Continuous Advancements in Laminated Busbar Technology: Low-Stray-Inductance Designs Facilitate Development in Photovoltaic Energy Storage And New Energy Vehicle Power Systems

With the continuous development of photovoltaic power generation, energy storage systems, and new energy automobile industries, power electronic equipment is being upgraded towards high power density, high switching frequency,y and high integration. In this process, the performance improvement of power devices has put forward higher requirements for electrical connection systems. As an important conductive component in power conversion equipment, the laminated busbar not only undertakes the task of power transmission, but also directly affects system stray inductance, voltage spikes, temperature rise control,ol and electromagnetic compatibility performance, and has gradually become an important structural component that affects the operational stability of power electronic equipment.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Traditional busbars usually use independent copper bars to connect the positive and negative poles. Although they have the characteristics of simple structure, convenient processing, ing and strong current-carrying capacity, in high-power and high-frequency switching applications, long current loops and large conductor spacing are prone to producing high parasitic inductance. When power devices such as IGBTs and SiC MOSFETs switch rapidly, the current change rate is large, and parasitic inductance may produce transient overvoltage, which increases the electrical stress of the power devices and affects the operational reliability of the equipment in severe cases.

 

In the laminated busbar, the positive and negative electrodes, or conductive layers with different potentials, are stacked and arranged according to the design requirements, and an insulating medium is set between the conductors to form a compact planar structure for the current loop. Since the current directions in adjacent conductors are usually opposite, their magnetic fields can cancel each other out to a certain extent, thereby reducing loop stray inductance. This structural design not only helps to improve the electrical connection performance of the power module, but also provides more possibilities for internal space optimization and modular assembly of the equipment.

 

In the actual manufacturing process, the partially laminated bus bar can only perform insulation lamination on part of the conductive area according to the spatial layout and electrical connection requirements inside the device. This structure can take into account local insulation, connection convenience, and overall assembly requirements, and is suitable for power electronic equipment with complex connection locations and the need to retain specific exposed contact areas. Compared to fully laminated structures, partial laminated designs require focused control of insulation coverage, inter-layer positioning accuracy, and dimensional consistency of connection areas.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

From the perspective of the number of structural layers, a three-layer laminated busbar is usually composed of a combination of multiple layers of conductive materials and insulating media. It can be designed according to the requirements for positive and negative electrode connections, DC bus distribution,n and auxiliary circuit connections. By rationally arranging conductor levels, spacing, ng and connection locations, the current loop can be shortened, the internal electromagnetic field distribution optimized, and the installation requirements of different power modules can be met. For equipment with compact space and complex connection paths, the multi-layer structure can also reduce the wiring complexity caused by traditional cables and independent copper bars.

 

In high-power conversion equipment, the design of busbars is closely related to the layout of power devices. A laminated busbar in a high-power converter requires comprehensive design combining DC bus voltage, rated current, switching frequency, power module location, and heat dissipation conditions. Especially under high current and high-frequency switching conditions, the conductor cross-sectional area, insulation thickness, interlayer distance, and connection interface of the busbar will affect the actual operating performance. Designers need to verify stray inductance, temperature rise,e and insulation performance through electromagnetic simulation and sample testing to avoid judging whether the product meets application requirements based on theoretical structure alone.

 

With the development of new energy vehicle electric drive systems and power battery technology, laminated busbars are gradually being used for high-voltage electrical connections inside vehicles. Laminated busbars in electric cars are typically used for connections between battery systems, inverters, power control units, and other high-voltage electrical modules. Compared with traditional cable connections, the laminated structure can be customized according to the internal space of the device, reducing the space occupied by the connection path and improving current distribution by optimizing the arrangement of conductive layers.

 

The operating environment of new energy vehicles is characterized by frequent vibrations, significant temperature changes, and large fluctuations in electrical loads. Therefore, vehicle motherboards must not only have good electrical conductivity, but also need to meet mechanical strength, insulation reliability, and long-term durability requirements. During the structural design stage, full consideration should be given to the fixing method, connector location, thermal expansion space, and thermo-mechanical matching between different materials to avoid problems such as insulation layer damage, loose connections, or local overheating during long-term operation.

 

For applications with multiple power modules and complex connection paths within the equipment, Laminated Busbars for complex Busbar Installations enable the integration of different electrical nodes in a relatively compact space through a layered layout and modular structure. Such products usually require special design based on the device structure, including conductor shape, punching position, bending angle, insulation windows,s and connection ports, etc. The assembly sequence and maintenance space also need to be fully considered during the design stage to ensure that the busbars can accurately cooperate with the power modules, support structures,es and other electrical components.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

In high-voltage inverters and special power electronic equipment, the busbar insulation structure is also the focus of design. The high-voltage explosion-proof inverter busbar needs to determine the structural plan based on the explosion-proof level, working voltage, insulation distance, and operating environment of the equipment. For applications with special protection requirements, in addition to meeting the insulation requirements between conductors and conductors to ground, it is also necessary to evaluate the temperature resistance, aging resistance,e and flame retardant properties of the insulation materials, and carry out corresponding verification according to actual equipment standards.

 

As the power levels of photovoltaic inverters and energy storage converters continue to increase, three-level topologies are adopted in some power electronics applications. Laminated Busbar for Three Level Inverter needs to be reasonably laid out according to different potential nodes such as the positive pole, midpoint and negative pole of the DC bus to control the current path and parasitic parameters of each branch. Since the three-level topology involves multiple voltage nodes, the busbar structure not only affects current transmission, but also is related to the distribution of electrical stress between power devices. Therefore, the design process needs to be optimized in combination with circuit topology, switching timing,ng and module location.

 

From a material and manufacturing perspective, laminated busbars usually use high-conductivity copper or aluminum as the conductive layer, and select PET, PI, epoxy resin,sin and other insulating materials according to application requirements. Multi-Layer Composite Structure Connection Bar uses a combination of various conductive materials and insulating media to achieve functions such as electrical connection, structural support, and insulation protection. For high current applications, the conductor material needs to have appropriate conductivity and cross-sectional area; for high voltage applications, it is necessary to focus on the dielectric strength, heat resistanclevel l,evel and long-term electrical stability of the insulating medium.

 

In the field of rail transit, Subway Laminated Busbar is mainly used in traction converters, auxiliary powsuppliess up,plies and related electrical control equipment. Since rail transit equipment needs to withstand vibrtion,, shock and temperature changes for a long time, busbar products need to strike a balance between structural strength, insulation stability, and connection reliability. According to the installation space and electrical parameters of different equipment, the manufacturing process usually requires precision stamping, bending, surface treatment,reatment and lamination of conductors, and product quality is verified through dimensional inspection and insulation testing.

 

Low inductance design is an important technical direction that differentiates laminated busbars from traditional connection structures.

 

Laminated Low Inductive Bus Bar reduces loop stray inductance by shortening the current loop distance between the positive and negative poles, allowing adjacent conductors to form closer electromagnetic coupling. For IGBT and SiC power modules, lower stray inductance helps control voltage spikes during switching and reduce transient electrical stress on power devices. However, the actual design cannot simply pursue the lowest inductance, but also needs to comprehensively consider the insulatirequirements, current-carryinging capacity, temperature rise, manufacturing tolerances, and switching characteristics of the power device.

 

In power module supporting applications, customized laminated busbars for IGBTs need to be customized according to the module terminal position, DC capacitor layout, and internal installation space of the device. Its design usually involves multiple parameters such as the number of conductor layers, thickness of copper bars, insulation materials, connection hole locations, and fixed structures. For high power density equipment, the shorter the connection distance between the busbar and the power module, the more conducive to optimizing the current loop, but it is still necessary to confirm the electrical performance and thermal stability of the connection structure through actual testing.

 

The manufacturing quality of IGBT Laminated Busbar not only depends on material selection, but is also closely related to stamping accuracy, bending consistency, and the lamination process. Deviation in the punching position of conductors may cause installation stress, and poor fit of insulation materials may form air gaps or local insulation weak areas. Therefore, it is necessary to control the critical dimensions, conductor surface condition, insulation layer thickness, and interlayer position during the production process, and verify product performance through withstand voltage, insulation resistance, and related electrical tests.

 

During the equipment matching and customized procurement process, the application requirements of specific brands or models, such as laminated busbars for Mersen, should be matched based on the actual interface size, product drawings, and equipment technical specifications, focusing on confirming the installation hole position, conductor thickness, connection direction, and insulation requirements, and avoiding alternative selection based solely on product name or appearance.

 

From the perspective of conductor processing methods, laminated copper busbars have good electrical conductivity and processing adaptability, and are currently a common structural form in laminated busbars. Copper busbars can be formed into different shapes of conductive paths through precision stamping, CNC machining, bending, and surface treatment, and then laminated with insulating media. Depending on the actual application environment, surface treatments such as tin plating, nickel plating, or silver plating can also be selected to improve the oxidation resistance and contact performance of the connection interface.

 

With the development of high-frequency power electronic equipment, Laminated Bus Bar for High Frequency Inverter has put forward higher requirements for conductor layout and electromagnetic parameters. Under high-frequency switching conditions, the skin effect and proximity effect will affect the current distribution inside the conductor, thereby changing the AC resistance and local temperature rise. Therefore, the busbar design needs to be analyzed based on the operating frequency, conductor thickness, interlayer spacing, and actual current waveform, and the conductor size and structure should be reasonably determined to avoid long-term operation due to local current concentration.

 

In the power connection system of hybrid vehicles and new energy vehicles, a two-layer laminated bus bar for hybrid vehicle applications can adopt a double-layer conductor structure according to different voltage levels and connection requirements. The close arrangement of positive and negative poles or conductors of different potentials shortens the loop path and provides a compact connection solution for battery systems, inverters, and motor control modules. For automotive applications, it is also necessary to focus on verifying the vibration tolerance, the temperature resistance of the insulation material, and the mechanical stability of the connection parts.

 

In the field of photovoltaic inverters and energy storage converters, Multilayers Laminated Bus Bar used in Photovoltaic Inverter Application for Solar Power can perform multi-layer structure design according to the electrical connection requirements of DC input, power module and AC output parts. As photovoltaic systems develop towards higher power and higher conversion efficiency, the switching speed and current density of the power devices inside the inverter continue to increase, and traditional connection methods face more limitations in terms of spatial layout and parasitic parameter control. By rationally designing the laminated busbar, the internal electrical connections of the equipment can be optimized, unnecessary connection paths can be reduced, and the compact layout of the power module can be supported.

 

From the perspective of industry technology development trends, laminated busbars are evolving towards high power density, precision, and integration. On the one hand, the application of wide bandgap semiconductor devices such as SiC promotes the development of power conversion equipment towards higher switching frequencies, putting forward more stringent requirements for busbar stray inductance and insulation design; on the other hand, the integration of busbars with decoupling capacitors, sensors and modular connection structures also provides new design directions for optimizing the internal space of power electronic equipment.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

In addition, the application of three-dimensional structural design, precision laser processing, automated lamination, and digital inspection technology can help improve the manufacturing consistency of complex busbar products. For equipment with special electrical topology and installation space requirements, customized design will become an important direction in the development of laminated busbars. Manufacturing companies need to establish a complete quality control process from preliminary structural assessment and material selection to mold development, processing and assembly, and performance verification.

 

For engineering purchasers of photovoltaic inverters, energy storage converters, new energy vehicles, and industrial power equipment, the selection of laminated busbars should not only focus on copper thickness and product appearance, but also include key parameters such as rated voltage, current, operating frequency, installation space, power module model, insulation level, and temperature rise requirements. For customized projects, it is recommended to provide 2D engineering drawings, 3D models, or samples simultaneously for structural feasibility assessment and manufacturing plan confirmation.

 

By clarifying acceptance requirements such as stray inductance, insulation performance, current-carrying capacity, and dimensional tolerances in the early stage, sample verification efficiency can be improved, and batch assembly risks can be reduced. If you have customization needs for laminated copper busbars, IGBT busbars, or photovoltaic energy storage inverter busbars, you can submit product drawings and technical parameters to further communicate with the engineering team on materials, lamination processes, connection structures, and mass production plans.