Resonant mode zero voltage turn-on method for solid state power controller based on variable inductance

Abstract

The application discloses a variable inductance-based solid-state power controller resonance mode zero-voltage turn-on method, and belongs to the technical field of power electronic conversion. The method aims at the problems of large device peak stress, large heat dissipation demand and poor load adaptability during the start of a solid-state power controller. The circuit of the application comprises a resonance network composed of a variable resonance inductor and a pre-charge capacitor, a main loop power tube and an auxiliary power tube. The variable resonance inductor is used to control the resonance mode in a critical damping state for different loads with resistive, inductive and capacitive properties, so that the pre-charge capacitor is discharged without oscillation to realize zero-voltage turn-on of the main power tube and zero-current switching of the auxiliary power tube. A resonance cavity energy recovery device is arranged to transmit resonance energy to a load. The circuit significantly reduces the peak stress of the main loop device during start, reduces the switching loss of the auxiliary loop device, recovers resonance energy to the load end, reduces the heat dissipation demand, adapts to different property load scenes, and is suitable for high-power and high-reliability fields.

Description

Technical Field

[0001] This invention relates to the field of power electronics technology, and in particular to a method for zero-voltage turn-on of a solid-state power controller based on a variable inductor in resonant mode. Background Technology

[0002] Solid-state power controllers (SSPCs), as core components of next-generation intelligent power distribution systems, are driving the transformation of power distribution technology from mechanical to all-solid-state. These intelligent devices, based on semiconductor switches, achieve efficient management and protection of electrical systems through advanced power electronics technology and digital control algorithms. Compared to traditional electromechanical circuit breakers, SSPCs employ an all-solid-state design, fundamentally eliminating arcing and mechanical wear problems. Their microsecond-level response speed significantly improves protection performance, making them particularly suitable for critical applications with stringent reliability requirements. Modern SSPCs not only possess basic overcurrent and short-circuit protection functions but also achieve accurate fault diagnosis through real-time monitoring of line parameters, effectively distinguishing between normal operating condition fluctuations and genuine faults, greatly reducing the probability of malfunction.

[0003] In terms of system integration, SSPCs demonstrate exceptional adaptability and scalability. Their modular design allows for flexible configuration, meeting diverse needs ranging from simple power distribution to complex systems. High-current distribution or high-voltage isolation can be easily achieved through multi-level parallel or cascaded topologies. In the renewable energy sector, the dynamic reconfiguration capability of SSPCs provides intelligent protection solutions for photovoltaic arrays and energy storage systems, significantly improving system reliability and energy efficiency. With the maturity of wide-bandgap semiconductor technology, the new generation of SSPCs has made significant progress in switching frequency, withstand voltage, and temperature adaptability, providing new possibilities for the miniaturization and intelligent development of power electronic equipment.

[0004] Intelligentization is another important direction for the development of SSPC technology. Modern SSPCs generally integrate communication interfaces, supporting data interaction with upper-level control systems and realizing advanced functions such as remote monitoring, parameter configuration, and fault logging. This digital management approach not only improves system flexibility but also simplifies operation and maintenance processes. In the construction of the Industrial Internet of Things and smart grids, SSPCs, as key nodes, are driving the development of power distribution systems towards networking and intelligence. Although the initial cost is relatively high, the comprehensive advantages of SSPCs in terms of reliability, energy efficiency, and maintenance costs are making them increasingly widely used in high-end industries, aerospace, and other fields, demonstrating enormous development potential.

[0005] Currently, the most widely used soft-switching technology in SSPC is zero-current turn-off technology. Its core design concept is related to the soft-switching principle involved in this invention—both achieve soft-switching operation of SSPC power devices through a resonant circuit composed of a pre-charge capacitor and an inductor, so as to reduce switching losses and improve protection performance.

[0006] Currently, the most widely used soft-switching technology in SSPC is zero-current turn-off technology. Its core is to generate transient current through a resonant circuit composed of a pre-charge capacitor and an inductor, realize the commutation of the main circuit current to the auxiliary branch, and finally enable the main power transistor to turn off at the current zero crossing point, thereby reducing switching losses.

[0007] The circuit of this technology mainly includes a main circuit (the main power transistor is connected in series with the load) and an auxiliary branch (the auxiliary power transistor, pre-charge capacitor, and resonant inductor are connected in series and in parallel with the main power transistor). It also includes an energy dissipation circuit (containing a freewheeling diode and a dissipation resistor) and a varistor for voltage clamping. Its operation is as follows: under normal operating conditions, the main power transistor is turned on and the auxiliary power transistor is turned off. When a fault occurs, the auxiliary power transistor turns on, using LC resonance to generate a reverse current to offset the main circuit current, enabling the main power transistor to achieve zero-current turn-off. Subsequently, the auxiliary power transistor is turned off, and the remaining energy in the resonant branch is released through the dissipation resistor. Finally, the varistor limits the voltage peak to protect the device.

[0008] While this technology solves the problems of high turn-off losses and difficulty in extinguishing arcs in traditional DC circuit breakers, it still has significant drawbacks: First, the auxiliary power transistor does not achieve soft turn-off, and is subjected to large current and voltage stress during turn-off, resulting in high losses and failure risks; second, the energy of the resonant branch is dissipated through the resistor and cannot be recovered, reducing system energy efficiency; third, it is not adapted to different load types (capacitive, inductive, resistive, etc.), and is prone to problems such as protection delay or excessive device stress in diverse scenarios, thus having limited adaptability. Summary of the Invention

[0009] The purpose of this invention is to address the shortcomings of the prior art by proposing a zero-voltage turn-on method for a solid-state power controller based on a variable inductor. This method enables zero-voltage turn-on of the main circuit power transistor, significantly reducing the problem of high peak stress in solid-state power controller devices during capacitive load startup. Furthermore, by controlling the resonant mode of the resonant inductor and the pre-charge capacitor, soft switching of the auxiliary switching transistor is achieved, eliminating voltage and current stress and energy loss in the circuit. In addition, energy reuse technology reduces heat dissipation requirements and improves the overall efficiency of the device. By applying variable inductor technology, adaptive parameter matching is achieved for resistive, capacitive, and inductive loads, solving the problem of poor load adaptability in soft-switching circuits.

[0010] The technical solution to achieve the purpose of this invention is:

[0011] A zero-voltage turn-on method for resonant mode of a solid-state power controller based on variable inductor includes a main power channel and a resonant control circuit; the main power channel is the current path that carries the power transfer from the DC input power supply to the load, and includes:

[0012] DC input power supply V DC1 Left side line inductance L line1 Main circuit power transistor S m Right-side line inductance L line2 , load; the main circuit power transistor S m The device incorporates an anti-parallel freewheeling diode, and the load includes resistive, inductive, and capacitive loads.

[0013] The connection relationship is as follows: DC input power supply V DC The positive terminal is connected in series with the inductor L on the left side of the circuit. line1 Main circuit power transistor S m The drain of the main circuit power transistor S. m The source terminals are connected in series with the inductor L on the right side of the circuit. line2 The load, with its other end connected to a DC input power supply V. DC1 The negative terminal of the diode; the anode of the anti-parallel freewheeling diode is connected to the main circuit power transistor S. m The source is connected to the cathode, which is connected to the drain, and is used for energy follow current when the main circuit is turned off.

[0014] The resonant control circuit is an auxiliary circuit used to control the main circuit power transistor to achieve zero-voltage turn-on, and includes:

[0015] DC input power supply V DC2 Pre-charge control switch S2, pre-charge capacitor C S Resonant inductor L S Auxiliary power transistor S1; the auxiliary power transistor S1 has a built-in anti-parallel freewheeling diode;

[0016] The connection relationship is as follows: pre-charge capacitor C S One end is connected to the main circuit power transistor S m The drain and right-side line inductance L line2 The other end is connected to the resonant inductor L. S Resonant inductor L S The other end is connected to the source of the auxiliary power transistor S1, and the drain of the auxiliary power transistor S1 is connected to the load and the DC input power supply V. DC1 The negative terminal is connected; DC input power supply V DC2 The pre-charge control switch S2 is connected in parallel with the pre-charge capacitor C. S Both ends, and DC input power supply V DC2 The positive terminal and the pre-charge capacitor C S With the main circuit power transistor S m and the right-side line inductance L line2 One end is connected; the anode of the anti-parallel freewheeling diode is connected to the source of the auxiliary power transistor S1, and the cathode is connected to its drain, for reverse freewheeling in the resonant branch;

[0017] The resonant inductor Ls in the resonant control circuit uses variable inductance technology to achieve adaptive parameter matching for different load conditions (resistive, inductive, and capacitive). The resonant mode of the control circuit is in a critical damping state. The resonant inductor Ls adopts a double E-type magnetic core design. By controlling the magnetic circuit saturation of the main magnetic circuit, the relative permeability is changed, thereby controlling the magnetic reluctance of the magnetic circuit and changing the inductance value of the main magnetic circuit. Its working process is as follows: under different load conditions, bias auxiliary windings are wound on the two side posts. A bias DC current is applied to the auxiliary windings to generate DC flux in the magnetic core, changing the magnetic reluctance of the magnetic circuit to change the inductance value of the working winding, thus matching the different load conditions at the load end and controlling the resonant circuit to work in a critical damping state.

[0018] Furthermore, utilizing the pre-charge capacitor C S In the main circuit power transistor S m Before power-on, the load terminal voltage is charged to the power supply voltage. At this time, the main circuit power transistor S... m The voltage across the terminals is 0, thus enabling the main circuit power transistor S... m Zero-voltage turn-on is achieved, and zero-current turn-on and zero-current turn-off of the auxiliary power transistor S1 are realized through capacitor-inductor resonance.

[0019] Furthermore, the pre-charge capacitor C S At resonance, resonant energy is input to the load.

[0020] Furthermore, the inductive load is a load resistor connected in series with an inductor, and the capacitive load is a load resistor connected in parallel with a capacitor.

[0021] Furthermore, this includes the following modalities executed sequentially:

[0022] Mode I: This is the initial preparation mode. Auxiliary switch S2 remains closed, and the main power transistor S... m The auxiliary power transistor S1 remains off, and the power supply is used to charge the pre-charge capacitor C through the pre-charge control switch S2. S The circuit is charged to the bus voltage, so that the auxiliary power transistor S1 is subjected to the voltage of the pre-charge capacitor Cs, and the load voltage is maintained at 0.

[0023] Mode II: This is the auxiliary switch conduction mode. After Mode I is completed, the auxiliary switch S2 is turned off, and the auxiliary power transistor S1 is turned on simultaneously, utilizing the resonant inductor L. S The characteristic of resisting sudden current changes allows the current of the auxiliary power transistor S1 to rise slowly after the voltage across it drops to 0, thus achieving zero-current turn-on of the auxiliary power transistor S1.

[0024] Mode III: This is the main power transistor turn-on mode. In Mode II, after the auxiliary power transistor S1 is turned on, the pre-charge capacitor C... S With resonant inductor L sThe resonance effect causes the load terminal voltage to gradually rise to the bus voltage, and the main power transistor S... m The voltages at both ends drop to 0 simultaneously, at which point the main power transistor S controls the resonant inductor. m Turn on, enabling the main power transistor S m Zero-voltage turn-on;

[0025] Mode IV: This is the auxiliary switch turn-off mode. In Mode III, the main power transistor S... m After conduction, the resonant branch continues to resonate until the resonant current crosses zero. At this time, the auxiliary power transistor S1 is turned off, realizing the zero-current turn-off of the auxiliary power transistor S1, completing the zero-voltage turn-on process of the bidirectional solid-state power controller and entering a stable working state.

[0026] Furthermore, the phase of the current and voltage waveforms during the turn-on phase of the auxiliary power transistor S1 is controlled using the LC resonance principle. The resonant network alters the inductance value of the working winding by applying DC current to the auxiliary winding of the variable resonant inductor to generate DC magnetic flux at the side post, thus matching the resonant parameters of the circuit and controlling the resonant circuit to operate in a critical damping state. This eliminates voltage and current cross-loss and adapts to different load conditions. When the load is resistive or inductive, the capacitor in the resonant control circuit is a pre-charge capacitor C. s The inductance is a resonant inductance L. s and line inductance L line2 Furthermore, under inductive load conditions, there will also be load inductance L. load Total inductance L total Under resistive load, the resonant inductance L s and line inductance L line2 The sum is the total inductance L total Under inductive load, the resonant inductance L s Line inductance L line2 and load inductance L load The sum is the total inductance L total Total inductance L total and pre-charge capacitor C s The parameter matching control ensures the resonant mode operates in a critically damped state, allowing the pre-charge capacitor C to... s Fastest oscillation-free discharge, meeting the turn-on time limits of the bidirectional solid-state power controller and the pre-charge capacitor C. s The requirement for stable discharge; when the load is capacitive, the capacitor in the resonant control circuit is the pre-charge capacitor C. s and load capacitance C load The inductance is a resonant inductance L. s and line inductance L line Pre-charge capacitor C s Added to the load capacitance C load The total capacitance C total Total capacitance C total and resonant inductance Ls Line inductance L line The voltage and current cross-loss is eliminated by the parameter matching control circuit operating in the critical damping resonance state.

[0027] Furthermore, through the pre-charge capacitor C s and resonant inductance L s The resonant energy management mechanism enables the soft switching of the auxiliary power transistor S1 and the main power transistor S... m The soft activation operation, and using C s -L s -S1-L line -R load The energy feedback topology will precharge the capacitor C during the resonance process. s Electromagnetic energy is directionally transferred to the load R load The zero-voltage turn-on method recovers the energy injected into the resonant cavity of the main power circuit to the load side, thereby improving the overall efficiency of the device.

[0028] Furthermore, a variable inductor optimization design was achieved by using a self-looping iterative particle swarm optimization algorithm to optimize the inductance range, core loss, volume and weight, resulting in the optimal asymmetric variable inductor core structure and optimizing the variable inductor performance.

[0029] Compared with the prior art, the present invention, employing the above technical solution, has the following beneficial effects:

[0030] (1) The zero-voltage turn-on method of the solid-state power controller based on the resonant mode of the variable inductor proposed in this invention realizes the zero-voltage turn-on of the main circuit power transistor through the resonance process of the resonant inductor and the pre-charge capacitor. During the turn-on stage of the main circuit power transistor, the voltage across the main circuit power transistor drops to 0 through resonance. At this time, the main circuit power transistor is turned on to realize zero-voltage turn-on, which solves the problem of easy device failure caused by the main circuit power transistor being subjected to several times the peak when the solid-state power controller is started.

[0031] (2) The zero-voltage turn-on method of the solid-state power controller based on variable inductor proposed in this invention constructs an efficient resonant energy conversion path through the synergistic effect of resonant inductor and pre-charge capacitor. During the turn-on stage of the auxiliary power tube, the phase of the current and voltage waveforms is precisely controlled by the LC resonance principle to ensure that the switching tube is turned on under zero current conditions. At the same time, zero current turn-off is achieved during the turn-off process, thereby eliminating the voltage and current cross-loss caused by traditional hard switching, significantly reducing the loss on the power device and improving the device efficiency.

[0032] (3) The present invention uses variable inductor technology to achieve adaptive parameter matching of resonant inductor for different loads such as resistive, inductive and capacitive, so that the same circuit can automatically switch to the optimal resonant mode under different loads. The variable inductor optimization design is achieved by using a self-looping iterative trial particle swarm optimization algorithm to optimize the range of inductance, core loss and volume and weight. The optimal asymmetric variable inductor core structure is obtained and the performance of the variable inductor is optimized.

[0033] (4) This invention, through an innovative resonant energy management mechanism, enables soft switching of power devices while directionally transmitting the electromagnetic energy generated during resonance to the load end, rather than dissipating it through resistance as in traditional solutions. This energy recycling design allows for the effective recovery of energy stored in the resonant cavity. Through a special energy feedback topology, the resonant energy that would otherwise be lost as heat is reinjected into the main power circuit, which not only significantly improves the overall system efficiency but also greatly reduces the design pressure of the heat dissipation system.

[0034] (5) This invention constructs a resonant network with fast energy build-up characteristics by optimizing the matching of inductance and capacitance parameters of the resonant branch. By controlling the resonant mode to operate in the critical damping state, the millisecond-level build-up time of the traditional soft-start circuit is compressed to the order of hundreds of microseconds, and the pre-charge capacitor C is realized. s Oscillation-free and stable discharge. It retains the low-loss characteristics of soft-switching circuits while achieving a fast and stable response capability close to that of hard switches, solving the response delay problem of traditional soft-start circuits in applications requiring rapid switching, such as emergency power supplies and pulse power supplies. Attached Figure Description

[0035] Figure 1 The circuit topologies of different types of loads for the resonant mode zero-voltage turn-on method of the solid-state power controller based on variable inductor proposed in this invention are shown.

[0036] Figure 2 The pre-charge capacitor C for mode I in the embodiment. S Charging diagram;

[0037] Figure 3 This is a diagram showing the zero-current turn-on of the auxiliary power transistor S1 in mode II in the embodiment;

[0038] Figure 4 In the embodiment, the main circuit power transistor S is mode III. m Zero-voltage turn-on diagram;

[0039] Figure 5 This is the zero-current turn-off diagram of the auxiliary power transistor S1 in mode IV in the embodiment;

[0040] Figure 6 This is the power transistor drive signal under resistive load.

[0041] Figure 7 This is the soft-turn-on waveform of the main power transistor under resistive load.

[0042] Figure 8 The waveform for soft switching of the auxiliary power transistor under resistive load;

[0043] Figure 9 For the pre-charge capacitor C under resistive load s Voltage waveform;

[0044] Figure 10 This is the power transistor drive signal under inductive load.

[0045] Figure 11 This is the soft-turn-on waveform of the main power transistor under inductive load.

[0046] Figure 12 This is the soft-switching waveform of the auxiliary power transistor under inductive load.

[0047] Figure 13 For inductive loads, the pre-charge capacitor C s Voltage waveform;

[0048] Figure 14 This is the power transistor drive signal under capacitive load.

[0049] Figure 15 This is the soft-turn-on waveform of the main power transistor under capacitive load.

[0050] Figure 16 This is the soft-switching waveform of the auxiliary power transistor under capacitive load.

[0051] Figure 17 The design flow of a variable inductor based on the PSO algorithm of self-looping iterative trial;

[0052] Figure 18 The result of 300 iterations of the self-looping iterative trial algorithm is shown in the figure.

[0053] Figure 19 A three-dimensional schematic diagram of the variable inductor double E-type magnetic core and winding arrangement;

[0054] Figure 20 This is a schematic diagram of the magnetic circuit of a variable inductor and the coupling between magnetic flux and current.

[0055] Figure 21 This is a flowchart of the variable inductor process. Detailed Implementation

[0056] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0057] A resonant mode zero-voltage turn-on method for a solid-state power controller based on variable inductors is proposed, with circuit topologies for different loads as follows: Figure 1 As shown. It includes a main power channel and a resonant control circuit; the main power channel is the current path that carries the power transfer from the DC input power source to the load, and includes:

[0058] DC input power supply V DC1 Left side line inductance L line1 Main circuit power transistor S m Right-side line inductance L line2 , load; the main circuit power transistor S m The device incorporates an anti-parallel freewheeling diode, and the load includes resistive, inductive, and capacitive loads.

[0059] The connection relationship is as follows: DC input power supply V DC The positive terminal is connected in series with the inductor L on the left side of the circuit. line1 Main circuit power transistor S m The drain of the main circuit power transistor S. m The source terminals are connected in series with the inductor L on the right side of the circuit. line2 The load, with its other end connected to a DC input power supply V. DC1 The negative terminal of the diode; the anode of the anti-parallel freewheeling diode is connected to the main circuit power transistor S. m The source is connected to the cathode, which is connected to the drain, and is used for energy follow current when the main circuit is turned off.

[0060] The resonant control circuit is an auxiliary circuit used to control the main circuit power transistor to achieve zero-voltage turn-on, and includes:

[0061] DC input power supply V DC2 Pre-charge control switch S2, pre-charge capacitor C S Resonant inductor L S Auxiliary power transistor S1; the auxiliary power transistor S1 has a built-in anti-parallel freewheeling diode;

[0062] The connection relationship is as follows: pre-charge capacitor C S One end is connected to the main circuit power transistor S m The drain and right-side line inductance L line2 The other end is connected to the resonant inductor L. S Resonant inductor L SThe other end is connected to the source of the auxiliary power transistor S1, and the drain of the auxiliary power transistor S1 is connected to the load and the DC input power supply V. DC1 The negative terminal is connected; DC input power supply V DC2 The pre-charge control switch S2 is connected in parallel with the pre-charge capacitor C. S Both ends, and DC input power supply V DC2 The positive terminal and the pre-charge capacitor C S With the main circuit power transistor S m and the right-side line inductance L line2 One end is connected; the anode of the anti-parallel freewheeling diode is connected to the source of the auxiliary power transistor S1, and the cathode is connected to its drain, for reverse freewheeling in the resonant branch;

[0063] The resonant inductor Ls in the resonant control circuit uses variable inductance technology to achieve adaptive parameter matching for different load conditions, such as resistive, inductive, and capacitive loads. The resonant mode of the control circuit is in a critical damping state, enabling the pre-charge capacitor CS to achieve the fastest oscillation-free discharge. This meets the requirements of the solid-state power controller for turn-on time and the stable discharge of the pre-charge capacitor CS, allowing the same circuit to automatically switch to the optimal resonant mode under different loads. This retains the low stress and low loss characteristics of soft-switching circuits while achieving a fast and stable response capability close to that of hard switching.

[0064] Furthermore, utilizing the pre-charge capacitor C S In the main circuit power transistor S m Before activation, the voltage across its terminals is reduced to 0 to achieve the desired effect for the main circuit power transistor S. m Zero-voltage turn-on is achieved, and zero-current turn-on and zero-current turn-off of the auxiliary power transistor S1 are realized through capacitor-inductor resonance. The entire process of S1 can achieve complete soft switching, reducing turn-on and turn-off losses. In addition, the energy of the resonant branch is basically transferred to the load during the resonance process. Therefore, the soft-turn-on circuit has very low losses, which is beneficial to improving equipment efficiency.

[0065] Furthermore, the pre-charge capacitor C S At resonance, the resonant energy is input to the DC input power supply V. DC Or the load terminal; the inductive load is the load resistor connected in series with an inductor, and the capacitive load is the load resistor connected in parallel with a capacitor.

[0066] Furthermore, this includes the following modalities executed sequentially:

[0067] Mode I: This is the initial preparation mode. Auxiliary switch S2 remains closed, and the main power transistor S... m The auxiliary power transistor S1 remains off, and the power supply is used to charge the pre-charge capacitor C through the pre-charge control switch S2. S The circuit is charged to the bus voltage, so that the auxiliary power transistor S1 is subjected to the voltage of the pre-charge capacitor Cs, and the load voltage is maintained at 0.

[0068] Mode II: This is the auxiliary switch conduction mode. After Mode I is completed, the auxiliary switch S2 is turned off, and the auxiliary power transistor S1 is turned on simultaneously, utilizing the resonant inductor L. S The characteristic of resisting sudden current changes allows the current of the auxiliary power transistor S1 to rise slowly after the voltage across it drops to 0, thus achieving zero-current turn-on of the auxiliary power transistor S1.

[0069] Mode III: This is the main power transistor turn-on mode. In Mode II, after the auxiliary power transistor S1 is turned on, the pre-charge capacitor C... S With resonant inductor L s The resonance effect causes the load terminal voltage to gradually rise to the bus voltage, and the main power transistor S... m The voltages at both ends drop to 0 simultaneously, at which point the main power transistor S controls the resonant inductor. m Turn on, enabling the main power transistor S m Zero-voltage turn-on;

[0070] Mode IV: This is the auxiliary switch turn-off mode. In Mode III, the main power transistor S... m After conduction, the resonant branch continues to resonate until the resonant current crosses zero. At this time, the auxiliary power transistor S1 is turned off, realizing the zero-current turn-off of the auxiliary power transistor S1, completing the zero-voltage turn-on process of the bidirectional solid-state power controller and entering a stable working state.

[0071] Furthermore, the phase of the current and voltage waveforms during the turn-on phase of the auxiliary power transistor S1 is controlled using the LC resonance principle. The resonant network eliminates voltage and current cross-loss through matching parameters and adapts to different load conditions. When the load is resistive or inductive, the capacitor in the resonant control circuit is the pre-charge capacitor C. s The inductance is a resonant inductance L. s and line inductance L line2 Furthermore, in the case of an inductive load, there will also be a load inductance L. load Total inductance L total Total inductance L total and pre-charge capacitor C s The parameter matching control ensures the resonant mode operates in a critically damped state, allowing the pre-charge capacitor C to... s Fastest oscillation-free discharge, meeting the turn-on time limits of the bidirectional solid-state power controller and the pre-charge capacitor C. s The requirement for stable discharge; when the load is capacitive, the capacitor in the resonant control circuit is the pre-charge capacitor C. s and load capacitance C load Total capacitance C total The inductance is a resonant inductance L. s and line inductance L line Total capacitance C total and resonant inductance Ls Line inductance L line The parameter matching control circuit operates in the critical damping resonance state to eliminate voltage and current cross-loss.

[0072] Furthermore, through the pre-charge capacitor C s and resonant inductance L s The resonant energy management mechanism enables the soft switching of the auxiliary power transistor S1 and the main power transistor S... m The soft activation operation, and using C s -L s -S1-L line -R load The energy feedback topology will precharge the capacitor C during the resonance process. s Electromagnetic energy is directionally transferred to the load R load The zero-voltage turn-on method recovers the energy injected into the resonant cavity of the main power circuit to the load side, thereby improving the overall efficiency of the device.

[0073] Furthermore, by optimizing the inductance and capacitance parameter matching of the resonant branch to construct a fast energy-establishing resonant network, and controlling the resonant mode to operate in a critically damped state, the circuit startup time is compressed to the order of hundreds of microseconds, and the pre-charge capacitor C is realized. s Oscillation-free stable discharge; the resonant network adopts a dynamic parameter adjustment mechanism to achieve a fast response capability close to that of a hard switch while maintaining the low loss characteristics of soft switching.

[0074] To verify the validity of this invention patent, simulation verification was performed using the SSPC operating parameters in Table 1 and the SiC MOSFET parameters in Table 2.

[0075] Table 1 SSPC Operating Parameters

[0076]

[0077] Table 2 C3M0025065D Parameter Table

[0078]

[0079] Circuit simulation results are as follows Figures 6 to 9 As shown. Figure 7 The figure shows the drain current and drain-source voltage waveforms of the main circuit power transistor under resistive load. The waveforms show the main circuit power transistor S m The property of zero-voltage turn-on; Figure 8 The figure shows the drain current and drain-source voltage waveforms of the auxiliary power transistor under resistive load. The waveforms demonstrate the soft-switching nature of the auxiliary power transistor S1. Figure 9 The figure shows the pre-charge capacitor C under resistive load. s The voltage waveform diagram shows that as the pre-charge capacitor C...s The voltage drops, and the resonant energy stored in the capacitor is fed back to the load through the energy feedback loop; this reflects the advantages of the present invention, which reduces the turn-on stress of the main circuit power transistor and the switching loss and heat dissipation requirements of the auxiliary circuit power transistor, and controls the resonant process in a critical damping state to balance fast response and stability, as well as the advantages of energy feedback to improve device efficiency.

[0080] Since the SSPC load terminal also has capacitive and inductive loads in addition to resistive loads, simulation analysis is performed for both cases. The simulation parameters are set according to Table 1. The inductive load is a load resistor connected in series with a 2mH inductor, and the capacitive load is a load resistor connected in parallel with a 100uF capacitor. An inductive load is equivalent to increasing the resonant inductance L. s For resistive loads, the variable inductance value is adjusted by matching parameters to make the resonant mode operate in a critically damped state. Similarly, when the load is capacitive, adjusting the variable inductance value controls the resonant mode to operate in a critically damped state, achieving soft turn-on of the main circuit power transistor. The specific simulation circuit and simulation waveforms for inductive loads are as follows: Figure 10 , Figure 11 , Figure 12 , Figure 13 As shown; Figure 11 , 12 The figures shown are the drain current and drain-source voltage waveforms of the main circuit power transistor and the auxiliary power transistor under inductive load. The waveforms show the drain current and drain-source voltage waveforms of the main circuit power transistor S. m The soft-switching properties of the auxiliary power transistor S1 reflect the superiority of the proposed soft-switching method in reducing switching losses and heat dissipation requirements. The capacitive load simulation circuit and simulation waveforms are shown below. Figure 14 , Figure 15 , Figure 16 As shown. Figure 15 , 16 The figures shown are the drain current and drain-source voltage waveforms of the main circuit power transistor and the auxiliary power transistor under capacitive load. The waveforms show the drain current and drain-source voltage waveforms of the main circuit power transistor S. m The soft-switching properties of the auxiliary power transistor S1 reflect the superiority of the soft-switching proposed in this invention in reducing switching losses and heat dissipation requirements. Furthermore, the above waveforms reflect the superiority of the strong load adaptability proposed in this invention, which can achieve the soft-switching effect in resistive, inductive, and capacitive loads.

[0081] Simulation results show that the zero-voltage turn-on circuit proposed in this invention enables the main circuit power transistor S... mThe soft turn-on and soft switching of the auxiliary circuit power transistor S1 reduce the turn-on and turn-off losses of the power transistor, optimize the stress on the switching transistor, and the capacitor voltage drops slightly when the resonant current is generated, with its energy being mainly transferred to the load. Compared with the existing SSPC soft turn-off technology, this improves the device efficiency. The overall turn-on time of the circuit is around 100µs, which meets the current design requirements of SSPC.

[0082] Simulations were performed for three different load conditions: resistive, inductive, and capacitive. The simulation results show that the results for resistive and inductive loads are similar, while the results for capacitive loads are significantly different. This is because an inductive load is equivalent to a resistive load with increased line inductance, affecting only parameters such as the resonant period. However, with a capacitive load, the capacitor at the load end is equivalent to a short circuit at resonance, and the resonant current needs to continuously charge the capacitor, making it difficult to quickly raise the load end voltage to the bus voltage level. Therefore, the resonant period is longer under the capacitive load condition, approximately 2-3 times that of resistive and inductive loads. However, the overall time is still within the microsecond range and does not affect the normal commissioning of the SSPC.

[0083] The flowchart of the variable inductor optimization design based on the self-looping iterative trial particle swarm optimization algorithm to achieve multi-objective optimization of inductance range, core loss, and volume and weight is as follows: Figure 17 As shown, the three core cross-sectional area parameters of the "double-E" core, namely the central column and the two bilateral columns, are used as optimization variables. The nonlinear parameters obtained by the self-loop trial algorithm are used to model the inductance value variation range, the magnetic induction intensity of the bilateral columns, and various losses. The weights of the model numerical results are assigned, and a value function is constructed as the optimal position of the particles. By setting a large number of particles and multiple iterative calculations, the optimal core cross-sectional area parameters that take into account the large inductance variation range, the symmetry of the magnetic induction intensity of the bilateral columns, and the small total loss are found. Figure 18 The graph shows the results of the self-looping iterative trial algorithm after 300 iterations. After 300 iterations, the value function reaches a maximum of 10, and nearly 100 particles fall at the same point. It can be considered that the optimal core cross-sectional area parameter has been found at the maximum value function, thus completing the variable inductor optimization design.

[0084] Figure 19 , 20 This is a diagram of the variable inductor model used in this invention. Figure 21 This is a flowchart illustrating the operation of the variable inductor used in this invention. N 1. N 2 and N 3 represents the number of turns in the central column main winding and the auxiliary windings on both side columns, respectively. N 2 and N 3. Same as above, and the winding is reversed. Φ DC and Φ ACThese represent the bias DC current. I DC The generated magnetic flux and the alternating current of the main winding i AC The generated magnetic flux. The variable inductor adopts a "double-E" core design, which changes the relative permeability by controlling the magnetic circuit saturation of the main magnetic circuit, thereby controlling the magnetic reluctance of the magnetic circuit and changing the inductance value of the main magnetic circuit. Its working process is as follows: under different load conditions, bias auxiliary windings are wound on the two side posts, and a bias DC current is applied to the auxiliary windings to generate DC magnetic flux in the core, changing the magnetic reluctance of the magnetic circuit to change the inductance value of the working winding, matching different load conditions at the load end and controlling the resonant circuit to operate in a critical damping state.

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for zero-voltage turn-on of a solid-state power controller based on a variable inductor in resonant mode, characterized in that, It includes a main power channel and a resonant control circuit; the main power channel is the current path that carries the power transfer from the DC input power supply to the load, and includes: DC input power supply V DC1 Left side line inductance L line1 Main circuit power transistor S m Right-side line inductance L line2 , load; the main circuit power transistor S m The device incorporates an anti-parallel freewheeling diode, and the load includes resistive, inductive, and capacitive loads. The connection relationship is as follows: DC input power supply V DC1 The positive terminal is connected in series with the inductor L on the left side of the circuit. line1 Main circuit power transistor S m The drain of the main circuit power transistor S. m The source terminals are connected in series with the inductor L on the right side of the circuit. line2 The load, with its other end connected to a DC input power supply V. DC1 The negative terminal of the diode; the anode of the anti-parallel freewheeling diode is connected to the main circuit power transistor S. m The source is connected to the cathode, which is connected to the drain, and is used for energy follow current when the main circuit is turned off. The resonant control circuit is an auxiliary circuit used to control the main circuit power transistor to achieve zero-voltage turn-on, and includes: DC input power supply V DC2 Pre-charge control switch S2, pre-charge capacitor C S Resonant inductor L S Auxiliary power transistor S1; the auxiliary power transistor S1 has a built-in anti-parallel freewheeling diode; The connection relationship is as follows: pre-charge capacitor C S One end is connected to the main circuit power transistor S m The drain and right-side line inductance L line2 The other end is connected to the resonant inductor L. S Resonant inductor L S The other end is connected to the source of the auxiliary power transistor S1, and the drain of the auxiliary power transistor S1 is connected to the load and the DC input power supply V. DC1 The negative terminal is connected; DC input power supply V DC2 The pre-charge control switch S2 is connected in parallel with the pre-charge capacitor C. S Both ends, and DC input power supply V DC2 The positive terminal and the pre-charge capacitor C S With the main circuit power transistor S m and the right-side line inductance L line2 One end is connected; the anode of the anti-parallel freewheeling diode is connected to the source of the auxiliary power transistor S1, and the cathode is connected to its drain, for reverse freewheeling in the resonant branch; The resonant inductor Ls in the resonant control circuit uses variable inductance technology to achieve adaptive parameter matching for different load conditions such as resistive, inductive and capacitive loads. The resonant mode of the control circuit is in the critical damping state. The resonant inductor Ls adopts a double E-type magnetic core design. By controlling the magnetic circuit saturation of the main magnetic circuit, the relative permeability is changed, thereby controlling the magnetic reluctance of the magnetic circuit and changing the inductance value of the main magnetic circuit. Its working process is as follows: under different load conditions, bias auxiliary windings are wound on two side posts, bias DC current is applied to the auxiliary windings, DC flux is generated in the magnetic core, the magnetic reluctance of the magnetic circuit is changed to change the inductance value of the working winding, and the resonant circuit is controlled to work in the critical damping state to match the different load conditions at the load end.

2. The method for zero-voltage turn-on of a solid-state power controller based on a variable inductor in resonant mode according to claim 1, characterized in that, Using pre-charge capacitor C S In the main circuit power transistor S m Before powering on, charge the load terminal voltage to the DC input power supply V. DC2 The voltage at this time, the main circuit power transistor S m The voltage across the terminals is 0, thus enabling the main circuit power transistor S... m Zero-voltage turn-on is achieved, and zero-current turn-on and zero-current turn-off of the auxiliary power transistor S1 are realized through capacitor-inductor resonance.

3. The method for zero-voltage turn-on of a solid-state power controller based on a variable inductor in resonant mode according to claim 1, characterized in that, The pre-charged capacitor C S At resonance, resonant energy is input to the load.

4. The method for zero-voltage turn-on of a solid-state power controller based on a variable inductor in resonant mode according to claim 1, characterized in that, The inductive load is a load resistor connected in series with an inductor, and the capacitive load is a load resistor connected in parallel with a capacitor.

5. The method for zero-voltage turn-on of a solid-state power controller based on a variable inductor in resonant mode according to claim 1, characterized in that, The following modalities are executed sequentially: Mode I: This is the initial preparation mode. Auxiliary switch S2 remains closed, and the main power transistor S... m And the auxiliary power transistor S1 remains off, utilizing the DC input power supply V DC2 The pre-charge capacitor C is pre-charged via the pre-charge control switch S2. S The circuit is charged to the bus voltage, so that the auxiliary power transistor S1 is subjected to the voltage of the pre-charge capacitor Cs, and the load voltage is maintained at 0. Mode II: This is the auxiliary switch conduction mode. After Mode I is completed, the auxiliary switch S2 is turned off, and the auxiliary power transistor S1 is turned on simultaneously, utilizing the resonant inductor L. S The characteristic of resisting sudden current changes allows the current of the auxiliary power transistor S1 to rise slowly after the voltage across it drops to 0, thus achieving zero-current turn-on of the auxiliary power transistor S1. Mode III: This is the main power transistor turn-on mode. In Mode II, after the auxiliary power transistor S1 is turned on, the pre-charge capacitor C... S With resonant inductor L s The resonance effect causes the load terminal voltage to gradually rise to the bus voltage, and the main power transistor S... m The voltages at both ends drop to 0 simultaneously, at which point the main power transistor S controls the resonant inductor. m Turn on, enabling the main power transistor S m Zero-voltage turn-on; Mode IV: This is the auxiliary switch turn-off mode. In Mode III, the main power transistor S... m After conduction, the resonant branch continues to resonate until the resonant current crosses zero. At this time, the auxiliary power transistor S1 is turned off, realizing the zero-current turn-off of the auxiliary power transistor S1, completing the zero-voltage turn-on process of the bidirectional solid-state power controller and entering a stable working state.

6. The method for zero-voltage turn-on of a solid-state power controller based on a variable inductor in resonant mode according to claim 1, characterized in that, The phase of the current and voltage waveforms during the turn-on phase of the auxiliary power transistor S1 is controlled using the LC resonance principle. The resonant network changes the inductance value of the working winding by applying DC current to the auxiliary winding of the variable resonant inductor to generate DC magnetic flux at the side post. This allows the resonant circuit to operate in a critical damping state under different load conditions, eliminating voltage and current cross-loss and adapting to different load conditions. When the load is resistive or inductive, the capacitor in the resonant control circuit is the pre-charge capacitor C. s The inductance is a resonant inductance L. s and line inductance L line2 Furthermore, in the case of inductive loads, it also includes the load inductance L. load Under resistive load, the resonant inductance L s and line inductance L line2 The sum is the total inductance L total Under inductive load, the resonant inductance L s Line inductance L line2 and load inductance L load The sum is the total inductance L total Total inductance L total and pre-charge capacitor C s The parameter matching control ensures the resonant mode operates in a critically damped state, allowing the pre-charge capacitor C to... s Fastest oscillation-free discharge, meeting the turn-on time limits of the bidirectional solid-state power controller and the pre-charge capacitor C. s The requirement for stable discharge; when the load is capacitive, the capacitor in the resonant control circuit is the pre-charge capacitor C. s and load capacitance C load The inductance is a resonant inductance L. s and line inductance L line2 Pre-charge capacitor C s Added to the load capacitance C load The total capacitance C total Total capacitance C total and resonant inductance L s Line inductance L line2 The voltage and current cross-loss is eliminated by the parameter matching control circuit operating in the critical damping resonance state.

7. The method for zero-voltage turn-on of a solid-state power controller based on a variable inductor in resonant mode according to claim 1, characterized in that, Through the pre-charge capacitor C s and resonant inductance L s The resonant energy management mechanism enables the soft switching of the auxiliary power transistor S1 and the main power transistor S... m The soft activation operation, and using C s -L s -S1-L line2 -R load The energy feedback topology will precharge the capacitor C during the resonance process. s Electromagnetic energy is directionally transferred to the load R load The zero-voltage turn-on method recovers the energy injected into the resonant cavity of the main power circuit to the load side, thereby improving the overall efficiency of the device.

8. The method for zero-voltage turn-on of a solid-state power controller based on a variable inductor in resonant mode according to claim 1, characterized in that, By employing a self-looping iterative particle swarm optimization algorithm, the variable inductor is optimized for multiple objectives, including inductance range, core loss, and volume and weight. This yields the optimal asymmetric variable inductor core structure and optimizes the variable inductor performance.

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