scholarly journals Predictive Direct Flux Control—A New Control Method of Voltage Source Inverters in Distributed Generation Applications

Energies ◽  
2017 ◽  
Vol 10 (4) ◽  
pp. 428
Author(s):  
Jiefeng Hu
Keyword(s):  
Distributed Generation ◽  
Control Method ◽  
Voltage Source ◽  
Flux Control ◽  
Voltage Source Inverters

scholarly journals New adaptive droop control with combined line impedance estimation method for parallel inverters

2016 ◽  
Vol 19 (4) ◽  
pp. 45-64
Author(s):  
Phuong Minh Le ◽  
Duy Vo Duc Hoang ◽  
Hoa Thi Xuan Pham ◽  
Huy Minh Nguyen
Keyword(s):  
Kalman Filter ◽  
Control Method ◽  
Least Squares Method ◽  
Estimation Method ◽  
Load Sharing ◽  
Phase Lock Loop ◽  
Power Sharing ◽  
Voltage Source ◽  
Droop Control ◽  
Voltage Source Inverters

This paper presents a new load sharing control between paralleled three-phase inverters in an islanded-microgrid based on the line impedance estimation online by the use of the Kalman filter. We can solve the mismatch of power sharing when the line impedance changes due to the temperature and frequency, significant differences of line parameters and requirements of Plug-and-Play mode of inverters connected to the microgrid. Moreover, the paper also presents a new Droop control method working with the line impedance which is different from the Droop traditional algorithm when the line impedance is assumed pure resistance R or pure inductance X. In the paper, the line impedance estimation for parallel inverters uses the least squares method combined with Kalman filter. In addition, secondary control loops are designed to restore the voltage amplitude and frequency of the microgrid by using a combined nominal value SOGI-PLL with generalized integral block and phase lock loop to exactly monitor the voltage magnitude and frequency phase at common PCC. Control model has been simulated in Matlab/Simulink with three voltage source inverters connected in parallel for different ratios of the power sharing. The simulation results have shown the accuracy of the proposed control method. Therefore, the proposed adaptive droop control method based on line impedance estimation can be an alternative one for load sharing control in islanded microgrids.

scholarly journals Direct torque control of doubly fed induction motor using three-level NPC inverter

2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Najib El Ouanjli ◽  
Aziz Derouich ◽  
Abdelaziz El Ghzizal ◽  
Mohammed Taoussi ◽  
Youness El Mourabit ◽  
...  
Keyword(s):  
Induction Motor ◽  
Control Method ◽  
System Modeling ◽  
Direct Torque Control ◽  
Harmonic Distortion ◽  
Torque Control ◽  
Voltage Source ◽  
Modeling And Control ◽  
Voltage Source Inverters ◽  
Doubly Fed

Abstract This article presents the direct torque control (DTC) strategy for the doubly fed induction motor (DFIM) connected to two three-level voltage source inverters (3LVSIs) with neutral point clamped (NPC) structure. This control method allows to reduce the torque and flux ripples as well as to optimize the total harmonic distortion (THD) of motor currents. The use of 3LVSI increases the number of generated voltage, which allows improving the quality of its waveform and thus improves the DTC strategy. The system modeling and control are implemented in Matlab/Simulink environment. The analysis of simulation results shows the better performances of this control, especially in terms of torque and flux behavior, compared to conventional DTC.

A Non-Isolated Buck-Boost Grid-Connected Inverter with no Shoot-Through Problem

2013 ◽  
Vol 732-733 ◽  
pp. 1247-1250
Author(s):  
Zhi Lei Yao ◽  
Jia Rong Kan ◽  
Guo Wen Hu
Keyword(s):  
Distributed Generation ◽  
Output Voltage ◽  
High Reliability ◽  
Input Voltage ◽  
Current Control ◽  
Voltage Source ◽  
Voltage Source Inverters ◽  
Hysteresis Current Control ◽  
Bridge Type ◽  
Grid Connected Inverter

The grid-connected inverters required for distributed generation systems should have high reliability. However, a shoot-through problem, which is a major killer of the reliability of the inverters, exists in the conventional bridge-type voltage-source inverters. In order to solve the aforementioned problem, a non-isolated buck-boost grid-connected inverter with no shoot-through problem is proposed. The hysteresis current control is used. The output voltage of the proposed grid-connected inverter can be larger or lower than the input voltage. The operating principle is illustrated. Simulation verifies the theoretical analysis.

scholarly journals A New Soft-Switching Solution in Three-Level Neutral-Point-Clamped Voltage Source Inverters

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2247
Author(s):  
Zbigniew Szular ◽  
Bartosz Rozegnal ◽  
Witold Mazgaj
Keyword(s):  
Control System ◽  
Control Algorithm ◽  
Control Method ◽  
Neutral Point ◽  
Soft Switching ◽  
Voltage Source ◽  
Voltage Source Inverters ◽  
Switching Losses ◽  
Switching Method ◽  
Selection Of

This paper presents a new soft-switching solution recommended for three-level neutral-point-clamped inverters. The operation principles of the proposed solution, working stages, selection of elements, and the control algorithm are comprehensively discussed herein. The control method of the inverter main switches is the same as that of the switches of an inverter operating according to the hard-switching technique. The correctness of the proposed solution was confirmed by the results of different tests using a laboratory neutral-point-clamped inverter with rated parameters of 3 kW, 2 × 150 V, 12 A, and 3 kHz. Numerical analyses were performed for the inverter of rated power 1.2 MW. The switching losses of the inverter operating with the proposed solution were compared with those of an inverter with hard-switching method. The proposed soft-switching solution increased the inverter efficiency and its competitiveness in relation to other proposals because there were no connections between switches and capacitors or inductors, which pose a risk of damaging the inverter when disturbances in the control system appear.

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