Circuit suitable for theta-pinch forming field anti-configuration device and device thereof

Abstract

The invention discloses a circuit suitable for a theta-pinch formation field anti-configuration device and a device thereof, and relates to the technical field of nuclear fusion devices. The switch device K2 and the capacitor device C2 are additionally arranged on the basis of the traditional branch circuit, the pre-ionization branch circuit and the bias branch circuit are integrated, the functions of the pre-ionization branch circuit and the bias branch circuit are achieved by controlling the working time sequence through a switch, the number of power devices needed by the system is reduced, the pre-ionization branch circuit and the bias branch circuit are combined into one, and the power consumption of the system is reduced. And the circuit structure, the size and the weight are reduced, and the requirements on cables, connectors, chargers, radiators and system cabinets are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of nuclear fusion devices, and in particular to a circuit and a device suitable for a θ-pinch field inversion device. Background Art

[0002] Nuclear fusion energy is a potential important path to solve human energy problems. Deuterium-deuterium and deuterium-tritium nuclear fusion are two common forms of nuclear fusion reactions. Deuterium can be extracted cheaply from seawater, and tritium can be produced using abundant natural lithium. Fusion fuel is abundant and easy to obtain. Compared with traditional uranium and plutonium nuclear fission materials, deuterium-deuterium and deuterium-tritium fusion reactors will not produce highly radioactive, long-term nuclear waste, and fusion reactors will not cause core meltdown due to uncontrollable high temperatures caused by nuclear reactions, so as not to cause irreparable losses. Therefore, deuterium-deuterium or deuterium-tritium nuclear fusion can be used as a clean energy to play a role in mitigating climate change in the future, and its research significance and application prospects are increasingly worthy of attention.

[0003] In the deuterium-deuterium and deuterium-tritium nuclear fusion schemes based on field reversed configuration (FRC), the θ-pinch is the most traditional and common method of forming field reversed configuration, but the existing field reversed configuration forming devices have the problems of high cost and large size, which has become an obstacle to the commercialization of nuclear fusion devices for power generation. Figure 1 As shown, the circuit device is mainly composed of four electrical branches, a magnetic coil and a vacuum chamber. Each branch is composed of a capacitor and a switch, among which branch ① is a field reversal branch, branch ② is a pre-ionization branch, branch ③ is a bias branch, branch ④ is a freewheeling / energy discharge branch, and branch ⑤ is a θ-pinch coil in a field inversion configuration, which can actually be regarded as an inductor. The sequential discharge of branches ① to ④ to branch ⑤ (coil) corresponds to the four stages of the field anti-plasma formation process. The function of this circuit is actually to construct a resonant condition for the RLC second-order resonant circuit. Considering the needs of actual work, this circuit is divided into three main electrical branches: field reversal branch (Main), pre-ionization branch (PI), and bias branch (Bias), see Figure 2 As shown, each branch is configured with its own Crowbar branch (energy dissipation) structure. The electrical parameters of each electrical branch and the instantaneous voltage and current generated during operation are quite different. The overall system is relatively complex, and the entire system uses a large number of power components, resulting in a high cost.

[0004] At present, the power device suitable for the second-order resonant reaction of the θ-pinch coil is a three-gap deuterium-filled metal-ceramic hollow anode structure high-power thyristor, which has the characteristics of large peak anode current, high switching power, and high repetition frequency, and can be used as a fast discharge high-power pulse switch. However, the unit cost of hydrogen thyristors is relatively high, and a set of FRC power supplies includes a field reversal branch (Main), a pre-ionization branch (PI), a bias branch (Bias), and a freewheeling / energy dissipation branch for each branch. Overall, more hydrogen thyristors are required, the system cost is high, and the system volume and weight are larger. Summary of the invention

[0005] The present invention provides a circuit and a device suitable for a θ-pinch field inversion device, so as to solve the problems of complex circuit, high construction cost and large volume in the existing device.

[0006] The present invention is achieved through the following technical solutions:

[0007] In a first aspect of the present invention, there is provided a circuit suitable for forming a field inversion configuration device of θ-pinch, comprising:

[0008] θ-pinch coil inductance;

[0009] The pre-ionization and bias branch includes a first high-voltage DC source U1, a first switch K1 and a first capacitor C1 connected in series with the first high-voltage DC source U1, a second switch K2 connected in parallel with the first capacitor C1, a third switch K3 and a second capacitor C2 connected in series with the second switch K2, and a first discharge branch; the first capacitor C1, the third switch K3, the second capacitor C2 and the θ-pinch coil inductor are connected in series to form a loop to achieve pre-ionization, the second switch K2, the third switch K3, the second capacitor C2 and the θ-pinch coil inductor are connected in series to form a loop to achieve bias, and the first discharge branch is connected in series with the θ-pinch coil inductor to form a discharge loop;

[0010] The field reversal branch includes a second high-voltage DC source U2, a fourth switch K4 connected in series with the second high-voltage DC source U2, a third capacitor C3 connected in parallel with the second high-voltage DC source U2 and the fourth switch K4, a fifth switch K5 connected in series with the third capacitor C3, and a second discharge branch. The third capacitor C3, the fifth switch K5 and the θ-pinch coil inductor are connected in series to form a loop, and the second discharge branch is connected in series with the θ-pinch coil inductor to form a discharge loop.

[0011] The circuit of the present invention is suitable for a device that uses a θ-pinch coil to constrain the plasma configuration. By adding a switch device K2 and a capacitor device C2 on the basis of a traditional branch structure, the pre-ionization branch and the bias branch are integrated, and the functions of the pre-ionization branch and the bias branch are realized by controlling the working sequence through a switch. After the charging of capacitor C1 is completed in the first stage, in the second stage, switch K1 is disconnected, K2 is disconnected, and K3 is closed, so that capacitor C1 charges capacitor C2 and the inductance of the θ-pinch coil, and capacitor C1, capacitor C2, and the θ-pinch coil have a second-order resonance, and the resonant current gradually decreases to a sufficiently small value, and the charge stored in capacitor C1 is transferred to capacitor C2. In the third stage, switch K3 remains on and switch K2 is closed, and the current flows along capacitor C2-switch K3-switch K2-θ-pinch coil inductance-capacitor C2, and the current direction is reversed, and capacitor C2 and the θ-pinch coil inductance have a second-order resonance. In the last stage, a release path is provided for the energy stored in the inductance of the θ-pinch coil through the discharge branch. Therefore, after adding the switch device K2 and the capacitor device C2, the functions of the original two branches are realized through the pre-ionization and bias branches, the circuit is simpler, the device consumption is reduced, especially the demand for thyristors, and the cost and volume of the device are reduced.

[0012] Furthermore, the first discharge branch and the second discharge branch are both composed of a resistor and a control switch connected in series, and are used for the θ-pinch coil inductance to release charge.

[0013] Furthermore, the third switch, the fifth switch, and the control switches of the first discharge branch and the second discharge branch are hydrogen thyristors.

[0014] Furthermore, the pre-ionization and bias branch and the field reversal branch share a discharge circuit, and the shared discharge circuit is formed by merging the first discharge branch and the second discharge branch and connecting them in series with the θ-pinch coil inductance.

[0015] Furthermore, the second switch K2 is also connected in series with an inductor L1 , and the second switch K2 , the inductor L1 , the third switch K3 , the second capacitor and the θ-pinch coil inductor L are connected in series to form a loop.

[0016] Furthermore, the voltage output directions of the first high-voltage DC source U1 and the second high-voltage DC source U2 are the same.

[0017] Furthermore, the pre-ionization and bias branch realizes pre-ionization and bias through switch timing control, including:

[0018] Preparation stage: the first switch K1 is turned on, the second switch K2, the third switch K3 and the first discharge branch are turned off, and the first high-voltage DC source U1 charges the first capacitor C1;

[0019] Pre-ionization stage: the third switch K3 is turned on, the first switch K1, the second switch K2 and the first discharge branch are turned off, at this time the capacitor C1 immediately starts to discharge, and the current releases the charge along the first capacitor C1-third switch K3-second capacitor C2-θ-pinch coil inductance-first capacitor C1, forming a second-order resonant model, in which C1 and C2 are in series;

[0020] Bias stage: In the pre-ionization stage working state, when the resonant current gradually decreases to a sufficiently small value, the charge stored in the first capacitor C1 is transferred to the second capacitor C2. At this time, the first switch K1, the second switch K2 and the first discharge branch remain disconnected, the third switch K3 is still turned on and the second switch K2 is closed, and the second capacitor releases the charge immediately. At this time, the current flows along the second capacitor C2-third switch K3-second switch K2-θ-pinch coil inductance-second capacitor C2, and the current direction is reversed compared to the pre-ionization stage.

[0021] Furthermore, in the pre-ionization stage, the first capacitor C1 and the second capacitor C2 resonate with the θ-pinch coil inductance L in the second order, and the circuit satisfies the following resonance formula:

[0022]

[0023] u c1 =u c2 +u L

[0024]

[0025] Among them, i c1 is the current flowing out of the first capacitor C1, i c2 is the current flowing into the second capacitor C2, i L is the current flowing through the inductance of the θ-pinch coil, u c1 is the voltage across the first capacitor C1, u c2 is the voltage across the second capacitor C2, u L is the voltage across the inductance of the θ-pinch coil, and t is the time;

[0026] Since the first capacitor C1 and the second capacitor C2 are connected in series and resonate with the θ-pinch coil inductance in the second order, the following formula also exists:

[0027]

[0028] Wherein, L is the equivalent inductance of the θ-pinch coil, C1 is the capacitance of the first capacitor C1, C2 is the capacitance of the second capacitor C2, C res1is the equivalent capacitance of the first capacitor C1 and the second capacitor C2 connected in series, τ1 is the inductance L and the series capacitor C res1 The time constant of the circuit, f res1 is the inductor L and the series capacitor C res1 The resonant frequency of the circuit.

[0029] Furthermore, in the biasing stage, the second capacitor C2 and the inductance of the θ-pinch coil undergo second-order resonance, and the circuit satisfies the following resonance formula:

[0030]

[0031] -u c2 =-u L

[0032]

[0033] Where, L is the equivalent inductance of the θ-pinch coil, C2 is the capacitance of the second capacitor C2, i c2 is the current flowing out of the second capacitor C2, i L is the current flowing through the inductance of the θ-pinch coil, u c2 is the voltage across the second capacitor C2, u L is the voltage across the inductance of the θ-pinch coil, and t is the time;

[0034] Since the second capacitor C2 and the θ-pinch coil inductor have a second-order resonance, the following formula also exists:

[0035]

[0036] C res2 =C2

[0037] Where, L is the equivalent inductance of the θ-pinch coil, C2 is the capacitance of the second capacitor C2, C res2 is the equivalent capacitance of the second capacitor C2, τ2 is the inductance L and the series capacitor C res2 The time constant of the circuit, f res2 is the inductor L and the series capacitor C res2 The resonant frequency of the circuit.

[0038] A second aspect of the present invention provides a device suitable for forming a field inversion configuration by a θ-pinch, comprising a circuit suitable for forming a field inversion configuration by a θ-pinch as described in any one of the first aspects of the present invention.

[0039] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0040] The new branch circuit topology is adopted to reduce the number of power devices (such as hydrogen thyristors) required in the system;

[0041] Combining the PI branch and the Bias branch into one reduces the circuit structure, volume and weight, and reduces the demand for cables, connectors, chargers, heat sinks and system cabinets. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, other relevant drawings can be obtained based on these drawings without creative work. In the drawings:

[0043] Figure 1 It is a structural diagram of the conventional FRC power supply system;

[0044] Figure 2 It is the circuit topology diagram of a single branch of a traditional FRC power supply system;

[0045] Figure 3 This is the circuit topology diagram of the unified FRC power supply system;

[0046] Figure 4 It is a schematic diagram of the appearance of a high-power thyratron;

[0047] Figure 5 It is a wiring diagram of a high power thyratron;

[0048] Figure 6 is a circuit topology diagram of a single branch circuit of an improvement of an embodiment of the present invention;

[0049] Figure 7 is a schematic diagram of the first working stage of a single branch circuit of an improvement of an embodiment of the present invention;

[0050] Figure 8 is a schematic diagram of the second working stage of a single branch circuit of an improvement of an embodiment of the present invention;

[0051] Fig. 9 is a schematic diagram of the third working stage of a single branch circuit of an improvement of an embodiment of the present invention;

[0052] Fig.10 is a circuit schematic diagram of an improved device for forming a field inversion configuration of θ-pinch according to an embodiment of the present invention;

[0053] Fig.11 It is a circuit principle diagram of another improved device for forming a field inversion configuration of θ-pinch according to an embodiment of the present invention;

[0054] Fig.12 It is a circuit schematic diagram of another improved device for forming a field inversion configuration of the θ-pinch according to an embodiment of the present invention. DETAILED DESCRIPTION

[0055] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0056] It should be noted that the terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to or inherent to other steps or units of the device.

[0057] The terms used in the various embodiments of the application are only used to describe the purpose of specific embodiments and are not intended to limit the various embodiments of the application. As used herein, the singular form is intended to also include the plural form, unless the context clearly indicates otherwise. Unless otherwise limited, all terms used here (including technical terms and scientific terms) have the same meaning as the meanings commonly understood by ordinary technicians in the field of the various embodiments of the application. The terms (such as the terms defined in the dictionary generally used) will be interpreted as having the same meaning as the contextual meaning in the relevant technical field and will not be interpreted as having an idealized meaning or an overly formal meaning, unless clearly defined in the various embodiments of the application.

[0058] See also Figure 1-3 As shown in the figure, the traditional FRC power supply system is mainly composed of four electrical branches ①~④, a magnetic coil ⑤ and a vacuum chamber ⑥. Each branch consists of a capacitor and a switch, where branch ① is a field reversal branch (Main), which is used to generate a reverse magnetic field, branch ② is a preionization branch (PI), which is used to ionize neutral gas to form plasma by high-frequency oscillation, branch ③ is a bias branch (Bias), which is used to generate a bias magnetic field in the quartz tube, branch ④ is a continuous current / energy discharge branch, and branch ⑤ is a θ-pinch coil with a field inversion configuration, which can actually be regarded as an inductor. The four branches discharge the coil sequentially corresponding to the four stages of the field anti-plasma formation process. During the sequential operation of the first three branches, branch ④ is in a disconnected state. After the work of branches ①~③ is completed, branch ④ is turned on to provide a release path for the energy stored in the θ-pinch coil inductance (branch ⑤).

[0059] Common circuit topologies of branches ① to ③ are as follows: Figure 2As shown, it mainly includes a high-voltage DC source, switch 1, capacitor C1, switch 2, discharge branch (switch 3 + resistor) and θ-pinch coil inductor L. The topology diagram of the FRC circuit system consisting of three branches Main, PI, and Bias is shown in Figure 3 As shown, each branch is configured with its own energy dissipation branch (Crowbar), and the three branches are basically the same in structure, with only differences in electrical parameters and working timing. The direction of the high-voltage DC source of the branch Bias is opposite to that of the power supplies of other branches.

[0060] At present, the power device suitable for the second-order resonance reaction of the θ-pinch coil is a three-gap deuterium-filled metal-ceramic hollow anode structure high-power thyristor. Its appearance structure and wiring diagram are shown in Figure 4 , 5 As shown. The cost of thyratrons is relatively high and has a limited working life. In a power supply, in branches ① to ④, except for switches 11, 21, and 31, which can be considered to use other forms of power switches, 6 hydrogen thyratrons (switch 12, switch 13, switch 22, switch 23, switch 32, and switch 33) are required in total. The system cost is high, and the system volume and weight are large, which is not conducive to the widespread realization of nuclear fusion device power generation.

[0061] Example 1

[0062] To solve the above problems, this embodiment improves the traditional FRC circuit system and proposes an improved branch circuit to enhance its cost and volume advantages. Figure 6 The figure shows the circuit topology of an improved single branch. Compared with the original design, two devices, capacitor C2 and switch 4, are added. Switch 4 is connected in parallel at both ends of capacitor C1, and capacitor C2 is connected in series with the discharge branch and the θ-pinch coil inductor L. The working principle of the improved branch is described as follows.

[0063] (1) The first working stage (preparation stage): see Figure 7 As shown, when switch 1 is turned on, switch 3 and switch 4 are both in the off state. At this time, the high voltage DC source charges capacitor C1.

[0064] (2) The second working stage (pre-ionization stage): see Figure 8 As shown, when capacitor C1 is fully charged, if and only if switch 1, switch 2, and switch 4 are disconnected and switch 3 is turned on, capacitor C1 immediately starts to discharge, and the current flows in the direction of capacitor C1-switch 3-capacitor C2-inductor L-capacitor C1, and capacitor C1 charges capacitor C2 and inductor L.

[0065] At this stage, the circuit satisfies the following equation:

[0066]

[0067] Among them, i c1 is the current flowing out of capacitor C1, i c2 is the current flowing into capacitor C2, i L is the current flowing through the inductance L of the θ-pinch coil, u c1 is the voltage across capacitor C1, u c2 is the voltage across capacitor C2, u L is the voltage across the θ-pinch coil, C1 and C2 are the capacitances of capacitors C1 and C2 respectively, L is the inductance of inductor L, and t represents the discharge time of capacitor C1.

[0068] Since capacitors C1 and C2 are connected in series and resonate with the inductor L in the second order, the following formula exists:

[0069]

[0070] Wherein, L is the equivalent inductance of the θ-pinch coil, C1 is the capacitance of the first capacitor C1, C2 is the capacitance of the second capacitor C2, C res1 is the equivalent capacitance of the first capacitor C1 and the second capacitor C2 connected in series, τ1 is the inductance L and the series capacitor C res1 The time constant of the circuit, f res1 is the inductor L and the series capacitor C res1 The resonant frequency of the circuit.

[0071] The equivalent capacitance of resonance is the series connection of capacitors C1 and C2, and therefore is relatively small, and the resulting oscillation frequency is relatively high, which is suitable for the working requirements of the pre-ionization stage.

[0072] (3) The third working stage (bias stage): see Fig. 9 As shown, in the second working stage, the resonant current gradually decreases to a sufficiently small value, and the charge stored in capacitor C1 is transferred to capacitor C2. At this time, if switch 3 remains on and switch 4 is closed, capacitor C2 will release the charge immediately. At this time, the current flows in the direction of capacitor C2-switch 3-switch 4-inductor L-capacitor C2, and the current direction is reversed.

[0073] At this time, the circuit satisfies the following formula:

[0074]

[0075] Where, L is the equivalent inductance of the θ-pinch coil, C2 is the capacitance of the second capacitor C2, i c2 is the current flowing out of the second capacitor C2, i L is the current flowing through the inductance of the θ-pinch coil, uc2 is the voltage across the second capacitor C2, u L is the voltage across the inductance of the θ-pinch coil, and t represents the discharge time of capacitor C2.

[0076] And the capacitor C2 and the inductor L have second-order resonance, and the following formula also exists:

[0077]

[0078] Where, L is the equivalent inductance of the θ-pinch coil, C2 is the capacitance of the second capacitor C2, C res2 is the equivalent capacitance of the second capacitor C2, τ2 is the inductance L and the series capacitor C res2 The time constant of the circuit, f res2 is the inductor L and the series capacitor C res2 The resonant frequency of the circuit.

[0079] Capacitor C2 reverses the voltage on the inductance L of the θ-pinch coil, so the current through the θ-pinch coil is also reversed. At this time, a second-order resonant circuit is formed by capacitor C2 and the inductance L of the θ-pinch coil. The resonant capacitor only has capacitor C2, so the actual operating frequency is relatively low, and the working characteristics of the circuit are suitable for the working requirements of the paranoid stage.

[0080] By comparing the second working stage and the third working stage, the following comparison results can be obtained:

[0081]

[0082] It can be seen that for common field inversion devices, the operating frequency of the bias stage (Bias) is relatively low, the operating frequencies of the preionization stage (PI) and the field inversion stage (Main) are relatively high, and the field inversion stage (Main) has a higher requirement for di / dt. Therefore, the improved branch circuit topology can replace the traditional branch circuit topology of the bias stage (Bias) and the preionization stage (PI).

[0083] The advantage of this design is that it can save a hydrogen thyratron, reduce the number of cables and connectors, and reduce the size and weight of the system. In short, it is helpful to reduce system costs.

[0084] Example 2

[0085] like Fig.10As shown, the circuit of the present invention is improved and suitable for the θ-pinch field inversion configuration device, the above-mentioned improved branch (Example 1) is used to replace the bias branch (bias) and the pre-ionization branch (PI), and the field inversion branch (Main) continues to use the traditional branch, and its circuit structure is: θ-pinch coil inductance, pre-ionization and bias branch (Bias&PI) and field inversion branch (Main).

[0086] Wherein, the pre-ionization and bias branch includes a first high-voltage DC source U1, a first switch K1 and a first capacitor C1 connected in series with the first high-voltage DC source U1, a second switch K2 connected in parallel with the first capacitor C1, a third switch K3 and a second capacitor C2 connected in series with the second switch K2, and a first discharge branch. The second switch K2 and the second capacitor C2 are newly added structures, and the first capacitor C1, the third switch K3, the second capacitor C2 and the θ-pinch coil inductor are connected in series to form a loop to achieve pre-ionization, see the second working stage (2). The second switch K2, the third switch K3, the second capacitor C2 and the θ-pinch coil inductor are connected in series to form a loop to achieve bias, see the third working stage (3). The first discharge branch is connected in series with the θ-pinch coil inductor to form a discharge loop for the θ-pinch coil inductor to release charge.

[0087] The field reversal branch includes a second high-voltage DC source U2, a fourth switch K4 connected in series with the second high-voltage DC source U2, a third capacitor C3 connected in parallel with the second high-voltage DC source U2 and the fourth switch K4, a fifth switch K5 connected in series with the third capacitor C3, and a second discharge branch. The third capacitor C3, the fifth switch K5 and the θ-pinch coil inductor are connected in series to form a loop, and the second discharge branch is connected in series with the θ-pinch coil inductor to form a discharge loop.

[0088] In the improved circuit, the functions of the pre-ionization branch and the bias branch are realized through one branch, which reduces the use of components, especially the demand for hydrogen thyratron switches. In the original FRC circuit system, 6 hydrogen thyratron switches are required, while the solution of the present invention only requires 4 (K3, K5 and the control switches of the two discharge circuits). While realizing the work of the Bias and PI stages, the pre-ionization and bias branches share the same cables, connectors, chargers, cooling systems and system cabinets. Compared with the previous two branches (Bias and PI), the structure is more compact, which greatly reduces the system cost and volume.

[0089] The difference from the traditional FRC circuit also includes that the voltage output directions of the first high-voltage DC source U1 and the second high-voltage DC source U2 are the same. Since the current is reversed in the third working stage (3), there is no need to set the voltage direction of the Bias branch to be different from that of other branches.

[0090] The working principle of the preionization and bias branches is the same as that of the single branch in Example 2:

[0091] (1) Preparation stage: the first switch K1 is turned on, the second switch K2, the third switch K3 and the first discharge branch (the control switch is disconnected) are turned off, and the first high-voltage DC source U1 charges the first capacitor C1.

[0092] (2) Pre-ionization stage: the third switch K3 is turned on, the first switch K1, the second switch K2 and the first discharge branch are turned off, and the capacitor C1 immediately starts to discharge. The current releases the charge along the first capacitor C1-third switch K3-second capacitor C2-θ-pinch coil inductance-first capacitor C1, forming a second-order resonant model, in which C1 and C2 are in series.

[0093] (3) Bias stage: In the pre-ionization stage, when the resonant current gradually decreases to a sufficiently small value, the charge stored in the first capacitor C1 is transferred to the second capacitor C2. At this time, the first switch K1, the second switch K2 and the first discharge branch remain disconnected, the third switch K3 is still turned on and the second switch K2 is closed. The second capacitor releases the charge immediately. At this time, the current flows along the second capacitor C2-third switch K3-second switch K2-θ-pinch coil inductance-second capacitor C2. The current direction is reversed compared to the pre-ionization stage.

[0094] The circuit parameters in the pre-ionization stage refer to the above formula groups (1) and (2), and the circuit parameters in the bias stage refer to the above formula groups (3) and (4).

[0095] The discharge circuit adopts a traditional setting, including a control switch and a resistor in series, and the control switch adopts a hydrogen thyratron.

[0096] In order to further save costs, the first discharge branch and the second discharge branch are combined into one, and the pre-ionization and bias branch and the field reversal branch share a discharge circuit. The circuit diagram is shown in FIG. Fig.11 As shown, the Crowbar circuits of the preionization and bias branches and the field inversion branches are cancelled, and the Crowbar circuits are unified and installed near the θ-pinch coil.

[0097] While maintaining the same function and performance, one Crowbar circuit can be reduced, further reducing system cost, weight and volume.

[0098] In one embodiment, the second switch K2 is further connected in series with the inductor L1. The second switch K2, the inductor L1, the third switch K3, the second capacitor and the θ-pinch coil inductor L are connected in series to form a loop. The circuit diagram is as follows: Fig.12 shown.

[0099] Inductor L1 is connected in series with the inductor L of the θ-pinch coil. The actual inductance is the sum of L1 and L. This actual inductance resonates with capacitor C2 in the second order, and the formula can be obtained:

[0100] L real =L1+L

[0101]

[0102] Among them, L real is the actual inductance value, L1 is the inductance value of the inductor L1, L is the inductance value of the θ-pinch coil inductor L, τ real is the inductance L real The time constant of the circuit where the series capacitor C2 is located, f real is the inductance L real And the resonant frequency of the circuit where the series capacitor C2 is located.

[0103] Example 3

[0104] This embodiment provides a device suitable for forming a field inversion shape by a θ-pinch, including a circuit suitable for forming a field inversion shape by a θ-pinch according to any of the above-mentioned embodiments of the present invention.

[0105] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A circuit suitable for forming a field inversion configuration device of θ-pinch, characterized in that: include: θ-pinch coil inductance; The pre-ionization and bias branch includes a first high-voltage DC source U1, a first switch K1 and a first capacitor C1 connected in series with the first high-voltage DC source U1, a second switch K2 connected in parallel with the first capacitor C1, a third switch K3 and a second capacitor C2 connected in series with the second switch K2, and a first discharge branch; the first capacitor C1, the third switch K3, the second capacitor C2 and the θ-pinch coil inductor are connected in series to form a loop to achieve pre-ionization, the second switch K2, the third switch K3, the second capacitor C2 and the θ-pinch coil inductor are connected in series to form a loop to achieve bias, and the first discharge branch is connected in series with the θ-pinch coil inductor to form a discharge loop; The field reversal branch includes a second high-voltage DC source U2, a fourth switch K4 connected in series with the second high-voltage DC source U2, a third capacitor C3 connected in parallel with the second high-voltage DC source U2 and the fourth switch K4, a fifth switch K5 connected in series with the third capacitor C3, and a second discharge branch. The third capacitor C3, the fifth switch K5 and the θ-pinch coil inductor are connected in series to form a loop, and the second discharge branch is connected in series with the θ-pinch coil inductor to form a discharge loop.

2. The circuit for forming a field inversion device for θ-pinch according to claim 1, characterized in that: The first discharge branch and the second discharge branch are both composed of a resistor and a control switch connected in series, and are used for the θ-pinch coil inductance to release charge.

3. The circuit for forming a field inversion device for θ-pinch according to claim 2, characterized in that: The third switch, the fifth switch, and the control switches of the first discharge branch and the second discharge branch are hydrogen thyristors.

4. The circuit for forming a field inversion device for θ-pinch according to claim 2, characterized in that: The pre-ionization and bias branch and the field reversal branch share a discharge circuit, and the shared discharge circuit is formed by merging the first discharge branch and the second discharge branch and connecting them in series with the θ-pinch coil inductance.

5. The circuit suitable for forming a field inversion configuration device of θ-pinch according to any one of claims 1 to 4, characterized in that: The second switch K2 is also connected in series with an inductor L1. The second switch K2, the inductor L1, the third switch K3, the second capacitor and the θ-pinch coil inductor L are connected in series to form a loop.

6. The circuit for forming a field inversion device for θ-pinch according to claim 1, characterized in that: The voltage output directions of the first high-voltage DC source U1 and the second high-voltage DC source U2 are the same.

7. The circuit for forming a field inversion device for θ-pinch according to claim 1, characterized in that: The pre-ionization and bias branch realizes pre-ionization and bias through switch timing control, including: Preparation stage: the first switch K1 is turned on, the second switch K2, the third switch K3 and the first discharge branch are turned off, and the first high-voltage DC source U1 charges the first capacitor C1; Pre-ionization stage: the third switch K3 is turned on, the first switch K1, the second switch K2 and the first discharge branch are turned off, at this time the capacitor C1 immediately starts to discharge, and the current releases the charge along the first capacitor C1-third switch K3-second capacitor C2-θ-pinch coil inductance-first capacitor C1, forming a second-order resonant model, in which C1 and C2 are in series; Bias stage: In the pre-ionization stage working state, when the resonant current gradually decreases to a sufficiently small value, the charge stored in the first capacitor C1 is transferred to the second capacitor C2. At this time, the first switch K1, the second switch K2 and the first discharge branch remain disconnected, the third switch K3 is still turned on and the second switch K2 is closed, and the second capacitor releases the charge immediately. At this time, the current flows along the second capacitor C2-third switch K3-second switch K2-θ-pinch coil inductance-second capacitor C2, and the current direction is reversed compared to the pre-ionization stage.

8. The circuit for forming a field inversion device for θ-pinch according to claim 7, characterized in that: In the pre-ionization stage, the first capacitor C1 and the second capacitor C2 resonate with the inductance of the θ-pinch coil in the second order, and the circuit satisfies the following resonance formula: in c1 =in c2 +in L Among them, i c1 is the current flowing out of the first capacitor C1, i c2 is the current flowing into the second capacitor C2, i L is the current flowing through the inductance of the θ-pinch coil, u c1 is the voltage across the first capacitor C1, u c2 is the voltage across the second capacitor C2, u L is the voltage across the inductance of the θ-pinch coil, and t is the time; Since the first capacitor C1 and the second capacitor C2 are connected in series and resonate with the θ-pinch coil inductance in the second order, the following formula also exists: Wherein, L is the equivalent inductance of the θ-pinch coil, C1 is the capacitance of the first capacitor C1, C2 is the capacitance of the second capacitor C2, C res1 is the equivalent capacitance of the first capacitor C1 and the second capacitor C2 connected in series, τ1 is the inductance L and the series capacitor C res1 The time constant of the circuit, f res1 is the inductor L and the series capacitor C res1 The resonant frequency of the circuit.

9. The circuit for forming a field inversion device for θ-pinch according to claim 7, characterized in that: In the bias stage, the second capacitor C2 and the inductance of the θ-pinch coil undergo second-order resonance, and the circuit satisfies the following resonance formula: -in c2 =-in L Where, L is the equivalent inductance of the θ-pinch coil, C2 is the capacitance of the second capacitor C2, i c2 is the current flowing out of the second capacitor C2, i L is the current flowing through the inductance of the θ-pinch coil, u c2 is the voltage across the second capacitor C2, u L is the voltage across the inductance of the θ-pinch coil, and t is the time; Since the second capacitor C2 and the θ-pinch coil inductor have a second-order resonance, the following formula also exists: C res2 =C2 Where, L is the equivalent inductance of the θ-pinch coil, C2 is the capacitance of the second capacitor C2, C res2 is the equivalent capacitance of the second capacitor C2, τ2 is the inductance L and the series capacitor C res2 The time constant of the circuit, f res2 is the inductor L and the series capacitor C res2 The resonant frequency of the circuit.

10. A device suitable for forming a field inversion configuration in θ-pinch, characterized in that: A circuit suitable for forming a field inversion configuration device of θ-pinch comprising the circuit described in any one of claims 1 to 9.

Images