A high-voltage, high-current light-controlled solid-state switch assembly based on double isolation

Abstract

This invention discloses a high-voltage, high-current optically controlled solid-state switch assembly based on dual isolation, relating to particle accelerators, pulsed power, and power electronics. It includes: a synchronous triggering system, isolated laser driving units, a series group of laser diodes, and optically controlled multi-gate thyristors. An external trigger signal first enters the synchronous triggering system, converting the initial external trigger signal into multiple nanosecond-level synchronous weak light trigger signals. These weak light trigger signals are losslessly transmitted to each isolated laser driving unit. Upon receiving the weak light trigger signal, the isolated laser driving unit amplifies the energy through an internal high-speed power semiconductor switch, outputting an electrical pulse. The electrical pulse is transmitted via a coaxial transmission line to the series group of laser diodes, which converts the electrical pulse into a trigger light spot. The trigger light spot matches the optical window of the optically controlled multi-gate thyristor, completing the photoelectric conversion and driving the thyristor to conduct. A static voltage equalization and protection system is connected in parallel across each optically controlled multi-gate thyristor.

Description

Technical Field

[0001] This invention relates to the fields of particle accelerators, pulsed power, and power electronics, and particularly to a high-voltage, high-current optically controlled solid-state switch assembly based on dual isolation. Background Technology

[0002] In the field of pulsed power, achieving high peak power, fast turn-on speed, and DC charging capability in solid-state switches presents a key technological challenge. While traditional gas switches offer high power capacity, they suffer from short lifespans and significant timing jitter. Existing solid-state switches, such as thyristors and IGBTs, face a series of complex technical challenges when improving voltage withstand levels through series connection, including trigger synchronization, dynamic voltage equalization, and high-voltage isolated power supply. Particularly for optically controlled thyristors, the trigger synchronization accuracy and the stability of the isolated drive power supply when multiple thyristors are connected in series directly determine the reliability and performance ceiling of the entire system. Therefore, a highly integrated and reliable multi-stage optically controlled switch system solution is urgently needed. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a high-voltage, high-current optically controlled solid-state switch assembly based on dual isolation. Through innovative system architecture and circuit design, high-voltage series operation of multiple optically controlled multi-gate thyristors is achieved, significantly improving the voltage and current ratings of the solid-state switch.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A high-voltage, high-current optically controlled solid-state switch assembly based on dual isolation includes: a synchronous triggering system, an optical fiber transmission line, an isolated laser driving unit, a coaxial transmission line, a laser diode series group, an optically controlled multi-gate thyristor, a low-voltage power supply system, a DC-AC inverter system, a magnetic ring isolated power supply system, and a static voltage equalization and protection system.

[0006] The external trigger signal first enters the synchronous triggering system, which converts the initial external trigger signal into multiple nanosecond-level synchronous weak light trigger signals. The weak light trigger signals are then transmitted losslessly to the isolated laser drive units on each high-voltage side via fiber optic transmission lines. After receiving the weak light trigger signals, the isolated laser drive units amplify the energy through internal high-speed power semiconductor switches and output electrical pulses. The electrical pulses are transmitted to the laser diode series group via coaxial transmission lines. The laser diode series group converts the electrical pulses into trigger light spots. The trigger light spots are matched with the optical windows of the optically controlled multi-gate thyristors to complete the photoelectric conversion and drive the thyristors to conduct. The static voltage equalization and protection system is connected in parallel across each optically controlled multi-gate thyristor. The low-voltage power supply system supplies power to the synchronous triggering system, and at the same time, the DC-AC inverter system supplies power to the magnetic ring isolated power supply system.

[0007] Compared with the prior art, the present invention has the following significant advantages:

[0008] 1. High voltage and high current rating: By using the series connection technology of optically controlled multi-gate thyristors, the operating voltage can be increased to hundreds of kilovolts and the current to tens of kiloamperes. This breaks through the voltage withstand limitation of single-transistor devices.

[0009] 2. High synchronization accuracy: By adopting fiber optic transmission and a precise synchronization triggering system, nanosecond-level synchronization of multi-tube triggering is achieved, effectively avoiding dynamic voltage equalization problems.

[0010] 3. High reliability isolation: The system employs reliable isolation technology on both the signal transmission (fiber optic) and energy supply (magnetic ring power supply) critical paths, ensuring the safety of the control section under high voltage conditions.

[0011] 4. Sufficient trigger energy: It adopts a dedicated isolated laser driver and low impedance coaxial transmission line, which can provide the laser diode with a steep leading edge and sufficient power trigger pulse, ensuring the rapid and reliable conduction of the thyristor.

[0012] 5. Comprehensive system protection: Static voltage equalization and overvoltage protection circuits are designed to improve the system's survivability under abnormal operating conditions.

[0013] 6. Low cost and easy to promote: This invention achieves high performance while being highly cost-effective. The core trigger source of the system uses a mature and inexpensive laser diode, instead of an expensive and bulky traditional solid-state laser; signal transmission uses conventional optical fiber, keeping costs under control; the power supply system innovatively adopts a simple and efficient architecture of magnetic ring isolation power supply, eliminating the need for multiple independent high-voltage isolation power supply modules. This selection and integration of low-cost, standardized components gives the entire system a significant advantage in material and manufacturing costs, laying a solid foundation for large-scale application and promotion. Attached Figure Description

[0014] Figure 1 This is a flowchart illustrating the workflow of the components of this invention.

[0015] Figure 2 Diagram of the magnetic ring isolated power supply system and isolated laser drive structure;

[0016] Figure 3 This is a structural diagram of the synchronous triggering system involved in this invention;

[0017] Figure 4 This is a diagram showing the arrangement of laser diodes in series.

[0018] Figure 5 This is a structural diagram of a light-controlled multi-gate thyristor chip. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other. To achieve the above objectives, this invention adopts the following technical solution.

[0020] like Figure 1 As shown, the present invention provides a high-voltage, high-current optically controlled solid-state switch assembly based on dual isolation, comprising: a synchronous triggering system, an optical fiber transmission line, an isolated laser driving unit, a coaxial transmission line, a laser diode series group, an optically controlled multi-gate thyristor, a low-voltage power supply system, a DC-AC inverter system, a magnetic ring isolated power supply system, and a static voltage equalization and protection system.

[0021] The external trigger signal first enters the synchronous triggering system, which converts the initial external trigger signal into multiple nanosecond-level synchronous weak light trigger signals. The weak light trigger signals are then transmitted losslessly to the isolated laser drive units on each high-voltage side via fiber optic transmission lines. After receiving the weak light trigger signals, the isolated laser drive units amplify the energy through internal high-speed power semiconductor switches and output electrical pulses. The electrical pulses are transmitted to the laser diode series group via coaxial transmission lines. The laser diode series group converts the electrical pulses into trigger light spots. The trigger light spots are matched with the optical windows of the optically controlled multi-gate thyristors to complete the photoelectric conversion and drive the thyristors to conduct. The static voltage equalization and protection system is connected in parallel across each optically controlled multi-gate thyristor. The low-voltage power supply system supplies power to the synchronous triggering system, and at the same time, the DC-AC inverter system supplies power to the magnetic ring isolated power supply system, which in turn supplies power to the isolated laser drive units.

[0022] Furthermore, the external trigger signal, serving as the initial command for system startup, is in the form of an optical signal and transmitted via optical fiber. This design fundamentally achieves electrical isolation between the control unit (low-voltage ground potential) and the power switching unit (high-voltage floating potential), effectively avoiding the harm to front-end precision control equipment caused by grounding interference and potential rise, and ensuring the safety of system operation and its resistance to electromagnetic interference.

[0023] Furthermore, such as Figure 3As shown, the synchronous triggering system is crucial for ensuring precise synchronous conduction of multiple switching transistors. This system is configured to receive a single optical pulse input IN from an external trigger signal and utilize internal high-precision timing and driving circuitry to generate multiple (e.g., 10) highly synchronized trigger optical signal outputs OUT. This "one-minute-plus" synchronization mechanism ensures that multiple subsequently isolated laser drivers can operate simultaneously within an extremely narrow time window (typically less than nanoseconds), thereby guaranteeing that the series-connected optically controlled multi-gate thyristors can conduct almost simultaneously, preventing damage to the devices due to uneven voltage distribution caused by asynchronous conduction.

[0024] Furthermore, the fiber optic transmission line is used to connect the synchronous triggering system to each isolated laser drive unit. Its core function is to achieve high-voltage electrical isolation and long-distance lossless signal transmission. Because the optical signal is transmitted in the optical fiber using the principle of total internal reflection, and its carrier is an insulating medium, it can withstand potential differences of tens to hundreds of kilovolts, perfectly solving the insulation problem between the high-voltage side and the low-voltage side. At the same time, fiber optic transmission has advantages such as large bandwidth, low loss, and immunity to electromagnetic interference, ensuring the quality of long-distance transmission of the trigger signal.

[0025] Furthermore, such as Figure 2 As shown, the isolated laser driver unit is the core component for triggering energy amplification. It is configured to receive a weak light trigger signal from the optical fiber and utilize an internal high-speed power semiconductor switch (such as a MOSFET) to generate an electrical pulse with a large current (hundreds of amperes) and a fast leading edge (nanoseconds) to directly drive the laser diode series group. The driver itself employs an isolated design, allowing its output to reliably operate at the high potential of the laser diode series group. The system draws power from the high-voltage bus via an isolation magnetic ring, achieves synchronous triggering through an optocoupler input, and finally outputs the high-voltage pulse to the laser diode series group through a low-impedance coaxial transmission line. Furthermore, the coaxial transmission line employs low impedance characteristics (e.g., 50Ω) to efficiently transmit the energy of the large current pulse generated by the isolated laser driver to the laser diode series group. Its technical advantages are as follows: First, the low impedance characteristic can minimize the loss of pulse energy and waveform distortion during transmission, ensuring a steep pulse leading edge; second, the coaxial shielding layer can suppress the electromagnetic radiation generated by the power pulse from interfering with the outside world and prevent external interference from intruding; third, it provides the necessary physical isolation, spatially separating the sensitive drive circuit from the laser diode group at the high voltage end, preventing the strong electromagnetic field generated during high voltage breakdown or potential change from causing destructive interference (such as self-excitation) to the drive circuit.

[0026] Furthermore, the laser diode series group consists of multiple laser diodes connected in series. Its technical features include: the number of diodes connected in series is determined by the required isolation voltage rating of the system; the spatial arrangement of each diode is optically designed so that the trigger spot formed by the emitted laser beam is highly matched in shape, size, and energy distribution to the trigger window of the optically controlled multi-gate thyristor. This design ensures that laser energy can be efficiently and uniformly injected into the trigger region of the thyristor chip, thereby achieving rapid and uniform triggering. The chip structure design of the optically controlled multi-gate thyristor aims to optimize light injection efficiency, and its multi-gate layout is as follows: Figure 4 As shown. The laser diode series group has 7 light-emitting units, which are precisely aligned with the 7 light-controlled gates of the light-controlled multi-gate thyristor to achieve triggering.

[0027] Furthermore, such as Figure 5 As shown, the optically controlled multi-gate thyristor series assembly is the core power switch of the system, comprising a trigger window 3, an anode 2, and a bottom cathode 1. To withstand high operating voltages (e.g., 50kV), several (e.g., 7) individual optically controlled multi-gate thyristors are connected in series to form the assembly. This device combines the high peak power capability of thyristors with the fast turn-on advantage of photoconductive switches. Its specific structure is a PNPN four-layer symmetrical design with multiple independent optical trigger gates, enabling synchronous conduction in multiple regions and effectively improving the turn-on speed (di / dt). The withstand voltage level of a single device (e.g., 8.5kV) and the number of units connected in series together determine the withstand voltage capability of the entire assembly. A series-connected laser diode array is vertically stacked, with each light-emitting unit precisely aligned with a trigger window.

[0028] Furthermore, the static voltage equalization and protection system is a necessary measure to ensure the long-term reliable operation of the series-connected components. Static voltage equalization is achieved by connecting high-voltage non-inductive resistors with the same resistance value in parallel across each series-connected thyristor, ensuring that the voltage is evenly distributed across each device according to the resistance ratio in the off state. The protection system is implemented by connecting fast high-voltage diodes in reverse parallel across each thyristor to absorb the reverse overvoltage energy generated by stray inductance during the turn-off process or in fault conditions, suppress voltage spikes, and protect the fragile semiconductor junction from avalanche breakdown damage.

[0029] Furthermore, the magnetic ring isolation power supply system innovatively solves the problem of simultaneously powering multiple isolated laser drive units suspended at a high potential. Its technical features include: using a common AC power bus that passes sequentially through a high-frequency magnetic ring (transformer core) installed on each isolated laser drive unit. Utilizing the transformer coupling principle, the AC power transmitted on the bus induces a voltage in the secondary winding of each magnetic ring, thereby simultaneously and electrically isolating the drive units at different potentials to provide operating power (e.g., 12V). The isolation withstand voltage capability (e.g., 100kV) of this system is determined by the magnetic ring material, winding structure, and insulation treatment process.

[0030] Furthermore, the function of the DC-AC inverter system is to convert the direct current (e.g., 12VDC) supplied by the low-voltage power supply system into alternating current (e.g., 12V AC). This conversion is a necessary prerequisite for providing an energy source for the magnetic ring isolated power supply system, because transformers can only couple changing magnetic fields (i.e., alternating current). The inverter needs to have a certain power capacity and conversion efficiency to support the normal operation of all isolated laser drive units.

[0031] Furthermore, the low-voltage power supply system provides a stable and clean DC power supply for the low-voltage control section of the entire system (mainly the synchronous triggering system and the DC-AC inverter system). It is the system's fundamental energy source, and the stability of its output voltage, ripple coefficient, and anti-interference capability directly affect the triggering synchronization accuracy and the overall system reliability.

[0032] This invention achieves a significant breakthrough in laser triggering paths. Through a highly efficient transparent coupling design between a series laser diode array and a light-controlled multi-gate thyristor chip, combined with high-voltage potting isolation technology, it ensures efficient transmission and electrical insulation of the trigger optical path. An optically optimized laser diode arrangement scheme ensures that the trigger spot perfectly matches the thyristor's optical window in shape, size, and energy distribution. Optical coupling is achieved through transparent potting material, significantly improving optical transmission efficiency. High-voltage potting isolation technology ensures reliable insulation at voltage levels of 50kV and below. The potting material also serves as an auxiliary material for heat dissipation and mechanical fixation.

[0033] The implementation of this technology enables laser energy to be injected into the trigger area of ​​the thyristor chip efficiently and uniformly, achieving rapid and uniform triggering and conduction, and laying a solid foundation for the high-voltage operation of the entire system.

[0034] This invention innovatively adopts a dual isolation technology solution to achieve high voltage isolation at both the power supply path and structural packaging levels, with the system isolation voltage capability reaching the 500kV level.

[0035] Structural encapsulation and isolation: The laser diode series group and the optically controlled multi-gate thyristor are integrated into the same module using high-transmittance potting compound to achieve high-voltage electrical insulation and efficient optical path coupling.

[0036] Energy supply path isolation: The magnetic ring isolation power supply system supplies power to each isolated laser drive unit through a common AC bus and a high-frequency magnetic ring, with an isolation withstand voltage exceeding 100kV.

[0037] The dual isolation paths work together to improve the system's insulation reliability.

[0038] The magnetic ring isolation power supply system supplies power to the drive units isolated at various potentials via a common AC power bus passing through a high-frequency magnetic ring. High-voltage components (referring to optically controlled multi-gate thyristors) undergo overall potting treatment to form a second isolation barrier. This dual isolation design significantly improves the system's insulation reliability and safety; the isolation voltage level reaches 500kV, meeting the requirements of ultra-high voltage applications. This dual isolation technology not only solves the power supply problem for high-potential floating units but also enhances the system's mechanical strength and environmental adaptability through potting, ensuring long-term stable operation under high-voltage environments.

[0039] In the packaging of optically controlled multi-gate thyristors, this invention employs advanced modular welding and multi-aluminum wire ring bonding technology, achieving high current carrying capacity while simplifying traditional press-fit structures. Modular welding: High-performance welding materials are used to achieve a reliable connection between the optically controlled multi-gate thyristor and the cathode lead plate of the multi-gate optically controlled thyristor; Multi-aluminum wire ring bonding: Multiple aluminum wires are used to achieve ring bonding between the multi-gate optically controlled thyristor and the PCB substrate, significantly reducing current carrying resistance; Compared with traditional thyristor press-fit structures, this simplifies the mechanical structure and improves reliability; It also optimizes current distribution and enhances di / dt tolerance.

[0040] The following embodiments further illustrate the present invention in detail.

[0041] In practical implementation, the number of series diodes (e.g., 7) is first determined based on the target output voltage (e.g., 50kV) and the single-diode withstand voltage (e.g., 8.5kV). Then, a synchronous triggering system is configured to match the number of output channels with the number of series diodes. The output pulse parameters (energy, pulse width) of the isolated laser driver and the arrangement of the laser diode series group are determined to ensure a good match between the trigger spot and the thyristor optical window. The resistance value of the static equalizing resistor must be precisely selected, and the withstand voltage rating of the protection diode should be higher than the single-diode operating voltage. The isolation withstand voltage of the magnetic ring isolated power supply system must be greater than the system's highest operating voltage. By rationally configuring the parameters of each subsystem, a high-performance, high-reliability optically controlled high-voltage switching system can be constructed, which can be widely used in high-tech fields such as accelerators and pulsed power sources.

Claims

1. A high-voltage, high-current optically controlled solid-state switch assembly based on dual isolation, characterized in that, include: The system includes a synchronous triggering system, fiber optic transmission line, isolated laser drive unit, coaxial transmission line, laser diode series group, light-controlled multi-gate thyristor, low-voltage power supply system, DC-AC inverter system, magnetic ring isolated power supply system, and static voltage equalization and protection system. The external trigger signal first enters the synchronous triggering system, which converts the initial external trigger signal into multiple nanosecond-level synchronous weak light trigger signals. The weak light trigger signals are then transmitted losslessly to the isolated laser drive units on each high-voltage side via fiber optic transmission lines. After receiving the weak light trigger signal, the isolated laser drive unit amplifies the energy through its internal high-speed power semiconductor switch and outputs an electrical pulse. The electrical pulse is transmitted to the laser diode series group via a coaxial transmission line. The laser diode series group converts the electrical pulse into a trigger light spot. The trigger light spot is matched with the optical window of the optically controlled multi-gate thyristor to complete the photoelectric conversion and drive the optically controlled multi-gate thyristor to conduct. The static voltage equalization and protection system is connected in parallel across each optically controlled multi-gate thyristor. The low-voltage power supply system supplies power to the synchronous triggering system, and at the same time, the DC-AC inverter system supplies power to the magnetic ring isolated power supply system.

2. The light-controlled solid-state switch assembly according to claim 1, characterized in that, The synchronous triggering system uses timing and driving circuits to convert a single input optical pulse into multiple trigger optical signals with highly consistent timing output, so that multiple subsequent isolated laser driving units can operate simultaneously within a nanosecond time window.

3. The light-controlled solid-state switch assembly according to claim 1, characterized in that, The optical fiber transmission line provides electrical isolation between the synchronous triggering system and the power switch.

4. The light-controlled solid-state switch assembly according to claim 1, characterized in that, The isolated laser driving unit uses a high-speed power semiconductor switch to generate electrical pulses with leading edges on the order of hundreds of amperes and nanoseconds, which directly drive the series-connected laser diode array.

5. The light-controlled solid-state switch assembly according to claim 1, characterized in that, The coaxial transmission line is a low-impedance transmission line and has a shielding layer.

6. The light-controlled solid-state switch assembly according to claim 1, characterized in that, The laser diode series group adopts an optically optimized spatial arrangement scheme, so that the trigger spot formed by the emitted laser beam is highly matched with the trigger window of the optically controlled multi-gate thyristor in terms of shape, size and energy distribution.

7. The light-controlled solid-state switch assembly according to claim 1, characterized in that, The component consisting of multiple optically controlled multi-gate thyristors connected in series has a withstand voltage of tens to hundreds of kilovolts and a current capacity of tens of kiloamperes.

8. The light-controlled solid-state switch assembly according to claim 1, characterized in that, The magnetic ring isolation power supply system uses a common AC power supply bus to pass through the high-frequency magnetic rings installed on each isolated laser drive unit in sequence, and induces a voltage in the secondary winding of each magnetic ring, with an isolation withstand voltage of over 100kV.

9. The light-controlled solid-state switch assembly according to claim 1, characterized in that, The static voltage equalization and protection system consists of a high-voltage non-inductive resistor connected in parallel across each optically controlled multi-gate thyristor and a fast high-voltage diode connected in reverse parallel, which respectively realizes static voltage equalization and reverse overvoltage energy absorption.

10. The light-controlled solid-state switch assembly according to claim 1, characterized in that, The optical fiber transmission line provides electrical isolation for the signal transmission path, and the magnetic ring isolation power supply system provides electrical isolation for the energy supply path. Together, they form a dual isolation architecture, and the total isolation voltage capability of the system reaches the 500kV level.

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