Evolving at a lightning speed, EV charging, with AI-powered grids, and ultra-fast semiconductors are redefining the industry. Delving into the technology, Mr Kim Chang Min from Infineon Technologies shares insights and challenges with EFY’s Akanksha Sondhi Gaur and Nidhi Agarwal.
Q. What are the primary pillars of innovation in electric vehicle (EV) charging infrastructure?
A. The advancement of EV charging relies on four key pillars: infrastructure, charging stations, EV chargers, and semiconductors. Infrastructure ensures grid stability as EV adoption rises, balancing energy supply and demand efficiently. Charging stations are evolving to support a diverse range of vehicle types, from two-wheelers to buses and construction vehicles, making adaptability a crucial requirement. EV chargers must operate continuously to meet growing demand. Power semiconductors improve system performance, making EV charging more effective and sustainable.
Q. What is Infineon’s vision for the future of EV charging?
A. Our vision is to create a sustainable, reliable, and intelligent EV charging infrastructure that supports global electrification goals. We are committed to pushing the boundaries of semiconductor technology, integrating artificial intelligence (AI)-driven solutions, and ensuring that our innovations serve both technical and commercial needs in the EV ecosystem.
Q. What is next for EV charger technology?
A. The industry is moving toward better cooling solutions and improved power density. Silicon carbide (SiC) technology will evolve, reducing energy losses. As EV adoption grows, collaboration between industry leaders, governments, and regulatory bodies will be essential for a smooth transition to an electrified future.
Q. What are your latest R&D efforts in EV charging, and what innovations can we expect?
A. We offer advanced components and complete system solutions with optimised bill of materials (BOM) and technical details. Innovations include wireless and dynamic (on-road) charging, supported by power semiconductor controllers for high-frequency switching.
Q. What are the main challenges in EV charger development today, and how is your company addressing semiconductor challenges for the EV industry?
A. Technologically, there are no major obstacles, but challenges stem from government policies, regulatory compliance, and customer acceptance. In semiconductor technology, reliability and high-voltage capability are key. As the industry transitions to megawatt charging, the existing two-level power conversion is insufficient, necessitating three-level topologies. We are advancing high-voltage SiC devices to enable scalable solutions.
Q. What are the biggest challenges in implementing and integrating bidirectional charging technology with the power grid?
A. While technically feasible, challenges arise from regulatory differences across countries. Clear and consistent policies are essential for large-scale adoption, as they determine how bidirectional chargers interact with the grid and enable technologies such as active front-end converters and dual active bridges.
Q. What are the essential power semiconductor components in EV chargers, and why are they crucial?
A. Power semiconductors act as switches for efficient power conversion and management. Key technologies include silicon (Si), SiC, and gallium nitride (GaN). While silicon is cost-effective, SiC and GaN offer higher efficiency, faster switching speeds, and better thermal performance, making them suitable for fast-charging stations.
Q. What is the role of MOSFETs in EV chargers, and how do Si MOSFETs, SiC MOSFETs, and IGBTs compare?
A. MOSFETs allow high-frequency switching and reduce power losses. Compared to insulated gate bipolar transistors (IGBTs), metal-oxide-semiconductor field-effect transistors (MOSFETs) offer higher switching frequencies with lower conduction losses. IGBTs are suitable for high-power applications but are limited by switching losses. Si MOSFETs offer better switching performance than IGBTs, but SiC MOSFETs provide higher efficiency, reduced thermal stress, and a compact size, making them ideal for power factor correction (PFC) and DC-DC conversion applications.
Q. Besides power switches, what other semiconductor components are essential in EV chargers?
A. Another key component is the microcontroller unit (MCU). For example, our industrial MCU, called ‘PIZZA’, offers excellent connectivity and processing capabilities, supporting real-time control and communication within the charging system.
Q. How do you minimise conduction and switching losses in high-efficiency EV chargers?
A. We use optimised SiC MOSFETs and GaN-based solutions. SiC advancements offer lower R_DS(on) (on-resistance) and higher operational temperatures. Our packaging innovations reduce parasitic losses, enhance thermal performance, and improve overall efficiency. Transitioning from Generation 1 to Generation 2 SiC technology provides further performance benefits.
Q. How are thermal challenges managed in high-frequency EV chargers?
A. For chargers below 30 to 50kW, forced-air cooling is typically sufficient. For higher power levels, liquid cooling is preferred. These systems use specialised agents, such as water mixed with other materials, to dissipate heat. We support customers with power device simulations and cooler designs to ensure long-term reliability.
Q. What are the latest advancements in ultra-fast DC fast chargers?
A. While 350kW chargers are considered high power today, our focus is on enhancing packaging technology to support upcoming megawatt chargers. Our solutions provide robustness and longevity, which are crucial for sustained fast charging.
Q. What innovations has your company introduced to improve efficiency and reduce power losses in high-power charging infrastructure?
A. You see, one key innovation is our second-generation SiC MOSFETs, which reduce conduction and switching losses. These advancements minimise heat generation, reduce cooling demands, and enhance system performance.
Q. How does your technology enhance fast-charging efficiency and longevity?
A. Our gate driver technology offers junction isolation, level shifting, and silicon-on-insulator (SOI)-based drivers. We recommend lead isolation for safety. Our 2EP series transformer drivers reduce printed circuit board (PCB) size and simplify design by enabling differential isolation. These innovations extend module lifetimes by up to 10 times.
Q. How does your SiC-based solution enhance power density and charging speed in 800V+ EVs?
A. Our SiC technology supports efficient power conversion for 800V and higher systems. Charging stations with outputs from 150V to 1000V benefit from faster switching, lower heat dissipation, and improved overall efficiency.
Q. Can you compare different topologies used in EV charging?
A. EV chargers are classified as on-board (3kW–22kW) or off-board (50kW–350kW). Unidirectional chargers transfer power from the grid to the vehicle using a PFC stage with a Vienna rectifier and inductor-inductor-capacitor resonant (LLC) converters. Bidirectional chargers use an active front-end PFC stage and typically a dual-active-bridge (DAB) or capacitor-inductor-inductor-capacitor resonant converter (CLLC) topology. We offer optimised devices for both.
Q. How is the market adapting to support 1250V battery voltages in megawatt charging for buses and trucks?
A. Heavy-duty EVs like buses and trucks require larger batteries. To accommodate voltages up to 1250V, charger designs must evolve. We are developing solutions for these applications and plan to launch dedicated products in Q3 or Q4 this year.
Q. Grid-tied EV chargers are gaining attention, especially in connection with renewable energy sources. How do they communicate with resources like solar panels?
A. Modern charging stations integrate with solar panels and energy storage systems (ESS). The grid, solar power, and ESS work together to optimise energy distribution, reduce grid dependency, and enhance sustainability.
Q. How does PFC relate to harmonic distortion in EV charging?
A. Harmonic distortion is not a primary concern. PFC improves the charger’s front-end efficiency, ensuring smooth power delivery and contributing to grid stability.
Q. How does galvanic isolation factor into the charging process?
A. Galvanic isolation prevents electrical contact between high-voltage and low-voltage components, ensuring safety. It is more relevant to overall EV applications than to chargers specifically.
Q. What are the key communication protocols used in EV chargers, and how do they impact design?
A. Communication protocols vary by country and are regulated nationally. Plug types and supply voltages differ across regions, so charger manufacturers collaborate with plug manufacturers to ensure compatibility.
Q. How do different charging profiles impact battery life?
A. Most chargers use constant current constant voltage (CCCV) charging, with other modes including boost and trickle charging. Fast charging stresses semiconductors and battery cells. Infineon has introduced dot XT technology, ultrasonic welding, and advanced soldering techniques. We have also switched from aluminium to copper bond wires to enhance performance.
Q. Speaking of compatibility, how do charging stations support different EV battery chemistries?
A. Charging stations are universally compatible. The battery management system (BMS) inside the vehicle handles specific charging requirements for different chemistries.
Q. How do EV chargers determine the state of charge (SoC) of a battery pack?
A. The SoC is managed by the BMS in the vehicle. While the charger supplies power, the BMS determines how and when to charge based on the battery’s condition.
Q. How do EV chargers detect and handle faults such as overvoltage, overcurrent, and overheating?
A. Fault protection relies on sensors, gate drivers, and MCUs. Current and voltage sensors monitor abnormal conditions and work with gate drivers and MCUs to respond. Our industrial-grade sensors provide precise readings, enhancing system protection.
Q. How is your company integrating AI, digital control, and predictive maintenance in EV charger solutions?
A. We are developing controllers with AI capabilities, cloud connectivity, and improved security. These enable real-time diagnostics and adaptive control for reliable EV charging.
Q. How does your microcontroller family contribute to intelligent power management and secure communication in EV chargers?
A. Our P63 MCU family is designed for power management, connectivity, and security. These microcontrollers support intelligent energy distribution and seamless cloud communication with strong cybersecurity.
Q. It sounds like semiconductor technology is at the heart of efficient and secure EV charging. Any final thoughts on future trends?
A. The EV charging market demands faster, smarter, and more secure solutions. Wide-bandgap semiconductors like SiC and GaN will enhance efficiency, while MCUs and connectivity technologies will further optimise charging infrastructure. Infineon is committed to continuous innovation in this space.
