High voltage pulser protection circuit and appliance

Abstract

The application relates to a high-voltage pulse generator protection circuit and an electrical appliance. The high-voltage pulse generator protection circuit comprises a second sampling circuit in the high-voltage pulse generator protection circuit, which is used for detecting an output current of a high-voltage pulse generator, providing a second detection voltage corresponding to the output current for a second protection circuit, providing the output current for a first sampling circuit through a protection switch, and providing a first detection voltage for a first protection circuit by the first sampling circuit. The second protection circuit and the first protection circuit judge abnormal conditions of the high-voltage pulse generator based on the second detection voltage and the first detection voltage respectively. When the second protection circuit determines that the high-voltage pulse generator appears abnormal conditions, the protection switch is turned off, at this time, there is no high-voltage pulse output, the protection purpose is achieved, and the problem of how to provide a protection function when the high-voltage pulse generator appears a fault is solved.

Description

Technical Field

[0001] This application relates to the field of high voltage pulse generator technology, and in particular to a high voltage pulse generator protection circuit and electrical equipment. Background Technology

[0002] After years of development, pulsed power technology has achieved significant results and has been widely applied in various fields, including military and civilian applications. In the medical field, pulsed ablation technology is gradually emerging. The core component of a pulsed ablation system is a high-voltage pulse generator, mostly based on solid-state switch designs, generally possessing high-voltage, high-current output characteristics. Because it directly affects the human body, the system has high safety requirements and needs to provide protection functions to cope with abnormal operating conditions. Currently, if the high-voltage pulse generator experiences controller failure or uncontrolled switching device damage, it may lead to uncontrolled output, causing serious consequences. Summary of the Invention

[0003] This application provides a high-voltage pulse generator protection circuit and electrical device to address how to provide protection when a high-voltage pulse generator malfunctions.

[0004] In a first aspect, this application provides a high-voltage pulse generator protection circuit, characterized in that the high-voltage pulse generator protection circuit includes a first sampling circuit, a second sampling circuit, a first protection circuit, and a second protection circuit. The input terminal of the second sampling circuit is connected to the output terminal of the high-voltage pulse generator. The output terminal of the second sampling circuit is connected to the input terminal of the second protection circuit and the first terminal of a protection switch. The output terminal of the second protection circuit is connected to the second terminal of the protection switch. The third terminal of the protection switch is connected to the input terminal of the first protection circuit via the first sampling circuit. The output terminal of the first protection circuit is connected to the input terminal of the high-voltage pulse generator.

[0005] The second sampling circuit is used to receive the output current of the high-voltage pulse generator and output a corresponding second detection voltage to the second protection circuit according to the output current; the second protection circuit determines the operating status of the high-voltage pulse generator according to the second detection voltage, and outputs a corresponding shutdown signal to the protection switch when the operating status is abnormal;

[0006] The first sampling circuit is used to transmit an output abnormal signal to the first protection circuit when the protection switch is off, and the first protection circuit controls the operating state of the high voltage pulse generator to switch to the off state according to the output abnormal signal; when the protection switch is on, it receives the output current provided by the second sampling circuit, and outputs a corresponding first detection voltage to the first protection circuit according to the output current; the first protection circuit determines the operating state of the high voltage pulse generator according to the first detection voltage, and controls the operating state of the high voltage pulse generator to switch to the off state when the operating state is abnormal.

[0007] Secondly, this application provides an electrical device, which includes a high-voltage pulse generator and a high-voltage pulse generator protection circuit as described above.

[0008] Compared with the prior art, the technical solution provided in this application has the following advantages: The high-voltage pulse generator protection circuit provided in this application includes a first sampling circuit, a second sampling circuit, a first protection circuit, and a second protection circuit. The input terminal of the second sampling circuit is connected to the output terminal of the high-voltage pulse generator. The output terminal of the second sampling circuit is connected to the input terminal of the second protection circuit and the first terminal of the protection switch. The output terminal of the second protection circuit is connected to the second terminal of the protection switch. The third terminal of the protection switch is connected to the input terminal of the first protection circuit through the first sampling circuit. The output terminal of the first protection circuit is connected to the input terminal of the high-voltage pulse generator. The second sampling circuit is used to receive the output current of the high-voltage pulse generator and output a corresponding second detection voltage according to the output current. The second protection circuit determines the operating state of the high-voltage pulse generator based on the second detection voltage, and outputs a corresponding shutdown signal to the protection switch when the operating state is abnormal. The first sampling circuit transmits an output abnormal signal to the first protection circuit when the protection switch is off, and the first protection circuit controls the operating state of the high-voltage pulse generator to switch to the off state based on the output abnormal signal. When the protection switch is on, the circuit receives the output current provided by the second sampling circuit and outputs a corresponding first detection voltage to the first protection circuit based on the output current. The first protection circuit determines the operating state of the high-voltage pulse generator based on the first detection voltage, and controls the operating state of the high-voltage pulse generator to switch to the off state when the operating state is abnormal.

[0009] The second sampling circuit in the aforementioned high-voltage pulse generator protection circuit detects the output current of the high-voltage pulse generator and provides a second detection voltage corresponding to the output current to the second protection circuit. It also provides the output current to the first sampling circuit via a protection switch, which in turn provides a first detection voltage to the first protection circuit. The second and first protection circuits determine the abnormal condition of the high-voltage pulse generator based on the second and first detection voltages, respectively. When the second protection circuit determines that an abnormal condition has occurred, it shuts off the protection switch, thus eliminating high-voltage pulse output and achieving the protection objective. Conversely, when the first protection circuit determines that an abnormal condition has occurred, it controls the high-voltage pulse generator to shut down, thereby achieving the protection objective. The first and second protection circuits operate independently. Whether a single protection circuit operates alone or both operate simultaneously, the protection objective is achieved. This prevents the high-voltage pulse generator from continuing to operate under abnormal conditions, which could lead to internal component failure or damage and uncontrolled operation. Furthermore, it prevents the high-voltage pulse generator from losing control and causing serious consequences, thus solving the problem of providing protection when a high-voltage pulse generator malfunctions. Attached Figure Description

[0010] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0011] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0013] Figure 1 A schematic diagram of a high-voltage pulse generator protection circuit provided in this application embodiment;

[0014] Figure 2 A partial structural schematic diagram of a high-voltage pulse generator protection circuit provided in an embodiment of this application;

[0015] Figure 3 This is a schematic diagram of the structure of a second protection circuit provided in an embodiment of this application;

[0016] Figure 4 A partial structural schematic diagram of a high-voltage pulse generator protection circuit provided in an embodiment of this application;

[0017] Figure 5 A schematic diagram of the working waveform of a high-voltage pulse generator provided in an embodiment of this application;

[0018] Figure 6 A schematic diagram of the working waveform of a high-voltage pulse generator protection circuit provided in this application embodiment;

[0019] Figure 7 This is a schematic diagram of the working waveform of a high-voltage pulse generator protection circuit provided in an embodiment of this application. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] The following disclosure provides numerous different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of the invention. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0022] In one embodiment, Figure 1 This is a schematic diagram of the structure of a high-voltage pulse generator protection circuit 200 in one embodiment, with reference to... Figure 1 The high-voltage pulse generator protection circuit 200 includes a first sampling circuit 240, a second sampling circuit 210, a first protection circuit 220, and a second protection circuit 230. The input terminal of the second sampling circuit 210 is connected to the output terminal of the high-voltage pulse generator 100. The output terminal of the second sampling circuit 210 is connected to the input terminal of the second protection circuit 230 and the first terminal of the protection switch Qp. The output terminal of the second protection circuit 230 is connected to the second terminal of the protection switch Qp. The third terminal of the protection switch Qp is connected to the input terminal of the first protection circuit 220 through the first sampling circuit 240. The output terminal of the first protection circuit 220 is connected to the input terminal of the high-voltage pulse generator 100.

[0023] The second sampling circuit 210 is used to receive the output current of the high voltage pulse generator 100, and output a corresponding second detection voltage to the second protection circuit 230 according to the output current; the second protection circuit 230 determines the operating state of the high voltage pulse generator 100 according to the second detection voltage, and outputs a corresponding shutdown signal to the protection switch Qp when the operating state is abnormal;

[0024] The first sampling circuit 240 is used to receive the output current provided by the second sampling circuit 210 through the protection switch Qp, and output a corresponding first detection voltage to the first protection circuit 220 according to the output current; the first protection circuit 220 determines the operating state of the high voltage pulse generator 100 according to the first detection voltage, and controls the operating state of the high voltage pulse generator 100 to switch to the off state when the operating state is abnormal.

[0025] Specifically, the second sampling circuit 210 collects the output current of the high-voltage pulse generator 100 and converts it into a corresponding second detection voltage. The second sampling circuit 210 outputs different second detection voltages depending on the output current, indicating a correspondence between the output current and the second detection voltage. The second protection circuit 230 can then perform anomaly detection based on the second detection voltage to determine if the high-voltage pulse generator 100 is malfunctioning. Different second detection voltages correspond to different operating states; that is, the second protection circuit 230 can determine whether the corresponding operating state is abnormal or normal based on the second detection voltage. Different operating states correspond to different on / off signals. When the operating state is normal, it outputs a corresponding normal conduction signal; conversely, when the operating state is abnormal, it outputs a corresponding off signal.

[0026] When the protection switch Qp is on, the first sampling circuit 240 can receive the output current transmitted from the second sampling circuit 210 through the protection switch Qp, and generate a corresponding first detection voltage based on the output current, which is then provided to the first protection circuit 220. The first protection circuit 220 uses the first detection voltage to determine the abnormal condition of the high-voltage pulse generator 100, and thus controls the operating state of the high-voltage pulse generator 100. When the protection switch Qp is off, the first sampling circuit 240 cannot receive the output current through the protection switch Qp, so the first detection voltage provided to the first protection circuit 220 is zero, and the first protection circuit 220 controls the high-voltage pulse generator 100 to turn off based on this first detection voltage.

[0027] The first protection circuit 220 and the second protection circuit 230 are independent of each other. Whether a single protection circuit operates alone or both protection circuits operate simultaneously, the protection purpose can be achieved. This prevents the high-voltage pulse generator 100 from continuing to work under abnormal conditions, which could lead to internal component failure or damage and uncontrolled operation. In turn, it prevents the high-voltage pulse generator 100 from losing control of its output and causing serious consequences. This solves the problem of how to provide protection when the high-voltage pulse generator 100 fails.

[0028] In one embodiment, the high-voltage pulse generator 100 includes a DC power supply, a control switch, and a pulse resistor. The control switch includes a first switch, a second switch, a third switch, and a fourth switch. The first switch and the third switch are connected in series, and the second switch and the fourth switch are connected in series. The connection point between the first switch and the second switch is connected to the positive terminal of the DC power supply. The connection point between the first switch and the third switch is also connected to the first end of the pulse resistor. The connection point between the second switch and the fourth switch is also connected to the second end of the pulse resistor. The connection point between the third switch and the fourth switch serves as the output terminal of the high-voltage pulse generator 100. The negative terminal of the DC power supply is grounded together with the first protection circuit 220 in the high-voltage pulse generator protection circuit 200.

[0029] Specifically, refer to Figure 2 The high-voltage pulse generator 100 specifically includes a DC power supply (HVDC), a control switch, and a pulse resistor (LOAD). The DC power supply is an adjustable high-voltage DC power supply. The control switch consists of four switches: a first switch (S1), a second switch (S2), a third switch (S3), and a fourth switch (S4). The first switch (S1) and the third switch (S3) are connected in series, as are the second switch (S2) and the fourth switch (S4). The connection point between the first switch (S1) and the second switch (S2) is connected to the positive terminal of the DC power supply. The connection point between the first switch (S1) and the third switch (S3) is also connected to the first terminal of the pulse resistor. The connection point between the second switch (S2) and the fourth switch (S4) is also connected to the second terminal of the pulse resistor. The connection point between the third switch (S3) and the fourth switch (S4) serves as the output terminal of the high-voltage pulse generator 100 and is connected to the input terminal of the second sampling circuit 210.

[0030] The high-voltage pulse is output from the pulse resistor and is generated by a specific combination of the switching states of four switches through the high-voltage DC voltage HVDC. The switching states of the four switches are controlled by the high-voltage pulse generator protection circuit 200, thereby controlling the working state of the high-voltage pulse generator 100 and providing protection for the high-voltage pulse generator 100.

[0031] In one embodiment, the second sampling circuit 210 includes a current transformer, a first diode, and a second detection resistor. The primary winding of the current transformer is connected to the output terminal of the high-voltage pulse generator 100, the secondary winding of the current transformer is connected to the positive terminal of the first diode, the negative terminal of the first diode is connected to the input terminal of the second protection circuit 230 and the first terminal of the second detection resistor, and the second terminal of the second detection resistor is grounded together with the secondary winding of the current transformer. The voltage across the second detection resistor is the second detection voltage.

[0032] Specifically, refer to Figure 2 The current transformer is denoted as CT1, the first diode as D1, and the second sensing resistor as Rcs2. The primary winding of the current transformer is connected to the output terminal of the high-voltage pulse generator 100 and the second protection circuit 230, respectively. The turns ratio of the secondary winding to the primary winding of the current transformer is Ns:Np = n:1, so the second sensing voltage across the second sensing resistor is... I OUT The output current corresponds to the output current, which is the output current of the DC power supply in the high-voltage pulse generator 100, and is a unidirectional current; I LOAD The current flowing through the pulse resistor is a bidirectional current; under normal circumstances, I... OUT and I LOAD Both have the same amplitude and width, I OUT isI LOAD The absolute value of Vcs2 and I LOAD They are positively correlated.

[0033] Reference Figure 5 It can be seen that when the first and fourth switches are closed and energized, the second and third switches are open and not energized, and the pulse voltage V on the integrating resistor LOAD is... LOAD If it is a positive value, then the pulse current I LOAD It is also a positive value, and the pulse current I OUT For I LOAD The absolute value; while when the second and third switches are closed and energized, the first and fourth switches are open and de-energized, and the pulse voltage V on the integrating resistor LOAD. LOAD If it is negative, then the pulse current I LOAD It is also a negative value, while the pulse current I OUT For I LOAD The absolute value of.

[0034] In one embodiment, such as Figure 3As shown, the second protection circuit 230 includes a current amplitude limiting circuit 231, a pulse width limiting circuit 232, and a driving circuit 233. The input terminals of the current amplitude limiting circuit 231 and the pulse width limiting circuit 232 are respectively connected to the output terminal of the second sampling circuit 210. The output terminals of the current amplitude limiting circuit 231 and the pulse width limiting circuit 232 are connected to the input terminal of the driving circuit 233. The output terminal of the driving circuit 233 is connected to the gate of the protection switch Qp. The drain of the protection switch Qp is connected to the primary winding of the current transformer. The source of the protection switch Qp is connected to the input terminal of the first sampling circuit 240.

[0035] The current amplitude limiting circuit 231 is used to output a shutdown signal to the protection switch Qp through the drive circuit 233 when the pulse current amplitude of the high voltage pulse generator 100 is abnormal.

[0036] The pulse width limiting circuit 232 is used to output a shutdown signal to the protection switch Qp through the drive circuit 233 when the pulse current pulse width of the high voltage pulse generator 100 is abnormal.

[0037] Specifically, the current amplitude limiting circuit 231 is used to determine whether the pulse current amplitude is abnormal based on the second detection voltage. When the pulse current amplitude is determined to be abnormal, the drive circuit 233 outputs a shutdown signal to the protection switch Qp. The pulse width limiting circuit 232 is used to determine whether the pulse current pulse width is abnormal based on the second detection voltage. When the pulse current pulse width is determined to be abnormal, the drive circuit 233 outputs a shutdown signal to the protection switch Qp.

[0038] Reference Figure 2The protection switch Qp is implemented using a high-voltage, high-current IGBT solid-state protection switch. The drain of the protection switch Qp is connected to the primary of the current transformer, the gate of the protection switch Qp is connected to the drive circuit 233, the source of the protection switch Qp is connected to the first sampling circuit 240, and the source of the protection switch Qp is also grounded to the negative terminal of the DC power supply through the second detection resistor. The protection switch Qp switches its state based on the signal provided by the drive circuit 233, thereby changing the detection result of the first sampling circuit 240 on the output current. When the protection switch Qp is closed, the first sampling circuit 240 receives the output current provided by the second sampling circuit through the protection switch Qp and converts the output current into a corresponding first detection voltage, which is then provided to the first protection circuit 220. The first protection circuit 220 determines the abnormal condition of the high-voltage pulse generator according to the first detection voltage (Vcs1) provided by the first sampling circuit 240. When the protection switch Qp is open, the first sampling circuit 240 cannot obtain the output current through the protection switch Qp. At this time, the first protection circuit 220 shuts down the high-voltage pulse generator 100, thereby achieving abnormal protection for the high-voltage pulse generator 100 and preventing the high-voltage pulse generator 100 from continuing to operate under abnormal conditions and causing device damage.

[0039] In one embodiment, the current amplitude limiting circuit 231 includes a first resistor, a second resistor, a first comparator, and a second diode. The first end of the first resistor is connected to the output terminal of the second sampling circuit 210, and the second end of the first resistor is connected to the negative terminal of the second diode and the non-inverting input terminal of the first comparator. The first end of the second resistor is used to receive a first reference voltage, and the second end of the second resistor is connected to the inverting input terminal of the first comparator. The output terminal of the first comparator is connected to the positive terminal of the second diode and the input terminal of the driving circuit 233.

[0040] Specifically, refer to Figure 3 The first resistor is R1, the second resistor is R2, the first comparator is U1, and the second diode is D2. (Refer to...) Figure 6 When the high-voltage pulse generator 100 is working normally, the pulse current I LOAD The voltage is lower, which makes the second detection voltage Vcs2 lower. The second detection voltage Vcs2 is lower than the first reference voltage Vref1. At this time, the output voltage V1 of the first comparator U1 is a low-level signal. The drive circuit 233 outputs a high-level signal to the protection switch Qp based on the received low-level signal. The protection switch Qp is in the on state based on the high-level signal.

[0041] Reference Figure 6 When the high-voltage pulse generator 100 is in an abnormal working state, the pulse current I LOADThe voltage is too high, causing the second detection voltage Vcs2 to be too high. The second detection voltage Vcs2 is higher than the first reference voltage Vref1. At this time, the output voltage V1 of the first comparator U1 flips to a high-level signal. At the same time, due to the positive feedback of the second diode D2, the non-inverting input terminal of the first comparator U1 continues to maintain a high voltage state (i.e., the input voltage of the non-inverting input terminal of the first comparator is higher than the first reference voltage Vref1). The output voltage V1 of the first comparator continues to maintain a high-level state. The drive circuit 233 outputs a low-level turn-off signal to the protection switch Qp based on the received high-level signal. The protection switch Qp changes from the on state to the off state. Then, the discharge circuit formed by the protection switch Qp and the primary of the current transformer changes from the on state to the off state. The output current of the high-voltage pulse generator 100 cannot be transmitted to the first sampling circuit 240 through the protection switch Qp, that is, the pulse output is cut off. The first protection circuit 220 controls the high-voltage pulse generator 100 to turn off based on the off protection switch Qp. Due to the positive feedback effect of the second diode D2, the circuit protection state is locked, preventing frequent connection of the discharge circuit after a fault, which could cause further damage.

[0042] In one embodiment, the pulse width limiting circuit 232 includes a third resistor, a fourth resistor, a second comparator, a non-inverting driver, a first field-effect transistor, a second field-effect transistor, an integrating resistor, an integrating capacitor, a fifth resistor, a sixth resistor, a third comparator, and a third diode. The first end of the third resistor is connected to the output of the second sampling circuit 210, and the second end of the third resistor is connected to the inverting input of the second comparator. The first end of the fourth resistor is used to receive a second reference voltage, and the second end of the fourth resistor is connected to the non-inverting input of the second comparator. The output of the second comparator is connected to the input of the non-inverting driver, and the output of the non-inverting driver is connected to the gate of the first field-effect transistor and the gate of the second field-effect transistor, respectively.

[0043] The gate of the first field-effect transistor is connected to the output terminal of the non-inverting driver and the gate of the second field-effect transistor, respectively. The drain of the first field-effect transistor is connected to the source terminal of the non-inverting driver via the same driving power supply. The source of the first field-effect transistor is connected to the drain of the second field-effect transistor and the first terminal of the integrating capacitor via the integrating resistor, respectively. The drain of the second field-effect transistor is connected to the second terminal of the integrating resistor, the first terminal of the sixth resistor, and the first terminal of the integrating capacitor, respectively. The source of the second field-effect transistor and the second terminal of the integrating capacitor are grounded together.

[0044] The first end of the fifth resistor is used to receive a third reference voltage. The second end of the fifth resistor is connected to the inverting input terminal of the third comparator. The first end of the sixth resistor is connected to the second end of the integrating resistor, the drain of the second field-effect transistor, and the first end of the integrating capacitor. The second end of the sixth resistor is connected to the non-inverting input terminal of the third comparator and the cathode of the third diode. The output terminal of the third comparator is connected to the input terminal of the driving circuit 233 and the anode of the third diode.

[0045] Specifically, referring to Figure 3 , the third resistor is R3, the fourth resistor is R4, the second comparator is U2, the non-inverting driver is U3, the first field-effect transistor is Q1, the second field-effect transistor is Q2, the integrating resistor is R CHG , the integrating capacitor is C CHG , the fifth resistor is R5, the sixth resistor is R6, the third comparator is U4, and the third diode is D3. When the high-voltage pulse generator 100 has no pulse output, the pulse current I OUT is 0, then the second detection voltage Vcs2 is 0, which is lower than the second reference voltage Vref2. At this time, the output voltage V3 of the second comparator U2 is a high-level signal, and the output voltage V4 of the non-inverting driver U3 is a high-level signal. At this time, the first field-effect transistor Q1 is turned off and the second field-effect transistor Q2 is turned on. The voltage V5 on the integrating capacitor C CHG is 0, and the output voltage V6 of the third comparator U4 is a low-level signal. The driving circuit 233 outputs a high-level signal to the protection switch Qp based on the low-level signal, and the protection switch Qp is turned on based on the high-level signal, so the discharge circuit is in an on state.

[0046] Referring to Figure 7 , when the high-voltage pulse generator 100 starts to output a pulse, the pulse current I OUT is positive, making the second detection voltage Vcs2 positive and higher than the second reference voltage Vref2. The output voltage V3 of the second comparator U2 flips to a low-level signal, and the output voltage V4 of the non-inverting driver U3 flips to a low-level signal. At this time, the first field-effect transistor Q1 is turned on and the second field-effect transistor Q2 is turned off. The VDD_S power supply charges the integrating capacitor C CHG in turn through the first field-effect transistor Q1 and the integrating resistor R CHG , and the voltage on the integrating capacitor C CHG (t is the pulse duration). At this time, there are two cases: (1) t < t0, indicating that t is short (normal operating state). When the pulse ends, the integrating capacitor C (t is the pulse duration). At this time, there are two cases: (1) t < t0, indicating that t is short (normal operating state). When the pulse ends, the integrating capacitor C CHGIf the voltage V5 is less than the third reference voltage Vref3, then the output voltage V6 of the third comparator U4 remains low. The drive circuit 233 outputs a high-level signal to the protection switch Qp based on the low-level signal. The protection switch Qp is turned on based on the high-level signal, so the discharge circuit is in the connected state. The first sampling circuit 240 can receive the output current through the turned-on protection switch Qp and generate a first detection voltage based on the output current to provide to the first protection circuit 220. The first protection circuit 220 controls the working state of the high-voltage pulse generator 100 based on the first detection voltage. (2) t≥t0 indicates that t is relatively long (abnormal working state). When the pulse ends, the integrating capacitor C CHG If the voltage V5 is higher than the third reference voltage Vref3, the output voltage V6 of the third comparator U4 flips to a high-level signal. Simultaneously, due to the positive feedback of the third diode D3, the non-inverting input of the third comparator U4 remains at a high voltage (i.e., the input voltage at the non-inverting input of the third comparator U4 remains higher than the third reference voltage Vref3). The output voltage V6 of the third comparator remains high. The drive circuit 233 outputs a low-level signal to the protection switch Qp based on the high-level signal. The protection switch Qp turns off based on the low-level signal, thus the discharge circuit is in the off state, and the pulse output is cut off. At this time, the pulse current I... OUT When the second detection voltage Vcs2 drops to 0, the first sampling circuit 240 cannot receive the output current through the protection switch Qp, thus causing the first protection circuit 220 to shut down the high-voltage pulse generator 100. However, due to the positive feedback effect of the third diode D3, the circuit protection state is locked, preventing frequent connection of the discharge circuit after a fault, which could cause further damage.

[0047] In one embodiment, the driving circuit 233 includes a fourth diode, a fifth diode, a seventh resistor, a transistor, an eighth resistor, and an isolation driver. The anode of the fourth diode is connected to the output terminal of the first comparator, the cathode of the fourth diode is connected to the first terminal of the seventh resistor and the cathode of the fifth diode, the anode of the fifth diode is connected to the output terminal of the third comparator, the second terminal of the seventh resistor is connected to the base of the transistor, the collector of the transistor is connected to the first terminal of the eighth resistor and the input terminal of the isolation driver, and the output terminal of the isolation driver is connected to the gate of the protection switch Qp.

[0048] Specifically, refer to Figure 3 and Figure 6 The fourth diode is D4, the fifth diode is D5, the seventh resistor is R7, the transistor is Q3, the eighth resistor is R8, and the isolation driver is U5. When the high-voltage pulse generator 100 malfunctions, the pulse current I... LOADIf the voltage is too high, meaning the second detection voltage Vcs2 is higher than the first reference voltage Vref1, the output voltage V1 of the first comparator U1 flips to a high level. At the same time, due to the positive feedback of D2, the non-inverting input of the first comparator U1 remains in a high voltage state, and V1 remains in a high level state. Transistor Q3 is turned on, causing the input voltage V2 of the isolation driver to flip to a low level, making the output voltage Vgate of the isolation driver low (VEE). The protection switch Qp is turned off, the discharge circuit is switched to the off state, and the pulse output is cut off.

[0049] Reference Figure 7 Because the pulse duration is relatively long, the voltage V5 on the integrating capacitor is higher than the third reference voltage Vref3 at the end of the pulse. Therefore, the output voltage V6 of the third comparator U4 flips to a high level. At the same time, due to the positive feedback effect of the third diode D3, the non-inverting input terminal of the third comparator U4 continues to maintain a high voltage state, so that V6 continues to maintain a high level state. Transistor Q3 is turned on, causing the input voltage V2 of the isolation driver to flip to a low level, so that the output voltage of the isolation driver is a low level (VEE). The protection switch Qp is turned off, the discharge circuit is switched to the off state, and the pulse output is cut off.

[0050] When transistor Q3 receives a low-level signal, it turns off, causing the input voltage V2 of the isolation driver to be a high-level signal and the output voltage Vgate of the isolation driver to be a high-level signal (VCC). The protection switch Qp turns on based on the received high-level signal, thus the discharge circuit is in the connected state, and the pulse output function is normal. Conversely, when transistor Q3 receives a high-level signal, it turns on, causing the input voltage V2 of the isolation driver to flip to a low-level signal and the output voltage Vgate of the isolation driver to be a low-level signal (VEE). The protection switch Qp hangs up based on the received low-level signal, thus the discharge circuit is in the off state, and the pulse output function is abnormal. Therefore, the first sampling circuit 240 cannot receive normal pulse current from the off protection switch Qp, thus detecting a shutdown signal from the off protection switch Qp and shutting down the high-voltage pulse generator 100 according to the shutdown signal. This prevents the high-voltage pulse generator 100 from continuing to operate under abnormal conditions, which could lead to device damage or other faults, and provides an abnormal protection function for the high-voltage pulse generator 100.

[0051] In one embodiment, the first sampling circuit 240 includes a first detection resistor, the first protection circuit 220 includes a controller, the first end of the first detection resistor and the input end of the controller are connected to the source of the protection switch Qp, the power supply end of the controller is connected to the DC power supply of the high voltage pulse generator 100, and the output end of the controller is connected to the control switch in the high voltage pulse generator 100.

[0052] Specifically, refer to Figure 2 and Figure 4 The first detection resistor is Rsc1, and the controller is U6. The first detection voltage (Vcs1) across the first detection resistor varies depending on the switching state of the protection switch Qp. When the protection switch Qp is in the on state, the first detection voltage Vcs1 is positive. The controller uses this first detection voltage to determine if the high-voltage pulse generator 100 has any abnormalities, such as abnormal pulse width, abnormal amplitude, or abnormal pulse timing. If the controller determines that the high-voltage pulse generator 100 is normal based on the first detection voltage, it controls the high-voltage pulse generator 100 to operate normally. If the controller determines that the high-voltage pulse generator 100 is abnormal based on the first detection voltage, it shuts down the high-voltage pulse generator 100. When the protection switch Qp is in the off state, the pulse output is cut off, and the first detection voltage Vcs1 is 0. Therefore, the controller cannot detect a valid first detection voltage and controls the high-voltage pulse generator 100 to shut down, providing an abnormal protection function for the high-voltage pulse generator 100.

[0053] In one embodiment, the high-voltage pulse generator protection circuit 200 further includes an auxiliary power supply circuit, which is connected to the second protection circuit 230 and is used to supply power to the second protection circuit 230.

[0054] Specifically, the auxiliary power supply circuit only supplies power to the second protection circuit 230, while the first protection circuit 220 is powered by the DC power supply in the high-voltage pulse generator 100. Therefore, the first protection circuit 220 and the second protection circuit 230 use different power supplies to achieve power supply isolation between the first protection circuit 220 and the second protection circuit 230, ensure that the two protection circuits operate independently, reduce the probability of both failing together, and improve system reliability.

[0055] In one embodiment, an electrical device is provided, the electrical device including a high-voltage pulse generator 100 and a high-voltage pulse generator protection circuit 200 as described in any of the above embodiments.

[0056] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also mean including the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof.

[0057] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A protection circuit for a high-voltage pulse generator, characterized in that, The high-voltage pulse generator protection circuit includes a first sampling circuit, a second sampling circuit, a first protection circuit, and a second protection circuit. The input terminal of the second sampling circuit is connected to the output terminal of the high-voltage pulse generator. The output terminal of the second sampling circuit is connected to the input terminal of the second protection circuit and the first terminal of the protection switch. The output terminal of the second protection circuit is connected to the second terminal of the protection switch. The third terminal of the protection switch is connected to the input terminal of the first protection circuit through the first sampling circuit. The output terminal of the first protection circuit is connected to the input terminal of the high-voltage pulse generator. The second sampling circuit is used to receive the output current of the high voltage pulse generator and output a corresponding second detection voltage to the second protection circuit according to the output current; The second protection circuit determines the operating status of the high-voltage pulse generator based on the second detection voltage, and outputs a corresponding shutdown signal to the protection switch when the operating status is abnormal. The first sampling circuit is used to receive the output current provided by the second sampling circuit through the protection switch, and output a corresponding first detection voltage to the first protection circuit according to the output current; The first protection circuit determines the operating state of the high-voltage pulse generator based on the first detection voltage, and controls the high-voltage pulse generator to switch to the off state when the operating state is abnormal.

2. The high-voltage pulse generator protection circuit according to claim 1, characterized in that, The second sampling circuit includes a current transformer, a first diode, and a second detection resistor. The primary winding of the current transformer is connected to the output terminal of the high-voltage pulse generator, and the secondary winding of the current transformer is connected to the positive terminal of the first diode. The negative terminal of the first diode is connected to the input terminal of the second protection circuit and the first terminal of the second detection resistor. The second terminal of the second detection resistor is grounded together with the secondary winding of the current transformer. The voltage across the second detection resistor is the second detection voltage.

3. The high-voltage pulse generator protection circuit according to claim 2, characterized in that, The second protection circuit includes a current amplitude limiting circuit, a pulse width limiting circuit, and a driving circuit. The input terminals of the current amplitude limiting circuit and the pulse width limiting circuit are respectively connected to the output terminal of the second sampling circuit. The output terminals of the current amplitude limiting circuit and the pulse width limiting circuit are connected to the input terminal of the driving circuit. The output terminal of the driving circuit is connected to the gate of the protection switch. The drain of the protection switch is connected to the primary winding of the current transformer. The source of the protection switch is connected to the input terminal of the first sampling circuit. The current amplitude limiting circuit is used to output a shutdown signal to the protection switch through the drive circuit when the pulse current amplitude of the high voltage pulse generator is abnormal. The pulse width limiting circuit is used to output a shutdown signal to the protection switch through the drive circuit when the pulse current pulse width of the high voltage pulse generator is abnormal.

4. The high-voltage pulse generator protection circuit according to claim 3, characterized in that, The current amplitude limiting circuit includes a first resistor, a second resistor, a first comparator, and a second diode. The first end of the first resistor is connected to the output of the second sampling circuit, and the second end of the first resistor is connected to the negative terminal of the second diode and the non-inverting input of the first comparator. The first end of the second resistor is used to receive a first reference voltage, and the second end of the second resistor is connected to the inverting input of the first comparator. The output of the first comparator is connected to the positive terminal of the second diode and the input of the driving circuit.

5. The high-voltage pulse generator protection circuit according to claim 4, characterized in that, The pulse width limiting circuit includes a third resistor, a fourth resistor, a second comparator, a non-inverting driver, a first field-effect transistor, a second field-effect transistor, an integrating resistor, an integrating capacitor, a fifth resistor, a sixth resistor, a third comparator, and a third diode. The first end of the third resistor is connected to the output of the second sampling circuit, and the second end of the third resistor is connected to the inverting input of the second comparator. The first end of the fourth resistor is used to receive a second reference voltage, and the second end of the fourth resistor is connected to the non-inverting input of the second comparator. The output of the second comparator is connected to the input of the non-inverting driver, and the output of the non-inverting driver is connected to the gate of the first field-effect transistor and the gate of the second field-effect transistor, respectively. The gate of the first field-effect transistor is connected to the output terminal of the non-inverting driver and the gate of the second field-effect transistor, respectively. The drain of the first field-effect transistor is connected to the source terminal of the non-inverting driver via the same driving power supply. The source of the first field-effect transistor is connected to the drain of the second field-effect transistor and the first terminal of the integrating capacitor via the integrating resistor, respectively. The drain of the second field-effect transistor is connected to the second terminal of the integrating resistor, the first terminal of the sixth resistor, and the first terminal of the integrating capacitor, respectively. The source of the second field-effect transistor and the second terminal of the integrating capacitor are grounded together. The first end of the fifth resistor is used to receive the third reference voltage. The second end of the fifth resistor is connected to the inverting input of the third comparator. The first end of the sixth resistor is connected to the second end of the integrating resistor, the drain of the second field-effect transistor, and the first end of the integrating capacitor. The second end of the sixth resistor is connected to the non-inverting input of the third comparator and the cathode of the third diode. The output of the third comparator is connected to the input of the driving circuit and the anode of the third diode.

6. The high-voltage pulse generator protection circuit according to claim 5, characterized in that, The driving circuit includes a fourth diode, a fifth diode, a seventh resistor, a transistor, an eighth resistor, and an isolation driver. The anode of the fourth diode is connected to the output terminal of the first comparator. The cathode of the fourth diode is connected to the first terminal of the seventh resistor and the cathode of the fifth diode. The anode of the fifth diode is connected to the output terminal of the third comparator. The second terminal of the seventh resistor is connected to the base of the transistor. The collector of the transistor is connected to the first terminal of the eighth resistor and the input terminal of the isolation driver. The output terminal of the isolation driver is connected to the gate of the protection switch.

7. The high-voltage pulse generator protection circuit according to claim 6, characterized in that, The first sampling circuit includes a first detection resistor, the first protection circuit includes a controller, the first end of the first detection resistor and the input end of the controller are connected to the source of the protection switch, the power supply end of the controller is connected to the DC power supply of the high voltage pulse generator, and the output end of the controller is connected to the control switch in the high voltage pulse generator.

8. The high-voltage pulse generator protection circuit according to claim 1, characterized in that, The high-voltage pulse generator protection circuit also includes an auxiliary power supply circuit, which is connected to the second protection circuit and is used to supply power to the second protection circuit.

9. An electrical appliance, characterized in that, The electrical equipment includes a high-voltage pulse generator and a high-voltage pulse generator protection circuit as described in any one of claims 1 to 8.

10. The electrical equipment according to claim 9, characterized in that, The high-voltage pulse generator includes a DC power supply, a control switch, and a pulse resistor. The control switch includes a first switch, a second switch, a third switch, and a fourth switch. The first switch and the third switch are connected in series, and the second switch and the fourth switch are connected in series. The connection point between the first switch and the second switch is connected to the positive terminal of the DC power supply. The connection point between the first switch and the third switch is also connected to the first end of the pulse resistor, and the connection point between the second switch and the fourth switch is also connected to the second end of the pulse resistor. The connection point between the third switch and the fourth switch serves as the output terminal of the high-voltage pulse generator. The negative terminal of the DC power supply is grounded together with the first protection circuit in the protection circuit of the high-voltage pulse generator.

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