Browse Topic: High voltage systems
This document specifies dimensional, functional and visual requirements for Automotive grade coaxial cable. This material will be designated AG for general-purpose automotive applications or AG LL for low loss applications. It is the responsibility of the user of this cable to verify the suitability of the selected product (based on dimensional, mechanical, electrical and environmental requirements) for its intended application. It is the responsibility of the supplier to retain and maintain records as evidence of compliance to the requirements detailed in this standard
Heavy-duty vehicles, particularly those towing higher weights, require a continuous/secondary braking system. While conventional vehicles employ Retarder or Engine brake systems, electric vehicles utilize recuperation for continuous braking. In a state where HV Battery is at 100% of SOC, recuperated energy from vehicle operation is passed on to HPR and it converts electrical energy into waste heat energy. This study focuses on identification of routes which are critical for High Power Brake Resistors (HPRs), by analyzing the elevation data of existing charging stations, the route’s slope distribution, and the vehicle’s battery SOC. This research ultimately suggests a method to identify HPR critical vehicle operational routes which can be useful for energy efficient route planning algorithms, leading to significant cost savings for customers and contributing to environmental sustainability
ABSTRACT The latest military vehicles have been developed with on-board high voltage (600Vdc) power generation systems. The generator controller is an essential part of such a power generation system. It interfaces and converts generator 3-phase ac voltages into vehicle dc bus voltage and is the primary component responsible for vehicle bus stability. Compliance of the controller’s output dc voltage with MIL-PRF-GCS600A(ARMY) is a prerequisite for stability. This paper presents the design, and test results of a 75kW continuous operation power converter achieving a volumetric power density above 7kW/liter at an 85°C coolant temperature. Details regarding power quality and thermal management are discussed. Performance results will be provided, including assessment of the voltage regulation requirements as part of MIL-PRF-GCS600A, efficiency (97%), and temperature results
ABSTRACT The advantages of lithium-based batteries over lead acid batteries have created great interest in developing safe and cost effective drop-in replacements. To achieve the required cost effectiveness and safety of the battery, Battery Management Systems (BMS) are critical to avoid over-charging, over-discharging, and continuously and accurately determining the State of Charge (SOC), State of Health (SOH), and State of Life (SOL) of the battery. In a program funded through a U.S. Army–TARDEC SBIR, the authors developed and tested a military-grade BMS that includes: (1) a Kalman Filter-based SOC estimation algorithm with better than 5% accuracy; (2) continuous cell monitoring to avoid over-charging or over-discharging; (3) active and passive cell balancing; (4) an innovative, low cost, and high-accuracy current sensing method; and (5) vehicle-level communication capability. Our BMS uses a modular, universal architecture that supports any lithium-based chemistry, pack size, or
ABSTRACT The demand for electrical power in ground combat vehicles has been consistently increasing over the years. In the years to come, abundant onboard electrical power, along with a modernized power system to manage and distribute it, will enable leap ahead capabilities for the warfighter. A carefully architected electrical power system will also help to improve fuel efficiency while reducing maintenance and logistics burden
ABSTRACT Power and energy demands on military vehicles and other large systems have been increasing significantly and modifications to these power systems are being explored on several programs. A key decision in a new power system is determining whether to use “high voltage” or “low voltage” for distribution throughout the vehicle. This decision has far reaching consequences throughout the vehicle and needs to be made after careful consideration. This paper addresses key trade-off criteria for consideration when comparing high voltage and low voltage vehicle architectures and then addresses a few other considerations for this type of decision
A device was developed that uses composite-based nonlinear transmission lines (NLTLs) for a complete high-power microwave system, eliminating the need for multiple auxiliary systems. The interest in NLTLs has increased in the past few decades because they offer an effective solid-state alternative to conventional vacuum-based, high-power microwave generators that require large and expensive external systems such as cryogenic electromagnets and high-voltage nanosecond pulse generators
As the U.S. military embraces vehicle electrification, high-reliability components are rising to the occasion to support their advanced electrical power systems. In recent years, electronic device designers have started using wide band-gap (WBG) materials like silicon carbide (SiC) and gallium nitride (GaN) to develop the semiconductors required for military device power supplies. These materials can operate at much higher voltages, perform switching at higher frequencies, and feature better thermal characteristics. Compared to silicon, SiC-based semiconductors provide superior performance. The growing availability of these materials, in terms of access and cost, continues to encourage electrification. With the ever-present pressure of size, weight, and power (SWaP) optimization in military applications, and a desire to keep up with the pace of innovation, there's a need for capacitors that can deliver higher power efficiency, switching frequency, and temperature resistance under harsh
Pulsed field ablation (PFA) is a nonthermal method of tissue ablation technology that uses high amplitude pulsed electrical fields (PEF) to create irreversible electroporation (IRE) in tissues. Unlike traditional thermal ablation technologies, PFA does not rely on heating to damage and destroy tissue. Instead, PFA creates nanopores in cell membranes due to transient, high-voltage exposure that disrupts cell wall integrity, which leads to cell death.1
Reducing dust accumulation on any surface is key for lunar missions as dust can damage or impair the performance of everything from deployable systems to solar cells on the Moon’s surface. Electrodynamic dust shields (EDSs) are a key method to actively clean surfaces by running high voltages (but low currents) through electrodes on the surface. The forces generated by the voltage efficiently remove built up, electrically charged dust particles. Innovators at the NASA Kennedy Space Center have developed a new transparent EDS for removing dust from space and lunar solar cells among other transparent surfaces
In the dynamic landscape of battery development, the quest for improved energy storage and efficiency has become paramount. The contemporary energy transition, coupled with growing demands for electric vehicles, renewable energy sources, and portable electronic devices, has underscored the critical role that batteries play in our modern world. To navigate this challenging terrain and harness the full potential of battery technology, a well-defined and comprehensive data strategy resp. knowledge management strategy are indispensable. Conversely, the imminent and rapid progression of artificial intelligence (AI) is poised to have a substantial impact on the forthcoming landscape of work and the methodologies organizations employ for the management of their knowledge management (KM) procedures. Conventional KM endeavors encompass a spectrum of activities such as the creation, transmission, retention, and evaluation of an enterprise’s knowledge over the entire knowledge lifecycle. However
General Motors (GM) is working towards a future world of zero crashes, zero emissions and zero congestion. It’s “Ultium” platform has revolutionized electric vehicle drive units to provide versatile yet thrilling driving experience to the customers. Three variants of traction power inverter modules (TPIMs) including a dual channel inverter configuration are designed in collaboration with LG Magna e-Powertrain (LGM). These TPIMs are integrated with other power electronics components inside Integrated power electronics (IPE) to eliminate redundant high voltage connections and increase power density. The developed power module from LGM has used state-of-the art sintering technology and double-sided cooled structure to achieve industry leading performance and reliability. All the components are engineered with high level of integration skills to utilize across TPIM variants. Each component in the design is rigorously analyzed and tested from component to system levels to ensure high
Focused on the permanent magnet synchronous motor (PMSM) used in electric, this paper proposes an online insulation testing method based on voltage injection under high-temperature and high-humidity conditions. The effect of constant humidity and temperature on the insulation performance has been also studied. Firstly, the high-voltage insulation structure and principle of PMSM are analyzed, while an electrical insulation testing method considered constant humidity and temperature is proposed. Finally, a temperature and humidity experimental cycling test is carried out on a certain prototype PMSM, taking heat conduction and radiation models, water vapor, and partial discharge into account. The results show that the electrical insulation performance of the motor under constant humidity and temperature operation environment exhibits a decreasing trend. This study can provide theoretical and practical references for the reliable durability design of PMSM
This paper aims at analysing the effect of regeneration braking on the amount of energy harnessed during vehicle braking, coasting and its effect on the drive train components like gear, crown wheel pinion, spider gear & bearing etc. Regenerative braking systems (RBS) is an effective method of recovering the kinetic energy of the vehicle during braking condition and using this to recharge the batteries. In Battery Electric Vehicles (BEV), this harnessed energy is used for controlled charging of the high voltage batteries which will help in increasing the vehicle range eventually. Depending on the type of the powertrain architecture, components between motor output to the wheels will vary, i.e., in an e-axle, motor is coupled with a gear box which will be connected with differential and the wheels. Whereas in case of a central drive architecture, motor is coupled with gearbox which is connected with a propeller shaft and then the differential and to the wheels. All the components
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