Laminated Busbars in Emerging Technologies and EVs

Busbars have earned a short name ‘backbone’ in different energy applications, functioning as crucial interfaces between power modules and their electronic environments. Notably, busbars are now finding application in electric vehicle batteries, further highlighting their versatile role in different power systems.

In electric vehicles, as electricity is introduced by the batteries, busbars play an important role in distributing current flows among the different elements within the vehicle’s systems and subsystems. The major aim is to accomplish effective power conduction throughout the entire electric vehicle, a task at which busbars excel. Certainly, busbars extend beyond their electrical operations; the structural design of busbars within a vehicle is equally important. This becomes especially evident in the existence of form constraints and for efficient thermal management, where busbars play an important role in facilitating heat indulgence.

In this article, our major aim centers specifically on laminated busbars. We’ll delve into what they are, discover the market size and the benefits derived from their usage.

Laminated Busbars

Laminated busbars, also denoted as multi-layer busbars, composite copper busbars, and laminated connectors, represent a multi-layered composite structure serving as the backbone of power distribution systems. In contrast to traditional, intricate wiring busbars, laminated busbars offer a modern, easily designed, rapidly installed, and well-organized power distribution system. Laminated busbars serve as high-power modular connection structural components, featuring repeatable electrical performance, low impedance, anti-interference applications, space effectiveness, efficient reliability, and a straightforward and rapid assembly procedure. The three-dimensional structure of laminated busbars allows effective current distribution within electronic modules.

Laminated busbars find extensive applications in different segments, including wind, rail transit, and solar inverters, large UPS systems, industrial inverters, and other components demanding effective power distribution. In addition, laminated busbars are engineered components comprising layers of fabricated copper separated by thin dielectric materials, laminated into unified structures. Their primary application is for the connection between insulated gate bipolar transistors and the support capacitor in electronic systems.

Market Size

According to GMI Research, the laminated busbar market growth and size reached USD 918 million in 2021 and is predicted to hold a single value CAGR of 6.4% in the forecast period and is estimated to reach USD 1,508 million in 2029 due to a significant increase in demand for preventive and safe electrical distribution systems, developing comprehensive cost of systems, and growing focus on sustainable power.

Method of using Laminated Busbars

In electric vehicles, the laminated busbars play an important role by serving as conductors that transmit electrical energy to power-producing components within the EV electrical system. They facilitate the transfer of the electrical energy generated by the EV batteries to the vehicle’s inverter. The inverter then converts this energy into AC electricity, which powers the electric drive motor, and other subsystems in the electric vehicle.

The laminated busbar design allows high power density in power distribution. This is accomplished by directly increasing the active components for high-power conversion, like IGBT semiconductors, along with passive circuit elements such as capacitors, and EMI noise reduction filters, onto the busbar. The design optimizes the integration of these components, developing the complete effectiveness of power distribution within the system. Additionally, these components aid in conserving the volume of the circuit, optimizing the comprehensive effectiveness and compactness of the electrical system.

The laminated busbars serve a dual determination by being employed for thermal management in electric vehicles. Although, AC drive motors in EVs introduce relatively little heat, the greatest heat generation occurs along resistive junctions where the current flows in the EV’s power distribution system. Laminated busbars play an important role in efficiently managing this heat, aiding the comprehensive thermal effectiveness of the EV.

Moreover, the usage of copper or aluminum, known for their excellent thermal conductivity, enables busbars to function as a component of an EV’s thermal path. In this role, heat is effectively diverted from the heat source to a heat sink or coolant reservoir, contributing to effective thermal management within the EV system.

Advantages of Laminated Busbars

• Developed Reliability: Traditional busbars often present, difficulties due to their complex assembly procedure involving different interconnected parts and cables. Besides the time-consuming nature of the assembly, these components and cables are exposed to detrimental factors in their functioning environments, including heat and vibration. Moreover, unlike traditional busbars that pose an elevated risk of installation errors and potential vibration failures at assembly points, laminated busbars offer a distinct benefit. Laminated busbars are pre-assembled with all internal components fused into a sturdy and compact frame, significantly decreasing the risk of wiring errors and vibration failures. This design develops reliability and simplifies the installation procedure.
• Low Inductance: Laminated busbars offer the additional benefit of low inductance. Inductance, in simple terms, is the generation of an electromagnetic field when electrical power flows through a conductive material. In an electric vehicle, stray inductance can lead to interference in the electronics of the car, potential system failures, and overheating. The low inductance characteristics of laminated busbars assist impede these challenges, contributing to the complete reliability and performance of the electric vehicle’s electrical system.The construction of laminated busbars, with layered charged conductors and insulating dielectric material between each layer, leads to the cancellation of electromagnetic fields and inductance that may develop. This configuration translates to a more effective conduction system. It is not surprising that laminated busbars are considered the optimal choice for highly sensitive and critical EV power systems and subsystems, provided their ability to develop effectiveness and decrease potential electromagnetic interference.

• Developed Capacitance: In addition to low inductance, laminated busbars offer the benefit of developed capacitance. The conductive materials used contribute to developing the busbar’s capacitance, thereby increasing its ability to store electrical energy in the electric vehicle battery. This dual benefit further underscores the effectiveness and versatility of laminated busbars in EV applications.