Electric Parking Research Articles

Stochastic optimization of a hybrid photovoltaic/fuel cell/parking lot system incorporating cloud model

The interaction and optimization of electric parking lots (EPLs) with hybrid renewable energy to exchange power and improve the system load reliability has been welcomed systems in energy industry, but it is accompanied by challenges such as uncertain parameters, and also implementing the optimal energy management. This paper proposes a novel stochastic optimization framework for a hybrid energy system including photovoltaic resources, hydrogen storage based-fuel cell integrated with an EPL (PV/FC/EPL) aiming for minimization of the total net present cost (TNPC) while ensuring the maximum probability of power shortage (PPSHmax) to meet a commercial load in Tianjin, China using the real meteorological data. A new improved kepler optimization algorithm (IKOA) utilizing the golden sine strategy is applied to optimize system component sizes and EPL charge/discharge. In a deterministic scenario, the optimal system configuration ensures cost-efficiency and reliability for load supply. Also, a new stochastic modeling framework is proposed using the Cloud Model (CM) to evaluate the effect of uncertainties in irradiance, temperature, and system demand on TNPC and PPSH. Deterministic findings reveal enhanced reliability and reduced TNPC through FC and EPL overlap during power shortages, compared to systems lacking EPL. Specifically, TNPC and PPSH are $8,632,643 and 1.45 %, respectively, for PPSHmax = 2 % over 20 years of operation. However, stochastic optimization demonstrates a 10.82 % increase in TNPC and an 8.67 % decrease in PPSH compared to the deterministic model under PPSHmax = 2 %, indicating heightened cost and reduced reliability when uncertainties are considered. This underscores the efficacy of the cloud model-based stochastic approach in addressing uncertainty in hybrid system optimization. Also, it reveals fluctuations in optimal cost and reliability values with changes in cloud droplet distribution around the expected value, emphasizing the significance of stochastic modeling for robust decision-making in hybrid energy systems. Moreover, evaluating the incorporating the penalty for the system's inability to supply the load, changing the storage investment cost, and interest rate variations on the system optimization cleared considerable effect of the system cost and reliability.

An improved meta-heuristic method for optimal optimization of electric parking lots in distribution network

In this study, a stochastic multi-objective structure for optimization of the intelligent electric parking lots (EPLs) is implemented in the distribution network for minimizing the power losses annual costs, power purchased from the main grid, unsupplied energy of subscribers, cost of vehicles to the grid as well as minimizing the network voltage deviations considering battery degradation cost (BDC) and network load uncertainty (NLUn). In this research, the unscented transformation method (UTM) is used for NLUn modeling and this method is easily applicable and has a low computational cost. An improved meta-heuristic algorithm named improved fire hawks optimization (IFHO) is utilized for decision variables finding defined as the site and size of the EPLs in the distribution network. The conventional fire hawks optimization (FHO) algorithm is inspired by the fire hawks foraging behavior and in this research, the Taylor-based neighborhood technique (TBNT) is used to reduce the dependency and the possibility of becoming trapped in local optimal. To evaluate the proposed methodology, the simulations are implemented in three scenarios (1) EPLs optimization without BDC and NLUn based-UTM, (2) EPLs optimization with BDC and without NLUn, and (3) EPLs optimization with BDC and NLUn. The results of the third scenario considering BDC and NLUn showed that the EPLs optimization integrated with a multi-objective framework by finding the EPL's optimal size and capacity in the network via the IFHO has reduced the annual losses, voltage deviations, ENS cost, and substation cost by 21.06%, 12.15%, 70.82%, and 39.10%, respectively compared to the base distribution network. Additionally, the results demonstrated that incorporating the BDC and NLUn, the annual losses, voltage oscillations, ENS cost, grid cost, and EPLs have increased in comparison with the EPLs optimization without BDC and NLUn based-UTM. In addition, the TBNT based-IFHO superiority has been confirmed in different scenarios by achieving better values of the objectives and also obtaining the convergence process with lower convergence tolerance and higher convergence accuracy.

Modeling and Clamping Force Tracking Control of an Integrated Electric Parking Brake System Using Sliding-Mode-Based Observer

This article proposes a hierarchical control strategy to address semi-ABS control as well as the precise clamping force control problems for an integrated electric parking brake (iEPB) system. To this end, a detailed system model, including modeling of the motor, transmission mechanism, friction and braking torque, is constructed for controller and observer design, and a sliding-mode-based observer (SMO) is proposed to estimate the load torque by using the motor rotational speed without installing a force sensor. In addition, a stable and reliable tire–road friction coefficient (TRFC) estimation method is adopted, and the desired slip ratio (DSR) is observed as the target that the rear wheels cycle around. At the upper level of the hierarchical control structure, the desired clamping forces of the rear wheels are generated using a sliding mode control (SMC) technique, and the control objective is to track the DSR to make full use of the road condition. At the lower level, the motor is controlled to track the desired clamping force generated from the upper controller. The hardware-in-the-loop (HIL) experimental results demonstrate the effectiveness and high tracking precision of the proposed strategy under different road conditions, and the estimation parameters based on the proposed observers are timely and accurate to satisfy the control requirements.

Improved Golden Jackal Optimization for Optimal Allocation and Scheduling of Wind Turbine and Electric Vehicles Parking Lots in Electrical Distribution Network Using Rosenbrock’s Direct Rotation Strategy

In this paper, a multi-objective allocation and scheduling of wind turbines and electric vehicle parking lots are performed in an IEEE 33-bus radial distribution network to reach the minimum annual costs of power loss, purchased grid energy, wind energy, PHEV energy, battery degradation cost, and network voltage deviations. Decision variables, such as the site and size of wind turbines and electric parking lots in the distribution system, are found using an improved golden jackal optimization (IGJO) algorithm based on Rosenbrock’s direct rotational (RDR) strategy. The results showed that the IGJO finds the optimal solution with a lower convergence tolerance and a better (lower) objective function value compared to conventional GJO, the artificial electric field algorithm (AEFA), particle swarm optimization (PSO), and manta ray foraging optimization (MRFO) methods. The results showed that using the proposed method based on the IGJO, the energy loss cost, grid energy cost, and network voltage deviations were reduced by 29.76%, 65.86%, and 18.63%, respectively, compared to the base network. Moreover, the statistical analysis results proved their superiority compared to the conventional GJO, AEFA, PSO, and MRFO algorithms. Moreover, considering vehicles battery degradation costs, the losses cost, grid energy cost, and network voltage deviations have been reduced by 3.28%, 1.07%, and 4.32%, respectively, compared to the case without battery degradation costs. In addition, the results showed that the decrease in electric vehicle availability causes increasing losses for grid energy costs and weakens the network voltage profile, and vice versa.

Analytical Modeling of Heat Transfer Coefficient Analysis in Dimensionless Number of an Electric Parking Brake Using CFD

The present study intends the development of an electric parking brake (EPB) for commercial vehicles (CVs). CVs with EPB applications are currently available in an entirely different set of issues than EPB applications on passenger cars, which are presently widely used. Safe parking requires much more focus with an order of magnitude, more thermal capacity, brake mass, and clamp pressures. In the first instance, heat loss from the brake disc was estimated. The investigations also allowed for precise prediction of radiative heat loss by defining surface emissivity. The parameters of air movement, convective heat transfer coefficients, and velocities were investigated, and validation was done with the CFD model. When the temperature dropped to 252 °C, the maximum estimated value of the Nusselt number was 72.25. Nusselt number pattern that looks identical over the arc surface yields 13.38 percent better results. Nu values at maximum temperature were calculated to be 80.5 and 82.6 at 251.8 °C. The “hconv” value was 4.1 percent lower than in the arc region, with the highest value at 400°C being 11.5 W/m2K. The present study adopted unique approach and obtained brake disc temperature and the coefficient of convective heat transfer on disc friction surfaces and hat regions. CFD modeling was done during the cooling phase to evaluate flow patterns and “hconv” fluctuation across the entire disc brake surface area. The mathematical modeling and adopted methodology for computing heat transfer coefficients for different disc regions have helped to better understand of a CV brake disc heat dissipation.

A Method for Disturbance-Tolerant “Sensorless” Angle Measurement of DC Motors

“Sensorless” measurement of the angle of rotation or speed of direct current motors using periodic oscillations in the electrical signals is usually very susceptible to errors. This is caused by the occurrence of frequencies in the signals that do not correspond to the expected frequency. In this article, a new method is presented, which is robust against these influences and is, thus, able to provide a much more reliable angle or speed signal. For this purpose, the causes of the frequencies occurring in the electrical signals are discussed first. Based on general considerations incorporating these effects, the derivation of a general scheme and the associated requirements are presented. The algorithm is then developed in detail and implemented within the context of an application example using an electric parking brake of a motor vehicle. Finally, the process is experimentally validated using three different motor types under different operating conditions and the specific properties of the method are discussed.

Sizing and Energy Management of Parking Lots of Electric Vehicles Based on Battery Storage with Wind Resources in Distribution Network

In this paper, an optimal sizing and placement framework (OSPF) is performed for electric parking lots integrated with wind turbines in a 33-bus distribution network. The total objective function is defined as minimizing the total cost including the cost of grid power, cost of power losses, cost of charge and discharge of parking lots, cost of wind turbines as well as voltage deviations reduction. In the OSPF, optimization variables are selected as electric parking size and wind turbines, which have been determined optimally using an intelligent method named arithmetic optimization algorithm (AOA) inspired by arithmetic operators in mathematics. The load following strategy (LFS) is used for energy management in the OSPF. The OSPF is evaluated in three cases of the objective function such as minimizing the cost of power losses, minimizing the network voltage deviations, and minimizing the total objective function using the AOA. The capability of the AOA is compared with the well-known particle swarm optimization (PSO) and artificial bee colony (ABC) algorithms for solving the OSPF in the last case. The findings show that the power loss, voltage deviations, and power purchased from the grid are reduced considerably based on the OSPF using the AOA. The results show the lowest total cost of energy and also minimum network voltage deviation (third case) by the AOA in comparison with the PSO and ABC with a higher convergence rate, which confirms the better capability of the proposed method. The results of the first and second cases show the high cost of power purchased from the main grid as well as the high total cost. Therefore, the comparison of different cases confirms that considering the cost index along with losses and voltage deviations causes a compromise between different objectives, and thus the cost of purchasing power from the main network is significantly reduced. Moreover, the voltage profile of the network improves, and also the minimum voltage of the network is also enhanced using the OSPF via the AOA.

A decentralized granular-based method to analyze multi-area energy management systems including DGs, batteries and electric vehicle parking lots

A method to analyze multi-area optimal power flow in novel energy management systems is proposed and studied in this paper. The studied power network consisted batteries, distributed generators and electric parking lots. A straightforward granular-based method is introduced to maintain the simplicity of the calculations while the independency of areas is preserved. In this case, a three-area power network as a multi-area power network problem is chosen to test and approve the applicability of the proposed method in terms of accuracy, simplicity, preserving independency, and not requiring any control or initial parameters. According to the results, maximum error is 0.0009 pu in the selected case study. Moreover, two valued variables namely operation cost and voltage deviation are selected as the two fundamental objective functions to be analyzed both multi-objectively and solely. Furthermore, in this paper, soon-to-be-indispensable electric vehicle parking lots and distributed generators are also utilized to optimize operation cost (up to 49.28%) as well as voltage deviation (up to 48.99%). Also, the influence of each area on one another in multi-area layout is studied. In one scenario, the third area is equipped with battery and fuel cell to improve voltage deviation of itself (40.42%) as well as first and second area 12% and 15.4%, respectively.

Numerical and Experimental Investigation of Compressible-Brake-Fluid Flow Characteristics and Brake-Bleeding Performance in EPB Caliper

This study investigates the compressible-brake-fluid flow characteristics within an electric parking brake (EPB) caliper during the bleeding cycles, subsequently determines the fundamental cause for reduction in brake-bleeding performance, and suggests a new design for its improvements. Three-dimensional simulation validation of the brake-fluid consumption curve is conducted through the parameter study of the air mass flow and bulk modulus. A numerical approach utilizing a three-phase (air, brake-fluid, and brake-fluid vapor) mixture model and a standard k-ω turbulence model is adopted to investigate the flow field details. Based on the unsteady simulation results and experimental verifications for the current and new models of the nut-spindle of a driving part in the EPB caliper, the primary cause for the reduction in the bleeding performance in the EPB caliper is determined to be the trapped air in the thread gap and in the space between the spindle and nut-spindle. Consequently, the head chamfer effect for the nut spindle is beneficial for removing trapped air and leads to performance improvement of 30.3 %.

Functional Safety for Developing of Mechatronic Systems - Electric Parking Brake Case Study

The electric parking brake (EPB) system as the complex mechatronic system consists of the actuators that generate the clamping force necessary to hold the vehicle safe, the conventional calipers that convert clamp force into brake torque, electronic hardware with the Electronic Control Unit (ECU), cable harness and switches and especially the control software providing the functions that the driver will experience. Like most of the modern automotive components, the EPB is equipped with embedded electronic systems that include ECU, electronic sensors, signals, bus systems, and coding. Due to the complex application in electrical, electronics and programmable electronics, the need to carry out detailed safety analyses that are focused on the potential risk of malfunction is crucial for automotive systems. This paper describes a possible division of the EPB sub-functions between the supplier the wheel brakes and the supplier which supplying the ECU. Functional safety must be a guarantee with concerning the overall vehicle system. Functional safety is according to the requirements of the ISO 26262 standard and in the context of this paper relates solely to the E/E components (electrical and/or electronic) of the EPB. This paper covers the hazard analysis and risk assessment relevant to the EPB control software, and the derived allocation of ASIL risk levels to the EPB software elements of the functional architecture of the EPB.

Stochastic Optimal Scheduling of Microgrids Considering Demand Response and Commercial Parking Lot by AUGMECON Method

Regarding the advances in technology and anxieties around high and growing prices of fossil fuels, government incentives increase to produce cleaner and sustainable energy through distributed generations. This makes trends in the using microgrids which consist of electric demands and different distributed generations and energy storage systems. The optimum operation of microgrids with considering demand-side management increases efficiency and reliability and maximize the advantages of using distributed generations. In this paper, the optimal operation scheduling and unit commitment of generation units installed in a microgrid are investigated. The microgrid consists of technologies based on natural gas that are microturbine and phosphoric acid fuel cell and technologies based on renewable energy, including wind turbine and photovoltaic unit along with battery energy storage system and plug-in electric vehicle commercial parking lot. The goal of the paper is to solve a multi-objective problem of maximizing revenues of microgrid operator and minimizing emissions. This paper uses an augmented epsilon constraint method for solving the multi-objective problem in a stochastic framework and also implements a fuzzy-based decision-maker for choosing the suitable optimal solution amid Pareto front solutions. This new model implements the three type of the price-based and incentive-based demand response program. It also considers the generation reserve in order to enhance the flexibility of operations. The presented model is tested on a microgrid and the results demonstrate the efficacy of the proposed model economically and environmentally compared to other methods.

Research on Planning and Layout of Electric Vehicle Public Charging Piles in Historical and Cultural Street Based on Big Data

Nowadays, with the development and popularization of electric vehicles, electric vehicle charging pile has become an important green infrastructure in cities. The optimization of the layout of charging piles in the urban area has drawn the attention of more and more research groups. However, only a few of them concerned the distribution of piles in the historical distinct. In this paper, we proposed to use big data tools to obtain parking and electric parking space information, such as the parking lots, on-street parking spaces and plazas. We tried to transform them with the charging function. we also proposed a “P + W” mode, which takes advantage of the present parking lots and street parking area. We wanted to optimize the current layout and offer a new layout plan for further research and application.

How to Make the Charging Simple, Convenient and Efficient

With the large-scale application of electric vehicles (EV) in the world and also in China, the contradiction between the EV and charging stations has become more and more prominent. People always cannot easily find the charging stations or when they find them finally found they do not work. To connect the vehicle, charging station/pile and end-users for making the charging simple, convenient, efficient and visible is becoming very important. People need a platform to tell them where, when and how to charge for their EV. Matrix Mobility is focusing on realizing this comprehensive charging solution together with OEM, charging point operator (CPO), electric power company and parking lots by using big data analysis. Matrix Mobility installs the charging solution into the car unit before cars go off production line and meanwhile integrates the same function into OEM’s own APP with opening API to help end-users increase their charging experience.

ITDP-Robot: Design of An Intelligent Transport Dispatch Parking Robot

In this paper, a novel electric autonomous parking robot prototype was proposed, which aims to address the parking hassle caused by the imbalance between the vehicle ownership and the amount of the parking spaces. The mechanical structure was elaborately designed to allow the parking robot to adapt to vehicles with different wheelbases and tracks. The electrical structure was constructed with the aim of X-by-wire and distributed component-based control concept. To be capable of autonomous driving, the parking robot software system based on ROS was designed with the capability of environment perception, self-localization and path planning. Furthermore, a simulation environment based on Gazebo was built in order to simplify the development of the parking robot’s autonomous driving algorithms and validate those algorithms’ robustness. Though this parking robot is under the prototype stage, the dispatch strategy and the convenience for parking were also considered. Compared with the state-of-art parking robot, this parking robot is not only capable of working indoor parking lots but also the complex outdoor environments.

Analysis of mechanical and electrical parking brakes

The article discusses the analysis of mechanical and electrical parking brakes. The article begins with a description of their operating principle, and then an examination of the technical condition of the parking brake system followed by appropriate conclusions.

Development and experimental validation of an automatic parking brake system with less driveline sensor

Electrical Parking Brake (EPB) has been popularly used in passenger cars over the past ten years. With the help of the several kinds of sensors mounted in driveline for the total traction force estimation, EPB can obtain well performance on drive-off assistance and automatic parking brake. Furthermore, its AUTOHOLD function can realize automatic parking brake and ease the driver. However, given that the higher cost and complexity of this traction force estimation method based on the driveline sensors and its slower response resulted by applying maximum parking force for safety parking while driving off, a novel automatic parking brake system without these transmission system sensors, such as clutch position sensor for the cars with manual transmission, is proposed in this paper, including its control scheme and application test. Firstly, the indirect judgement method of the appropriate moment to release the parking brake, which is based on the car pitch moment when it drives off, is introduced according to the force analysis when the car is ready to go. Then a pragmatic mass estimation method for proper brake force calculation is proposed for improving the drive-off performance. In addition, for the convenience and drivability of skillful driver, as well as the system reliability, a mechanical redundant design to reserve the conventional handbrake lever is also described. Finally, various simulations based on CarSim software and road tests are performed to validate its effectiveness.

Optimal placement and sizing of PV systems and electric parking lots considering reactive power capability and load variation

ABSTRACTPower systems should operate in reliable, stable, and efficient conditions. Addition of new generation units or loads to the power systems may change their performance. Therefore, appropriate decisions should be made to manage these elements to improve the power system performance. In this study, optimal placement and sizing of photovoltaic systems and electric parking lots (EPLs) are studied considering the reactive power capability of the inverters and load variation in a 24-h period. For the EPL, a proper charge/discharge scheme (CDS) is initially proposed to flatten the daily load profile; then the EPL with the associated CDS is considered to find its optimal location. Voltage profile, energy losses, bus, and line voltage stability are considered as the objectives of the problem. Genetic algorithm and backward–forward power flow method are utilised to solve the problem considering the IEEE 33-bus system. The results show that all objectives are improved utilising the proposed method.

Performance of the Transmission Parking Mechanism of a Battery Electric Vehicle Simulated with Adams Software

The electric parking mechanism is studied for an electrically controlled two-speed auto transmission that is being developed for electric vehicles. Safety requirements include low-speed safe parking, reliable self-lock and the avoidance of abnormal parking. A dynamic model of the parking mechanism is established and analyzed using Adams software. Finally, failure of the parking mechanism due to wear is observed in bench testing and compared with experimental results after optimization.

An Electric Parking Brake Motor-On-Caliper actuator model for robust drive away control design

Electric Parking Brake system is the automation of traditional manual vehicle parking brake system. Naturally, an automation in automotive field includes an improvement of vehicle features that will become, in short time, normal production functionalities, since forever present on vehicles for users. Certainly, EPB control design is a robust design which is influenced by a series of different plant disturbances / uncertainties as: available vehicle battery voltage, ambient/caliper/pad temperatures, vehicle harness length, and normal braking hydraulic pressure already present on caliper spindle. Furthermore EPB system performance has a big impact on vehicle safety, ECE 13H braking legislation part related to parking brakes prescribes many different performance thresholds, static and dynamic, that are easily translated in low level control design requirements. In this context, paper presents: an algebraic mathematical model, including linear and non-linear parts of braking motor-on-caliper, dynamic response identification of electric parking brake actuator by least square identification experiments, linearization of identified non-linear model, observability analysis of identified linear model, and control of Motor on Caliper (MoC) validated with MIL and HIL approach. The simulation and experimental results on a motor-on-caliper test bench, carried out in FCA Technical Center, show that designed identified model is well matched with the clamping force actuator, and it can be useful in drive away robust control logics development.

Heat dissipation from a stationary brake disc, Part 2: CFD modelling and experimental validations

Following from the analytical modelling presented in Part 1, this paper details a comprehensive computational fluid dynamics modelling of the three-dimensional flow field around, and heat dissipation from, a stationary brake disc. Four commonly used turbulence models were compared and the shear stress turbulence model was found to be most suitable for these studies. Inferior cooling of the anti-coning disc type is well known but the core cause in static conditions was only now established. The air flow exiting the lower vane channels at the inner rotor diameter changes direction and flows axially over the hat region. This axial flow acts as a blocker to the higher vane inlets, drastically reducing convective cooling from the upper half of the disc. The complexity of disc stationary cooling is further caused by the change of flow patterns during disc cooling. The above axial flow effects slowly vanish as the disc temperatures reduce. Consequently, convective heat transfer coefficients are affected by both, the change in the flow pattern and decrease in air velocities due to reduced air buoyancy as the disc cools down. As in Part 1, the special thermal rig was used to validate the computational fluid dynamics results quantitatively and qualitatively. The former used numerous thermocouples positioned strategically around the brake disc, with the latter introducing the concept of laser generated light plane combined with a smoke generator to enable flow visualisation. Predicted average heat transfer coefficients using computational fluid dynamics correlate well with the experimental values, and even two-dimensional analytical values (as presented in Part 1) reasonably closely follow the trends. The results present an important step in establishing cooling characteristics related to the electric parking brake application in commercial vehicles, with future publications detailing heat transfer from the entire brake assembly.