Determination and Application of Maximum Efficiency Curve of Crawler Electric Tractor Motors

With the excessive use of fossil fuels such as oil, the energy crisis and environmental pollution have become important problems related to people’s livelihoods. In agriculture, as a new type of green agricultural machinery, the electric tractor has the advantages of high energy utilization and no exhaust emission. The motor is the core component of an electric tractor’s drive system. Its characteristics and control directly affect a tractor’s operating efficiency, operating quality, and energy consumption. A motor drive control scheme based on a characteristic curve at the maximum efficiency of an electric motor was adopted to address the problems of low motor power utilization and short continuous operation time on a full charge in electric tractors. By leveraging methods to obtain characteristic curves at the lowest fuel consumption for gasoline engines, we determined the characteristic curve at the maximum efficiency for a motor in a crawler-type electric tractor. Plowing is the most basic form of tractor operation, and it represents the agricultural work that accounts for most of a tractor’s use. A field test was conducted on the drive control in plowing operation based on the curve, and the energy consumed to plow each m2, continuous plowing operation time on a full charge, and operating efficiency were tested. The test results showed plowing power consumption per m2 of about 8.40 × 10−3 kWh and work efficiency of 707.07 m2/h. Compared with the traditional tractor, the cost of plowing 1 m2 by the crawler-type electric tractor was reduced by 20.3%–32.5%. Because the control improves operating efficiency, battery energy consumption is reduced and continuous operation time is extended; hence, the control achieves its purpose.

Charge completeness and the massless charge lattice in F-theory models of supergravity

We prove that, for every 6D supergravity theory that has an F-theory description, the property of charge completeness for the connected component of the gauge group (meaning that all charges in the corresponding charge lattice are realized by massive or massless states in the theory) is equivalent to a standard assumption made in F-theory for how geometry encodes the global gauge theory by means of the Mordell-Weil group of the elliptic fibration. This result also holds in 4D F-theory constructions for the parts of the gauge group that come from sections and from 7-branes. We find that in many 6D F-theory models the full charge lattice of the theory is generated by massless charged states; this occurs for each gauge factor where the associated anomaly coefficient satisfies a simple positivity condition. We describe many of the cases where this massless charge sufficiency condition holds, as well as exceptions where the positivity condition fails, and analyze the related global structure of the gauge group and associated Mordell-Weil torsion in explicit F-theory models.

Experimental Evaluation of Aging Indicators for Lithium–Iron–Phosphate Cells

Degradation mechanism of batteries has to be carefully studied when considering their utilization in electrical power systems. This paper presents the results of an extensive experimental campaign, through which three different lithium–iron–phosphate (LFP) cells were subjected to different electrical cycling stresses. The purpose of the campaign was to evaluate the cells’ aging, as well as to try to find parameters on the cell behavior before its end of life, able to act as state-of-life (SOL) (or aging) indicators. The considered stress consists of the cyclic repetition of fixed-duration discharge steps, followed by full charge phases. The three cells under study were subjected to the very same stress pattern but with three different discharge and charge power levels: low, medium, and high. The results showed that the end-of-discharge voltage and the cell internal resistance can be used as good SOL indicators. However, both are significant functions of the cell conditions, such as the state of charge (SOC) and the cell temperature.

SOC (STATE of CHARGE) THREE-CELL LEAD DYNAMIC BATTERY MODEL

Three-cells dynamic lead-acid battery has been widely manufactured as the latest secondary battery technology. It is being carried out by 10 cycles of charge-discharge treatment with a various types of SoC, such as 100% (Full charge 5100 mAh), 50% (2550 mAh), 25% (1275 mAh) and discharge current of 0.8A. This experiment aims to analyze the treatment of SOC conditions on the performance of the lead-acid battery. The cyclicality test has performed using a Battery Management System (BMS) by applying an electric current at charging 1 A and discharging 0.8A. The results of the SOC charging conditions at 100%, 50%, 25% respectively gave a difference in the value of voltage efficiency of 84%, 87%, 88%, capacity efficiency values of 84%, 80%, 69%, energy efficiency values of 70%, 70%, 62%. The 100% and 50% SOC treatments showed better performance and battery energy the 25% SOC treatment. This research can be a recommendation to predict the performance of the lead-acid battery model during the charging and discharging process.

Switched Capacitor DC-DC Converters: A Survey on the Main Topologies, Design Characteristics, and Applications

This work presents a review of the main topologies of switched capacitors (SCs) used in DC-DC power conversion. Initially, the basic configurations are analyzed, that is, voltage doubler, series-parallel, Dickson, Fibonacci, and ladder. Some aspects regarding the choice of semiconductors and capacitors used in the circuits are addressed, as well their impact on the converter behavior. The operation of the structures in terms of full charge, partial charge, and no charge conditions is investigated. It is worth mentioning that these aspects directly influence the converter design and performance in terms of efficiency. Since voltage regulation is an inherent difficulty with SC converters, some control methods are presented for this purpose. Finally, some practical applications and the possibility of designing DC-DC converters for higher power levels are analyzed.

Understanding Household’s Travel Costs Budget Frontier in Banda Aceh, Indonesia

This study aims to explore the constraints of the Travel Costs Budget Frontier (TCBF) before a full-charged fare is implemented for the bus system known as the “Trans Koetaradja” in the city of Banda Aceh, Indonesia. A stochastic frontier analysis was used to identify how people allocate their share of income for transportation in line with their mobility and socio-demographic characteristics. The findings showed the TCBF to be influenced by commuting trip activities, private mode usage, owning car and motorcycle and income limits. Barriers were observed to be restricting the low-medium income groups. Owning their own private modes within the low-medium income groups does mean household disbursement and could impose their transport expenditure rather than public modes usage. There is a need to devise policies considering the low-medium incomes to implement impartial full-charge to ensure affordable bus fare.

SMART CHARGING DIGITAL ACCUMULATOR BASED ON ARDUINO UNO MICROCONTROLLER

The charging device usually uses a transformer and a diode bridge. Charging the battery is called direct charging. Because it does not have a safety for the battery it can cause heat to the battery. But over time, this is no longer effective, this work can be done digitally using a microcontroller.. However, this tool is still not perfect because at the time of testing it cannot be set, sooner or later, the charging is to cut time efficiency and there is no indicator that states that the charging is full or not. Therefore, based on the description above, the researcher aims to make a smart charging accumulator based on the Arduino Uno microcotroller that is smarter, more efficient and can be used easily, with the advantage of having a tap changer on the transformer that functions as a regulator of the output voltage. as desired and piezoelectric alarm as an indicator if a full charge or there is a problem with the equipment itself.

Electrical Longboard for Everyday Urban Commuting

This paper addresses the possibility of using an electric longboard in daily travel. A conventional longboard was transformed into an electric one and tested in ICSI Rm. Valcea labs. A series of tests were performed both at the laboratory level and, under normal running conditions, outdoors. Nevertheless, two possible scenarios have been taken into consideration. First, when the electric longboard is running on a flat road with a cruise speed, while the second scenario considered was that of climbing a hill with a 10% slope. The results confirmed the expectations and showed that a full charge of the batteries allows a trip over a distance of almost 50 km on a flat route having a consumption of about 10 Wh/km. However, there are some things to keep in mind when making travel distance predictions. The quality and the profile of the road, the weight of the rider, the rider position, all of these are factors which can significantly influence the predictions regarding the travel distance. Moreover, if the optimization is taken into account, several adjustments can be done in choosing the size and wheel model, whether or not to equip the skateboard with suspensions as well as a compromise between power and energy densities when choosing battery type is essential.

SMART CHARGING DIGITAL ACCUMULATOR BASED ON ARDUINO UNO MICROCONTROLLER

The charging device usually uses a transformer and a diode bridge. Charging the battery is called direct charging. Because it does not have a safety for the battery it can cause heat to the battery. But over time, this is no longer effective, this work can be done digitally using a microcontroller.. However, this tool is still not perfect because at the time of testing it cannot be set, sooner or later, the charging is to cut time efficiency and there is no indicator that states that the charging is full or not. Therefore, based on the description above, the researcher aims to make a smart charging accumulator based on the Arduino Uno microcotroller that is smarter, more efficient and can be used easily, with the advantage of having a tap changer on the transformer that functions as a regulator of the output voltage. as desired and piezoelectric alarm as an indicator if a full charge or there is a problem with the equipment itself.