Passive cooler design and thermal performance analysis for high current power circuits of commercial vehicles

The rapid development and widespread use of electronic devices in our era stand out as a reflection of technological advancement. High-power electronic circuits, which have become widespread across a broad spectrum from industrial sectors to consumer electronics, have become a significant driving force behind this development. These circuits perform critical functions such as energy conversion, control, and transmission, forming one of the fundamental pillars of modern technological infrastructure. One of the high-power electronic circuits, DC-DC converters, are a type of electrical energy converter that transform electrical energy from a direct current (DC) source to a different voltage level. This conversion process is typically carried out from one voltage level to a higher or lower voltage level. These converters are widely used in electronic devices, industrial equipment, solar energy systems, electric vehicles, and many other applications. For example, they can be used to convert the low-voltage power source from a battery to a suitable high-voltage level for a device or circuit. Similarly, they are also used to convert the energy generated by a solar panel to voltage levels suitable for household electrical systems or battery systems. DC-DC converters are designed to provide efficient energy conversion and are commonly used to enhance the efficiency of electrical circuits, optimize power sources, and improve the performance of electrical systems. These converters play a crucial role when it is necessary to convert electrical energy to different voltage levels, supporting the functionality and performance of modern electronic devices. However, for these electronic circuits to operate healthily, reliably, and efficiently, electrical design alone is not sufficient; thermal management is also of critical importance. The operation of electronic components within a specific temperature range is a critical factor for the performance, reliability, and lifespan of devices. Uncontrolled temperature increases can negatively affect the ability of components to perform their functions and even lead to damage. Therefore, the thermal management of electronic devices aims to prevent undesirable heating issues by keeping the temperature of components under control. Thermal management strategies use various techniques to optimize the operating temperatures of circuits and provide adequate cooling in cases of overheating. These solutions include heat sinks, fan-cooled heat sinks, thermal interface materials, and the regulation of ambient airflow. The use of these techniques ensures that electronic devices remain within specific temperature limits, guaranteeing long-term and reliable operation. In conclusion, the adoption of appropriate thermal management strategies is vital for the reliable and efficient functioning of high-power electronic circuits, ensuring the sustainability of technological advancement. Therefore, focusing on thermal management strategies during the design and production stages of electronic devices is essential for the successful operation of today's complex and heavily used electronic systems. This thesis work encompasses the design of passive coolers and thermal performance analysis for high-current power circuits in commercial vehicles. The primary aim of the study is to optimize the thermal management of high-current carrying circuits, thereby enhancing the performance and reliability of the systems. In this context, the design of passive coolers used for cooling electronic devices and the analysis of the thermal performance of these designs are targeted. Situations where existing cooling methods are inadequate have been examined, and more effective solutions have been developed. In the first phase of the study, a comprehensive literature review was conducted on the operating conditions of electronic components, environmental factors, and power electronics. The concept and importance of thermal management were addressed, highlighting that thermal management of electronic devices uses various techniques to ensure that circuits operate within specific temperature ranges and provide adequate cooling in cases of overheating. These techniques include heat sinks, fan-cooled heat sinks, thermal interface materials, and the regulation of ambient airflow. The design and operating principles of heat sinks were focused on, and fundamental thermal principles such as the mechanism of heat, Fourier's Law, thermal conductivity coefficient, and Newton's law of cooling were explained. In this context, the fundamental equations of computational fluid dynamics (CFD), continuity equation, Navier-Stokes equations, and energy equation were examined. The design process continued by determining the electronic performance data and design criteria. For the design of the passive cooler, a heat sink design was first made, and side and top cover designs were created. For prototype production, a high-precision heat sink prototype was produced from the 6060 series aluminum alloy using the wire erosion method. A preliminary prototype was produced in the determined dimensions for the electronic board, and silicone molding was used for the side and top covers. The studies conducted within the scope of the thesis include heat sink design, prototype production, CFD analyses, and experimental tests. The heat sinks were designed and optimized to enhance thermal performance. High-precision prototypes were produced, and thermal performance tests were conducted on these prototypes. Heat transfer and flow analyses were performed using computational fluid dynamics (CFD), and the effectiveness of the designs was evaluated. Experimental tests were conducted on the produced prototypes, and the test results were analyzed. Experimental and CFD analysis results showed that high temperatures occurred in the critical areas of the DC converter, which could affect the reliability of the device. The high temperature on the heat sink surface especially emphasized the need for cooling the device. The temperature differences in the top cover area revealed that the cooling strategies needed to be reviewed. Consequently, it was determined that the thermal management system of the device needed to be optimized, and more effective cooling solutions needed to be applied. Recommendations such as expanding the heat sink surface, using more effective materials, and repositioning the internal components of the device were made. The implementation of these recommendations aims to enhance the thermal performance of the device and ensure more reliable operation. This thesis work has made significant contributions to the design of passive coolers and thermal performance analysis for high-current power circuits in commercial vehicles, providing guidance for future studies in this field. The findings obtained within the scope of the study enable the development of new design approaches for the more efficient and reliable cooling of electronic components used in commercial vehicles. Thus, the lifespan and performance of the electronic systems in commercial vehicles are extended. The results of the thesis provide important information for researchers and engineers working in the commercial vehicle industry and power electronics field. In conclusion, this thesis presents an effective passive cooler design to be used in high-current power circuits of commercial vehicles. The developed cooler enhances the thermal performance of the circuits, ensuring the reliability and efficiency of the systems. The results of the study emphasize the importance of adopting appropriate thermal management strategies during the design and production stages of electronic devices. In this way, the successful operation of today's complex and heavily used electronic systems can be ensured. The thesis forms a basis for future studies and makes significant contributions to the improvement of existing systems.