Improved Grid-Side Current Control of LCL-Filtered Grid-Tied Inverters Under Weak Grid Conditions

2019 ◽  
Author(s):  
Abdeldjabar Benrabah ◽  
Farid Khoucha ◽  
Khoudir Marouani ◽  
Abdelaziz Kheloui ◽  
Ali Raza ◽  
...  
Keyword(s):  
Current Control ◽  
Weak Grid ◽  
Grid Side

scholarly journals Emulation of grid-forming inverters using real-time PC and 4-quadrant voltage amplifier

2021 ◽  
Author(s):  
Wolf Schulze ◽  
Maurizio Zajadatz ◽  
Michael Suriyah ◽  
Thomas Leibfried
Keyword(s):  
Real Time ◽  
Control Method ◽  
Current Control ◽  
Control Methods ◽  
Test Bed ◽  
Test Scenario ◽  
Power Semiconductors ◽  
Voltage Amplifier ◽  
Grid Side ◽  
Virtual Synchronous Machine

AbstractA test bed for the evaluation of novel control methods of inverters for renewable power generation is presented. The behavior of grid-following and grid-forming control in a test scenario is studied and compared.Using a real-time capable control platform with a cycle time of 50 µs, control methods developed with Matlab/Simulink can be implemented. For simplicity, a three-phase 4‑quadrant voltage amplifier is used instead of an inverter. Thus, the use of modulation and switched power semiconductors can be avoided. In order to show a realistic behavior of a grid-side filter, passive components can be automatically connected as L‑, LC- or LCL-filter. The test bed has a nominal active power of 43.6 kW and a nominal voltage of 400 V.As state-of-the-art grid-following control method, a current control in the d/q-system is implemented in the test bed. A virtual synchronous machine, the Synchronverter, is used as grid-forming control method. In combination with a frequency-variable grid emulation, the behavior of both control methods is studied in the event of a load connection in an island grid environment.

Voltage Dynamics of Current Control Time-Scale in a VSC-Connected Weak Grid

2016 ◽  
Vol 31 (4) ◽  
pp. 2925-2937 ◽  
Author(s):  
Mingquan Zhao ◽  
Xiaoming Yuan ◽  
Jiabing Hu ◽  
Yabing Yan
Keyword(s):  
Time Scale ◽  
Current Control ◽  
Weak Grid ◽  
Control Time ◽  
Voltage Dynamics

scholarly journals Dynamic Modeling and Performance Analysis of PMSG- based Variable Speed WTG: Case Study of Adama Wind Farm I, Ethiopia

2021 ◽  
Vol 12 (2) ◽  
pp. 155-172
Author(s):  
Zenachew Muluneh ◽  
Gebremichael Teame
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Power Flow ◽  
Wind Farm ◽  
Reactive Power ◽  
Maximum Energy ◽  
Current Control ◽  
Speed Ratio ◽  
Variable Speed ◽  
Grid Side

In this paper, the performance of Permanent Magnet Synchronous Generator (PMSG) -based Variable Speed Wind Turbine Generator (WTG) at Adama Wind Farm I (WTG), connected to a grid is studied. To study the performance of the WTG, both machine and grid side converters are modeled and analyzed very well. On the machine side, maximum power point tracking (MPPT) for maximum energy extraction is done using the direct speed control (DSC) technique, which is linked with the optimal tip speed ratio for each wind speed value considered. On the grid side, dc-link voltage and reactive power flow to the grid are controlled. For this purpose, first, the simulation model of the system is prepared in MATLAB Simulink considering the dynamic mathematical model of the PMSG, and Wind Turbine Aerodynamic model using the user-defined function blocks. Then, the PI regulators designed for direct speed, torque (current) control, and dc-link voltage are employed in the model. Moreover, to study and analyze the behavior of the system in a variable speed operation, a wind speed starting from cut-in wind speed (3m/s) to the rated wind speed (11m/s) is applied in 4s. The simulation result of the existing system model shows that the actual values of performance variables correspond well with the analytical values of the system. In addition, the chosen control algorithms applied in the control system of the generator-side converter are hence verified.

A Control Method to Suppress Resonance and Improve Current Quality for Inverter System with LCL Filter

2014 ◽  
Vol 644-650 ◽  
pp. 3528-3533
Author(s):  
Yong Peng Lin ◽  
Shun Tao ◽  
Xiang Ning Xiao ◽  
Mei Rong Wu
Keyword(s):  
Control Method ◽  
Current Control ◽  
Utilization Efficiency ◽  
Control Effect ◽  
Lcl Filter ◽  
Loop Control ◽  
Grid Voltage ◽  
Grid Current ◽  
Differential Voltage ◽  
Grid Side

The LCL filter is easy to resonate, especially in the new energy power system with multiple inverters. The LCL filter resonant formulas are derived in this paper and a novel double closed loop control strategy combing with the structure of the LCL filter was proposed at the base on feedback of capacitor current as a result. In the control system, the inner loop feedback the first differential voltage of filter inductor at the grid side to damp the resonance and nature of first differential voltage of filter inductor is explained; the grid current outer loop achieves direct control of the grid current for high power factor and utilization efficiency. The simulation results show that the grid-side inductor voltage differential feedback control have a better current control effect both in the condition of the normal power grid voltage and distorted grid voltage, and the fluctuations of power and dc voltage are reduced.

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