Current Issue : October - December Volume : 2020 Issue Number : 4 Articles : 5 Articles
The smart grid concept enables demand-side management, including electric vehicles\n(EVs). Thus way, some ancillary services can be provided in order to improve the power system\nstability, reliability, and security. The high penetration level of renewable energy resources causes\nsome problems to independent system operators, such as lack of primary reserve and active power\nbalance problems. Nowadays, many countries are encouraging the use of EVs which provide a\ngood chance to utilize them as a virtual power plant (VPP) in order to contribute to frequency event.\nThis paper proposes a new control method to use EV as VPP for providing primary reserve in smart\ngrids. The primary frequency reserve helps the power system operator to intercept the frequency\ndecline and to improve the frequency response of the whole system. The proposed method calculates\nthe electric vehiclesâ?? primary reserve based on EVsâ?? information, such as the state of charge (SOC),\nthe arriving time and the vehicleâ??s departure time. The effectiveness of the proposed scheme is verified\nby several simulation scenarios on a real-world modern power system with different generating\nunits, such as conventional power plants, renewable energy resources, and electric vehicles....
This paper determines the profitability of the primary frequency regulation (FR) service\nconsidering the wear of the electric vehicle (EV) battery as a cost. To evaluate the profitability of the\nFR service, the cost of degradation from FR provision is separated from the degradation caused by\ndriving usage. During FR, the power response is proportional to the frequency deviation with full\nactivation power of 9.2 kW, when deviations are larger than 100 mHz. The degradation due to FR\nis found to be an additional...............
The energy density of canode materials for lithium-ion batteries has a major impact on the driving range of electric vehicles. In\norder to study the charge-discharge characteristics and application feasibility of Li-NiMnCo lithium-ion batteries for vehicles, a\nseries of charge and discharge experiments were carried out with different rates of Li-NiMnCo lithium-ion batteries (the ratio of\nnickel, cobalt, and manganese was 5 : 2 : 3) in constant-current-constant-voltage mode. Firstly, a set of charge-discharge\nexperiments were performed on different types of single-cell lithium-ion batteries. The results show that, under temperature\nconditions, the charge and discharge voltage-capacity curves of the four different types of Li-NiMnCo lithium batteries\nmentioned in the paper are not much different, and the charge-discharge characteristic curves are similar, indicating that\ndifferent types of batteries with the same material composition have similar charge and discharge characteristics.\nSubsequently, a series of charge and discharge tests with different rates were conducted on such ternary lithium batteries.\nThe characteristic curves with different charge-discharge rates indicate that this new type of ternary lithium battery has\nhigh current charge and discharge capability and is suitable for use in new energy electric vehicles. In addition, by\nanalyzing the voltage-SOC curve under different magnification conditions, it is known that there is an approximate linear\nrelationship between the battery voltage value and the SOC within a certain SOC range. The SOC value can be evaluated\nby the battery voltage, which should be controlled within a reasonable range to avoid overcharge or overdischarge of\nbattery, thereby, causing permanent damage to the battery....
This work presented a nonlinear control for a reversible power buckâ??boost converter (BBC)\nin order to control energy storage in a supercapacitor (SC) used in hybrid electric vehicles (HEV).\nThe aim was to control a power converter in order to satisfy the following two requirements: (i) perfect\ntracking of SC current to its reference signal and (ii) asymptotic stability of the closed-loop system.\nThe two objectives were achieved using an integral sliding mode control. In order to validate the\nproposed approach, an experimental prototype was built. The controller was integrated into dSPACE\nprototyping systems using the DS1202 card. It was clearly shown, using formal analysis, simulation,\nand experimental results, that the designed controller metall the objectives, namely, the stability of\nthe system and the control of the current at its reference....
The number of connected cars and the massive consumption of digital content on\nthe Internet have increased daily. However, the high mobility of the vehicles, coming from patternsâ??\nvariation over time, makes efficient large-scale content distribution quite challenging. In light\nof this, the emerging Vehicular Named Data Network (VNDN) architecture provides support\nfor content-centric network communications and caching capabilities, which allows reliable and\nlarger-scale content delivery over Vehicular Ad-Hoc Networks (VANETs). This notwithstanding, the\nhigh number of interest packets in VNDN tends to introduce broadcast storm occurrences during\nthe cache discovery process. Thus, network performance degradation comes up for the influence\nof both increased packet loss rates and delays on content recovery during communication between\nvehicles. This work proposes a new cache discOVEry pRoTocol (OVERT VNDN), which combines the\ncomputational geometry and degree centrality concepts to tackle the VNDN performance degradation\nchallenges and issues. The main idea behind OVERT VNDN is to choose the most appropriate relay\nvehicles to engage interest packetsâ?? delivery within the VNDN, seeking to achieve higher network\nperformance by optimizing broadcast storm incidence. The obtained results suggest that OVERT\nVNDN outperforms its competitor in the following key performance indicators: (i) improving the\ncache discovery process by 120.47%; (ii) enhancing the content delivery rate by 43%; and (iii) reducing\nthe number of interest packets by 80.99%....
Loading....