• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.2
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• pp.47-53
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• 2015

The study concerning about the grid connection of the large-capacity energy storage system(ESS) is increasing. However, the transient study such as lightning or switching surge necessarily occurred at power system with ESS has been hardly performed. Therefore, this paper performs the analysis of lightning surge in distribution system with ESS using electromagnetic transient program(EMTP). The battery model in Matlab/Simulink is modeled by EMTP, which is the specialized software for power system transient study. Also, the bi-directional power electronics for interconnection of the battery and distribution system are modeled by EMTP. When the lightning is occurred at interconnection point of ESS, this paper simulates the existence of ESS and operation conditions of ESS and analyzes the surge in distribution system and ESS according to the various conditions.

• Journal of Korea Society of Digital Industry and Information Management
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• v.15 no.2
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• pp.11-17
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• 2019

As interest in the efficiency use of energy has been recently rising, studies have been performed in utilizing various types of eco-friendly green energy and natural energy. Especially there has been rapidly increase in the fields using ESS (Energy Storage System), which is the technology for storing the energy from nature. The application fields of ESS is continuously growing and expanding to various types of technologies. However, in recent years there have been continuing problems with the safety of ESS. And related researches are going on. In this paper, we has proposed a system structure to utilize more secure ESS and has monitored the system status of ESS in real time by using smart phone app. This paper has also proposed a new method to configure secure ESS by implementing GUI (Graphical User Interface) to control the system. And then explain experimental results to investigate the efficiency of the proposed ESS.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.5
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• pp.592-598
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• 2007

The fuel charge is getting higher in navigation cost. Therefore, shipowners try to find the method for reducing oil consumption. ESS(Energy Saving System) is one of he method. ESS is the system consisted with two inverters, ESS control unit and monitoring system. Two inverters control two main sea water cooling pumps. In the ESS control Unit, the control algorithm finds optimized point to decrease a power consumption of main sea water cooling pumps. Monitoring system observes ESS not to work improperly. ESS is experimented in the laboratory with real condition and analyzed in every view. After experiment, the result of the experiment shows that the control algorithm works correctly and safely. ESS has a plan to be operated in the ship soon. In that case, additional devices are needed to connect ESS with cooling system of the vessel. So the development of addition device is needed and being studied.

• KEPCO Journal on Electric Power and Energy
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• v.2 no.2
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• pp.227-232
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• 2016

To test the effectiveness of using an energy storage system for frequency regulation, the Energy New Business Laboratory at KEPCO Research Institute installed a 4 MW energy storage system (ESS) demonstration facility at the Jocheon Substation on Jeju Island. And after the successful completion of demonstration operations, a total of 52 MW ESS for frequency regulation was installed in Seo-Anseong (28 MW, governor-free control) and in Shin-Yongin (24 MW, automatic generation control). The control system used in these two sites was based on the control system developed for the 4 MW ESS demonstration facility. KEPCO recently finished the construction of 184 MW ESS for frequency regulation in 8 locations, (e.g. Shin-Gimjae substation, Shin-Gaeryong substation, etc.) and they are currently being tested for automatic operation. KEPCO plans to construct additional ESS facilities (up to a total of about 500 MW for frequency regulation by 2017), thus, various operational tests would first have to be conducted. The high-speed characteristic of ESS can negatively impact the power system in case the 500 MW ESS is not properly operated. At this stage we need to verify how effectively the 500 MW ESS can regulate frequency. In this paper, the effect of using ESS for frequency regulation on the power system of Korea was studied. Simulations were conducted to determine the effect of using a 524 MW ESS for frequency regulation. Models of the power grid and the ESS were developed to verify the performance of the operation system and its control system. When a high capacity power plant is tripped, a 24 MW ESS supplies power automatically and 4 units of 125MW ESS supply power manually. This study only focuses on transient state analysis. It was verified that 500 MW ESS can regulate system frequency faster and more effectively than conventional power plants. Also, it was verified that time-delayed high speed operations of multiple ESS facilities do not negatively impact power system operations. It is recommended that further testing be conducted for a fleet of multiple ESSs with different capacities distributed over multiple substations (e.g. 16, 24, 28, and 48 MW ESS distributed across 20 substations) because each ESS measures frequency individually. The operation of one ESS facility will differ from the other ESSs within the fleet, and may negatively impact the performance of the others. The following are also recommended: (a) studies wherein all ESSs should be operated in automatic mode; (b) studies on the improvement of individual ESS control; and (c) studies on the reapportionment of all ESS energies within the fleet.

• Journal of Applied Reliability
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• v.18 no.3
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• pp.229-239
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• 2018

Purpose: There is a difficulty in Environmental Stress Screening (ESS) test design for weapon system's electrical/electronic components/products in small and medium-sized enterprises. To overcome this difficulty, I propose an easy ESS test design approach algorithm that is optimized with only one environment tolerance design information parameter (${\Delta}T$). Methods: To propose the mass production weapon system ESS test design for cost-effective optimization, I define an optimum cost-effective mathematical model ESS test algorithm model based on modified MIL-HDBK-344, MIL-HDBK-2164 and DTIC Technical Report 2477. Results: I clearly confirmed and obtained the quantitative data of ESS effectiveness and cost optimization along our ESS test design algorithm through the practical case. I will expect that proposed ESS test method is used for ESS process improvement activity and cost cutting of mass production weapon system manufacturing cost in small and medium-sized enterprises. Conclusion: In order to compare the effectiveness of the proposed algorithm, I compared the effectiveness of the existing ESS test and the proposed algorithm ESS test based on the existing weapon system circuit card assembly for signal processing. As a result of the comparison, it was confirmed that the test time was reduced from 573.0 minutes to 517.2minutes (9.74% less than existing test time).

• The Transactions of the Korean Institute of Power Electronics
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• v.23 no.2
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• pp.101-105
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• 2018

Shortage of electric power occurs frequently along with increased electric power demand. ESS is a precaution to solve this issue. Household ESS has a capacity of approximately 3 kW/7 kWh. Household ESS batteries are typically designed with nominal voltages between 40 and 50 V. To connect household ESS with a 220 V AC system, low battery voltages in power conditioning system (PCS) should be boosted. To boost low battery voltage and match it with AC grid voltage, the use of a transformer for a commercial frequency can be considered. To attenuate switching harmonics of the household single-phase ESS-PCS, LC filter can be installed in two positions: on the primary side or on the secondary side of a transformer. A method has been used generally in single-phase inverters for the ESS-PCS. In another method, however, the output efficiency of the ESS-PCS may be decreased. Parasitic components of the transformer can affect voltage losses, when the square wave with the switching frequency in the ESS-PCS is passed through the transformer windings. In this work, the characteristics of the transformer according to the position of an LC filter are investigated for household single-phase ESS-PCS.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.67 no.1
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• pp.37-41
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• 2018

In this paper, the ESS(Energy Storage System) is interconnected in order to reduce the maximum load in the distribution system and the target location of the ESS is set to be close to the rated voltage. We also applied the weights to nodes with large capacity and number of customers in the system. In the future, the interconnected location of the ESS was determined until 2029 in consideration of the load increase rated of the system. We propose a cooperative decision algorithm of interconnected location of ESS for Power Distribution System.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.1
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• pp.29-34
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• 2018

The systems associated with the ESS never stop. It runs 24 hours everyday. The system must be managed to run. The ESS system should perform normally even if the power IT equipment fails or communication failure occurs. Therefore, there is a need for a system that actively addresses, manages and controls the high precision power data of the ESS, even if a variety of failures occur. I would like to propose a power management communication unit to cope with the occurrence of communication failure. This paper also includes an integrated management system that can perform micro grid site management, maintenance and monitoring for the ESS system connected with the solar power generation facility.

• Journal of IKEEE
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• v.23 no.3
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• pp.1027-1032
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• 2019

In this paper, we had developed an algorithm that can cope with all the economic variables that may occur in the operation of PV-ESS system by developing the algorithm for the operation method of PV-ESS connected system. Based on this, the optimal operation schedule of PV-ESS was decided to minimize the electric charges of customers. Through this, we developed a three-dimensional dynamic planning method based on case generation to determine the optimal PV-ESS operation schedule stably even when exogenous variables change.

• Journal of Energy Engineering
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• v.23 no.4
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• pp.106-111
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• 2014

In order to manage the gradual increase of electricity demand, the United States, Japan, and Europe are seeking to achieve overall change of electric power system by introducing solutions such as smart grid. Among these solutions, there are various research projects regarding the Electricity Storage System (ESS), which aims to promote the efficient usage of electricity and grid system of new and renewable energy system. Korean government revised the law by including ESS in new and renewable energy facilities to accelerate ESS deployment. Following the same direction of the government policy, this study suggests methodologies of setting REC weighted value that guarantees investment financial feasibility when new and renewable power producers install ESS.