Browse Topic: Switches
With the rise of software-defined vehicles and the emergence of cyber threats to vehicular systems, developing teams are compelled to conduct extensive testing on both virtual and physical prototypes at an accelerated pace. This new development landscape necessitates diagnostic tools that are both precise and adaptable. However, proprietary systems dominate this field, often hindering accessibility for students and researchers due to high costs and restrictive licensing. This paper presents the design and implementation of an open-source, low-cost remote testing system tailored for automotive development and diagnostics. The proposed system utilizes Arduino and Raspberry Pi processing units, along with relay-based switching modules, to provide secure remote control of vehicle components through a web-based dashboard equipped with authentication, scheduling, and real-time synchronization capabilities. The tested prototype showcased robust scalability, secure session handling, and seamless integration with the open-source Woodpecker EV platform at the University of Detroit Mercy. The affordability and open-source nature of the framework offer a practical alternative to proprietary tools, while also enabling future adaptation to diverse automotive contexts.
Monitoring power device temperature in an electric vehicle propulsion drive converter is extremely important to achieve full power delivery within the maximum power capability envelope. Usually, on-die temperature sensors are installed on Si-IGBT power devices in electric vehicle propulsion drive converters to enable monitoring device temperature and achieve over-temperature protection. Currently, SiC MOSFET is a promising power device in power converters of electric drives because of its lower loss, higher switching speed, higher voltage capability, and higher junction temperature limit in comparison with the widely used Si-IGBT. However, SiC MOSFET is a more expensive device, installation of an on-die temperature sensor on SiC MOSFET will significantly increase its cost and complexity. So presently, there is no junction temperature sensor installed in SiC MOSFET due to which there is great difficulty protecting SiC MOSFET from over temperature. When a junction temperature estimation method is used to monitor SiC MOSFET temperature, the power loss computation of SiC MOSFET is a key factor. However, the existing loss calculation method assumes electric motors operate at high speed and power loss is computed/estimated with rms current. When the motor operates at low speed, the existing method is not practical because of a long fundamental period of phase current. The instantaneous power losses and hence the junction temperatures of the six power converter switches are not the same under such operating conditions. Hence, the junction temperature obtained with the loss computed from the rms current value does not reflect the actual device junction temperature, which may result in a failure of power device over-temperature (OT). This paper proposes a converter power device OT protection method under low motor speed to solve the above issues. The proposed method allows system cost and complexity reduction. It computes/estimates instantaneous loss and junction temperature for each individual power device of the power converter, which enables the OT detection at the motor low speed and/or imbalance phase operation. The paper presents the technical principle of the proposed instantaneous power loss and junction temperature estimation method, and OT protection for SiC MOSFET. Its model details, simulation, and experimental test results verify the new method.
Reducing the high-voltage BEV to a household level of 120-240 volts is considered in the paper as an effective means of solving the problems of electrical safety, maintenance and minor repairs of an electric vehicle in household conditions, and distributed power supply of BEV within walking distance for the driver. The analysis of the low-voltage electric drive is performed under the assumption that the battery has a nominal voltage of 200 volts. The issues of transforming a high-voltage machine (400 volts) into a low-voltage one (200 volts) by switching the stator phase sections from serial to parallel connection without changing the overall and energy characteristics are considered. It is shown that a two-motor unit with induction machines with a capacity of 50 kilowatts can provide 100 kilowatts in long-term and up to 200 kilowatts in peak modes. The paper considers the issues of implementing a low-voltage inverter and modern trends in distributed power supply for BEVs based on low- and medium-power charging units adapted to household electrical networks. The paper contains an example of a three-phase charging device with adaptive power take-off for each phase, taking into account the instantaneous load of the network by household consumers. The paper considers the issues of implementing a positive energy balance of the BEV-charger-electric grid system using mobile energy storage devices based on the secondary use of car batteries.
Microchip Technology and Hyundai Motor Group recently announced a collaboration to test 10BASE-T1S Single Pair Ethernet (SPE) technology for advanced in-vehicle networks to provide improved ADAS and connected-vehicle features. HMG told SAE Media it is working with multiple technology partners to review the overall applicability of 10BASE-T1S technology and hopes 10BASE-T1S can help optimize the deployment of gateways and switches. The technology's ethernet-based networking concepts might also contribute to simplifying network design and implementation for future zonal architectures. We also spoke with Matthias Kaestner, corporate vice president of Microchip Technology's data center, networking and automotive business units, about the partnership, via email.
Microchip's PIC64 is a new portfolio of microprocessors that the Chandler, Arizona-based company claims could enable a generational leap in embedded processing performance for aerospace and defense applications. The new MPU technology is supported by a 64-bit reduced instruction set computer (RISC-V) architecture with an embedded Time Sensitive Networking (TSN) Ethernet switch.
This paper presents the design, implementation, and evaluation of a high-efficiency Phase-Shifted Full-Bridge (PSFB) DC-DC converter utilizing Silicon Carbide (SiC) MOSFETs for low-voltage (LV) battery charging in electric vehicle (EV) applications. The converter operates with Peak Current Mode Control (PCMC), enhanced by a digitally implemented slope compensation technique to ensure control loop stability, counter subharmonic oscillations and accurate current regulation across a wide load range. The use of SiC devices enables high switching frequencies operation with reduced conduction losses, contributing to improved efficiency and power density of converter. The hardware design utilizes a planar transformer with shim inductance to enable Zero Voltage Switching (ZVS) of the primary switches, thereby reducing switching losses and mitigating transformer flux imbalance. The secondary stage employs diode rectification, while the overall PCB layout is optimized to minimize parasitics and ensure reliable high-frequency operation. A 2.2 kW prototype was developed and tested, converting 320 V to 14 V with experimental validation performed using NXP S32E278 domain controller. The proposed control scheme demonstrates fast dynamic response, stable operation under varying load conditions. Additionally, the converter’s performance under both steady-state and dynamic conditions was simulated and validated using PSIM environments. This novel work highlights the advantages of implementing digital Peak Current Mode Control (PCMC) using a domain controller, combined with SiC technology, for next-generation EV charging systems.
Electric vehicles present unique challenges in electromagnetic compatibility testing due to compact packaging, high-frequency switching systems. This paper presents a systematic debugging methodology for identifying radiated emission and radiated immunity issues in these EV platforms. A comprehensive approach is outlined, covering radiated emission measurement; Bulk Current Injection based immunity simulation, and near-field probing techniques. For RI evaluation, BCI testing in the 20 to 400 MHz range is used to simulate radiated threats on the vehicle's power and signal harnesses and handy transmitter near field injections for higher frequency simulation. For RE diagnosis, conducted emission measurements on vehicle harnesses are performed using current probes to capture high-frequency currents. Additionally, near-field electric probes are used at the component to identify dominant noise sources such as DC-DC converters, Motor control unit, and improperly grounded shielding. Case studies on various EV vehicles highlight common failure modes. This practical diagnostic workflow provides an efficient toolkit for EMC engineers to accelerate compliance readiness, reduce test iterations, and enhance vehicle-level EMC performance for electric vehicles.
The design and improvement of electric motor and inverter systems is crucial for numerous industrial applications in electrical engineering. Accurately quantifying the amount of power lost during operation is a substantial challenge, despite the flexibility and widespread usage of these systems. Although it is typically used to assess the system’s efficiency, this does not adequately explain how or why power outages occur within these systems. This paper presents a new way to study power losses without focusing on efficiency. The goal is to explore and analyze the complex reasons behind power losses in both inverters and electric motors. The goal of this methodology is to systematically analyze the effect of the switching frequency on current ripple under varying operating conditions (i.e., different combinations of current and speed) and subsequently identify the optimum switching frequency for each case. In the end, the paper creates a complete model for understanding power losses—without relying on efficiency as a measure. This work shows how using analytical methods and computer tools can give a deeper insight into how inverter and induction motor systems lose power, offering a fresh approach to analyzing and improving these systems.
Ensuring the safety and efficiency of autonomous vehicles in increasingly complex, dynamic, and structured road environments remains a key challenge. While traditional optimization-based approaches can provide safety guarantees, they often struggle to meet real-time requirements due to high computational complexity. Concurrently, although Control Barrier Functions (CBFs) can ensure instantaneous safety with minimal intervention, their inherent locality makes it difficult to consider global task objectives, potentially leading to mission failure in complex scenarios like lane-change obstacle avoidance. To address this trade-off between safety and mission completion, this paper proposes a hierarchical switching CBF safety framework. The core of this framework is to decompose complex lane-change tasks into multiple logical phases and to activate specialized, pre-designed CBF constraint sets via a top-level logic controller. Finally, we demonstrate the feasibility and safety of the proposed framework in urban driving scenarios through MATLAB simulations.
Under the background of “dual carbon”, reducing the power consumption of electric vehicles (EVs) per 100 kilometers and improving their operating energy efficiency are the only way for the development of electric vehicles. This paper uses Yao’s theorem in the energy efficiency prediction theory of multi-unit systems to give the optimal control method for the operation energy efficiency of EVs with single motor drive and multiple gears. The optimal control method for the overall operating energy efficiency of EVs with single motor drive and multiple gears is to keep the power consumption per 100 kilometers equal before and after the gear switching, or to keep the output power of the battery equal before and after the gear switching.
With the continuous development of avionics systems towards greater integration and modularization, traditional aircraft buses such as ARINC 429 and MIL-STD-1553B are increasingly facing challenges in meeting the demanding requirements of next-generation avionics systems. These traditional buses struggle to provide sufficient bandwidth efficiency, real-time performance, and scalability for modern avionics applications. In response to these limitations, AFDX (Avionics Full-Duplex Switched Ethernet), a deterministic network architecture based on the ARINC 664 standard, has emerged as a critical solution for enabling high-speed data communication in avionics systems. The AFDX architecture offers several advantages, including a dual-redundant network topology, a Virtual Link (VL) isolation mechanism, and well-defined bandwidth allocation strategies, all of which contribute to its robustness and reliability. However, with the increasing complexity of onboard networks and multi-tasking scenarios, the existing AFDX protocol still faces challenges in certain areas. Notably, there are issues related to latency jitter control under extreme network loads, efficiency in redundant link dynamic switching, and the assurance of timely and safe transmission of mixed criticality data. To address these challenges, this paper proposes an enhanced data transmission mechanism that builds upon an improved AFDX architecture. This mechanism introduces the construction of Virtual Links, creating a point-to-point network that provides deterministic Quality of Service (QoS) guarantees. Furthermore, a parallel redundant structure is incorporated to further enhance the reliability and fault tolerance of data transmission, ensuring that critical data is transmitted accurately and efficiently in complex, high-demand environments. This research aims to optimize the overall performance of AFDX systems, supporting the evolving needs of modern avionics networks.
In this Q&A, Audrey Turley, director of lab operations – biosafety at Nelson Laboratories, spoke with Medical Design Briefs about the critical importance of monitoring and managing material changes in medical devices. Even seemingly minor shifts — such as switching suppliers or altering processing steps — can introduce unknown additives or variations that impact biocompatibility and, ultimately, patient safety. Turley discusses how manufacturers can effectively document and justify changes, maintain regulatory compliance, and strengthen supplier relationships to ensure ongoing device safety. She also shares insights into trends shaping post-pandemic supply-chain strategies and the growing emphasis on proactive risk assessment and communication across the product lifecycle.
Smarter control architectures including CAN- and LIN-based multiplexing can elevate operational efficiency, customization and end-user experience. From long-haul Class 8 trucks navigating cross-country routes to articulated dump trucks operating deep in a mining pit, the need for smarter, more reliable and more efficient control systems has never been more critical. Across both on- and off-highway commercial vehicle segments, OEMs are re-evaluating how operators interact with machines - and how those systems can be made more robust, flexible and digitally connected. Suppliers have responded to this industry-wide shift with new solutions that reduce complexity, improve durability and help customers future-proof their vehicle architectures. For example, Eaton's latest advancement is the E33 Sealed Multiplexed (MUX) Rocker Switch Module (eSM) - a sealed, modular switch solution that replaces traditional electromechanical designs with a multiplexed digital interface. Combined with Eaton's OMNEX Trusted Wireless mobile control systems, these innovations provide OEMs with a unified ecosystem for both cab-based and remote vehicle control.
University of California San Diego and CEA-Leti scientists have developed a ground-breaking piezoelectric-based DC-DC converter that unifies all power switches onto a single chip to increase power density. This new power topology, which extends beyond existing topologies, blends the advantages of piezoelectric converters with capacitive-based DC-DC converters.
A design is presented for an electro-mechanical switchgear, intended for reconfiguring the windings of an electric machine whilst in operation. Specifically, the design is developed for integration onto an in-wheel automotive motor. The motor features 6 phase fractions, which can be reconfigured by the switchgear between series-star or parallel-star arrangements, thereby doubling the torque or speed range of the electric machine. The switchgear has a mass of only 1.8kg – around one tenth of the equivalent 2-speed transmission which might otherwise be employed to achieve a similar effect. As well as the extended operating envelope, the reconfigurable winding motor offers benefits in efficiency and power density. The mechanical solution presented is expected to achieve efficiency and cost advantages over equivalent semiconductor-based solutions, which are practical barriers to adoption in automotive applications. The design uses only mechanical contacts and a single actuator, thereby offering a convincing techno-economic proposition. Furthermore, it is shown that a torque interruption time of <30ms is feasible for reconfiguration events using the mechanical relay; whilst this is longer than for a semiconductor-based solution, it is likely to be imperceptible to vehicle passengers and not affect the driver experience. The project outcomes show that mechanical relay designs can in fact provide a competitive all-round solution for this functionality, making reconfigurable motors a realistic prospect for automotive applications.
Today, our mobile phones, computers, and GPS systems can give us very accurate time indications and positioning thanks to the over 400 atomic clocks worldwide. All sorts of clocks - be it mechanical, atomic or a smartwatch - are made of two parts: an oscillator and a counter. The oscillator provides a periodic variation of some known frequency over time while the counter counts the number of cycles of the oscillator. Atomic clocks count the oscillations of vibrating atoms that switch between two energy states with very precise frequency.
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