Transient analysis of low-voltage ride-through in three-phase grid-connected converter with LCL filter using the nonlinear modal series method

2013 ◽  
Vol 105 ◽  
pp. 39-50 ◽  
Author(s):  
Wei Wang ◽  
Xikui Ma
Energies ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2899 ◽  
Author(s):  
Alexis B. Rey-Boué ◽  
N. F. Guerrero-Rodríguez ◽  
Johannes Stöckl ◽  
Thomas I. Strasser

This article deals with the vector control in dq axes of a three-phase grid-connected photovoltaic system with single-stage topology and low-voltage-ride-through capability. The photovoltaic generator is built using an array of several series-parallel Suntech PV modules and is modeled as a Lookup Table (two-dimensional; 2-D). The requirements adopted when grid voltage sags occur are based in both the IEC 61400-21 European normative and the allowed amount of reactive power to be delivered according to the Spanish grid code, which avoids the disconnection of the inverter under grid faults by a limitation in the magnitude of the three-phase output inverter currents. For this, the calculation of the positive- and negative-sequences of the grid voltages is made and a conventional three-phase Phase-Locked Loop is used for the inverter-grid synchronization, allowing the control of the active and reactive powers solely with the dq components of the inverter currents. A detailed enhanced flowchart of the control algorithm with low-voltage-ride-through capability is presented and several simulations and experiments using Matlab/SIMULINK and the Controller Hardware-in-the-Loop simulation technique, respectively, are run for several types of one- and three-phase voltage sags in order to validate its behavior.


2014 ◽  
Vol 945-949 ◽  
pp. 2891-2894
Author(s):  
Wen Juan Zhang ◽  
Zhi Xia Han

From a theoretical perspective, this paper develops a systematic approach to analyze the transient characteristics of the low voltage ride through in three-phase short-circuit rotor current. Firstly, the steady state current mathematical model of the system is described. And then, the short-circuit rotor current dynamic characteristic during the low voltage fault is analyzed, the resistance value and switching strategy of crowbar are discussed. Finally, the simulation results and the theoretical analysis manifest that appropriate crowbar reactance value and switching time can improve LVRT control characteristic and grid stability.


2014 ◽  
Vol 986-987 ◽  
pp. 1277-1281
Author(s):  
Tian Fa Liao ◽  
Yang Chun ◽  
Wen Si ◽  
Chang Wen Dong ◽  
Jia Xiang Xue

In this paper, 10KW three-phase three-level photovoltaic grid-tied inverter is applied as hardware platform. Considering the insufficiency of PV arrays power output and low overall efficiency due to grid voltage falls asymmetrically, P-R current controller is used to provide unsymmetrical positive and negative sequence current to the grid so that low voltage ride through (LVPT) in photovoltaic inverter can be achieved. Through the implement of experiments, it is well proved that the requirement of LVPT when the grid voltage falls asymmetrically can be met by applying the solution proposed in this paper.


2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Sajad Arab Ansari ◽  
Amir Reza Mizani ◽  
Siamak Ashouri ◽  
Javad Shokrollahi Moghani

Due to the fast growth of single-phase grid-connected photovoltaic (PV) systems, the existing grid codes are expected to be modified to guarantee the availability, quality, and reliability of the electrical system. Therefore, the future single-phase PV systems should become smarter and support low voltage ride-through (LVRT) capability, which are required for three-phase wind power systems. In this paper, the operation principle of a flyback inverter in a low-voltage ride-through operation is demonstrated in order to map future challenges. The steady state performance of the flyback inverter under voltage rise and drop conditions at boundary conduction mode (BCM) and discontinues conduction mode (DCM) is studied theoretically. The simulation results of the flyback inverter for various grid faults are presented to verify the theoretical analyses. The results indicate the fact that the flyback inverter at BCM condition can provide LVRT capability for photovoltaic microinverter applications in distributed generation (DG) systems, even though it does not need any auxiliary control branches and any limitations in components design.


2012 ◽  
Vol 608-609 ◽  
pp. 687-691
Author(s):  
Ze Xin Zhang ◽  
Guang Qing Bao

According to the provisions of low voltage ride through capability of wind turbines in the “large-scale design and technical specifications for wind farm to grid” of china, proposed a method to simulate this low voltage ride through grid voltage by computer simulation software. The simulation method is mainly used to simulate whether the wind turbines grid can meet the low voltage ride through requirements. In order to obtain the required grid voltage, the fault simulation circuit is divided into voltage dip part and voltage recovery part, which were used to simulated 20% & 90% voltage dip and the 20% grid voltage gradually recovered to 90% grid voltage. Three-phase fault modules for the voltage dip part, Three-phase programmable voltage source module for the voltage recovery part. The simulation results show that simulation system we build can simulate the required grid voltage.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Yongheng Yang ◽  
Frede Blaabjerg

The progressive growing of single-phase photovoltaic (PV) systems makes the Distribution System Operators (DSOs) update or revise the existing grid codes in order to guarantee the availability, quality, and reliability of the electrical system. It is expected that the future PV systems connected to the low-voltage grid will be more active with functionalities of low-voltage ride-through (LVRT) and the grid support capability, which is not the case today. In this paper, the operation principle is demonstrated for a single-phase grid-connected PV system in a low-voltage ride-through operation in order to map future challenges. The system is verified by simulations and experiments. Test results show that the proposed power control method is effective and the single-phase PV inverters connected to low-voltage networks are ready to provide grid support and ride-through voltage fault capability with a satisfactory performance based on the grid requirements for three-phase renewable energy systems.


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