Search

To improve vehicle performance and energy utilization, a novel planetary gear set based flywheel hybrid electric powertrain (PGS-FHEP) is proposed. The PGS-FHEP involves an internal combustion engine, a planetary gear set that integrated a control motor and an energy storage flywheel, which combines the high efficiency of the mechanical flywheel energy storage system with the flexible and controllable characteristics of the electric motor. The powertrain is analyzed and modeled using lever analogy method, and a rule-based control strategy is designed and verified under different test cycles. The simulation results indicate that compared with the traditional manual transmission vehicle, the fuel economy of the vehicle equipped with PGS-FHEP can be improved by more than 50%, and the acceleration performance can be increased by 28.01%. Up to 60.61% of vehicle kinetic energy can be recovered by PGS-FHEP, among which 37.85% can be directly captured by the energy storage flywheel. In addition, the battery charging power is reduced, which is beneficial to prolong the battery life.

Copyright of Journal of Polytechnic is the property of Journal of Polytechnic and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Concerns about climate change, air pollution, and the depletion of oil resources have prompted authorities to enforce increasingly strict rules in the automotive sector. There are several benefits to implementing fuel cell hybrid vehicles (FCHV) in the transportation sector, including the ability to assist in reducing greenhouse gas emissions by replacing fossil fuels with hydrogen as energy carriers. This paper examines different control strategies for optimizing the power split between the battery and PEM fuel cell in order to maximize the PEM fuel cell system efficiency and reduce fuel consumption. First, the vehicle and fuel cell system models are described. A forward approach is considered to model the vehicle dynamics, while a semi-empirical and quasi-static model is used for the PEM fuel cell. Then, different rule-based control strategies are analyzed with the aim of maximizing fuel cell system efficiency while ensuring a constant battery state of charge (SOC). The different methods are evaluated while the FCHV is performing both low-load and high-load drive cycles. The hydrogen consumption and the overall fuel cell system efficiency are considered for all testing conditions. The results highlight that in both low-load cycles and high-load cycles, the best control strategies achieve a fuel cell system efficiency equal or greater to 33%, while achieving a fuel consumption 30% less with respect to the baseline control strategy in low-load drive cycles. [ABSTRACT FROM AUTHOR]

Concerns about climate change, air pollution, and the depletion of oil resources have prompted authorities to enforce increasingly strict rules in the automotive sector. There are several benefits to implementing fuel cell hybrid vehicles (FCHV) in the transportation sector, including the ability to assist in reducing greenhouse gas emissions by replacing fossil fuels with hydrogen as energy carriers. This paper examines different control strategies for optimizing the power split between the battery and PEM fuel cell in order to maximize the PEM fuel cell system efficiency and reduce fuel consumption. First, the vehicle and fuel cell system models are described. A forward approach is considered to model the vehicle dynamics, while a semi-empirical and quasi-static model is used for the PEM fuel cell. Then, different rule-based control strategies are analyzed with the aim of maximizing fuel cell system efficiency while ensuring a constant battery state of charge (SOC). The different methods are evaluated while the FCHV is performing both low-load and high-load drive cycles. The hydrogen consumption and the overall fuel cell system efficiency are considered for all testing conditions. The results highlight that in both low-load cycles and high-load cycles, the best control strategies achieve a fuel cell system efficiency equal or greater to 33%, while achieving a fuel consumption 30% less with respect to the baseline control strategy in low-load drive cycles.

• A rule-based control strategy was developed to schedule a Carnot battery operation. • Coupling of a Carnot battery and district heating allows for thermal peak shaving. • Sensitivity analysis by varying integrated system's key parameters was performed. • The Carnot battery allows for a 47 % downsizing of the district heating substation. • 13 m3 optimal storage size for reference 10 kWe-sized Carnot battery was assessed. To encourage decarbonization and promote a widespread penetration of renewable energy sources in all energy sectors, the development of efficient energy storage systems is essential. Interesting grid-scale electricity storage technologies are the Carnot batteries, whose working principle is based on storing electricity in the form of thermal energy. The charging phase is performed through a heat pump cycle, and the discharging phase is conducted through a heat engine. Since both thermal and electric energy flows are involved, Carnot batteries can be adopted to provide more flexibility in heat and power energy systems. To this aim, efficient scheduling strategies are necessary to manage different energy flows. In this context, this work presents a detailed rule-based control strategy to schedule the synergetic work of a 10-kWe reversible heat pump/organic Rankine cycle Carnot battery integrated to a district heating substation and a photovoltaic power plant, to satisfy a local user's thermal and electric demand. The coupling of a Carnot battery with a district heating substation allows for shaving the thermal demand peaks through the thermal energy stored in the Carnot battery storage, allowing for a downsizing of the district heating substation, with a considerable reduction of the investment costs. Due to the multiplicity of the involved energy flows and the numerous modes of operation, a scheduling logic for the Carnot battery has been developed, to minimize the system operating costs, depending on the boundary conditions. To investigate the influence of the main system design parameters, a detailed and accurate model of the Carnot battery is adopted. Two variants of the reference system, with different heat pump cold source arrangements, are investigated. In the first case, the heat pump absorbs thermal energy from free waste heat. In the second case, the heat pump cold source is the return branch of the district heating substation. The simulation results show that, in the first case, the Carnot battery allows the downsizing of the district heating substation by 47 %, resulting in an annual gain of more than 5000 €. About 70 % of the economic benefit is due to the possibility of reducing the power size of the district heating substation, which can be from 300 to more than 500 kW. The payback period is estimated to be lower than 9 years, while in the second case, the Carnot battery is not able to provide a gain. Eventually, the influence of some parameters, such as the photovoltaic power plant surface, the storage volume, the electricity price profile and the reversible heat pump/organic Rankine cycle specific investment cost, on the techno-economic performance of the system, is investigated through a wide sensitivity analysis. According to the results, the photovoltaic panels surface does not significantly affect the economic gain, while the storage capacity strongly affects the system scheduling and the operating costs. Indeed, it is possible to identify that 13 m3 is the size of the storage volume that minimizes the payback period to 8.22 years, for the considered application. An increase in the electricity price without an increase in the thermal energy price leads to a decrease in economic gain because the benefit brought by the downsizing of district heating is less significant on the economic balance. The specific investment cost of the reversible heat pump/organic Rankine cycle does not influence the operating cost; thus, it does not change the Carnot battery management, nor the economic gain. The specific investment cost affects the payback period, which increases from 8.6 years for a specific cost of 2000 €/kWe to 15.7 years for a specific cost of 5000 €/kWe. [ABSTRACT FROM AUTHOR]

The cyber-physical nature of electric power systems has increased immensely over the past decades, with advanced communication infrastructure paving the way. It is now possible to design wide-area controllers, relying on remote monitor and control of devices that can tackle power system stability problems more effectively than local controllers. However, their performance and security relies extensively on the communication infrastructure and can make power systems vulnerable to disturbances emerging on the cyber side of the system. In this study, the authors investigate the effect of communication delays on the performance of wide-area damping controllers designed to stabilise oscillatory modes in a cyber-physical power system (CPPS). They propose a rule-based control strategy that combines wide-area and traditional local stabilising controllers to increase the performance and maintain the stable operation of CPPS. The proposed strategy is validated on a reduced CPPS equivalent model of Great Britain.

With the rapid development of renewable energy technology, marine current energy is treated as the most desirable form of ocean energies. Due to the nature of marine current energy, simple structure, high reliability, and good control performance are the primary consideration for the energy management strategy. This paper proposes an energy management control strategy based on rules to compensate for the fluctuating power caused by tidal motion. The hybrid energy storage system composed of vanadium redox flow battery (VRB) is applied to reallocate power. Supercapacitor banks (SCBs) are applied as the auxiliary power source to absorb or release the required power according to energy management strategy based on control rules in the marine current power system. SCB makes the grid-connected power track the grid command power and also improves the operational efficiency of the vanadium redox flow battery (VRB). VRB compensates for the low-frequency fluctuating power caused by tidal motion and plays an important role in compensating for the difference in power between the grid-connected power and the grid command power to ensure the reliability of the marine current power system. A simulation model of a 3 MW marine current power system is built to verify the effectiveness of the energy management strategy based on the real marine current velocity data.

Online optimal control of a multicarrier home energy system, including a fuel cell (FC) with combined heat and power functionality, a furnace, and a battery as an energy storage system, is presented in this paper. An appropriately defined objective function (OF) is formulated to address the operation costs of the home energy system by considering the electrical time-of-use price and time-varying electrical and thermal demand. To determine the optimal control strategy of the FC, the defined OF is solved analytically to reach a closed-form solution for the optimal operation of the FC, which results in the global optimum compared with the near-optimal point in previous works of FC scheduling. To attain the whole system optimal operation, a rule-based solution for the optimal operation of the battery is proposed according to its characteristics. The proposed method is applied to a realistic case study including real load demand and experimentally verified data of the FC. The results are compared with previous approaches, in which optimization techniques have been used to achieve near-optimal scheduling of FC with/without a battery. It is shown that the proposed control strategy results in more exact scheduling and can be applied successfully in real applications. [ABSTRACT FROM PUBLISHER]

• Combining battery and H 2 storage achieves the highest self-sufficiency. • Combining battery and H 2 storage is cost-effective option to minimize CO 2 emission. • Recovered heat from a PEMFC improves overall H 2 storage system efficiency. • The storage performance is evaluated under different heating system scenarios. An H 2 storage system (i.e., an electrolyzer, H 2 tank, and a fuel cell) has received attention for seasonal storage. The H 2 storage system can improve energy conversion efficiency by utilizing recovered heat from the fuel cell in a residential application. This study investigated the potential of a battery-H 2 storage system using the recovered heat to maximize energy self-sufficiency in residential buildings. The entire energy supply network consisted of a photovoltaic, electric heating system, and energy storage systems (i.e., battery, H 2 storage system, and heat tank). To investigate the self-sufficiency performance, four storage cases (i.e., no storage, battery-only, H 2 storage system, and battery-H 2 storage system cases) were introduced to the residential buildings under two electric heating system scenarios (i.e., electric boiler and heat pump system). In addition, these cases were evaluated in terms of economic and environmental performance, and the effects of battery efficiency uncertainty and battery types on energy network performance were analyzed. The findings showed that the battery-H 2 storage system achieved the highest self-sufficiency while reducing the battery capacity because the H 2 storage system compensated for a self-discharge loss of the battery for seasonal storage. Accordingly, the battery-H 2 storage system was the most cost-effective option for minimizing CO 2 emissions in residential buildings. When the battery was used with the H 2 storage system, improving battery energy conversion efficiency was more effective than battery self-discharge rate in reducing CO 2 emissions further. In addition, a lead-acid battery was more cost-effective than a lithium-ion battery but showed low potential to reduce CO 2 emissions and was disadvantageous in terms of physical size. [ABSTRACT FROM AUTHOR]

Recently, second-life battery systems have received a growing interest as one of the most promising alternatives for decreasing the overall cost of the battery storage systems in stationary applications. The high-cost of batteries represents a prominent barrier for their use in traction and stationary applications. To make second-life batteries economically viable for stationary applications, an effective power-electronics converter should be selected as well. This converter should be supported by an energy management strategy (EMS), which is needed for controlling the power flow among the second-life battery modules based on their available capacity and performance. This article presents the design, analysis and implementation of a generic energy management strategy (GEMS). The proposed GEMS aims to control and distribute the load demand between battery storage systems under different load conditions and disturbances. This manuscript provides the experimental verification of the proposed management strategy. The results have demonstrated that the GEMS can robustly handle any level of performance inequality among the used-battery modules with the aim to integrate different levels (i.e., size, capacity, and chemistry type) of the second-life battery modules at the same time and in the same application. [ABSTRACT FROM AUTHOR]

Nowadays, hybrid power excavators are an active research subject in the construction machinery area. The primary focus of this study is to investigate the control strategy for improving the stability of a powertrain for compound hybrid power excavators. First, the power flow and the dynamics of the powertrain of compound hybrid power excavators are analysed. It is concluded that the control strategy for compound hybrid power excavators has to guarantee the charge and discharge priority for operation of the swing and the boom lowering. Otherwise, large-scale switches of the operation point of the engine have to be performed in order to keep the state of charge in the appropriate range, which results in worse stability of the powertrain. Then, an improved rule-based control strategy is presented, which incorporates a load torque distributor, a charge-sustaining strategy and a dynamic torque compensator. The simulation model of a 20 ton compound hybrid power excavator, namely the ZE205E hybrid, is established. The improved rule-based control strategy, the thermostat control strategy and the control strategy presented by Yoo in 2009 are compared with respect to the stability of the powertrain and the fuel consumption through simulations. The simulation results show that the improved rule-based control strategy is best for the stability; however, for the fuel consumption, the improved rule-based control strategy is better than the thermostat control strategy but poorer than the control strategy described by Yoo. Taking into overall consideration the stability of the powertrain and the fuel consumption, the improved rule-based control strategy presented in this paper is more applicable for compound hybrid power excavators. [ABSTRACT FROM AUTHOR]

Recently, second-life battery systems have received a growing interest as one of the most promising alternatives for decreasing the overall cost of the battery storage systems in stationary applications. The high-cost of batteries represents a prominent barrier for their use in traction and stationary applications. To make second-life batteries economically viable for stationary applications, an effective power-electronics converter should be selected as well. This converter should be supported by an energy management strategy (EMS), which is needed for controlling the power flow among the second-life battery modules based on their available capacity and performance. This article presents the design, analysis and implementation of a generic energy management strategy (GEMS). The proposed GEMS aims to control and distribute the load demand between battery storage systems under different load conditions and disturbances. This manuscript provides the experimental verification of the proposed management strategy. The results have demonstrated that the GEMS can robustly handle any level of performance inequality among the used-battery modules with the aim to integrate different levels (i.e., size, capacity, and chemistry type) of the second-life battery modules at the same time and in the same application.

Abstract: In this study, rule-based control strategies were proposed according to the result of the process state diagnosis. Multivariate statistical techniques were used to derive the diagnosis results that included comprehensive information for the current process state. Based on the diagnosis result, the quantitative control setpoint could be calculated by using the optimized mathematical model. The developed process diagnosis procedure and the control strategies were applied in a pilot-scale A2/O (anaerobic/anoxic/oxic) process. The target variables in the proposed rule-based control strategies according to the process state diagnosis were the effluent NH4–N and NO X –N components. From the application of these rule-based control strategies according to the process state diagnosis, the percentages of groups 3 and 4, which were considered the abnormal process state, were decreased by about 53.8% compared to the no-control case. In addition, the maintenance interval of the control action ranged from 4h to 25h. Effluent NH4–N and NO X –N concentrations lower than the target values were maintained by applying the proposed rule-based control strategies according to the process state diagnosis. Moreover, frequent changes of the process operating state were minimized and the electrical equipment load was reduced. [Copyright &y& Elsevier]

Among the general problematic of the HEV power trains, the most critical point is the determination of the power-split ratio between the mechanical and the electrical paths, known as the energy management strategy (EMS). Many EMS are proposed in the literature, and can be grouped in two categories: the local optimization EMS and the global optimization EMS. The local optimization category corresponds to the EMS based on human expertise and the knowledge of the power train components efficiency maps. Thus, the local optimization EMS manages the power train operations by referring to predefined rules. The drawback of such strategies is that it brings an instantaneous fuel consumption optimization, and does not fully optimize the fuel consumption over the whole trip. Therefore, additional fuel savings are still possible. This paper presents an overall optimized predictive EMS for the Toyota Hybrid System (THS-II) power train of the Prius. The proposed EMS is based on Dynamic Programming (DP), where the prior knowledge of the route is required in order to predetermine the power-split ratio and optimize the fuel consumption for the whole predicted route. The DP EMS proposed for the THS-II power train is designed with a very short computation time, intended to be implemented in real-time applications. The potential of this DP-controller in reducing fuel consumption on regulatory cycles are computed and compared to a rule-based controller and to the Prius published fuel consumption results. Finally, the fuel reduction enhancements of the DP-controller are computed for real road tests achieved on a MY06 Prius in Ile-de-France, by comparing to the associated observed consumption measurements. [ABSTRACT FROM AUTHOR]

The high cost of the powered prosthetic leg is one of the challenges for the lower‐limb amputees in developing countries. This Letter presents a robust design and simplified control strategy for a cost‐effective magnetorheological‐damper‐based prosthetic leg for transfemoral amputees. Herein, a simple sensing technique having an accelerometer and two force‐sensing resistors is incorporated to obtain the gait events. Based on gait phase detection, a simplified if‐else rule‐based control strategy is implemented. A comparison between angles of prosthetic and intact knee is presented to demonstrate the effectiveness of the proposed design. [ABSTRACT FROM AUTHOR]

With the rapid development of renewable energy technology, marine current energy is treated as the most desirable form of ocean energies. Due to the nature of marine current energy, simple structure, high reliability, and good control performance are the primary consideration for the energy management strategy. This paper proposes an energy management control strategy based on rules to compensate for the fluctuating power caused by tidal motion. The hybrid energy storage system composed of vanadium redox flow battery (VRB) is applied to reallocate power. Supercapacitor banks (SCBs) are applied as the auxiliary power source to absorb or release the required power according to energy management strategy based on control rules in the marine current power system. SCB makes the grid-connected power track the grid command power and also improves the operational efficiency of the vanadium redox flow battery (VRB). VRB compensates for the low-frequency fluctuating power caused by tidal motion and plays an important role in compensating for the difference in power between the grid-connected power and the grid command power to ensure the reliability of the marine current power system. A simulation model of a 3 MW marine current power system is built to verify the effectiveness of the energy management strategy based on the real marine current velocity data. [ABSTRACT FROM AUTHOR]