- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Short-term Voltage Stability Enhancement in Residential Grid with High Penetration of Rooftop PV units
摘要： Short-term voltage instability (STVI) imposes a severe threat to modern distribution networks (DNs) where a large number of intermittent distributed generator (DG) units, like rooftop photovoltaic (PV), is being integrated. Consequently, most of the international standards have been revised by incorporating the requirement of dynamic voltage support (DVS) through DG units, which is a promising approach to alleviate the STVI. In this paper, a novel DVS strategy is proposed to improve the short-term voltage stability (STVS) in residential grids. In comparison with other DVS strategies, the proposed DVS scheme maximizes the active power support from PV units following a contingency utilizing maximum allowable current of the PV inverters. Moreover, the inverter design margin is taken into account in designing the proposed scheme to limit the injected grid current within maximum allowable inverter current. The impact of inverter design margin on the STVS is explained, and the effectiveness of the proposed strategy compared with conventional DVS is demonstrated. The feasibility of the DVS control strategies in practical application is studied. Several case studies are carried out on benchmark IEEE 4 bus and IEEE 13 node test feeder systems, and finally on a ring-type DN. The results show that the proposed DVS scheme is feasible, and achieved superior performance compared to the other strategies. Furthermore, it has been shown that implementation of the proposed DVS scheme can avoid the installation of an expensive 1200 kVA D-STATCOM for STVS improvement in the target system.
关键词： Distributed generators,fault induced delayed voltage recovery,low voltage ride-through,dynamic voltage support,short-term voltage stability,distribution system
更新于2025-09-23 15:21:01
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[IEEE 2020 IEEE International Conference on Power Electronics, Smart Grid and Renewable Energy (PESGRE) - Cochin, India (2020.1.2-2020.1.4)] 2020 IEEE International Conference on Power Electronics, Smart Grid and Renewable Energy (PESGRE2020) - Analysis of Low Voltage Ride Through Techniques for Grid-Connected Photovoltaic Systems
摘要： This paper presents a comparative analysis of different low voltage ride though strategies proposed for operation of a grid connected two stage photovoltaic system under low voltages. The existing grid codes mandate that, under the presence of low voltages, a distributed energy resource (DER) must stay connected to the grid for a minimum amount of time. This results in abnormally high currents though the inverter of a PV system, which can potentially damage the semiconductor switches. To avoid this, low voltage ride through techniques are proposed in the literature to ensure that the DER stays connected to the grid. Traditionally, the performance of LVRT techniques is evaluated by assuming an ideal voltage dip at the point of common coupling. In this work, comparative evaluation of different LVRT techniques is carried out on the CERTS testbed with an objective to highlight the impact of network transients on their performance.
关键词： active power,reactive power,inverter.,Low voltage ride through,DC-link voltage
更新于2025-09-23 15:21:01
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Transient Stability Enhancement of Wind Farms using Photovoltaic Solar Plant as STATCOM
摘要： The aim of this study is to investigate the improvement of the performances and transient stability of grid connected Squirrel Cage Induction Generator based on Wind Farm (SCIG-WF) by using a new coordinated control between Grid Side Converter (GSC) of the Doubly Fed Induction Generator (DFIG) and photovoltaic solar plant converter (PV-SPC) as STATCOM. Thereby, the reactive power required by the SCIG-WF can be supplied either by the DFIGs (during normal condition) and with the PV-STATCOM during grid disturbances. This control strategy can fulfill the grid codes requirement such low voltage ride through capability by ensuring a no uninterrupted operation of the wind farm. The proposed control scheme is simulated by means of MATLAB/Simulink platform, based on a detailed system model. Through the simulated results, we can conclude that the proposed control for PV-SPC to operate as STATCOM is validated and the performances of the system are improved during normal and transient conditions.
关键词： system stability,squirrel cage induction generator,voltage regulation,low voltage ride through,power quality,Doubly-fed induction generator
更新于2025-09-16 10:30:52
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[IEEE 2019 International Conference on Power Electronics, Control and Automation (ICPECA) - New Delhi, India (2019.11.16-2019.11.17)] 2019 International Conference on Power Electronics, Control and Automation (ICPECA) - Droop based Low voltage ride through implementation for grid integrated photovoltaic system
摘要： This paper signi?es the development of an ef?cient and cost-effective control scheme for operation of grid integrated photovoltaic (PV) system under low voltage ride through (LVRT) condition. During LVRT If the PV system was to disconnect from the grid, the disconnection further aggravates the situation by causing larger disturbance than what was caused by the fault. To stabilize the system and prevent the ?ow of over current during LVRT it is necessary to control the reactive power injection in the system. The proposed scheme balances the active power though proportional gain regulation of plug in controller. Compared to the conventional LVRT method, this method is more cost effective. A normal maximum power point tracking (MPPT) scheme is implemented during normal operation. But in case of fault condition, an extra proportional controller is added to assist the droop characteristics of photovoltaic power voltage curve and attain system stability. Simulation has been performed on a grid integrated PV system of 4kW and LVRT conditions are tested. It is observed that the response of controller is fast and seamless during transition mode.
关键词： Active power control,Grid integrated photovoltaic(PV) system,Maximum power point tracking (MPPT),Droop characteristics,Low voltage ride through,Reactive power injection
更新于2025-09-16 10:30:52
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Coordinative Low-Voltage-Ride-Through Control for the Wind-Photovoltaic Hybrid Generation System
摘要： The wind-photovoltaic (PV) hybrid renewable energy system (HRES), which consists of permanent magnet synchronous generators (PMSG) and PV arrays, is becoming a cost-effective electric source for powering islanded areas. However, high penetration of renewables makes the power system vulnerable to transient voltage faults, which undermines the stability of the future inverter-dominated grid. To address this issue, a coordinative low-voltage-ride-through (LVRT) control scheme is proposed for the operation of the wind-PV HRES in this paper. This control scheme will exploit the maximum energy inertia of the HRES for incorporating the power imbalance between the faulted grid and the renewable generators. An optimization problem is formulated to maximize the renewable energy harvesting within the operational and environmental limitations. To cope with different working conditions, four control processes are coordinated in an optimized manner during the LVRT period, namely (i) Adaptive DC-link voltage control, (ii) PMSG rotating speed control, (iii) PV energy curtailment control, and (iv) Blade pitch angle control. Besides, this control scheme applies a direct output control that can generate stable and accurate current as per grid code requirements. The results of the hardware-in-the-loop (HIL) experiment and the MATLAB-Simulink simulation are provided to verify the effectiveness of the proposed control scheme.
关键词： power system faults,Hybrid renewable energy system,low-voltage-ride-through,smart grid
更新于2025-09-12 10:27:22
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[IEEE 2019 IEEE Innovative Smart Grid Technologies - Asia (ISGT Asia) - Chengdu, China (2019.5.21-2019.5.24)] 2019 IEEE Innovative Smart Grid Technologies - Asia (ISGT Asia) - A strategy for suppressing the second harmonic of output power for photovoltaic grid-connected inverters with low voltage ride-through
摘要： When an unbalanced voltage drop occurs in the grid system, output power of distributed photovoltaic grid-connected system will generate second harmonics. In order to suppress the second harmonic, a new low voltage ride-through control strategy is proposed, which can adjust the harmonic suppression target according to the degree of voltage drop. This strategy can suppress the second harmonic of active power when the voltage drop is low, and suppress the second harmonic of reactive power when the voltage drop is large. The control strategy is simulated in MATLAB, and the results testified its effectiveness.
关键词： Photovoltaic grid-connected system,Harmonic suppression,Low voltage ride-through,Unbalanced voltage drop
更新于2025-09-11 14:15:04
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Probabilistic Short-Circuit Current in Active Distribution Networks Considering Low Voltage Ride-Through of Photovoltaic Generation
摘要： The probabilistic short-circuit current (PSCC) of photovoltaic generation is determined by the voltage sag at the grid connection and the low voltage ride-through of the unit during the grid fault, while the voltage sag and the low voltage ride-through are both stochastic. According to short-circuit current characteristics and Thevenin equivalent circuit in the transient state, this paper analyzes the changing trajectory of the equivalent internal potential of photovoltaic generation during the period of low voltage ride-through. To deal with the uncertainty of low voltage ride-through, the probability density function by the maximum entropy method is used to characterize the stochastic process of low voltage disconnection of photovoltaic generation. Based on the fault information, the calculation method of PSCC in active distribution network considering the uncertainty of low voltage ride-through of photovoltaic generation is proposed. Two cases of 9-node and 34-node distribution network are used to verify the effectiveness of the method. The obtained PSCC results can reasonably re?ect the actual short-circuit current level of the active distribution network.
关键词： probabilistic short-circuit current,low voltage ride-through,active distribution network,Photovoltaic
更新于2025-09-11 14:15:04
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[IEEE 2019 IEEE Innovative Smart Grid Technologies - Asia (ISGT Asia) - Chengdu, China (2019.5.21-2019.5.24)] 2019 IEEE Innovative Smart Grid Technologies - Asia (ISGT Asia) - Fault Analysis for Three Phase Unbalanced Distribution Network with Photovoltaic Generation Integration
摘要： Due to the asymmetry of three phase distribution network parameters, the traditional symmetrical method cannot meet the requirement for fault analysis. This paper aims to calculate the fault current of the unbalanced distribution network by employing the phase component modelling. A three-phase model of the unbalanced distribution network with photovoltaic generation system is proposed, considering the low voltage ride through control of photovoltaic generation system. A phase based iterative algorithm is explored to solve the three-phase voltage and short-circuit current. The impact of different connected locations and capacities of photovoltaic power generation on fault characteristics are analyzed.
关键词： unbalanced distribution network,fault calculation,low voltage ride through,photovoltaic generation system
更新于2025-09-11 14:15:04