deviate. The current difference between the first and second current branches generates magnetic flux in the magnetic core. According to Faraday's law of electromagnetic induction, the primary coil will induce an electromotive force V. m The secondary coil induces an electromotive force -V m The electromotive force (EMF) drives the unbalanced current to remain zero, thus achieving current balance in the two switching branches. Essentially, the magnetically coupled coil uses magnetic flux as a medium to transfer current from one branch to another, ideally eliminating unbalanced current without energy loss. EMF V m As shown below:

[0175] V m =L m dΔi d / dt (1)

[0176] In the formula, L m The magnetizing inductance of the magnetically coupled coil is Δi. d t represents the current difference within the coil.

[0177] Example 17:

[0178] A magnetic induction current sharing parallel switching pulse generator, the main technical contents of which are described in any one of embodiments 11 to 16, further, Figure 3 This is the physical model of a magnetically coupled coil, which, according to Ampere's circuital law,

[0179]

[0180] In the formula, n is the number of turns of the coil; i is the coil current; H is the magnetic field strength; and D is the equivalent diameter of the coil. max D min These are the outer and inner diameters of the magnetic core, respectively.

[0181] because

[0182]

[0183] The magnetizing inductance L of the coupling coil m and leakage L σ As shown below:

[0184]

[0185] In the formula, n1 is the number of turns of the coil. D max D min These are the outer and inner diameters of the magnetic core, respectively. Δi d This represents the current difference within the coil. μ r ρ is the relative permeability of the magnetic core. μ0 is the permeability of free space, μ0 = 4π × 10⁻⁶. -7 H / m. i d ν is the current flowing through the coil. l is the length of the coil.

[0186] Among them, the magnetic flux density B in the magnetic core c As shown below:

[0187]

[0188] In the formula, μ is the magnetic permeability. m Let be the magnetic field strength in the magnetic core. d1 Let i be the current within the first transmission line. d2 This refers to the current within the second transmission line.

[0189] Leakage flux density B in air a As shown below:

[0190] B a =μ0H σ =n1μ0i d / l (6)

[0191] In the formula, H σ The magnetic field strength in the air.

[0192] The cross-sectional area S of the magnetic core is shown below:

[0193] S = 0.5(D max -D min )h (7)

[0194] In the formula, h is the height of the magnetic core.

[0195] Example 18:

[0196] A magnetic induction current sharing parallel switching pulse generator, the main technical contents of which are described in any one of embodiments 11 to 17, further, Figure 4 This is the equivalent circuit model of magnetic induction current sharing during the dynamic process of the switch. The SiC MOSFET is equivalent to a controlled source and a variable resistor model, and the branch current satisfies:

[0197]

[0198] Where, L1=L m +L σ1 L2 = L m +L σ2 If L σ1 =L σ2 =L σ i d1 =i d2 +Δi d R ds2 =R ds1 +ΔR ds L d2 =L d1 +ΔL d L s2 =L s1 +ΔL s The equation can be simplified to:

[0199]

[0200] Meanwhile, due to the fast turn-on speed of MOSFETs, di d2 / dt can be approximated as:

[0201]

[0202] Among them, I L For the current across the load resistor after the MOSFET is fully turned on, the equation, after Laplace transformation, yields:

[0203]

[0204] During the transient process of solid-state switches S1 and S2 being turned on, the dynamic response time τ1 of the unbalanced current is as follows:

[0205] τ1=(2L m +L σ +L d1 +L s1 ) / R ds1 ≈2L m / Rds (12)

[0206] In the formula, L m L is the magnetizing inductance of the magnetically coupled coil. σ For the leakage inductance of the magnetically coupled coil, L d1 For solid-state switch S i-1 The drain parasitic inductance, L s1 For solid-state switch S i-1 The source parasitic inductance, R ds1 For solid-state switch S i-1 The resistance between the drain and source, R ds This refers to the variable resistor R during the switching dynamic process. ds Typically, the value is large, in the MΩ range, so the unbalanced current during the switching dynamic process can be effectively suppressed in a very short time.

[0207] Example 19:

[0208] A magnetic induction current sharing parallel switching pulse generator, the main technical contents of which are described in any one of embodiments 11 to 18, further, Figure 5 This is the equivalent circuit model of the magnetic induction current sharing in the switching branch after the switch is fully turned on. At this point, the SiC MOSFET can be equivalent to an on-resistance R. dson The transient unbalanced current of the switch has been effectively suppressed, i d1 =i d2 However, due to the switch on-resistance R dson There are differences. As the pulse width increases, the static unbalanced current in the switching branch gradually increases. At this time, the current sharing principle of the magnetic induction coupling coil is as follows:

[0209] From the branch current equation,

[0210] i d1 +i d2 =I L (13)

[0211] It can be known that:

[0212] 2i d1 -Δi d =I L ,2i d2 +Δi d =I L (14)

[0213] Then we can obtain:

[0214]

[0215] At this time, the branch current satisfies the equation:

[0216]

[0217] If R dson2 =R dson1 +ΔR dson Equation (17) can be simplified to:

[0218]

[0219] because

[0220]

[0221] Equation (19), after the Laplace transformation, can be expressed as:

[0222]

[0223] After the solid-state switches S1 and S2 are fully turned on, the magnetizing inductor L m For unbalanced current Δi d The time constant τ2 that produces the inhibitory effect is shown below:

[0224] τ2=2L m / R dson1 (20)

[0225] In the formula, R dson1 is the on-resistance of solid-state switch S1.

[0226] Example 20:

[0227] A magnetic induction current sharing parallel switch pulse generator is provided. The main technical contents are described in any one of embodiments 11 to 19. Furthermore, the pulse output voltage and current amplitude, pulse width, and pulse frequency of the pulse generator are all adjustable.

[0228] Example 11:

[0229] See Figures 1 to 5 A magnetic induction current sharing parallel switch pulse generator, the main technical contents of which include:

[0230] The various modules of this invention patent are as follows: Figure 1 As shown.

[0231] Figure 2This is a topology circuit using magnetic induction current-sharing parallel switching pulse generation technology. When the parallel SiC MOSFETs begin to conduct, the currents in the two SiC MOSFET branches flow into two coupled coils with the same number of turns on a common magnetic core, generating magnetic fluxes in opposite directions in the magnetic circuit. Assuming the devices are perfectly identical and the power loop is perfectly symmetrical, the currents in the two parallel branches are equal, generating magnetic fluxes in opposite directions and of equal magnitude in the magnetic core. The resultant magnetic flux is zero and has no effect on the branch currents. However, due to inconsistencies in device parameters and circuit parasitic parameters, there is a deviation in the currents of the two branches. This current difference generates magnetic flux in the magnetic core. According to Faraday's law of electromagnetic induction, the primary coil will induce an electromotive force V. m The secondary coil induces an electromotive force -V m V m =L m dΔi d The electromotive force / dt will drive the unbalanced current to remain zero, thus achieving current balance between the two switching branches. Essentially, the magnetically coupled coil uses magnetic flux as a medium to transfer current from one branch to another, ideally eliminating unbalanced current without energy loss.

[0232] Figure 3 This is the physical model of a magnetically coupled coil, which, according to Ampere's circuital law,

[0233]

[0234] In the formula, n is the number of turns of the coil; i is the coil current; H is the magnetic field strength; and D is the equivalent diameter of the coil. max D min These are the outer and inner diameters of the magnetic core, respectively.

[0235] Magnetic flux density B in the magnetic core c and the leakage magnetic flux density B in the air a It can be represented as:

[0236] B a =μ0H σ =nμ0i d / l (2)

[0237]

[0238] In the formula, μ0 is the free permeability μ0 = 4π × 10 -7 H / m, μ r Let l be the relative permeability of the magnetic core and l be the length of the coil.

[0239] because

[0240]

[0241] Where S is the cross-sectional area of ​​the magnetic core, S = 0.5 (D max -D min h, where h is the height of the magnetic core.

[0242] Then the magnetizing inductance L of the magnetically coupled coil can be obtained. m and leakage L σ for:

[0243]

[0244] Figure 4 This is the equivalent circuit model of magnetic induction current sharing during the dynamic process of the switch. The SiC MOSFET is equivalent to a controlled source and a variable resistor model, and the branch current satisfies:

[0245]

[0246] Where, L1=L m +L σ1 L2 = L m +L σ2 If L σ1 =L σ2 =L σ i d1 =i d2 +Δi d R ds2 =R ds1 +ΔR ds L d2 =L d1 +ΔL d L s2 =L s1 +ΔL s The equation can be simplified to:

[0247]

[0248] Meanwhile, due to the fast turn-on speed of MOSFETs, di d2 / dt can be approximated as:

[0249]

[0250] Among them, I L For the current across the load resistor after the MOSFET is fully turned on, the equation, after Laplace transformation, yields:

[0251]

[0252] It can be seen that during the switching transient process, the dynamic response time of the unbalanced current is:

[0253] τ 1＝ (2Lm +L σ +L d1 +L s1 ) / R ds1 ≈2L m / R ds (10)

[0254] During the switching dynamic process, the variable resistor R ds Typically, the value is large, in the MΩ range, so the unbalanced current during the switching dynamic process can be effectively suppressed in a very short time.

[0255] Figure 5 This is the equivalent circuit model of the magnetic induction current sharing in the switching branch after the switch is fully turned on. At this point, the SiC MOSFET can be equivalent to an on-resistance R. dson The transient unbalanced current of the switch has been effectively suppressed, i d1 =i d2 However, due to the switch on-resistance R dson There are differences. As the pulse width increases, the static unbalanced current in the switching branch gradually increases. At this time, the current sharing principle of the magnetic induction coupling coil is as follows:

[0256] From the branch current equation,

[0257] i d1 +i d2 =I L (11)

[0258] It can be known that:

[0259] 2i d1 -Δi d =I L ,2i d2 +Δi d =I L (12)

[0260] Then we can obtain:

[0261]

[0262] At this time, the branch current satisfies the equation:

[0263]

[0264] If R dson2 =R dson1 +ΔR dson Equation (14) can be simplified to:

[0265]

[0266] because

[0267]

[0268] Equation (16), after Laplace transformation, can be expressed as:

[0269]

[0270] Therefore, it can be seen that when the switch is fully turned on, the magnetizing inductance L m For unbalanced current Δi d The time constant for the inhibitory effect is:

[0271] τ2=2L m / R dson1 (18)

[0272] Example 16:

[0273] See Figures 1 to 7 A magnetic induction current sharing parallel switch pulse generator, the main technical contents of which include:

[0274] To fully verify the feasibility of the magnetic induction current sharing method based on coupled inductors proposed in this invention in suppressing transient and static unbalanced currents of parallel SiC MOSFETs in a capacitor energy storage pulse generator, a simulation model based on PSpice software was built. Figure 2 Simulation circuits, such as Figure 7 As shown in Table 1, the Pspice simulation model parameters are also shown. In the simulation circuit, small resistors of different values ​​are connected in series with the source of the SiC MOSFETs in different branches. ds The difference in on-resistance and parasitic resistance of the main discharge circuit, representing the device parameters, is reflected in the drain series inductance L of the SiC MOSFET. d This represents the inconsistency in the parasitic inductance parameters of the switching device and the main circuit. Different values ​​of drive resistor R are connected in series with the gate of the SiC MOSFET. g This represents the difference in parasitic parameters of the switch drive circuit.

[0275] Table 1 Simulation Parameters

[0276]

[0277] The Marx simulation output results for a single-stage magnetic induction current sharing system based on coupled inductors are as follows: Figure 8As shown in the figure, the simulation circuit operates with a DC input of 800V and a pulse width of 500ns. It can be seen that when the parameters of the switching devices in different branches are dispersed or the parasitic parameters of the loop lack consistency (i.e., when the parasitic resistance and stray inductance of the simulated parallel MOSFET branches are inconsistent), the parallel SiC MOSFET exhibits current imbalance during both transient and static conduction processes without current sharing measures. After adopting magnetic induction current sharing, the unbalanced current during both transient and static processes is effectively suppressed.

[0278] Example 17:

[0279] See Figures 1 to 9 A magnetic induction current sharing parallel switch pulse generator, the main technical contents of which include:

[0280] To verify the feasibility of this invention, experimental tests were conducted, and a system was built. Figure 8 The test platform shown.

[0281] Figure 9 The figure shows the experimental test results of the capacitor energy storage parallel switch pulse generator. As can be seen from the figure, without current sharing measures, a large unbalanced current appeared between the parallel switches under a pulse width of 500ns. However, after adding magnetic induction current sharing measures, a better current sharing effect was achieved.

[0282] In summary, addressing the challenge that traditional pulse generators are limited by the rated current of the switching devices used, making it difficult to achieve higher current and power outputs, this invention proposes a parallel switching pulse generation technology based on magnetic induction current sharing. By employing magnetic induction current sharing to suppress transient and static unbalanced currents during pulse generation, the problem of uneven current distribution between parallel switching devices is solved, ensuring the reliability and stability of high-current output from capacitor-based energy storage generators.

Claims

1. A magnetic induction current sharing parallel switch pulse generator, characterized in that, include: Control signal generation module, opto-isolation drive module, solid-state switch drive module, magnetic induction current sharing module, capacitor energy storage pulse output module, and load; The control signal generation module is used to generate solid-state switch control signals; The opto-isolation drive module is used to eliminate the high-potential floating of the solid-state switch; After receiving the solid-state switch control signal, the solid-state switch driver module controls the on and off of each solid-state switch in the capacitor energy storage pulse output module, as well as the on and off time. The magnetic induction current sharing module is used to eliminate uneven current between solid-state switches; The capacitor energy storage pulse output module is used to generate pulse signals and input the pulse signals into the load; The circuit topology based on the magnetic induction current sharing parallel switching pulse generator is shown below: The first and second transmission lines are symmetrically wound around both sides of the magnetic ring; Three capacitors and one solid-state switch are used as the first current branch and the second current branch; Let one end of the first transmission line be A and the other end be B; let one end of the second transmission line be C and the other end be D; the power supply... The positive terminal is E, the negative terminal is F, and the F terminal is grounded. The capacitor is connected to terminal E. Connect to terminal F; Terminals A and C are connected, and also connected to terminal E; Terminal B is connected sequentially to the first current branch and the resistor. ,resistance Rear grounding; Terminal B is connected sequentially to the first current branch and the resistor. Rear grounding; Terminal D is connected in sequence to the second current branch and the resistor. Rear grounding; Terminal D is connected in sequence to the second current branch and the resistor. ,resistance ,resistance Rear grounding; The circuit topologies of the first current branch and the second current branch are shown below: The B-end is connected to a solid-state switch. drain, solid-state switch The source is connected to the resistor. Rear grounding; The D terminal is connected to a solid-state switch. drain, solid-state switch The source is connected to the resistor. Rear grounding; The solid-state switch Drain connection capacitor Then connected to solid-state switch The source pole; The solid-state switch Drain connection capacitor Then connected to solid-state switch The gate; The solid-state switch Gate connection capacitor Then connected to solid-state switch The source pole; The solid-state switch Drain connection capacitor Then connected to solid-state switch The source pole; The solid-state switch Drain connection capacitor Then connected to solid-state switch The gate; The solid-state switch Gate connection capacitor Then connected to solid-state switch The source pole; The solid-state switch The gate is connected to resistors in sequence. ,resistance Rear grounding; The solid-state switch Gate connection resistor Then connected to solid-state switch The gate; When solid-state switch Solid-state switches When the circuit is turned on, the first current branch and the second current branch flow into two coupled coils with the same number of turns on the magnetic core, generating magnetic fluxes in opposite directions in the magnetic circuit. The magnetizing inductance of the coupling coil and leakage As shown below: （1） In the formula, This refers to the number of coil turns. , These are the outer diameter and inner diameter of the magnetic core, respectively. The difference in current within the coil; The relative permeability of the magnetic core; Permeability of free space; The current flowing through the coil; The length of the coil; Among them, the magnetic flux density in the magnetic core As shown below: （2） In the formula, Permeability; The magnetic field strength in the magnetic core; This refers to the current within the first transmission line; This refers to the current within the second transmission line; Leakage flux density in air As shown below: （3） In the formula, The strength of the magnetic field in the air; The cross-sectional area S of the magnetic core is shown below: （4） In the formula, h is the height of the magnetic core.

2. The magnetic induction current sharing parallel switch pulse generator according to claim 1, characterized in that, The solid-state switch Solid-state switches Both use MOSFET switches.

3. The magnetic induction current sharing parallel switch pulse generator according to claim 1, characterized in that, The pulse generator also includes a host computer; The host computer generates circuit parameters and transmits them to the control signal generation module, which then generates solid-state switch control signals.

4. A magnetic induction current sharing parallel switch pulse generator according to claim 1, characterized in that, The current difference between the first and second current branches generates magnetic flux in the magnetic core, inducing an electromotive force in the primary coil. The secondary coil induces an electromotive force. The electromotive force drives the unbalanced current to remain zero. As shown below: （5） In the formula, The magnetizing inductance of the magnetically coupled coil. The difference in current within the coil; t represents time.

5. A magnetic induction current sharing parallel switch pulse generator according to claim 4, characterized in that, The solid-state switch Solid-state switches The dynamic response time of the unbalanced current during the transient process of conduction. As shown below: （6） In the formula, The magnetizing inductance of the magnetically coupled coil. The leakage inductance of the magnetically coupled coil. solid-state switch The drain parasitic inductance, solid-state switch The source parasitic inductance, solid-state switch The resistance between the drain and the source, This is the variable resistor during the dynamic switching process.

6. A magnetic induction current sharing parallel switch pulse generator according to claim 4, characterized in that, The solid-state switch Solid-state switches After full conduction, the magnetizing inductor For unbalanced current The time constant for the inhibitory effect As shown below: （7） In the formula, solid-state switch The on-resistance.

7. A magnetic induction current sharing parallel switch pulse generator according to claim 1, characterized in that, The pulse output voltage and current amplitude, pulse width, and pulse frequency of the pulse generator are all adjustable.

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