Overvoltage suppression system and method in capacitor bank switching process
By using a vacuum laser-triggered switch to select and close the circuit near the voltage zero-crossing point, the problem of overvoltage during the switching of parallel capacitor banks is solved, thus achieving stable operation of the power grid and improving the safety of the equipment.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-15
- Publication Date
- 2026-03-20
AI Technical Summary
In existing technologies, parallel capacitor banks have significant overvoltage problems during switching, which can lead to equipment damage and unstable power grid operation, resulting in safety hazards and economic losses.
A vacuum laser-triggered switch is used to select phases for closing near the voltage zero-crossing point. Combined with an intelligent phase control module and a detection module, the switching process of the capacitor bank is precisely controlled to suppress or eliminate overvoltage.
It effectively suppresses or eliminates overvoltage during capacitor bank switching, improves grid stability and safety, extends equipment life, and is suitable for frequent switching scenarios.
Smart Images
Figure CN121710221A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of overvoltage suppression technology, specifically to an overvoltage suppression system and method during capacitor bank switching. Background Technology
[0002] The distribution network, located at the end of the power grid, is responsible for distributing electrical energy. To ensure efficient energy utilization and power quality, the distribution network needs to maintain a qualified voltage level. Reactive power compensation equipment is one of the key means to achieve this goal. By improving the power factor and stabilizing the grid voltage level, it can effectively improve power quality. A parallel capacitor bank is a device that connects power capacitors in parallel to the circuit. It typically includes components such as capacitors, reactance, protection devices, and switching switches. Due to its high cost-effectiveness and simple installation and commissioning, parallel capacitor banks have become the most widely used reactive power compensation device in medium-voltage distribution systems. Power capacitors themselves have advantages such as large capacity and low cost, and are widely used in the field of power quality improvement.
[0003] Currently, most parallel capacitor banks use a three-phase simultaneous switching method, which presents significant overvoltage problems during operation. This switching method causes large voltage surges when the power capacitors are connected to or disconnected from the grid, not only reducing the lifespan of the power capacitors but also potentially threatening the safe operation of the parallel capacitor bank and other grid equipment. The overvoltage phenomenon is particularly severe when switching large-capacity parallel capacitor banks. Frequent overvoltage events can lead to equipment damage and grid instability, causing numerous safety hazards and economic losses to the power system.
[0004] Therefore, how to effectively suppress the overvoltage generated during the switching of capacitor banks is a technical problem that urgently needs to be solved. Summary of the Invention
[0005] This application provides an overvoltage system and method during capacitor bank switching, which can solve the technical problem that there is significant overvoltage in parallel capacitor banks during switching, which poses a safety hazard to the power system.
[0006] In a first aspect, embodiments of this application provide an overvoltage suppression system during capacitor bank switching, the overvoltage suppression system during capacitor bank switching includes: a detection module, an intelligent phase control module, and a vacuum laser trigger switch; The detection module is used to collect voltage signals from the power distribution network, determine the zero-crossing position of the voltage signals, and send the zero-crossing position to the intelligent phase control module. The intelligent phase control module is used to control the vacuum laser trigger switch to close within a preset phase angle interval before or after the zero-crossing position, so as to connect the capacitor bank to the power distribution network.
[0007] In conjunction with the first aspect, in one embodiment, the vacuum laser trigger switch includes: an insulating shell, a laser irradiation window, a metal shield, a main electrode, and a trigger electrode; The metal shield, main electrode, and trigger electrode are disposed inside the insulating housing; The main electrode includes a cathode and an anode, the cathode and the anode are separated by a first preset distance, and the trigger electrode is disposed between the cathode and the anode; The metal shield is fitted over the cathode, anode and trigger electrode; The laser irradiation window and the trigger electrode are coaxially disposed on the insulating shell.
[0008] In conjunction with the first aspect, in one embodiment, the system further includes an excitation module, which includes a power supply, a laser, a beam splitter, and a focusing lens; The intelligent phase control module is also used to control the power supply to power the laser, so that the laser emits laser pulses, and then the laser pulses pass through the beam splitter and focusing lens, and irradiate the trigger electrode through the laser irradiation window, triggering the vacuum laser trigger switch to turn on and close.
[0009] In conjunction with the first aspect, in one embodiment, the system further includes: a pole-mounted circuit breaker connected in parallel with the vacuum laser trigger switch; The intelligent phase control module is also used to control the pole-mounted circuit breaker to close after controlling the vacuum laser trigger switch to close, at a preset time interval.
[0010] In conjunction with the first aspect, in one embodiment, the detection module is further configured to: The voltage signal of the power distribution network is collected according to a preset sampling frequency; Determine whether the positive and negative signs of the voltage signals at any two adjacent sampling points are opposite; The zero-crossing point position is calculated based on the sampling time coordinates and corresponding voltage values of two adjacent sampling points with opposite positive and negative values of the voltage signal.
[0011] In conjunction with the first aspect, in one implementation, the detection module is further configured to, according to the formula:
[0012] Calculate the zero-crossing position, where To pass through the zero point, This represents the sampling time coordinate of the preceding sampling point among two adjacent sampling points of the voltage signal with opposite signs. The sampling time coordinate of the next sampling point. This is the voltage value of the previous sampling point. This is the voltage value at the next sampling point.
[0013] In conjunction with the first aspect, in one embodiment, the detection module is further configured to: After collecting voltage signals from the distribution network according to a preset sampling period, the collected voltage signals are low-pass filtered to remove noise before determining whether the positive and negative signs of the voltage signals at two adjacent sampling points are opposite. Secondly, embodiments of this application provide a method for suppressing overvoltage during capacitor bank switching, the method comprising: The voltage signal of the power distribution network is acquired by the detection module, the zero-crossing position of the voltage signal is determined, and the zero-crossing position is sent to the intelligent phase control module. The intelligent phase control module controls the vacuum laser trigger switch to close within a preset phase angle range before or after the zero-crossing position, so as to connect the capacitor bank to the power distribution network.
[0014] In conjunction with the second aspect, in one embodiment, after the vacuum laser trigger switch is closed within a preset phase angle interval before or after the zero-crossing position by the intelligent phase control module, the method further includes: The intelligent phase control module controls the closing of the pole-mounted circuit breaker connected in parallel with the vacuum laser trigger switch.
[0015] In conjunction with the second aspect, in one implementation, the step of acquiring the voltage signal of the distribution network through the detection module and determining the zero-crossing position of the voltage signal includes: The detection module acquires the voltage signal of the power distribution network at a preset sampling frequency. Determine whether the positive and negative signs of the voltage signals at any two adjacent sampling points are opposite; The zero-crossing point position is calculated based on the sampling time coordinates and corresponding voltage values of two adjacent sampling points with opposite positive and negative values of the voltage signal. This application provides a system and method for suppressing overvoltage during capacitor bank switching. The system includes a detection module, an intelligent phase control module, and a vacuum laser trigger switch. The detection module is used to collect voltage signals from the distribution network, determine the zero-crossing position of the voltage signals, and send the zero-crossing position to the intelligent phase control module. The intelligent phase control module is used to control the vacuum laser trigger switch to close within a preset phase angle interval before or after the zero-crossing position, so as to connect the capacitor bank to the distribution network. By using a vacuum laser trigger switch to select and close the circuit near the voltage zero-crossing point, the overvoltage generated during the switching of substation capacitor banks can be effectively suppressed or even eliminated, thereby reducing the safety hazards caused by overvoltage to the power system and ensuring the stable operation of the power grid. Attached Figure Description
[0016] Figure 1 This is a functional module diagram of an embodiment of the overvoltage suppression system during capacitor bank switching in this application; Figure 2 This is a schematic diagram of the vacuum laser trigger switch of this application; Figure 3 This is a schematic diagram of the functional modules of the activation module in this application; Figure 4 This is a schematic flowchart of an embodiment of the method for suppressing overvoltage during capacitor bank switching in this application. Detailed Implementation
[0017] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.
[0018] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.
[0019] In a first aspect, embodiments of this application provide an overvoltage suppression system during capacitor bank switching.
[0020] In one embodiment, reference is made to Figure 1 , Figure 1 This is a flowchart illustrating the first embodiment of the overvoltage suppression system during capacitor bank switching in this application.
[0021] like Figure 1As shown, the overvoltage suppression system during capacitor bank switching includes: a detection module, an intelligent phase control module, and a vacuum laser trigger switch.
[0022] The detection module is used to collect voltage signals from the power distribution network, determine the zero-crossing position of the voltage signals, and send the zero-crossing position to the intelligent phase control module.
[0023] The intelligent phase control module is used to control the vacuum laser trigger switch to close within a preset phase angle interval before or after the zero-crossing position, so as to connect the capacitor bank to the power distribution network.
[0024] The detection module can be installed on the busbar of the distribution network to collect the voltage signal of the busbar and calculate the zero-crossing point based on the collected voltage signal. The detection module and the intelligent line control module can be connected via a communication line, and the detection module sends the zero-crossing point position to the intelligent detection module through the communication line.
[0025] In one embodiment, the detection module is further configured to: acquire voltage signals of the power distribution network at a preset sampling frequency; determine whether the positive and negative values of the voltage signals of two adjacent sampling points are opposite; and calculate the zero-crossing position based on the sampling time coordinates and corresponding voltage values of two adjacent sampling points with opposite positive and negative voltage signals.
[0026] It's worth noting that the sampling points here refer to the results of the detection module periodically sampling the voltage signal, taking one point at regular intervals. For example, if the sampling frequency is fs = 1000 Hz, then the sampling interval is Δt = 1 / fs = 1 ms, and the time coordinate of each sampling point is tn = n. 0.001 seconds. For two adjacent sampling points, if the positive and negative signs of the acquired voltage signals are opposite, then the zero-crossing point is determined to exist between these two sampling points.
[0027] As a preferred real-time method, a low-pass filter can be set in the detection module. After the detection module collects the voltage signal of the distribution network according to the preset sampling period, before judging whether the positive and negative signs of the voltage signals of two adjacent sampling points are opposite, the low-pass filter in the detection module performs low-pass filtering on the collected voltage signal to remove noise in the collected voltage signal, thereby ensuring the accuracy of subsequent zero-crossing position calculation.
[0028] As an example, for two adjacent sampling points (x0, y0) and (x1, y1) with opposite signs of a voltage signal, construct a linear equation: Assuming the function between the two points is a straight line, and the voltage value is 0 at the zero point, solve the equation y=0. The constructed equation is:
[0029] Calculate the zero-point position using the formula:
[0030] in, To pass through the zero point, This represents the sampling time coordinate of the preceding sampling point among two adjacent sampling points of the voltage signal with opposite signs. The sampling time coordinate of the next sampling point. This is the voltage value of the previous sampling point. This is the voltage value at the next sampling point.
[0031] It is worth noting that when the intelligent phase control module controls the vacuum laser trigger switch to close within a preset phase angle interval before or after the zero-crossing position, the preset phase angle interval can be set according to the actual situation of the power distribution network. In this application, the preset phase angle interval is set to 10 to 30 degrees before or after the zero-crossing point. The intelligent phase control module can control the vacuum laser trigger switch to close at an appropriate time based on the preset phase angle interval and the action time of the vacuum laser trigger switch.
[0032] In one embodiment, such as Figure 2 As shown, the vacuum laser trigger switch includes: an insulating shell, a laser irradiation window, a metal shield, a main electrode, and a trigger electrode.
[0033] The metal shield, main electrode, and trigger electrode are housed inside an insulating shell. The insulating shell maintains the vacuum level inside the vacuum laser trigger switch below a preset pressure value; in this embodiment, the vacuum level inside the vacuum laser trigger switch tube is maintained at 1×10⁻⁶. Below 5 Pa, the insulating shell serves both as insulation and support.
[0034] The main electrode includes a cathode and an anode, which are separated by a first preset distance L. The trigger electrode is disposed between the cathode and the anode. In this embodiment, the trigger electrode is disposed closer to the cathode.
[0035] A metal shield is fitted over the cathode, anode, and trigger electrode. The metal shield is made of copper and is used to adjust the electric field structure within the vacuum laser trigger switch. It also prevents metal vapor generated during arcing from depositing on the inner surface of the insulating housing, thus avoiding a decrease in insulation performance due to vapor deposition.
[0036] The laser irradiation window is coaxially arranged on the insulating shell with the trigger electrode. The function of the laser irradiation window is to ensure that the pulsed laser can irradiate the trigger electrode, while maintaining the vacuum inside the vacuum laser trigger switch, and also to provide insulation and support.
[0037] In one embodiment, such as Figure 3As shown, the system also includes an excitation module, which includes a power supply, a laser, a beam splitter, and a focusing lens. The intelligent phase control module is further used to control the power supply to power the laser, so that the laser emits laser pulses, and then the laser pulses pass through the beam splitter and focusing lens, and irradiate the trigger electrode through the laser irradiation window, triggering the vacuum laser trigger switch to turn on and close.
[0038] Explained, a beam splitter is used to divide the laser pulse emitted by a laser into multiple beams, each of which can illuminate different positions on the trigger electrode, enabling multi-point triggering and improving the reliability and uniformity of triggering. A focusing lens is used to focus the laser pulse onto the surface of the trigger electrode, concentrating the laser energy in a very small area, generating high energy density, and thus more effectively exciting the trigger electrode to generate initial plasma. A focusing lens also ensures that the laser beam precisely illuminates a specific position on the trigger electrode, improving the accuracy and consistency of triggering.
[0039] When a laser pulse irradiates the trigger electrode, the laser pulse interacts with the trigger electrode material during laser triggering, generating initial plasma on the electrode surface. This initial plasma, under the influence of an electric field, accelerates towards the cathode and anode. During this motion, energy accumulates, impacting the main electrode surface and generating metal ions, electrons, atoms, and metal vapor. This process continues, generating sufficient plasma to form the main gap arc channel, prompting the vacuum laser trigger switch to conduct and discharge.
[0040] It is worth noting that when the laser is focused on the surface of the trigger electrode, a high-temperature plasma is instantly generated, ionizing the metal vapor to form a conductive channel. The high current carrying capacity of the main electrode directly affects the plasma expansion rate and channel stability. If the conductivity of the main electrode is insufficient, it may cause the plasma channel to shrink or be interrupted, leading to a risk of switch conduction delay or current cutoff. Therefore, the design of the main electrode structure has a significant impact on the performance of the vacuum laser trigger switch. When a large current passes through, the electrode surface may undergo micro-area melting due to Joule heating and arcing. By optimizing the electrode geometry (such as increasing the contact area and adopting a ring-shaped multi-contact structure) and surface treatment (silver plating or sintered tungsten-copper composite material), the ablation rate can be reduced. Furthermore, in this embodiment, by setting a compact layout of the main electrode (coaxial or planar structure), the loop inductance can be reduced, allowing the current rise rate to meet the requirements of high-frequency pulses.
[0041] Explained, traditional vacuum circuit breakers are mechanical switches, and their operating mechanisms (such as springs and permanent magnet mechanisms) inherently exhibit mechanical dispersion. This means that even if the intelligent phase control module issues extremely precise closing commands, the inertia, lubrication, and wear of the mechanical moving parts can cause millisecond-level or even larger errors between the actual closing time and the expected closing point. Such errors are fatal for scenarios requiring zero-crossing switching with microsecond-level precision, severely affecting the effectiveness of phase selection and resulting in limited and unstable overvoltage suppression capabilities.
[0042] This application employs a vacuum laser-triggered switch for phase selection and closing near the voltage zero-crossing point. A laser pulse triggers the ionization of the dielectric within the vacuum chamber, thereby achieving conduction and switching off. This process involves almost no mechanical movement, and its action time dispersion can be controlled at the nanosecond to microsecond level, achieving a precision several orders of magnitude higher than that of a vacuum circuit breaker. This effectively suppresses or even eliminates overvoltages generated during the switching of substation capacitor banks, thereby reducing the safety hazards posed by overvoltages to the power system and ensuring stable grid operation.
[0043] This embodiment uses a vacuum laser-triggered switch as the switching switch for the capacitor bank. The principle is that a pulsed laser irradiates the trigger electrode of the vacuum laser-triggered switch, exciting a small amount of initial plasma. Under the strong electric field of the switch, the plasma particles accelerate and collide with each other, generating a large number of free electrons and ions, thus turning on the switch. The effect is that the vacuum laser-triggered switch induces ionization of the electrode material through laser, instantaneously generating a plasma channel in a vacuum, achieving rapid switching on and off of the high-voltage circuit. It combines the advantages of high withstand voltage, fast switching, and precise control. Therefore, compared to traditional vacuum circuit breakers, the effect of using a vacuum laser-triggered switch in this embodiment is improved from "possibly suppressing some overvoltage but with unstable effect" to "effectively suppressing or even eliminating overvoltage," achieving a qualitative leap in technical performance.
[0044] Furthermore, after the intelligent phase control module controls the vacuum laser trigger switch to close, it controls the pole-mounted circuit breaker connected in parallel with the vacuum laser trigger switch to close after a preset time interval.
[0045] In this embodiment, the preset duration can be flexibly set according to specific needs to optimize system performance. In this embodiment, the preset duration is set to 20 milliseconds. By setting a pole-mounted circuit breaker in parallel with the vacuum laser trigger switch, and configuring the pole-mounted circuit breaker to close only after the vacuum laser trigger switch has completed its closing operation, the pole-mounted circuit breaker can effectively shunt current after closing. This design can prevent the laser switch circuit from overloading due to excessive current when the vacuum laser trigger switch closes, thereby avoiding damage to the vacuum laser trigger switch and significantly improving the safety and reliability of the capacitor bank when connected to the power distribution network.
[0046] It is worth noting that this application achieves phase-controlled closing by precisely controlling the vacuum laser-triggered switch to close within a preset phase angle range. Simultaneously, by setting the pole-mounted circuit breaker to delay closing after the vacuum laser-triggered switch closes, the switch is effectively protected from overcurrent damage, thus extending the device's service life. Through the phase-selective closing operation of the vacuum laser-triggered switch, overvoltages generated during the switching process of substation capacitor banks can be effectively suppressed or even eliminated, significantly improving system stability and safety.
[0047] Furthermore, after the pole-mounted circuit breaker is closed, when the detected voltage signal is lower than a preset voltage threshold, the detection module sends an opening indication signal to the intelligent phase control module. The intelligent phase control module then controls the vacuum laser-triggered switch and the pole-mounted circuit breaker to open sequentially based on the opening indication signal. This mechanism ensures that when the voltage is below the threshold, the connection between the capacitor bank and the power grid is promptly disconnected, preventing equipment damage or other safety issues caused by low voltage. Simultaneously, it protects the vacuum laser-triggered switch and the pole-mounted circuit breaker from overcurrent damage, ensuring the safe operation of the system and extending the equipment's lifespan.
[0048] The capacitor bank switching overvoltage suppression system provided in this application proposes and implements a specific system architecture capable of perfectly executing the "phase selection and closing" command. This architecture creatively employs a vacuum laser-triggered switch as the actuating element, forming an ultra-high precision closed-loop control system with a detection module and an intelligent phase control module. Utilizing the extremely short action time and minimal dispersion of laser triggering technology, the electrical signal command issued by the intelligent phase control module controls the laser to emit light pulses. These light pulses travel at the speed of light and trigger the switch action. The delay in this process is fixed and negligible, allowing for precise compensation. Laser triggering achieves nanosecond-level synchronization accuracy for opening and closing, enabling the closing point to be strictly controlled within a preset, extremely narrow phase angle range (e.g., within ±1° electrical angle), fundamentally eliminating operational overvoltages caused by the uncertainty of the switch's own action.
[0049] Furthermore, this solution achieves a leap from overvoltage suppression to elimination. Due to the order-of-magnitude improvement in closing accuracy, the technical effects of this invention surpass conventional vacuum circuit breaker solutions. It no longer simply "suppresses" or "reduces" overvoltage, but rather, under ideal conditions, it can largely eliminate transient processes, thereby almost completely eliminating operational overvoltage. This will greatly improve the safety and stability of power systems, especially distribution networks, extend the service life of capacitor banks and other electrical equipment, reduce maintenance costs, and is a concrete realization of the "flexible" and "intelligent" requirements of smart grid switching operations.
[0050] Meanwhile, the overvoltage suppression system during capacitor bank switching in this application provides a solution for scenarios with frequent switching. Vacuum laser-triggered switches, in addition to high precision, typically feature long lifespan and frequent operation capability, while the mechanical lifespan of mechanical vacuum circuit breakers limits their operational frequency. This makes the solution in this application particularly suitable for applications requiring frequent reactive power compensation (such as industrial sites with rapidly changing loads, such as new energy power plants, electric arc furnaces, and rolling mills). In these scenarios, this invention not only offers superior performance but also higher economy and reliability, which is unmatched by conventional vacuum circuit breaker solutions.
[0051] Therefore, it can be seen that using vacuum laser-triggered switches to select phases for closing near the voltage zero-crossing point can effectively suppress or even eliminate overvoltages generated when switching substation capacitor banks, thereby reducing the safety hazards of overvoltages to the power system and ensuring the stable operation of the power grid.
[0052] Secondly, embodiments of this application also provide an overvoltage suppression system during capacitor bank switching.
[0053] In one embodiment, reference is made to Figure 4 , Figure 4 This is a schematic flowchart illustrating an embodiment of the overvoltage suppression method during capacitor bank switching according to this application. Figure 4 As shown, the method for suppressing overvoltage during capacitor bank switching includes the following steps: Step S101: Collect the voltage signal of the power distribution network through the detection module, determine the zero-crossing position of the voltage signal, and send the zero-crossing position to the intelligent phase control module; Step S102: Control the vacuum laser trigger switch to close within a preset phase angle interval before or after the zero-crossing position through the intelligent phase control module, so as to connect the capacitor bank to the power distribution network.
[0054] Furthermore, in one embodiment, the vacuum laser trigger switch includes: an insulating shell, a laser irradiation window, a metal shield, a main electrode, and a trigger electrode; The metal shield, main electrode, and trigger electrode are disposed inside the insulating housing; The main electrode includes a cathode and an anode, the cathode and the anode are separated by a first preset distance, and the trigger electrode is disposed between the cathode and the anode; The metal shield is fitted over the cathode, anode and trigger electrode; The laser irradiation window and the trigger electrode are coaxially disposed on the insulating shell.
[0055] Furthermore, in one embodiment, the method further includes: The intelligent phase control module controls the power supply to power the laser, causing the laser to emit laser pulses. These laser pulses then pass through the beam splitter and focusing lens, and through the laser irradiation window to irradiate the trigger electrode, triggering the vacuum laser trigger switch to close.
[0056] Furthermore, in one embodiment, after the vacuum laser trigger switch is closed within a preset phase angle interval before or after the zero-crossing position by the intelligent phase control module, the method further includes: The intelligent phase control module controls the closing of the pole-mounted circuit breaker connected in parallel with the vacuum laser trigger switch.
[0057] Further, in one embodiment, the step of acquiring the voltage signal of the distribution network through the detection module and determining the zero-crossing position of the voltage signal includes: The detection module acquires the voltage signal of the power distribution network at a preset sampling frequency. Determine whether the positive and negative signs of the voltage signals at any two adjacent sampling points are opposite; The zero-crossing point position is calculated based on the sampling time coordinates and corresponding voltage values of two adjacent sampling points with opposite positive and negative values of the voltage signal.
[0058] Furthermore, in one embodiment, the method further includes, according to the formula:
[0059] Calculate the zero-crossing position, where To pass through the zero point, This represents the sampling time coordinate of the preceding sampling point among two adjacent sampling points of the voltage signal with opposite signs. The sampling time coordinate of the next sampling point. This is the voltage value of the previous sampling point. This is the voltage value at the next sampling point.
[0060] Furthermore, in one embodiment, after the voltage signal of the distribution network is acquired by the detection module according to a preset sampling period, before determining whether the positive and negative signs of the voltage signals of two adjacent sampling points are opposite, the method further includes: The detection module performs low-pass filtering on the acquired voltage signal to remove noise from the acquired voltage signal.
[0061] The implementation of each step in the above-mentioned method for suppressing overvoltage during capacitor bank switching corresponds to each step in the above-mentioned system embodiment for suppressing overvoltage during capacitor bank switching. Their functions and implementation processes will not be described in detail here.
[0062] It should be noted that the sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.
[0063] The terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus. The terms "first," "second," and "third," etc., are used to distinguish different objects, etc., and do not indicate a sequence, nor do they limit "first," "second," and "third" to different types.
[0064] In the description of the embodiments of this application, terms such as "exemplary," "for example," or "for instance" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as "exemplary," "for example," or "for instance" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary," "for example," or "for instance" is intended to present the relevant concepts in a concrete manner.
[0065] In the description of the embodiments of this application, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. The "and / or" in the text is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of this application, "multiple" means two or more.
[0066] In some processes described in the embodiments of this application, multiple operations or steps are included in a specific order. However, it should be understood that these operations or steps may not be executed in the order they appear in the embodiments of this application, or they may be executed in parallel. The sequence number of the operation is only used to distinguish different operations, and the sequence number itself does not represent any execution order. In addition, these processes may include more or fewer operations, and these operations or steps may be executed sequentially or in parallel, and these operations or steps may be combined.
[0067] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes several instructions to cause a terminal device to execute the methods described in the various embodiments of this application.
[0068] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.
Claims
1. A system for suppressing overvoltage during capacitor bank switching, characterized in that, The overvoltage suppression system during capacitor bank switching includes: a detection module, an intelligent phase control module, and a vacuum laser trigger switch; The detection module is used to collect voltage signals from the power distribution network, determine the zero-crossing position of the voltage signals, and send the zero-crossing position to the intelligent phase control module. The intelligent phase control module is used to control the vacuum laser trigger switch to close within a preset phase angle interval before or after the zero-crossing position, so as to connect the capacitor bank to the power distribution network.
2. The overvoltage suppression system during capacitor bank switching as described in claim 1, characterized in that, The vacuum laser trigger switch includes: an insulating shell, a laser irradiation window, a metal shield, a main electrode, and a trigger electrode; The metal shield, main electrode, and trigger electrode are disposed inside the insulating housing; The main electrode includes a cathode and an anode, the cathode and the anode are separated by a first preset distance, and the trigger electrode is disposed between the cathode and the anode; The metal shield is fitted over the cathode, anode and trigger electrode; The laser irradiation window and the trigger electrode are coaxially disposed on the insulating shell.
3. The overvoltage suppression system during capacitor bank switching as described in claim 2, characterized in that, The system also includes an excitation module, which comprises a power supply, a laser, a beam splitter, and a focusing lens; The intelligent phase control module is also used to control the power supply to power the laser, so that the laser emits laser pulses, and then the laser pulses pass through the beam splitter and focusing lens, and irradiate the trigger electrode through the laser irradiation window, triggering the vacuum laser trigger switch to turn on and close.
4. The overvoltage suppression system during capacitor bank switching as described in claim 1, characterized in that, The system also includes: a pole-mounted circuit breaker connected in parallel with the vacuum laser trigger switch; The intelligent phase control module is also used to control the pole-mounted circuit breaker to close after controlling the vacuum laser trigger switch to close, at a preset time interval.
5. The overvoltage suppression system during capacitor bank switching as described in claim 1, characterized in that, The detection module is also used for: The voltage signal of the power distribution network is collected according to a preset sampling frequency; Determine whether the positive and negative signs of the voltage signals at any two adjacent sampling points are opposite; The zero-crossing point position is calculated based on the sampling time coordinates and corresponding voltage values of two adjacent sampling points with opposite positive and negative values of the voltage signal.
6. The overvoltage suppression system during capacitor bank switching as described in claim 5, characterized in that, The detection module is also used to, according to the formula: Calculate the zero-crossing position, where To pass through the zero point, This represents the sampling time coordinate of the preceding sampling point among two adjacent sampling points of the voltage signal with opposite signs. The sampling time coordinate of the next sampling point. This is the voltage value of the previous sampling point. This is the voltage value at the next sampling point.
7. The overvoltage suppression system during capacitor bank switching as described in claim 1, characterized in that, The detection module is also used for: After collecting voltage signals from the distribution network according to a preset sampling period, the collected voltage signals are low-pass filtered to remove noise before determining whether the positive and negative signs of the voltage signals at two adjacent sampling points are opposite.
8. A method for suppressing overvoltage during capacitor bank switching, characterized in that, The overvoltage suppression method during capacitor bank switching includes: The voltage signal of the power distribution network is acquired by the detection module, the zero-crossing position of the voltage signal is determined, and the zero-crossing position is sent to the intelligent phase control module. The intelligent phase control module controls the vacuum laser trigger switch to close within a preset phase angle range before or after the zero-crossing position, so as to connect the capacitor bank to the power distribution network.
9. The method for suppressing overvoltage during capacitor bank switching as described in claim 8, characterized in that, After the vacuum laser trigger switch is closed within a preset phase angle interval before or after the zero-crossing position by the intelligent phase control module, the system further includes: The intelligent phase control module controls the closing of the pole-mounted circuit breaker connected in parallel with the vacuum laser trigger switch.
10. The method for suppressing overvoltage during capacitor bank switching as described in claim 9, characterized in that, The step of acquiring voltage signals from the power distribution network through a detection module and determining the zero-crossing position of the voltage signals includes: The detection module acquires the voltage signal of the power distribution network at a preset sampling frequency. Determine whether the positive and negative signs of the voltage signals at any two adjacent sampling points are opposite; The zero-crossing point position is calculated based on the sampling time coordinates and corresponding voltage values of two adjacent sampling points with opposite positive and negative values of the voltage signal.