Browse Topic: Voltage regulators
As the complexity of electrified powertrains and their architectures continue to grow and thrive, it becomes increasingly important and challenging for the supervisory torque controller to optimize the torque commands of the electric machines. The hybrid architecture considered in this paper consists of an internal combustion engine paired with at least one electric motor and a DC-DC switching converter that steps-up the input voltage, in this case the high voltage battery, to a higher output voltage level allowing the electric machines to operate at a greater torque range and increased torque responsiveness for efficient power delivery. This paper describes a strategy for computing and applying the losses of the converter during voltage transformation to determine the optimal engine and electric motor torque commands. The control method uses a quadratic fit of the losses at the power limits of the torque control system and on optimal motor torque commands, within the constraints of
The driving capability and charging performance of electric vehicles (EVs) are continuously improving, with high-performance EVs increasing the voltage platform from below 500V to 800V or even 900V. To accommodate existing low-voltage public charging stations, vehicles with high-voltage platforms typically incorporate boost chargers. However, these boost chargers incur additional costs, weight, and spatial requirements. Most mature solutions add a DC-DC boost converter, which results in lower charging power and higher costs. Some new methods leverage the power switching devices and motor inductance within the electric drive motor to form a boost circuit using a three-phase current in-phase control strategy for charging. This approach requires an external inductor to reduce charging current ripple. Another method avoids the use of an external inductor by employing a two-parallel-one-series topology to minimize current ripple; however, this reduces charging power and increases the risk
This SAE Recommended Practice covers the design and application of a 120 VAC single phase engine based auxiliary power unit or GENSET. This document is intended to provide design direction for the single phase nominal 120 VAC as it interfaces within the truck 12 VDC battery and electrical architecture providing power to truck sleeper cab hotel loads so that they may operate with the main propulsion engine turned off.
Solar powered UAV mainly relies on solar energy for range, it uses photovoltaic cells to convert solar radiant energy into electric energy for the use of solar powered UAV energy system. In response to the issue of solar powered UAV photovoltaic power supply energy utilization efficiency, an intelligent sliding mode based MPPT control method is proposed to maximize the output power of photovoltaic power supply. Firstly, introduce and analyze the photovoltaic cell model and its output characteristics; Secondly, the DC/DC converter and its MPPT control technology are introduced. Traditional MPPT control methods such as perturbation and observation and incremental conductance have poor adaptability to external environmental changes, the intelligent algorithm has the characteristics of fast rate of convergence and global search, etc. Therefore, on the basis of sliding mode control, this article introduces genetic algorithm for multi-objective function parameter tuning of sliding mode
This SAE Aerospace Standard (AS) establishes the characteristics and utilization of 270 V DC electric power at the utilization equipment interface and the constraints of the utilization equipment based on practical experience. These characteristics shall be applicable for both airborne and ground support power systems. This document also defines the related distribution and installation considerations. Utilization equipment designed for a specific application may not deviate from these requirements without the approval of the procuring activity.
All electrically powered autonomous vehicles possess a system that distributes power to all the vital components of the vehicle. The U.S. Army Combat Capabilities Development Command (DEVCOM) Army Research Laboratory (ARL) uses group 1 unmanned aerial systems (UASs) (weighing 20 lb) as the vehicle platform in several projects. Army Research Laboratory, Aberdeen Proving Ground, MD All electrically powered autonomous vehicles possess a system that distributes power to all the vital components of the vehicle. At the U.S. Army Combat Capabilities Development Command (DEVCOM) Army Research Laboratory (ARL), several projects are using unmanned aerial systems (UASs) as a vehicle platform. Some UAS being used are classified as group 1, meaning they weigh under 20 lb. The group 1 UASs that ARL conducts research with are very fast and agile quadrotors. Such quadrotors typically have four rotors and light payloads and can very quickly accelerate and effortlessly reach speeds over 100 kph. To do
Transportation electrification is much needed as it can help to reduce the consumption of petroleum fuels. At the same time importance of the charging system to energize electric vehicles is also growing. Currently AC level 1 charging (120V, <2KW) and AC level 2 Charging (240V, <10KW) are used to charge the electric vehicle in residential and workplaces. The off-board chargers have significance as they can charge the vehicles in less time like gas/petrol stations. These off-board charging stations are comprised of two power conversion stages. One is for the rectification process along with power factor correction to obtain DC output from the input utility grid and DC/DC stage to get the regulated DC voltage from the rectifier output. One can reduce the charging time by increasing the output charging power at the power conversion stage. Hence, the present work deals with a novel DC-DC converter topology for fast charging applications and the novelty lies in the Electric vehicle charging
This document defines the test procedures and performance limits of steady state and transient voltage characteristics for 12 V, 24 V, or 48 V electrical power generating systems used in commercial ground vehicles.
The design of complex, high-power DC-to-DC converter architectures poses some challenges to engineers developing aerospace and military-grade power systems. DC-DC converters must comply with multiple standards and stringent requirements in terms of input voltage, EMI (electromagnetic interference) environmental conditions, and thermal management. A modular approach can significantly simplify the design process, enabling engineers to design complex power conversion systems using COTS and SWaP-C optimized building blocks. Engineers can meet multiple industry standards and power requirements while optimizing their power architectures according to new industry standards such as the Sensor Open System Architecture (SOSA).
The design of complex, high-power DC-to-DC converter architectures poses some challenges to engineers developing aerospace and military-grade power systems. DC-DC converters must comply with multiple standards and stringent requirements in terms of input voltage, EMI (electromagnetic interference) environmental conditions, and thermal management.
The ability to precisely control electrical voltages on a large scale has made possible many efficient, powerful innovations, from high-speed electric trains to wind turbines to electric drive motors for everything from heavy earthmoving equipment to personal electric vehicles (EVs). But the equipment that manages this process — including power inverters, thyristors and variable-speed drives — requires high-performance power electronics cooling. As temperatures rise,the efficiency, reliability, and life spans of these devices drop, and the power electronics inside HEVs and EVs are no exception. Advancements in power electronic thermal management technologies will enable next generation automotive to fulfill increasingly demanding mission objectives. DC-DC converter and inverter systems slated for higher performances, reliable and sustainable applications. Even with very high efficiencies, the components of these systems produce kilowatts of power loss in the form of heat. The current
This SAE Standard applies to all types of heavy-duty storage batteries for use on off-road machines as described in SAE J1116. Included are definitions of industry terms, test procedures, general requirements, application recommendations, standard sizes, overall dimensions, and electrical values.
This SAE Aerospace Recommended Practice (ARP) outlines the design and performance requirements for a battery-powered electric tow tractor for the handling of baggage or cargo trailers in airline service. The use of “shall” in this document indicates a mandatory requirement. The use of “should” indicates a recommendation or that which is advised but not required.
As the climate change & CO2 emissions are becoming prime concerns over the globe, Electric Vehicles (EV) are proving to be promising eco-friendly mobility solution. In India too, the transition to electric vehicles is gaining momentum. Batteries constitute a major chunk in the cost of an EV. Battery Management Systems (BMS) are of paramount importance for safety, performance, usability & lifetime of EV. Along with fundamental function of monitoring (cell voltage, pack voltage, pack current, cell/pack temperature), BMS must perform function of controlling (charger/load connect, disconnect, pre-charge) the battery pack in case of failures. In most EVs load capacitance (traction motor controller, charger, DC-DC converter) draws high inrush current from the battery pack. This may not only damage the contactors (connect/disconnect circuits) and other load components but can also affect the lifetime of cells within battery pack. Conventionally, contactor-based cut-off & relay-based pre
This paper describes the implementation, integration, testing and performance evaluation of compact and battery-less alternator with external regulator for diesel engine for avionics application. The key responsibility of this alternator is to generate 2.8kW power with 28V regulated power supply for various loads. The alternator has been integrated and installed on the diesel engine and further tested on dynamometer and thrust cradle with propeller combination. The alternator when used in conjunction with ACU (Alternator Control Unit) that is designed to boot strap field voltage during low speed operation, has the ability to self-excite. The alternator / ACU system has the ability to generate power even in the absence of battery voltage i.e. in battery less systems or those in which the battery is not always connected to the alternator. External voltage regulator has been used which minimizes ripple up to 1.0V. The alternator rpm ranges from 3000 to 10000 for generating maximum power
Circuit designs exploiting the increased energy storage provided by supercapacitors require more careful consideration of the increased power handling than that of batteries when charging these devices. The unique composition of electrochemical double-layer capacitors (EDLC) inherently allows them to withstand large currents. Table 1 is a brief list of AVX cylindrical (SCC) and series-connected module (SCM) SuperCapacitors, displaying peak current supply and sink current capability. These maximum specifications will typically exceed current capability of charge sources and lead to failures within the power supply system.
This SAE Aerospace Recommended Practice (ARP) outlines the functional and design requirements for a b self-propelled belt conveyor for handling baggage and cargo at aircraft bulk cargo holds. Additional considerations and requirements may legally apply in other countries. As an example, for operation in Europe (E.U. and E.F.T.A.), the applicable EN standards shall be complied with.
Owing to its advantages of high energy density, quick start-up, and no emissions, the proton exchange membrane fuel cell (PEMFC) is one of the most promising power sources in transportation and has been used for automotive application for years. However, shortcomings in fuel cell key performances, such as lifetime and efficiency, characterized by state of health (SOH), restrict the large-scale commercialization for fuel cell electric vehicles (FCEV), raising demands for real-time state monitoring. Nowadays, most researchers have explored the reasons for state change from models or experiments. Nevertheless, it is in need of system-level researches on definition methods of SOH against the actual automotive application. Lacking accurate quantitative indicators, existing studies on health states are often qualitative and hence fail to consider intermediate processes. In addition, too many health indicators that describe typical physical characteristics can be used for SOH definition
This guideline is applicable to existing lead solder production products that will change to lead-free solder processes to meet the ELV Directive 2000/53/EC Annex II, exemption 8B requirements. This guideline is applicable to similar products used by multiple OEM's that have the same manufacturing processes / equipment. The intent is to streamline the supplier’s environmental testing via common qualification to reduce timing, quantities, and costs.
This SAE Recommended Practice covers the design and application of a 120 VAC single phase engine based auxiliary power unit or GENSET. This document is intended to provide design direction for the single phase nominal 120 VAC as it interfaces within the truck 12 VDC battery and electrical architecture providing power to truck sleeper cab hotel loads so that they may operate with the main propulsion engine turned off.
In order to reduce development cost and time, frontloading is an established methodology for automotive development programs. With this approach, particular development tasks are shifted to earlier program phases. One prerequisite for this approach is the application of Hardware-in-the-Loop test setups. Hardware-in-the-Loop methodologies have already successfully been applied to conventional as well as electrified powertrains considering various driving scenarios. Regarding driving performance and energy demand, electrified powertrains are highly dependent on the dc-link voltage. However, there is a particular shortage of studies focusing on the verification of variable dc-link voltage controls by Hardware-in-the-Loop setups. This article is intended to be a first step towards closing this gap. Thereto, a Hardware-in-the-Loop setup of a battery electric vehicle is developed. The electric powertrain consists of an interior permanent magnet synchronous machine and an inverter, which are
Lithium ion technology is state of the art for actual hybrid and electrical vehicles. It is well known that lithium ion performance and safety characteristics strongly depend on temperature. Thus, reliable temperature measurement and control concepts for lithium ion cells are mandatory for applications in electrical cars. Temperature sensors for all individual cells increase the battery complexity and cost of a battery management system. Normally, temperature is measured on module level in current battery packs, without observation of the individual cell temperature. Sensorless cell impedance-based temperature measurement concepts have been published and are validated in laboratory studies. Dedicated test equipment is usually applied, which is not useful for automotive series application. This work describes a practical approach to enable impedance-based sensorless internal temperature measurement for all individual cells using state-of-the art battery management system components
People and power don’t mix well, and this is particularly true when people are medical patients. Aside from the more usual environment of a medical facility, patients are also increasingly using medical devices at home. Medical equipment is therefore heavily regulated by standards-based requirements and subsequent product testing to ensure the safety of patients and healthcare professionals alike.
It is the purpose of this document to present design recommendations that will provide a basis for satisfactory and safe electrical installations in transport aircraft. This document is not intended to be a complete electrical installation design handbook. However, the requirements for safety extend so thoroughly throughout the electric systems that few areas of the installation are untouched by the document. It is recognized that individual circumstances may alter the details of any design. It is, therefore, important that this document not be considered mandatory but be used as a guide to good electrical application and installation design. Transport aircraft electric systems have rapidly increased in importance over a number of years until they are now used for many functions necessary to the successful operation of the aircraft. An ever increasing number of these functions are critical to the safety of the aircraft and its occupants. The greatly increased power available in
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