This page has only limited features, please log in for full access.
In this study, a new algorithm dealing with time-varying modes for determining and tracing multiple frequency oscillations in power systems is proposed. Multiple modes or resonance of forced and natural oscillations can have severe effects on a power system. Therefore, it is crucial to recognize the dominant natural and forced oscillations because the oscillation mode possesses time-varying features that depend on the system operating conditions or changes in the parameters. The salient features of the proposed algorithm include the use of a time-series-based approach to recognize undesired modes (including multiple oscillations over a wide frequency range), tracing time-varying modes as the power system operating condition changes, and effectively determining and applying the oscillation features before implementing the corresponding control measures in the power system. In this study, multiple frequency oscillation scenarios for the test system and practical measurement data for a recent incident that occurred in Korea Electric Power Corporation (KEPCO) system are discussed. Therefore, the proposed algorithm can be practically applied in wide-area monitoring systems, not only for a single forced oscillation or local mode detection but also for system-wide inter-area mode recognition.
Hwanhee Cho; Namki Choi; Suchul Nam; Byongjun Lee. Extended Geometric Feature Extraction Process for Detecting Multiple Frequency Oscillations in KEPCO System. IEEE Access 2021, 9, 1 -1.
AMA StyleHwanhee Cho, Namki Choi, Suchul Nam, Byongjun Lee. Extended Geometric Feature Extraction Process for Detecting Multiple Frequency Oscillations in KEPCO System. IEEE Access. 2021; 9 ():1-1.
Chicago/Turabian StyleHwanhee Cho; Namki Choi; Suchul Nam; Byongjun Lee. 2021. "Extended Geometric Feature Extraction Process for Detecting Multiple Frequency Oscillations in KEPCO System." IEEE Access 9, no. : 1-1.
System strength is an important concept in the integration of renewable energy sources (RESs). However, evaluating system strength is becoming more ambiguous due to the interaction of RESs. This paper proposes a novel scheme to define the actual interaction boundaries of RESs using the power flow tracing strategy. Based on the proposed method, the interaction boundaries of RESs were identified at the southwest side of Korea Electric Power Corporation (KEPCO) systems. The test results show that the proposed approach always provides the identical interaction boundaries of RESs in KEPCO systems, compared to the Electric Reliability Council of Texas (ERCOT) method. The consistent boundaries could be a guideline for power-system planners to assess more accurate system strength, considering the actual interactions of the RESs.
Namki Choi; Byongjun Lee; Dohyuk Kim; Suchul Nam. Interaction Boundary Determination of Renewable Energy Sources to Estimate System Strength Using the Power Flow Tracing Strategy. Sustainability 2021, 13, 1569 .
AMA StyleNamki Choi, Byongjun Lee, Dohyuk Kim, Suchul Nam. Interaction Boundary Determination of Renewable Energy Sources to Estimate System Strength Using the Power Flow Tracing Strategy. Sustainability. 2021; 13 (3):1569.
Chicago/Turabian StyleNamki Choi; Byongjun Lee; Dohyuk Kim; Suchul Nam. 2021. "Interaction Boundary Determination of Renewable Energy Sources to Estimate System Strength Using the Power Flow Tracing Strategy." Sustainability 13, no. 3: 1569.
The global increase in the use of solar photovoltaics and wind turbines has led to a rapid increase in the penetration level of inverter-based distributed generators (IBDGs). Until recently, the operation modes of IBDGs under abnormal power system conditions were not a major concern owing to the small number of IBDGs used in power systems. However, several events have indicated that the momentary cessation (MC) mode of an IBDG can eventually deteriorate the stability of power systems. Among the various parameters that define the MC mode, the direct impact of the MC recovery ramp rate on the transient stability of the power system has been addressed by computing the stability margin based on a single machine equivalent method. Furthermore, this paper introduces the critical momentary cessation recovery ramp rate for a specific system, which can be used as an important index in the planning of an IBDG installation. Case studies on modified IEEE 39 bus system and Korean power system were conducted to validate the effectiveness of the proposed method.
Sungwoo Kang; Heewon Shin; Gilsoo Jang; Byongjun Lee. Impact analysis of recovery ramp rate after momentary cessation in inverter‐based distributed generators on power system transient stability. IET Generation, Transmission & Distribution 2020, 15, 24 -33.
AMA StyleSungwoo Kang, Heewon Shin, Gilsoo Jang, Byongjun Lee. Impact analysis of recovery ramp rate after momentary cessation in inverter‐based distributed generators on power system transient stability. IET Generation, Transmission & Distribution. 2020; 15 (1):24-33.
Chicago/Turabian StyleSungwoo Kang; Heewon Shin; Gilsoo Jang; Byongjun Lee. 2020. "Impact analysis of recovery ramp rate after momentary cessation in inverter‐based distributed generators on power system transient stability." IET Generation, Transmission & Distribution 15, no. 1: 24-33.
Renewable energy curtailment often occurs to accommodate large amounts of renewable energy sources in power systems while maintaining system stability and reliability. Widely known methods, such as new transmission line construction, the introduction of demand-side resources, and the reduction of conventional generator output, can minimize the occurrence of curtailment; however, there are difficulties in introducing them because of social and economic problems. For these problems, the Jeju power system adopted a battery energy storage system (BESS) resource to mitigate the curtailment and secure frequency stability with the high penetration of renewable energy. The small-size Jeju island power system is operated with reliability must-run (RMR) units and high-voltage direct current (HVDC) lines connected to the mainland. Since the number of RMR units contributes to frequency stability by providing inertia, reducing the number of operating units for curtailment mitigation is difficult. Therefore, in this paper, based on the current “Carbon-Free island” policy and operation plan of the Jeju power system, we proposed a BESS for reducing the number of RMR units, observe the effect of reducing curtailment using the BESS, and suggest a practical operation plan to reduce the number of RMR units under conditions that secure frequency stability.
Changgun Lee; Seunghyuk Im; Jaeyeop Jung; Byongjun Lee. BESS Deployment Strategy in Jeju Carbon-Free Islands for Reducing Renewable Energy Curtailment. Energies 2020, 13, 6082 .
AMA StyleChanggun Lee, Seunghyuk Im, Jaeyeop Jung, Byongjun Lee. BESS Deployment Strategy in Jeju Carbon-Free Islands for Reducing Renewable Energy Curtailment. Energies. 2020; 13 (22):6082.
Chicago/Turabian StyleChanggun Lee; Seunghyuk Im; Jaeyeop Jung; Byongjun Lee. 2020. "BESS Deployment Strategy in Jeju Carbon-Free Islands for Reducing Renewable Energy Curtailment." Energies 13, no. 22: 6082.
This paper investigates systemwide short-term voltage stability concerns of power systems due to the multiple parametric uncertainties in the dynamic load model. The impact of regional load model uncertainty can be widespread and may mislead the whole system analysis and subsequent measures, if not properly addressed. This research discloses that the systemwide impact is related to the voltage weak areas through voltage stability modal analysis, and suggests that the impact of uncertain parameters needs to be assessed from a system's perspective, which has rarely been done in the existing practices. We thus present a three-step methodology for evaluating the systemwide uncertainty impacts: Firstly, it screens possible trajectories of all buses. The second step verifies whether the screened trajectories comply with the defined criteria, and determines the necessity of the final step. The final detailed analysis is conducted for those selected scenarios. Comprehensive studies for both the IEEE test and real Korea power systems consistently confirm the observations and demonstrate the efficacy and validity of the proposed method.
Jae-Kyeong Kim; Byongjun Lee; Jin Ma; Gregor Verbic; Suchul Nam; Kyeon Hur. Understanding and Evaluating Systemwide Impacts of Uncertain Parameters in the Dynamic Load Model on Short-term Voltage Stability. IEEE Transactions on Power Systems 2020, PP, 1 -1.
AMA StyleJae-Kyeong Kim, Byongjun Lee, Jin Ma, Gregor Verbic, Suchul Nam, Kyeon Hur. Understanding and Evaluating Systemwide Impacts of Uncertain Parameters in the Dynamic Load Model on Short-term Voltage Stability. IEEE Transactions on Power Systems. 2020; PP (99):1-1.
Chicago/Turabian StyleJae-Kyeong Kim; Byongjun Lee; Jin Ma; Gregor Verbic; Suchul Nam; Kyeon Hur. 2020. "Understanding and Evaluating Systemwide Impacts of Uncertain Parameters in the Dynamic Load Model on Short-term Voltage Stability." IEEE Transactions on Power Systems PP, no. 99: 1-1.
Reactive power reserves are important for grid stability and have a variety patterns depending on fault location as power systems become larger and complex. This paper presents the clustered effective reactive reserve (CEQR), an indicator that is suitable for identifying the risk of dynamic voltage stabitlity in terms of power system operation. This indicator provides the following features: i) It calculate the realistic reactive reserve to recognize dynamically changing system conditions; ii)it derive clustered areas to identify valid regions for system control. The proposed method uses the sensitivity between dynamic reactive resources or load buses and a particular bus to obtain the correlation. And since this indicator is calculated using only the system topology, current and maximum outputs of the generators, there is less computational burden. This study verified the features of clustered effective reactive reserve(CEQR) by analyzing the practicable dynamic voltage collapse scenarios in the Korean electric power(KEPCO) system. In addition, as a countermeasure against the dynamic voltage collapse, the control performance of blocking tap changer scheme using the proposed indicator is described.
BoHyun Park; Seunghyuk Im; Dohyuk Kim; Byongjun Lee. Clustered Effective Reactive Reserve to Secure Dynamic Voltage Stability in Power System Operation. IEEE Transactions on Power Systems 2020, 36, 1183 -1192.
AMA StyleBoHyun Park, Seunghyuk Im, Dohyuk Kim, Byongjun Lee. Clustered Effective Reactive Reserve to Secure Dynamic Voltage Stability in Power System Operation. IEEE Transactions on Power Systems. 2020; 36 (2):1183-1192.
Chicago/Turabian StyleBoHyun Park; Seunghyuk Im; Dohyuk Kim; Byongjun Lee. 2020. "Clustered Effective Reactive Reserve to Secure Dynamic Voltage Stability in Power System Operation." IEEE Transactions on Power Systems 36, no. 2: 1183-1192.
This study presents a new wide-area voltage stability monitoring method using synchronised phasor measurements. The salient features of the proposed index are the following: (i) It ensures constancy, which is the ability to maintain the same scale even if the system changes. (ii) It is pseudo-linear with respect to the power system stability level, which enhances intuitiveness for real-time operation. Accordingly, stability can be uniformly compared in various situations, and thus, the index can be used as a solid criterion or threshold point for system operation. A verification study of the proposed index with regard to constancy is carried out using Korean power system operation data. Furthermore, an implementation of the proposed method for the Korean wide-area monitoring system is presented, and it is demonstrated that the proposed index detects event more clearly than previous stability index through an actual event measured using phasor measurement units.
Jaeyeop Jung; Hwanhee Cho; BoHyun Park; Suchul Nam; Kyeon Hur; Byongjun Lee. Enhancement of linearity and constancy of PMU‐based voltage stability index: application to a Korean wide‐area monitoring system. IET Generation, Transmission & Distribution 2020, 14, 3357 -3364.
AMA StyleJaeyeop Jung, Hwanhee Cho, BoHyun Park, Suchul Nam, Kyeon Hur, Byongjun Lee. Enhancement of linearity and constancy of PMU‐based voltage stability index: application to a Korean wide‐area monitoring system. IET Generation, Transmission & Distribution. 2020; 14 (17):3357-3364.
Chicago/Turabian StyleJaeyeop Jung; Hwanhee Cho; BoHyun Park; Suchul Nam; Kyeon Hur; Byongjun Lee. 2020. "Enhancement of linearity and constancy of PMU‐based voltage stability index: application to a Korean wide‐area monitoring system." IET Generation, Transmission & Distribution 14, no. 17: 3357-3364.
The penetration of renewable energy sources (RESs) equipped with inverter-based control systems such as wind and solar plants are increasing. Therefore, the speed of the voltage controllers associated with inverter-based resources (IBRs) has a substantial impact on the stability of the interconnected grid. System strength evaluation is one of the important concerns in the integration of IBRs, and this strength is often evaluated in terms of the short circuit ratio (SCR) index. When IBRs are installed in an adjacent location, system strength can be weaker than evaluation by SCR. This study proposes an inverter interaction level short circuit ratio (IILSCR) method by tracing IBRs output flow. The IILSCR can accurately estimate system strength, wherein IBRs are connected in adjacent spots, by reflecting the interaction level between IBRs. The study also demonstrates the efficiency of IILSCR by applying this method to Institute of Electrical and Electronics Engineers (IEEE) 39 bus test system and future Korea power systems.
Dohyuk Kim; Hwanhee Cho; BoHyun Park; Byongjun Lee. Evaluating Influence of Inverter-based Resources on System Strength Considering Inverter Interaction Level. Sustainability 2020, 12, 3469 .
AMA StyleDohyuk Kim, Hwanhee Cho, BoHyun Park, Byongjun Lee. Evaluating Influence of Inverter-based Resources on System Strength Considering Inverter Interaction Level. Sustainability. 2020; 12 (8):3469.
Chicago/Turabian StyleDohyuk Kim; Hwanhee Cho; BoHyun Park; Byongjun Lee. 2020. "Evaluating Influence of Inverter-based Resources on System Strength Considering Inverter Interaction Level." Sustainability 12, no. 8: 3469.
This paper proposes a method to adjust the gain control algorithm in a STATCOM controller. The salient features of this method are the automatic detection of subsynchronous resonance in power systems and the automatic gain tuning of the STATCOM controller to mitigate subsynchronous resonance. The algorithm uses controller input to produce a delay-embedded time-series plane and is implemented in the STATCOM controller to detect the time of local oscillation. A new gain value is calculated in the radius of the trajectory extracted from the geometric map using phase space reconstruction and the mitigation of voltage and reactive power oscillation is confirmed by electromagnetic transient analysis.
Hyeokjin Noh; Hwanhee Cho; Seungryul Lee; Byongjun Lee. STATCOM with SSR damping controller using geometric extraction on phase space reconstruction method. International Journal of Electrical Power & Energy Systems 2020, 120, 106017 .
AMA StyleHyeokjin Noh, Hwanhee Cho, Seungryul Lee, Byongjun Lee. STATCOM with SSR damping controller using geometric extraction on phase space reconstruction method. International Journal of Electrical Power & Energy Systems. 2020; 120 ():106017.
Chicago/Turabian StyleHyeokjin Noh; Hwanhee Cho; Seungryul Lee; Byongjun Lee. 2020. "STATCOM with SSR damping controller using geometric extraction on phase space reconstruction method." International Journal of Electrical Power & Energy Systems 120, no. : 106017.
This study presents a robust optimization model to secure flexibility under a high penetration of renewable energy systems in a future grid. An increase in renewable energy into a power system causes difficulties and complexities with regard to power system planning and operation owing to an increase in uncertainty. This trend can create an issue in the flexibility of a power system under a high penetration of renewable energy. To acquire sufficient flexibility, numerous flexible resources such as conventional generators with a ramping capability, energy storage systems and demand response program should be procured. Herein, we propose estimating the flexible resource capacity required to prevent a flexibility deficit when considering multiple uncertainties such as the effective capacity and 1-min power fluctuation rate of the renewable energy systems. To solve this problem, including uncertainties, through an optimization technique, we adopt a robust optimization to deal with uncertainty by constructing an uncertainty set and provide a robust solution considering the worst case within such a set. The robust optimization model was tested using data from the Korean electric power system for the year 2030. In addition, the results from a robust optimization are compared with the results from a deterministic approach.
Jinwoo Jeong; Byongjun Lee. A framework for estimating flexible resources according to future Korean renewables scenario: Robust optimization approach considering multiple uncertainties. International Journal of Electrical Power & Energy Systems 2019, 118, 105728 .
AMA StyleJinwoo Jeong, Byongjun Lee. A framework for estimating flexible resources according to future Korean renewables scenario: Robust optimization approach considering multiple uncertainties. International Journal of Electrical Power & Energy Systems. 2019; 118 ():105728.
Chicago/Turabian StyleJinwoo Jeong; Byongjun Lee. 2019. "A framework for estimating flexible resources according to future Korean renewables scenario: Robust optimization approach considering multiple uncertainties." International Journal of Electrical Power & Energy Systems 118, no. : 105728.
The responses of an inverter-based distributed generator (IBDG) to abnormal voltage and frequency are different from those of a conventional generator because of the inverter's operating modes. In particular, although the momentary cessation (MC) mode is essential to protecting the distribution system, the MC mode can affect the power system transient stability by temporarily ceasing significant amounts of IBDG generation. To mitigate these negative effects, this study analyzed the impacts of MC capability on the power system transient stability. First, the transient stability was analyzed in relation to MC capability using the single-machine equivalent (SIME) method. A critical MC operating point (CMCOP) was then proposed to assess the severity of a transient impact and to secure the transient stability under the contingency conditions. A case study based on the Korean power system validated the feasibility and effectiveness of the proposed method.
Heewon Shin; Jaeyeop Jung; Seungchan Oh; Kyeon Hur; Kenji Iba; Byongjun Lee. Evaluating the Influence of Momentary Cessation Mode in Inverter-Based Distributed Generators on Power System Transient Stability. IEEE Transactions on Power Systems 2019, 35, 1618 -1626.
AMA StyleHeewon Shin, Jaeyeop Jung, Seungchan Oh, Kyeon Hur, Kenji Iba, Byongjun Lee. Evaluating the Influence of Momentary Cessation Mode in Inverter-Based Distributed Generators on Power System Transient Stability. IEEE Transactions on Power Systems. 2019; 35 (2):1618-1626.
Chicago/Turabian StyleHeewon Shin; Jaeyeop Jung; Seungchan Oh; Kyeon Hur; Kenji Iba; Byongjun Lee. 2019. "Evaluating the Influence of Momentary Cessation Mode in Inverter-Based Distributed Generators on Power System Transient Stability." IEEE Transactions on Power Systems 35, no. 2: 1618-1626.
Distributed energy resource (DER) has different power generation characteristics from conventional generators because wind turbine generators and photovoltaic generators are connected to grid through inverters. Therefore, transient stability analysis in power system with inverter-based DER should be conducted considering inverter characteristics because the inverter‘s operating modes can affect power system stability. This paper presents the definition of critical momentary cessation voltage for securing power system stability and estimates power system regional dependency of DER. The effectiveness and feasibility of the critical momentary cessation voltage are demonstrated in Korean power system. Transient stability assessment is used to verify the results.
Heewon Shin; Byongjun Lee; Kenji Iba. Power System Regional Dependency of Distributed Energy Resources: Utilizing the Momentary Cessation Capability. IFAC-PapersOnLine 2019, 52, 1 -5.
AMA StyleHeewon Shin, Byongjun Lee, Kenji Iba. Power System Regional Dependency of Distributed Energy Resources: Utilizing the Momentary Cessation Capability. IFAC-PapersOnLine. 2019; 52 (4):1-5.
Chicago/Turabian StyleHeewon Shin; Byongjun Lee; Kenji Iba. 2019. "Power System Regional Dependency of Distributed Energy Resources: Utilizing the Momentary Cessation Capability." IFAC-PapersOnLine 52, no. 4: 1-5.
Measurement-based technology has been developed in the area of power transmission systems with phasor measurement units (PMU). Using high-resolution PMU data, the oscillatory behavior of power systems from general electromagnetic oscillations to sub-synchronous resonances can be observed. Studying oscillations in power systems is important to obtain information about the orbital stability of the system. Floquet multipliers calculation is based on a mathematical model to determine the orbital stability of a system with the existence of stable or unstable periodic solutions. In this paper, we have developed a model-free method to estimate Floquet multipliers using time series data. A comparative study between calculated and estimated Floquet multipliers has been performed to validate the proposed method. The results are provided for a sample three-bus power system network and the system integrated with a doubly fed induction generator.
Namki Choi; Hwanhee Cho; Byongjun Lee. Development of Floquet Multiplier Estimator to Determine Nonlinear Oscillatory Behavior in Power System Data Measurement. Energies 2019, 12, 1824 .
AMA StyleNamki Choi, Hwanhee Cho, Byongjun Lee. Development of Floquet Multiplier Estimator to Determine Nonlinear Oscillatory Behavior in Power System Data Measurement. Energies. 2019; 12 (10):1824.
Chicago/Turabian StyleNamki Choi; Hwanhee Cho; Byongjun Lee. 2019. "Development of Floquet Multiplier Estimator to Determine Nonlinear Oscillatory Behavior in Power System Data Measurement." Energies 12, no. 10: 1824.
This study analyzed the impact of varying the momentary cessation (MC) voltage level on the short circuit current of inverter-based resources (IBRs). To analyze the impact of the IBR MC function on the short circuit current, this paper proposes an advanced IBR model for fault current calculation to reflect its fault characteristics and a scheme for analyzing the influence of MC on the short circuit current. Based on the proposed methods, the authors conducted case studies using planning data from the Korea Electric Power Corporation (KEPCO). The influence of MC was investigated on the IBRs located at the southwest side of the KEPCO systems by screening the fault currents while varying the MC voltage. This paper demonstrates that the minimum MC voltage level needed for the fault current not to exceed the circuit breaker (CB) capacity can be proposed through analyzing the impact of MC voltage level on the short circuit current. The test results based on the proposed scheme showed that the short circuit current to power systems could not violate CB capacity if IBRs adjusted the MC voltage level higher than the lowest MC voltage level.
Namki Choi; BoHyun Park; Hwanhee Cho; Byongjun Lee. Impact of Momentary Cessation Voltage Level in Inverter-Based Resources on Increasing the Short Circuit Current. Sustainability 2019, 11, 1153 .
AMA StyleNamki Choi, BoHyun Park, Hwanhee Cho, Byongjun Lee. Impact of Momentary Cessation Voltage Level in Inverter-Based Resources on Increasing the Short Circuit Current. Sustainability. 2019; 11 (4):1153.
Chicago/Turabian StyleNamki Choi; BoHyun Park; Hwanhee Cho; Byongjun Lee. 2019. "Impact of Momentary Cessation Voltage Level in Inverter-Based Resources on Increasing the Short Circuit Current." Sustainability 11, no. 4: 1153.
An energy paradigm shift has rapidly occurred around the globe. One change has been an increase in the penetration of sustainable energy. However, this can affect the reliability of power systems by increasing variability and uncertainty from the use of renewable resources. To improve the reliability of an energy supply, a power system must have a sufficient amount of flexible resources to prevent a flexibility deficit. This paper proposes a countermeasure for protecting nonnegative flexibility under high-level penetration of renewable energy with robust optimization. The proposed method is divided into three steps: (i) constructing an uncertainty set with the capacity factor of renewable energy, (ii) searching for the initial point of a flexibility deficit, and (iii) calculating the capacity of the energy storage system to avoid such a deficit. In this study, robust optimization is applied to consider the uncertainty of renewable energy, and the results are compared between deterministic and robust approaches. The proposed method is demonstrated on a power system in the Republic of Korea.
Jinwoo Jeong; Heewon Shin; Hwachang Song; Byongjun Lee. A Countermeasure for Preventing Flexibility Deficit under High-Level Penetration of Renewable Energies: A Robust Optimization Approach. Sustainability 2018, 10, 4159 .
AMA StyleJinwoo Jeong, Heewon Shin, Hwachang Song, Byongjun Lee. A Countermeasure for Preventing Flexibility Deficit under High-Level Penetration of Renewable Energies: A Robust Optimization Approach. Sustainability. 2018; 10 (11):4159.
Chicago/Turabian StyleJinwoo Jeong; Heewon Shin; Hwachang Song; Byongjun Lee. 2018. "A Countermeasure for Preventing Flexibility Deficit under High-Level Penetration of Renewable Energies: A Robust Optimization Approach." Sustainability 10, no. 11: 4159.
Efforts to reduce greenhouse gas emissions constitute a worldwide trend. According to this trend, there are many plans in place for the replacement of conventional electric power plants operating using fossil fuels with renewable energy sources (RESs). Owing to current needs to expand the RES penetration in accordance to a new National power system plan, the importance of RESs is increasing. The RES penetration imposes various impacts on the power system, including transient stability. Furthermore, the fact that they are distributed at multiple locations in the power system is also a factor which makes the transient impact analysis of RESs difficult. In this study, the transient impacts attributed to the penetration of RESs are analyzed and compared with the conventional Korean electric power system. To confirm the impact of the penetration of RESs on transient stability, the effect was analyzed based on a single machine equivalent (SIME) configuration. Simulations were conducted in accordance to the Korean power system by considering the anticipated RES penetration in 2030. The impact of RES on transient stability was provided by a change in CCT by increasing of the RES penetration.
Seungchan Oh; Heewon Shin; Hwanhee Cho; Byongjun Lee. Transient Impact Analysis of High Renewable Energy Sources Penetration According to the Future Korean Power Grid Scenario. Sustainability 2018, 10, 4140 .
AMA StyleSeungchan Oh, Heewon Shin, Hwanhee Cho, Byongjun Lee. Transient Impact Analysis of High Renewable Energy Sources Penetration According to the Future Korean Power Grid Scenario. Sustainability. 2018; 10 (11):4140.
Chicago/Turabian StyleSeungchan Oh; Heewon Shin; Hwanhee Cho; Byongjun Lee. 2018. "Transient Impact Analysis of High Renewable Energy Sources Penetration According to the Future Korean Power Grid Scenario." Sustainability 10, no. 11: 4140.
This study proposes a time-series analysis approach and a non-linear dynamics originated method to detect sub-synchronous oscillation in power systems. Mathematical expressions of the fundamental instantaneous signal and sample discrete signal of peak values are derived to examine the phenomenon of interaction between power system components. The results of the circulating trajectory are shown in a two-dimensional map of the calculated root-mean-square value and estimated Floquet multiplier when two signals of different modes are mixed. Without applying a digital filter or frequency decomposition, non-linear oscillation detection is possible by monitoring a non-linear oscillatory index based on the maximum Lyapunov exponent.
Hwanhee Cho; Seungchan Oh; Suchul Nam; Byongjun Lee. Non‐linear dynamics based sub‐synchronous resonance index by using power system measurement data. IET Generation, Transmission & Distribution 2018, 12, 4026 -4033.
AMA StyleHwanhee Cho, Seungchan Oh, Suchul Nam, Byongjun Lee. Non‐linear dynamics based sub‐synchronous resonance index by using power system measurement data. IET Generation, Transmission & Distribution. 2018; 12 (17):4026-4033.
Chicago/Turabian StyleHwanhee Cho; Seungchan Oh; Suchul Nam; Byongjun Lee. 2018. "Non‐linear dynamics based sub‐synchronous resonance index by using power system measurement data." IET Generation, Transmission & Distribution 12, no. 17: 4026-4033.
Although electric railway systems have gone through many technological innovations in their electrical, mechanical and structural engineering since the energy paradigm conversion to electrical energy, the conventional feeding system based on the catenary contact is still being applied. In order to solve the problems of the contact-based feeding system that arise and to build up the energy-sustainable electric railway system simultaneously, this paper considers the wireless railway train (WRT), which is fed by storages mounted on the board without catenary contact during driving and charged at a platform during a stop. In order to maximize the energy improvement of WRTs’ operation, the optimal power and storage capacity estimation method considering the increased weight of the additional storage devices is proposed. Through case studies of the electrical and topographical conditions of the actual operating railway route, compared with the electrical performance of the existing railway trains, it is verified that the application of WRTs leads to facility capacity margin enlargement through the peak power reduction, and cost-effectiveness improvement through the reduction of catenary loss and driving energy.
Jaewon Kim; Joorak Kim; Changmu Lee; Gildong Kim; Hansang Lee; Byongjun Lee. Optimal Capacity Estimation Method of the Energy Storage Mounted on a Wireless Railway Train for Energy-Sustainable Transportation. Energies 2018, 11, 986 .
AMA StyleJaewon Kim, Joorak Kim, Changmu Lee, Gildong Kim, Hansang Lee, Byongjun Lee. Optimal Capacity Estimation Method of the Energy Storage Mounted on a Wireless Railway Train for Energy-Sustainable Transportation. Energies. 2018; 11 (4):986.
Chicago/Turabian StyleJaewon Kim; Joorak Kim; Changmu Lee; Gildong Kim; Hansang Lee; Byongjun Lee. 2018. "Optimal Capacity Estimation Method of the Energy Storage Mounted on a Wireless Railway Train for Energy-Sustainable Transportation." Energies 11, no. 4: 986.
A definition of Load Loss Coefficient (LLC) is given in this study along with the power loss tracing algorithm. As LLC indicates the effect of load on power transmission loss, its calculation is performed based on the Bialek’s power tracing method, where gross and net flows are being considered, to determine the power loss in a system during power transmission.
Moonsung Bae; Byongjun Lee. Load Loss Coefficient and Power Loss Tracing in Power Systems. Lecture Notes in Electrical Engineering 2017, 240 -247.
AMA StyleMoonsung Bae, Byongjun Lee. Load Loss Coefficient and Power Loss Tracing in Power Systems. Lecture Notes in Electrical Engineering. 2017; ():240-247.
Chicago/Turabian StyleMoonsung Bae; Byongjun Lee. 2017. "Load Loss Coefficient and Power Loss Tracing in Power Systems." Lecture Notes in Electrical Engineering , no. : 240-247.
When it is necessary to adjust the power flow over a certain bus, the method that best uses given conditions to efficiently adjust power flow is essential. There are several ways to control the power flow on transmission lines by adjusting the power generations but the method that controls the flow by rescheduling the generation is not adequate for use as it is not easy to carry out power flow adjustment on a particular line or it is not clear which power generator’s power generation capacity should be adjusted as the active power has little regional constraints. Thus, a method that can cope with these problems is required. Therefore, a method that trace the origin of power flow over a particular power line by using the power flow tracing technique to control power generation level and eventually adjust power flow has been proposed in this study.
Moonsung Bae; Byongjun Lee. A Power Generation Rescheduling Method Under Power Flow Constraints Using Power Flow Tracing. Lecture Notes in Electrical Engineering 2017, 248 -252.
AMA StyleMoonsung Bae, Byongjun Lee. A Power Generation Rescheduling Method Under Power Flow Constraints Using Power Flow Tracing. Lecture Notes in Electrical Engineering. 2017; ():248-252.
Chicago/Turabian StyleMoonsung Bae; Byongjun Lee. 2017. "A Power Generation Rescheduling Method Under Power Flow Constraints Using Power Flow Tracing." Lecture Notes in Electrical Engineering , no. : 248-252.