Yuhang Yang

Bio: Yuhang Yang is an academic researcher from McMaster University. The author has contributed to research in topics: Power module & Packaging engineering. The author has an hindex of 2, co-authored 5 publications receiving 16 citations. Previous affiliations of Yuhang Yang include McMaster-Carr.

Automotive Power Module Packaging: Current Status and Future Trends

Abstract: Semiconductor power modules are core components of power electronics in electrified vehicles. Packaging technology often has a critical impact on module performance and reliability. This paper presents a comprehensive review of the automotive power module packaging technologies. The first part of this paper discusses the driving factors of packaging technology development. In the second section, the design considerations and a primary design process of module packaging are summarized. Besides, major packaging components, such as semiconductor dies, substrates, and die bonding, are introduced based on the conventional packaging structure. Next, technical details and innovative features of state-of-the-art automotive power modules from major suppliers and original equipment manufacturers are reviewed. Most of these modules have been applied in commercial vehicles. In the fourth part, the system integration concept, printed circuit board embedded packaging, three-dimensional packaging, press pack packaging, and advanced materials are categorized as promising trends for automotive applications. The advantages and drawbacks of these trends are discussed, and it is concluded that a preferable overall performance could be achieved by combining multiple technologies.

Overview of Current Thermal Management of Automotive Power Electronics for Traction Purposes and Future Directions

Abstract: The design of the thermal management solution has a significant impact on the reliability and power density of power electronics. As the electric vehicle industry moves towards increasing the efficiency and output power, the cooling system must effectively remove the excess heat dissipated in power electronics. The main heat-generating components are the semiconductor switches, but other components, such as bus bars and power capacitors also dissipate heat and require cooling. Currently, indirect, direct, and double-sided cooling methods are the most common in electric vehicles and account for 14-33% of the total volume of traction inverters. However, power electronic packaging sizes are expected to decrease, while the heat dissipation continues to increase, hence advanced cooling technologies are being investigated. This paper aims to review the thermal management strategies for major power electronics components in electric vehicles as well as their failure modes since high temperatures can be detrimental to the performance of power electronics. Cooling designs that are currently implemented in electric vehicles and future cooling trends for the next generation of power electronics are reviewed as well.

A Fast and Accurate Thermal-Electrical Coupled Model For SiC Traction Inverter

Abstract: This paper proposes a thermal-electrical coupled model for silicon carbide traction inverter design. An electrical inverter model is coupled with a Cauer thermal network in PLECS/Simulink environment. The thermal network parameters are calculated using a simplified heat transfer method which can capture the heat transfer in the solid layers and the actual coolant flow. The design target is a silicon carbide inverter with a 100 kVA peak power. Computational fluid dynamics simulations and finite element analysis are conducted to validate the model. The comparative studies demonstrate that this model has a satisfactory accuracy across a wide range of operation conditions. Finally, this model is applied in characterizing the performance of the prototype inverter. After optimization, this SiC inverter shows an overall efficiency high than 99%.

Temperature Dependent State of Charge Estimation of Lithium-ion Batteries Using Long Short-Term Memory Network and Kalman Filter

Abstract: In this paper, a new state of charge (SOC) estimation method is proposed combining Long Short-Term Memory Network (LSTMN) battery model and Kalman filter (KF) considering temperature dependency. The technique has been compared to the equivalent circuit model (ECM) and the combined model (CM) using dynamic stress test data. A KF is applied to each model to realize the dynamic estimation of battery states. Based on the collected data from the federal urban driving schedule, terminal voltage approximation and SOC estimation are carried out, and the results are compared among the models. This paper includes the following contributions: (1). A LSTMN battery model that shows stronger robustness against temperature is implemented. (2). A LSTMN-KF method is proposed for SOC estimation at different temperatures and is compared with ECM-KF method and CM-KF method. (3). The proposed method eliminates the need for SOC-OCV lookup table and does not rely on the chemical characteristics of batteries.

PCB Embedded Chip-on-Chip Packaging of A 48 kW SiC MOSFET DC-AC Module with Double-Side Cooling Design

Abstract: Packaging technology is a major challenge to tapping the performance potential of wide bandgap devices. This paper proposes a packaging design based on the printed circuit board embedded technology, chip-on-chip concept, and pressure-based contact. A silicon carbide DC-AC power module with 800V maximum voltage and 48kW continuous power is designed, which has an ultra-tiny volume dimensioned with 90 mm length, 40 mm width, and 3 mm thickness. By vertically stacking the two dies of one phase leg, the conduction path is shortened which leads to a low stray inductance. In this design, ceramic sheets are used to replace the conventional thermal interface material. Proper contacts between the module, the ceramic sheets, and the cooling system are achieved by applying clamping force. The electrical performance and thermalmechanical performance of the proposed design are evaluated by finite element analysis, including temperature distribution, thermal stress distribution, and the conduction loop stray inductance.

Hardware-Assisted Detection of Firmware Attacks in Inverter-Based Cyberphysical Microgrids

Abstract: The electric grid modernization effort relies on the extensive deployment of microgrid (MG) systems. MGs integrate renewable resources and energy storage systems, allowing to generate economic and zero-carbon footprint electricity, deliver sustainable energy to communities using local energy resources, and enhance grid resilience. MGs as cyberphysical systems include interconnected devices that measure, control, and actuate energy resources and loads. For optimal operation, cyberphysical MGs regulate the onsite energy generation through support functions enabled by smart inverters. Smart inverters, being consumer electronic firmware-based devices, are susceptible to increasing security threats. If inverters are maliciously controlled, they can significantly disrupt MG operation and electricity delivery as well as impact the grid stability. In this paper, we demonstrate the impact of denial-of-service (DoS) as well as controller and setpoint modification attacks on a simulated MG system. Furthermore, we employ custom-built hardware performance counters (HPCs) as design-for-security (DfS) primitives to detect malicious firmware modifications on MG inverters. The proposed HPCs measure periodically the order of various instruction types within the MG inverter's firmware code. Our experiments illustrate that the firmware modifications are successfully identified by our custom-built HPCs utilizing various machine learning-based classifiers.

Overview of Current Thermal Management of Automotive Power Electronics for Traction Purposes and Future Directions

Abstract: The design of the thermal management solution has a significant impact on the reliability and power density of power electronics. As the electric vehicle industry moves towards increasing the efficiency and output power, the cooling system must effectively remove the excess heat dissipated in power electronics. The main heat-generating components are the semiconductor switches, but other components, such as bus bars and power capacitors also dissipate heat and require cooling. Currently, indirect, direct, and double-sided cooling methods are the most common in electric vehicles and account for 14-33% of the total volume of traction inverters. However, power electronic packaging sizes are expected to decrease, while the heat dissipation continues to increase, hence advanced cooling technologies are being investigated. This paper aims to review the thermal management strategies for major power electronics components in electric vehicles as well as their failure modes since high temperatures can be detrimental to the performance of power electronics. Cooling designs that are currently implemented in electric vehicles and future cooling trends for the next generation of power electronics are reviewed as well.

Design and Analysis of a PCB-Embedded 1.2 kV SiC Half-Bridge Module

Abstract: This work presents a PCB-embedded silicon carbide (SiC) MOSFET half-bridge module with low loop inductances, double-sided cooling, and integrated gate driver. 1.2 kV SiC MOSFET die are embedded in FR4 using a process developed by AT&S and are electrically connected and cooled through carefully placed copper-filled microvias. The electro-thermal codesign described here limited the power-loop inductance to 2.3 nH and the maximum junction temperature to less than $175 ^{\circ}\mathrm{C}$. Furthermore, integration of the gate drive circuitry within the module limited the gate-loop inductances to 2.2 nH and allowed for a high power density. The measured junction-to-case thermal resistance with double-sided cooling is 0.12 K/W, which is 57 % lower than that of a TO-247 package. A peak efficiency of 98.2 % was achieved when the PCB-embedded half-bridge modules were tested in a 22 kW three-phase ac-dc converter.