No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Smart Panel Board for EV Standard Chargers and Its Control Method
Abstract
This study proposes an electric vehicle (EV) smart panel board and its control method on the basis of charging scheduling. The proposed system consists of batteries, a three-phase battery charger, three single-phase inverters, transfer switches for electric power distribution, and a controller. The three-phase battery charger usually charges the batteries at midnight when electric rates are cheap and in light load. When the electric power consumption of the EV standard chargers connected to one phase of the power line is relatively large or when a blackout occurs, the electric power stored in the battery is supplied by discharging through the inverters to the EV standard chargers. As a result, the value of peak load and the charging electric power quantity supplied from a utility grid are reduced, and the current unbalance is improved. The usefulness of the proposed system is confirmed through simulations, experiments, and case studies.
In this paper, we have analyzed the power consumption property of EVs(Electric Vehicles) chargers established in a public place, proposed reasonable demand factors by the number of established EV chargers and its control method in apartments. The optimization of power system and the suppression of the peak load can be controlled through the proposed demand factors and charging scheduling control algorithm. In this paper, electrical design and an case analysis were carried out on a sample apartment complex to prove the effectiveness of the power system. As a result, emergency power transformer capacity has been reduced by approximately 25%, and we have confirmed that the electric rates saving and the control of peak load value is possible.
Most of the load distributions in low voltage power feeder distribution systems are designed with approximately balanced and connected at the three phase four wire systems. However, in the user power distribution systems, most of the loads are single & three phase and unbalanced, generating load unbalance. Load unbalance factor is mainly affected by the impedance of load system. Unbalanced current will draw a highly unbalanced voltage. This paper presents a new calculation method for unbalance factor under the load variation at the three phase four wire system. Load unbalance factor is measured by the power quality measurement apparatus and compared with the current unbalance factor. Two methods are indicated similar results.
This paper reviews the current status and implementation of battery chargers, charging power levels, and infrastructure for plug-in electric vehicles and hybrids. Charger systems are categorized into off-board and on-board types with unidirectional or bidirectional power flow. Unidirectional charging limits hardware requirements and simplifies interconnection issues. Bidirectional charging supports battery energy injection back to the grid. Typical on-board chargers restrict power because of weight, space, and cost constraints. They can be integrated with the electric drive to avoid these problems. The availability of charging infrastructure reduces on-board energy storage requirements and costs. On-board charger systems can be conductive or inductive. An off-board charger can be designed for high charging rates and is less constrained by size and weight. Level 1 (convenience), Level 2 (primary), and Level 3 (fast) power levels are discussed. Future aspects such as roadbed charging are presented. Various power level chargers and infrastructure configurations are presented, compared, and evaluated based on amount of power, charging time and location, cost, equipment, and other factors.
This paper proposes a boost type inverter system to compensate the voltage sag has appeared in voltage sources. If the voltage sag has appeared in input voltage, a boost converter would be operated to compensate it in the boost type inverter system. The boost converter would not be operated when the magnitude of input voltage is more than 90 %, and the output voltage is kept constant by a direct-quadrature frame controller in the single-phase PWM inverter. A 300 W class boost type inverter system was simulated, and the validity of the proposed system was verified by carrying out experiments.
A summary of the actual state of battery charger harmonics is presented. The effect of harmonic distortion on the distribution system, especially on distribution transformers, is analyzed. A program was developed that allows the consideration of the transformer life consumption as a function of the battery charger characteristics and charging algorithm. The program is considered to be a distribution planning and management tool. The proposed tool can be easily applied to determine the optimum charging time as a function of the existing load, ambient temperature, and time of day. From the study it can be deduced that a direct connect-and-charge scheme can be detrimental to the transformer life, especially under high temperature and large load. Calculations show the existence of a quadratic relationship between the transformer life consumption and the total harmonic distortion (THD) of the battery charger current. Furthermore, the current THD should be limited to 25 30% in order to have a reasonable transformer life expectancy.
Item and review criterion of the environmental impact assessment on building and maintenance business (redevelopment & reconstruction)
- Seoul Metropolitan Government
Seoul Metropolitan Government, "Item and review
criterion of the environmental impact assessment on
building and maintenance business (redevelopment &
reconstruction),"The Environmental Impact Assessment
Bylaw, Clause 29, Article 2, 2011.
A development of the software to estimate economics for combined heat and power generation systems in apartment estates
- Housing Land
- Research Institute
- Korea
Model for EV charging distribution system in apartments
- Y M Ki
- B I Kim
- Y M Ko
- C H Oh
- S H Yang
- S Y Lee
Y. M. Ki, B. I. Kim, Y. M. Ko, C. H. Oh, S. H. Yang,
and S. Y. Lee, "Model for EV charging distribution
system in apartments", Proceedings of Spring Joint
Conference on the KIIE-KORMS, pp. 1804-1812, 2014.
Consumer's Electrical Installation Guide, Section 115
Consumer's Electrical Installation Guide, Section 115,
Korea Electric Association, 2006.
Boost type inverter system for compensation of voltage sag
- S Y Lee
- Y M Seo
- M S Kim
- S C Hong
S. Y. Lee, Y. M. Seo, M. S. Kim, and S. C. Hong,
"Boost type inverter system for compensation of
voltage sag," Proceedings of International Conference
on Power Electronics-ECCE Asia, pp. 2757-2762, 2011.