High-voltage ignition protection device for stabilized current power supply

Abstract

The invention discloses a high-voltage ignition protection device for a stabilized current power supply, which comprises an active protection unit and a passive protection unit, and is characterized in that the active protection unit is connected to a control input end of a high-voltage power supply and works under power frequency voltage; the passive protection unit is connected between the power supply input end of the stabilized current power supply and 220V commercial power and works under power frequency voltage; the active protection unit is used for protecting the ion source stabilized current power supply aiming at a partial discharge phenomenon before high-voltage ignition; the passive protection unit carries out ion source current stabilization power supply protection aiming at a high-voltage sparking phenomenon without partial discharge. Active protection and passive protection are combined and applied to the field of ignition protection of the ECR ion source, and high accuracy and quick response are achieved. And technologies such as lightning surge protection, a differential-mode and common-mode noise processing method, seismological partial discharge detection and the like are creatively applied to the field of high-voltage ignition noise protection of the power supply in a cross-field manner.

Description

Technical Field

[0001] This invention relates to the field of ion sources and their supporting equipment, specifically to a high-voltage arc protection device for a constant current power supply. Background Technology

[0002] Electron cyclotron resonance (ECR) ion sources are crucial for generating highly charged ions, and their stable operation is essential for downstream accelerators and other devices. Existing ECR ion source power systems mainly consist of two parts: a high-voltage, low-current extraction electrode high-voltage power supply and a low-voltage, high-current steady-state power supply providing the strong magnetic field required to generate confined plasma. The efficient and stable operation of an ECR ion source depends on the precise, coordinated, and simultaneous output of these two power sources.

[0003] However, existing ECR ion sources (such as...) Figure 1 The structure shown faces a critical challenge: in the high-voltage extraction region, there exists an extremely strong electric field gradient between the source (typically at ground potential) and the extraction electrode subjected to a high negative voltage. This strong electric field easily induces electrical breakdown, i.e., high-voltage arcing or sparking. Such arcing events not only instantaneously disrupt the local electric field distribution, but the resulting transient shocks also pose widespread hazards.

[0004] The common method for solving the sparking problem using existing technology is: sparking occurs -> shutdown -> manual disassembly and physical polishing of the electrode surface (to remove burrs or contaminants) -> reassembly -> startup. However, sparking often recurs within a short period, forcing the above process to be repeated. This frequent manual intervention, disassembly, maintenance, and shutdown not only results in significant waste of manpower but also leads to considerable spare parts wear (such as electrode materials and seals) and a substantial reduction in equipment uptime, greatly increasing overall operation and maintenance costs. Summary of the Invention

[0005] This invention addresses the problems existing in the prior art by proposing a high-voltage arcing protection device for a constant current power supply. The purpose is to solve the problem that frequent manual intervention, disassembly, maintenance, and shutdown are required when high-voltage arcing occurs in existing ECR ion sources, which not only causes significant waste of manpower but also greatly increases the overall operation and maintenance costs.

[0006] To solve its technical problems, the present invention proposes the following technical solutions:

[0007] A high-voltage arcing protection device for a constant current power supply is characterized by comprising an active protection unit and a passive protection unit. The active protection unit is connected to the control input terminal of the high-voltage power supply and operates under power frequency voltage. The passive protection unit is connected between the power input terminal of the constant current power supply and the 220V mains power and operates under power frequency voltage. The active protection unit protects the ion source constant current power supply against partial discharge phenomena prior to high-voltage arcing. The passive protection unit protects the ion source constant current power supply against high-voltage arcing phenomena without partial discharge.

[0008] Furthermore, the active protection unit protects the ion source stabilizing power supply against partial discharge phenomena prior to high-voltage ignition. Specifically, the active protection unit sequentially comprises: a bandpass filter, a high-frequency current sensor, a high-frequency signal processing unit, an analog-to-digital converter (ADC), a digital processing unit, and a protection execution unit. The high-frequency current sensor is used to collect real-time partial discharge signals from the high-voltage output circuit and send them to the high-frequency signal processing unit. The high-frequency signal processing unit performs bandpass filtering and amplification on the collected partial discharge signals and sends them to the analog-to-digital converter unit. The analog-to-digital converter (ADC) digitizes the filtered partial discharge signals. The digital processing unit calculates and executes detection programs on the partial discharge digital signals and sends them to the protection execution unit. The protection execution unit receives the partial discharge digital signals and determines whether to issue a protection action to the high-voltage power supply, wherein the protection action is to reduce or interrupt the high-voltage output energy.

[0009] Furthermore, the high-frequency current transformer is used to collect real-time partial discharge signals of the high-voltage output circuit, specifically: the time of active protection action is less than the partial discharge time before high-voltage arcing.

[0010] Furthermore, the digital processing unit is used to calculate and execute detection programs on the partial discharge digital signal. Specifically, the digital processing unit includes a derivative calculation detection subunit and an energy calculation detection subunit. The derivative calculation detection subunit is used to monitor current rising edge fluctuations and generate a first detection signal S1. The energy calculation detection subunit is used to monitor energy change fluctuations and generate a second detection signal S2. S1 and S2 are respectively sent to the protection execution unit.

[0011] 5. A high-voltage arcing protection device for a constant current power supply of an ECR ion source according to claim 4, characterized in that: the derivative calculation and detection subunit is used to monitor the current rising edge fluctuation, specifically: calculating the first derivative of the current dI / dT in real time, and using the first derivative with a set slope threshold T S The comparison generates a first detection signal S1; the slope threshold T S Defined as background slope μ dI / dTWith standard deviation σ dI / dT linear combination T S =μ dI / dt +k2σ dI / dt The value of k2 ranges from 4 to 12.

[0012] Furthermore, the energy calculation and detection subunit is used to monitor energy fluctuations, specifically by calculating the ratio R(t) = STA / LTA of the short-term energy average STA and the long-term energy average LTA, and comparing it with a set ratio threshold T. R The comparison generates a second detection signal S2; the STA window length is 0.1ms to 1ms, and the LTA window length is 5ms to 50ms; the threshold values ​​for STA / LTA range from 3 to 12.

[0013] Furthermore, when the S1 and S2 signals appear successively within a time window less than Δt, it is determined that a partial discharge phenomenon has occurred, and a protection signal Sp is output. Δt is the upper limit of the time for judging partial discharge, and its value ranges from 0.1ms to 5ms, which can be finely adjusted according to the operating conditions.

[0014] Furthermore, the passive protection unit provides ion source stabilization power supply protection for high-voltage arcing without partial discharge. Specifically, the passive protection unit is equipped with a first-stage energy discharge module, a second-stage common-mode suppression module, and a third-stage differential-mode suppression module. The first-stage energy discharge module is used to bypass and discharge the large arcing energy to prevent subsequent modules from being damaged. The second-stage common-mode suppression module is used to suppress common-mode noise in the high-frequency arcing signal. The third-stage differential-mode suppression module is used to suppress differential-mode noise in the high-frequency arcing signal. After filtering by the three modules, the high-voltage arcing energy is limited to a safe level without affecting the normal passage of the power frequency signal.

[0015] Furthermore, the first-stage energy discharge module includes a gas discharge tube (GDT) and a varistor (MOV). The GDT is connected before the MOV and protects the MOV. The MOV discharges ignition energy. The second-stage common-mode suppression module includes an anti-saturation inductor at the front end and a voltage regulator capacitor at the rear end. The anti-saturation inductor suppresses common-mode noise, and the voltage regulator capacitor provides a path to ground for common-mode noise. The saturation current of the anti-saturation inductor is higher than its rated current. The third-stage differential-mode suppression module includes a ferrite bead inductor at the front end and a small-capacity high-frequency capacitor at the rear end. The ferrite bead inductor suppresses differential-mode noise, and the small-capacity high-frequency capacitor provides a path for differential-mode noise.

[0016] Advantages and effects of the present invention

[0017] 1. Combining active and passive protection in the field of ECR ​​ion source arc protection, and based on the characteristics of arcing, adopting a dual-signal triggering mode based on adaptive threshold and energy ratio fusion algorithm to achieve high accuracy and fast response.

[0018] 2. An adaptive threshold algorithm is adopted for the protection threshold, which enables the protection device to work for a long time in high noise and high frequency interference environments, and has the ability to automatically update parameters and has self-learning ability.

[0019] 3. Innovatively, technologies such as lightning surge protection, differential and common mode noise processing methods, and seismic partial discharge detection are applied across fields to the field of high-voltage arcing noise protection for power supplies.

[0020] 4. When arcing occurs at the lead-out electrode of a typical ECR ion source, researchers usually consider modifying the mechanical structure, which is time-consuming and labor-intensive for the already manufactured source. However, protecting the power input is more economical and time-saving for ECR ion sources where arcing is less frequent. Attached Figure Description

[0021] Figure 1 This is a diagram illustrating the high-voltage arc protection device and arc path of the present invention.

[0022] Figure 2 This is a schematic diagram of the active protection unit structure of the present invention;

[0023] Figure 3 This is a schematic diagram of the passive protection part of the present invention;

[0024] Figure 4 This is a schematic diagram of the structure of the first-stage energy discharge module of the present invention;

[0025] Figure 5 This is a schematic diagram of the structure of the secondary common-mode suppression module of the present invention;

[0026] Figure 6 This is a schematic diagram of the three-level differential mode suppression module structure of the present invention;

[0027] Figure 7 This is a flowchart illustrating the operation of the active protection unit and the passive protection unit of the present invention.

[0028] Figure 8 Equivalent diagram of high-frequency noise response. Detailed Implementation

[0029] Innovation of this invention

[0030] 1. Active + Passive Dual Protection Mechanism: A pioneering active protection layer prevents fires before they occur. This overcomes the limitations of existing technologies that rely solely on reactive measures. By intervening with active protection before a fire breaks out, combined with passive protection to handle unexpected situations, a more comprehensive and reliable dual-insurance system is formed.

[0031] 2. Active Early Warning Based on Partial Discharge Detection: Partial discharge (PD) monitoring is introduced as an early warning signal source for potential sparking. Existing technologies cannot predict sparking. This method analyzes PD characteristics through real-time high-frequency current sensing and a signal processing chain (bandpass filtering, amplification, ADC, DSP) to predict sparking, providing a basis for active protection and significantly reducing the probability of sparking.

[0032] 3. Dual-signal triggering mode: Combining "derivative calculation detection" (fast response) and "energy calculation detection" (strong anti-interference), the energy ratio fusion improves decision-making accuracy. This solves the problems of accuracy and response speed in PD signal detection under high-noise environments, effectively avoiding false alarms and missed alarms, and is a key guarantee for the reliability of proactive early warning.

[0033] 4. Cross-domain protection technology application (lightning surge / noise suppression): This method creatively transplants lightning surge protection (GDT, MOV) and differential / common mode noise suppression technologies (anti-saturation inductors, voltage-regulating capacitors, ferrite beads) into the ECR arcing protection field. Existing technologies have weak capabilities in handling arcing noise. This method constructs a multi-stage filtering and suppression module to effectively suppress transient energy and high-frequency electromagnetic interference (EMI) generated by arcing, protecting the safety of the downstream power supply (regulated power supply).

[0034] Design difficulties of this invention

[0035] The protective device must be able to withstand high-voltage, high-energy noise surges, suppress high-frequency noise conduction while maintaining uninterrupted power frequency signal conduction, and possess long-term serviceability and fail-safe features. Conventional surge protectors (SPDs) can only handle ordinary lightning surges or high-voltage operation of high-power equipment; they will immediately fail when faced with high-voltage arcing noise. The protective device must be parameter-designed to reduce noise disturbances to an acceptable level for the protected equipment, meeting three conditions: it must be able to withstand high-voltage, high-energy noise surges, suppress high-frequency noise conduction while maintaining uninterrupted power frequency signal conduction, and possess long-term serviceability and fail-safe features.

[0036] Solutions to difficulties

[0037] 1. To address the problem of high-voltage, high-energy noise impact, this invention adopts an active-passive combined approach. While minimizing discharge energy, it uses a combination of gas discharge tube (GDT) and varistor (MOV) at the power input terminal to discharge high-energy noise signals in the pre-stage. When the power frequency signal passes through, it presents a high-impedance state, approximately an open circuit state. When high voltage is applied across the first-stage discharge module, the module responds quickly, clamping the voltage to a low level within nanoseconds, and a portion of the energy is consumed by the varistor (MOV).

[0038] 2. To address the issue of protection devices blocking high-frequency signals while allowing power frequency signals, this invention employs a method of winding the neutral and live wires in the same direction around both ends of the iron core. This makes the common-mode inductance almost zero under power frequency signals, while exhibiting high inductance when high-frequency common-mode noise is transmitted, effectively suppressing the transmission of common-mode noise. A large-capacity voltage-stabilizing capacitor is used to provide a path to ground for the common-mode noise.

[0039] 3. To address the issues of long-term use and failure protection, this invention employs an adaptive threshold algorithm to automatically update protection parameters, enabling reliable operation in harsh environments over extended periods. Furthermore, in the primary discharge module, a gas discharge tube (GDT) is used as the pre-stage for the varistor (MOV), avoiding the aging and even fire problems associated with using a separate varistor (MOV). Adding the GDT not only effectively eliminates leakage current from the varistor (MOV) but also prevents overheating or combustion caused by aging, saving costs and ensuring safety and reliability.

[0040] Based on the above principles, this invention designs a high-voltage arcing protection device for a constant current power supply of an ECR ion source, such as... Figures 1-8 As shown, its features are: it includes an active protection unit and a passive protection unit. The active protection unit is connected to the control input terminal of the high-voltage power supply and operates under the power frequency voltage; the passive protection unit is connected between the power input terminal of the regulated power supply and the 220V mains power and operates under the power frequency voltage; the active protection unit protects the ion source regulated power supply against partial discharge phenomena before high-voltage arcing; the passive protection unit protects the ion source regulated power supply against high-voltage arcing phenomena without partial discharge.

[0041] like Figures 1-8The active protection unit shown protects the ion source stabilizing power supply against partial discharge phenomena prior to high-voltage ignition. Specifically, the active protection unit sequentially comprises: a bandpass filter, a high-frequency current sensor, a high-frequency signal processing unit, an analog-to-digital converter (ADC), a digital processing unit, and a protection execution unit. The high-frequency current sensor collects real-time partial discharge signals from the high-voltage output circuit and sends them to the high-frequency signal processing unit. The high-frequency signal processing unit performs bandpass filtering and amplification on the collected partial discharge signals and sends them to the analog-to-digital converter unit. The analog-to-digital converter (ADC) digitizes the filtered partial discharge signals. The digital processing unit calculates and executes detection programs on the partial discharge digital signals and sends them to the protection execution unit. The protection execution unit receives the partial discharge digital signals and determines whether to issue a protection action to the high-voltage power supply, wherein the protection action is to reduce or interrupt the high-voltage output energy.

[0042] like Figures 1-8 The high-frequency current transformer shown is used to collect real-time partial discharge signals of the high-voltage output circuit. Specifically, the time of active protection action is less than the partial discharge time before high-voltage arcing.

[0043] like Figures 1-8 As shown, the digital processing unit is used to calculate and execute detection programs on the partial discharge digital signal. Specifically, the digital processing unit includes a derivative calculation detection subunit and an energy calculation detection subunit. The derivative calculation detection subunit is used to monitor the current rising edge fluctuation and generate a first detection signal S1. The energy calculation detection subunit is used to monitor energy change fluctuation and generate a second detection signal S2. S1 and S2 are respectively sent to the protection execution unit.

[0044] like Figures 1-8 As shown, the derivative calculation and detection subunit is used to monitor current rise edge fluctuations. Specifically, it calculates the first derivative of the current, dI / dT, in real time and uses the first derivative with a set slope threshold T. S The comparison generates a first detection signal S1; the slope threshold T S Defined as background slope μ dI / dT With standard deviation σ dI / dT linear combination T S =μ dI / dt +k2σ dI / dt The value of k2 ranges from 4 to 12.

[0045] like Figures 1-6 As shown, the energy calculation and detection subunit is used to monitor energy fluctuations. Specifically, it calculates the ratio R(t) = STA / LTA, which is the short-term energy average STA to the long-term energy average LTA, and compares it with a set ratio threshold T. RThe comparison generates a second detection signal S2; the STA window length is 0.1ms to 1ms, and the LTA window length is 5ms to 50ms; the threshold values ​​for STA / LTA range from 3 to 12.

[0046] like Figures 1-8 As shown, when signals S1 and S2 appear successively within a time window less than Δt, a partial discharge phenomenon is determined to have occurred, and a protection signal Sp is output. t To determine the upper limit of the duration of partial discharge, the value ranges from 0.1ms to 5ms and can be finely adjusted according to the operating conditions.

[0047] like Figures 1-8 As shown, the passive protection unit provides ion source stabilization power supply protection for high-voltage arcing without partial discharge. Specifically, the passive protection unit sequentially includes a primary energy discharge module, a secondary common-mode suppression module, and a tertiary differential-mode suppression module. The primary energy discharge module is used to bypass and discharge the large arcing energy to prevent subsequent modules from being damaged. The secondary common-mode suppression module is used to suppress common-mode noise in the high-frequency arcing signal. The tertiary differential-mode suppression module is used to suppress differential-mode noise in the high-frequency arcing signal. After filtering by these three modules, the high-voltage arcing energy is limited to a safe level without affecting the normal passage of the power frequency signal.

[0048] like Figures 1-8 As shown, the first-stage energy discharge module includes a gas discharge tube (GDT) and a varistor (MOV). The GDT is connected before the MOV and protects the MOV. The MOV discharges ignition energy. The second-stage common-mode suppression module includes an anti-saturation inductor at the front end and a voltage regulator capacitor at the rear end. The anti-saturation inductor suppresses common-mode noise, and the voltage regulator capacitor provides a path to ground for common-mode noise. The saturation current of the anti-saturation inductor is higher than its rated current. The third-stage differential-mode suppression module includes a ferrite bead inductor at the front end and a small-capacity high-frequency capacitor at the rear end. The ferrite bead inductor suppresses differential-mode noise, and the small-capacity high-frequency capacitor provides a path for differential-mode noise.

[0049] Supplementary Note 1

[0050] The ferrite bead inductor in the three-stage differential mode suppression module has almost zero impedance to low-frequency signals, exhibiting high impedance at its operating frequency. The small-capacity high-frequency capacitor in the three-stage high-frequency suppression module exhibits low impedance when encountering high-frequency signals. When the high-voltage ignition signal arrives after passing through the first-stage energy dissipation module and the second-stage common-mode suppression module, it no longer possesses high energy, but still contains abundant high-frequency noise. At this point, the ferrite bead inductor converts the high-frequency noise energy into heat, dissipating it. The small-capacity high-frequency capacitor provides a low-impedance path to ground for the high-frequency noise, exhibiting fast response and eliminating nanosecond-level spikes.

[0051] The high-frequency current transformer is mounted on the grounding wire of the high-voltage power supply. When the high-voltage power supply is operating normally, it outputs a DC high voltage, and the high-frequency current transformer will not collect any signal. However, when partial discharge occurs on the electrodes, a weak pulse current will appear on the grounding wire. At this time, the high-frequency current transformer will collect the pulse signal and output a high level to the logic circuit. The response speed of the high-frequency current transformer can reach 1μs.

[0052] The energy released during arcing is the charge accumulated between the electrodes. Reducing the output level when arcing is about to occur cannot completely prevent it, but it can prevent the arcing from becoming more intense. The pulse caused by this arcing still requires passive protection of the circuit.

[0053] The distance between any two wires inside the fire protection device should be greater than 2.5cm (the air breakdown distance for 30kV is 1cm), otherwise air breakdown may easily occur.

[0054] Example 1: Formula Calculation and Numerical Selection for Active Protection

[0055] Sensor and front end: HFCT (bandwidth 0.1MHz-20MHz, 50Ω) is clamped in the HV output circuit; the front end uses a bandpass filter (10kHz-5MHz).

[0056] Data acquisition: ADC sampling rate 10MS / s, resolution 12bit.

[0057] Fast-track implementation: Differential calculation of dI / dt is performed in the DSP, and a hardware comparator is used to compare dynamic thresholds (μ and σ are obtained by statistical analysis under normal operating conditions for 5 seconds during the startup phase). When |I|>μ+8σ or |dI / dt|>μ d +8σ d An interrupt signal is immediately output on the DSP to drive the trigger device. Typical response time is <10μs.

[0058] Confirmation of channel implementation: Implement an STA / LTA buffer in the DSP, with an STA window of 0.5ms (5000 samples) and an LTA window of 20ms (20000 samples). Use a sliding accumulator and exponential moving average to reduce computation. If STA / LTA > 6 for a duration > 0.3ms, then S2 is valid.

[0059] Joint judgment: In the logic, Δt = 1ms is set. If S1 and S2 are true within Δt, SP is output. If only S1 appears, a short-term bypass is triggered (lasting 5ms) to wait for S2 to confirm.

[0060] Protection execution: The SP signal drives the spark gap (trigger delay <2μs) and simultaneously sends a signal to the HV main controller via optical fiber to achieve rapid energy bypass and subsequent power cut-off.

[0061] Event logging: All triggered events are saved as 2ms raw waveforms at a rate of 10MS / s, with UTC timestamps, written to local storage and reported to the monitoring server.

[0062] Example 2: Theoretical Calculation and Installation of Passive Protection Section

[0063] This part of the device is installed at the power input terminal of the constant current power supply. It must effectively suppress high-frequency arcing noise and also provide good conduction of the power frequency signal. Its transfer function can be simplified as follows:

[0064]

[0065] The frequency of the conduction signal (50Hz) differs significantly from the frequency of the noise signal (140kHz). According to the Butterworth filtering principle, the transfer function should be:

[0066]

[0067] Cutoff frequency selection f c =500Hz,

[0068] When dealing with high-frequency noise signals, the filter circuit can be equivalent to... Figure 8 Where L2 = L4 = 11.255 mH and C1 = 9 μF.

[0069] Obtain the transfer function

[0070]

[0071] Substituting f = 50Hz and f = 140kHz respectively, we can obtain that its attenuation for power frequency signals is -0.00043dB and its attenuation for high-frequency noise is -97.89dB.

Claims

1. A high voltage spark protection device for a regulated power supply, characterized by: The active protection unit is connected to the control input end of the high-voltage power supply and works under the power frequency voltage; the passive protection unit is connected between the power input end of the steady current power supply and the 220V mains and works under the power frequency voltage; The active protection unit protects the ion source steady current power supply against the local discharge phenomenon before high-voltage sparking; The passive protection unit protects the ion source steady current power supply against the high-voltage sparking phenomenon without local discharge.

2. A high voltage spark protection device for a regulated power supply as defined in claim 1, characterized in that: The active protection unit protects the ion source steady current power supply against the local discharge phenomenon before high-voltage sparking, specifically, the active protection unit is sequentially provided with a band-pass filter, a high-frequency current sensor, a high-frequency signal processing unit, an analog-to-digital conversion unit (ADC), a digital processing unit and a protection execution unit; the high-frequency current transformer is used to collect real-time local discharge signals of the high-voltage output loop and send them to the high-frequency signal processing unit; the high-frequency signal processing unit is used to band-pass filter and amplify the collected local discharge signals and send them to the analog-to-digital conversion unit; the analog-to-digital conversion unit (ADC) is used to digitize the filtered local discharge signals; the digital processing unit is used to calculate and execute detection programs on the local discharge digital signals and send them to the protection execution unit; the protection execution unit is used to receive the local discharge digital signals and judge whether to issue a protection action on the high-voltage power supply, and the protection action is to reduce or interrupt the high-voltage output energy.

3. A high voltage spark protection device for a regulated power supply as defined in claim 2, characterized in that: The high-frequency current transformer is used to collect real-time local discharge signals of the high-voltage output loop, specifically, the time of the active protection action is less than the local discharge time before high-voltage sparking.

4. A high voltage spark protection device for a regulated power supply as defined in claim 2, wherein: The digital processing unit is used to calculate and execute detection programs on the local discharge digital signals, specifically, the digital processing unit includes a derivative calculation detection subunit and an energy calculation detection subunit; the derivative calculation detection subunit is used to monitor the rising edge fluctuation of the current and generate a first detection signal S1; The energy calculation detection subunit is used to monitor the energy change fluctuation and generate a second detection signal S2; the S1 and S2 are sent to the protection execution unit respectively.

5. A high voltage spark protection device for a regulated power supply as defined in claim 4, characterized in that: The derivative calculation and detection subunit is used to monitor current rise-edge fluctuations. Specifically, it calculates the first derivative of the current, dI / dT, in real time and uses the first derivative with a set slope threshold T. S The comparison generates a first detection signal S1; the slope threshold T S Defined as background slope μ dI / dT With standard deviation σ dI / dT linear combination T S =μ dI / dt +k2σ dI / dt The value of k2 ranges from 4 to 12.

6. A high voltage spark protection device for a regulated power supply as defined in claim 4, wherein: The energy calculation detection subunit is used for monitoring energy change fluctuation, specifically: calculating the ratio R(t) = STA / LTA of the short-time energy average STA and the long-time energy average LTA, and comparing with a set ratio threshold T R to generate a second detection signal S2; the STA window length is 0.1 ms to 1 ms, and the LTA window length is 5 ms to 50 ms; wherein the threshold value of STA / LTA is in the range of 3 to 12.

7. A high voltage spark protection device for a regulated power supply as claimed in claim 5 or 6, characterized in that: When the S1 and S2 signals appear in a time window less than Δt, it is judged that the local discharge phenomenon occurs, and a protection signal Sp is output, Δt is the upper limit of the time length for judging local discharge, and its value range is 0.1ms to 5ms, which can be adjusted according to the working condition.

8. A high voltage spark protection device for a regulated power supply as defined in claim 4, wherein: The passive protection unit protects the ion source steady current power supply against the high-voltage sparking phenomenon without local discharge, specifically, the passive protection unit is sequentially provided with a first energy discharge module, a second common-mode suppression module and a third differential-mode suppression module; the first energy discharge module is used to bypass discharge the huge sparking energy to prevent the subsequent modules from being broken down; The second common-mode suppression module is used to suppress the common-mode noise in the high-frequency sparking signal; The third differential-mode suppression module is used to suppress the differential-mode noise in the high-frequency sparking signal; after filtering through the three modules, the high-voltage sparking energy is limited below the safety level, and the normal passing of the power frequency signal is not affected.

9. A high voltage spark protection device for a regulated power supply as defined in claim 8, wherein: The primary energy discharge module comprises a gas discharge tube (GDT) and a metal oxide varistor (MOV), the gas discharge tube (GDT) is connected in front of the metal oxide varistor (MOV), the gas discharge tube (GDT) is used for protecting the metal oxide varistor (GDT), and the metal oxide varistor (MOV) is used for discharging the striking energy; the secondary common mode suppression module comprises an anti-saturation inductor at the front end and a voltage stabilizing capacitor at the rear end, the anti-saturation inductor is used for suppressing the common mode noise, and the voltage stabilizing capacitor is used for providing a discharge path to the ground for the common mode noise; the saturation current of the anti-saturation inductor is higher than the rated current; and the tertiary differential mode suppression module comprises a ferrite magnetic bead inductor at the front end and a small-capacity high-frequency capacitor at the rear end, the ferrite magnetic bead inductor is used for suppressing the differential mode noise, and the small-capacity high-frequency capacitor is used for providing a discharge path for the differential mode noise.

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