Regenerative Mode Research Articles

Speed Estimation Technique Using Modified Stator Current Error-Based MRAS for Direct Torque Controlled Induction Motor Drives

This paper uses a stator current error-based model reference adaptive system (MRAS) to estimate the speed of an induction motor drive. Usually, speed error signal uses the cross product of stator current error vector and flux linkage vector for the estimation of speed. However, this speed error signal has limitations, such as speed tracking error and instability (at regenerative mode) under loaded conditions at low speeds. To mitigate these issues, a modified MRAS speed estimation algorithm is proposed in this paper. In the proposed method, the adaptive model state variables are formulated in terms of flux linkages (stator and rotor) in order to alleviate the impact of current noise in the flux linkage estimation. Moreover, a compensator is added to reduce the speed error tracking in the reference model. Furthermore, the stability of the drive is kept by using the dot product of stator current error vector and the rotor flux linkage vector during the regenerative mode of operation. The analysis of the proposed algorithm is presented and validated experimentally on the laboratory setup with direct torque control-space vector modulation technique for a wide operating range including the dynamic performance.

Integrated onboard single‐stage battery charger for PEVs incorporating asymmetrical six‐phase induction machine

This study proposes an integrated battery charger for plug-in electric vehicles (PEVs) that involves an asymmetrical six-phase induction motor as propulsion drive. Proposed power electronic interface (PEI) uses a CuK-based bidirectional DC/DC converter, which is capable of performing buck/boost function during all modes of operation. It operates as a power factor correction converter during plug-in charging mode, and a single switch inverting buck/boost converter in propulsion and regenerative braking modes. Selection of a wide range of battery voltages and adequate control over regenerative braking can be achieved with the proposed multi-functional converter. In addition, size, weight and cost of the charger are also reduced, as it involves a minimum number of components compared to existing buck/boost converters used in chargers. By utilising a six-phase induction machine drive in the propulsion system, efficiency and power density of the PEI is improved. This drive even allows for further modifications to the proposed topology. An efficient indirect field-oriented control for the six-phase machine is also demonstrated in the study. The proposed PEI is highly suitable for onboard charger and propulsion system of PEVs. A laboratory prototype of the aforementioned converter and propulsion drive has been built to validate all modes of vehicle operation.

Совершенствование силовой цепи электровоза переменного тока в режиме рекуперативного торможения

The article presents a standard electric power circuit of an AC locomotive of Ermak series operating in the mode of regenerative braking and reveals the circuit’s drawbacks. To eliminate them, it is proposed to use an improved power circuit where standard reversible converter is replaced with a more advanced IGBT-based counterpart and exclude ballast resistor blocks from the armature circuits of traction motors. A mathematical modeling of a standard system of AC locomotive regenerative braking is performed. The conducted mathematical modeling allowed to obtain the curves of the catenary current and voltage, generator current, inverter voltage and power factor. A method of regenerative braking without the application of ballast resistor blocks is proposed. Having analyzed the electromagnetic processes of AC locomotive standard power circuit operation in the regenerative braking mode, the authors have revealed a number of drawbacks that have an adverse effect on the efficiency of regenerative braking. A technical solution for improving the AC locomotive power circuit is introduced that enables a substantial increase of the locomotive energy performance in this operation mode.

Fryze reactive power of trams in effective stochastic recuperation processes

Urban electric transport system, particularly tram systems, is not a direct current system not only in traction mode but in regenerative modes as both voltage on a collector and regenerative current are stochastic abruptly variable processes. The above- mentioned facts determine availability of Fryze’s reactive power in this system that flows from a railway substation to trams, leads to incidental losses of energy and significantly reduces its quality. So evaluation of power effectiveness of the system in electrical trams operation is impossible without determining the level of reactive power in this system. We have analytical expression of reactive power by Fryze. Numerical calculations for trams type T3D and T4D in regenerative braking modes are done. Probabilistic statistical data processing operation of reactive power expressions is done. It is determined that reactive power changes in the limit of 10…100 kilo-volt ampere reactive with mathematical expectation – 37,0 kilo-volt ampere reactive. Statistical allocation of random power values are different. Numerical calculations of incidental losses, energy of recuperation are done and they range supplementary – 20% from total losses. It is stated that coefficient of reactive power of system route of trams is exceeding permissible value 0,25.

Experimental investigation of actual situation of using and accounting of recovered energy of regenerative braking mode at the DC traction system

This paper deals with the problems of enhancement of registration and distribution of electric energy which can be obtained from DC electric locomotives by the regenerative braking. According to theoretical researches, it is possible to return approximately 8 - 12% of electric energy which is consumed for electric traction by using of a regenerative braking mode. However in recent years for electric traction networks of JSC “Ukrainian Railways”, this index doesn’t exceed 2.6%. So we consider that the regenerative braking is one of the most prospective ways for energy saving in electric railway transport. Results of the experimental researches which were executed on DC traction substations and VL11M6 electric locomotives are described in this paper. Instantaneous values of voltage and current in different modes have been obtained. The electric energy balance for experimental zone has been performed. Also the ways of distribution and consumption of energy of regenerative braking mode have been analyzed. On this basis of the executed investigations, recommendations about providing of supercapacitor energy storage system for Ukrainian railways are proposed.

Энергосберегающий электропривод для стенда испытаний тракторных шин

The article addresses matters concerned with designing the tractor tire test bench with taking into account the shortcomings of its previous designs and considers the possibility of performing tractor tire tests with better energy efficiency and reliability. The existing domestic and foreign test benches are analyzed. The test bench electric drive power part’s functional diagram is proposed along with the power flows and power loss distribution diagram in the bench drives for estimating their power performance characteristics. From the technical point of view, the aim of the development is to reduce the electricity consumption. To this end, the bench is equipped with two additional electric machines operating in regenerative braking modes, thereby ensuring return of energy back to the network (an individual loading induction motor is provided for each tire). The article describes the bench design, its technical characteristics, requirements for the bench control system, and the technical solution that allows more efficient tire test results to be obtained due to returning energy back to the network and due to the fact that the drive power is now spent only to compensate losses in the bench mechanisms. A vector control system of interconnected electric drives used in the bench is mathematically modeled, and its technical capabilities are investigated. The effectiveness of the proposed solution is proved based on estimating the energy return level to the drive power supply grid.

Selection of parameters of a three-flow parallel electromechanical transmission of a tracked vehicle

One of the serious shortcomings of electromechanical transmissions, restraining their widespread use on tracked vehicles, is the large weight of electric motors and energy storage devices. The article provides a three-flow transmission scheme with the minimum number of electric machines necessary to ensure stepless acceleration and rotation with the obligatory use of an internal combustion engine and electric drive. Reducing the number of electric machines is achieved by using the same machines as traction motors and generators, depending on the mode of operation. This implies that when driving at speeds below average, electric machines should work as a generator, above average - as a traction motor. Transmission allows movement without the use of electric machines, but with reduced performance. The article discusses five modes of transmission, the specific traction and power characteristics for these modes. The features of the use of short-term and long-term characteristics of electric machines in the engine mode are taken into account. The use of the internal combustion engine is substantiated not only in the nominal mode, but also in the maximum power mode. A method for selecting transmission ratios, characteristics of the internal combustion engine and electric machines is presented and justified. The calculation is made for the track conveyor of the ultra-light mass category. A description of the regenerative braking modes available for transmission, as well as a description of the mode of charging the drive when parked are given. The scientific problems of evaluating the efficiency of the transmission, the need to study the rotation of the tracked vehicle where it is installed, the development of top-level algorithms for its control are indicated.

Regenerative Braking Mode Operation of a Three-Phase H-Bridge Inverter Fed PMBLDC Motor Generator Drive in an Electric Bike

In this article, the industrial application of three-phase H-bridge inverter fed PMBLDC drive system with its regenerative braking and motoring modes of operation produce electric energy harvestation and its effective utilization in an electric bike is discussed. The H-bridge inverter topology having two legs with four gate drive switches, reduce current ripples and improves the current rating of a drive system. Therefore, the three-phase H-bridge inverter connected PMBLDC drive can be preferred for high torque applications with reduced torque ripples during the commutation of switches. The PMBLDC drive is a permanent magnet machine; so it is proposed in both motoring and regenerative braking modes of operation. In motoring mode, drive consumes electrical energy from battery source for converting the electrical energy into suitable mechanical energy for riding the electric bike. But in a regenerative braking mode, drive produces electricity for charging the battery source from a mechanical loading of an electric bike. The regenerative braking mode of operation improves the overall efficiency of the drive system. The performance of a three-phase H-bridge inverter fed PMBLDC drive with these modes are analyzed using MATLAB/Simulink software, the hardware circuit is implemented with supporting simulations in the Proteus 8.0 software and finally the electric bike is designed using 2 hp PMBLDC drive system.

Preferred learning styles of Thai learners in anti-aging and regenerative sciences

Background: Several studies reported that every individual learner has its own different style of learning. All learners have their own preferences for the ways in which they receive information for studying.Aims and Objective: In order to determine whether a particular teaching method provided by each instructor might enhance learner of anti-aging and regenerative medicine satisfaction with the learning process, a well-known learning preferences survey which are linked to sensory modalities of learners was distributed to anti-aging and regenerative science students at School of Anti-Aging and Regenerative Medicine, Mae Fah Luang University, Bangkok, Thailand.Materials and Methods: The applied preferred learning style survey named VARK was applied to identify student’s preferences for particular learning modes of information presentation. This study thus aimed to determine the preferred learning style and measure the distribution of learning preference mean scores of the anti-aging and regenerative science learners using 53 participants. The VARK questionnaire divided all learners into five groups, i.e., visual, aural, read/write, kinesthetic, and multimodal learners, respectively.Results: We found that the unimodality preference was 35.10% while the multimodality was 64.9%. Among the learners who preferred only one mode of information presentation, there were 8.25% of visual, 34.26% of aural, 22.44 % of read/write learners, and 35.05% of kinesthetic, respectively. Anti-aging and regenerative science learners preferred kinesthetic learning at a higher percentage than other modes. However, some learners preferred multiple modes including 32.45% of bimodal, 23.84% of trimodal, and 8.61% of quadmodal, respectively. Knowing the anti-aging and regenerative science learners preferred learning modes can help to provide instruction tailored to the learner’s individual preferences, to overcome the predisposition to treat all anti-aging and regenerative science learners in a similar way, to motivate instructors to move from their preferred mode(s) to using others, and to develop appropriate learning approaches.Conclusion: The result of this study would explore opportunities for anti-aging and regenerative science instructors to make the educational experience more productive.Asian Journal of Medical Sciences Vol.9(6) 2018 14-19

An HSC/battery energy storage system‐based regenerative braking system control mechanism for battery electric vehicles

This paper proposes a novel hybrid energy storage system (HESS) for the regenerative braking system (RBS) of the front‐wheel induction motor‐driven battery electric vehicle. The HESS is an amalgamation of multiple hybrid supercapacitors (HSCs) and lithium‐ion battery cells. An artificial neural network (ANN)‐based RBS control mechanism was used to optimize the switching scheme of the RBS's three‐phase inverter and the vehicular breaking force distribution. In the regenerative braking mode, the ANN‐based HSC/battery RBS transferred the braking energy to be stored in the HSC and, upon reaching the HSC's maximum safety threshold, then to the battery. In addition, the RBS control mechanism could achieve uniform braking force distribution between the front and rear wheels of the vehicle. Furthermore, our findings revealed that the experimental HSC/battery RBS program enhanced the harvesting of the regenerative braking energy, as was evident from the longer driving distance vis‐à‐vis that of the battery‐only vehicle. The HSC/battery RBS also contributed to improved vehicle acceleration and an extended battery life. © 2018 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

Sensorless passivity based control for induction motor via an adaptive observer

The work of this paper addresses the study and application of control strategies based on the passivity of a sensorless induction motor (IM) in order to guarantee a high performance operation and to increase reliability at a lower cost. This control approach based on the passivity or the energy formulation is generally simple and physically meaningful. It achieves the control objective by reshaping the system natural energy and then injecting a damping term. A full-order adaptive observer is also considered to estimate the IM rotor flux and mechanical speed. These estimated quantities are then used in the control scheme. The observer gain is synthesized in the way that it minimizes the instability zone in the regenerative mode to a line in the torque–speed plane. The control-observer set is tested on the trajectories of the various operating modes (motor mode, regenerating mode and low speed mode).

A Review on Chatter in Robotic Machining Process Regarding Both Regenerative and Mode Coupling Mechanism

During the last few decades, industrial robots have been widely used in various applications to develop a flexible and efficient manufacturing process such as material handling and welding. However, as a high value-added application, few robotic machining systems have been installed mainly due to the limitation from the chatter, which leads to the poor product quality and low productivity. Although researchers have been continuously investigating the robotic machining chatter, there is still a lack of understanding due to the complexity of the issue. This paper provides a comprehensive review on chatter-related issues during robotic machining tasks, including mechanisms, mitigation strategies, and identification methods regarding both regenerative chatter and mode coupling chatter. Due to the low stiffness and couple structure of industrial robots, both regenerate and mode coupling chatter can occur at different cutting conditions. The difference between two chatter mechanism in the robotic machining process are compared and a list of guidelines is provided to help in distinguishing these two types of chatter. Systemic analysis of the mechanisms of the chatter identification and suppression is presented providing a research basis for future studies.

The Energy Efficiency of an Automatic Control System of Subway Train Movement and Requirements for Its Subsystems

A review has been carried out of methods for increasing the energy efficiency of automatic control over the movement of subway trains: choosing an energy optimal sequence of train control modes, distributing the travel time along the line for travel times over the sections between stations, and using the regenerative braking mode. The results of a study related to the influence of the automatic control system on the energy consumption for traction by train are presented. An analysis of the effect of the increase in the time of impact braking in conditions of different types of sections between stations on additional energy consumption at a given train travel time over the section between stations both in the absence and in the presence of a regenerative brake was carried out. The requirements for the path correction sensors, which should provide the necessary accuracy of the train positioning during intense braking, are formulated. A comparison of corrective sensors based on infrared signals and RFID sensors is made. The effect of changing the travel time on the section between stations in order to compensate for the discrepancy between the planned and executed traffic graphs for additional energy consumption was analyzed. In conditions of intense traffic, the requirements for the permissible error in the execution of a given train travel time over the range are ±2.5 s.

Single‐stage ZETA‐SEPIC‐based multifunctional integrated converter for plug‐in electric vehicles

A single-stage-based integrated power electronic converter has been proposed for plug-in electric vehicles (PEVs). The proposed converter achieves all modes of vehicle operation, i.e. plug-in charging, propulsion and regenerative braking modes with wide voltage conversion ratio ( M ) [ M <; 1 as well as M > 1] in each mode. Therefore, a wide variation of battery voltage can be charged from the universal input voltage (90-260 V) and allowing more flexible control for capturing regenerative braking energy and dc-link voltage. The proposed converter has least components compared to those existing converters which have stepping up and stepping down capability in all modes. Moreover, a single switch operates in pulse width modulation in each mode of converter operation hence control system design becomes simpler and easy to implement. To correctly select the power stage switches, a loss analysis of the proposed converter has been investigated in ac/dc and dc/dc stages. Both simulation and experimental results are presented to validate the operation of the converter.

Milling stability prediction with simultaneously considering the multiple factors coupling effects—regenerative effect, mode coupling, and process damping

Chatter is a kind of self-excited vibrations which is related to regenerative effect, mode coupling effect, and process damping, etc. To predict milling chatter more accurately, a suitable dynamical model of milling process which can reflect the practical chatter mechanism should be obtained firstly. In this paper, a new milling dynamical model which simultaneously considers the regenerative effect, mode coupling effect, and process damping is established. Based on the new dynamical model and the updated full-discretization method (FDM), the coupling influences of regenerative effect, mode coupling effect, and process damping on the accurate of the stability lobe diagrams (SLDs) for up-milling and down-milling operations are investigated. A series of numerical simulation and experiments are carried out to verify the accuracy of the proposed milling dynamical model. The experiment results show that the mode coupling effect and process damping have great influences on the prediction of milling stability. The SLD which obtained by the new milling dynamical equation (considering the regenerative effect, mode coupling, and process damping) is more accurate than that which obtained by only considering the regenerative effect.

Speed/Torque Estimation and Control of a DC Machine in Four Quadrants Operation Modes

Transfer function characteristics of a DC machine are used in this paper to estimate speed and torque in four quadrant operation modes. Estimation speed and torque control based on a DC machine transfer function is implemented by measuring the DC chopper instantaneous average output voltage and current. MATLAB\SIMULINK is used to implement the DC drive circuit in the forward and reverse motoring and regenerative modes, respectively. The DC drive system is simulated at different speed and load torque values in steady state and dynamic operating conditions. Simulation results demonstrate success of the sensorless and PI controller systems, which gives satisfactory agreements between the estimated, actual and reference speed and torque values.

A Multi-Functional Single-Stage Power Electronic Interface for Plug-In Electric Vehicles Application

This paper proposes a Zeta-derived non-isolated single-stage power electronic interface for on-board application of plug-in electric vehicles, which provides all modes (plug-in charging, propulsion, and regenerative braking) of vehicle operation. In addition, the proposed converter can charge the battery through universal input voltage range, i.e., 90–260 V due to buck/boost operations in plug-in charging mode. In propulsion and regenerative braking modes, the proposed converter operates as conventional boost and buck DC/DC converter, respectively. Compared to existing single-stage converters, the proposed converter has least components to those converters which have buck/boost operation in plug-in charging mode. A voltage/current stresses and loss analysis of the converter have been investigated for each mode of converter operation. Detailed simulation and experimental results are given to show the effectiveness of the proposed converter.

Investigation of a Novel Coaxial Power-Split Hybrid Powertrain for Mining Trucks

Due to the different working conditions and specification requirements of mining trucks when compared to commercial passenger vehicles, better fuel efficiency of mining trucks could lead to more significant economic benefits. Therefore, investigating a hybrid transmission system becomes essential. A coaxial power-split hybrid powertrain system for mining trucks is presented in this paper. The system is characterized as comprising an engine, a generator (MG1), a motor (MC2), two sets of planetary gears, and a clutch (CL1). There are six primary operation modes for the hybrid system including the electric motor mode, the engine mode, the hybrid electric mode, the hybrid and assist mode, the regenerative mode, and the stationary charging mode. The mathematical model of the coaxial power-split hybrid system is established according to the requirements of vehicle dynamic performance and fuel economy performance in a given driving cycle. A hybrid vehicle model based on a rule-based control strategy is established to evaluate the fuel economy. Compared with the Toyota Hybrid System (THS) and the conventional mechanical vehicle system using a diesel engine, the simulation results based on an enterprise project indicate that the proposed hybrid system can enhance the vehicle’s fuel economy by 8.21% and 22.45%, respectively, during the given mining driving cycle. The simulation results can be used as a reference to study the feasibility of the proposed coaxial hybrid system whose full potential needs to be further investigated by adopting non-causal control strategies.

Single‐phase bidirectional ac/dc converter for plug‐in electric vehicles with reduced conduction losses

Here, a non-isolated-based single-stage integrated bidirectional converter has been proposed for plug-in electric vehicles, which has the capability to achieve all modes of vehicle operation, i.e. plug-in charging, propulsion, and regenerative braking. This integrated converter has improved efficiency of 2-2.5% in propulsion boost and regenerative braking buck modes over existing non-isolated integrated converters which leads to a long run of vehicle and saves the electricity usages. Despite the proposed converter has two inductors, the size of the second inductor is approximately reduced by 35-40% compared with single-inductor converters. A detailed loss analysis of the proposed converter is investigated in propulsion boost and regenerative buck modes. Further, the design considerations of passive components are presented to achieve continuous conduction operation in each mode as well as low capacitor voltage ripple. Experimental results confirm the effectiveness of the proposed converter.

Research on Performance Test Characteristics of Solar Energy ORC Generator Set

In order to study the performance of low-temperature solar-powered ORC generator sets, a solar-powered ORC power generation test bench was designed and built. In the experiment, R-123 was used as the organic Rankine cycle working fluid, and the solar ORC power generation system was experimentally studied. The research results show that when the direct solar radiation intensity is about 400W, the temperature of the heat transfer oil at the outlet of the collector can reach 140 °C. When the temperature of the heat transfer oil at the outlet of the collector is around 110°C, the collector efficiency of the collector can reach about 60%. Under the heat source condition, when the power cycle part is switched from the basic cycle to the regenerative cycle mode, the collector heat collection efficiency can reach about 60%. Under the heat source condition, when the power cycle part is switched from the basic cycle mode to the regenerative cycle mode, the measured efficiency is increased from 9.3% to 10.8%, and the measured cycle efficiency is increased from 1.57% to 1.67%, which is an increase of 6.07%. The measured cycle system efficiency is about 10%, and the heat recovery mode is slightly higher than the basic cycle mode. The organic Rankine cycle performance under different working fluid flows was also investigated in the experiment. The maximum measured average power was 386.27 W when the working fluid flow was 6.88 kg·s. At a certain heat source temperature, as the flow rate of the working fluid increases, the inlet pressure of the expander increases, and the circulating output work also increases. Under a certain working fluid flow rate, as the temperature of the heat source increases, the temperature of the inlet of the expander increases, and the inlet pressure increases. the cycle output work also increased.