Improved digital control scheme of three phase UPS inverter using double control strategy

This paper suggests an enhanced control scheme for a four-leg battery energy storage systems (BESS) under unbalanced and nonlinear load conditions operating in the isolated microgrid. Simplicity, tiny steady-state error, fast transient response, and low total harmonic distortion (THD) are the main advantages of the method. Firstly, a new decoupled per-phase model for the three-phase four-leg inverter is presented. It can eliminate the effect of power stage coupling on control design; thus, the three-phase four-leg power inverter can be viewed as three single input single output (SISO) control systems. Then, using an improved orthogonal signal generation method, the per-phase model of the four-leg inverter in the stationary and synchronous frame is derived. As the second step, a per-phase multi-loop control scheme for the four-leg inverter under unbalanced load conditions is suggested. The proposed control strategy has the ability to provide balanced output voltages under unbalanced load conditions by avoiding the need to deal with the symmetrical components. Finally, a multi-resonant harmonic compensator is used to actively prevent low-order harmonic currents to distort the output voltages of the three-phase four-leg grid-forming power converter. Simulations results are also presented to verify the performance of the suggested control strategy.

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Digital Control Strategy for Four Quadrant Operation of Three Phase BLDC Motor With Load Variations

IEEE Transactions on Industrial Informatics ◽

10.1109/tii.2012.2221721 ◽

2013 ◽

Vol 9 (2) ◽

pp. 974-982 ◽

Cited By ~ 52

Author(s):

C. Sheeba Joice ◽

S. R. Paranjothi ◽

V. Jawahar Senthil Kumar

Keyword(s):

Control Strategy ◽

Digital Control ◽

Bldc Motor ◽

Load Variations ◽

Three Phase ◽

Four Quadrant

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Modeling and simulation of three phases cascaded H-bridge grid-tied PV inverter

Bulletin of Electrical Engineering and Informatics ◽

10.11591/eei.v8i1.1225 ◽

2019 ◽

Vol 8 (1) ◽

pp. 1-9

Author(s):

Swetapadma Panigrahi ◽

Amarnath Thakur

Keyword(s):

Control Strategy ◽

Pi Controller ◽

Pv System ◽

Grid Current ◽

Pv Array ◽

Pv Inverter ◽

Simulink Model ◽

Three Phase ◽

Control Scheme ◽

Mppt Controller

In this paper a control scheme for three phase seven level cascaded H-bridge inverter for grid tied PV system is presented. As power generation from PV depends on varing environmental conditions, for extractraction of maximum power from PV array, fuzzy MPPT controller is incorporated with each PV array. It gives fast and accurate response. To maintain the grid current sinusoidal under varying conditions, a digital PI controller scheme is adopted. A MATLAB/Simulink model is developed for this purpose and results are presented. At last THD analysis is carried out in order to validate the performance of the overall system. As discussed, with this control strategy the balanced grid current is obtained keeping THD values with in the specified range of IEEE-519 standard.

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Research on Control Strategy for the Three-Phase Grid-Connected Inverter

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.614-615.1578 ◽

2012 ◽

Vol 614-615 ◽

pp. 1578-1582

Author(s):

Chun Qing Qi ◽

Yi Ruan ◽

Feng Wen Cao

Keyword(s):

Control Strategy ◽

Reactive Power ◽

Response Speed ◽

Current Control ◽

Loop Control ◽

Closed Loop Control System ◽

Three Phase ◽

Control Scheme ◽

Loop Control System ◽

Grid Connected Inverter

This paper proposes a control strategy，based on the grid voltage oriented vector control (VOC), which makes three-phase inverter control the active and reactive power of grid-connected inverter under the premise of the direct current control. This paper analyzes the principle of three phase photovoltaic grid connected inverter and describes the control structure of the inverter. The control strategy can overcome the deficiencies of the indirect current control scheme. This paper designs the current closed-loop control system, which not only improve the system dynamic response speed and output current waveform quality, while also reduce its sensitivity to parameter changes to improve the robustness of the system. The simulation results show the validity of control strategy proposed.

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