Auxiliary Power Module Research Articles

An All-in-One Magnetic Structure for Entire ZVS Range Auxiliary Power Module in Electrical Vehicles

An All-in-One Magnetic Structure for Entire ZVS Range Auxiliary Power Module in Electrical Vehicles

An Integrated Electric Vehicle Charging System of Wireless Power Transfer and Auxiliary Power Module With Shared Converter and Magnetic Coupler

An Integrated Electric Vehicle Charging System of Wireless Power Transfer and Auxiliary Power Module With Shared Converter and Magnetic Coupler

Model and Control of a Current-Fed Dual Active Bridge Based Ultrawide-Voltage-Range Auxiliary Power Module for 400 V/800 V Electric Vehicles

Model and Control of a Current-Fed Dual Active Bridge Based Ultrawide-Voltage-Range Auxiliary Power Module for 400 V/800 V Electric Vehicles

Full Integration of On-Board Charger, Auxiliary Power Module, and Wireless Charger for Electric Vehicles Using Multipurpose Magnetic Couplers

Full Integration of On-Board Charger, Auxiliary Power Module, and Wireless Charger for Electric Vehicles Using Multipurpose Magnetic Couplers

Advanced Design and Small-Signal Modeling of ACF Converter for Auxiliary Power Modules Considering Transformer Impedance

Advanced Design and Small-Signal Modeling of ACF Converter for Auxiliary Power Modules Considering Transformer Impedance

A Review of Electric Vehicle Auxiliary Power Modules: Challenges, Topologies, and Future Trends

The auxiliary power module (APM) is a vital component in electric vehicles (EVs) that enables efficient power transfer from the traction battery to low-voltage electrical loads and the 12-V battery. As the EV industry continues to evolve, APM design is facing increasingly stringent challenges, including the need for higher power ratings, higher voltage ranges, higher reliability, and higher power density, with a continued need for efficient operation. However, there is a lack of literature that comprehensively reviews recent APM topologies based on these evolving requirements. This paper fills this research gap by comprehensively reviewing current APM topologies from both academia and industry, including unidirectional and bidirectional topologies, single-stage and two-stage topologies, and multifunctional topologies. Furthermore, this paper explores several potential future trends for APM design and development.

A Low-Cost Battery-Balancing Auxiliary Power Module With Dual-Active Half Bridge Links and Coreless Transformers

Redistributive balancing brings many benefits to electric vehicles, such as increased range and more uniform cell degradation. Despite previous analyses suggesting a 17-36% extension of battery lifetime, the cost of such systems has prevented the technology from being adopted in practice. This study proposes a simplified topology for battery-balancing auxiliary power modules with reduced magnetic material to achieve cost-friendly solutions without sacrificing functionality or balancing modes. The proposed system consists of a dual-active half bridge, halving the number of switches needed compared with the conventional dual-active bridge. In addition, the transformer core material is removed and a coreless transformer is used to provide isolation and energy transfer. Both changes reduce the cost of redistributive balancing. The topological modeling differs from cored transformer circuits as the coupling of the coreless transformer is weaker. The coupling coefficient is now used in an updated model that includes transformer currents and output powers. These, along with the balancing modes, are analyzed then experimentally verified. The proposed models can guide the selection of MOSFETs and the design of the coreless transformer. An analytic projection shows up to a 22% cost reduction compared with similar topologies.

An Integrated Power Decoupling Method for Single-Phase EV Onboard Charger in V2G Application

Instead of bulky passive filters, the active power decoupling (APD) method can be adopted to suppress the 2nd-order ripple power in the DC-bus of the single-phase electric vehicle (EV) onboard charging system. However, the traditional APD methods require additional power switches and energy storage devices, which increases the cost and significantly reduces the power conversion efficiency. To tackle these problems, an integrated method of utilizing the auxiliary power module to form a series-connected APD circuit is proposed in this paper. Without additional switches and energy storage devices, the APD circuit only needs to compensate less than 10% of the rated power, while realizing soft-switching operation. In addition, the corresponding control method can further reduce the voltage stress of the switches on the high-voltage side of the converter, and increase the efficiency of the system. Finally, a 2kW single-phase charging system prototype is built to verify the feasibility and effectiveness of the proposed method.

Power Electronics Converters for Electric Vehicle Auxiliaries: State of the Art and Future Trends

Electric vehicles (EVs) are expected to take over the transportation and mobility market over traditional internal combustion engine (ICE) vehicles soon. The internal power demands of EVs are expected to increase. The reason for this is to achieve a longer driving range for the EV and to provide the required power for the low-voltage (LV) network auxiliary loads. To illustrate, there are extra added sensors, cameras, and small actuating motors, especially for future autonomous vehicles. Therefore, a new electrical/electronic (E/E) architecture is required to convert the high-voltage (HV) traction battery voltage (e.g., 320–800 V DC) to the standard LV levels with high current ratings of 5 kW and more. This HV-LV DC-DC converter is known in the literature as an auxiliary power module (APM). The standard LV rails in an EV are the 12 V/24 V rail to supply for an instant the EV’s lighting and electronic control units (ECUs), while the 48 V rail is required for propulsive loads, such as air compressors and electric power steering systems. Furthermore, in a few applications, this converter is responsible for voltage upwards to support the start of a hybrid vehicle or emergency backup power handling, which requires bidirectional capability. Therefore, in this paper, possible APM topologies for EV applications are presented. In line with this, the main standards and safety requirements of the APMs are presented. Detailed quantitative and qualitative comparisons between topologies and their associated control schemes are discussed. In addition, the placement of the APM in the EV cooling cycle has been investigated and demonstrated. Finally, the industrial trends and future research targets for the APM in automotive applications are outlined.

Auxiliary Power Module Elimination in EVs Using Dual Inverter Drivetrain

As electric vehicles compete with internal combustion engine cars, cost and weight savings remain central research objectives. The auxiliary power module, a dc/dc converter responsible for stepping down the power from the main traction battery to the auxiliary battery, has gained attention as a component where weight and cost savings can be achieved. With the auxiliary power module responsible for feeding everything from headlights to rising vehicular computational demands, these savings become evermore significant. This article introduces a system that integrates traction-to-auxiliary power conversion into the dual inverter drivetrain, leveraging typically underutilized degrees of freedom in the drive inverter to implement and control the dc/dc conversion eliminating the auxiliary power module. Due to the high level of integration, the proposed solution improves on existing literature by exclusively using the drivetrain’s active switches. Beyond capital savings and simplicity, this ensures no additional switching losses compared to regular driving operation. A mathematical model is motivated analytically and validated using computational simulations. A 1.2 kW prototype is constructed to validate the introduced concept experimentally.

Design of hybrid SiC/Si based T‐type three‐level LLC$ LLC$ resonant converter with wide‐input range and low conduction loss for automotive auxiliary power module

The auxiliary power module (APM) in the electrical vehicle converts the high voltage of battery pack to the low voltage to supply the electric power for the internal loads, including electric power steering, electric turbo, headed windshield and cooling pumps. The increasing demands on charging time and mileage have made the battery packs with even higher voltage (e.g. 800 V) a promising option. However, it brings a new challenge for the APM, and either the 1.2-kV silicon carbide (SiC) device or the three-level (TL) topology are used conventionally. This work proposes a cost-effective hybrid SiC/Si-based T-type TL L L C $ LLC$ resonant converter for the vehicular APM application with a high step-down ratio. The 1.2-kV SiC and 650-V Si devices are used as the main and auxiliary switches, respectively. It fully utilizes the voltage rating of device, and also improves the efficiency compared with conventional TL topology. To improve the gain range and electromagnetic interference performance, a variable frequency and adjustable phase-shift modulation scheme is adopted. At the same time, the steady-state time-domain model is established to elaborate the operation principles, topology features, and boundary conditions for soft-switching. Furthermore, the precise solutions for switching frequency and phase-shift angle are figured out. Finally, the effectiveness of model is verified by the simulation as well as the experiment. A 1-kW prototype for the application in the APM is demonstrated with the input voltage of 640–840 V and a constant output of 48 V/ 21 A.

Charging Electric Vehicle Batteries: Wired and Wireless Power Transfer: Exploring EV charging technologies

Due to the environmental concerns about CO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -caused global warming, policymakers are pushing electrified vehicles (EVs) to reduce these emissions. For passenger vehicles only, the electrified fleet is forecasted to reach 80 million in the U.S. and 500 million globally by 2040. Key enablers for such rapid EV adoption include the improvement of battery energy density, lifespan and safety, and drastic cost reduction of batteries and power electronics. The technology of power electronics nowadays can be found in many aspects of EVs. It alters and transforms the energy from the power source to different forms to feed the loads. For example, the on-board charger (OBC) accepts ac input and converts it to high voltage (HV) dc to charge the propulsion battery. An auxiliary power module (APM) steps down the HV battery voltage to low voltage (LV) to charge the LV battery <xref ref-type="bibr" rid="ref1" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">[1]</xref> . The HV dc bus voltage is converted to an ac form to drive the propulsion motor, forming the motor drive inverter. Putting the power electronics system and the batteries together, the typical structure of an EV is shown in <xref ref-type="fig" rid="fig1" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Figure 1</xref> . In addition, power electronics can be found in other onboard auxiliary circuits, such as LED lighting and battery management system (BMS).

Design and Implementation of Single-Input-Multi-Output DC-DC Converter Topology for Auxiliary Power Modules of Electric Vehicle

A compact DC-DC converter is required as an auxiliary power module in Electric Vehicles (EVs) to power the onboard electric motor and other auxiliaries. Most of the existing multi-port converters have limitations on duty ratio, charging currents of the inductor (iL1&#x003E;iL2 or iL1&#x003C;iL2), output voltages (V01&#x003E;V02 or V01&#x003C;V02), and the issue of cross-regulation during load variation. This paper presents a multi-port DC-DC converter with Single-Input Multiple-Output (SIMO) to circumvent all these limitations. The proposed topology generates independent outputs without affecting the other loads during the operation. It is observed that cross-regulation is effectively eliminated while controlling the loads. The control of the converter is simple without any duty ratio and inductor current charging constraints. The validity of the proposed converter has been verified by using a prototype with a 100W rating and delivers two output voltages of 24V and 14.4V at duty ratios of 50% and 30% with an input voltage of 48V. It can be extended to multiple outputs. The simulation and experimental results are analyzed to prove the effectiveness of this auxiliary power module for EV applications.

A Natural Bidirectional Isolated Single-Phase AC/DC Converter With Wide Output Voltage Range for Aging Test Application in Electric Vehicle

To ensure the safety and reliability, the aging test of on-board charger (OBC) and dc/dc auxiliary power module (dc/dc-APM) in electric vehicles are indispensable. However, a wide range of battery voltage levels and fast response to power conversion between forward and backward operations are still challenging aspects of the aging test power system. In this article, an improved ac/dc converter is proposed for the aging test application in electric vehicles. The converter consists of two identical topologies, which is made up of three cascaded converters. The first stage is a single-phase ac/dc rectifier, which realizes unity input power factor and power transmission between the ac grid and dc bus. The second stage is the LLC-dc/dc transformer (LLC-DCX) which provides electrical isolation and fixed voltage transfer ratio. Besides, the natural bidirectional power flow can be achieved by the proposed solution. The third stage is a synchronous buck converter (SBC) which guarantees the high dynamic performance and wide range voltage regulation. Experiments based on an 8-kW prototype are conducted to verify the feasibility and effectiveness of the proposed converter and the related control strategies.

Design a 400 V–12 V 6 kW Bidirectional Auxiliary Power Module for Electric or Autonomous Vehicles With Fast Precharge Dynamics and Zero DC-Bias Current

An auxiliary power module in electric vehicles is a dc/dc converter bridging the high-voltage propulsion battery with a low-voltage auxiliary system. In the coming era of connected and autonomous vehicles, the power rating of such dc/dc converters is expected to surge from 2.5 to 6 kW. In addition, there is the challenge of a wide operating voltage range, e.g., 250–450 V required by the high-voltage propulsion battery and 10–16 V at the low-voltage auxiliary battery. To meet these voltage and power challenges, this article proposes a two-stage bidirectional design, i.e., interleaved buck + dc transformer (DCX) that offers full voltage range coverage, 3.5 kW rated power, and peak power of >6 kW. Experimental results indicated >96% efficiency, owing to the zero-switching loss of DCX. Furthermore, the precharge mode that charges the input dc-bus capacitor with the low-voltage battery is accomplished using the inner phase shift control of the DCX stage. DC-bias blocking capacitors on the low-voltage side are replaced with a simple, unique dc-bias detection circuit that samples and eliminates the dc-current offset of the transformer. Simulation and test results confirm that the proposed method effectively detects and eliminates the dc-bias current.

Power Density Optimization of 700 kHz GaN-Based Auxiliary Power Module for Electric Vehicles

This article proposes a high-power density 1.8 kW auxiliary power module (APM) for electric vehicles (EVs) based on gallium nitride devices. A design procedure for the high-frequency phase-shift full-bridge with current-doubler rectifier using printed circuit board (PCB)-based planar magnetics is proposed. Leakage inductance analysis of the high-frequency pulsewidth-modulation converter is given to achieve both regulation and zero-voltage-switching turn- on . Then, the magnetics optimization procedure for the customized planar core is proposed with a magnetic figure-of-merit concept to meet the high-power density target. Technical considerations are detailed to meet the extreme temperature constraint imposed on the EVs components. Finally, the proposed APM is demonstrated with a switching frequency of 700 kHz and a power density of 8.1 kW/L (132.8 W/in3).

Dual Cell Links for Battery-Balancing Auxiliary Power Modules: A Cost-Effective Increase of Accessible Pack Capacity

This article focuses on the design of a half-full bridge (HFB) balancing link that can reduce the cost of redistributive battery balancer in electrified vehicle applications by combining the functionalities of a battery balancer and auxiliary power module (APM). The benefits of redistributive balancing are quantified based on existing datasets of commercial battery cells. The power rating for the electric vehicle's APM and balancing capability are discussed. A HFB module prototype is designed to validate the proposed concept. How to reduce the current ripple on the battery cells is presented in order to minimize the degradation of the cells due to highly dynamic current. Nickel-manganese-cobalt cells are installed on the module to investigate the balancing performance in real life. The efficiency map is also given for the prototype. Compared with existing balancing methods, the improvement under the same driving cycle is shown in the long-term simulation.

DESIGN AND SIMULATION OF PHASE SHIFTED DC-DC FULL BRIDGE CONVERTER

Electric and hybrid electric vehicle (EV/HEV) architectures require a small DC-DC converter to replace any conventional vehicle’s alternator. The DC-DC converter, also described as the vehicle Auxiliary Power Module (APM), provides power flow between the vehicle high voltage (HV) and low voltage (LV) DC bus. This abstract represents the phase shifted full bridge DC-DC converter scheme to design, simulate DC/DC Converter for a power rating of 80W intended for low power/auxiliary applications in electric vehicles The proposed converter is very beneficial as it can be used for 4 quadrant operation much adaptive to the unknown parameters in the PV system and these unknown parameters are estimated through the adaptation laws in the algorithm which guarantees maximum power extraction possible from the power converter for a PV system. The converter supplies AC current as per requirement. The overall stability of the converter output is analyzed by simulation. The results are compared with other existing converter results for improving power quality even further. The proposed results indicate the robustness of the proposed scheme.

Robust nonlinear burn control in ITER to handle uncertainties in the fuel-line concentrations

Tight regulation of the burn condition in ITER has been proven possible in simulations by the use of robustification techniques even under emulated time-dependent variations in the fuel concentration. One of the most fundamental control problems arising in ITER and future burning-plasma tokamaks is the regulation of the plasma temperature and density to produce a determined amount of fusion power while avoiding possible thermal instabilities. Such problem, known as burn control, requires the development of controllers that integrate all the available actuators. Moreover, the complex burning-plasma dynamics and the uncertain nature of some of its components suggest that nonlinear, robust, burn controllers are necessary. For instance, the deuterium–tritium concentration in the fueling lines may vary over time and the estimation of such variation during operation may be difficult or not even possible. Available actuators for the regulation of the burn condition are auxiliary power modulation, fueling rate modulation, and impurity injection. Also, recent experiments in the DIII-D tokamak have shown that in-vessel coil-current modulation can be used for burn control purposes. The in-vessel coils generate non-axisymmetric magnetic fields that have the capability to decrease the plasma-energy confinement time, which allows for regulation of the plasma energy during positive energy perturbations. In this work, all these actuators are used to design a nonlinear burn controller which is robust to unknown variations in the deuterium–tritium concentration of the fueling lines. Furthermore, fueling rate modulation is not only used to control the plasma density, but also to control the plasma energy, if necessary, by means of isotopic fuel tailoring. The model-based nonlinear controller is synthesized from a zero-dimensional model of the burning-plasma dynamics. A nonlinear simulation study is carried out to illustrate the successful controller performance in ITER-like scenarios in which unknown variations of the deuterium–tritium concentration of the fueling lines are emulated.

Series input multiple outputs flyback auxiliary power supply for input series–output parallel/input series–output series system

A novel series input multiple outputs modular auxiliary power supply and its control strategy are proposed and investigated in this study. It adopts series input multiple outputs connection mode, where multiple auxiliary power modules are connected in series at the input side while they are independent at the output side. This auxiliary power supply can provide power for the control and drive circuits of the power modules in the input series modular system. To ensure input voltage sharing (IVS) between each module, a novel control strategy called master–slave peak current mode control strategy is proposed. With this control strategy, not only IVS can be achieved without any external central controller, but also the output controller and the IVS controller can be decoupled from each other when the system is running in discontinuous conduction mode. The stability of the control strategy is analysed, the effectiveness of the system is discussed and the design process of the controller is given. A two-module auxiliary power supply system prototype is fabricated and tested. The experimental results verify the effectiveness of the proposed system scheme and control strategy.