Energy Regeneration Efficiency Research Articles

An experimental investigation of an energy regeneration suspension

Energy absorbed from road bumps in traditional suspensions is dissipated as heat. An energy regeneration suspension (ERS) has the capability to capture and store this energy in batteries. It has the potential to be used in several categories of vehicles, encompassing cars, trucks, buses, and even trains. ERS technology shows significant promise in enhancing the fuel efficiency and environmental sustainability of vehicles. In this paper, the design of an ERS that converts kinetic energy into electrical energy is presented. The primary objective is to identify key design parameters that result in high magnetic intensity levels in the air gap of the ERS model. Optimizing these parameters is essential to maximize the advantages of ERS while minimizing any drawbacks. The study investigates the impact of different magnetic permeability materials in the ERS model using ANSYS software. A test rig is established based on the analysis results to assess the energy regeneration efficiency of the ERS model under various excitations. Experimental results demonstrate that ERS models with higher permeability inner sleeves exhibit superior energy regeneration efficiency.

Simulation Study on Energy Recovery and Regeneration of Hybrid Loader Arm

In response to the problem of large energy waste in the loader actuator, a hybrid loader boom arm energy recovery and regeneration system is proposed, which adopts a supercapacitor as the energy storage element. Firstly, the working principle of the hybrid loader boom arm energy recovery and regeneration system is analyzed. Secondly, the mathematical model of the components is analyzed. Finally, AMESim is used to model the system. The simulation is carried out under typical working conditions with the LiuGong ZL50C loader as the simulation object and compared with the conventional system. The simulation results show that the hybrid power system does not affect the motion characteristics of the loader boom arm system compared with the conventional system. The hybrid power system can perform energy recovery regardless of the mode of operation, and the energy recovery efficiency reaches 55.7 %. When the system enters the hybrid mode, the supercapacitor SOC fluctuates less, and the energy regeneration efficiency reaches 90 %. The hybrid power system can effectively reduce engine fuel consumption and pollutant emissions, with the system's energy-saving efficiency of 44.4 % and CO, HC, and NOx emissions reduced by 41.1 %, 47 %, and 19.8 %, respectively. The system provides a reference for the research of energy-saving technology of the loaders, effectively reducing the operating cost of the loaders.

Promoting substrates uptake and curdlan synthesis of Agrobacterium sp. by attenuating the exopolysaccharide encapsulation

During curdlan production by Agrobacterium sp., the secreted exopolysaccharide (EPS) gradually encapsulated Agrobacterium sp., accompanied by cell aggregation, resulted in inhibited substrate uptake and curdlan synthesis. To relieve the EPS encapsulation effect, the shake-flask culture medium was quantitatively supplemented with 2 % to 10 % endo-β-1,3-glucanase (BGN), while obtaining curdlan with a decreased weight-average molecular weight ranging from 18.99 × 104 Da to 3.20 × 104 Da. In a 7-L bioreactor, the 4 % BGN supplement substantially attenuated the EPS encapsulation, resulting in increased glucose consumption and curdlan yield to 66.41 g/L and 34.53 g/L after fermentation of 108 h, which improved 43 % and 67 %, respectively compared with the control. The disruption of EPS encapsulation with BGN treatment accelerated the regeneration of ATP and UTP, resulting in sufficient uridine diphosphate glucose for curdlan synthesis. The upregulation of related genes at the transcription level reveals that the respiratory metabolic intensity, the energy regeneration efficiency, and the curdlan synthetase activity were enhanced. This study presents a simple and novel strategy of relieving the effects of EPS encapsulation on the metabolism of Agrobacterium sp. for the high-yield and value-added production of curdlan, which could be potentially applied in producing other EPSs.

Hybrid drivetrain with dual energy regeneration and collaborative control of driving and lifting for construction machinery

The push for a more sustainable logistics industry has been driving heavy machinery manufacturers to develop electric construction machinery (ECM). To improve energy efficiency of ECM, we propose a multistage parallel hybrid drivetrain (MPHD) that combines a parallel hybrid lifting system (PHLS) with an electrohydraulic driving system. The proposed MPHD can recover both gravitational and braking energy through a network of hydraulic accumulators. To optimize power distribution of MPHD under various conditions, an energy management strategy with an adjustable degree of hybridization (DOH) is developed to collaboratively control lifting and driving systems. In addition, experiments and simulations are conducted to verify the feasibility and energy efficiency of MPHD. Taking a MPHD-equipped 2.5-t electric forklift as example, a co-simulation platform is built to demonstrate its performance in a designed cycle based on Chinese standard JB/T3300–2010. Compared with electric forklifts without energy recovery, the MPHD-equipped 2.5-t forklift displays an energy consumption reduction of 28%–35% and a dual energy regeneration efficiency of 73%–76%.

Synthesis, spectral characterization, and theoretical investigation of the photovoltaic properties of (E)-6-(4-(dimethylamino)phenyl)diazenyl)-2-octyl-benzoisoquinoline-1, 3-dione

This research work focuses on the synthesis, characterization through spectra (FT-IR, UV–vis, and 1H-NMR) investigations, and the use of density functional theory (DFT) along with time-dependent density functional theory (TD-DFT) to investigate the electronic, structural, reactivity, photophysical properties, and the photovoltaic properties of a novel (E)-6-(4-(dimethylamino)phenyl)diazenyl)-2-octyl-benzoisoquinoline-1,3-dione. The structure of the synthesized compound was modeled using the Gaussian09W and GaussView6.0.16 softwares employing B3LYP and 6–31 + G(d) basis set. The DFT studies was performed in order to investigate the Frontier Molecular Orbital (FMO), Natural Bond Orbital (NBO), charge distribution, Nonlinear Optics (NLO), and stability of the titled molecule. The HOMO–LUMO energy gap which corresponds to the difference between HOMO and LUMO energies of the studied compound was found to be 2.806 eV indicating stiff and smooth nature of the titled molecule. This accounts for the less stability and high chemical reactivity of the compound. The photovoltaic properties were conducted to evaluate the light harvesting efficiency (LHE), short circuit current density (JSC), Gibbs free energy of injection (Delta {G}_{inj}), open cycled voltage (VOC) and Gibbs free energy regeneration (Delta {G}_{reg}) and solar cell conversion efficiency. Interestingly, the results obtained were found to be in good agreement with other experimental and computational findings.

Numerical Analysis of Energy Recovery of Hybrid Loader Actuators Based on Parameters Optimization

The conventional loader actuator hydraulic system suffers from the potential energy waste problem of the boom arm. This study proposes a hydraulic control method and control strategy for the energy recovery and regeneration of a hybrid loader arm. When the boom arm drops, the piston side of the boom cylinder charges the accumulator, and the system achieves energy recovery. When the boom arm rises, the accumulator releases hydraulic energy to drive the energy regeneration hydraulic motor to provide energy for the system, and the system achieves energy regeneration. The system’s principle analysis and the mathematical model are completed based on Boyle’s, Newton’s second law, and the flow continuity principle. The simulation model is established using AMESim 2D mechanical library, HCD library, and signal library. Under the typical working condition, 50-type wheel loader numerical simulation research is conducted, and the system cylinder motion characteristics, accumulator charging and discharging performance, system energy recovery, and regeneration performance are obtained. On this basis, energy recovery and regeneration efficiency are selected as optimization objectives. The optimal designs of accumulator and energy regeneration hydraulic motor parameters are carried out to obtain the influence law of accumulator and hydraulic motor parameters on system energy recovery and regeneration, and the energy-saving effect of the system is analyzed. The results show that the optimized parameters effectively improve the system energy recovery and regeneration efficiency and reduce engine fuel consumption. The system provides a reference for designing an energy recovery system and researching the energy-saving technology of loaders.

ENERGY ENHANCEMENT OF ELECTRIC VEHICLES THROUGH REGENERATIVE BRAKING SYSTEM

Electric Vehicles (EVs) and Hybrid Electric Vehicles (HEVs) have been attracting a lot of attention for environmental issues and energy crisis. One of advantage of using foregoing vehicles is charging energy by regenerative brake. Regenerative braking systems (RBS) are a useful way to capture the energy lost while braking and at the same time lowering exhaust and brake emissions. The idea behind this process is to transform mechanical energy from a motor's kinetic energy into electrical energy. This paper, gives comprehensive information about regenerative energy system. Later, a case study of an electric vehicle conversion's electrical energy use in a real-world setting has been looked at. Such tests assess the energy usage of a vehicle's overall system whether it has regenerative braking or not. The absorbed capacity of regenerative energy is limited because of motor capacity and current limit of battery. This becomes serious issues the heavy weight vehicle such as bus and truck. To increase regenerative energy, large motor and battery are requested, which is difficult because of cost and limit of inverter capacity. With the advancement of energy regeneration technologies, the driving range of electric vehicles can be enhanced. Two boost approach, a unique energy regeneration strategy, is suggested in this paper for electric vehicles powered by brushless DC motors. Additionally, since this approach regenerates more energy than the single boost method, this method's energy regeneration efficiency has been greatly improved.

Transmission and energy-harvesting study for a novel active suspension with simplified 2-DOF multi-link mechanism

In this paper, a new energy-regenerative suspension system with a simplified multi-DOF mechanism was proposed. The research firstly focuses on characteristics of the transmission and conversion analysis, and energy recovery calculation. Then the relationship between the vibration amplitude and the rotation angle is computed and simulated. The dead angle of motion is found. A novel parameter K is proposed to describe the outer profile envelope of the linkages for the first time, which provides a potential reduction for the control matrix dimension. A 2-DOF suspension model, integrated with the multi-link rotating electromagnetic regenerative shock absorber, is built, simulated, and analyzed. The kernel simulation results are validated by experiments at last. Driving on Class B road, the results show that the energy-regenerative suspension controlled by the LQG algorithm is 20.56% smaller than the passive suspension in Body Acceleration; the energy regeneration efficiency is 14.28%, and the self-supply efficiency is 54.66%. Comparing to the ball-screw structure, we increase the energy harvesting ratio by 21.43% with similar control effects. The research provides new ideas for suspension design and control, reduces energy consumption, and improves ride comfort and driving stability as well.

Study on the effect of switching inertance hydraulic system on energy regeneration efficiency due to difference in valve switching time and piping configuration.

Study on the effect of switching inertance hydraulic system on energy regeneration efficiency due to difference in valve switching time and piping configuration.

A Boom Energy Regeneration System of Hybrid Hydraulic Excavator Using Energy Conversion Components

In this paper, a novel design of an energy regeneration system was proposed for recovering as well as reusing potential energy in a boom cylinder. The proposed system included a hydraulic pump/motor and an electrical motor/generator. When the boom moved down, the energy regeneration components converted the hydraulic energy to electrical energy and stored in a battery. Then, the regenerated energy was reused at subsequent cycles. In addition, an energy management strategy has been designed based on discrete time-optimal control to guarantee position tracking performance and ensure component safety during the operation. To verify the effectiveness of the proposed system, a co-simulation (using MATLAB and AMESim) was carried out. Through the simulation results, the maximum energy regeneration efficiency could achieve up to 44%. Besides, the velocity and position of the boom cylinder achieved good performance with the proposed control strategy.

Improvement of Energy Regeneration for Hydraulic Excavator Swing System

A novel energy regeneration swing system is proposed for hydraulic excavator in this paper to reduce the energy consumption. Two independent accumulators are proposed for use in the hybrid swing system. The combined control of hydraulic motor displacement and flow control valve and a variable accumulator control strategy were proposed to improve the energy regeneration efficiency and ensure the system performance. A testbench was set up, and experiments were conducted. The experiment verified that the energy regeneration efficiency of the proposed system ranged from 23 to 56% in different conditions.

Energy Regeneration and Reuse of Excavator Swing System with Hydraulic Accumulator

In order to solve the environmental pollution and the depletion of petroleum energy, construction machine with high efficiency needs to be urgently developed. In this paper we propose a new energy regenerative swing system with a hydraulic accumulator, variable hydraulic motor and proportional flow control valve for realizing highly energy efficient construction machine. Furthermore, we proposed a novel control algorithm for the reduction of vibration of upper frame of excavator as well as high energy regeneration and reuse. A test bench was fabricated, and experiments have been conducted. From the experimental results, it was verified that the mean energy regeneration efficiency and energy saving efficiency were 33.4 and 9.2% and the vibration of upper plate of excavator can be assumed to be reduced by experimental results.

Energy regeneration technique for electric vehicles driven by a brushless DC motor

The development of energy regeneration capability in electric vehicles can extend their driving range making them a competent alternative for conventional internal combustion engine vehicles. In this study, a novel energy regeneration technique, called a two-boost method, for electric vehicles driven by a brushless DC (BLDC) motor, a widely used motor in vehicular technology, is proposed. Based on this technique, the BLDC motor driver, which is selected to be a three-phase inverter, is converted into two simultaneous boost converters during energy regeneration periods in order to transfer energy from the BLDC motor into the battery and provide the braking force. Also, this method is compared with the single-boost method. The simulation and experimental results show that the amount of regenerated energy in this method is more than twice of that in the single-boost method. Moreover, it is observed that in the two-boost method, the motor speed changes linearly without any control of the electrical torque. In addition, since the amount of regenerated energy in this method as compared to the single-boost method is higher, the energy regeneration efficiency in this method is increased significantly.

Optimization of energy regeneration of hybrid hydraulic excavator boom system

Saving energy is important and necessary for hydraulic excavators. This paper proposed a novel energy regeneration boom system. A variable displacement hydraulic motor and flow control valve were used to regulate the torque and speed of the generator, and to regulate flow through the hydraulic motor. A control strategy was proposed to calculate the optimal displacement of the hydraulic motor. The hydro-mechanical efficiency map and volumetric efficiency map were used to estimate the speed and torque of the generator instead of using speed and torque sensor. The resulting energy regeneration efficiency ranged from 33.8% to 57.4%, which cannot be realized in conventional boom system. Compared with conventional energy regeneration boom system, the improvement of energy regeneration efficiency with the proposed system was 3.2% to 4.1% for low and moderate velocities. A control strategy has been proposed to decrease the setup power of generator and ensure system safety in large load and high velocity mode.

A Novel Control Strategy for an Energy Saving Hydraulic System With Near-Zero Overflowing Energy-Loss

The relief valve overflowing energy loss is considered impossible to solve. This paper proposes a new type of proportional relief valve (PRV) with a hydraulic energy regeneration unit (HERU) connected to its outlet. The mathematical model of the proposed PRV is set up, and its stability is analyzed. A control strategy is put forward for designing the working modes which are based on the pressure of the hydraulic accumulator. The simulation model and the test rig, where a hydraulic accumulator is used as a HERU, are established to verify the effectiveness of the control strategy and energy savings of the proposed PRV. The results show that the system can switch among energy regeneration, energy release, and traditional modes according to the hydraulic accumulator pressure, indicating that the proposed control strategy works well. During the energy regeneration mode, the hydraulic accumulator is charged and the PRV inlet pressure decreases only slightly, indicating the HERU has little influence on the PRV working performance. During the energy release mode, the hydraulic accumulator is discharged and the PRV inlet pressure increases to its preset value. Both during the regeneration and release modes, the driving electric motor consumed less energy. Higher hydraulic accumulator pre-charging pressure can achieve higher energy regeneration efficiency, whereas lower hydraulic accumulator pre-charging pressure can regenerate more overflowing energy.

Damping properties and energy evaluation of a regenerative shock absorber

This paper presents dynamics analysis of a regenerative shock absorber using a linkage mechanism as motion transmission developed from a valid kinematics analysis. The main objective of this study is to obtain force and energy regeneration properties, which is followed by regeneration efficiency. Physical based models are adopted from the structural design and mathematical models are derived in order to conduct numerical investigations. Parameters are determined by estimation and measurement, while sinusoidal displacement input and its derivations are used to study system behaviors. In fixed amplitude and frequency, the total damping force is explored in time, displacement and velocity response, while regenerative power is compared to mechanical power in time domain for gaining efficiency. The result shows that asymmetry occurs in force–velocity curve which is influenced by mass inertias of epicyclic gears. In different amplitudes and frequencies, the damping nature, harvested power and efficiency are studied and linked with regard to the proportion of mechanical and electrical force. The result indicates that the electrical force has much contributed in low range of amplitudes and frequency, which is followed by energy harvesting and regeneration efficiency.

Energy Regeneration Hydraulic System via a Relief Valve with Energy Regeneration Unit

Relief valves are widely used in industrial machinery. Due to the outlet of the relief valve being connected to the tank, the pressure drop of the relief valve is frequently equal to the inlet pressure. Accordingly, the energy loss of the relief valve is very high in some cases and this will worsen with an increase in the rated pressure of the hydraulic system. In order to overcome the disadvantage of overflow energy loss in a relief valve, a hydraulic energy regeneration unit (HERU) is connected to the outlet of the relief valve to decrease the pressure drop between the inlet and outlet of the relief valve. The overflow loss, which is characterized by the pressure drop, can be reduced accordingly. The approach is to convert the overflow energy loss in hydraulic form and allow for release when needed. The configuration and working principle of the relief valve with HERU is introduced in this present study. The mathematical model is established to obtain the factors influencing the stability of the relief valve. The working pressure of the hydraulic accumulator (HA) is explored. Furthermore, the control process of the operating state of the HA is scheduled to decide whether to regenerate the energy via the HERU. The software AMESim is utilized to analyze the performance and characteristics of the relief valve with HERU. Following this, the test rig is built and used to verify the effectiveness of the proposed relief valve with HERU. The experimental results show that the relief valve with the HERU connected to its outlet can still achieve better pressure-regulating characteristics. The energy regeneration efficiency saved by the HA is up to 83.6%, with a higher pre-charge pressure of the HA. This indicates that the proposed structure of the relief valve with HERU can achieve a better performance and higher regeneration efficiency.

Braking force control strategy for electric vehicles with load variation and wheel slip considerations

The braking system plays an important role in electric vehicles. In order to achieve high energy regeneration efficiency and also ensure driving safety at the same time, the regenerative braking system should be well coordinated with the mechanical braking system. As the brake-by-wire technology is developed, individual control of braking force on each wheel can be realised, which is suitable for the future electrified vehicles. This paper aims to investigate the braking force control strategy for electric vehicles under a low road friction condition. In order to further improve the braking force control accuracy and eliminate the effect of the vehicle load variation, a vehicle load estimation method is proposed. The standard hybrid braking force control strategy of electric vehicle is introduced for comparison with the proposed control strategy. To prevent a front wheel lock-up and maximise the regenerative braking efficiency under a low tyre-road friction condition, a revised control strategy is presented with the front wheel slip ratio consideration. Simulation results indicate that by using the proposed strategy, the vehicle braking performance under the low tyre-road friction condition is guaranteed and the regenerative braking force on front axle is fully utilised compared with the standard control strategy.

616 インテリジェント短下肢装具におけるエネルギー回生効率の数値シミュレーション(機械力学・計測制御VI)

616 インテリジェント短下肢装具におけるエネルギー回生効率の数値シミュレーション(機械力学・計測制御VI)

Shape Effect of Piezoelectric Energy Harvester on Vibration Power Generation

Vibration energy harvesting is widely recognized as the useful technology for saving energy. The piezoelectric energy harvesting device is one of energy harvester and is used to operate certain types of MEMS devices. Various factors influence the energy regeneration efficiency of the lead zirconate titanate piezoelectric (PZT) devices in converting the mechanical vibration energy to the electrical energy. This paper presents the analytical and experimental evaluation of energy regeneration efficiency of PZT devices through impedance matching method and drop-weight experiments to different shape of PZT devices. The results show that the impedance matching method has increased the energy regeneration efficiency while triangular shape of PZT device produce a stable efficiency in the energy regeneration. Besides that, it becomes clear that the power, energy and subsequently efficiency of the triangular plate are higher than those of the rectangular plate under the condition of the matching impedance and the same PZT area.