scholarly journals Multiport Isolated link with Current-Fed Z-Source Converters to Manage Power Imbalance in PV Applications

Electronics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 280 ◽  
Author(s):  
Jose M. Sandoval ◽  
Victor Cardenas ◽  
Manuel A. Barrios ◽  
Mario Gonzalez Garcia ◽  
Janeth Alcala

In order to address power imbalance in large-scale PV systems, this paper presents a multiport isolated medium-frequency (MF) link to process different power levels from PV arrays, using current-fed Z-source inverters (CZSI) modules to drive the energy from the PV array to the MF link in a single power stage. The MF link provides the galvanic isolation required by many codes and standards to integrate a system to the grid. The multiport configuration of the MF link allows the system to process different power levels on each primary port and, being all ports magnetically coupled, provide balanced power levels on secondary ports which can be used for multilevel converters applications. Additionally, the current-fed version of the Z-source topology offers natural protection against short-circuit damage enhancing reliability of the system. The analysis of CZSI cells and the study of asymmetrical power levels transference, as well as simulation and experimental results are presented.

Mathematics ◽  
2021 ◽  
Vol 9 (13) ◽  
pp. 1474
Author(s):  
Ruben Tapia-Olvera ◽  
Francisco Beltran-Carbajal ◽  
Antonio Valderrabano-Gonzalez ◽  
Omar Aguilar-Mejia

This proposal is aimed to overcome the problem that arises when diverse regulation devices and controlling strategies are involved in electric power systems regulation design. When new devices are included in electric power system after the topology and regulation goals were defined, a new design stage is generally needed to obtain the desired outputs. Moreover, if the initial design is based on a linearized model around an equilibrium point, the new conditions might degrade the whole performance of the system. Our proposal demonstrates that the power system performance can be guaranteed with one design stage when an adequate adaptive scheme is updating some critic controllers’ gains. For large-scale power systems, this feature is illustrated with the use of time domain simulations, showing the dynamic behavior of the significant variables. The transient response is enhanced in terms of maximum overshoot and settling time. This is demonstrated using the deviation between the behavior of some important variables with StatCom, but without or with PSS. A B-Spline neural networks algorithm is used to define the best controllers’ gains to efficiently attenuate low frequency oscillations when a short circuit event is presented. This strategy avoids the parameters and power system model dependency; only a dataset of typical variable measurements is required to achieve the expected behavior. The inclusion of PSS and StatCom with positive interaction, enhances the dynamic performance of the system while illustrating the ability of the strategy in adding different controllers in only one design stage.


2013 ◽  
Vol 448-453 ◽  
pp. 1732-1737
Author(s):  
Liu Bin ◽  
Hong Wei Cui ◽  
Li Xu ◽  
Kun Wang ◽  
Zhu Zhan ◽  
...  

This paper analyses the characteristics of large-scale offshore wind farm collection network and the impact of the medium voltage collection system optimization,while from the electrical technology point,it proposes the short circuit current of the collection network computational model and algorithms,based on the principle of equivalent circuit.Taking a wind power coolection system planned for a certain offshore wind farm planning for example, the validity of the model and algorithm is verified.


2021 ◽  
Author(s):  
V. Sreeram ◽  
M. Rajkumar ◽  
S. S. Reddy ◽  
T. Gurudev ◽  
Maroti

Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3743
Author(s):  
Rui Li ◽  
Fangyuan Shi ◽  
Xu Cai ◽  
Haibo Xu

Photovoltaic (PV) power generation has shown a trend towards large-scale medium- or high-voltage integration in recent years. The development of high-frequency link PV systems is necessary for the further improvement of system efficiency and the reduction of system cost. In the system, high-frequency high-step-up ratio LLC converters are one of the most important parts. However, the parasitic parameters of devices lead to a loss of zero-voltage switching (ZVS) in the LLC converter, greatly reducing the efficiency of the system, especially in such a high-frequency application. In this paper, a high-frequency link 35 kV PV system is presented. To suppress the influences of parasitic parameters in the LLC converter in the 35 kV PV system, the influence of parasitic parameters on ZVS is analyzed and expounded. Then, a suppression method is proposed to promote the realization of ZVS. This method adds a saturable inductor on the secondary side to achieve ZVS. The saturable inductor can effectively prevent the parasitic elements of the secondary side from participating in the resonance of the primary side. The experimental results show that this method achieves a higher efficiency than the traditional method by reducing the magnetic inductance.


2021 ◽  
Vol 54 (1) ◽  
pp. 147-154
Author(s):  
Issam Griche ◽  
Sabir Messalti ◽  
Kamel Saoudi

The uncertainty of wind power brings great challenges to large-scale wind power integration. The conventional integration of wind power is difficult to adapt the demand of power grid planning and operation. This paper proposes an instantaneous power control strategy for voltage improvement in power networks using wind turbine improving the dynamical response of power systems performances (voltage and transient stability) after fault. In which the proposed control algorithm based on a new advanced control strategy to control the injected wind power into power system. The efficiency of developed control strategy has been tested using IEEE 9 Bus. Simulation results have showed that the proposed method perform better to preserve optimal performances over wide range of disturbances for both considered scenarios studied short circuit and variable loads.


Author(s):  
Mohammed Bouzidi ◽  
Abdelkader Harrouz ◽  
Tadj Mohammed ◽  
Smail Mansouri

<p>The inverter is the principal part of the photovoltaic (PV) systems that assures the direct current/alternating current (DC/AC) conversion (PV array is connected directly to an inverter that converts the DC energy produced by the PV array into AC energy that is directly connected to the electric utility). In this paper, we present a simple method for detecting faults that occurred during the operation of the inverter. These types of faults or faults affect the efficiency and cost-effectiveness of the photovoltaic system, especially the inverter, which is the main component responsible for the conversion. Hence, we have shown first the faults obtained in the case of the short circuit. Second, the open circuit failure is studied. The results demonstrate the efficacy of the proposed method. Good monitoring and detection of faults in the inverter can increase the system's reliability and decrease the undesirable faults that appeared in the PV system. The system behavior is tested under variable parameters and conditions using MATLAB/Simulink.</p>


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