Design and analysis of PCB coils for enhancing the thermal performance of domestic induction cooktop systems

다국어 초록 (Multilingual Abstract)

This thesis proposes an optimized PCB coil geometry for reliable high-power operation, by examining loss analysis and thermal performance of the PCB coils. Recently, PCB coils have gained attention due to their benefits in weight reduction and high amount of design flexibility compared to conventional Litz wire coils. Despite these advantages, PCB coils are vulnerable to thermal stress and can affect in heating issues. The geometric configuration of the PCB coil depends on its design parameters, and these parameters significantly affect the resulting temperature rise. Therefore, geometric designs of PCB coils are constructed with varying these design parameters, including trace width (W), number of layers (n), and multi-layer stacking configuration. A comprehensive analysis of power loss calculation and temperature distribution is performed on these resulting geometries. The results show that a single-layer coil structure with a reduced outer trace width and a stack configuration with a gradually increasing number of turns from the top layer to bottom is an effective design in reducing the temperature rise. Furthermore, analysis of loss and temperature profiles with variable layer counts identified a critical trade-off point. Finally, this research proposes a single, optimized PCB coil geometry that facilitates stable vessel heating operation even under high-power conditions of 3 kW.

국문 초록 (Abstract)

본 논문은 PCB 코일의 다양한 설계 변수에 따른 형상 설계 및 온도 분석 결과를 통해 대전력 조건 동작에 적합한 PCB 코일 형상을 제시한다. PCB 코일은 기존 Litz wire 코일 대비 경량화가 가능하고 형상 설계의 자유도가 높다는 장점이 있으나, 온도에 민감하여 발열 문제가 발생할 수 있다. PCB 코일은 각각의 설계 변수에 따라 코일 형상이 결정되며, 해당 설계 변수에 따라 다양한 온도 분포 변화를 보인다. 따라서 본 논문에서는 패턴 폭, 적층 수, 적층 방안 등 설계 변수 변화에 따른 코일 형상을 구성하고, 손실 계산 및 온도 분포에 대한 분석을 진행하였다. 분석 결과, 외곽 패턴 폭을 감소시키는 단층 코일 구조 및 상단 층부터 턴 수를 점진적으로 증가시키는 적층 구조가 내부 패턴 온도 저감이 가능하다는 것을 확인하였다. 또한 적층 수 변화에 따른 손실 및 온도 분석을 통해 trade-off 지점을 확인하고, 최종적으로 3 [kW] 수준의 대전력 조건에서도 용기 가열 동작이 용이한 단일 PCB 코일 형상을 제시하였다.

목차 (Table of Contents)

• Chapter 1. Introduction 1
• 1.1 Research background and necessity 1
• 1.2 Literature review 4
• 1.3 Contents of the research 5
• Chapter 2. Design method of PCB coils 6
• 2.1 Loss analysis and calculation methods of PCB coil trace 6
• 2.2 Geometric design conditions of PCB coil 13
• 2.3 Experimental methodology and conditions 14
• 2.3.1 Experimental procedure 14
• 2.3.2 Comparative analysis of the PCB coil structure 15
• Chapter 3. Analysis of PCB coil design and thermal measurement results 17
• 3.1 Analysis of temperature profile with variable W 17
• 3.2 Analysis of temperature profile with variable number of layers 23
• 3.3 Analysis of temperature profile using layer-specific turn count PCB coils 30
• 3.4 Optimization of layer count for layer-specific turn design 39
• 3.4.1 Design of 3 layer coil (2-3-3 configuration) 39
• 3.4.2 Design of 5 layer coil (1-2-2-3-3, 1-2-3-3-3) 45
• 3.5. Analysis and comparison of the experimental results 50
• Chapter 4. Conclusion 52
• References 53
• Korean Abstract 56