A rapid diagnosis technology of short circuit fault in DC microgrid

Wan, Qingzhu; Zheng, Shuai; Shi, Chenlu

doi:10.1016/j.ijepes.2022.108878

Cited by 6 publications

(3 citation statements)

References 27 publications

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“…Figure 1 is a schematic diagram of a resistive balanced bridge, R1, R2: equal value of the balanced resistance, XJJ is a signal relay, R+ is the positive insulation resistance, R-is the negative insulation resistance [6] . Signal injection method is when there is a ground fault to the DC system injected signals, through the branch circuit current sensor to collect each circuit current flow to determine the grounded branch circuit, usually can be divided into low-frequency signal injection method and dual-frequency signal injection method two.…”

Section: Figure 1 Resistor Balanced Bridge Schematicmentioning

confidence: 99%

Ground fault detection in substation DC system based on improved differential current method

Li,

Zhang,

Shen

et al. 2024

J. Phys.: Conf. Ser.

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DC system is the main electrical equipment and control signal system in the substation, and its stability and reliability are directly related to whether the power system can operate safely. This paper firstly introduces the common methods of insulation detection of DC power system in substation and its advantages and disadvantages, and proposes the differential current method based on unbalanced bridge, i.e., using the combination of unbalanced bridge and leakage current sensor to detect the insulation condition of DC system, which makes up for the defects of the traditional differential current method that can only detect the faults of simple branch circuits, and realizes the detection of multi-branch grounding under complex situations. Finally, the feasibility of this method is verified by building a simulation model through simulink.

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Section: Figure 1 Resistor Balanced Bridge Schematicmentioning

confidence: 99%

Ground fault detection in substation DC system based on improved differential current method

Li,

Zhang,

Shen

et al. 2024

J. Phys.: Conf. Ser.

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“…The existing literature review includes numerous protection methods for DC distribution networks. A quick DC microgrid fault diagnosis technique was suggested in [8], involving mathematical modeling and multi-objective optimization for fault identification/localization, while fault location is calculated by means of a genetic algorithm. Likewise, the authors in [9] offered a high-speed protection method employing mathematical morphology (MM).…”

Section: B Literature Reviewmentioning

confidence: 99%

Enhanced Fault Detection and Localization Strategy for High-Speed Protection in Medium-Voltage DC Distribution Networks Using Extended Kalman Filtering Algorithm

Larik,

Li,

2024

IEEE Access

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Conventional strategies are not effective in addressing the complex protection challenges in medium-voltage DC distribution networks (MVDCDN). The main challenge in MVDCDN is the high-rising DC fault current, requiring a robust and fast protection strategy. This paper proposes the use of an Extended Kalman filter (EKF) to detect various types of DC faults using only the current signal in the MVDCDN. In the first stage, current signals from the positive and negative poles corresponding bus are obtained. The EKF is then applied to the measured DC-current signals to generate two fault detection indices. The first index is the cumulative residuals (CR), calculated using the EKF iterative differencing process with updated current estimated state and noisy measurement. The second index is the modified DC version of total harmonic distortion, known as DC distortion factor (DCDF). The fault classification/zone identification (FCZI) unit is activated if changes in CR and DCDF are detected within the observation window of the relay. In the second stage, the FCZI unit calculates the Extended Kalman filter-based predicted energy (EKFBPE) for the faulty DC line section at both ends. The polarity of EKFBPE is used for fault classification and localization decisions. The proposed protection strategy requires low-band wireless communication capability in the smart grid. Extensive simulations using MATLAB ®Simulink 2022b are conducted on a ±2.5 kV MVDCDN with three feeders, considering various fault scenarios. The results demonstrate that the proposed scheme achieves 99.9% accuracy, under radial, looped, and meshed topology and is highly resilient to different types of faults with time of operation 1 msec. The scalability of proposed method and its effectiveness in handling higher voltage levels and associated fault uncertainty will investigate in future research.

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“…Previous references have discussed various challenges, including frequency control, power quality, reactive power support, fault analysis, electricity market penetration, and environmental concerns. Wan et al [8], proposed a rapid diagnosis technology for short-circuit faults in a DC microgrid, focusing on fault classification and location. Similarly, Nahas et al [9], presented a fault analysis of a DC microgrid, considering the representation of its components.…”

Section: Introductionmentioning

confidence: 99%

Investigation of Fault Analysis for Renewable Energy Microgrid

Abbood,

Habbi,

Zohdy

2023

ETJ

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The impact of all types of faults on system operation (islanded or grid-connected) was explored.• The increment of the value of THD by 92% to 93.5% from its normal value indicates a fault occurrence. • The value of the fault current specifies the type of protection system (fast or slow) in microgrid systems.This paper investigates the behavior of four bus grid-connected systems during different types of faults. The microgrid comprises a utility grid, a solar PV energy system, a diesel generator, and a load. Symmetrical and unsymmetrical faults at the microgrid distribution network were studied. These faults were applied at the solar PV bus under constant irradiance and temperature. The active and reactive power from the solar PV was synchronized based on the maximum power point tracking (MPPT) solar inverter. The total harmonic distortion (THD) for the load current response was also measured for each symmetrical and unsymmetrical fault. A protection system was strategically located based on specific constraints, such as fault location and detection. The simulation results were categorized into two scenarios: normal and abnormal conditions during faults in the distribution lines. The obtained results revealed significant differences in fault currents depending on the type of fault, which consequently influenced the selection of the appropriate protection system. The operation mode of the microgrid, whether in isolated or microgrid-connected mode, varied according to the fault type. Furthermore, the THD value of the load current exhibited a substantial increase during fault conditions. MATLAB/Simulink was utilized for conducting all the simulations.

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A rapid diagnosis technology of short circuit fault in DC microgrid

Cited by 6 publications

References 27 publications

Ground fault detection in substation DC system based on improved differential current method

Ground fault detection in substation DC system based on improved differential current method

Enhanced Fault Detection and Localization Strategy for High-Speed Protection in Medium-Voltage DC Distribution Networks Using Extended Kalman Filtering Algorithm

Investigation of Fault Analysis for Renewable Energy Microgrid

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