A launch stage number switchable electromagnetic cannon system

Abstract

This invention proposes a switchable-stage electromagnetic railgun system, comprising: a charging circuit module that converts low-voltage DC power into high-voltage DC power to charge an energy storage module; an energy storage module including primary and secondary energy storage capacitors; a discharging module that releases excess energy; an energy conversion and regulation module that realizes energy conversion between the primary and secondary energy storage capacitors; a launch execution module that utilizes the energy in the energy storage module to achieve the launch function of the electromagnetic railgun; and a control and monitoring module that, in conjunction with an MCU (microcontroller unit), realizes the switching between different system states. This invention can control the energy of each stage of the launch circuit, has a wider adjustment range and higher precision, and at the same time, fully utilizes the secondary energy storage capacitors in single-stage launch, improving the charging and discharging speed.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic railgun technology with switchable firing stages, and more specifically, to an electromagnetic railgun system with switchable firing stages. Background Technology

[0002] As military and technological applications increasingly demand higher efficiency and precision from weapon systems, the limitations of traditional artillery have become more apparent, leading to the development of electromagnetic railguns. Compared to traditional artillery, electromagnetic railguns offer advantages such as lower cost, higher projectile velocity, lower noise, and better concealment, making them popular with various countries.

[0003] Existing electromagnetic railgun systems suffer from the following problems: 1. Many railgun designs use non-adjustable voltage in their energy storage capacitors, resulting in an inability to adjust the projectile's velocity. Some railguns lack an upper limit on the charging voltage, potentially leading to circuit damage due to excessively high charging voltage. 2. Single-stage railguns can only use one coil to accelerate the projectile, limiting their acceleration capability. Multi-stage railguns exhibit lower accuracy and efficiency when facing close-range targets. 3. Traditional adjustable-voltage railgun charging circuits often employ resistive discharge when the actual voltage exceeds the set voltage. This discharge method converts excess energy into heat on the resistor, causing significant overheating. The discharge speed is also constrained by the system's heat dissipation capabilities. Summary of the Invention

[0004] In view of this, the present invention proposes an electromagnetic gun system with switchable firing stages, aiming to solve the problems of uncontrollable voltage of energy storage capacitors, weak acceleration capability of single-stage electromagnetic guns, low close-range firing accuracy of multi-stage electromagnetic guns, and large energy loss in energy storage capacitor voltage regulation in existing electromagnetic gun technologies.

[0005] In one aspect, the present invention proposes an electromagnetic railgun system with switchable firing stages, comprising:

[0006] The charging circuit module is used to convert low-voltage DC power input into high-voltage DC power through inversion, boost and rectification processes. The charging circuit module adjusts the charging current through phase shift control and related mode operation. The charging circuit module consists of a full-bridge inverter circuit, a current-limiting inductor, a transformer and an uncontrolled rectifier circuit.

[0007] An energy storage module includes a primary energy storage capacitor and a secondary energy storage capacitor. The energy storage module is used to store the energy required to launch the electromagnetic gun. When the two-stage launch occurs, it provides energy to the primary and secondary launch coils respectively. When the single-stage launch occurs, the primary energy storage capacitor supplies energy to the primary launch coil. The secondary energy storage capacitor acts as an energy buffer for the primary energy storage capacitor. Both the primary and secondary energy storage capacitors are electrolytic capacitors.

[0008] The discharge module uses a discharge circuit to discharge the remaining electrical energy in the energy storage capacitor that exceeds the usage threshold. The discharge circuit consists of a MOS transistor and a discharge resistor, and the discharge circuit is connected in parallel with the first-stage energy storage capacitor.

[0009] The energy conversion and regulation module utilizes a bidirectional Buck-Boost converter circuit to adjust the voltages of the first-stage and second-stage energy storage capacitors during two-stage transmission, and assists the first-stage energy storage capacitor in energy management during single-stage transmission. The bidirectional Buck-Boost converter circuit consists of MOSFETs S5 and S6 and an energy storage inductor. The bidirectional Buck-Boost converter circuit is connected between the first-stage and second-stage energy storage capacitors, and achieves bidirectional energy flow between the two energy storage capacitors by controlling the on / off state of the MOSFETs. The bidirectional Buck-Boost converter circuit has four operating modes and uses a pop-pop control method to control the current of the energy storage inductor.

[0010] The transmission execution module consists of a primary transmission circuit and a secondary transmission circuit. Both the primary and secondary transmission circuits include a freewheeling diode, a reverse voltage protection diode, a transmission coil, and a MOSFET. When the MOSFET is turned on, the energy storage capacitor supplies power to the transmission coil. When the MOSFET is turned off, the diode provides freewheeling current to the coil. When the MOSFETs of other stages of the transmission circuit are turned on, the reverse voltage protection diode prevents current backflow.

[0011] The control and monitoring module includes a sampling circuit, a driving circuit, a photoelectric sensor, a communication circuit, and an MCU and its peripheral circuits. The sampling circuit is used to collect various current and voltage signals, the driving circuit is used to drive the MOS transistors in each circuit to turn on and off, the photoelectric sensor is used to detect the position of the projectile, the communication circuit is used to interact with the host computer, and the MCU and its peripheral circuits are used to receive information and output driving signals.

[0012] The charging circuit charges the primary and secondary energy storage capacitors. The sampling circuit monitors the charging current, inductor current, and capacitor voltage in real time and transmits the information to the MCU and its peripheral circuits. In two-stage launch mode, the MCU controls the charging circuit, the discharging circuit, and the bidirectional Buck-Boost converter circuit to follow the given voltages of the primary and secondary energy storage capacitors. In single-stage launch mode, the MCU controls the operation of each circuit and stabilizes the voltage of the primary energy storage capacitor based on the voltage of the primary energy storage capacitor and the energy state of the secondary energy storage capacitor. During launch, the photoelectric sensor detects the projectile position and sends it to the MCU, which controls the switching on and off of the MOSFETs in the primary and secondary launch circuits.

[0013] Furthermore, the full-bridge inverter circuit converts DC to AC by controlling the on and off states of four MOSFETs. During the inversion process, the full-bridge inverter circuit uses phase-shift control to adjust the charging current. The full-bridge inverter circuit has six operating modes. In mode 1, when MOSFETs S1 and S4 are on and MOSFETs S2 and S3 are off, the current in the current-limiting inductor flows from MOSFET S4 to MOSFET S1. The induced voltage on the primary winding of the transformer is negative, and the voltage across the current-limiting inductor is Uin + Uc1 / N. In mode 2, the MOSFET switching states are the same as in mode 1. The current in the current-limiting inductor drops to zero, then reverses direction and slowly increases. At this time, the induced voltage on the primary winding of the transformer is positive, and the voltage across the current-limiting inductor is Ui. In mode 3, MOSFETs S2 and S4 are turned on, while MOSFETs S1 and S3 are turned off. The induced voltage in the primary winding of the transformer remains positive, and the voltage across the current-limiting inductor is -Uc1 / N. The current decreases. In mode 4, MOSFETs S2 and S3 are turned on, while MOSFETs S1 and S4 are turned off. The induced voltage in the primary winding of the transformer is positive, and the voltage across the current-limiting inductor is -Ui n-Uc1 / N. The current direction remains unchanged, but its magnitude decreases rapidly. In mode 5, the MOSFET switching state is the same as in mode 4. The current in the current-limiting inductor drops to zero, then reverses direction and slowly increases. The induced voltage in the primary winding of the transformer is negative, and the voltage across the current-limiting inductor is -Ui. In mode 6, MOSFETs S1 and S3 are turned on, while MOSFETs S2 and S4 are turned off. At this time, the induced voltage of the primary winding of the transformer is still negative, the voltage across the current-limiting inductor is Uc1 / N, and the current decreases. When the phase shift angle increases, the inverter operates in modes 3 and 6 for a longer period, the current change of the current-limiting inductor slows down, and the charging current decreases. The current-limiting inductor is connected in series between the full-bridge inverter circuit and the transformer. The transformer boosts the inverted AC power.

[0014] Furthermore, in the two-stage launch operation, the primary energy storage capacitor and the secondary energy storage capacitor store the energy required by the primary and secondary launch coils, respectively. A 450V 470uF capacitor is selected as the primary energy storage capacitor, and a 450V 330uF capacitor is selected as the secondary energy storage capacitor. When preparing for two-stage launch, the charging circuit charges the primary and secondary energy storage capacitors respectively. During launch, the primary launch coil first uses the energy stored in the primary energy storage capacitor to initially accelerate the projectile. When the projectile leaves the area of ​​the primary launch coil, the MOSFET in the primary launch circuit is turned off, and the power supply to the primary energy storage capacitor is cut off. When the projectile moves to the position of the secondary launch coil, the secondary energy storage capacitor releases energy. When the projectile leaves the area of ​​the secondary launch coil, the MOSFET in the secondary launch circuit is turned off, and the power supply to the secondary energy storage capacitor is cut off.

[0015] Furthermore, in single-stage transmission operation, the primary energy storage capacitor stores the energy required by the primary transmission coil, and the secondary energy storage capacitor acts as an energy buffer for the primary energy storage capacitor. When the voltage of the primary energy storage capacitor is higher than the set reference voltage and the secondary energy storage capacitor is not fully charged, the primary energy storage capacitor directly discharges to the secondary energy storage capacitor; when the voltage of the primary energy storage capacitor is lower than the set reference voltage and the secondary energy storage capacitor has electrical energy, the secondary energy storage capacitor charges the primary energy storage capacitor.

[0016] Furthermore, the discharge module operates in both a two-stage emission mode and a single-stage emission mode with the secondary energy storage capacitor fully charged. When the energy in the energy storage capacitor exceeds a threshold, the discharge module releases the excess energy. In the two-stage emission mode, when the voltages of both energy storage capacitors are too high, or when one capacitor has a suitable voltage while the other has a high voltage, the discharge circuit is activated to release the excess energy. In the single-stage emission mode, when the voltage of the primary energy storage capacitor is too high and the energy stored in the secondary energy storage capacitor reaches its upper limit, the discharge circuit is activated to release the excess energy in the primary energy storage capacitor. When the discharge circuit is working, the MOSFET is turned on, and the excess energy in the primary energy storage capacitor forms a circuit through the discharge resistor, so that the electrical energy is converted into heat energy based on resistance.

[0017] Furthermore, the source of MOSFET S5 is connected to the drain of MOSFET S6, the drain of MOSFET S5 is connected to the positive terminal of the first-stage energy storage capacitor, and the source of MOSFET S6 is connected to the negative terminal of the second-stage energy storage capacitor. One end of the energy storage inductor is connected to the source of MOSFET S5, and the other end is connected to the negative terminal of the first-stage energy storage capacitor and the positive terminal of the second-stage energy storage capacitor. The bidirectional Buck-Boost converter circuit has two operating modes in each of the two energy flow directions, for a total of four operating modes. In mode 1, MOSFET S5 is turned on, MOSFET S6 is turned off, the current in the energy storage inductor increases, and energy is transferred from the first-stage energy storage capacitor to the energy storage inductor. In mode 2, both MOSFET S5 and MOSFET S6 are turned off, and the current in the energy storage inductor flows through the second-stage energy storage capacitor and the MOSFET S6. In mode 3, MOSFET S6 is turned on and MOSFET S5 is turned off. The current in the energy storage inductor increases, the voltage rises, and energy is transferred from the energy storage inductor to the energy storage capacitor. In mode 4, both MOSFETs S5 and S6 are turned off. The current in the energy storage inductor flows through the primary energy storage capacitor and the body diode of MOSFET S5, allowing freewheeling. The primary energy storage capacitor is charged, the voltage rises, and energy is transferred from the energy storage inductor to the secondary energy storage capacitor. The circuit is controlled by a "bang-bang" control method: when the current in the energy storage inductor exceeds a set maximum value, the corresponding switch is turned off; when the current in the energy storage inductor is less than a set minimum value, the corresponding switch is turned on.

[0018] Furthermore, when the MOSFET is turned on, the energy storage capacitor supplies power to the transmitting coil, and current flows through the transmitting coil. In the first-stage transmitting circuit, when the MOSFET is turned on, the first-stage energy storage capacitor provides energy to the first-stage transmitting coil. When the MOSFET is turned off, the current in the transmitting coil is freewheeled through the freewheeling diode and the reverse voltage protection diode. The freewheeling diode provides a freewheeling path for the coil current. When the MOSFETs in other stages of the transmitting circuit are turned on, the reverse voltage protection diode prevents current backflow.

[0019] Furthermore, the sampling circuit is used to collect the average current of the charging circuit, the instantaneous inductor current of the bidirectional Buck-Boost circuit, and the voltages on the first-stage and second-stage energy storage capacitors. The sampling circuit also sends the sampling signal to the MCU. The driving circuit converts the signal waveform output by the MCU into a driving waveform to drive the MOSFETs in each circuit to turn on or off. The photoelectric sensor is placed on both sides of the firing coil on the barrel to detect the position of the projectile within the barrel. The MCU controls the on / off state of the MOSFETs in the multi-stage firing circuit based on the projectile's position. The communication circuit is used to interact with the host computer and observe... The MCU receives various information collected by the sampling circuit and given signals provided by the host computer to determine its operating state. Based on a preset algorithm and control strategy, it outputs corresponding drive signals to control the operation of each circuit module. In two-stage transmission mode, the MCU controls the operation of the charging circuit, the discharging circuit, and the bidirectional Buck-Boost converter circuit based on the voltages on the primary and secondary energy storage capacitors. In single-stage transmission mode, the MCU controls the operation of each circuit based on the voltage of the primary energy storage capacitor and the energy state of the secondary energy storage capacitor.

[0020] Furthermore, the charging circuit sequentially inverts, boosts, and rectifies the DC input to charge the primary energy storage capacitor and the secondary energy storage capacitor. During the charging process, the sampling circuit monitors the charging current, inductor current, and capacitor voltage in real time and transmits this information to the MCU and its peripheral circuits. The MCU controls the magnitude of the charging current through phase-shift modulation based on the received information and achieves constant current charging through PI control.

[0021] In two-stage transmit mode, the MCU controls the operation of the charging circuit, the discharging circuit, and the bidirectional Buck-Boost converter circuit based on the voltages on the primary and secondary energy storage capacitors relative to a given value, as collected by the sampling circuit. When one capacitor voltage is higher than the given value and the other capacitor voltage is lower than the given value, both the charging circuit and the discharging circuit are turned off, and energy flows between the two capacitors through the bidirectional Buck-Boost converter circuit. When both capacitor voltages are too high, or one capacitor voltage is appropriate and the other capacitor voltage is too high, the charging circuit is turned off and the discharging circuit is turned on. If the voltage on the secondary energy storage capacitor is too high at this time, the bidirectional Buck-Boost converter circuit is turned on to transfer energy to the primary energy storage capacitor. When both capacitor voltages are lower than the given value, or one capacitor voltage is appropriate and the other capacitor voltage is too high, the charging circuit is turned on and the discharging circuit is turned off. If the voltage on the secondary energy storage capacitor is lower than the given value at this time, the bidirectional Buck-Boost converter circuit is turned on to transfer energy from the primary energy storage capacitor to the secondary energy storage capacitor. When both capacitor voltages are appropriate, all MOSFETs remain off.

[0022] In single-stage transmit mode, the MCU controls the operation of each circuit based on the energy states of the primary and secondary energy storage capacitors. When the voltage of the primary energy storage capacitor is too high and the energy storage in the secondary energy storage capacitor has not reached its upper limit, the primary energy storage capacitor discharges to the secondary energy storage capacitor through the bidirectional Buck-Boost converter circuit. When the voltage of the primary energy storage capacitor is too high and the energy storage in the secondary energy storage capacitor has reached its upper limit, the discharge circuit is activated to release the excess energy in the primary energy storage capacitor. When the voltage of the primary energy storage capacitor is too low and there is energy stored in the secondary energy storage capacitor, the secondary energy storage capacitor discharges to the primary energy storage capacitor through the bidirectional Buck-Boost converter circuit. When the voltage of the primary energy storage capacitor is too low and the energy in the secondary energy storage capacitor is insufficient, the charging circuit is activated to charge the primary energy storage capacitor. When the voltage of the primary energy storage capacitor is appropriate, all MOSFETs remain off.

[0023] When preparing to fire, the photoelectric sensor detects the projectile's position in the barrel and sends the position information to the MCU. Based on the projectile's position information, the MCU controls the switching on and off of the MOSFETs in the primary and secondary firing circuits. When the host computer sends a command to the MCU, the MCU controls the MOSFETs in the primary firing circuit to turn on, and the primary energy storage capacitor supplies power to the primary firing coil. When the projectile leaves the area of ​​the primary firing coil, the MOSFETs in the primary firing circuit turn off, and the primary energy storage capacitor cuts off its power supply. When the projectile moves to the position of the secondary firing coil and is in the two-stage firing operation state, the MCU controls the MOSFETs in the secondary firing circuit to turn on, and the secondary energy storage capacitor supplies power to the secondary firing coil. When the projectile leaves the area of ​​the secondary firing coil, the MOSFETs in the secondary firing circuit turn off, and the secondary energy storage capacitor cuts off its power supply.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] 1. This design can switch between single-stage and two-stage launch, which improves the accuracy of close-range launch compared with traditional two-stage launch electromagnetic guns, and increases the maximum launch distance of electromagnetic guns compared with traditional single-stage launch electromagnetic guns.

[0026] 2. In this design, the secondary energy storage capacitor is not directly connected to the primary energy storage capacitor and the charging circuit, but is connected to it through a bidirectional Buck-Boost circuit. Therefore, when the system is operating in two-stage firing mode, the voltage on the primary and secondary energy storage capacitors can be controlled separately, thereby improving the accuracy of the electromagnetic gun firing.

[0027] 3. In the single-stage transmission mode, this design uses the secondary energy storage capacitor as an energy buffer for the primary energy storage capacitor, which can improve the speed of voltage regulation of the primary energy storage capacitor, reduce energy loss during voltage regulation, and improve system efficiency. Attached Figure Description

[0028] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0029] Figure 1 This is a functional block diagram of an electromagnetic railgun system with switchable firing stages according to an embodiment of the present invention;

[0030] Figure 2 This is a general design block diagram of an electromagnetic railgun system with switchable firing stages according to an embodiment of the present invention;

[0031] Figure 3 This is a circuit diagram of an electromagnetic gun system with switchable firing stages according to an embodiment of the present invention;

[0032] Figure 4 This is a modal operation diagram of the charging circuit in an embodiment of the present invention during half a cycle.

[0033] Figure 5 This is a modal diagram of the bidirectional Buck-Boost circuit according to an embodiment of the present invention;

[0034] Figure 6 This is a schematic diagram of the circuit in different modes and the direction of transition in an embodiment of the present invention. Detailed Implementation

[0035] Exemplary embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the invention to those skilled in the art. It should be noted that, without conflict, the embodiments and features described herein can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0036] Reference Figure 1-6 As shown in some embodiments of this application, an electromagnetic railgun system with switchable firing stages includes:

[0037] The charging circuit module is used to convert low-voltage DC power input into DC power through inversion, boost and rectification in sequence. The charging circuit module regulates the charging current through phase shift control and related mode operation. The charging circuit module consists of a full-bridge inverter circuit, a current-limiting inductor, a transformer and an uncontrolled rectifier circuit.

[0038] The energy storage module is used to store the energy required to launch the electromagnetic gun. When the two-stage launch is performed, it provides energy to the first-stage and second-stage launch coils respectively. When the single-stage launch is performed, the first-stage energy storage capacitor supplies energy to the first-stage launch coil, and the second-stage energy storage capacitor acts as an energy buffer for the first-stage energy storage capacitor. Both the first-stage and second-stage energy storage capacitors are electrolytic capacitors.

[0039] The discharge module uses a discharge circuit to release excess energy from the energy storage capacitor. The discharge circuit consists of a MOSFET and a discharge resistor, and is connected in parallel with the first-stage energy storage capacitor.

[0040] The energy conversion and regulation module utilizes a bidirectional Buck-Boost converter circuit to regulate the voltages of the primary and secondary energy storage capacitors during two-stage transmission, and assists the primary energy storage capacitor in energy management during single-stage transmission. The bidirectional Buck-Boost converter circuit consists of MOSFETs S5 and S6 and an energy storage inductor. The bidirectional Buck-Boost converter circuit is connected between the primary and secondary energy storage capacitors and realizes bidirectional energy flow between the two energy storage capacitors by controlling the on and off states of the MOSFETs. The bidirectional Buck-Boost converter circuit has four operating modes and uses a pop-pop control method to control the current of the energy storage inductor.

[0041] The transmission execution module consists of a primary transmission circuit and a secondary transmission circuit. The primary and secondary transmission circuits have the same structure, both including a freewheeling diode, a reverse voltage protection diode, a transmission coil, and a MOSFET. When the MOSFET is turned on, the energy storage capacitor supplies power to the transmission coil. When the MOSFET is turned off, the diode provides freewheeling current to the coil. When the MOSFETs of other stages of the transmission circuit are turned on, the reverse voltage protection diode prevents current backflow.

[0042] The control and monitoring module includes a sampling circuit, a drive circuit, a photoelectric sensor, a communication circuit, and an MCU and its peripheral circuits. The sampling circuit is used to collect various current and voltage signals, the drive circuit is used to drive the MOS transistors in each circuit to turn on and off, the photoelectric sensor is used to detect the position of the projectile, the communication circuit is used to interact with the host computer, and the MCU and its peripheral circuits are used to receive information and output drive signals.

[0043] Specifically, the full-bridge inverter circuit is the key component in converting DC input to AC. It achieves the DC-to-AC inversion process by controlling the on / off state of four MOSFETs (S1-S4). During the inversion process, phase-shift control is used to precisely regulate the charging current. It has six operating modes. In mode 1, when MOSFETs S1 and S4 are on and S2 and S3 are off, the current in inductor L1 flows from S4 to S1, the induced voltage on the primary winding of the transformer is negative, and the voltage across inductor L1 is Uin + Uc1 / N. At this time, the current decreases rapidly. In mode 2, the MOSFET switching state is the same as in mode 1. The current in the current-limiting inductor drops to zero, then reverses and slowly increases. At this time, the induced voltage on the primary winding of the transformer is positive, and the voltage across the current-limiting inductor is Ui. In mode 3, MOSFETs S2 and S4 are turned on, while MOSFETs S1 and S3 are turned off. The induced voltage in the primary winding of the transformer remains positive, and the voltage across the current-limiting inductor is -Uc1 / N. The current decreases. In mode 4, MOSFETs S2 and S3 are turned on, while MOSFETs S1 and S4 are turned off. The induced voltage in the primary winding of the transformer is positive, and the voltage across the current-limiting inductor is -Ui / n-Uc1 / N. The current direction remains unchanged, but its magnitude decreases rapidly. In mode 5, the MOSFET switching state is the same as in mode 4. The current in the current-limiting inductor drops to zero, then reverses direction and slowly increases. The induced voltage in the primary winding of the transformer is negative, and the voltage across the current-limiting inductor is -Ui / n-Uc1 / N. In mode 6, MOSFETs S1 and S3 are turned on, while MOSFETs S2 and S4 are turned off. At this time, the induced voltage in the primary winding of the transformer is still negative, and the voltage across the current-limiting inductor is Uc1 / N, resulting in a decrease in current. As the phase shift angle changes, the inverter's operating time in different modes changes, thus affecting the rate of change of the inductor current and consequently controlling the charging current. When the phase shift angle increases, the inverter operates for longer periods in modes 3 and 6, the inductor current change slows down, and the charging current decreases.

[0044] The current-limiting inductor L1 is connected in series between the full-bridge inverter circuit and the transformer. Its main function is to limit the magnitude of the primary current.

[0045] The transformer is responsible for boosting the inverter-generated alternating current to obtain a higher voltage, providing a sufficiently high voltage for charging the subsequent energy storage capacitors. It utilizes the principle of electromagnetic induction, increasing the voltage through the turns ratio of the primary and secondary windings. The uncontrolled rectifier circuit then converts the high-voltage alternating current output from the transformer into direct current, ultimately achieving DC charging of the energy storage capacitors.

[0046] Understandably, the charging circuit module can systematically process the DC input through inversion, boosting, and rectification, efficiently converting it into DC power suitable for energy storage. Furthermore, it uses phase-shifting modulation under PI control to regulate the charging current and ensure current stability.

[0047] Specifically, in the two-stage launch operation, the primary energy storage capacitor C1 and the secondary energy storage capacitor C2 store the energy required by the primary and secondary launch coils, respectively. For example, during launch, the primary launch coil first uses the energy stored in C1 to initially accelerate the projectile. When the projectile leaves the primary launch coil area, the MOSFET in the primary launch circuit is turned off, and the primary energy storage capacitor is disconnected from the power supply. When the projectile reaches the secondary launch coil position, C2 releases energy to provide further acceleration. When the projectile leaves the secondary launch coil area, the MOSFET in the secondary launch circuit is turned off, and the secondary energy storage capacitor is disconnected from the power supply, thus achieving a two-stage acceleration effect and improving the projectile's launch speed and range. Considering the short time the projectile spends in the secondary acceleration coil, the capacity of the secondary energy storage capacitor C2 is relatively small. Here, a 450V 470uF capacitor is selected as the primary energy storage capacitor C1, and a 450V 330uF capacitor is selected as the secondary energy storage capacitor C2. When the system is ready for two-stage launch, the charging circuit charges both capacitors to store sufficient energy.

[0048] When the system is in single-stage transmission mode, the primary energy storage capacitor C1 stores the energy required by the first-stage transmitting coil. At this time, the secondary energy storage capacitor C2 acts as an energy buffer for the primary energy storage capacitor C1. When the voltage of the primary energy storage capacitor C1 is higher than the set reference voltage and the secondary energy storage capacitor C2 is not fully charged, the primary energy storage capacitor C1 directly discharges to the secondary energy storage capacitor C2. When the voltage of the primary energy storage capacitor C1 is lower than the set reference voltage and the secondary energy storage capacitor C2 contains energy, the secondary energy storage capacitor C2 charges the primary energy storage capacitor C1. This energy buffering mechanism effectively improves the speed of voltage regulation of the primary energy storage capacitor C1 while reducing energy loss during voltage regulation, thus improving system efficiency.

[0049] Specifically, the discharge module only operates in two-stage emission mode or single-stage emission mode when the energy buffer (secondary energy storage capacitor C2) is fully charged. In these cases, when the energy in the energy storage capacitor exceeds the system requirements or a set upper limit, the discharge module needs to release the excess energy to prevent overvoltage damage to the capacitor or impact on system performance. For example, in two-stage emission mode, if the voltage of both energy storage capacitors is too high, or if one capacitor has a suitable voltage while the other has a high voltage, the discharge circuit will activate to release the excess energy. In single-stage emission mode, when the voltage of capacitor C1 is too high and the energy stored in C2 has reached its upper limit, the discharge circuit will also activate to release the excess energy in C1.

[0050] When the discharge circuit is working, the MOSFET is turned on. At this time, the excess energy in the energy storage capacitor C1 forms a circuit through the discharge resistor, and the electrical energy is converted into heat energy and dissipated, thus realizing energy release. This method can effectively control the voltage of the energy storage capacitor.

[0051] Specifically, the energy conversion and regulation module consists of MOSFETs S5 and S6 and inductor L2. The source of MOSFET S5 is connected to the drain of MOSFET S6, and the drain of S5 is connected to the positive terminal of energy storage capacitor C1. The source of S6 is connected to the negative terminal of energy storage capacitor C2. One end of inductor L2 is connected to the source of S5, and the other end is connected to the negative terminal of C1 and the positive terminal of C2. This topology allows energy to flow between the two capacitors, laying the foundation for multiple functions. This topology has two operating modes in each of the two energy flow directions, for a total of four operating modes. In mode 1, MOSFET S5 is turned on and S6 is turned off. At this time, the current in inductor L2 increases, and energy is transferred from energy storage capacitor C1 to inductor L2. In mode 2, both MOSFETs S5 and S6 are off. The current in inductor L2 freewheels through the energy storage capacitor C2 and the body diode of MOSFET S6, charging C2, increasing the voltage, and transferring energy from inductor L2 to C2. Switching between modes 1 and 2 allows for energy transfer from C1 to C2. Similarly, in mode 3, MOSFET S6 is on and S5 is off. The current in inductor L2 increases, but its direction is opposite to that in mode 1, and energy transfers from the energy storage capacitor C2 to inductor L2. In mode 4, both MOSFETs S5 and S6 are off. The current in inductor L2 freewheels through the energy storage capacitor C1 and the body diode of MOSFET S5, charging C1, increasing the voltage, and transferring energy from inductor L2 to C2. Switching between modes 3 and 4 allows for energy transfer from C2 to C1.

[0052] Since both sides of this circuit are capacitors, their voltage changes with the energy stored within them. Therefore, traditional duty cycle methods are not suitable for circuit control. To limit the charging current, a "bang-bang" control method is used to regulate the current flowing through inductor L2. Specifically, when the current exceeds the set maximum current value, the corresponding switch is turned off; conversely, when the current is less than the set minimum current value, the corresponding switch is turned off. This control method effectively protects the circuit components and ensures the stability and safety of the energy conversion process.

[0053] Understandably, the energy conversion and regulation module, with its bidirectional Buck-Boost converter circuit consisting of MOSFET S5, MOSFET S6 and energy storage inductor, is connected between the first and second stage energy storage capacitors. By controlling the switching on and off of the MOSFETs, it achieves bidirectional energy flow. During two-stage transmission, it precisely regulates the voltage of the two capacitors. During single-stage transmission, it effectively assists the first stage energy storage capacitor in managing energy and uses a pop-pop control method to limit the magnitude of the conversion current.

[0054] Specifically, when the MOSFET in the launch execution module is turned on, the energy storage capacitor supplies power to the launch coil, and current flows through the launch coil. According to the law of electromagnetic induction, the energized coil generates a magnetic field, which exerts a Lorentz force on the projectile located within it, thereby accelerating the projectile. During this process, the coil current increases, the magnetic field strength increases, and the kinetic energy gained by the projectile also increases. For example, in the first-stage launch circuit, when the MOSFET is turned on, the first-stage energy storage capacitor C1 provides energy to the first-stage launch coil, causing the projectile to begin accelerating.

[0055] When the MOSFET is turned off, the current in the firing coil does not disappear instantly. Instead, it continues to flow through the freewheeling diode and the reverse voltage protection diode. The freewheeling diode provides a freewheeling path for the coil current, allowing it to gradually decrease and preventing damage to circuit components from sudden current changes. Simultaneously, since multiple coil stages are wound around a single barrel, coupling issues can arise between coils during firing of other stages. The reverse voltage protection diode prevents reverse charging caused by this coupling, extending the lifespan of the energy storage capacitor and preventing induced current from hindering changes in magnetic flux density within the barrel, thus ensuring a stable and efficient firing process.

[0056] It is understandable that the launch execution module consists of a primary launch circuit and a secondary launch circuit with the same structure. Each stage consists of a freewheeling diode, a reverse voltage protection diode, a launch coil, and a MOSFET. When the MOSFET is turned on, the energy storage capacitor supplies power to the launch coil, propelling the projectile to accelerate. When the MOSFET is turned off, the diode provides freewheeling current to the coil in time to prevent the MOSFET from being broken down by the self-inductance of the coil.

[0057] Specifically, the sampling circuit is used to acquire various current and voltage signals, including the average current of the charging circuit, the instantaneous inductor current in the bidirectional Buck-Boost circuit, and the voltage across energy storage capacitors C1 and C2. These sampled signals provide the MCU with crucial information about the system's operating status, enabling it to make accurate control decisions based on actual conditions. For example, by sampling the capacitor voltage, the MCU can determine whether the capacitor is fully charged, whether the voltage is too high or too low, and thus decide whether to activate the charging circuit, discharging circuit, or bidirectional Buck-Boost converter circuit to perform the corresponding operation.

[0058] The driver circuit is mainly responsible for converting the signal waveform output by the MCU into a driving waveform with higher voltage and stronger current carrying capacity, so as to drive the MOSFETs in various circuits to turn on or off. Since the MOSFETs play a key role in switching control in the circuit, their normal conduction and turn-off require sufficient driving voltage and current. The driver circuit can meet this requirement, ensuring that the energy conversion and control processes in the circuit proceed smoothly.

[0059] The photoelectric sensors are placed on both sides of the firing coil on the gun barrel and at the initial position of the projectile launch. Their main function is to detect the position of the projectile in the gun barrel. Based on the measured projectile position, the MCU can accurately control the on / off state of the MOSFETs in the multi-stage firing circuit to achieve multi-stage acceleration of the projectile, enabling the projectile to obtain the optimal acceleration effect at the appropriate time and position, thereby improving the accuracy and efficiency of the launch.

[0060] The communication circuit is used to interact with the host computer, enabling data transmission and control signal reception. Through the communication circuit, operators can observe the operating status of the electromagnetic gun on the host computer, including information such as capacitor voltage, current magnitude, and firing status. They can also modify corresponding parameters according to actual needs, such as charging voltage and firing stage, thereby achieving remote monitoring and flexible control of the electromagnetic gun system.

[0061] The MCU and its peripheral circuits are the core of the entire control and monitoring module. The MCU receives various information collected by the sampling circuit and given signals from the host computer to determine the system's operating state. Based on preset algorithms and control strategies, it outputs corresponding drive signals to control the operation of each circuit module. For example, in two-stage transmit mode, the MCU controls the operation of the charging circuit, discharging circuit, and bidirectional Buck-Boost converter circuit based on the voltage across capacitors C1 and C2 relative to a given value, ensuring the system remains stable with appropriate voltages across the two capacitors. In single-stage transmit mode, the MCU controls the operation of each circuit based on the voltage across capacitor C1 and the energy state of capacitor C2, ensuring that capacitor C1 is maintained at a given voltage.

[0062] Specifically, the charging circuit begins operation, sequentially inverting, boosting, and rectifying the DC input to charge the primary energy storage capacitor C1 and the secondary energy storage capacitor C2. During this process, the sampling circuit monitors the charging current, inductor current, and capacitor voltage in real time and transmits this information to the MCU and its peripheral circuits. Based on the received information, the MCU controls the magnitude of the charging current through phase-shift modulation to ensure that the capacitors can be charged safely and stably.

[0063] In two-stage transmit mode, the MCU controls the operation of the charging circuit, discharging circuit, and bidirectional Buck-Boost converter circuit based on the voltages on capacitors C1 and C2 relative to a given value, as collected by the sampling circuit. When one capacitor's voltage is higher than the given value and the other's voltage is lower, neither the charging nor discharging circuit operates; energy flows only between the two capacitors through the bidirectional Buck-Boost converter circuit to balance their voltages. When both capacitor voltages are too high, or one capacitor's voltage is appropriate while the other's is too high, the charging circuit shuts down and the discharging circuit opens. If the voltage on capacitor C2 is too high at this time, the bidirectional Buck-Boost converter circuit needs to be activated to transfer energy to capacitor C1. When both capacitor voltages are lower than the given value, or one capacitor's voltage is appropriate while the other's is too high, the charging circuit opens and the discharging circuit closes. If the voltage on capacitor C2 is lower than the given value at this time, the bidirectional Buck-Boost converter circuit needs to be activated to transfer energy from C1 to C2. If both capacitor voltages are appropriate, all MOSFETs remain off, and the system is ready to transmit.

[0064] In single-stage emitter mode, the MCU controls the operation of each circuit based on the voltage of capacitor C1 and the energy state of capacitor C2. When the voltage of capacitor C1 is too high and the energy stored in C2 has not reached its upper limit, C1 discharges to C2 through a bidirectional Buck-Boost converter circuit; when the voltage of C1 is too high and the energy stored in C2 has reached its upper limit, the discharge circuit is activated to release the excess energy in C1; when the voltage of C1 is too low and there is energy stored in C2, C2 discharges to C1 through a bidirectional Buck-Boost converter circuit; when the voltage of C1 is too low and the energy in C2 is insufficient, the charging circuit needs to be activated to charge C1; when the voltage of C1 is appropriate, all MOSFETs remain off.

[0065] When the system is ready to fire, the photoelectric sensor detects the projectile's position in the barrel and sends the position information to the MCU. Based on the projectile's position information, the MCU controls the switching of MOSFETs in the primary and secondary firing circuits. When the host computer sends a firing command to the MCU, the MCU controls the MOSFET in the primary firing circuit to turn on, and the primary energy storage capacitor C1 supplies power to the primary firing coil, giving the projectile initial acceleration. When the projectile leaves the area of ​​the primary firing coil, the MOSFET in the primary firing circuit turns off, and the primary energy storage capacitor is de-energized. When the projectile moves to the position of the secondary firing coil and is in the two-stage firing state, the MCU controls the MOSFET in the secondary firing circuit to turn on, and the secondary energy storage capacitor C2 supplies power to the secondary firing coil, providing further acceleration for the projectile. When the projectile leaves the area of ​​the secondary firing coil, the MOSFET in the secondary firing circuit turns off, and the secondary energy storage capacitor is de-energized.

[0066] It should be noted that:

[0067] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of this application may be practiced without these specific details. In some instances, well-known structures and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0068] Furthermore, those skilled in the art will understand that although some embodiments described herein include certain features included in other embodiments but not others, combinations of features from different embodiments are meant to be within the scope of this application and form different embodiments.

[0069] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An electromagnetic railgun system with switchable firing stages, characterized in that, include: The charging circuit module is used to convert low-voltage DC power input into high-voltage DC power through inversion, boost and rectification processes. The charging circuit module adjusts the charging current through phase shift control and related mode operation. The charging circuit module consists of a full-bridge inverter circuit, a current-limiting inductor, a transformer and an uncontrolled rectifier circuit. An energy storage module includes a primary energy storage capacitor and a secondary energy storage capacitor. The energy storage module is used to store the energy required to launch the electromagnetic gun. When the two-stage launch occurs, it provides energy to the primary and secondary launch coils respectively. When the single-stage launch occurs, the primary energy storage capacitor supplies energy to the primary launch coil. The secondary energy storage capacitor acts as an energy buffer for the primary energy storage capacitor. Both the primary and secondary energy storage capacitors are electrolytic capacitors. The discharge module uses a discharge circuit to discharge the remaining electrical energy in the energy storage capacitor that exceeds the usage threshold. The discharge circuit consists of a MOS transistor and a discharge resistor, and the discharge circuit is connected in parallel with the first-stage energy storage capacitor. The energy conversion and regulation module utilizes a bidirectional Buck-Boost converter circuit to adjust the voltages of the first-stage and second-stage energy storage capacitors during two-stage transmission, and assists the first-stage energy storage capacitor in energy management during single-stage transmission. The bidirectional Buck-Boost converter circuit consists of MOSFETs S5 and S6 and an energy storage inductor. The bidirectional Buck-Boost converter circuit is connected between the first-stage and second-stage energy storage capacitors, and achieves bidirectional energy flow between the two energy storage capacitors by controlling the on / off state of the MOSFETs. The bidirectional Buck-Boost converter circuit has four operating modes and uses a pop-pop control method to control the current of the energy storage inductor. The transmission execution module consists of a primary transmission circuit and a secondary transmission circuit. Both the primary and secondary transmission circuits include a freewheeling diode, a reverse voltage protection diode, a transmission coil, and a MOSFET. When the MOSFET is turned on, the energy storage capacitor supplies power to the transmission coil. When the MOSFET is turned off, the diode provides freewheeling current to the coil. The control and monitoring module includes a sampling circuit, a driving circuit, a photoelectric sensor, a communication circuit, and an MCU and its peripheral circuits. The sampling circuit is used to collect various current and voltage signals, the driving circuit is used to drive the MOS transistors in each circuit to turn on and off, the photoelectric sensor is used to detect the position of the projectile, the communication circuit is used to interact with the host computer, and the MCU and its peripheral circuits are used to receive information and output driving signals. The charging circuit charges the primary and secondary energy storage capacitors. The sampling circuit monitors the charging current, inductor current, and capacitor voltage in real time and transmits the information to the MCU and its peripheral circuits. In the two-stage launch mode, the MCU controls the operation of the charging circuit, the discharging circuit, and the bidirectional Buck-Boost converter circuit. In the single-stage launch mode, the MCU controls the operation of each circuit and stabilizes the voltage of the primary energy storage capacitor based on the voltage of the primary energy storage capacitor and the energy state of the secondary energy storage capacitor. During launch, the photoelectric sensor detects the projectile position and sends it to the MCU. The MCU controls the switching on and off of the MOSFETs in the primary and secondary launch circuits.

2. The electromagnetic railgun system with switchable firing stages according to claim 1, characterized in that, The full-bridge inverter circuit converts DC to AC by controlling the on / off state of four MOSFETs. During the inversion process, the full-bridge inverter circuit uses phase-shift control to adjust the charging current. The full-bridge inverter circuit has six operating modes. In mode 1, MOSFETs S1 and S4 are turned on, while MOSFETs S2 and S3 are turned off. The current in the current-limiting inductor flows from MOSFET S4 to MOSFET S1. The induced voltage on the primary winding of the transformer is negative, and the voltage across the current-limiting inductor is Uin + Uc1 / N. In mode 2, the MOSFETs... In mode 3, the switching state is the same as in mode 1. After the current in the current-limiting inductor drops to zero, it reverses direction and slowly increases. At this time, the induced voltage of the primary winding of the transformer is positive, and the voltage across the current-limiting inductor is Uin - Uc1 / N. In mode 4, MOSFETs S2 and S4 are turned on, and MOSFETs S1 and S3 are turned off. At this time, the induced voltage of the primary winding of the transformer is still positive, and the voltage across the current-limiting inductor is -Uc1 / N. The current decreases. In mode 5, MOSFETs S2 and S3 are turned on, and MOSFETs S1 and S4 are turned off. The induced voltage of the primary winding of the transformer is positive. The voltage across the current-limiting inductor is -Uin-Uc1 / N, the current direction remains unchanged, and its magnitude decreases rapidly. In mode 5, the switching state of the MOSFETs is the same as in mode 4. After the current in the current-limiting inductor drops to zero, it reverses direction and slowly increases. At this time, the induced voltage of the primary winding of the transformer is negative, and the voltage across the current-limiting inductor is -Uin+Uc1 / N. In mode 6, MOSFETs S1 and S3 are turned on, and MOSFETs S2 and S4 are turned off. At this time, the induced voltage of the primary winding of the transformer is still negative, the voltage across the current-limiting inductor is Uc1 / N, and the current decreases. When the phase shift angle increases, the full-bridge inverter circuit operates in modes 3 and 6 for a longer period of time, the current change of the current-limiting inductor slows down, and the charging current decreases. The current-limiting inductor is connected in series between the full-bridge inverter circuit and the transformer. The transformer boosts the inverted AC power.

3. The electromagnetic railgun system with switchable firing stages according to claim 1, characterized in that, In the two-stage transmission operation, the first-stage energy storage capacitor and the second-stage energy storage capacitor store the energy required by the first-stage transmission coil and the second-stage transmission coil, respectively. When preparing for two-stage transmission, the charging circuit charges the first-stage energy storage capacitor and the second-stage energy storage capacitor, respectively. During the launch process, the first-stage launch coil first uses the energy stored in the first-stage energy storage capacitor to initially accelerate the projectile. When the projectile moves to the position of the second-stage launch coil, the second-stage energy storage capacitor releases energy. When in single-stage transmission mode, the primary energy storage capacitor stores the energy required by the primary transmission coil, and the secondary energy storage capacitor acts as an energy buffer for the primary energy storage capacitor. A 450V 470uF capacitor is selected as the primary energy storage capacitor, and a 450V 330uF capacitor is selected as the secondary energy storage capacitor. When the voltage of the primary energy storage capacitor is higher than the set reference voltage and the secondary energy storage capacitor is not fully charged, the primary energy storage capacitor directly discharges to the secondary energy storage capacitor. When the voltage of the primary energy storage capacitor is lower than the set reference voltage and the secondary energy storage capacitor has electrical energy, the secondary energy storage capacitor charges the primary energy storage capacitor.

4. The electromagnetic railgun system with switchable firing stages according to claim 1, characterized in that, The discharge module operates in two-stage emission mode and single-stage emission mode with the secondary energy storage capacitor fully charged. When the energy in the energy storage capacitor exceeds the threshold, the discharge module releases the excess energy. In two-stage emission mode, when the voltage of both energy storage capacitors is too high or one capacitor voltage is appropriate while the other capacitor voltage is too high, the discharge circuit is activated to release the excess energy. In single-stage emission mode, when the voltage of the primary energy storage capacitor is too high and the energy storage in the secondary energy storage capacitor reaches the upper limit, the discharge circuit is activated to release the excess energy in the primary energy storage capacitor. When the discharge circuit is working, the MOS transistor is turned on, and the excess energy in the primary energy storage capacitor forms a circuit through the discharge resistor, so that the electrical energy is converted into heat energy based on the resistance.

5. The electromagnetic railgun system with switchable firing stages according to claim 1, characterized in that, The source of MOSFET S5 is connected to the drain of MOSFET S6. The drain of MOSFET S5 is connected to the positive terminal of the first-stage energy storage capacitor. The source of MOSFET S6 is connected to the negative terminal of the second-stage energy storage capacitor. One end of the energy storage inductor is connected to the source of MOSFET S5, and the other end is connected to the negative terminal of the first-stage energy storage capacitor and the positive terminal of the second-stage energy storage capacitor. The bidirectional Buck-Boost converter circuit has two operating modes in each of the two energy flow directions, for a total of four operating modes. In mode 1, MOSFET S5 is turned on, MOSFET S6 is turned off, and the current in the energy storage inductor increases, transferring energy from the first-stage energy storage capacitor to the energy storage inductor. In mode 2, both MOSFETs S5 and S6 are turned off, and the current in the energy storage inductor increases. The current in the energy storage inductor flows through the secondary energy storage capacitor and the body diode of the MOSFET S6 to achieve freewheeling. The secondary energy storage capacitor is charged, the voltage increases, and energy is transferred from the energy storage inductor to the secondary energy storage capacitor. In mode 3, the MOSFET S6 is turned on, the MOSFET S5 is turned off, the current in the energy storage inductor increases, and the current direction is opposite to that in mode 1. Energy is transferred from the secondary energy storage capacitor to the energy storage inductor. In mode 4, both MOSFETs S5 and S6 are turned off. The current in the energy storage inductor flows through the primary energy storage capacitor and the body diode of the MOSFET S5 to achieve freewheeling. The primary energy storage capacitor is charged, the voltage increases, and energy is transferred from the energy storage inductor to the secondary energy storage capacitor. When the current in the energy storage inductor exceeds a set threshold, the corresponding switching transistor is turned off.

6. The electromagnetic railgun system with switchable firing stages according to claim 1, characterized in that, When the MOSFET is turned on, the energy storage capacitor supplies power to the transmitting coil, and current flows through the transmitting coil. In the first-stage transmitting circuit, when the MOSFET is turned on, the first-stage energy storage capacitor provides energy to the first-stage transmitting coil. When the MOSFET is turned off, the current in the transmitting coil is freewheeled through the freewheeling diode and the reverse voltage protection diode. The freewheeling diode provides a freewheeling path for the coil current. When other stage transmitting coils are working, the reverse voltage protection diode prevents energy from flowing back into the coils due to mutual inductance. The structures of the first and second stage transmitting circuits are the same.

7. The electromagnetic railgun system with switchable firing stages according to claim 1, characterized in that, The sampling circuit is used to collect the average current of the charging circuit, the instantaneous value of the inductor current in the bidirectional Buck-Boost circuit, and the voltage on the first-stage energy storage capacitor and the second-stage energy storage capacitor. The sampling circuit is used to send the sampling signal to the MCU. The driving circuit converts the signal waveform output by the MCU into a driving waveform to drive the MOS transistors in each circuit to turn on or off; the photoelectric sensor is placed on both sides of the firing coil on the barrel to detect the position of the projectile in the barrel, and the MCU controls the on / off state of the MOS transistors in the multi-stage firing circuit according to the position of the projectile. The communication circuit is used to interact with the host computer, observe the capacitor voltage, current magnitude, and transmission status through the communication circuit, and modify the corresponding parameters according to actual needs; the MCU determines its operating status by receiving various information collected by the sampling circuit and given signals provided by the host computer, and outputs corresponding drive signals according to preset algorithms and control strategies to control the operation of each circuit module. In the two-stage transmission mode, the MCU controls the operation of the charging circuit, the discharging circuit, and the bidirectional Buck-Boost conversion circuit according to the voltage on the primary energy storage capacitor and the secondary energy storage capacitor. In single-stage transmit mode, the MCU controls the operation of each circuit based on the voltage of the first-stage energy storage capacitor and the energy state of the second-stage energy storage capacitor.

8. The electromagnetic railgun system with switchable firing stages according to claim 1, characterized in that, The charging circuit sequentially inverts, boosts, and rectifies the DC input to charge the primary and secondary energy storage capacitors. During the charging process, the sampling circuit monitors the charging current, inductor current, and capacitor voltage in real time and transmits this information to the MCU and its peripheral circuits. The MCU adjusts the charging current based on the received information using phase-shift modulation and achieves constant current charging through PI control. In two-stage transmit mode, the MCU controls the operation of the charging circuit, the discharging circuit, and the bidirectional Buck-Boost converter circuit based on the voltages on the primary and secondary energy storage capacitors relative to a given value, as collected by the sampling circuit. When one capacitor voltage is higher than the given value and the other capacitor voltage is lower than the given value, both the charging circuit and the discharging circuit are turned off, and energy flows between the two capacitors through the bidirectional Buck-Boost converter circuit. When both capacitor voltages are too high, or one capacitor voltage is appropriate and the other capacitor voltage is too high, the charging circuit is turned off and the discharging circuit is turned on. If the voltage on the secondary energy storage capacitor is too high at this time, the bidirectional Buck-Boost converter circuit is turned on to transfer energy to the primary energy storage capacitor. When both capacitor voltages are lower than the given value, or one capacitor voltage is appropriate and the other capacitor voltage is too high, the charging circuit is turned on and the discharging circuit is turned off. If the voltage on the secondary energy storage capacitor is lower than the given value at this time, the bidirectional Buck-Boost converter circuit is turned on to transfer energy from the primary energy storage capacitor to the secondary energy storage capacitor. When both capacitor voltages are appropriate, all MOSFETs remain off. In single-stage transmit mode, the MCU controls the operation of each circuit based on the energy state of the first-stage energy storage capacitor and the second-stage energy storage capacitor; when the voltage of the first-stage energy storage capacitor is too high and the energy stored in the second-stage energy storage capacitor has not reached the upper limit, the first-stage energy storage capacitor discharges to the second-stage energy storage capacitor through the bidirectional Buck-Boost converter circuit. When the voltage of the primary energy storage capacitor is too high and the energy storage in the secondary energy storage capacitor has reached its upper limit, the discharge circuit is activated to release the excess energy in the primary energy storage capacitor. When the voltage of the primary energy storage capacitor is too low and there is energy stored in the secondary energy storage capacitor, the secondary energy storage capacitor discharges to the primary energy storage capacitor through the bidirectional Buck-Boost converter circuit. When the voltage of the primary energy storage capacitor is too low and the energy in the secondary energy storage capacitor is insufficient, the charging circuit is turned on to charge the primary energy storage capacitor; when the voltage of the primary energy storage capacitor is appropriate, all MOSFETs remain off. When preparing to fire, the photoelectric sensor detects the projectile's position in the barrel and sends the position information to the MCU. Based on the projectile's position information, the MCU controls the switching of the MOSFETs in the primary and secondary firing circuits. When the host computer sends a firing command to the MCU, the MCU controls the MOSFETs in the primary firing circuit to turn on, and the primary energy storage capacitor supplies power to the primary firing coil. When the projectile leaves the area of ​​the primary firing coil, the MOSFETs in the primary firing circuit turn off, and the primary energy storage capacitor cuts off its power supply. When the projectile moves to the position of the secondary firing coil and is in a two-stage firing state, the MCU controls the MOSFETs in the secondary firing circuit to turn on, and the secondary energy storage capacitor supplies power to the secondary firing coil. When the projectile leaves the area of ​​the secondary firing coil, the MOSFETs in the secondary firing circuit turn off, and the secondary energy storage capacitor cuts off its power supply.

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