A high-voltage pulse power discharge module structure
Patent Information
- Application Number
- CN202522388393.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-11
- Publication Date
- 2026-11-03
- Estimated Expiration
- 2035-11-11
AI Technical Summary
Existing pulse power supply structures, due to their discrete, long-distance layout and unreasonable bus design, result in large stray inductance in the system circuits, making it difficult to meet the requirements of high-power applications for pulse leading edge, delay, and waveform quality.
The common anode direct connection and anode manifold are arranged coaxially. Combined with the stacked busbar structure, the energy storage and switching units are integrated to reduce the space area of the discharge circuit. The connection inductance is reduced by threaded connection, and the electrical isolation is enhanced by insulating base and annular flange to form a compact integrated discharge module.
The inductance and resistance of the discharge circuit are reduced, the energy transfer efficiency is improved, the voltage spikes of the switching devices are suppressed, the component life is extended, the mechanical stability and anti-interference ability of the system are enhanced, and high-quality pulse output is ensured.
Smart Images
Figure CN224935557U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of special power supply technology, and in particular to a high-voltage pulse power supply discharge module structure. Background Technology
[0002] A pulsed power supply is a special type of power supply that can release high-power electrical energy in a very short time. Its output waveform, especially the steepness of the pulse leading edge (i.e., the rise rate), is one of the key indicators for measuring its performance and directly affects its application effect in high-end industrial and scientific research fields such as laser excitation, material processing, and particle beam sources.
[0003] The core factor limiting the output performance of pulse power supplies, especially hindering the rapid establishment of the pulse leading edge, lies in the stray parameters present in the system circuit, particularly stray inductance. Under high-voltage, high-current pulse operation, even stray inductance in the circuit at the nanohenry level will cause voltage spikes and waveform oscillations due to induced electromotive force, and delay the current settling time, resulting in a slower pulse leading edge and a drop at the top. In severe cases, it may even damage the power switching devices.
[0004] In traditional pulse power supply design, the core components, including pulse capacitors as energy storage elements, power switches as control elements, and loads, are typically arranged discretely and electrically connected via copper busbars, wires, or high-voltage cables. Due to the large physical distances between these components, the connecting conductors are inevitably long. Since the self-inductance of a conductor is proportional to its length, the stray inductance of long wires becomes the primary source of the system's total stray inductance, severely degrading the pulse's fast response characteristics. Furthermore, discrete components are usually connected via external cables. These connection points (such as bolts and crimp terminals) introduce additional contact resistance and distributed inductance, creating new points of stray parameter generation and further increasing loop uncertainty. Moreover, traditional busbar arrangements are often simple parallel or discrete routing, with a large distance between the anode and cathode busbars, resulting in a correspondingly large loop area. According to electromagnetic theory, loop area is positively correlated with loop inductance; this large-area wiring method undoubtedly increases the distributed inductance of the line.
[0005] In summary, existing pulse power supply structures, limited by their discrete, long-distance layout and inefficient bus design, exhibit significant stray inductance in their system loops, making them unsuitable for modern high-power applications with stringent requirements for pulse leading-edge speed, delay, and overall waveform quality. Therefore, further optimization and improvement of current pulse power supply structures are necessary to address these technical challenges. Utility Model Content
[0006] The purpose of this utility model is to provide a high-voltage pulse power supply discharge module structure to solve the problem that the existing pulse power supply structure, due to its discrete, long-distance layout and unreasonable bus design, has a large stray inductance in its system circuit, making it difficult to meet the requirements of modern high-power application scenarios with stringent requirements for pulse leading edge, delay and overall waveform quality.
[0007] This utility model is achieved through the following technical solution:
[0008] A high-voltage pulse power supply discharge module structure includes a pulse capacitor, an insulating base, an anode busbar, an anode busbar, a cathode busbar, and a discharge power switch;
[0009] The pulse capacitor has an anode head and a cathode body; the discharge power switch has an anode connector connected to the anode head; the anode head is connected to the anode connector to form a common anode structure; the cathode body is fixedly connected to the cathode busbar.
[0010] The insulating base is disposed between the cathode busbar and the anode busbar for electrical isolation; the anode manifold is coaxially disposed on the outer periphery of the discharge power switch and connected to the anode busbar to form a discharge circuit.
[0011] Alternatively, the capacitor anode head is provided with an external thread, the anode connector is provided with an internal thread, and the capacitor anode head is threadedly connected to the anode connector.
[0012] Alternatively, the side plate of the insulating base has a basic thickness to isolate the anode busbar and the cathode busbar and reduce the loop area between them; the anode busbar, the cathode busbar and the insulating base together constitute a stacked busbar structure.
[0013] Alternatively, the cathode busbar is mounted on the end plate of the insulating base, and the end plate is provided with a strip groove.
[0014] Alternatively, the insulating base may be provided with an annular flange fitted around the outer periphery of the discharge power switch to isolate the capacitor anode from the external conductor.
[0015] Alternatively, the end face of the annular flange may be provided with an annular groove to increase the creepage distance.
[0016] Alternatively, the anode manifold includes multiple anode manifolds, which are evenly spaced along the circumferential direction and form a cage-like structure.
[0017] The number of anode manifolds is eight or more.
[0018] Alternatively, the anode collector may be arranged in a cylindrical structure on the outer periphery of the discharge power switch.
[0019] Alternatively, the anode busbar is provided with mounting holes adapted to fastening screws; the insulating base is provided with an insulating platform and a fixing cap, the insulating fixing cap being fitted around the outer periphery of the insulating platform; the fastening screw passes through the fixing cap and the insulating platform and engages with the mounting holes of the anode busbar.
[0020] The advantages of this utility model compared to the prior art are as follows:
[0021] Through the above technical solution, by coaxially arranging the common anode direct connection and the anode busbar, the dispersed energy storage and switching units in traditional designs are integrated into a compact whole. The space area of the current loop is minimized by utilizing a stacked busbar (a combination of anode busbar, insulating base, and cathode busbar), thereby reducing the parasitic inductance of the entire discharge loop. This shortens the current settling time, making the pulse leading edge extremely steep, thus reducing pulse delay. The loop inductance and resistance are effectively reduced, correspondingly reducing energy loss and waveform distortion during pulse transmission, improving energy transmission efficiency. Simultaneously, the low-inductance loop helps suppress voltage spikes generated by the switching devices during turn-off, reducing electrical stress on the switching devices, extending the service life of each component, and ensuring the reliability of the entire structure. This discharge module eliminates the lengthy cable connections between traditional discrete components, achieving high integration and modularity. This reduces size and avoids additional inductance and instability introduced by external connection points and long wires, making the system structure more robust, with stronger vibration and interference resistance, improving the overall mechanical stability and long-term operational reliability. Attached Figure Description
[0022] To more clearly illustrate the technical solutions of the exemplary embodiments of this utility model, the drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this utility model and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:
[0023] Figure 1 A three-dimensional structural schematic diagram of the high-voltage pulse power supply discharge module structure provided by this utility model in one embodiment;
[0024] Figure 2 A cross-sectional view of the high-voltage pulse power supply discharge module structure provided by this utility model from one perspective.
[0025] Figure 3A cross-sectional view of the high-voltage pulse power supply discharge module structure provided by this utility model from another perspective.
[0026] Figure 4 A cross-sectional view of the high-voltage pulse power supply discharge module structure provided by this utility model from another perspective.
[0027] Figure 5 A top view of the high-voltage pulse power supply discharge module structure provided by this utility model in one embodiment;
[0028] Figure 6 A schematic diagram of the insulating base in the high-voltage pulse power supply discharge module structure provided by this utility model;
[0029] Figure 7 A schematic diagram of the discharge system formed when the high-voltage pulse power supply discharge module structure provided by this utility model is connected in parallel.
[0030] The markings and corresponding component names in the attached diagram are as follows: 100-Discharge module, 1-Pulse capacitor, 11-Anode head of capacitor, 12-Cathode body of capacitor, 2-Insulating base, 21-End plate, 211-Strip groove, 22-Annular flange, 221-Annular groove, 23-Insulating platform, 24-Isolation platform, 25-Side plate, 3-Anode manifold, 4-Anode busbar, 5-Cathode busbar, 6-Discharge power switch, 61-Anode connector, 7-Fixing cap. Detailed Implementation
[0031] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be noted that while the description of these embodiments is intended to aid in understanding the present invention, it does not constitute a limitation thereof. The specific structural and functional details disclosed herein are only for describing exemplary embodiments of the present invention. However, the present invention may be embodied in many alternative forms and should not be construed as being limited to the embodiments described herein.
[0032] According to a first aspect of this disclosure, a high-voltage pulse power supply discharge module structure is provided. Wherein, Figures 1 to 7 Specific embodiments thereof are shown.
[0033] See Figures 1 to 7As shown, the high-voltage pulse power supply discharge module structure includes a pulse capacitor 1, an insulating base 2, an anode manifold 3, an anode busbar 4, a cathode busbar 5, and a discharge power switch 6. The pulse capacitor 1 has a capacitor anode head 11 and a capacitor cathode body 12. The discharge power switch 6 has an anode connector 61 connected to the capacitor anode head 11. The capacitor anode head 11 is connected to the anode connector 61 to form a common anode structure. The capacitor cathode body 12 is fixedly connected to the cathode busbar 5. The insulating base 2 is disposed between the cathode busbar 5 and the anode busbar 4 for electrical isolation. The anode manifold 3 covers the outer periphery of the discharge power switch 6 and is connected to the anode busbar 4 to form a discharge circuit.
[0034] The working process of this high-voltage pulse power supply discharge module is mainly divided into two stages: energy storage and pulse discharge.
[0035] During the energy storage phase, the external charging power supply charges the pulse capacitor 1, and electrical energy is stored in it in the form of an electrostatic field. At this time, the discharge power switch 6 is in the off state, the circuit between the entire module and the load is open, and it is in a state of waiting to be triggered.
[0036] During the pulse discharge phase, when the external control system sends a trigger signal to the discharge power switch 6, the switch instantly turns on. The electrical energy previously stored in the pulse capacitor 1 is rapidly released through an optimized low-inductance circuit. The discharge current path is as follows: the current flows out from the anode head 11 of the pulse capacitor 1, directly into the switch through the common anode structure formed by it and the anode connection head 61 of the discharge power switch 6. After passing through the switch, the current flows out from its casing or output terminal and enters the anode collector 3. Since the anode collector 3 covers the outer periphery of the discharge power switch 6, the current is collected and conducted to the anode busbar 4, and then flows to the external load. After the load is energized, the current returns to the cathode body 12 of the pulse capacitor 1 via the cathode busbar 5, thus forming a complete, closed, and extremely compact discharge circuit.
[0037] Through the above technical solution, by coaxially arranging the common anode direct connection and anode busbar 3, the dispersed energy storage and switching units in the traditional design are integrated into a compact whole. The space area of the current loop is minimized by utilizing a stacked busbar (a combination of anode busbar 4, insulating base 2, and cathode busbar 5), thereby reducing the parasitic inductance of the entire discharge loop, shortening the current settling time, making the pulse leading edge extremely steep, and reducing pulse delay. The loop inductance and resistance are effectively reduced, minimizing pulse energy loss and waveform distortion during transmission and improving energy transmission efficiency. Simultaneously, the low-inductance loop helps suppress voltage spikes generated by the switching devices during turn-off, reducing electrical stress on the switching devices, extending the service life of each component, and ensuring the reliability of the entire structure. This discharge module eliminates the lengthy cable connections between traditional discrete components, achieving high integration and modularity. This reduces size and avoids additional inductance and instability introduced by external connection points and long wires, making the system structure more robust, with stronger vibration and interference resistance, and improving the overall mechanical stability and long-term operational reliability.
[0038] It should be noted that directional terms such as "inner" and "outer" refer to "inner" and "outer" relative to the outline of the component. "Inner" refers to the direction towards the inside of the component, and "outer" refers to the direction away from it. Furthermore, terms such as "first" and "second" are used to distinguish one element from another and do not indicate sequence or importance. Moreover, in the following descriptions with accompanying drawings, the same reference numerals in different drawings represent the same element. The phrase "and / or" in the text refers to A and / or B, indicating that there are three possible scenarios: only A, only B, and both A and B. The phrase " / and" in the text refers to A and B, indicating that there are two possible scenarios: only A and both A and B.
[0039] In one embodiment provided in this disclosure, the capacitor anode head 11 is provided with an external thread, and the anode connector 61 is provided with an internal thread. The capacitor anode head 11 is threadedly connected to the anode connector 61. In this way, the intermediate connecting components such as cables, copper busbars and corresponding terminals required in traditional designs can be eliminated, stray inductance introduced by the inductance of the conductor itself and contact inductance can be avoided, and the physical distance and electrical path between the energy storage element and the switching element can be shortened, making its response more agile and rapid.
[0040] Based on the threaded connection between the two, during the tightening torque process, the threaded engagement can provide a large contact pressure, so that a large area of metal-metal contact is formed between the contact surfaces of the capacitor anode head 11 and the anode connector 61. This reduces contact resistance, reduces ohmic loss and heat generation during current transmission, improves energy utilization efficiency, and avoids potential failures caused by overheating of the contact point, ensuring the safety and durability of the discharge module under high current pulse discharge conditions.
[0041] In one possible embodiment, the side plate 25 of the insulating base 2 has a basic thickness to isolate the anode busbar 4 and the cathode busbar 5 and reduce the loop area between them; the anode busbar 4, the cathode busbar 5, and the insulating base 2 together constitute a stacked busbar structure. The side plate 25 of the insulating base 2 forces a fixed parallel spacing between the anode busbar 4 and the cathode busbar 5, reducing the current loop area formed by them. This sandwich-like stacked structure compresses the spatial volume of the main discharge circuit and reduces the distributed inductance of the busbar section. Simultaneously, the entire process, from energy storage and switching to the output global loop inductance, can be effectively coordinated, resulting in a steeper pulse leading edge, a flatter top, and higher energy transfer efficiency.
[0042] It should be noted that the insulating base 2 is not only an electrical isolation component, but also a structural support and positioning foundation. It can firmly integrate the anode busbar 4 and the cathode busbar 5 into a rigid structure, thereby enhancing the mechanical strength and stability of the overall structure and ensuring the reliability of long-term operation.
[0043] In one possible embodiment, the cathode busbar 5 is mounted on the end plate 21 of the insulating base 2, and the end plate 21 is provided with a strip groove 211. The end plate 21 can provide a stable and insulated mounting base for the cathode busbar 5. At the same time, the strip groove 211 can increase the creepage distance, forcing possible current leakage paths to extend tortuously along the contour of the groove, increasing the voltage threshold, thereby forming a reliable insulation barrier and enhancing the adaptability of the pulse power module in harsh environments such as high humidity and dust.
[0044] In one possible embodiment, the insulating base 2 is provided with an annular flange 22 sleeved around the discharge power switch 6 to isolate the capacitor anode head 11 from external conductors. This annular flange 22 establishes a fully enclosed physical insulation barrier between the capacitor anode head 11 (one of the highest potential points in the entire circuit) and all surrounding external conductors (such as the cathode busbar 5, the module's metal casing, or other adjacent components). This prevents air breakdown or direct short circuits between the anode and surrounding components that may occur due to falling foreign objects, accidental contact, or component displacement, thus improving the module's electrical safety.
[0045] This insulating flange, positioned between the high-potential anode and the low-potential environment, has a dielectric constant much higher than that of air. This effectively homogenizes the electric field distribution in the region, weakens electric field spikes, and reduces the occurrence of partial discharge. Simultaneously, it can also, to some extent, block and absorb electromagnetic radiation interference generated when the discharge power switch 6 operates, improving the system's electromagnetic compatibility.
[0046] Furthermore, the end face of the annular flange 22 is provided with an annular groove 221, thereby increasing the creepage distance. The annular groove 221 forces the originally straight creepage path on the flat end face to be transformed into an extended path that meanders along the inner and outer walls of the annular groove 221, thus achieving a multiple increase in creepage distance without increasing the overall height of the insulating base 2 or occupying more space. Based on the setting of the annular groove 221, a fine insulating structure can be added to the area where the electric field is most concentrated, which can effectively homogenize the electric field, disperse and weaken electric field peaks, and reduce the risk of partial discharge.
[0047] In one possible embodiment, the anode manifold 3 includes multiple anode manifold bars, which are evenly spaced along the circumferential direction and form a cage-like structure; wherein the number of anode manifold 3 is 8 or more.
[0048] Multiple busbars are evenly arranged around the outer periphery of the discharge power switch 6, forming a spatial transmission structure concentric with the switch axis, approximating a cage-like coaxial cable. This structure facilitates a uniform and symmetrical distribution of current around the switch axis, effectively compressing the magnetic field and reducing the parasitic inductance and characteristic impedance of this connection section. Compared to traditional connections using a single or a few large conductors, this symmetrical distribution more effectively suppresses pulse distortion caused by eddy currents and the skin effect, ensuring that the current pulse can be transmitted to the anode busbar 4 with extremely fast leading-edge velocity and extremely low oscillation, resulting in a high-quality output waveform.
[0049] Meanwhile, during high-current pulse discharge, the busbar itself generates Joule heat. Compared with a solid cylinder, the multi-strip structure has a larger heat dissipation area, which can dissipate heat to the surrounding environment more quickly, prevent local overheating, and ensure the current carrying capacity and operational reliability of the structure.
[0050] In another possible embodiment, the anode collector 3 is arranged in a cylindrical structure around the discharge power switch 6. This cylindrical structure forms a complete and continuous coaxial outer conductor, completely enclosing the internal discharge power switch 6. This creates a theoretically ideal coaxial cable transmission mode with the central conductor (switch), ensuring uniform current distribution across the cross-section of the cylinder. Simultaneously, this cylindrical structure effectively suppresses losses caused by the skin effect and proximity effect at high frequencies, providing an ultra-high-speed channel with extremely low inductance and minimal waveform distortion for the pulse current, maximizing the steepness of the pulse leading edge and the flatness of the top.
[0051] Of course, the cylindrical conductor, as a complete Faraday cage, constitutes a highly efficient electromagnetic shielding layer, confining the high-intensity electromagnetic radiation generated by the discharge power switch 6 during rapid switching inside, while preventing external electromagnetic interference from entering. This effectively improves the electromagnetic compatibility of the entire pulse power system, reduces its interference to surrounding sensitive electronic equipment, enhances its own anti-interference capability, and ensures stable operation in complex electromagnetic environments.
[0052] In a preferred embodiment of this disclosure, the anode busbar 4 is provided with mounting holes adapted to fastening screws; the insulating base 2 is provided with an insulating platform 23 and a fixing cap 7, the insulating fixing cap 7 being sleeved on the outer periphery of the insulating platform 23; the fastening screw passes through the fixing cap 7 and the insulating platform 23 and engages with the mounting holes of the anode busbar 4.
[0053] By combining the insulating platform 23 and the fixing cap 7, a double insulation barrier can be constructed between the metal fastening screw and the anode busbar 4, and between the screw and the external environment. The fixing cap 7 is fitted around the outer periphery of the insulating platform 23 and covers the busbar mounting hole, avoiding the potential hazards caused by direct contact with the metal fasteners and preventing short circuits caused by foreign objects falling in.
[0054] The height of the insulating platform 23, combined with the coverage of the fixing cap 7, increases the surface creepage distance from the anode busbar 4 to other grounding components, thereby suppressing surface leakage or flashover that may occur in high humidity and dusty environments, and ensuring the long-term stable insulation performance of the entire module in harsh environments.
[0055] The insulating platform 23 passes through the mounting hole of the anode busbar 4, which can serve as a positioning and radial support to prevent the busbar from shifting due to electrodynamic force or vibration when energized. With the tightening force of the fastening screws and the pressing action of the fixing cap 7, the anode busbar 4, the insulating base 2 and the lower component are firmly pressed together into a whole, enhancing the mechanical integrity and stability of the laminated busbar structure.
[0056] In this disclosure, the insulating base 2 is provided with an isolation platform 24, which has a groove, and the isolation platform 24 is covered on the fixing screw of the cathode busbar 5, thereby isolating it from the anode portion.
[0057] In this disclosure, the cathode 12 of the pulse capacitor 1 is fixedly connected to the cathode busbar 5 by fasteners. This connection method, in conjunction with the common anode structure, forms a highly compact and complete low-impedance discharge circuit. The direct, large-area contact achieved by fasteners (such as screws) results in extremely low contact resistance and connection inductance between the cathode of the pulse capacitor 1 and the cathode busbar 5.
[0058] According to a second aspect of this disclosure, a discharge system for a high-voltage pulse power supply is provided.
[0059] See Figures 1 to 7 As shown, the discharge system of the high-voltage pulse power supply includes multiple high-voltage pulse power supply discharge module structures. Among them, multiple discharge modules 100 are connected in parallel through an extended anode busbar 4, an extended cathode busbar 5, and an extended insulating base 2.
[0060] By simply lengthening the anode busbar 4, cathode busbar 5, and insulating base 2, multiple high-performance discharge modules 100 can be connected in parallel in a straight line, increasing the total output current and power of the system to meet the application requirements of different power levels. All discharge modules 100 are connected to the same low-inductance multilayer busbar system, ensuring that the key parameters such as the parasitic inductance and resistance of each module are consistent. This guarantees that each module can discharge almost synchronously when triggered, effectively superimposing the pulse current of all modules onto the load. This avoids problems such as pulse broadening, oscillation, or inter-module circulating current caused by branch differences, thereby obtaining a high-quality, high-current pulse with a steep and pure overall waveform.
[0061] Specifically, the elongated anode busbar 4, cathode busbar 5, and insulating base 2 extend along the length to accommodate multiple sets of discharge modules 100, enabling multiple branches to discharge in parallel. All modules share the same busbar system, making the system structure compact and reducing space occupation.
[0062] The above specific embodiments further illustrate the purpose, technical solution and beneficial effects of this utility model. It should be understood that the above are only specific embodiments of this utility model and are not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.
[0063] Finally, it should be noted that this utility model is not limited to the above-described optional embodiments, and anyone can derive other various forms of products under the guidance of this utility model. The above specific embodiments should not be construed as limiting the scope of protection of this utility model, which should be determined by the claims, and the description can be used to interpret the claims.
Claims
1. A high-voltage pulse power supply discharge module structure, characterized in that, This includes pulse capacitors, insulating bases, anode busbars, anode busbars, cathode busbars, and discharge power switches; The pulse capacitor has an anode head and a cathode body; the discharge power switch has an anode connector connected to the anode head; the anode head is connected to the anode connector to form a common anode structure; the cathode body is fixedly connected to the cathode busbar. The insulating base is disposed between the cathode busbar and the anode busbar for electrical isolation; the anode manifold is coaxially disposed on the outer periphery of the discharge power switch and connected to the anode busbar to form a discharge circuit.
2. The high-voltage pulse power supply discharge module structure according to claim 1, characterized in that, The capacitor anode head is provided with an external thread, and the anode connector is provided with an internal thread. The capacitor anode head is threadedly connected to the anode connector.
3. The high-voltage pulse power supply discharge module structure according to claim 1, characterized in that, The side plate of the insulating base has a basic thickness to isolate the anode busbar and the cathode busbar and reduce the loop area between them; the anode busbar, the cathode busbar and the insulating base together constitute a stacked busbar structure.
4. The high-voltage pulse power supply discharge module structure according to claim 1, characterized in that, The cathode busbar is mounted on the end plate of the insulating base, and the end plate is provided with a strip groove.
5. The high-voltage pulse power supply discharge module structure according to claim 1, characterized in that, The insulating base is provided with an annular flange that is sleeved on the outer periphery of the discharge power switch to isolate the capacitor anode from the external conductor.
6. The high-voltage pulse power supply discharge module structure according to claim 5, characterized in that, The end face of the annular flange is provided with an annular groove to increase the creepage distance.
7. The high-voltage pulse power supply discharge module structure according to claim 1, characterized in that, The anode manifold includes multiple anode manifold bars, which are evenly spaced along the circumferential direction and form a cage-like structure. The number of anode manifolds is eight or more.
8. The high-voltage pulse power supply discharge module structure according to claim 1, characterized in that, The anode collector has a cylindrical structure and is located on the outer periphery of the discharge power switch.
9. The high-voltage pulse power supply discharge module structure according to claim 1, characterized in that, The anode busbar is provided with mounting holes adapted to fastening screws; the insulating base is provided with an insulating platform and a fixing cap, the insulating fixing cap being fitted around the outer periphery of the insulating platform; the fastening screw passes through the fixing cap and the insulating platform and engages with the mounting holes of the anode busbar.