POWER

DC Charging Station

ST’s challenge for power and control

Luigi Galioto

Technical Marketing Manager, STMicroelectronics

INTRODUCTION

The global Electric Vehicle Charging Station Market size is projected to reach 30,758 thousand units by 2027, from an estimated 2,115 thousand units in 2020, at a CAGR of 46.6%. The base year for the report is 2019, and the forecast period is from 2020 to 2027. (source Markets and Markets., February 2021).

Geographically, rapidly growing sales of Electric Vehicles in the Asia Pacific region, especially in China, has propelled the growth of the global market for electric vehicle charging stations. Europe is expected to be the second-largest market during the forecast period.

Considering the various charging level types, the Level 3 charging type (i.e DC fast charging) is expected to grow fastest during the forecast period. Level 3 charging has been growing at the quickest rate due to the convenience of fast charging EVs within 30 minutes. STMicroelectronics’ products support this market/ application. We’ll take a look at the main system architectures and the main suitable ST products in the following section.

ARCHITECTURES AND ST’S PRODUCTS

The power range for DC fast chargers covers 30-150kW and implements a modular approach (fig.1) based on 15-30 kW subunits, which are then stacked up to create the higher power DC charging system. This approach provides a flexible, fast, safe, and affordable solution.

DC Charging Station

ST’s challenge for power and control

Fig.1 – Charging station sub-unit stackable solution

ST’s products cover the main power and control unit/driving stages included in each sub-unit (fig.2).

Fig.2 – Sub-unit block diagram

Concerning the power stage (PFC + DC-DC sections), design efficiency is the key, and for a sub-unit of 15-30kW power range, ST offers suited, efficient and smart products for PFC, DC-DC and Control unit/driving stages, as reported in following sections.

PFC stage

The power factor correction (PFC) stage, for a 3-phase input, can be implemented through several configurations, and often Vienna rectifier topologies are used (fig.3, type 1 or type2).

Fig.3 – PFC Vienna rectifier topologies

Based on design and/or customer needs, ST offers a wide variety of switches (fig.3, device T):

• SiC MOSFETs Gen 2 (650V series SCT*N65G2) is based on the advanced and innovative properties of wide bandgap materials and feature very low Rdson per area that combined with excellent switching performance provides an efficient and compact design. In particular, the 4-pin SCTW90N65G2V-4 with its 18mΩ RDS(on), can comfortably handle 90 A of drain current at 100°C. • IGBTs HB2 series (650V family STGW*H65DFB2) ensures higher efficiency in applications working at medium to high frequencies. Combining both lower saturation voltage (1.55 V typ.) and lower total gate charge, this IGBT family ensures minimal overshoot voltages during turnoff as well as lower turn-off energy in application. In particular, the STGW40H65DFB-4 provides faster switching thanks to a Kelvin pin that separates power path and driving signal. • Power MOSFETs MDMesh™ M5 series (650V family, STW*N65M5)uses an innovative vertical process to have a higher VDSS rating and high dv/dt capability, outstanding RDSon x area, and excellent switching performance.

In the input stage, it is possible to control the inrush current with these devices: • SCR Thyristors TN*50H-12WY (fig.3, Vienna 1, device DA), an AEC-Q101 qualified rectifier, offers 1200V blocking capability with optimized power density and surge current capability. In this way it is possible to avoid the use of passive components that limits the efficiency and lifetime of the system.

• Rectifiers for input bridge, the STBR*12 1200 family (fig.3, Vienna1, device DB) with its low forward voltage drop, improves the efficiency of the input bridges in compliance with the most stringent standards. That products are ideal for use in mixed-bridge configurations along with ST’s SCR Thyristor.

As far as diodes are concerned, the topologies the new SiC Diodes 650/1200V series combines the lowest forward voltage with state-of-the-art forward surge current robustness. Designers can select a lower current rating diode without compromising the converter’s efficiency level while increasing the affordability of high performing systems. • 650V (STPSC*H65) on Vienna type 1 (fig.3, device DC) • 1200V (STPSC*H12) on Vienna type 2 (fig.3, device D)

DC-DC stage

In the DC/DC conversion stage, a full bridge resonant topology (fig.4) is often preferred due to its efficiency, galvanic isolation, and fewer devices.

Fig.4 – FB-LLC resonant topology

Considering a 3-phase PFC converter with Vout= 750-900V, and a HV battery of 400V-800V, for FB-LLC resonant converter ST proposes: • SiC MOSFETs Gen 2 1200V series SCT*N120G2 (fig.4, device T) • SiC Diodes 1200V STPSC*H12 (fig.4, device D)

Control unit and driving stage

Depending on the needs of the design, ST offers both MCUs and digital controllers: • The 32-bit microcontrollers most suitable for power management applications are the STM32F334 (from the STM32F3 family) and the STM32G474 (from the STM32G4 family). The STM32F3 MCU series combines a 32-bit ARM® Cortex®-M4 core (with FPU and DSP instructions) running at 72 MHz with a high-resolution timer and complex waveform builder plus event handler. The STM32G4 series’ 32-bit ARM® Cortex®-M4+ core running at 170 MHz is a continuation of the STM32F3 series, maintaining the series’ leadership in analogue that grants cost reduction at the application level, a simplification of the application design, and the chance for designers to explore new segments and applications. • The heart of the STNRG388A digital controller is the SMED (State Machine Event Driven), which allows the device to pilot six independently configurable PWM clocks with a maximum resolution of 1.3 ns. Each SMED is configured via the STNRG internal microcontroller. A set of dedicated peripherals complete the STNRG device: 4 analog comparators, 10-bit ADC with configurable op amps and 8-channel sequencer. and a 96 MHz PLL for high output signal resolution.

The new STGAP2SICS is a 6kV galvanic isolated single gate driver designed to drive SiC MOSFETs. It features a 4A sink/ source current capability, short propagation delay, up to 26V supply voltage, optimized UVLO and standby function, and a SO8W package.

ST’S EVALUATION BOARDS

For just about any application type, ST offers the right system evaluation boards for testing features of ST’s products directly in the final system or sub-system. For DC Charging station, some boards and related firmware are available as well. The STDES-VIENNARECT evaluation board (fig.5-a) features a 15 kW, three-phase Vienna rectifier with mixed-signal control for the power factor correction (PFC) stage. The high switching frequency of the SCTW35N65G2V 650V SiC MOSFETs (70 kHz), the adoption of STPSC20H12 1200V SiC diodes, and the multilevel structure allow nearly 99% efficiency as well as the optimization of passive power components in terms of size and cost. The STEVAL-VIENNARECT features mixed-signal control, with the STNRG388A controller providing digital output voltage regulation. Dedicated analog circuitry provides high bandwidth continuous conduction mode (CCM) current regulation for maximum power quality in terms of total harmonic distortion (THD<5%) and power factor (PF>0.99).

(a) (b) (c)

Fig.5 – PFC solutions for DC Charging station

The STDES-PFCBIDIR evaluation board (fig.5-b) features 15 kW, three-phase, three-level Active Front End (AFE) bidirectional converter for power factor correction (PFC) stage. The power side adopts SCTW40N120G2VAG 1200V SiC MOSFETs which guarantee high efficiency (nearly 99%). The control is based on the STM32G4 series microcontroller with connectors for communication, and test-points and status indicators for testing and debugging. The driving signals for the switching devices are managed by corresponding STGAP2S gate drivers to ensure independent management of switching frequencies and dead time. The STEVAL-DPSTPFC1 3.6 kW bridgeless totem pole boost circuit (fig.5-c) achieves a digital power factor correction (PFC) with digital inrush current limiter (ICL). It helps you to design an innovative topology with the latest ST power kit devices: a silicon carbide MOSFET (SCTW35N65G2V), a thyristor SCR (TN3050H-12WY), an isolated FET driver (STGAP2S) and a 32-bit MCU (STM32F334).

Mouser & TE Launch New Content Platform

Mouser Electronics and TE Connectivity have collaborated to create a new content platform devoted to TE’s newest resources, products, and technical insights. The new site from Mouser and TE offers a comprehensive, continually updated archive of infographics, videos, and technical articles, providing valuable insights into some of the most challenging aspects of connected automobile and smart home design. The platform is launching with more than 50 pieces of content, covering technologies including antennas, sensors, Internet of Things devices, and medical solutions. Each article includes links to relevant TE products, connecting usable information from industry experts to the technologies and solutions needed to support each application. With over 69,000 TE products, Mouser offers an ever-broadening selection of the newest TE interconnect, passive, and sensor solutions, constantly adding new products. For example, Mouser stocks TE’s FAKRA automotive connector system, which is based on FAKRA RF and USCAR standards requirements and includes RF cable assemblies, terminals, and housings. The AmbiMate sensor module MS4 series boards offer a set of four core sensors — motion, light, temperature, and humidity — with optional sensors for volatile organic compounds (VOCs), sound, and CO2. Digi-Key Electronics has unveiled a consolidated list management system, myLists, to streamline customers' BOM Manager, Price and Availability (PANDA), and Favorites into one convenient solution. The tool also offers enhanced functionality and new features. Digi-Key is introducing myLists to make it easier for customers to manage their lists all in one place In addition to providing greater convenience, myLists has more than 15 new features to benefit Digi-Key customers. Among the most notable new features is an attrition calculator to plan for overages that account for parts lost or damaged during manufacturing, the ability to upload up to 1,000line items per list, options for customizing the list view, and alternatives suggested in-line for parts when available. Digi-Key customers can use myLists as a guest but will have access to the enhanced features only if they are registered users.

Digi-Key Presents myLists List Management System

Avnet, Infineon to Deliver SiC Technologies

Avnet has partnered with Infineon on the manufacturer’s leadingedge silicon carbide (SiC) based CoolSiC technology, which delivers key benefits for engineers designing advanced power systems across a wide selection of market sectors and applications. Infineon and Avnet will collaborate over the next year and beyond to accelerate the deployment of energy-efficient power devices with CoolSic technologies. Infineon’s CoolSiC technology builds upon these inherent advantages of the semiconductor material to deliver efficiency and reliability across a variety of applications such as battery charging, photovoltaic inverters, motor drives, energy storage and power supplies. The CoolSiC portfolio ranges from SiC-based diodes and discrete MOSFETs to hybrid and full SiC modules.

element14 Offers Raspberry Pi-Designed PR2040 Chip

element14 has recently started offering the 2040 chip built on Raspberry Pidesigned silicon. This new chip, which is at the core of the $4 Raspberry Pi Pico delivers a combination of high performance, low cost, and ease of use. The Raspberry Pi RP2040 microcontroller offers high performance for integer workloads, a large on-chip memory, and a wide range of I/O options, making it a flexible solution for a wide range of microcontroller applications. Professional design engineers who are already comfortable working with Raspberry Pi will easily adopt the Raspberry Pi Pico and appreciate its ease of use and affordability. element14 is the longest-standing Raspberry Pi partner and has sold more than 15 million units to date. element14 stocks the complete range of Raspberry Pi single-board computers including the recently launched Raspberry Pi Pico.

Infineon New OptiMOS Packages in TOLx Family

Infineon Technologies new OptiMOS power MOSFET packages in the TOLx family for applications that requires high current rating, ruggedness and extended lifetime.

Features:

• Offering more choices to power system designers. • Meets diverse design needs and achieve maximum performance in the smallest space. • Innovative TO-Leadless (TOLL) package • Offers very low RDS (on) and a high-current rating over 300 A • The TOLG package combines the best features of TOLL and D2PAK 7-pin packages, sharing the same 10 x 11 mm2 footprint.

Features:

• Built-In Self-Test: Advanced diagnostics at the chip level help developers meet system-level functional safety requirements with less board space • Precision Window Monitoring: ±1 percent accuracy voltage monitoring of Undervoltage/overvoltage (UV/ OV) values can be factory set at ±4 percent to ±11 percent of the target voltage

Applications:

e-scooters, e-forklifts and other light electric vehicles (LEVs), as well as power tools and battery management systems.

Availability:

Available Now

Maxim Automotive Window Voltage Monitor

Maxim releases the MAX16137 single-window voltage monitor with built-in self-test (BIST) for the designers working to achieve automotive functional safety in Advanced Driver Assistance Systems (ADAS) to reduce solution size and complexity.

Applications:

Automotive functional safety in Advanced Driver Assistance Systems (ADAS).

Availability:

Available Now

Microchip New Tool for FPGA-Based Designs

Microchip Technology has strengthened its FPGA family’s security with the DesignShield development tool that further helps prevent this information from being extracted for malicious purposes. The DesignShield tool was created to protect developers of aerospace, defense and other high-assurance systems from cybercriminals trying to acquire an FPGA’s bitstream from the fielded system.

Features:

• It deters reverse-engineering of the bitstream, which can often include CPI. • Obscures its logical equivalent using a combination of logic and routing-based encryption techniques.

ROHM has released a new website consolidating 1,000 products under the ComfySILTM brand to support functional safety in automotive systems. Improving the searchability of products and various documents contributes to greater work efficiency for electronic circuit and system designers in the automotive field. ROHM quickly responded to these needs, and successfully acquired ISO 26262 development process certification from 3rd party certification body TÜV Rheinland.

Applications:

Protect developers of aerospace, defense and other high-assurance systems from cybercriminals.

Availability:

Available Now

ROHM New Support Site for Designers

Features:

• This new special site consolidates functional safety-compliant products under the brand name ComfySILTM. • The ComfySILTM brand targets not only vehicles, but also functional safety for other markets as well.

Applications:

Automotive Systems

Availability:

Available Now

Murata Common Mode Choke Coil

Murata Manufacturing has introduced the latest automotive common mode choke coils, DLW21SH391XQ2 and DLW21PH201XQ2 used to suppress noise for high-speed interfaces that use Serializer/Deserializer (Ser/Des) on Power Over Coax (PoC). In recent years, various sensors (vehicle-mounted cameras, LiDAR, radars, etc.) are equipped vehicles to establish self-driving car technologies.

Features:

• Capable of withstanding large currents such as 300 mA and 500 mA. • Since this technology requires a higher current compared to conventional differential interfaces (typically tens of mA), the latest Murata DLW21 products are designed to handle 300mA to 500mA.

Features:

• The EV12AQ600 has shown that it can withstand a total ionizing dose (TID) of 150kRad. • The ADC had to endure multi-axis mechanical shock and vibration tests, plus electro-static discharge (ESD), extreme temperature and thermal cycling test procedures. • It now meets NASA and ESA requirements, complying with the stringent MIL-PRF-38535 (QML-Y) and ESCC 9000 standards.

Applications:

Application of PoC

Availability:

Available Now

ST Unveils MasterGaN Reference Design

STMicroelectronics launches its first reference design for MasterGaN power packages, demonstrating how the new highly integrated devices increase power density, boost energy efficiency, simplify design, and accelerate time to market.

Features:

• 250W resonant converter with a 100mm x 60mm board outline and 35mm maximum component height. • It features the MasterGaN1. • The logic inputs are compatible with signals from 3.3V to 15V. • MasterGaN1 is suitable for high-efficiency soft-switching topologies.

Applications:

Resonant converters, active clamp flyback or forward converters and bridgeless totem-pole PFC (power factor correction) in AC/DC power supplies, DC/DC converters, and DC/AC inverters up to 400W.

Availability:

Available Now

Industry’s First 4-Channel ADC by Teledyne e2v

Teledyne e2v has started supplying mixed-signal technology that is capable of delivering exceptional degrees of reliability. The company's EV12AQ600 has just been confirmed as the industry's first 4-channel analog-to-digital converter (ADC) to be qualified for space deployment.

Applications:

Mission-critical military and avionics applications, and space qualification will open up many new opportunities for their usage.

Availability:

Available Now

RECOM’s Ultra-Wide Input DC/DC Converter

RECOM has rolled out its 16:1 ultra-wide input high-isolation quarter-brick DC/DC converter, ideal for rail and harsh industrial applications.

Features:

• The input range is 14.4V to 170V (200V for 1s). • Fully regulated available outputs are 12, 24, or 54VDC with a wide +10/-20% trim range (+18/-20% for 24V output). • Efficiency is high across the operating range, and with sufficient airflow, 150W output is available from -40°C up to at least 65°C for every variant.

Applications:

Industrial

Availability:

Available Now