A novel adaptive energy management strategy is proposed for real-time power split between fuel cells (FCs) and supercapacitors (SCs) in a hybrid electric vehicle in view of the fact that driving ...patterns greatly affect fuel economy. The driving pattern recognition (DPR) is achieved based on the features extracted from the historical velocity window with a multilayer perceptron neural network. After the DPR has been obtained, an adaptive fuzzy energy management controller is utilized for power split according to the required power for vehicle running. In order to prolong the FC lifetime while decreasing the hydrogen consumption, a genetic algorithm is applied to optimize critical factors such as adaptive gains and fuzzy membership function parameters for several standard driving cycles. In the proposed method, the future driving cycles are not required and the current driving pattern can be successfully recognized, demonstrating that less current fluctuations and fuel consumption can be achieved under various driving conditions. Compared with conventional energy management systems, the proposed framework can ensure the state of charge of SCs within the desired limit.
Adoption of the hybrid energy storage system (HESS) brings a bright perspective to improve the total economy of plug-in hybrid electric vehicles (PHEVs). This paper proposes a novel energy management ...method to improve the total economy of PHEV by exploiting the energy storage capability of HESS. Firstly, A cyber-physical energy management framework that enables the synergistic scheduling of fuel engine, battery, and supercapacitor is designed to derive the optimal power distribution strategy for PHEV with HESS. Then, an optimization-based energy management model is established to distribute the vehicle power requirement between the fuel engine and driving motor. The reduction of fuel cost and the mitigation of the battery aging phenomenon are designed as the optimization objectives. In a further stage, an online power distribution algorithm is designed for the optimal control of HESS, where the supercapacitor is used to prolong the battery life. The qualitative and quantitative analyses indicate that both the fuel economy and battery aging cost are sensitive to the power system topology and power distribution algorithm. With the proposed methods, the PHEV total economy can be improved by 8.9% and 6.9% compared to the conventional PHEV structure and power distribution strategy while guarantee the vehicle dynamic performance.
•A novel cyber-physical energy management framework is developed for PHEV with HESS.•An optimization-based energy management model is proposed to improve total economy.•The fuel & electricity economy and battery anti-aging are optimization objectives.•A real-time power distribution algorithm is designed for optimal control of HESS.•The performance is verified on the simulation platform established with actual data.
•Effectiveness-implementation hybrid designs evaluate both outcomes within a study.•Use of these designs help move interventions towards implementation.•Type 1 hybrid designs may be ideal for ...clinical trial researchers to consider.
The traditional research pipeline that encourages a staged approach to moving an intervention from efficacy trials to the real world can take a long time. To address this issue, hybrid effectiveness-implementation designs were codified to promote examination of both effectiveness and implementation outcomes within a study. There are three types of hybrid designs and they vary based on their primary focus and the amount of emphasis on effectiveness versus implementation outcomes. A type 1 hybrid focuses primarily on the effectiveness outcomes of an intervention while exploring the “implementability” of the intervention. A type 2 hybrid has a dual focus on effectiveness and implementation outcomes; these designs allow for the simultaneous testing or piloting of implementation strategies during an effectiveness trial. A type 3 hybrid focuses primarily on implementation outcomes while also collecting effectiveness outcomes as they relate to uptake or fidelity of the intervention. This paper provides an introduction to these designs and describes each of the three types, design considerations, and examples for each.
In this paper, we propose an adaptive control approach with fuzzy logic parameter tuning (AFLPT) for the energy management of electric vehicles that are using fuel cell battery hybrid systems. The ...controller is adaptive to different driving conditions including normal, regenerative, and overload conditions. Specifically, the power flow between the fuel cell (FC) and the Li-ion battery is controlled in real time to maintain the battery state of charge (SOC) at a desirable level while satisfying the FC dynamic constraints. For guaranteeing performance in different driving conditions, the FLPT is integrated with the adaptive controller. Moreover, theoretical properties of the designed controller are analyzed. Simulation and experiment results illustrate the effectiveness of the proposed strategy for FC-battery hybrid systems in electric vehicles.
This paper proposes a new decentralized power management and load sharing method for a photovoltaic (PV)-based, hybrid single/three-phase-islanded microgrid consisting of various PV units, battery ...units, and hybrid PV/battery units. The proposed method is not limited to the systems with separate PV and battery units, and power flow among different phases is performed automatically through three-phase units. The proposed method takes into account the available PV power and battery conditions of the units to share the load among them. To cover all possible conditions of the microgrid, the operation of each unit is divided into five states in single-phase units and seven states in three-phase units and modified active power-frequency droop functions are used according to operating states. The frequency level is used as trigger for switching between the states. Efficacy of the proposed method in different load, PV generation and battery conditions is validated experimentally in a microgrid lab prototype consisting of one three-phase unit and two single-phase units.
The market demand for vehicles with reduced energy consumption, as well as increasingly stringent standards limiting CO2 emissions, are the focus of a large number of research works undertaken in the ...analysis of the energy consumption of cars in real operating conditions. Taking into account the growing share of hybrid drive units on the automotive market, the aim of the article is to analyse the total unit energy consumption of a car operating in real road conditions, equipped with an advanced hybrid drive system of the PHEV (plug-in hybrid electric vehicles) type. In this paper, special attention has been paid to the total unit energy consumption of a car resulting from the cooperation of the two independent power units, internal combustion and electric. The results obtained for the individual drive units were presented in the form of a new unit index of the car, which allows us to compare the consumption of energy obtained from fuel with the use of electricity supported from the car’s batteries, during journeys in real road conditions. The presented research results indicate a several-fold increase in the total unit energy consumption of a car powered by an internal combustion engine compared to an electric car. The values of the total unit energy consumption of the car in real road conditions for the internal combustion drive are within the range 1.25–2.95 (J/(kg·m)) in relation to the electric drive 0.27–1.1 (J/(kg·m)) in terms of instantaneous values. In terms of average values, the appropriate values for only the combustion engine are 1.54 (J/(kg·m)) and for the electric drive only are 0.45 (J/(kg·m)) which results in the internal combustion engine values being 3.4 times higher than the electric values. It is the combustion of fuel that causes the greatest increase in energy supplied from the drive unit to the car’s propulsion system in the TTW (tank to wheels) system. At the same time this component is responsible for energy losses and CO2 emissions to the environment. The results were analysed to identify the differences between the actual life cycle energy consumption of the hybrid powertrain and the WLTP (Worldwide Harmonized Light-Duty Test Procedure) homologation cycle.
For finding a balance between fuel economy and durability of fuel cell hybrid power systems, this article proposes an improved real-time energy management strategy (EMS) based on Pontryagin's minimum ...principle (IM-PMP). We introduce the fuel cell output change rate with weighted coefficient into the Hamiltonian function to limit frequent power fluctuations so as to improve the durability of the fuel cell. In addition, a real-time costate updating method is proposed for unknown driving conditions. This method determines the optimal value of costate according to the real-time state of charge (SOC), which can ensure the online implementation of the EMS and control the SOC of the lithium battery within a certain range. By constructing the hardware-in-the-loop experimental platform, the proposed strategy is compared with the finite state machine (FSM) strategy. Compared with FSM, the hydrogen consumption of the IM-PMP strategy is reduced by 10.1%, and the fuel cell operating stress is reduced by 38.3%. The SOC of the lithium battery is maintained at around 0.6. The experimental results verify the superiority of the proposed EMS.
The idea of electric propulsion for transportation is not new; indeed, the first cars, nearly 200 years ago, were electric. However, our dependence on fossil fuels over the last 100 years is now ...being questioned, and as a global society, we are moving toward more-electric transportation solutions. Electric propulsion of aircraft is part of this trend, either all-electric or through a large variety of the proposed hybrid propulsion systems. This article considers some of these systems, their technological requirements, and the ongoing research and development in motors and drives necessary to make this technological change a feasible option for the future of passenger flight.
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