A Novel Hybrid Control Strategy for Maximising Regenerative Braking Capability In a Battery-Supercapacitor Energy Storage System (original) (raw)
Related papers
2018
EVO Electric has designed, built and tested the DuoDrive hybrid system based on proprietary axial flux motor technology, and installed it in a London Taxi Cab. The DuoDrive switchable series/parallel hybrid system has demonstrated a 60% improvement in fuel economy compared to a conventional taxi when operated over an urban drive cycle. As with many hybrid vehicles, a large part of this improvement is attributed to effective and efficient recapture of braking energy. The amount of braking energy that can be recovered, and the efficiency with which it can be returned to the road will therefore have a significant impact on the overall fuel economy of the vehicle. One factor that limits the amount of energy that can be recovered is the allowable charge rate of the battery, as braking events are usually high power and in a hybrid vehicle the battery size is generally small. The vehicle described in this paper has an energy storage system comprised of high power ultra-capacitors and a hig...
A Development of an Energy Storage System for Hybrid Electric Vehicles Using Supercapacitor
An energy storage system for improving performance of hybrid electric vehicles (HEV) is presented. The hybrid power system consists of batteries and supercapacitors. The supercapacitor contributes to the rapid energy recovery associated with regenerative braking and to the rapid energy consumption associated with acceleration in electric vehicles. This power system allows the acceleration and deceleration of the vehicle with minimal loss of energy and minimizes the stress of the main batteries by reducing high power demands away from the batteries. It also leads to longer battery life by extracting energy at a slower average rate. The total weight of hybrid system is lighter than that applied only batteries, so that the efficiency of vehicle is increased. In this paper, the equivalent model of supercapacitor is included. This model can be used in simulating for automotive power systems, e.g. the voltage response and energy efficiency. The soft switching bidirectional DC-DC converter is used to connect the supercapacitor with the battery for the controlled instantaneous electric power flow. The hybrid power system is analyzed and verified by experimental results from the prototype system.
Designing & Analysis of Supercapacitor Hybrid Battery System with Regenerative Braking
IJRASET, 2021
This work implements the help of a super capacitor hybridized with a battery pack to power a motor to work an electric bike. The supercapacitor of specification is built in combination with the battery pack to work in pair at instances where more load in needed. For example in situations like accelerating, decelerating, and climbing a slope. The supercapacitor is recharged while in motion using two different technologies: 1. Regenerative Braking and 2. Generator incorporated into wheel hub. Regenerative braking is an energy recovery mechanism that slows down a moving vehicle or object by converting its kinetic energy into a form that can be either used immediately or stored until needed. In this mechanism, the electric traction motor uses the vehicle's momentum to recover energy that would otherwise be lost to the brake discs as heat. This contrasts with conventional braking systems, where the excess kinetic energy is converted to unwanted and wasted heat due to friction in the brakes, or with dynamic brakes, where the energy is recovered by using electric motors as generators but is immediately dissipated as heat in resistors. In addition to improving the overall efficiency of the vehicle, regeneration can significantly extend the life of the braking system as the mechanical parts will not wear out very quickly. The system uses Faradays Law of Electromagnetic Induction to induce an EMF and generate voltage by passing a current carrying conductor through a rotating magnetic field. Using this implementation, it has been noted that the battery life has been increased significantly and the total range of the bike has also increased considerably.
—In this paper, a new battery/ultracapacitor hybrid energy storage system (HESS) is proposed for electric drive vehicles including electric, hybrid electric, and plug-in hybrid electric vehicles. Compared to the conventional HESS design, which uses a larger dc/dc converter to interface between the ultracapacitor and the battery/dc link to satisfy the real-time peak power demands, the proposed design uses a much smaller dc/dc converter working as a controlled energy pump to maintain the voltage of the ultracapacitor at a value higher than the battery voltage for the most city driving conditions. The battery will only provide power directly when the ultracapacitor voltage drops below the battery voltage. Therefore, a relatively constant load profile is created for the battery. In addition, the battery is not used to directly harvest energy from the regenerative braking; thus, the battery is isolated from frequent charges, which will increase the life of the battery. Simulation and experimental results are presented to verify the proposed system.
Today's battery powered electric vehicles still face many issues: (1) Ways of improving the regenerative braking energy; (2) how to maximally extend the driving-range of electric vehicles (EVs) and prolong the service life of batteries; (3) how to satisfy the energy requirements of the EVs both in steady and dynamic state. The electrochemical double-layer capacitors, also called ultra-capacitors (UCs), have the merits of high energy density and instantaneous power output capability, and are usually combined with power battery packs to form a hybrid power supply system (HPSS). The power circuit topology of the HPSS has been illustrated in this paper. In the proposed HPSS, all the UCs are in series, which may cause an imbalanced voltage distribution of each unit, moreover, the energy allocation between the batteries and UCs should also be considered. An energy-management scheme to solve this problem has been presented. Moreover, due to the parameter variations caused by temperature changes and produced errors, the modelling procedure of the HPSS becomes very difficult, so an H∞ current controller is presented. The proposed hybrid power source circuit is implemented on a laboratory hardware setup using a digital signal processor (DSP). Simulation and experimental results have been put forward to demonstrate the feasibility and validity of the approach.
Energy Conversion and Management
This paper presents the comparative study of two hybrid energy storage systems (HESS) of a two front wheel driven electric vehicle. The primary energy source of the HESS is a Li-Ion battery, whereas the secondary energy source is either an ultracapacitor (UC) or a flywheel energy system (FES). The main role of the secondary source is to deliver/recover energy during high peak power demand, but also to increase battery lifetime, considered among the most expensive items in the electric vehicle. As a first step, a techno-economic comparative study, supported by strong literature research, is performed between the UC and the FES. The design and sizing of each element will be presented. The comparison criteria and specifications are also described. The adopted approach in this paper is based on an academic non-oriented point of view. In a second step, each of the HESS will be integrated in a more global Simulink model which includes the vehicle model, the traction control system (TCS), the regenerative braking system and the vehicle actuators. Simulation tests are performed for an extreme braking and vehicle starting-up operations. Tests are realized on two different surface road types and conditions (high and low friction roads) and for different initial system states. In order to show the most appropriate storage system regarding compactness, weight and battery constraints minimization, deep comparative analysis is provided.
IEEE Transactions on Transportation Electrification, 2017
Using multi-input converters (MICs) in hybrid energy storage systems (HESSs) presents several advantages, such as, low component count, control simplicity and fully control of source energies. The power levels of sources in these systems need to be determined wisely by an energy management strategy (EMS). This paper presents an EMS for a battery/ultra-capacitor (UC) HESS including a bidirectional MIC for electric vehicles (EVs). Thanks to the fact that energy flow between battery and UC is free in this MIC, the proposed EMS not only regulates the state-of-charge of UC but also smooths the battery power profile by using a fuzzy logic controller and a rate-limiter. Therefore, it results in a sustainable HESS with longer battery life. Through a simulation study and an experimental setup including a real EV, the performance of the proposed system is evaluated comprehensively. Then, based on experimental results, battery cycle life improvement due to the battery/UC hybridization is explored.
IJIREEICE, 2017
With the emerging technologies in the field of Energy Storage System Development, the interest for the development of Electric Vehicle (EV's) is growing for future road transportation.In this paper the Battery plus Ultracapacitor (UC) Hybrid Energy Storage System(HESS)with an energy management control strategy is proposed. The proposed control strategy optimizes the energy consumption, improves vehicle performance and prolongs the battery lifetime for different vehicle Drive cycles.The proposed HESS topology incorporates the bidirectional DC-DC converter and a complimentary switch pair for interconnection of energy sources and interconnection with vehicle traction drive. The proposed HESS interconnected with BLDC motor and the control strategy is implemented for the acceleration and braking conditions of the vehicle. The DC-DC converter is of small size and itis used for sharing the energy between Battery and Ultracapacitor. It also balances the energy levels of the two sources based on the vehicle drive cycles. And the complimentary switch pair swaps the vehicle load between the two sources based on the vehicle driving condition for optimum energy consumption. The Ultracapacitor contributes to the rapid energy recovery associated with regenerative braking and rapid energy consumption associated with vehicle acceleration. This power system allows the acceleration and deceleration of the vehicle with minimal loss of energy and minimizes the stress on the main batteries by reducing high power demands away from the batteries.The objective of the control strategy developed is to provide uninterrupted and adequate power from HESS to the vehicle motor drive unit for all drive cycles of vehicle. The control logic considers the Battery Voltage, Ultracapacitor Voltage and vehicle speed in order to provide a smooth control, reliable and efficient energy sharing between HESS and vehicle motor drive unit. The Battery SOC and open circuit voltage(OCV) are important parameters for ascertaining battery life because fully charged batteries do not accept any current and hence, under this condition, the Ultracapacitor should be available discharged (that means no more than 15-20 % of its full capacity) to store the energy generated due to regenerative braking at high speeds. By contrast, if the battery state of charge is poor, the ultracapacitor should be available fully charged (that means more than 90 %of its full capacity) to power the traction motor for sudden acceleration.To achieve this requirement both the sources are interconnected through a bidirectional DC-DC Converter which is controlled by the speed of the vehicle.And thus the UC voltage is maintained at required level based on the vehicle speed by sharing the energy between Battery and UC for different drive cycles of the vehicle.
Hybrid battery-supercapacitor storage system for electric city cars
The paper is concerned with the use of hybrid battery-supercapacitor storage systems to extend the range of electric vehicles. For the study case of an electric city car, the paper calculates the relationship between the range of the city car over the ECE 15 cycle and the size of the supercapacitor bank. For this purpose, current drawn by the traction system is determined and the current pulses are supposed to be delivered by the supercapacitor bank to different extents. The range is then calculated by processing the battery current by means of an appropriate battery model.