Electromagnetic launching device and method based on zero-crossing commutation of superconducting constant magnetic flux induced current

Abstract

This invention provides an electromagnetic launching device and method based on zero-crossing commutation of superconducting constant magnetic flux induced current. The device includes a drive coil wound with superconducting wire or strip, with multiple drive coils forming a launching channel; a projectile coil wound with superconducting bulk or wire; a superconducting DC power supply providing initial current to the drive coil and projectile coil; and an energy-releasing commutation circuit that utilizes an intermediate capacitor to recover and store the magnetic energy of the superconducting drive coil. Based on this device, by injecting currents of a preset ratio into the superconducting drive coil and the superconducting projectile coil respectively, the current in the superconducting drive coil automatically decays to zero when the superconducting projectile coil moves to the axial center of the superconducting drive coil. This avoids the superconducting drive coil exerting a reverse pulling force on the superconducting projectile coil, ensuring continuous acceleration and launching of the projectile coil. This invention solves the problem of rapid, synchronous, and precise commutation of the launching current in traditional coils.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic launch technology, and more specifically, to an electromagnetic launch device and method based on zero-crossing commutation of superconducting constant magnetic flux induced current. Background Technology

[0002] Electromagnetic launch is a technology that uses the Ampere force between an electric current and a magnetic field to accelerate projectile motion. Currently, the most commonly used coil-type electromagnetic launch method is reluctance coil launch. The key technical challenge of this method lies in rapidly releasing the current in the drive coil when the projectile armature reaches the center to avoid generating a reverse deceleration force. Simultaneously, the control system must be synchronized with the projectile armature's movement, selecting and setting appropriate pre-discharge times and trigger discharge positions to maximize the use of electromagnetic acceleration. However, under conditions of high thrust, ultra-high speed, high current, and multi-stage launch, as the projectile speed increases, the switching pressure on the commutation circuit increases, making it difficult for the current in the drive coil to discharge synchronously, quickly, and accurately. Summary of the Invention

[0003] The purpose of this invention is to provide an electromagnetic launching device and method based on zero-crossing commutation of superconducting constant magnetic flux induced current, in order to solve the problem of reverse deceleration force generated when the projectile reaches the center of the driving coil because the current cannot be released in time. This invention proposes using superconducting wire to wind the driving coil, using superconducting bulk material to fabricate the projectile armature, designing an energy release commutation circuit to transfer magnetic energy, and providing a method for calculating the proportional value that enables the driving coil current to automatically cross zero.

[0004] This invention solves the problem of excessive internal resistance loss in traditional coil-type emission mode, overcomes the difficulty of rapid and accurate commutation of the driving coil current, and reduces the switching pressure of the energy release circuit commutation switch, effectively solving the problem of braking and deceleration force during the launch of the projectile coil, and effectively improving the efficiency of coil-type electromagnetic emission.

[0005] The embodiments of the present invention are achieved through the following technical solutions:

[0006] In a first aspect, an electromagnetic transmitting device based on zero-crossing commutation of superconducting constant flux induced current is provided, comprising a driving coil, wherein the driving coil is wound with superconducting wire or strip, and multiple driving coils form a transmitting channel; a projectile coil, wherein the projectile coil is wound with superconducting bulk material or wire; and a superconducting DC power supply, wherein the superconducting DC power supply is used to provide initial current for the driving coil and the projectile coil.

[0007] Secondly, an electromagnetic transmission method based on zero-crossing commutation of superconducting constant magnetic flux induced current is applied to the aforementioned electromagnetic transmission device based on zero-crossing commutation of superconducting constant magnetic flux induced current; the transmission method is as follows:

[0008] Before launch, a superconducting DC power supply is used to excite and charge the superconducting drive coil to the required current. Then, the superconducting switch is closed, causing the superconducting drive coil to be energized. Closed-loop operation;

[0009] At the initial moment of launch, the superconducting projectile coil is energized and charged using a superconducting DC power supply, thereby generating current in the superconducting projectile coil. And current and The directions are consistent; then the superconducting switch is closed to make the superconducting parabolic coil operate in a closed loop;

[0010] During launch, the currents in the superconducting drive coil and the superconducting projectile coil are in the same direction, generating an attractive electromagnetic force that pulls the projectile coil to accelerate. As the superconducting projectile coil approaches the drive coil, due to electromagnetic induction and the principle of superconducting constant magnetic flux, the current in the superconducting drive coil increases... It will continue to decrease.

[0011] By setting a preset initial current, the current in the superconducting drive coil can be such that when the superconducting projectile coil moves to the center point of the superconducting drive coil, the current in the superconducting drive coil is... It automatically decays to zero. At this point, the first circuit of the energy release commutation circuit is disconnected, and the energy is simultaneously commutated to the second circuit to store magnetic energy.

[0012] The technical solutions of the embodiments of the present invention have at least the following advantages and beneficial effects:

[0013] By injecting currents of a preset ratio into the superconducting drive coil and the superconducting projectile coil respectively, that is, the magnetic flux of the superconducting projectile coil and the magnetic flux of the superconducting drive coil satisfy a preset ratio relationship, when the midpoint of the superconducting projectile coil is located at the axial center of the superconducting drive coil, the current in the superconducting drive coil automatically decays to zero, thereby avoiding the superconducting drive coil from generating a reverse pulling force on the superconducting projectile coil.

[0014] The proposed technical solution can solve the problem of excessive internal resistance loss in traditional coil-type launch modes, overcome the difficulty of rapid and accurate commutation of the drive coil current, and reduce the switching pressure of the energy release circuit commutation switch, effectively solving the problem of braking and deceleration forces during projectile coil launch. This launch mode fully recovers and utilizes coupled magnetic energy, avoiding the loss of residual magnetic energy in traditional coil launchers, and effectively improving the efficiency of coil-type electromagnetic launch. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the superconducting constant magnetic flux induction emission principle of the present invention;

[0016] Figure 2 This is a diagram showing the automatic zero-crossing of the superconducting constant flux induction transmitting coil current of the present invention.

[0017] Figure 3 This is a flowchart of the superconducting constant magnetic flux induction emission method of the present invention;

[0018] Figure 4 This is a block diagram of the superconducting constant flux induction emission system of the present invention;

[0019] Figure 5 This is a schematic diagram of the energy release commutation circuit of the present invention;

[0020] Figure 6 The current variation curves of the transient process drive coil and the projectile coil of the present invention are shown.

[0021] Figure 7 This is a graph showing the acceleration force and velocity variation of the projectile coil during the transient process of the present invention. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0023] This invention employs superconducting wire to wind the drive coil and uses superconducting bulk or wire materials to fabricate the projectile coil, proposing a novel electromagnetic launch mode based on zero-crossing commutation of the superconducting constant magnetic flux induced current. This launch mode uses a superconducting DC power supply to inject current into the drive coil and the projectile coil. A preset current operates in a closed loop within both the drive and projectile coils, generating a magnetic field. The magnetic fields of the two coils attract each other, resulting in acceleration. According to the principles of electromagnetic induction and Lenz's repulsive flux, as the projectile coil approaches the drive coil, the current in the drive coil continuously decreases. By appropriately setting the preset current, the current in the drive coil automatically decays to zero when the projectile coil reaches the axial center point of the drive coil. At this point, the original circuit of the drive coil is disconnected, and the temporarily stored commutation magnetic energy is recovered using an intermediate capacitor, ensuring that the projectile coil is not subjected to a reverse deceleration force. This launch mode significantly reduces the switching pressure of the drive coil current commutation. Simultaneously, the intermediate capacitor can discharge to the latter half of the next-stage drive coil, thereby generating a repulsive force to accelerate the projectile coil. Thus, a full-range acceleration of the projectile coil is achieved through a pull-and-push mechanism from the superconducting drive coil. This transmission mode fully recovers and utilizes the coupled magnetic energy, avoiding the loss of residual magnetic energy in traditional coil transmitters, which can greatly improve the system's transmission efficiency.

[0024] The principle of the novel electromagnetic launch mode based on zero-crossing commutation of superconducting constant magnetic flux induced current is as follows:

[0025] Superconductors exhibit zero resistance and the Meissner effect. When a superconducting coil is wound with superconducting wire and current flows through it, and the coil is closed-loop through a superconducting switch, the current in the superconducting coil loop will remain constant because the resistance of the loop tends to be zero. This is the law of conservation of superconducting magnetic flux.

[0026] Based on the law of conservation of superconducting flux, consider two coaxially placed superconducting coils, such as Figure 1 As shown, one is a parabolic coil. One as a driving coil The inductance of the drive coil is The operating current is The inductance of the parabolic coil is The operating current is The mutual inductance between the drive coil and the projectile coil is... The mutual inductance value changes as the projectile coil moves. The mutual inductance value is at its maximum when the projectile coil moves to the center of the drive coil.

[0027] Before launch, the projectile coil and drive coil are energized by a superconducting DC power supply. Once the set initial current value is reached, a superconducting switch is used to close the loop. Due to the resistance-free nature of the superconducting wire, the closed-loop current in the superconducting coil can operate continuously. Without external electromagnetic interaction or energy loss, the magnetic flux in each loop of the drive coil and projectile coil remains constant. If the current directions in the projectile coil and drive coil are aligned, the projectile coil will be accelerated by the attractive force of the drive coil.

[0028] At the initial moment of launch, assume the center point of the projectile coil and the drive coil are at a distance of... The initial mutual inductance between the projectile coil and the drive coil is Their initial currents are respectively , The magnetic fluxes of the projectile coil and the driving coil are respectively:

[0029] (1)

[0030] (2)

[0031] During launch, the projectile coil continuously approaches the drive coil, causing the mutual inductance between the two coils to change. Due to electromagnetic induction, the current values ​​in their respective circuits will also change. If the magnetic flux of the projectile coil is greater than that of the drive coil, the current in the drive coil will gradually decrease. When the projectile coil accelerates to the axial center point of the drive coil, the mutual inductance between the drive coil and the projectile coil is... At this time, if the current in the drive coil... It just decreases to zero, and the current in the projectile coil is Ignoring the resistance of the circuit and switches, based on the flux conservation characteristics of the superconducting coil circuit, we get...

[0032] (3)

[0033] (4)

[0034] By combining equations (1), (2), (3), and (4), the ratio of the initial projectile coil current to the driving coil current can be obtained. k for:

[0035] k = (5)

[0036] Equation (5) above represents the condition that the current in the driving coil decays to zero when the projectile coil reaches the axial center position of the driving coil, which is also the condition for achieving automatic zero-crossing of the current. This condition requires that the currents of the projectile coil and the driving coil initially satisfy the zero-crossing ratio coefficient. k This ratio is determined by the inductance of the projectile coil and the drive coil at the initial position. , Mutual induction And the mutual induction when the centers of the two coincide. Decide. Figure 2 The curves show the current variations of the two coils in the superconducting constant flux induction emission system, where the driving coil current is... I d1 Automatic decay to zero.

[0037] Based on the above-mentioned implementation principle, this invention provides an electromagnetic launch method based on zero-crossing commutation of superconducting constant magnetic flux induced current, such as... Figure 3 As shown, this method can be applied to electromagnetic launching devices based on zero-crossing commutation of superconducting constant magnetic flux induced current. The system block diagram is shown below. Figure 4 As shown; specifically as follows:

[0038] Before launch, a superconducting DC power supply is used to excite and charge the superconducting drive coil to the required current. Then, the superconducting switch is closed, causing the superconducting drive coil to be energized. Closed-loop operation;

[0039] At the initial launch moment, the superconducting projectile coil is energized and charged using a superconducting DC power supply. Based on the aforementioned principle of automatic zero-crossing of the superconducting constant magnetic flux induced current, the ratio of the initial projectile coil current to the drive coil current is calculated to meet a preset ratio value. k This allows the superconducting parabolic coil to reach the required current. And current and The directions are consistent; then the superconducting switch is closed to make the superconducting parabolic coil operate in a closed loop;

[0040] During launch, the currents in the superconducting drive coil and the superconducting projectile coil are in the same direction, generating an electromagnetic force that attracts each other. The projectile coil will be accelerated by the attraction of the drive coil.

[0041] As the superconducting projectile coil approaches the drive coil, the mutual inductance and coupling flux between the two coils continuously increase, while the current in the superconducting drive coil continuously decreases. Through the aforementioned initial current setting, it can be ensured that when the projectile coil reaches the axial center point of the drive coil, the current in the drive coil automatically decays to zero. At this point, the first circuit of the drive coil can be easily disconnected, while the second commutation circuit closes. The intermediate capacitor releases and recovers the temporarily stored commutation magnetic energy, ensuring that the current in the drive coil remains zero. This prevents the projectile coil from experiencing a reverse deceleration force. The hybrid commutation circuit is as follows: Figure 5 As shown.

[0042] In the above process, the superconducting driving coil can be a single-stage driving coil or a combination of multiple driving coils; it should be noted that even in the application scenario of multi-stage driving coils, the initial current ratio of the projectile coil to each stage driving coil still conforms to the ratio in formula (5). k Furthermore, the circuit structure, current change process, and switch closing conditions of each stage of the drive coil are consistent with the above process.

[0043] This section further validates the above method through a simulation example. A superconducting constant flux induction coil launching model and coupled power supply circuit are established in engineering electromagnetic field simulation software. First, at the initial position, the inductances of the projectile coil and the driving coil are calculated using the static magnetic field module. L d , L p , and the mutual intuition between the two M 1. Then, calculate the mutual inductance between the projectile coil and the drive coil when their centers coincide. M 0. Based on the zero-crossing proportional coefficient formula derived from the aforementioned theory, if the preset current of the superconducting projectile coil is 2000A, then the initial current of the superconducting drive coil should be 1052A. The launch process is simulated and calculated using a transient electromagnetic field module. The mass of the projectile coil is set to 0.125kg, the initial velocity to 10m / s, and the acceleration distance to 100mm. The transient coupling circuit is as follows: Figure 5 As shown, the commutator switch Sd1 is controlled by a position sensor. It is set that when the projectile coil moves to the center of the drive coil, the commutator switch Sd1 opens, and the superconducting drive coil Ld1 discharges energy to the intermediate capacitor C1. Diode D1 limits the unidirectional current flow. The transient simulation results are as follows: Figure 6 , 7The figures shown are the current variation curves in the superconducting drive coil and the projectile coil, and the acceleration force and velocity variation curves of the projectile coil, respectively.

[0044] Based on the above principles and methods, the electromagnetic launching device based on zero-crossing commutation of superconducting constant magnetic flux induced current provided in this application includes a drive coil, a projectile coil, a superconducting DC power supply, and an energy release commutation circuit. The drive coil is wound with superconducting wire or tape. Due to the zero resistance and Meissner effect of superconductors, when a superconducting coil is wound with superconducting wire and current flows through it in a closed loop via a superconducting switch, the current in the superconducting coil loop will remain constant or experience a small attenuation because the resistance of the loop tends to be zero, achieving a certain degree of magnetic flux conservation. In this application, multiple drive coils constitute a launching channel.

[0045] In one embodiment, the launch channel is composed of a cascade of multiple drive coils spaced apart on the same straight line. This is a relatively simple launch channel arrangement. Although its upper limit of the acceleration it can generate for the projectile is insufficient to reach the ideal height, it still has many applications. For example, it can be applied to scenarios such as electromagnetic guns launching projectiles, where the projectile receives continuous acceleration during launch as it passes through the launch channel composed of multiple cascaded drive coils; of course, it is understood that its applications are not limited to this.

[0046] In some applications, it is necessary to generate a large acceleration for heavy objects in a short period of time. Using only the previously mentioned launch channel arrangement would require an unbearable current. Therefore, an alternative launch channel arrangement is needed: the launch channel consists of a multi-stage, multi-pole coil group extending along the direction of motion of the projectile coil. With the same launch channel length, this method results in greater magnetic energy coupling between the electromechanical system and the projectile, thus generating a more powerful electromagnetic force to accelerate it. This launch channel can be applied to locomotive propulsion, rocket boosting, shipborne electromagnetic catapults, and vacuum tube transportation.

[0047] The projectile coil is made of superconducting bulk material or superconducting wire. It is known that in traditional electromagnetic launching, the projectile is generally made of iron core or other metal bulk material. However, ferromagnetic projectiles are easily magnetized and suffer from magnetic saturation in strong electromagnetic launching, leading to a decrease in launching performance. Furthermore, the use of such traditional projectiles requires precise control of the drive coil current; that is, when the midpoint of the projectile moves to the axial center point of the drive coil, the current needs to be switched off and reversed in time. Otherwise, the attractive force will reduce the acceleration of the projectile, significantly reducing the exit velocity. Based on this problem, this application proposes using a projectile coil made of superconducting bulk material or wire to replace the traditional projectile. It should be noted that the projectile coil can be embedded in a non-metallic bulk material or wound on the surface of a non-metallic bulk material. When using such a projectile coil, a preset current value needs to be injected before launching. It is particularly important to note that the magnetic flux in the projectile coil and the magnetic flux in the drive coil should meet a preset ratio. Furthermore, during the launch process, due to electromagnetic induction and Lenz's resistance flux principle, as the projectile coil approaches the drive coil, the current in the drive coil will continuously decrease, which will cause the midpoint of the current in the drive coil to decay to zero when the projectile coil moves to the center of the drive coil.

[0048] The main function of the superconducting DC power supply is to provide current to the drive coil and the projectile coil. The drive coil is directly connected to the superconducting DC power supply. When the current reaches a preset value, the superconducting switch closes, allowing the preset current to operate in a closed loop within the superconducting coil. This superconducting switch can be a traditional thermally controlled, magnetically controlled, or semiconductor-controlled switch, etc. It is understood that the superconducting switch is not limited to these types.

[0049] A superconducting DC power supply can provide current to the projectile coil in a contactless manner. In this case, a starting coil is required, positioned at the initial launch position of the projectile coil. This starting coil is connected to an energy storage capacitor via a switch. When the switch is closed, the energy storage capacitor pulses and discharges to the starting coil, inducing a current in the projectile coil at the initial launch position. Alternatively, this application can also use a flux pump to excite and power the projectile coil.

[0050] To prevent the current in the drive coil from failing to decay to zero when the projectile coil moves to the axial center of the drive coil, the present invention also includes a position sensor. The position sensor is used to monitor the position of the projectile coil. When the position sensor detects that the projectile coil has moved to the axial center of the drive coil, it disconnects the current loop of the drive coil and / or opens the reverse switch, thereby avoiding the generation of reverse pulling force.

[0051] It is understood that the aforementioned position sensor can be a laser ranging device set at the initial emission position of the projectile coil; or it can be a photoelectric position monitoring sensor set at the axial center of the drive coil.

[0052] The driving coil in this invention is also connected to an energy release commutation circuit. In one embodiment, the energy release commutation circuit includes a first circuit and a second circuit, such as... Figure 5 As shown; the first circuit includes a drive coil, a resistor R1, and a switch Sd1 connected in sequence, while the second circuit includes a drive coil, a resistor R1, a diode D1, and an intermediate capacitor C1 connected in sequence; where R2 is the internal resistance of the circuit. The switch Sd1 here is a superconducting switch or a thyristor commutation switch.

[0053] It should be noted that the intermediate capacitor C1 in the second circuit prevents large induced voltages from appearing across the superconducting drive coil, thus providing protection. Additionally, the intermediate capacitor C1 can collect energy to prepare for discharging into the latter half of the next stage drive coil, thereby generating a repulsive force to accelerate the projectile coil. This achieves full-range acceleration of the projectile coil by first pulling and then pushing it, as required by the superconducting drive coil.

[0054] By injecting currents of a preset ratio into the superconducting drive coil and the superconducting parabolic coil respectively, that is, the magnetic flux in the parabolic coil and the magnetic flux in the drive coil should meet the preset ratio, when the midpoint of the superconducting parabolic coil is located at the axial center of the superconducting drive coil, the current in the superconducting drive coil decays to 0, which also reduces the switching pressure of the commutator in the circuit.

[0055] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An electromagnetic launching device based on zero-crossing commutation of superconducting constant magnetic flux induced current, characterized in that, include: A driving coil, wherein the driving coil is wound with superconducting wire or strip, and multiple superconducting driving coils form a transmission channel; A parabolic coil, wherein the parabolic coil is wound with superconducting bulk material or superconducting wire; A superconducting DC power supply, which is used to provide initial current for the superconducting drive coil and the projectile coil; An energy-releasing commutation circuit is provided, which utilizes an intermediate capacitor to recover and store the magnetic energy of a superconducting drive coil. The energy-releasing commutation circuit includes a first circuit and a second circuit. The first circuit includes a superconducting drive coil, a resistor R1, and a switch Sd1 connected in sequence. The second circuit includes a superconducting drive coil, a resistor R1, a diode D1, and an intermediate capacitor C1 connected in sequence. The switch Sd1 is a superconducting switch or a thyristor commutation switch. The zero-crossing commutation specifically refers to the following: when the superconducting parabolic coil moves to the axial center point of the superconducting drive coil, the current in the superconducting drive coil automatically decays to zero, the first circuit of the energy release commutation circuit is disconnected, and at the same time the second commutation circuit is closed to transfer magnetic energy.

2. The electromagnetic launching device based on zero-crossing commutation of superconducting constant flux induced current as described in claim 1, characterized in that, It also includes a position sensor for monitoring the location of the projectile coil.

3. The electromagnetic launching device based on zero-crossing commutation of superconducting constant magnetic flux induced current as described in claim 1, characterized in that, A current detection device is also provided at the switch Sd1 to detect the current in the superconducting drive coil.

4. The electromagnetic launching device based on zero-crossing commutation of superconducting constant magnetic flux induced current as described in claim 1, characterized in that, It also includes a starting coil. The initial current in the superconducting projectile coil is obtained by pulse discharge induction of the starting coil, that is, by pulse discharge to the starting coil through the energy storage capacitor, so that the projectile coil located at the initial launch position generates an induced current.

5. The electromagnetic launching device based on zero-crossing commutation of superconducting constant flux induced current as described in claim 1, characterized in that, The launch channel is composed of multiple superconducting drive coils cascaded at intervals on the same axis.

6. The electromagnetic launching device based on zero-crossing commutation of superconducting constant magnetic flux induced current as described in claim 1, characterized in that, The transmission channel is composed of a multi-stage multipole coil group, which extends along the direction of motion of the projectile coil.

7. An electromagnetic launch method based on zero-crossing commutation of superconducting constant magnetic flux induced current, characterized in that, Applied to the electromagnetic transmitting device based on zero-crossing commutation of superconducting constant magnetic flux induced current as described in any one of claims 1-6; the transmitting method is as follows: The superconducting drive coil is energized and charged to the required current using a superconducting DC power supply. Then, the superconducting switch is closed, causing the superconducting drive coil to be energized. Closed-loop operation; At the initial launch moment, the superconducting projectile coil is energized and charged using a superconducting DC power supply, thereby generating current in the superconducting projectile coil. And current and The directions are consistent; then the superconducting switch is closed to make the superconducting parabolic coil operate in a closed loop; When the superconducting parabolic coil moves to the axial center point of the superconducting drive coil, the current in the superconducting drive coil... When the automatic decay crosses zero, the first circuit of the energy release commutation circuit is disconnected, and at the same time the second commutation circuit is closed to transfer magnetic energy.

8. The electromagnetic launch method based on zero-crossing commutation of superconducting constant flux induced current as described in claim 7, characterized in that, The magnetic flux of the superconducting projectile coil is greater than that of the superconducting drive coil, and the current... With current The ratio is k =( L p L d - M 0 M 1) / ( L p M 0- L p M 1); in, L d The inductance of the superconducting drive coil, L p For the inductance of a superconducting parabolic coil, M 0 represents the mutual inductance when the midpoint of the superconducting parabolic coil is located at the axial center of the superconducting drive coil. M 1 represents the mutual inductance between the superconducting projectile coil and the superconducting drive coil when the launch is in its initial position.

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