scholarly journals Separated Phase–Current Controls Using Inverter-Based DGs to Mitigate Effects of Fault Current Contribution from Synchronous DGs on Recloser–Fuse

2019 ◽  
Vol 9 (20) ◽  
pp. 4311 ◽  
Author(s):  
Boonyapakdee ◽  
Konghirun ◽  
Sangswang
Keyword(s):  
Dynamic Performance ◽  
Voltage Regulation ◽  
Current Control ◽  
Current Phase ◽  
Fault Current ◽  
Grid Voltage ◽  
Phase Current ◽  
Distributed Generators ◽  
Current Contribution ◽  
Measurement Units

Synchronous distributed generators (SDGs) significantly affect recloser–fuse coordination due to the high fault current contribution. This paper proposes a separated phase–current control using inverter-based distributed generators (IBDGs) to remove the effects of fault current contributions from SDGs during unsymmetrical faults. The three-phase current produced by IBDGs is independently controlled. While the total fault current is reduced by adjusting the current phase angle in the faulty phase, the energy in the DC-link capacitor (Cdc) is delivered to the grid in order to avoid the rise of DC-link voltage (Vdc) by means of injection of the active current into the nonfaulty phase. To maintain the proper grid voltage, the voltage regulation feature is installed in the IBDGs. Moreover, current estimations programmed within the IBDGs are introduced to avoid the performance degradation of separated phase–current controls caused by phasor measurement units (PMUs). The dynamic performance of the separated phase–current controls using IBDGs was evaluated using an IEEE 34-node radial test feeder. According to the simulation results, the IBDGs could eliminate the effects of fault current contributions from the SDG without interruption since the disconnections caused by excessive Vdc were prevented. They could also regulate the grid voltage in the nonfaulty phase.

Fault Current Contribution From Synchronous Machine and Inverter Based Distributed Generators

2007 ◽  
Vol 22 (1) ◽  
pp. 634-641 ◽  
Author(s):  
Natthaphob Nimpitiwan ◽  
Gerald Thomas Heydt ◽  
Raja Ayyanar ◽  
Siddharth Suryanarayanan
Keyword(s):  
Synchronous Machine ◽  
Fault Current ◽  
Distributed Generators ◽  
Current Contribution

scholarly journals Internal Model Current Control of Brushless Doubly Fed Induction Machines

Energies ◽  
2018 ◽  
Vol 11 (7) ◽  
pp. 1883 ◽  
Author(s):  
Mei Su ◽  
Weiyu Jin ◽  
Guanguan Zhang ◽  
Weiyi Tang ◽  
Frede Blaabjerg
Keyword(s):  
Internal Model ◽  
Dynamic Performance ◽  
Induction Machine ◽  
Current Control ◽  
Grid Voltage ◽  
Wind Energy Generation ◽  
Slip Ring ◽  
Internal Model Controller ◽  
Doubly Fed Induction Machine ◽  
Doubly Fed

In the wind energy generation system, the brushless doubly-fed induction machine (BDFIM) has shown significant application potential, since it eliminates the electric brush and slip ring. However, the complicated rotor structure increases the control difficulty, especially resulting in complicated coupled terms in the current sub-system, which deteriorates the dynamic performance and reduces the system robustness. In order to address the problems caused by complex coupled terms, an internal model current control strategy is presented for the BDFIM, and an active damping term is designed for suppressing the disturbance caused by the total resistance. The proposed method simplifies the controller parameters design, and it achieves the fast-dynamic response and the good tracking performance, as well as good robustness. On the other hand, the feedforward term composed by the grid voltage is added to the internal model controller in order to suppress the disturbance when the symmetrical grid voltage sag happens. Finally, the simulation and experimental results verify the feasibility and effectiveness of the proposed method.

Inductor Saturation Compensation in Three-Phase Three-Wire Voltage-Source Converters via Inverse System Dynamics-I

2020 ◽  
Author(s):  
Ziya Özkan ◽  
Ahmet Masum Hava
Keyword(s):  
Dynamic Model ◽  
Dynamic Performance ◽  
Current Control ◽  
Inverse System ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Two Phase ◽  
Inverse Dynamic ◽  
Three Phase ◽  
Steady State Current

In three-phase three-wire (3P3W) voltage-source converter (VSC) systems, utilization of filter inductors with deep saturation characteristics is often advantageous due to the improved size, cost, and efficiency. However, with the use of conventional synchronous frame current control (CSCC) methods, the inductor saturation results in significant dynamic performance loss and poor steady-state current waveform quality. This paper proposes an inverse dynamic model based compensation (IDMBC) method to overcome these performance issues. Accordingly, a review of inductor saturation and core materials is performed, and the motivation on the use of saturable inductors is clarified. Then, two-phase exact modelling of the 3P3W VSC control system is obtained and the drawbacks of CSCC have been demonstrated analytically. Based on the exact modelling, the inverse system dynamic model of the nonlinear system is obtained and employed such that the nonlinear plant is converted to a fictitious linear inductor system for linear current regulators to perform satisfactorily.

scholarly journals A Cost-Effective Decentralized Control for AC-Stacked Photovoltaic Inverters

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2262 ◽  
Author(s):  
Hua Han ◽  
Chao Luo ◽  
Xiaochao Hou ◽  
Mei Su ◽  
Wenbin Yuan ◽  
...  
Keyword(s):  
Decentralized Control ◽  
Cost Effective ◽  
Current Control ◽  
Control Mode ◽  
Communication Link ◽  
Grid Voltage ◽  
Point Tracking ◽  
Pv Inverter ◽  
Communication Links ◽  
Voltage Phase

For an AC-stacked photovoltaic (PV) inverter system with N cascaded inverters, existing control methods require at least N communication links to acquire the grid synchronization signal. In this paper, a novel decentralized control is proposed. For N inverters, only one inverter nearest the point of common coupling (PCC) needs a communication link to acquire the grid voltage phase and all other N − 1 inverters use only local measured information to achieved fully decentralized local control. Specifically, one inverter with a communication link utilizes the grid voltage phase and adopts current control mode to achieve a required power factor (PF). All other inverters need only local information without communication links and adopt voltage control mode to achieve maximum power point tracking (MPPT) and self-synchronization with grid voltage. Compared with existing methods, the communication link and complexity is greatly reduced, thus improved reliability and reduced communication costs are achieved. The effectiveness of the proposed control is verified by simulation tests.

Optimized neural network and adaptive neuro-fuzzy controlled dynamic voltage restorer for power quality performance

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Prashant Kumar ◽  
Sabha Raj Arya ◽  
Khyati D. Mistry
Keyword(s):  
Neural Network ◽  
Power Distribution ◽  
Fuzzy Inference ◽  
Dynamic Performance ◽  
Hybrid Approach ◽  
Voltage Regulation ◽  
Dynamic Voltage Restorer ◽  
Inference System ◽  
Intelligence System ◽  
Neuro Fuzzy

Abstract In this article, a hybrid approach is implemented namely, neural network training (NNT) based machine learning (ML) estimator inspired by artificial neural network (ANN) and self-adaptive neuro-fuzzy inference system (ANFIS) to tackle the voltage aggravations in the power distribution network (DN). In this work, potential of swarm intelligence technique namely particle swam optimization (PSO) is analysed to obtain an optimum prediction model with certain modifications in training algorithm parameters. In practice, when the systems are continuously subjected to parametric changes or external disturbances, then ample time is dedicated to tune the system to regain its stable performance. To improve the dynamic performance of the system intelligence-based techniques are proposed to overcome the shortcomings of conventional controllers. So, gain tuning process based on the intelligence system is a desirable choice. The statistical tools are used to proclaim the effectiveness of the controllers. The obtained MSE, RMSE, ME, SD and R were evaluated as 0.0015959, 0.039949, −0.00089838, 0.039941 and 1 in the training phase and 0.0015372, 0.039207, −0.0005657, 0.039203 and 1 in the testing phase, respectively. The results revealed that the ANFIS-PSO network model could accomplish a better DC voltage regulation performance when it is compared to the conventional PI. The proposed intelligence strategies confirm that the predicted DVR model based on NNT-ML and ANFIS has faster convergence speed and reliable prediction rate. Moreover, the simulation results show that the dynamic response is improved with proposed PSO based NNT based ML and ANFIS (Takagi-Sugeno) that significantly compensates the voltage based PQ issues. The proposed DVR is actualized in MATLAB/SIMULINK platform.

Modeling of steady state fault current contribution of inverter-connected generation in PSS/e

2021 ◽  
Author(s):  
Lukas Sigrist ◽  
Javier Renedo ◽  
Francisco Miguel Echavarren ◽  
Francisco Perez Thoden ◽  
Luis Rouco
Keyword(s):  
Steady State ◽  
Fault Current ◽  
Current Contribution
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