High-voltage and large-current light-operated solid-state switch assembly based on double isolation

Abstract

The invention discloses a high-voltage and large-current light-operated solid-state switch assembly based on double isolation, which relates to the field of particle accelerators, pulse power and power electronics and comprises a synchronous trigger system, an isolation laser driving unit, a laser diode series group and a light-operated multi-gate thyristor. An initial external trigger signal is converted into multiple paths of nanosecond-level synchronous weak light trigger signals, the weak light trigger signals are transmitted to each isolation laser driving unit in a lossless mode, and after the isolation laser driving units receive the weak light trigger signals, energy amplification is conducted through internal high-speed power semiconductor switches, and electric pulses are output. An electric pulse is transmitted to the laser diode series connection group through the coaxial transmission line, the laser diode series connection group converts the electric pulse into a trigger light spot, the trigger light spot is matched with a light window of the light-operated multi-gate thyristor, light-electricity conversion is completed, the thyristors are driven to be conducted, and the static voltage-sharing and protection system is connected to the two ends of each light-operated multi-gate thyristor in parallel.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of particle accelerators, pulse power, power electronics, and in particular to a high-voltage and high-current optical control solid-state switch assembly based on double isolation. BACKGROUND

[0002] In the field of pulse power, how to realize a solid-state switch with high peak power, fast turn-on speed and direct current charging is a key technical challenge. Although the traditional gas switch has high power capacity, it has problems such as short service life and large timing jitter. The existing solid-state switches such as thyristors and IGBTs face a series of complex technical problems such as trigger synchronization, dynamic voltage sharing, and high-voltage isolation power supply when they are connected in series to improve the withstand voltage level. In particular, for optical thyristors, the trigger synchronization accuracy and the stability of the isolated driving power supply when multiple thyristors are connected in series directly determine the reliability and performance upper limit of the entire system. Therefore, there is an urgent need for a highly integrated and reliable multi-stage optical control switch system solution. SUMMARY

[0003] The purpose of the present application is to overcome the shortcomings of the prior art and provide a high-voltage and high-current optical control solid-state switch assembly based on double isolation. Through innovative system architecture and circuit design, high-voltage series operation of multiple optical control multi-gate thyristors is realized, significantly improving the voltage and current level of the solid-state switch.

[0004] To achieve the above purpose, the present application adopts the following technical solutions:

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

[0006] Wherein, the external trigger signal first enters the synchronous trigger system, converts the initial external trigger signal into multiple nanosecond-level synchronous weak light trigger signals, and transmits the weak light trigger signals to the isolated laser driving unit on the high-voltage side through the optical fiber transmission line. After receiving the weak light trigger signal, the isolated laser driving unit amplifies the energy through the internal high-speed power semiconductor switch, outputs an electric pulse, and transmits the electric pulse to the laser diode series group through the coaxial transmission line. The laser diode series group converts the electric pulse into a trigger light spot, which matches the optical window of the optical control multi-gate thyristor, completes the photoelectric conversion, drives the thyristor to turn on, and the static voltage sharing and protection system is connected in parallel across each optical control multi-gate thyristor. The low-voltage power supply system supplies power to the synchronous trigger system, and simultaneously supplies power to the magnetic ring isolation power taking system through the DC-AC inverter system.

[0007] Compared with the prior art, the present application has the following remarkable beneficial effects:

[0008] 1. High-voltage and large-current level: through the series connection technology of the light-controlled multi-gate thyristor, the working voltage can be raised to the level of several hundred kilovolts, and the current can reach the level of several tens of kiloamperes. The voltage withstand limit of a single device is broken through.

[0009] 2. High synchronization accuracy: the nanosecond-level synchronization of the multi-tube triggering is realized through the use of the optical fiber transmission and the precise synchronization triggering system, and the dynamic voltage sharing problem is effectively avoided.

[0010] 3. High reliability isolation: reliable isolation technology is adopted in the two key paths of signal transmission (optical fiber) and energy supply (magnetic ring power taking), which ensures the safety of the control part in the high-voltage environment.

[0011] 4. Sufficient triggering energy: the use of special isolated laser drive and low-impedance coaxial transmission line can provide the laser diode with a front steep and sufficient power triggering pulse, which ensures the fast and reliable conduction of the thyristor.

[0012] 5. Perfect system protection: the static voltage sharing and overvoltage protection circuits are designed to improve the survival ability of the system under abnormal working conditions.

[0013] 6. Low cost and easy to promote: while pursuing high performance, the present application is cost-effective. The core trigger source of the system uses mature and low-cost laser diodes instead of expensive and bulky traditional solid-state lasers; the signal transmission uses conventional optical fibers, and the cost is controllable; the power supply system innovatively uses the simple and efficient architecture of the magnetic ring isolation power taking, which eliminates multiple independent high-voltage isolation power modules. This optimization and integration of low-cost and standardized components make the entire system have a significant advantage in material and manufacturing cost, laying a solid foundation for large-scale application and promotion. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 is the working flowchart of the components of the present application;

[0015] Figure 2 is the structure diagram of the magnetic ring isolation power taking system and the isolated laser drive;

[0016] Figure 3 is the structure diagram of the synchronization triggering system involved in the present application;

[0017] Figure 4 is the arrangement structure diagram of the laser diode string;

[0018] Figure 5 is the structure diagram of the light-controlled multi-gate thyristor chip. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below with reference to the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and not to limit the present application. In addition, the technical features involved in the various embodiments of the present application described below can be combined with each other as long as they do not conflict with each other. In order to achieve the above purpose, the present application adopts the following technical scheme.

[0020] As shown in Figure 1 The present application provides a high-voltage and high-current light-controlled solid-state switch assembly based on double 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, a light-controlled multi-gate thyristor, a low-voltage power supply system, a DC-AC inverter system, a magnetic ring isolation power taking system, a static voltage sharing and protection system.

[0021] Among them, the external trigger signal first enters the synchronous triggering system, converts the initial external trigger signal into a plurality of nanosecond-level synchronous weak light trigger signals, and transmits the weak light trigger signals to each high-voltage side isolated laser driving unit through the optical fiber transmission line. After receiving the weak light trigger signal, the isolated laser driving unit amplifies the energy through the internal high-speed power semiconductor switch, outputs an electric pulse, and transmits the electric pulse to the laser diode series group through the coaxial transmission line. The laser diode series group converts the electric pulse into a trigger spot, the trigger spot matches the light window of the light-controlled multi-gate thyristor, completes the photoelectric conversion, drives the thyristor to conduct, and the static voltage sharing and protection system is connected in parallel between each light-controlled multi-gate thyristor. The low-voltage power supply system supplies power to the synchronous triggering system, and at the same time supplies power to the magnetic ring isolation power taking system through the DC-AC inverter system, and the magnetic ring isolation power taking system supplies power to the isolated laser driving unit.

[0022] Further, the external trigger signal is used as the initial instruction for starting the system, in the form of optical signal and transmitted through optical fiber medium. This design fundamentally realizes the electrical isolation between the control unit (low-voltage ground potential) and the power switch unit (high-voltage floating potential), effectively avoids the harm of common ground interference and potential lifting to the front-end precision control equipment, and ensures the safety and anti-electromagnetic interference capability of the system operation.

[0023] Further, as shown in Figure 3As shown, the synchronous trigger system is the key to ensure the accurate synchronization of multiple switch tubes. The system is configured to receive a light pulse input IN from an external trigger signal, and use the internal high-precision timing and driving circuit to generate multiple (for example, 10) highly consistent trigger light signal outputs OUT in time sequence. This "1+ multiple" synchronization mechanism ensures that the subsequent multiple isolated laser drivers can act simultaneously within a very narrow time window (usually less than nanoseconds), thereby ensuring that the series of light-controlled multi-gate thyristors can be turned on at almost the same time, avoiding damage to the device due to uneven voltage distribution caused by different synchronization of the turn-on.

[0024] Further, the optical fiber transmission line is used to connect the synchronous trigger system and each isolated laser driving unit. Its core function is to achieve high-voltage electrical isolation and long-distance lossless signal transmission. Since the optical signal is transmitted in the optical fiber by total reflection principle, its carrier is an insulating medium, and therefore it can withstand a potential difference 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, optical fiber transmission has the advantages of large bandwidth, low loss, and immunity to electromagnetic interference, ensuring the quality of long-distance transmission of the trigger signal.

[0025] Further, as shown in Figure 2 The isolated laser driving unit is the core component of trigger energy amplification. It is configured to receive a weak light trigger signal from the optical fiber, and use the internal high-speed power semiconductor switch (such as MOSFET) to generate an electric pulse with large current (hundreds of amperes) and fast front (nanoseconds) characteristics, which is used to directly drive the laser diode string. The driver itself adopts an isolated design, so that its output end can reliably reference the high potential at which the laser diode string is located. The system takes power from the high-voltage bus through an isolated magnetic ring, synchronously triggers through optical coupling input, and finally outputs high-voltage pulses to the laser diode string through a low-impedance coaxial transmission line. Further, the coaxial transmission line adopts a low-impedance characteristic (such as 50Ω), which is used to efficiently transmit the large-current pulse energy generated by the isolated laser driver to the laser diode string. Its technical effects are as follows: first, the low-impedance characteristic can minimize the loss and waveform distortion of the pulse energy during transmission, ensuring a steep pulse front; second, the shielding layer of the coaxial structure can suppress the electromagnetic radiation generated by the power pulse and prevent external interference from invading; third, it provides the necessary physical isolation to separate the sensitive driving circuit from the laser diode group at the high-voltage end in space, preventing the strong electromagnetic field generated by high-voltage breakdown or potential mutation from causing destructive interference (such as self-excitation) to the driving circuit.

[0026] Further, the laser diode series group is composed of a plurality of laser diodes in series, and the technical features are as follows: the number of series is determined according to the required isolation voltage level of the system; the spatial arrangement of each diode is designed to make the trigger light spot formed by the laser beams emitted by the diodes highly match the trigger light window of the optically controlled multi-gate thyristor in shape, size and energy distribution. This design ensures that the laser energy can be efficiently and uniformly injected into the trigger area of the thyristor chip, thereby realizing fast and uniform triggering and conduction. The chip structure design of the optically controlled multi-gate thyristor aims to optimize the light injection efficiency, and the multi-gate layout is as shown in Figure 4 The laser diode series group has 7 light-emitting units, which are precisely aligned with the 7 optically controlled gates of the optically controlled multi-gate thyristor, to realize triggering.

[0027] Further, as shown in Figure 5 The optically controlled multi-gate thyristor series assembly is the core power switch of the system, which includes a trigger light window 3, an anode 2 and a bottom cathode 1. To withstand high operating voltage (such as 50kV), a plurality of (such as 7) single optically controlled multi-gate thyristors are connected in series to form the assembly. This device combines the high peak power capability of thyristors and the fast conduction advantage of photoconductive switches. Its specific structure is a PNPN four-layer symmetric design, which has multiple independent light trigger gates and can realize multi-region synchronous conduction, effectively improving the conduction speed (di / dt). The voltage withstand level of a single device (such as 8.5kV) and the number of series determine the voltage withstand capability of the entire assembly. The series laser diode group is vertically stacked, and each light-emitting unit is precisely aligned with a trigger light window.

[0028] Further, the static voltage equalization and protection system is a necessary measure to ensure the long-term reliable operation of the series assembly. Static voltage equalization is achieved by connecting high-voltage non-inductive resistors with consistent resistance in parallel at both ends of each series thyristor, ensuring that the voltage is evenly distributed among the devices in the off state. The protection system is achieved by connecting fast high-voltage diodes in reverse parallel at both ends of each thyristor, which is used to absorb the reverse overvoltage energy generated by stray inductance during the off process or in fault conditions, to suppress voltage spikes and protect fragile semiconductor junctions from avalanche breakdown damage.

[0029] Further, the magnetic ring isolation power taking system innovatively solves the problem of simultaneously supplying power to multiple isolated laser drive units suspended at high potentials. The technical features are as follows: a common AC power bus is used, which sequentially passes through high-frequency magnetic rings (transformer magnetic cores) installed on each isolated laser drive unit. By using 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 isolatedly providing working power (such as 12V) for each drive unit at different potentials. The isolation withstand voltage capability (such as 100kV) of the system is determined by the magnetic ring material, winding structure, and insulation processing technology.

[0030] Further, the function of the DC-AC inverter system is to invert the DC power (such as 12VDC) provided by the low-voltage power supply system into AC power (such as 12V AC). This conversion is a necessary prerequisite for the magnetic ring isolation power taking system to provide energy sources, because transformers can only couple varying magnetic fields (i.e. AC power). The inverter needs to have a certain power capacity and conversion efficiency to support the normal operation of all isolated laser drive units.

[0031] Further, the low-voltage power supply system provides stable and clean DC power for the low-voltage control part of the entire system (mainly the synchronous triggering system and the DC-AC inverter system). It is the basic energy source of the system, and the stability, ripple factor, and anti-interference ability of its output voltage directly affect the triggering synchronization accuracy and the reliability of the entire system.

[0032] The present application achieves a major breakthrough in the laser triggering path. Through the efficient transparent coupling design between the series connection of laser diodes and the optically controlled multi-gate thyristor chip, combined with high-voltage encapsulation isolation technology, the efficient transmission and electrical insulation of the triggering optical path are ensured. The optical optimization of the laser diode arrangement scheme makes the triggering light spot perfectly match the thyristor light window in shape, size, and energy distribution; the optical path coupling is realized through transparent encapsulation materials, and the optical transmission efficiency is significantly improved; the high-voltage encapsulation isolation technology ensures reliable insulation at a voltage level of 50kV and below; the encapsulation material also plays an auxiliary role in heat dissipation and mechanical fixation.

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

[0034] The present application innovatively adopts a double isolation technology scheme, achieving high-voltage isolation at two levels of power supply path and structural packaging, and the system isolation voltage capability reaches the 500kV level.

[0035] Structure encapsulation isolation: the laser diode series group and the optically controlled multi-gate thyristor are integrated in the same module through high-transmittance pouring glue, so that high-voltage electrical insulation and high-efficiency optical coupling are realized.

[0036] Energy supply path isolation: the magnetic ring isolation power taking system supplies power to each isolated laser driving unit through a common AC bus and a high-frequency magnetic ring, and the isolation withstand voltage is more than 100 kV.

[0037] The double isolation paths improve the insulation reliability of the system.

[0038] The magnetic ring isolation power taking system supplies power to each potential isolated driving unit through a common AC power bus passing through a high-frequency magnetic ring; the high-voltage components are integrally poured to form a second isolation barrier; (the high-voltage component refers to the optically controlled multi-gate thyristor). The double isolation design greatly improves the insulation reliability and safety of the system; the isolation voltage level reaches 500 kV, meeting the application requirements of super-high voltage; this double isolation technology not only solves the power supply problem of the high-potential floating unit, but also enhances the mechanical strength and environmental adaptability of the system through the pouring process, providing a guarantee for long-term stable operation in a high-voltage environment.

[0039] In the packaging of the optically controlled multi-gate thyristor, the application adopts advanced modular welding and multi-aluminum wire ring bonding technology to realize large-current current passing capability while simplifying the traditional crimping structure. Modular welding: high-performance welding materials are used to realize reliable connection of the cathode lead-out plate of the optically controlled multi-gate thyristor and the multi-gate optically controlled thyristor; multi-aluminum wire ring bonding: multi-aluminum wires are used to realize ring bonding of the multi-gate optically controlled thyristor and the PCB substrate, greatly reducing the current passing impedance; compared with the traditional thyristor crimping structure, the mechanical structure is simplified, the reliability is improved, the current distribution is optimized, and the di / dt tolerance is improved.

[0040] The following examples further illustrate the application.

[0041] In specific implementation, first, the number of series-connected tubes (such as 7) is determined according to the target output voltage (such as 50 kV) and the single-tube withstand voltage (such as 8.5 kV). Then, the synchronous trigger system is configured so that the number of output channels matches the number of series-connected tubes. The output pulse parameters (energy, pulse width) of the isolated laser drive and the arrangement of the laser diode series group are matched to ensure that the trigger light spot and the thyristor light window are well matched. The resistance value of the static voltage balancing resistor needs to be accurately selected, and the withstand voltage level of the protection diode should be higher than the single-tube working voltage. The isolation withstand voltage of the magnetic ring isolation power taking system needs to be greater than the highest working voltage of the system. By reasonably configuring the parameters of each subsystem, a high-performance and high-reliability optically controlled high-voltage switching system can be constructed, which can be widely used in high-tech fields such as accelerators and pulse 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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