Improvement of power quality for three-phase grids using single-phase DG with active filter function units

Author(s):  
Keiji Wada ◽  
Hidehito Yoshida
2014 ◽  
Vol 687-691 ◽  
pp. 3411-3414
Author(s):  
Jia Yong Chen ◽  
Kun Ya Guo ◽  
Peng Jin ◽  
Shu Han Wang

Electrified railway traction transformer is a pivot that connects the electric locomotive and the public grid. Therefore, power quality problems caused by electric locomotive such as three-phase voltage imbalance, great voltage fluctuation and high harmonic content can be transmitted to the public grid via the traction transformer. To solve this problem, the solution of two sets of single-phase SVG (Static Var Generator) in back-to-back operation to solve power quality problems of the electrified railway is raised. This solution has been proved by practice effective in improving power quality of the traction transformer.


2019 ◽  
Vol 16 (3) ◽  
pp. 289-310 ◽  
Author(s):  
Vinay Naguboina ◽  
Satish Gudey

In this work, a Three phase Transformerless Hybrid Series Active Power Filter (THSeAF) based on Sliding Mode Control (SMC) is proposed to mitigate the voltage and current distortions present in an electrical distribution systems (EDS). A Sliding Mode Controller is designed by controlling the parameters present on the load side as well as source side of the system. Three separate voltage source converters (VSC) are used. The mod1elling of the system is derived by considering a single-phase system by using state space analysis. The frequency response characteristics have been derived for the single-phase system and the stability of the system is studied. It is observed that the system has good stability margins when the SMC is applied at the source side compared to load side. Simulation results obtained in PSCAD/EMTDC v4.6 have been observed for power quality issues like voltage sags, voltage swells, voltage distortions, voltage unbalances and their concurrent occurrence. The approach of stationary reference frame was used for source side control and PQ theory is used for load side control. It is observed that the proposed controller works well in obtaining a stable and constant load voltage during these power quality issues. The difference in settling time observed is around 4 ms for the load side and source side control. The THD present in the load voltage is near about 1%. The SMC is found to be robust in obtaining a constant load voltage with low THD and an improved power factor.


Ingeniería ◽  
2017 ◽  
Vol 22 (2) ◽  
pp. 254 ◽  
Author(s):  
Oswaldo Lopez-Santos ◽  
Sebastián Tilaguy-Lezama ◽  
Sandra Patricia Rico-Ramírez ◽  
Luis Darío Cortes-Torres

Context: Microinverters are widely used in modular photovoltaic installations but its operation with reduced power is limited to inject real power into the grid. One way to optimize the use of microinverters consist of providing them the Active Power Filtering (APF) capability, which allows its use as both distributed generation and compensation unit even under unfavorable conditions of insolation. With this approach, the output stage of the microinverter can provide reactive and distortive components of power in order to compensate power quality defects of a localized load.Method: This paper proposes a non-linear control strategy to integrate the APF function in a single-phase two-stage photovoltaic microinverter. The proposal involves the use of the single-phase P-Q theory to generate the current reference, sliding mode control to achieve a robust tracking of that reference and linear robust control to maintain the power balance regulating the DC-link voltage of the microinverter. The proposed control does not require the use of low-pass filters and in turn uses a recursive average computation improving the general performance of the system.Results: The theoretical approach is validated by means of simulation results in which appropriate levels of harmonic distortion are obtained in the grid-side current for different load types and power levels. The robustness of the control system is tested by applying disturbances in the harmonic content of the load current and its power level obtaining an appropriate dynamic performance adapted to the demands of the application.Conclusions: The main advantage of this proposal is the possibility to add the active filter function to coventional microinverters extending its capability to power conditioning only integrating some algorithms. A simple design method to ensure reliability, robustness and high power quality is detailed.Language: English 


2008 ◽  
Vol 30 (8) ◽  
pp. 476-485 ◽  
Author(s):  
Abdelmadjid Chaoui ◽  
Fateh Krim ◽  
Jean-Paul Gaubert ◽  
Laurent Rambault

2012 ◽  
Vol 263-266 ◽  
pp. 649-654
Author(s):  
Yan Wei Zheng ◽  
Zhong Hai Bai ◽  
Zhi Quan Feng

To balance three-phase loads in distribution network with abundant of single-phase loads, the idea of three-phase adjustment and wiring method is proposed in this paper. Three-phase adjustment controller is designed, and the least load adjustment strategy is proposed, which can adjust the three-phase load to roughly balance automatically. The system can solve the serious three-phase unbalance problem of the lines with single-phase load, which may instead of capacitive compensation in low voltage distribution network. It can improve power quality and reduce network losses.


2020 ◽  
Vol 178 ◽  
pp. 01009
Author(s):  
Maxim Chernyshov ◽  
Valery Dovgun ◽  
Sergei Temerbaev ◽  
Zumeyra Shakurova

The article considers a hybrid power quality conditioner (HQPC) for 3-phase 4-wire systems with a distributed modular structure. Some conditioner modules provide compensation for the component currents and voltages that form the negative and zero sequence systems. The open structure of the HQPC, consisting of independent modules, allows compensating for distortions of currents and voltages of the 3-phase network caused by the nonlinear nature and asymmetry of single-phase loads. The compensation characteristics of the proposed conditioner were researched using a model developed in the MatLab environment. The simulation showed that the proposed conditioner can ensure normalization of power quality in 3-phase 4-wire system at various modes of network operation.


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