All-solid-state parameter-adjustable energy recovery excitation source

Abstract

The full solid-state parameter adjustable energy recovery excitation source comprises a charging circuit, a main power circuit and a load circuit. The coil current parameters can be flexibly regulated by the working time sequence of each stage switch. The number of discharge modules contained in the full solid-state parameter adjustable energy recovery excitation source is flexibly adjustable, the structure is simple and reliable, the corresponding module number can be matched according to the application requirement, and the cost is reduced. The full solid-state parameter adjustable energy recovery excitation source can feed back the load energy to each stage capacitor through the front-end commutation switch and the energy feedback diode, so that the system energy utilization efficiency is improved. The full solid-state parameter adjustable energy recovery excitation source can break through the limitation that the traditional topology can only adjust the pulse front edge or a single parameter by controlling the input time sequence of each module, and fine and multi-dimensional control of the whole pulse waveform is realized.

Description

Technical Field

[0001] This invention relates to the field of pulsed power technology, and more specifically to an all-solid-state parameter-adjustable energy recovery excitation source. Background Technology

[0002] Pulsed power technology is a key technology that releases high-power pulse energy in an extremely short time through a "store first, compress later" approach. This technology has developed rapidly over the past fifty years, achieving a significant leap in its applications from cutting-edge defense technologies (such as controlled nuclear fusion research and electromagnetic railguns) to a wide range of civilian and industrial fields. Today, this technology has successfully penetrated multiple industries, including environmental protection, biomedicine, and food processing, demonstrating its strong technological scalability and practical value.

[0003] In the biomedical field, pulsed magnetic field therapy has become a research hotspot due to its safety and non-invasiveness. On the one hand, pulsed magnetic fields with specific parameters can be used for non-invasive nerve stimulation (transcranial magnetic stimulation) to treat neuropathic pain, depression, and other diseases; on the other hand, higher-intensity pulsed magnetic fields can alter cell membrane permeability (magnetoporeception), providing new pathways for vaccine delivery and cancer treatment. Studies have shown that the biological effects of pulsed magnetic fields are jointly determined by their simultaneously contained magnetic field component and induced electric field component. To accurately induce target biological effects and avoid side effects, it is necessary to coordinate and precisely control core parameters such as magnetic field strength and rate of change. This characteristic places extremely stringent technical requirements on the output control capability of the pulse excitation source.

[0004] In the development of pulsed magnetic field excitation sources, a series of technical problems have gradually emerged, restricting their performance and applications. Early single-transient magnetic field excitation sources (sTMS) suffered from fundamental defects such as a single output waveform (only capable of outputting a single-phase sine pulse), huge energy loss, and difficulty in repetitive frequency operation. Subsequent attempts to improve magnetic field strength and rate of change employed alternatives such as gas spark gap switches, but these introduced new problems of output waveform oscillation and difficulty in control. With the application of fully controllable solid-state switches (such as IGBTs), although waveform modulation (e.g., with flat-top pulses) was achieved, the pulse width and output voltage adjustment range remained limited due to the single energy storage capacitor.

[0005] In the pursuit of waveform diversity and energy efficiency, typical topologies such as the Controllable Pulse Transient Magnetic Stimulation (cTMS) series have exposed more key bottlenecks. For example, in cTMS1 topologies, residual coil energy is dissipated through resistance after the switch is turned off, resulting in significant energy loss. Although subsequent topologies such as cTMS2 and cTMS3 have greatly improved energy efficiency through energy recovery mechanisms, their output current change rate is generally limited by the withstand voltage performance of power switching devices, which hinders their expansion into high-requirement fields such as magnetic perforation. In recent years, while modular design has improved the flexibility of output control, it has brought about problems such as complex system structure, a large number of switches, and high cost. The latest energy-saving excitation source based on the Marx principle, although achieving energy recovery and multi-level output on the rising edge, is limited in high-precision applications due to its single energy recovery mode and inability to flexibly modulate the falling edge of the pulse. Summary of the Invention

[0006] The purpose of this invention is to provide a fully solid-state parameter adjustable energy recovery excitation source, including: a charging circuit, a main power circuit, and a load circuit.

[0007] The charging circuit is used to store energy from the external power source into the energy storage capacitor of the main power circuit.

[0008] The main power circuit is used to release the energy stored in the charging circuit to the load circuit and output pulse current on the load inductor of the load circuit, thereby generating a magnetic field.

[0009] The main power circuit is used to provide a freewheeling path for the residual current in the load circuit.

[0010] The main power circuit is used to recover the energy stored in the load circuit into the energy storage capacitor.

[0011] Furthermore, the circuit topology of the all-solid-state parameter-tunable energy recovery excitation source is shown below:

[0012] DC power supply The negative terminal is grounded, and the positive terminal is connected in series with a resistor. Connected to diode The anode.

[0013] diode The cathode is connected to the diode. The anode is k, which is the index of the energy storage capacitor, and k = 1, 2, ..., n-1, where n is the total number of energy storage capacitors.

[0014] diode The cathode is connected to the diode. anode, diode Cathode series energy storage capacitor Connected to diode The anode is denoted by s, where s is the index of the energy storage capacitor, and s = 1, 2, ..., n.

[0015] diode The cathode is connected to the diode. cathode, diode The anode is connected to the switching transistor. collector, switching transistor The emitter is connected to the diode. The anode.

[0016] diode The cathode is connected to the switching transistor. collector, switching transistor The emitter is connected to the diode. The cathode.

[0017] diode The cathode is connected to the switching transistor. The collector.

[0018] diode The cathode is grounded.

[0019] diode The anodes are connected in series with load resistors. and load inductance Grounded afterward.

[0020] Furthermore, the switching transistor and switching transistor All use IGBT switches with the gates floating.

[0021] Furthermore, the working process of the all-solid-state parameter adjustable energy recovery excitation source includes a charging stage, a discharging stage, a commutation stage, and a freewheeling stage.

[0022] Furthermore, when the all-solid-state parameter-adjustable energy recovery excitation source is operating in the charging phase, the switching transistor... In the off state, the switching transistor On, DC power supply Energy through resistance ,diode ,diode ,diode Switching transistor Stored in energy storage capacitor middle.

[0023] Furthermore, when the all-solid-state parameter-adjustable energy recovery excitation source is operating in the discharge phase, the switching transistor... and switching transistor On, energy storage capacitor The energy stored in it is transmitted through the switching transistor. and switching transistor Release to load resistor and load inductance superior.

[0024] Furthermore, when the all-solid-state parameter-adjustable energy recovery excitation source operates in the commutation phase, the switching transistor... and switching transistor Both are in the off state, load inductance The energy stored in it is transmitted through diodes ,diode Recovered into energy storage capacitors middle.

[0025] Furthermore, when the all-solid-state parameter-adjustable energy recovery excitation source operates in the freewheeling phase, the switching transistor... In the off state, the switching transistor On, load inductance The residual current in the circuit passes through the switching transistor. ,diode To continue streaming.

[0026] Furthermore, the parameters of the pulse current include current amplitude, pulse frequency, and pulse width.

[0027] The pulse current has an amplitude range of 0-2500 A, a pulse frequency of 0-10 Hz, and a pulse width of 0-200 μs.

[0028] Furthermore, the parameters of the pulse current are controlled by adjusting the switching transistor. Trigger delay, switching transistor On-time and energy storage capacitor The voltage at both ends is adjusted.

[0029] The switching transistor The trigger delay and the duration of the falling edge of the pulse current are positively correlated.

[0030] The switching transistor The conduction time is positively correlated with the rising edge duration of the pulse current.

[0031] The energy storage capacitor The voltage across the terminals is positively correlated with the amplitude of the pulse current.

[0032] The technical effectiveness of this invention is undeniable. This invention proposes a fully solid-state, parameter-adjustable energy recovery excitation source, systematically analyzes its working principle and output performance, and constructs a three-stage modular excitation source experimental platform through core component selection and parameter design. Based on measured data of capacitor voltage and coil current during pulse output, the system's energy efficiency is quantitatively calculated. The results show that within a switching conduction time range of 25 μs to 100 μs, the system can flexibly modulate various waveforms such as triangular waves and exponential waves. Furthermore, the coil current control capability of the three-stage excitation source physical platform was tested, successfully outputting a stepped pulse waveform with multi-level current change rates and voltage characteristics. The test results verify that this excitation source can achieve flexible control of the output coil pulse current across the entire frequency band by controlling the timing of the control circuit modules, thus providing technical support for research on diverse pulsed electromagnetic biological effects.

[0033] This invention proposes a multi-stage controllable pulsed magnetic field excitation source based on modular circuits. Each stage of this excitation source requires only two control switches, and the coil current parameters can be flexibly adjusted by the working sequence of each stage of the switches, which has the following advantages:

[0034] 1. The maximum magnetic field change rate of the modular, parameter-adjustable energy-harvesting pulsed magnetic field excitation source is determined by the number of cascaded discharge modules, and the appropriate number of modules can be matched according to application requirements. The all-solid-state parameter-adjustable energy recovery excitation source proposed in this invention has a flexible and adjustable number of discharge modules, a simple and reliable structure, and can be matched with the appropriate number of modules according to application requirements, which helps to reduce costs.

[0035] 2. Modular parameter-adjustable pulsed magnetic field excitation source can significantly improve system energy utilization efficiency by controlling the switch, thereby reducing internal circuit losses. The all-solid-state parameter-adjustable energy recovery excitation source proposed in this invention can feed load energy back to capacitors at each stage through the front-end commutation switch and the energy feeding diode, which is beneficial to improving system energy utilization efficiency.

[0036] 3. The modular, parameter-adjustable energy-recovery pulse magnetic field excitation source can control the timing of circuit module inputs, enabling flexible regulation of the output coil pulse current across the entire waveform. The all-solid-state, parameter-adjustable energy recovery excitation source proposed in this invention overcomes the limitations of traditional topologies, which often only adjust the pulse leading edge or a single parameter, by controlling the input timing of each module. This achieves precise, multi-dimensional control of the entire pulse waveform. Attached Figure Description

[0037] Figure 1 Schematic diagram of the topology of an all-solid-state parameter-tunable energy recovery excitation source;

[0038] Figure 2 This is a schematic diagram of the switching drive timing for each mode of the excitation source; Figure 2(a) is a schematic diagram of the working timing of the triangle wave output mode switch; Figure 2 (b) is a schematic diagram of the operating timing of the exponential wave output mode switch;

[0039] Figure 3 A schematic diagram of the circuit state during the charging phase of the excitation source;

[0040] Figure 4 This is a schematic diagram of the circuit state during the discharge phase of the excitation source;

[0041] Figure 5 This is a schematic diagram of the circuit state during the commutation stage of the excitation source;

[0042] Figure 6 This is a schematic diagram of the circuit state during the freewheeling phase of the excitation source.

[0043] Figure 7 This is a schematic diagram of a switch buffer circuit.

[0044] Figure 8 A schematic diagram of the implementation scheme for the switch buffer circuit;

[0045] Figure 9 A schematic diagram of a three-stage controllable modular pulsed magnetic field excitation source platform;

[0046] Figure 10 Schematic diagram of the excitation source output waveform under different capacitor discharge voltage conditions; Figure 10 (a) is a schematic diagram of the coil current; Figure 10 (b) is a schematic diagram of the coil voltage;

[0047] Figure 11 A schematic diagram of the excitation source output waveforms corresponding to different switch conduction times; Figure 11 (a) is a schematic diagram of the coil current; Figure 11 (b) is a schematic diagram of the coil voltage;

[0048] Figure 12 A schematic diagram of the switching timing corresponding to the multi-stage stepped output mode of the excitation source; Figure 12 (a) is a schematic diagram of an ascending stepped wave; Figure 12 (b) is a schematic diagram of a descending stepped wave;

[0049] Figure 13 A schematic diagram of a multi-stage stepped output mode for the excitation source; Figure 13 (a) is a schematic diagram of an ascending stepped wave; Figure 13 (b) is a schematic diagram of a descending stepped wave;

[0050] In the diagram: 1. DC power supply; 2. Current sensor; 3. Load coil; 4. Voltage probe; 5. Oscilloscope; 6. FPGA control system; 7. Buffer circuit; 8. Discharge capacitor; 9. IGBT switch; 10. Current limiting resistor; 11. Three-level controllable modular pulse magnetic field generator; 12. Switching power supply; 13. Buffer capacitor; 14. IGBT drive circuit; 15. Buffer diode; 16. Buffer resistor. Detailed Implementation

[0051] 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.

[0052] Example 1:

[0053] See Figures 1 to 13 The fully solid-state adjustable energy recovery excitation source includes: charging circuit, main power circuit, and load circuit.

[0054] The charging circuit is used to store energy from the external power source into the energy storage capacitor of the main power circuit.

[0055] The main power circuit is used to release the energy stored in the charging circuit to the load circuit and output pulse current on the load inductor of the load circuit, thereby generating a magnetic field.

[0056] The main power circuit is used to provide a freewheeling path for the residual current in the load circuit.

[0057] The main power circuit is used to recover the energy stored in the load circuit into the energy storage capacitor.

[0058] Example 2:

[0059] The all-solid-state parameter-adjustable energy recovery excitation source, the main technical content of which is described in Embodiment 1, and further, the circuit topology of the all-solid-state parameter-adjustable energy recovery excitation source is as follows:

[0060] DC power supply The negative terminal is grounded, and the positive terminal is connected in series with a resistor. Connected to diode The anode.

[0061] diode The cathode is connected to the diode. The anode is k, which is the index of the energy storage capacitor, and k = 1, 2, ..., n-1, where n is the total number of energy storage capacitors.

[0062] diode The cathode is connected to the diode. anode, diode Cathode series energy storage capacitor Connected to diode The anode is denoted by s, where s is the index of the energy storage capacitor, and s = 1, 2, ..., n.

[0063] diode The cathode is connected to the diode. cathode, diode The anode is connected to the switching transistor. collector, switching transistor The emitter is connected to the diode. The anode.

[0064] diode The cathode is connected to the switching transistor. collector, switching transistor The emitter is connected to the diode. The cathode.

[0065] diode The cathode is connected to the switching transistor. The collector.

[0066] diode The cathode is grounded.

[0067] diode The anodes are connected in series with load resistors. and load inductance Grounded afterward.

[0068] Example 3:

[0069] The all-solid-state parameter-adjustable energy recovery excitation source, the main technical contents of which are described in any one of Embodiments 1 to 2, further, the switching transistor and switching transistor All use IGBT switches with the gates floating.

[0070] Example 4:

[0071] The all-solid-state parameter adjustable energy recovery excitation source has the main technical contents described in any one of Examples 1 to 3. Furthermore, the working process of the all-solid-state parameter adjustable energy recovery excitation source includes a charging stage, a discharging stage, a commutation stage, and a freewheeling stage.

[0072] Example 5:

[0073] The all-solid-state parameter-adjustable energy recovery excitation source, the main technical contents of which are described in any one of Embodiments 1 to 4, further, when the all-solid-state parameter-adjustable energy recovery excitation source is operating in the charging phase, the switching transistor... In the off state, the switching transistor On, DC power supply Energy through resistance ,diode ,diode ,diode Switching transistor Stored in energy storage capacitor middle.

[0074] Example 6:

[0075] The all-solid-state parameter-adjustable energy recovery excitation source, the main technical contents of which are described in any one of Examples 1 to 5, further, when the all-solid-state parameter-adjustable energy recovery excitation source is operating in the discharge stage, the switching transistor... and switching transistor On, energy storage capacitor The energy stored in it is transmitted through the switching transistor. and switching transistor Release to load resistor and load inductance superior.

[0076] Example 7:

[0077] The all-solid-state parameter-adjustable energy recovery excitation source, the main technical contents of which are described in any one of Examples 1 to 6, further, when the all-solid-state parameter-adjustable energy recovery excitation source is operating in the commutation stage, the switching transistor... and switching transistor Both are in the off state, load inductance The energy stored in it is transmitted through diodes ,diode Recovered into energy storage capacitors middle.

[0078] Example 8:

[0079] The all-solid-state parameter-adjustable energy recovery excitation source, the main technical contents of which are described in any one of Examples 1 to 7, further, when the all-solid-state parameter-adjustable energy recovery excitation source is operating in the freewheeling phase, the switching transistor... In the off state, the switching transistor On, load inductance The residual current in the circuit passes through the switching transistor. ,diode To continue streaming.

[0080] Example 9:

[0081] The fully solid-state parameter adjustable energy recovery excitation source, the main technical contents of which are described in any one of Examples 1 to 8, further wherein the parameters of the pulse current include current amplitude, pulse frequency and pulse width.

[0082] The pulse current has an amplitude range of 0-2500 A, a pulse frequency of 0-10 Hz, and a pulse width of 0-200 μs.

[0083] Example 10:

[0084] The all-solid-state parameter-adjustable energy recovery excitation source, the main technical contents of which are described in any one of Examples 1 to 9, further wherein the parameters of the pulse current are controlled by adjusting the switching transistor. Trigger delay, switching transistor On-time and energy storage capacitor The voltage at both ends is adjusted.

[0085] The switching transistor The trigger delay and the duration of the falling edge of the pulse current are positively correlated.

[0086] The switching transistor The conduction time is positively correlated with the rising edge duration of the pulse current.

[0087] The energy storage capacitor The voltage across the terminals is positively correlated with the amplitude of the pulse current.

[0088] Example 11:

[0089] See Figures 1 to 13 The all-solid-state parameter-adjustable energy recovery excitation source mainly includes the following technical contents:

[0090] Figure 1 shows the topology of the all-solid-state parameter-adjustable energy recovery excitation source proposed in this embodiment. This topology can be divided into three core regions according to their circuit functions: a charging circuit, a main power circuit, and a load circuit. Each region undertakes different functional responsibilities during the operation of the excitation source. The charging circuit (yellow area) mainly includes two choke diodes. , Used to regulate the capacitor charging process. Diode. and This forms a series isolation unit used to block interstage reverse current and prevent circuit components from being damaged by voltage. DC power supply. Through the current-limiting resistor Energy storage capacitor Charging. The main power circuit (blue area) consists of two parts: a discharge unit and a commutation unit. The discharge unit comprises an energy storage capacitor. Main switch and clamping diode Its core function is to rapidly transfer energy to the load. The converter unit consists of a converter switch. With diode Composition, including the converter switch Maintain the normally open state. The inductive load (red area) is represented by inductance and resistance, used to reflect the circuit structure of the magnetic field generating unit. This excitation source can be controlled by the commutation switch. The on / off state enables load inductor freewheeling or energy recovery.

[0091] Each module of this multi-level controllable modular excitation source adopts an independent control mode, thereby supporting flexible adjustment of the excitation source's operating status. Figure 2 This demonstrates the different operating states of the excitation source circuit. - The operating sequence of each switch and the variation pattern of the coil current waveform within the time period.

[0092] Based on the operating state of the excitation source, the circuit operation process can be divided into four typical stages: charging stage, discharging stage, commutation stage, and freewheeling stage.

[0093] The specific work process is as follows:

[0094] 1. Charging stage: In - During this period, the circuit status is as follows: Figure 3 As shown.

[0095] 2. Discharging phase: After the charging process is completed, the main switch... When the circuit is closed, the system enters the discharge phase, such as... Figure 4 As shown.

[0096] 3. Commutation stage: When the pulse current rises to... At that time, control the discharge switch All switches are disconnected, at which point the discharge phase ends. If the converter switches at each stage are disconnected during this process... and If synchronous disconnection is achieved, the circuit will switch to energy recovery mode. Figure 2 (a) - During this period, the coil energy will pass through the diode. Unidirectional transfer to each stage of capacitor like Figure 5 As shown, this enables coil energy recovery.

[0097] Meanwhile, due to the power feeding diode On, commutator switch The voltage difference between the two ends passes through Stabilize to Therefore, the power feed diode The introduction of this technology ensures smooth transitions between circuit states and also provides a switching mechanism. It provides a key guarantee for the safe and stable operation of [the system / system].

[0098] 4. Freewheeling Phase: When the discharge phase ends, if the converter switch... If the circuit remains closed, it will switch to the inductor freewheeling phase, which corresponds to... Figure 2 (b) - During this period, the load coil current flows through... and Forming a freewheeling loop, such as Figure 6 As shown.

[0099] In summary, under the premise of constant load inductance, various parameters of the output pulse current can be precisely controlled by adjusting the trigger delay and conduction time of each main switch and setting differentiated capacitor voltages.

[0100] Example 12:

[0101] See Figures 1 to 13 The all-solid-state parameter-adjustable energy recovery excitation source mainly includes the following technical contents:

[0102] To verify the feasibility and innovation of this embodiment, a three-stage discharge module was used for output characteristic testing. To achieve a compact design, the core components of the discharge module and energy feedback circuit were integrated onto the PCB.

[0103] A custom-designed multi-layer solenoid coil with an inner diameter of 10mm was used, employing a 3-layer structure and a total winding of 3×15 turns. It was hand-wound using 1mm diameter polyesterimide enameled copper wire, with a measured inductance of 35.5μH and internal resistance of 49mΩ, meeting the magnetic field output requirements of the target scenario. The capacitance and withstand voltage of the discharge capacitor were determined based on the coil inductance and output parameters. The design goal was to achieve an adjustable coil current rise time within 100μs and a maximum discharge voltage exceeding 1kV, meeting the requirements of transcranial magnetic stimulation parameters and providing parameter space for magnetic perforation applications. The calculated capacitance value for each stage was at least 342.5μF, and the total capacitance for the three stages in series was at least 114.2μF. This modular excitation source allows for voltage imbalance between modules, thus eliminating the need for strictly uniform capacitance values. To verify this characteristic, pulse capacitors with a withstand voltage of 1kV were custom-designed for the first two stages (600μF) and the third stage (1000μF).

[0104] To effectively charge the capacitor, a high-voltage adjustable power supply with a maximum voltage of 1kV and a maximum output power of 1kW was selected as the charging power supply, and a 1kΩ current-limiting resistor was provided to protect the power supply. Charging diode. and It can prevent the switch from being broken down by interstage voltage and suppress the impact of unbalanced loop current on active devices; based on the module's withstand voltage, a diode with a withstand voltage of 1200V is selected to achieve reliable protection.

[0105] To suppress the influence of parasitic parameters on the switches, parasitic inductance is reduced by increasing PCB trace width and shortening paths. The measured series parasitic inductance of the discharge switch circuits in each module is approximately 0.2 μH. To reduce overvoltage surges caused by parasitic inductance during switch turn-off, an RCD buffer circuit (topology as shown) is connected in parallel across both the discharge switch and the converter switch. Figure 7 Buffer capacitor and The primary function is to absorb commutation energy during switching operations (within 1μs) to reduce the switch load and suppress overvoltage spikes. Based on the switch's withstand voltage, the overvoltage spikes need to be limited to below 1200V and the corresponding energy absorbed; therefore, a 1200V withstand voltage, 3μF polypropylene film capacitor is selected as the primary capacitor. and A 5Ω metal film resistor was selected as the... and This resistance value allows the buffer capacitor to quickly release energy during switch-on. Buffer diode. and A parallel diode is connected across the buffer resistor to provide a path for the capacitor to absorb overshoot energy. Actual measurements show that the maximum current overshoot during switch operation exceeds 1000A; therefore, two parallel diodes are used to provide overcurrent bypass. All buffer components are integrated on the PCB and positioned close to the switch pins to minimize the impact of lead inductance on the buffering effect, ensuring stable switch operation and a smooth installation. Figure 8 As shown, it includes: a buffer capacitor 13, an IGBT drive circuit 14, a buffer diode 15, and a buffer resistor 16.

[0106] Ultimately, such as Figure 9 The three-level controllable modular excitation source platform shown includes a DC power supply 1, a current sensor 2, a load coil 3, a voltage probe 4, an oscilloscope 5, an FPGA control system 6, a buffer circuit 7, a discharge capacitor 8, an IGBT switch 9, a current limiting resistor 10, a three-level controllable modular pulse magnetic field generator 11, and a switching power supply 12.

[0107] One of the features of this excitation source is its ability to flexibly adjust the current pulse width and amplitude. The current pulse width is determined by the switching on / off time, i.e., the discharge time. It can be determined that the current amplitude can be controlled by adjusting the charging voltage when the discharge time is fixed. Adjustments are made. When all modules of the excitation source operate synchronously and output triangular wave pulses, Figure 10 The on-time of the switch is shown separately. =50μs, voltage of each discharge capacitor The coil pulse current and voltage waveforms increase sequentially. Figure 11 Discharge voltage of each capacitor At 400V, different switch conduction times The corresponding coil current and voltage waveforms.

[0108] The core feature of this modular excitation source lies in the strong correlation between its output flexibility and the number of discharge modules. That is, by adjusting the number of discharge modules involved in operation, the output parameters of the excitation source can be flexibly controlled. This characteristic is also a key advantage of modular design compared to traditional integrated excitation sources, providing a convenient adjustment method to adapt to the magnetic field output requirements of different application scenarios. To further describe the current control capability of the proposed topology, tests were conducted on the constructed three-stage modular excitation source experimental platform. Through the coordinated operation timing of each stage of the switches, this excitation source can output multi-stage varied stepped pulse waves to the load coil. Figure 12 The timing sequence of each switch corresponding to the two types of stepped waves is shown. Figure 13 The stepped pulse current and its voltage waveform output from the excitation source to the coil are shown.

[0109] In summary, this embodiment proposes a fully solid-state parameter-adjustable energy recovery excitation source. Its working principle and output performance were systematically analyzed, and a three-stage modular excitation source experimental platform was built through core component selection and parameter design. Based on measured data of capacitor voltage and coil current during pulse output, the system's energy efficiency was quantitatively calculated. The results show that within a switching conduction time range of 25 μs to 100 μs, the system can flexibly modulate various waveforms such as triangular waves and exponential waves. Furthermore, the coil current control capability of the three-stage excitation source physical platform was tested, successfully outputting a stepped pulse waveform with multi-level current change rate and voltage characteristics. The test results verify that this excitation source can achieve flexible control of the output coil pulse current across the entire frequency band by controlling the timing of the control circuit modules, thus providing technical support for research on diverse pulsed electromagnetic biological effects.

Claims

1. A fully solid-state parameter-adjustable energy recovery excitation source, characterized in that, include: Charging circuit, main power circuit, load circuit; The charging circuit is used to store the energy from the external power source into the energy storage capacitor of the main power circuit. The main power circuit is used to release the energy stored in the charging circuit to the load circuit and output pulse current on the load inductor of the load circuit, thereby generating a magnetic field. The main power circuit is used to provide a freewheeling path for the residual current in the load circuit. The main power circuit is used to recover the energy stored in the load circuit into the energy storage capacitor.

2. The all-solid-state parameter-adjustable energy recovery excitation source according to claim 1, characterized in that, The circuit topology of the all-solid-state parameter-tunable energy recovery excitation source is shown below: DC power supply The negative terminal is grounded, and the positive terminal is connected in series with a resistor. Connected to diode The anode; diode The cathode is connected to the diode. The anode is k, which is the index of the energy storage capacitor, and k = 1, 2, ..., n-1, where n is the total number of energy storage capacitors; diode The cathode is connected to the diode. anode, diode Cathode series energy storage capacitor Connected to diode The anode is denoted by s, where s is the index of the energy storage capacitor, and s = 1, 2, ..., n; diode The cathode is connected to the diode. cathode, diode The anode is connected to the switching transistor. collector, switching transistor The emitter is connected to the diode. The anode; diode The cathode is connected to the switching transistor. collector, switching transistor The emitter is connected to the diode. The cathode; diode The cathode is connected to the switching transistor. The collector; diode The cathode is grounded; diode The anodes are connected in series with load resistors. and load inductance Grounded afterward.

3. The all-solid-state parameter-adjustable energy recovery excitation source according to claim 2, characterized in that, The switching transistor and switching transistor All use IGBT switches with the gates floating.

4. The all-solid-state parameter-adjustable energy recovery excitation source according to claim 2, characterized in that, The working process of the all-solid-state parameter adjustable energy recovery excitation source includes a charging stage, a discharging stage, a commutation stage, and a freewheeling stage.

5. The all-solid-state parameter-adjustable energy recovery excitation source according to claim 4, characterized in that, When the all-solid-state parameter-tunable energy recovery excitation source is operating in the charging phase, the switching transistor... In the off state, the switching transistor On, DC power supply Energy through resistance ,diode ,diode ,diode Switching transistor Stored in energy storage capacitor middle.

6. The all-solid-state parameter-adjustable energy recovery excitation source according to claim 4, characterized in that, When the all-solid-state parameter-tunable energy recovery excitation source is operating in the discharge phase, the switching transistor... and switching transistor On, energy storage capacitor The energy stored in it is transmitted through the switching transistor. and switching transistor Release to load resistor and load inductance superior.

7. The all-solid-state parameter-adjustable energy recovery excitation source according to claim 4, characterized in that, When the all-solid-state parameter-tunable energy recovery excitation source operates in the commutation phase, the switching transistor... and switching transistor Both are in the off state, load inductance The energy stored in it is transmitted through diodes ,diode Recovered into energy storage capacitors middle.

8. The all-solid-state parameter-adjustable energy recovery excitation source according to claim 4, characterized in that, When the all-solid-state parameter-tunable energy recovery excitation source operates in the freewheeling phase, the switching transistor... In the off state, the switching transistor On, load inductance The residual current in the circuit passes through the switching transistor. ,diode To continue streaming.

9. The all-solid-state parameter-adjustable energy recovery excitation source according to claim 1, characterized in that, The parameters of the pulse current include current amplitude, pulse frequency, and pulse width; The pulse current has an amplitude range of 0-2500 A, a pulse frequency of 0-10 Hz, and a pulse width of 0-200 μs.

10. The all-solid-state parameter-adjustable energy recovery excitation source according to any one of claims 2 or 9, characterized in that, The parameters of the pulse current are controlled by adjusting the switching transistor. Trigger delay, switching transistor On-time and energy storage capacitor The voltage at both ends is adjusted; The switching transistor The trigger delay and the duration of the falling edge of the pulse current are positively correlated; The switching transistor The conduction time is positively correlated with the rise time of the pulse current; The energy storage capacitor The voltage across the terminals is positively correlated with the amplitude of the pulse current.

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