Regenerative Braking Energy Recovery Research Articles

Theoretical study on energy recovery rate of regenerative braking for hybrid mining trucks with different parameters

Based on the theory of the traditional hydraulic braking system of mining trucks and under the condition of safety, in order to maximize the regenerative braking energy recovery of hybrid mining trucks, a regenerative braking force distribution and control strategy for rear wheel parallel hybrid mining truck is proposed in this paper. Influences of charging current, battery state of charge value and braking force distribution on regenerative braking energy recovery is studied. ADVISOR is used for truck modeling and simulation under typical mining braking conditions. The results show that the maximum regenerative braking energy recovery rate is 65.01% when the initial charging current is 10A, 30A, 50A and 70A, respectively. The results indicate that the regenerative braking control strategy can solve the problems of braking safety performance and maximize the regenerative braking recovery rate.

Optimization research on hybrid energy storage system of high‐speed railway

The regenerative braking energy generated during the braking of high-speed trains affects the power quality of the power grid. Recovery of regenerative braking energy is problem that needs to be solved urgently. The regenerative braking energy of high-speed railway features high power and high energy. It is difficult to recover it only by using high power density supercapacitors or high energy density batteries. In this paper, a hybrid energy storage system (HESS) composed of supercapacitors and lithium-ion batteries and its optimal configuration method are proposed for the purpose of obtaining maximum economic benefits for railroad systems. Then the economic benefits when using the HESS and the single energy storage system are compared from the perspective of whether the regenerative braking energy is fully recycled or not. Finally, a simulation analysis with actual load of a high-speed railway station is performed. The highest benefit is achieved when the regenerative braking energy is partially recovered by the HESS, which can save 3% of the total cost per day and pay back the cost in eight years.

A research on regenerative braking energy recovery: A case of Addis Ababa light rail transit

In Ethiopia, strong dependency on hydropower presents risks to energy security issues due to the vulnerability of the country to recurrent and prolonged droughts. The problem is also linked to trade-off in drinking, industrial and agricultural water needs; the impact of silt and sedimentation on lakes and reservoirs; and disputes over water resources. The Ethiopian railway industry is at the core of all these energy issues, for example the new preference for the supply of energy for traction purposes has been given to hydropower. However, power cuts continue, leading to uncertainty. In addition, separate railway repair units are also starving for their energy demands. This clearly has negative effect on the overall performance of the railway industry. Furthermore, as energy requirements rise, railways will have to fight for the scarce energy with other priority sectors. Therefore, energy is the last big issue to be overcome by industry in the coming decades. In this regard, regenerative energy could be one of the promising energy source to maximize energy efficiency of the railway. Consequently, this paper has assessed and examined the main factors that influence regenerative braking energy recovery as well as evaluated regenerative energy potential of Addis Ababa light rail transit. To this end, a mathematical model, consisting of a series of empirical formulas have been developed and detail analysis has been performed. To verify the empirical formulas and mathematical models a comprehensive simulation model of Addis Ababa light rail transit system using Mathlab/Simulink has been developed. Consequently, the simulation results confirmed the consistency of the proposed mathematical model. Finally, based on different scenarios; this paper concluded that, it is possible to save up to 32% of the electrical energy for the light rail transit network in Addis Ababa (AALRT).

Segmented Power Supply Preset Control Method of High-Speed Rail Contactless Traction Power Supply System considering Regenerative Braking Energy Recovery

For high-speed rail with high energy consumption, the recovery and utilization of regenerative braking energy is essential to improve the energy consumption of high-speed rail. As a technical link, the energy bidirectional feed inductively coupled power transfer (ICPT) system can realize the regenerative braking energy recovery of the contactless traction power supply system. Furthermore, considering that the braking energy of the high-speed rail is the largest when entering the station during the whole line operation, the braking section of the station is mainly considered. This paper proposes a preset control method for segmented power supply of the energy bidirectional feed ICPT system considering regenerative braking energy recovery. By establishing the steady-state mathematical model of the bidirectional ICPT system, the influence of the internal phase-shift angles φ1 and φ2 and the external phase-shift angle γ on the operating state of the system is analyzed. To realize system synchronization under the operation of EMUs, a train braking model is established through force analysis, and a power preset controller is designed to realize the synchronous control of the power flow of the bilateral system. According to the braking process of the train entering the station, the switching control method of the segment coil under the different conditions of the single train entering the station and the multitrain entering the station is proposed to ensure the reliability and flexibility of the train power supply. The simulation results of the 350 kW ICPT system simulation model show that the system can operate stably when the power transmission simulation is switched, and the transmission efficiency can reach 89%, which proves the feasibility of the control method. Energy-saving estimates show that a single train can recover about 200–300 kWh of electric energy during single braking. The comparison with the measured data verifies the accuracy of the modeling in this paper.

Stability Analysis of a DC MicroGrid for a Smart Railway Station Integrating Renewable Sources

A low-level distributed nonlinear controller for a DC MicroGrid integrated in a Smart Railway Station capable to recover trains’ braking energy is introduced in this paper. The DC MicroGrid is composed by a number of elements: two different types of renewable energy sources (regenerative braking energy recovery from the trains and photovoltaic panels), two kinds of storages acting at different time scales (a battery and a supercapacitor), a DC load representing an aggregation of all loads in the MicroGrid, and the connection with the main AC grid. The nonlinear model of the MicroGrid is introduced, and a complete stability analysis is investigated to the purpose to meet power balance and grid voltage stability requirements. An Input-to-State Stability (ISS)-like Lyapunov function is obtained with a System-of-Systems approach, and it is utilized to develop the control laws for the converters in order to fulfill the dedicated objective each of them has. Simulation results, showing the desired grid behavior using the proposed nonlinear control laws, are introduced and compared with classical Proportional Integral (PI) linear controllers, with respect to performances and parametric robustness. The DC MicroGrid is shown to be able to operate braking energy recovery while performing load feeding and renewable energy integration and guaranteeing a proper DC voltage profile.

Research on Anti-Lock Braking Control Strategy of Distributed-Driven Electric Vehicle

Aiming at the problem of the stability of distributed-driven electric vehicles under braking conditions and the recovery of regenerative braking energy, a novel compound brake anti-lock braking control strategy based on wheel slip rate control is proposed. This article takes distributed-driven electric vehicles as the research object. From the perspective of the single-wheel braking dynamic model of the car, the method of designing a non-linear state observer is used to observe the changing longitudinal braking force of the wheel, and then to achieve the estimation of the optimal slip rate. Using the improved adaptive sliding mode controller to achieve effective control of the optimal slip rate to improve the chattering problem of sliding mode control. According to the output of the controller, combined with the motor brake and hydraulic brake system of the car, a composite brake anti-lock control system is designed. The joint simulation is carried out in the environment of MATLAB and CARCISM. The simulation results show that the control method studied can effectively estimate and control the optimal slip rate under various complex road surfaces, and realize the safety and stability of electric vehicle brake control.

Research on multi-mode regenerative braking energy recovery of electric vehicle with double rotor hub motor

In this study, a new type of double rotor hub motor is proposed. Then, its structure, the working principle as well as the regenerative braking energy recovery modes are described. In detail, three kinds of regenerative braking energy recovery modes, i.e., double motor regenerative braking mode, single inner motor regenerative braking mode and single outer motor regenerative braking mode, are introduced. The mathematical models of single wheel dynamics model and double rotor hub motor model are established. The three kinds of braking energy recovery modes are compared and the simulation results show that, by using the sliding mode control strategy, on the condition that the maximum braking energy recovery of the motor is satisfied, the hydraulic braking torque can make corresponding response according to the change of the regenerative braking torque of the motor. At the same time, antilock braking of the wheel is achieved.

Research on multi-mode regenerative braking energy recovery of electric vehicle with double rotor hub motor

Research on multi-mode regenerative braking energy recovery of electric vehicle with double rotor hub motor

Torque Coordinated Control of Four In-Wheel Motor Independent-Drive Vehicles With Consideration of the Safety and Economy

How to reasonably coordinate and control the torque of four wheels to enhance vehicle performance is an important research problem of the four in-wheel-motor independent-drive electric vehicle (4MIDEV). In this paper, a coordinated hierarchical control strategy for the dynamic wheel torque of 4MIDEV steering is proposed, which considers both safety and energy-saving performance. The innovation of this paper lies in two new valuable algorithms in the top and bottom level controller, respectively. Besides the optimal control method on the basis of the 2-degree of freedom (DoF) ideal model in the top level controller, a novel model predictive control method based on the 7-DoF dynamic model is put forward to obtain two virtual generalized forces required during vehicle driving. In the bottom level controller, a novel optimal allocation (OA) algorithm is brought forward to improve the safety and energy-saving performance. The tire stability margin and the electric power of driving system balancing the driving energy consumption and regenerative braking energy recovery are considered in the quadratic objective function of OA algorithm at the same time. Carsim-Simulink joint simulation results under open-loop and closed-loop steering conditions illustrate that, compared with the 2-DoF LQR control method, the 7-DoF MPC method could effectively improve vehicle handling stability and safety. The bottom optimal allocation algorithm can not only improve the vehicle handling stability, but also make the driving system more energy-saving.

STUDY ON THE ALLOCATION STRATEGY OF REGENERATIVE BRAKING FORCE WITH A DRIVER’S INTENTION

The regenerative braking energy recovery system of electric vehicle can effectively improve its mileage. In this paper, we took the front-drive EV as the object to analyze the braking force allocation during its braking process. After considering ECE regulation, the motor peak torque and battery charging power as the main restrictive conditions and combining them with driver braking intensity discrimination characteristics, a new control strategy of regenerative braking force allocation was proposed for the vehicle. Then, simulation model was established on the MATLAB/Simulink software platform. At the same time, the initial velocity is 30km/h, 60km/h and 100km/h respectively, and the braking intensity is 0.1 and 0.5 respectively, which were set as simulation conditions. The simulation results of the strategy were compared to that of ideal braking force allocation strategy under the middle braking intensity condition. The results show that this control strategy can effectively achieve the braking energy recovery, and the efficiency at each initial braking speed of low, medium and high speeds is higher than that of ideal braking force allocation strategy.

Energy transfer and utilization efficiency of regenerative braking with hybrid energy storage system

In order to increase the recovery and utilization efficiency of regenerative braking energy, this paper explores the energy transfer and distribution strategy of hybrid energy storage system with battery and ultracapacitor. The detailed loss and recovery of energy flow path are analyzed based on the driving/regenerative process of dual supply electric vehicle. Considering the charge-discharge loss of ultracapacitor and battery as well as DC/DC converter loss, a distribution strategy of comprehensive efficiency optimum is proposed for power allocation to maximize energy recovery and utilization efficiency. The quantitative formulas suitable for HESS are deduced to evaluate the regenerative energy recovery rate. Through comparing different power allocation strategies and regenerative braking strategies, it is verified that the proposed allocation strategy can improve the comprehensive energy utilization efficiency of energy storage system.

Research on Regenerative Braking of Pure Electric Mining Dump Truck

When the pure electric mining dump truck is working, it mainly ascends the slope at full load and descends the slope at no load. The loading state of the vehicle and the slope of the road will directly affect its axle load distribution and braking force distribution. In this paper, the slope dynamics analysis of the pure electric double-axle four-wheel drive mining dump truck was carried out. Based on the regenerative braking priority strategy, four regenerative braking control methods were developed based on the Matlab/Simulink platform and ADVISOR 2002 vehicle simulation software to study the ability of regenerative braking energy recovery and its impact on vehicle economic performance. The simulation results show that the regenerative braking priority control strategy used can maximize the regenerative braking force of the vehicle; the regenerative energy recovery capability of pure electric mining dump truck is proportional to the regenerative braking force that can be provided during braking; the two-axis braking strategy based on the I curve and the β line can make full use of the front and rear axle regenerative braking force when the braking intensity is large, and recover more braking energy; under road drive cycle, the single-axis braking force required to the braking strategy based on the maximized front axle braking force is the largest among all strategies, the motor braking efficiency is the highest, and the recovered braking energy is the most. For the studied drive cycle, the regenerative braking technology can reduce the vehicle energy consumption by 1.06%–1.56%. If appropriate measures are taken to improve the road surface condition and reduce the rolling resistance coefficient from f = 0.04 to f = 0.02, the regenerative braking technology can further reduce the vehicle energy consumption to 4.76%–5.73%. The economic performance of the vehicle is improved compared to no regenerative braking. In addition, the vehicle loading state and the driving motor working efficiency also directly affect the regenerative braking energy recovery capability of the pure electric mining truck.

Maximizing Regenerative Braking Energy Recovery of Electric Vehicles Through Dynamic Low-Speed Cutoff Point Detection

This paper introduces a novel approach for dynamically detecting the lowest speed threshold at which regenerative braking is effective in electric vehicles (EVs). The control approach is based on real-time sensing of the motor controller dc link current and disabling regenerative braking when current changes direction while the motor is operating as a generator. Various factors influencing the regenerative braking capability of EVs at low speed are discussed, and the simulation studies are carried out to illustrate the effect of each factor on the displacement of the low-speed threshold. Based on the results obtained from the simulation studies, a dynamic low-speed cutoff point (LSCP) detection method is proposed. This method requires no hardware modification to the vehicle braking architecture and can be implemented solely by modifying the brake controller. The proposed method is tested on an experimental EV test platform for a predetermined drive cycle. It is shown that in comparison to considering a constant low-speed threshold during braking, the amount of energy recaptured through the regenerative braking process can be improved by taking advantage of the proposed method.

Regenerative braking energy recovery strategy based on Pontryagin's minimum principle for fell cell/supercapacitor hybrid locomotive

A regenerative braking energy recovery strategy based on pontryagin's minimum principle (PMP) for Fuel Cell (FC)/Supercapacitor (SC) hybrid power locomotive was proposed in this paper. In the proposed strategy, the dynamic coefficient λ is used in PMP during the traction state of the locomotive, which makes system transient hydrogen consumption minimum. What's more, during locomotives brake state, according to the known parameters of SCs and operation indicators, an optimized braking speed curve can also be obtained which has maximum brake recovery rate. The results are obtained from RT-LAB platform testify that the proposed strategy is able to maximize SC absorption braking energy, and the energy recovery rate improves and maintains SC state of charge (SoC) in a reasonable and safe range, and decreases brake resistors energy consumption in the braking process.

Optimization of Control Variables and Design of Management Strategy for Hybrid Hydraulic Vehicle

The article deals with optimization of control variables and design of management strategy for a hybrid hydraulic vehicle in parallel configuration. Conventionally driven delivery truck with experimentally verified data from the previous research is taken as a starting base and benchmark for comparison of the benefits of hybridization. Optimization of control variables is carried out using dynamic programming (DP) algorithm to gain insight into optimum operation of the driveline and minimum possible fuel consumption for five different driving cycles. Two rule based management strategies are given and compared, one of which is improved and innovative, based on the knowledge gained from DP results. Hybrid driveline can reduce fuel consumption from 5% to 30% depending on the driving cycle. More dynamic cycles with lot of "stop-and-go" events score greater reduction. Innovative management strategy has achieved a similar distribution of internal combustion engine (ICE) operating points as DP optimization but this did not result in a consistent reduction of fuel consumption compared to basic management strategy for all cycles. That is explained by the state of charge (SoC) behaviour and reducing the potential for recovery of regenerative braking energy.

A Novel Power Distribution System Employing State of Available Power Estimation for a Hybrid Energy Storage System

This paper presents a novel power distribution system (PDS) algorithm to be employed in a hybrid energy storage system (HESS). PDS is responsible for sharing the demand power between energy storage modules, which are battery and ultracapacitor (UC) in this study. The challenge in designing PDS is in assigning the power-share between these modules. A state of available power technique is proposed based on the prediction of the power limitations for a predefined time frame in the future. Another PDS based on the UC state of charge is developed. Various design variables are defined that affect the performance of the PDS. The genetic algorithm optimization technique is employed to determine the design variables. The proposed PDS techniques along with an energy storage system (ESS) consisting of a single battery and a basic PDS system is studied on a 12-kW electric motorcycle during the standard FTP and the New York City Cycle (NYCC) driving cycles. Battery lifetime, vehicle range, and regenerative braking energy recovery functions for the proposed methods compared with the ESS are improved by 2.6 times, 25%, and 29%, respectively. The results suggest that employing the proposed novel PDSs improves the performance of the HESS significantly.

Research on regenerative braking energy recovery system of electric vehicles

Regenerative braking energy recovery is a remarkable feature of new energy vehicles. This paper introduced a method to realize energy recovery by using variable voltage system as motor drive system, which can realize the braking energy regeneration of large-scale change of speed. At the same time, the test of regenerative braking energy recovery was performed to analyze the regenerative performance of new energy vehicles. The effectiveness of regenerative braking system for electric vehicles is verified, which provides the new way to further improve the regenerative braking performance of new energy vehicles.

A Novel Hybrid DC Traction Power Supply System Integrating PV and Reversible Converters

A novel hybrid traction power supply system (HTPSS) integrating PV and reversible converter (RC) is proposed. PV is introduced to reduce the energy cost and increase the reliability of power systems. A reversible converter can achieve multiple objectives including regenerative braking energy recovery, PV energy inverting, DC voltage regulation and power factor improvement. In this paper, the topology and operating modes of the HTPSS are first introduced. Three-level boost converter (TLBC) is employed in the PV system. A double closed-loop control scheme considering both maximum power point tracking (MPPT) and midpoint potential balancing (MPB) is recommended. The reversible converter adopts a multi-modular topology and the independent control for active power and reactive power has been achieved by a current decoupling control. According to the working characteristic of each device, a coordinated control strategy is designed, and four basic principles are given. A system simulation model containing a hybrid traction substation and a train was built, and comprehensive simulations under multi-scenario were carried out. The results show that the reversible converter can accomplish PV energy inversion, DC voltage regulation, regenerative braking energy recovery and power factor improvement, by which a high utilization rate and energy-saving effect can be obtained.

A Regenerative Braking Control Strategy for EVs Based on Real-Time Dynamic Loading of the Wheels

This paper proposes a regenerative braking control strategy based on real-time dynamic loading (RTDL) of wheels. Based on the nonlinear relationship between a spring’s resilience and displacement, this paper establishes 7-degrees of freedom (DOF) full vehicle model with nonlinear suspension. Then, a method based on suspension deformation is devised to calculate the wheels’ dynamic load, and RTDL is used to calculate the braking force of the front and rear wheels. With the braking intensity and the battery state of charge (SOC) as input variables and the desired regenerative braking force as an output variable, we establish a regenerative braking control strategy based on RTDL and simulate it in ADVISOR software. Results show that the designed control strategy effectively improves the regenerative braking energy recovery efficiency by assuring braking stability, and verifies the rationality and feasibility of the proposed control strategy.

Development of Brake System and Regenerative Braking Cooperative Control Algorithm for Automatic-Transmission-Based Hybrid Electric Vehicles

In this paper, a brake system for an automatic transmission(AT)-based hybrid electric vehicle (HEV) is developed, and a regenerative braking cooperative control algorithm is proposed, with consideration of the characteristics of the brake system. The brake system does not require a pedal simulator or a fail-safe device, because a hydraulic brake is equipped on the rear wheels, and an electronic wedge brake (EWB) is equipped on the front wheels of the vehicle. Dynamic models of the HEV equipped with the brake system developed in this study are obtained, and a performance simulator is developed. Furthermore, a regenerative braking cooperative control algorithm, which can increase the regenerative braking energy recovery, is suggested by considering the characteristics of the proposed hydraulic brake system. A simulation and a vehicle test show that the brake system and the regenerative braking cooperative control algorithm satisfy the demanded braking force by performing cooperative control between regenerative braking and friction braking. The regenerative braking cooperative control algorithm can increase energy recovery of the regenerative braking by increasing the gradient of the demanded braking force against the pedal stroke. The gradient of the demanded braking force needs to be determined with consideration of the driver's braking characteristics, regenerative braking energy, and the driving comfort.