A compact eight-channel pulse solenoid valve power supply and its control method

Abstract

This invention relates to the field of pulse power supply technology for electromagnetic valves, and particularly to a compact-loop eight-channel pulse electromagnetic valve power supply and its control method. The technical solution includes a pre-stage AC-DC rectifier network, a DC-DC charging network, an energy storage capacitor, eight parallel-connected pulse discharge modules, and a main control unit. The input of the pre-stage AC-DC rectifier network is connected to an AC power source to convert AC to DC. The input of the DC-DC charging network is connected to the output of the AC-DC rectifier network to provide a controllable DC charging voltage. This invention, through eight-channel parallel synchronous pulse discharge, wide-range adjustable output parameters, microsecond-level fast switching response, and modular redundancy design, provides a highly synchronized, highly flexible, highly reliable, and low-cost pulse power supply solution for electromagnetic valves in compact-loop devices, effectively ensuring the uniformity and stability of plasma within the compact loop.

Description

Technical Field

[0001] This invention relates to the field of pulse power supply technology for electromagnetic valves, and in particular to a compact eight-channel pulse electromagnetic valve power supply and its control method. Background Technology

[0002] Controlled nuclear fusion, as an important direction for the development of future clean energy, has made significant progress in recent years. Among them, the compact torus (CT) device is considered one of the promising technologies for the first commercialization of fusion energy due to its relatively simple structure, low construction cost, and strong engineering feasibility. In the plasma formation, acceleration, compression, and injection processes, the compact torus device heavily relies on electromagnetic valves to achieve rapid, precise, and repeatable injection of fuel gas to ensure the density, uniformity, and stability of the plasma.

[0003] As a key actuator in a compact ring apparatus, the electromagnetic valve faces stringent requirements for its power supply: First, the power supply must provide a high voltage of several hundred volts (typically 300V–600V) to drive the electromagnetic valve to open rapidly; second, the pulse width must be adjustable in the microsecond range (e.g., 0–500μs) to meet the requirements of short pulses and large intake volumes; third, it must have a stable repetition frequency capability (typically 0–50Hz) to support multi-pulse repeated injection experiments; fourth, and more critically, compact ring apparatuses typically employ a multi-channel (e.g., eight-channel) electromagnetic valve surround layout, requiring all channels to open synchronously, thereby ensuring uniform distribution of the injected fuel gas in the circumferential and annular directions, avoiding plasma asymmetry, instability, or even rupture caused by asynchronous intake.

[0004] Currently, pulse power supply solutions for solenoid valves mainly include: circuits based on capacitor energy storage and thyristor or IGBT single-transistor discharge, and topologies employing a high-voltage DC bus and a single-channel switch. However, existing power supply solutions have the following technical drawbacks when applied to compact eight-channel ring scenarios:

[0005] Poor synchronization of multiple channels: Traditional solutions usually use a single power supply to drive multiple electromagnetic valves in a time-sharing manner, or use multiple independent power supplies to drive them separately. It is difficult to achieve time synchronization between channels at the nanosecond to microsecond level, resulting in asynchronous gas injection and affecting the uniformity of plasma density distribution.

[0006] Limited output voltage and pulse width adjustment range: Existing pulse power supplies are mostly designed with fixed parameters or narrow adjustable range, which cannot flexibly change the pulse voltage amplitude (300V~600V), pulse width (0~500μs) and frequency (0~50Hz) on the same device. When the experimental parameters are adjusted, the power supply needs to be replaced or redesigned, resulting in high R&D costs and long development cycles.

[0007] Insufficient response speed and turn-off capability: Traditional IGBTs or mechanical switches have limited switching speeds, making it difficult to complete the turn-on and turn-off within microseconds. Furthermore, the inductor energy storage freewheeling path after turn-off is imperfect, which can easily generate voltage spikes or current tails, affecting the steepness and repeatability of the pulse waveform.

[0008] Low reliability of single-power centralized power supply: Using a single high-power switching module to drive eight solenoid valves simultaneously, once the switching device fails, the entire intake system will be paralyzed, and electromagnetic compatibility issues are prominent.

[0009] Therefore, this application proposes a compact eight-channel pulse solenoid valve power supply and its control method. Summary of the Invention

[0010] The purpose of this invention is to address the problems of poor multi-channel synchronization and limited output voltage and pulse width adjustment range in existing power supply solutions when applied to compact eight-channel scenarios. This invention proposes a compact eight-channel pulse solenoid valve power supply and its control method.

[0011] In a first aspect, this application provides a compact eight-channel pulse solenoid valve power supply, comprising:

[0012] The front-stage AC-DC rectifier network has its input connected to an AC power source to convert AC power into DC power.

[0013] A DC-DC charging network, the input of which is connected to the output of the AC-DC rectifier network, is used to provide a controllable DC charging voltage;

[0014] An energy storage capacitor, whose input terminal is connected to the output terminal of the DC-DC charging network, is used to store the energy required for pulse discharge.

[0015] Eight pulse discharge modules are connected in parallel. The input terminal of each pulse discharge module is connected to the output terminal of the energy storage capacitor, and the output terminal of each pulse discharge module is used to connect to a corresponding solenoid valve.

[0016] The main control unit is connected to the control terminal of the DC-DC charging network and each pulse discharge module, respectively. It is used to send synchronous trigger signals to each pulse discharge module to control all pulse discharge modules to perform pulse discharge synchronously. By adjusting the parameters of the trigger signal, the amplitude, pulse width and frequency of the output voltage are changed, thereby realizing flexible control of the intake parameters of the electromagnetic valve.

[0017] Optionally, the pulse discharge module is based on a high-side drive circuit topology and includes a high-speed switching device, a freewheeling diode, a filter capacitor, and a filter inductor.

[0018] Optionally, the high-speed switching device is a wide-bandgap semiconductor device.

[0019] Optionally, the wide bandgap semiconductor device is a silicon carbide MOSFET, and the pulse discharge module includes an IGBT with a diode and a freewheeling diode.

[0020] Optionally, the DC-DC charging network is a phase-shifted full-bridge closed-loop circuit, which includes a transformer, a resonant inductor, a DC blocking capacitor, an output filter inductor, and an output filter capacitor. It is configured to control the switching on and off of the switching transistors in the phase-shifted full-bridge circuit by sampling the output voltage and output current in real time and calculating the phase shift of the PWM signal in combination with a proportional-integral control algorithm, so as to charge the energy storage capacitor at constant voltage or constant current.

[0021] Optionally, the power supply outputs a pulse voltage range of 300V to 600V, a pulse width range of 0 to 500μs, and a frequency range of 0 to 50Hz.

[0022] Optionally, the eight pulse discharge modules are identical in circuit topology and electrical parameters, and simultaneously output pulse voltages under the control of the synchronous trigger signal sent by the main control unit, so that the eight solenoid valves open synchronously.

[0023] Secondly, this application provides a control method for a compact ring eight-channel pulse solenoid valve power supply based on the first aspect, comprising the following steps:

[0024] S1. The three-phase alternating current is rectified into direct current through the AC-DC rectifier network;

[0025] S2. Charge the energy storage capacitor to a preset voltage value through the DC-DC charging network;

[0026] S3. The main control unit simultaneously sends a synchronous trigger signal to all parallel pulse discharge modules;

[0027] S4. Each pulse discharge module responds to the synchronous trigger signal and synchronously turns on its internal high-speed switching device, outputting pulse voltage to the connected solenoid valve, so that all solenoid valves open simultaneously.

[0028] Optionally, the synchronous trigger signal is a pulse signal with adjustable pulse width; after the pulse discharge ends, the synchronous trigger signal returns to zero, the high-speed switching device is turned off, and the filter inductor in each pulse discharge module continues to flow through the corresponding freewheeling diode until the inductor current drops to zero.

[0029] Optionally, the DC-DC charging network in step S2 adopts a phase-shifted full-bridge closed-loop circuit. By sampling the output voltage and output current in real time, substituting the sampling results into the proportional gain and integral gain respectively, the phase shift of the PWM signal is calculated in real time and the PWM wave is output. The switching transistor in the phase-shifted full-bridge circuit is controlled according to the PWM wave to charge the energy storage capacitor.

[0030] After a pulse discharge is completed and the follow-through ends, wait for the plasma concentration in the compact ring to decrease to a set threshold, and then the main control unit sends a synchronization trigger signal again to repeat steps S3 and S4 to achieve periodic pulse discharge.

[0031] Compared with the prior art, this application includes at least one of the following beneficial technical effects:

[0032] The eight pulse discharge modules discharge simultaneously under the unified synchronous trigger signal control of the main control unit, ensuring that the eight electromagnetic valves open synchronously, so that the plasma density distribution in the compact ring is uniform and avoids plasma instability or rupture caused by asynchronous air intake.

[0033] The power supply output voltage can be flexibly adjusted within the range of 300V to 600V, pulse width 0 to 500μs, and frequency 0 to 50Hz. Different experimental requirements can be adapted simply by changing the trigger signal parameters, without the need to redesign or replace the power supply.

[0034] High-speed switching devices such as wide-bandgap semiconductors (e.g., SiC MOSFETs) are used in conjunction with freewheeling diodes to form a complete freewheeling circuit, achieving steep pulse rise and fall edges to meet the requirements of short pulse and large air intake.

[0035] The eight pulse discharge modules are connected in parallel with identical electrical parameters. The failure of a single module does not affect the operation of the other channels, making the system highly fault-tolerant. At the same time, the modular design facilitates expansion and maintenance.

[0036] The adjustable parameter range covers a variety of experimental conditions, avoiding the need to repeatedly design circuit topologies and control strategies for different parameter requirements, significantly shortening the R&D cycle and reducing R&D and customization costs.

[0037] In summary, this invention provides a highly synchronized, flexible, reliable, and low-cost pulse power supply solution for the electromagnetic valve of the compact ring device through eight-channel parallel synchronous pulse discharge, wide-range adjustable output parameters, microsecond-level fast switching response, and modular redundancy design, effectively ensuring the uniformity and stability of plasma within the compact ring. Attached Figure Description

[0038] Figure 1 Circuit topology diagram for a compact eight-channel pulse solenoid valve power supply design;

[0039] Figure 2 A reference circuit for a rectifier network section provided in an embodiment of this application;

[0040] Figure 3 A reference circuit for a charging network portion provided in an embodiment of this application;

[0041] Figure 4 A reference circuit for a discharge module portion provided in an embodiment of this application;

[0042] Figure 5 A waveform diagram of the output voltage of a 200V charging network provided in an embodiment of this application;

[0043] Figure 6 The diagram shows a pulse voltage waveform of a discharge module outputting 600V, as provided in an embodiment of this application. Detailed Implementation

[0044] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0045] Example 1

[0046] This embodiment provides a compact eight-channel pulse solenoid valve power supply, the circuit topology of which is shown below. Figure 1 As shown, it includes: a rectifier network, a charging network, a pulse discharge module, and a control unit.

[0047] I. Rectifier Network Design

[0048] refer to Figure 2 The rectifier network uses an AC-DC rectifier bridge, with its input connected to a 220V three-phase AC power supply. This rectifier network first rectifies the three-phase AC power into DC power to supply power to the charging network.

[0049] In this embodiment, the three-phase line voltage The voltage is 380V, the phase voltage is 220V, and the frequency is... 50Hz, power For 5000W, efficiency It is 90%. Maximum DC voltage ripple after uncontrolled rectification and filtering. Calculate according to formula (1):

[0050]

[0051] Minimum DC voltage after uncontrolled rectification Calculate according to formula (2):

[0052]

[0053] The single-cycle input filter capacitor provides energy. Calculate according to formula (3):

[0054]

[0055] Minimum filter capacitor Calculate according to formula (4):

[0056]

[0057] Taking a margin of 1.2, the input filter capacitor is obtained. .

[0058] II. Charging Network Design

[0059] refer to Figure 3 The charging network adopts a phase-shifted full-bridge closed-loop circuit topology, including a transformer, resonant inductor, DC blocking capacitor, output filter inductor, and output filter capacitor.

[0060] (1) Transformer turns ratio design: Input voltage Take 500V, output voltage Take 200V, and assume maximum duty cycle loss. The maximum effective duty cycle is 0.2. If it is 0.8, then the transformer turns ratio is... Calculate according to formula (5):

[0061]

[0062] (2) Resonant inductor design: Assuming a 30% load requires ZVS and a full-load output current The primary current is 25A. Calculate according to formula (6):

[0063]

[0064] Parasitic capacitance of switching transistor Take 120pF as the parasitic capacitance of the transformer primary winding. If we set it to 0, then the resonant inductance... The lower limit is calculated according to formula (7):

[0065]

[0066] The maximum duty cycle loss is 0.2, that is... Switching frequency If the frequency is 25kHz, then the resonant inductance The upper limit is calculated according to formula (8):

[0067]

[0068] Ultimately, the resonant inductance is set to a value of .

[0069] (3) DC blocking capacitor design: To avoid DC components, a DC blocking capacitor is connected in series on the primary side of the transformer. The peak-to-peak voltage across the capacitor is less than 10% of the input voltage. Calculate according to formula (9):

[0070]

[0071] Select a 4uF DC blocking capacitor.

[0072] (4) Output filter inductor design: take the inductor ripple for Assume the DC component of the inductance. The diode voltage drop is 1.5V. If it is 0.5V, then the output filter inductor Calculate according to formula (10):

[0073]

[0074] Choose an output filter inductance of 1.5mH.

[0075] (5) Output filter capacitor design: Assume the maximum current on the capacitor The current is 35A, and the discharge time of the subsequent stage is... The maximum output voltage ripple is 300μs. If it is 1V, then the output filter capacitor Calculate according to formula (11):

[0076]

[0077] Select an output filter capacitor of 10.5mF.

[0078] The actual circuit also includes drive and power supply components, as well as four IGBT transistors with diodes and four freewheeling diodes.

[0079] III. Pulse Discharge Module Design

[0080] refer to Figure 4 The pulse discharge module is based on a high-side drive circuit and includes a MOSFET with a diode (high-speed switching device), a freewheeling diode, a filter capacitor, and an output filter inductor. In this embodiment, the filter capacitor is 340μF and the output filter inductor is 77mH.

[0081] The eight pulse discharge modules are identical in structure and electrical parameters. The input terminals of each module are connected in parallel, and each module's output terminal is connected to a solenoid valve. The eight pulse discharge modules discharge synchronously to control the simultaneous opening and closing of the solenoid valves, thereby ensuring a uniform distribution of plasma within the compact ring.

[0082] High-speed switching devices can be wide-bandgap semiconductor devices, such as SiC MOSFETs. As an alternative, the pulse discharge module can also be constructed using IGBTs with diodes and freewheeling diodes.

[0083] IV. Control Unit Design: The control unit is based on a high-performance digital signal processor (DSP) (such as TI's TMS320F28335). This DSP controls multiple downstream pulse discharge modules to synchronously output pulse current through its PWM output pin, and simultaneously controls the upstream AC-DC charging network to charge the energy storage capacitor.

[0084] V. Working Principle and Process

[0085] The operation of the compact ring eight-channel pulse solenoid valve power supply in this embodiment includes the following stages:

[0086] (1) Charging stage: The control unit outputs control commands to start the front-end DC-DC charging network, which charges the energy storage capacitors of the eight discharge modules in constant current mode until their voltage reaches the preset value (e.g., 600V). The DSP monitors the charging current and voltage at the same time, calculates the phase shift of the PWM in real time through proportional gain and integral gain, and outputs the PWM wave to control the switching transistors to achieve phase-shifted full-bridge closed-loop control.

[0087] (2) Standby stage: After charging is completed, the output voltage remains at a preset stable state and the system enters standby state.

[0088] (3) Discharge stage: When a pulse voltage is required, the control unit simultaneously sends a fully synchronized PWM pulse as a trigger signal to the local drive circuit of the eight discharge modules. At this time, the switching transistor in the pulse discharge module is turned on, providing a pulse voltage to the load solenoid valve. The DSP controls the switching transistor to achieve pulse discharge of the discharge module. The pulse width is equal to the on time of the switching transistor.

[0089] (4) Turn-off and freewheeling phase: When the set pulse width ends, the synchronous trigger signal returns to zero, and the switching transistor turns off. The remaining energy in each output filter inductor is freewheeled through its corresponding freewheeling diode to form a loop until the inductor current drops to zero, completing a complete pulse cycle.

[0090] VI. Output Parameters and Effects

[0091] In this embodiment, the output voltage is 300–600V, the pulse width is 0–500μs, and the frequency is between 0–50Hz, providing a wide adjustment range. During fusion experiments, it is only necessary to adjust the input trigger signal of the switching tube in real time according to the actual parameters of the plasma within the compact loop, thereby changing different output parameters to achieve flexible control of the intake parameters.

[0092] Eight pulse discharge modules are connected in parallel and synchronously output instantaneous pulse voltages to eight solenoid valves, ensuring uniform plasma distribution within a certain concentration range within the compact loop. The adjustable range avoids redundant design and verification of circuit topology and control strategies, shortening development time and reducing R&D and customization costs. Under the synchronous trigger signal control of the central control unit, all pulse discharge modules can operate synchronously, jointly providing pulse voltages to the solenoid valves, ensuring that all eight solenoid valves can simultaneously enter the open state.

[0093] refer to Figure 5 The charging network can stably output a DC voltage of 200V at a frequency of 25kHz (as an example waveform). Reference Figure 6 The discharge module can output a 600V pulse voltage with steep rising and falling edges.

[0094] It should be noted that after the pulse discharge ends and the follow current is completed, the control unit will input a trigger signal to the switch tube again after waiting for the plasma concentration in the compact ring to drop to the required level, repeating the synchronous discharge process of the above discharge module to achieve periodic pulse output.

[0095] This invention provides a compact-loop eight-channel pulsed solenoid valve power supply. It employs a modular topology architecture consisting of pre-stage AC-DC rectification, DC-DC phase-shifted full-bridge closed-loop charging, and eight parallel high-side drive pulse discharge modules. A strictly synchronized trigger signal is issued from a single central control unit, enabling eight pulse discharge modules with identical electrical parameters to simultaneously output high-voltage, short-pulse-width, steep-edge pulse currents to their respective connected solenoid valves. This fundamentally solves the technical problem of uneven plasma distribution caused by asynchronous gas injection in multiple channels. Furthermore, by adjusting the amplitude, width, and frequency of the trigger signal in real time, the power supply can flexibly output DC pulse voltage within a wide range of 300V–600V, pulse width 0–500μs, and frequency 0–50Hz. This allows for adaptation to different experimental conditions without hardware replacement or redesign, significantly shortening the development cycle of the compact-loop device and reducing customization costs. In addition, SiC is used in the pulse discharge modules. A complete freewheeling circuit composed of MOSFETs and other wide-bandgap semiconductor devices and freewheeling diodes ensures microsecond-level rapid turn-on and turn-off capabilities. The pulse waveform features steep rising and falling edges. Combined with optimized parameter design of the energy storage capacitor and filter inductor, stable and repeatable pulse output is achieved. The eight parallel modules are redundant, meaning that the failure of one module does not affect the operation of other channels, significantly improving the system's reliability and fault tolerance. This invention provides a dedicated pulsed electromagnetic valve power supply for compact ring devices, offering high synchronization, high flexibility, high reliability, and fast response, effectively ensuring the uniformity of plasma density distribution and the stability of fusion experiments.

[0096] The above specific embodiments are merely several optional embodiments of the present invention. Based on the technical solutions of the present invention and the relevant teachings of the above embodiments, those skilled in the art can make various alternative improvements and combinations to the above specific embodiments.

Claims

1. A compact eight-channel pulse solenoid valve power supply, characterized in that, include: The front-end AC-DC rectifier network has its input connected to an AC power source to convert AC power into DC power. A DC-DC charging network, the input of which is connected to the output of the AC-DC rectifier network, is used to provide a controllable DC charging voltage; An energy storage capacitor, whose input terminal is connected to the output terminal of the DC-DC charging network, is used to store the energy required for pulse discharge. Eight pulse discharge modules are connected in parallel. The input terminal of each pulse discharge module is connected to the output terminal of the energy storage capacitor, and the output terminal of each pulse discharge module is used to connect to a corresponding solenoid valve. The main control unit is connected to the control terminal of the DC-DC charging network and each pulse discharge module, respectively. It is used to send synchronous trigger signals to each pulse discharge module to control all pulse discharge modules to perform pulse discharge synchronously. By adjusting the parameters of the trigger signal, the amplitude, pulse width and frequency of the output voltage are changed, thereby realizing flexible control of the intake parameters of the electromagnetic valve.

2. The compact ring eight-channel pulse solenoid valve power supply according to claim 1, characterized in that, The pulse discharge module is based on a high-side drive circuit topology and includes high-speed switching devices, freewheeling diodes, filter capacitors, and filter inductors.

3. The compact eight-channel pulse solenoid valve power supply according to claim 2, characterized in that, The high-speed switching device is a wide bandgap semiconductor device.

4. A compact eight-channel pulse solenoid valve power supply according to claim 3, characterized in that, The wide bandgap semiconductor device is a silicon carbide MOSFET, and the pulse discharge module includes an IGBT with a diode and a freewheeling diode.

5. A compact ring eight-channel pulse solenoid valve power supply according to claim 1, characterized in that, The DC-DC charging network is a phase-shifted full-bridge closed-loop circuit, which includes a transformer, a resonant inductor, a DC blocking capacitor, an output filter inductor, and an output filter capacitor. It is configured to control the switching on and off of the switching transistors in the phase-shifted full-bridge circuit by sampling the output voltage and output current in real time and calculating the phase shift of the PWM signal using a proportional-integral control algorithm, so as to charge the energy storage capacitor at constant voltage or constant current.

6. The compact ring eight-channel pulse solenoid valve power supply according to claim 1, characterized in that, The power supply outputs a pulse voltage ranging from 300V to 600V, a pulse width ranging from 0 to 500μs, and a frequency ranging from 0 to 50Hz.

7. A compact ring eight-channel pulse solenoid valve power supply according to claim 1, characterized in that, The eight pulse discharge modules are identical in circuit topology and electrical parameters, and simultaneously output pulse voltages under the control of the synchronous trigger signal sent by the main control unit, so that the eight solenoid valves open synchronously.

8. A control method for a compact ring eight-channel pulse solenoid valve power supply based on any one of claims 1 to 7, characterized in that, Includes the following steps: S1. The three-phase alternating current is rectified into direct current through the AC-DC rectifier network; S2. Charge the energy storage capacitor to a preset voltage value through the DC-DC charging network; S3. The main control unit simultaneously sends a synchronous trigger signal to all parallel pulse discharge modules; S4. Each pulse discharge module responds to the synchronous trigger signal and synchronously turns on its internal high-speed switching device, outputting pulse voltage to the connected solenoid valve, so that all solenoid valves open simultaneously.

9. The control method for a compact ring eight-channel pulse solenoid valve power supply according to claim 8, characterized in that, The synchronous trigger signal is a pulse signal with adjustable pulse width. After the pulse discharge ends, the synchronous trigger signal returns to zero, the high-speed switching device is turned off, and the filter inductor in each pulse discharge module continues to flow through the corresponding freewheeling diode until the inductor current drops to zero.

10. The control method of a compact ring eight-channel pulse electromagnetic valve power supply according to claim 8, wherein the DC-DC charging network in step S2 adopts a phase-shifted full-bridge closed-loop circuit, and the output voltage and output current are sampled in real time, the sampling results are substituted into the proportional gain and integral gain respectively, the phase shift of the PWM signal is calculated in real time and the PWM wave is output, and the switching transistor in the phase-shifted full-bridge circuit is controlled according to the PWM wave to charge the energy storage capacitor; After a pulse discharge is completed and the follow-through ends, wait for the plasma concentration in the compact ring to decrease to a set threshold, and then the main control unit sends a synchronization trigger signal again to repeat steps S3 and S4 for periodic pulse discharge.

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