Power Feedward Strategy of Grid-Connected Inverter Based on Direct Power Decoupling

Take into account grid inverter that using direct power control is vulnerable to the disturbance of grid voltage, a control algorithm is proposed based on the relationship between the power and voltage, which is deduced according to the mathematic model of the inverter that using double-loop control strategy. The change amount of the output power of inverter is added to the reference of power closed-loop as power feedforward, which improves the dynamic response to the grid voltage change. Simulations with EMTDC/PSCAD are carried out and the comparison of output power response to grid voltage change between control with and without power feedforward verifies its effectiveness.

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A Modified Grid-Connected Inverter Topology for Power Oscillation Suppression under Unbalanced Grid Voltage Faults

Energies ◽

10.3390/en14165057 ◽

2021 ◽

Vol 14 (16) ◽

pp. 5057

Author(s):

Cheng Luo ◽

Xikui Ma ◽

Lihui Yang ◽

Yongming Li ◽

Xiaoping Yang ◽

...

Keyword(s):

Output Power ◽

Output Current ◽

Grid Voltage ◽

Power Oscillation ◽

Power Simulation ◽

Point Of Common Coupling ◽

In Series ◽

Grid Connected Inverter ◽

Output Filter ◽

Unbalanced Grid

Under unbalanced grid voltage faults, the output power oscillation of a grid-connected inverter is an urgent problem to be solved. In the traditional topology of inverters, it is impossible to eliminate power oscillation and simultaneously maintain balanced output current waveform. In this paper, considering the solvability of reference current matrix equation, the inherent mechanism of inverter output power oscillation is analyzed, and a modified topology with auxiliary modules inserted in series between the inverter output filter and the point of common coupling (PCC) is proposed. Due to the extra controllable freedoms provided by auxiliary modules, the inverter could generate extra voltage to correct PCC voltage while keeping balance of output current, so as to eliminate the oscillation of output power. Simulation and experimental results verify the effectiveness of the proposed topology.

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Research on Voltage Oriented Control Strategy of Grid-Connected Inverter of Wind Power Generation

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.818.212 ◽

2013 ◽

Vol 818 ◽

pp. 212-217

Author(s):

Yong Yang ◽

Guang Ming Lan ◽

Zhi Qi Sun ◽

Jian Guo ◽

Zhong Qiang Zhang

Keyword(s):

Mathematical Model ◽

Power Control ◽

Closed Loop ◽

Control Strategies ◽

Closed Loop Control ◽

Direct Power ◽

Direct Power Control ◽

Two Phase ◽

Loop Control ◽

Grid Connected Inverter

Based on the dynamic mathematical model of three-phase grid-connected inverter, two kinds of control strategies are compared, one is double closed loop control based on grid voltage orientation theory, the other is direct power control. According to the mathematical model of two-phase rotating coordinates of the inverter, in double closed loop control theory, the purpose of control of the inverter by decoupling control and PI control is achieved. From the point of energy on direct power control system, the active, inactive power of output AC of inverter are calculated ,and suitable space voltage vector was selected after comparing with the given values to realize the direct control of the power set point. The basic theory of two control strategies and implementation method are included, and the simulation model was established based on MATLAB/Simulink. And their simulation results, characteristics of two kinds of control methods were compared through simulation data analysis. On the basic of results, the direct power control is better than the double closed loop control.

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A novel current controller design for grid-integrated PV inverter system

SN Applied Sciences ◽

10.1007/s42452-021-04290-4 ◽

2021 ◽

Vol 3 (3) ◽

Author(s):

Ayaz Ahmad ◽

L. Rajaji ◽

A. Iqbal

Keyword(s):

Controller Design ◽

Vital Role ◽

Current Feedback ◽

Lcl Filter ◽

Design Algorithm ◽

Grid Voltage ◽

Pv Inverter ◽

Current Controller ◽

Experimental Implementation ◽

Grid Connected Inverter

AbstractDistributed generators are playing a vital role in supporting the grid in ever-increasing energy demands. Grid code regulation must be followed when integrating the photovoltaic inverter system to the grid. The paper investigates and analyzes a controller model for grid-connected PV inverters to inject sinusoidal current to the grid with minimum distortion. To achieve better tracking and disturbance rejection, a DSP-based current controller is designed with LCL filter. The controller gets the current feedback from the grid, compares it with reference current, and calculates duty cycle to generate PWM pulses to trigger H-bridge converters. The grid voltage is loaded to the initial value in proposed PR controller to ensure the initial inverter voltage to match the grid voltage. The paper presents a novel current controller algorithm for grid-connected inverter system, and simulation is done. A detailed analysis has been carried out to validate the proposed design algorithm. Experimental implementation of the current controller in the DC/AC converter circuits with an LCL filter is done for 5.4 kW to validate and match the simulation model.

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