Decoupling Control Strategy for Conergy Three-Level Three Phase Grid Converter

2014 ◽  
Vol 986-987 ◽  
pp. 1205-1209 ◽  
Author(s):  
Shi Min Shan ◽  
Wei Chi Ou ◽  
Ya Feng
Keyword(s):  
Control Strategy ◽  
Closed Loop ◽  
High Efficiency ◽  
Reactive Power ◽  
Decoupling Control ◽  
Active And Reactive Power ◽  
Three Phase ◽  
Integral Controller ◽  
Proportional Integral Controller ◽  
Grid Connected Inverter

Conergy three-level NPC topology is often used in grid connected inverter due to its high efficiency, fewer switching devices and better EMI performance. Traditional half-bridge topology can be transformed to Conergy NPC topology by adding bi-direction switches. This paper proposed a novel control strategy for Conergy three-level NPC three phase grid converter with real and reactive power closed-loop controller in the synchronous d-q rotating frame. The power control loop is based on the feed forward decoupling of d-axis and q-axis components of the output current, thus the active and reactive power can be controlled separately. Additionally a proportional-integral controller is added to enhance the robustness of the power controller. Simulation results verify the effectiveness of the proposed strategy.

Modified Power Compensation Control Strategy of Three-Phase Grid-Connected Inverter under Unbalanced Grid Voltage Conditions

2015 ◽  
Vol 740 ◽  
pp. 335-338 ◽  
Author(s):  
Shao Hua Sun ◽  
Hong Qi Ben
Keyword(s):  
Control Strategy ◽  
Reactive Power ◽  
Positive Sequence ◽  
Grid Voltage ◽  
Compensation Control ◽  
Active And Reactive Power ◽  
Three Phase ◽  
Grid Connected Inverter ◽  
Three Phase Inverter ◽  
Unbalanced Grid

Control strategy under unbalanced grid voltage conditions is one of the most important issues for grid-connected inverter. Under unbalanced grid voltage conditions, the 2nd active and reactive power ripples generate, they pollute the grid. To meet the demands of IEEE Std.929-2000, this paper proposed a modified power compensation control strategy; the proposed solution is based on direct power control. To provide accurate compensating power, the power model of three-phase inverter under unbalanced grid voltage conditions is given, using the positive sequence current component and the negative sequence voltage component, the compensating powers are calculated in details. Theoretical analysis and comparative simulation verification are presented to demonstrate the effectiveness of the proposed control strategy.

scholarly journals Optimal P-Q Control of Grid-Connected Inverters in a Microgrid Based on Adaptive Population Extremal Optimization

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2107 ◽  
Author(s):  
Min-Rong Chen ◽  
Huan Wang ◽  
Guo-Qiang Zeng ◽  
Yu-Xing Dai ◽  
Da-Qiang Bi
Keyword(s):  
Constrained Optimization ◽  
Optimization Problem ◽  
Reactive Power ◽  
Active Power ◽  
Adaptive Genetic Algorithm ◽  
Constrained Optimization Problem ◽  
Extremal Optimization ◽  
Active And Reactive Power ◽  
Three Phase ◽  
Grid Connected Inverter

The optimal P-Q control issue of the active and reactive power for a microgrid in the grid-connected mode has attracted increasing interests recently. In this paper, an optimal active and reactive power control is developed for a three-phase grid-connected inverter in a microgrid by using an adaptive population-based extremal optimization algorithm (APEO). Firstly, the optimal P-Q control issue of grid-connected inverters in a microgrid is formulated as a constrained optimization problem, where six parameters of three decoupled PI controllers are real-coded as the decision variables, and the integral time absolute error (ITAE) between the output and referenced active power and the ITAE between the output and referenced reactive power are weighted as the objective function. Then, an effective and efficient APEO algorithm with an adaptive mutation operation is proposed for solving this constrained optimization problem. The simulation and experiments for a 3kW three-phase grid-connected inverter under both nominal and variable reference active power values have shown that the proposed APEO-based P-Q control method outperforms the traditional Z-N empirical method, the adaptive genetic algorithm-based, and particle swarm optimization-based P-Q control methods.

Vector Decoupling Control Strategy for Three-Phase Voltage Source PWM Rectifier

2013 ◽  
Vol 336-338 ◽  
pp. 450-453
Author(s):  
Jian Ying Li ◽  
Wei Dong Yang ◽  
Ni Na Ma
Keyword(s):  
Power Factor ◽  
Control Strategy ◽  
Reactive Power ◽  
Decoupling Control ◽  
Voltage Source ◽  
Pwm Rectifier ◽  
Phase Voltage ◽  
Unity Power Factor ◽  
Three Phase ◽  
Rotating Coordinates

In view of the fact that active power and reactive power have coupling relation, a novel vector decoupling control strategy is presented for three-phase voltage source PWM rectifier. In the paper, the power control mathematical mode of the PWM rectifier is deduced based on the mathematical model of rectifier in synchronous d-q rotating coordinates, and a new voltage feed forward decoupling compensation control strategy is proposed. The simulation results show that the voltage and current of the three-phase PWM rectifier have better respond preference, the current aberrance is smaller and the voltage is steady under the control strategy. The PWM rectifier can implement PWM commute with unity power factor, but also feed back the energy to AC side with unity power factor.

Proportional-Resonant Controller Applied to DSTATCOM in a Hybrid Hydro-PV Generation System

2020 ◽  
Author(s):  
Gabriel M. Coco ◽  
Lucas G. Scherer ◽  
Felipe B. Grigoletto ◽  
Robinson F. de Camargo
Keyword(s):  
Control Strategy ◽  
Reactive Power ◽  
Disturbance Compensation ◽  
Generation System ◽  
Active And Reactive Power ◽  
Three Phase ◽  
Resonant Controller ◽  
Static Compensator ◽  
Pv Generation ◽  
Generation Hybrid

In distribution power generation, hybrid systems play an important role, mainly due its flexibility and reliability. This paper deals with the development of a control strategy for hybrid hydro-PV generation system employing a three-phase three-legs Split-Source Inverter (SSI) like a distribution synchronous static compensator (DSTATCOM). The SSI has the ability to feed ac loads with a boost characteristic. In addition, the proposed control strategy ensures regulation for balanced output ac voltages and load disturbance compensation of self excited induction generator (SEIG) based systems, providing the required active and reactive power. The modeling of the system and the design of the resonant controller are presented in detail. In addition, simulation results are presented to demonstrate the performance of the proposed control strategy.

scholarly journals Improved PR Control Strategy for an LCL Three-Phase Grid-Connected Inverter Based on Active Damping

2021 ◽  
Vol 11 (7) ◽  
pp. 3170
Author(s):  
Yahui Li ◽  
Jing Zhang ◽  
Zhenghang Hao ◽  
Peng Tian
Keyword(s):  
Coordinate System ◽  
Control Strategy ◽  
Reactive Power ◽  
Current Control ◽  
Active Damping ◽  
Power Calculation ◽  
Frequency Method ◽  
Proportional Integral ◽  
Three Phase ◽  
Grid Connected Inverter

Aiming at the problem of power coupling and complicated decoupling in the d-q coordinate system of a three-phase grid-connected inverter, a current closed-loop control strategy based on an improved QPIR (quasi-proportional integral resonant) controller in the α-β two-phase static coordinate system is proposed. Firstly, the mathematical model of an LCL three-phase grid-connected inverter is established, and its instantaneous power calculation equation is deduced. Secondly, the frequency method is applied to compare and analyze the proportional resonant, quasi-proportional resonant, and improved current controller, and the appropriate improved controller parameters are obtained according to the traditional proportional integral controller parameter design method and the weight coefficient. Finally, the improved controller is compared with the traditional controller in the simulation model of the LCL three-phase grid-connected inverter based on active damping. The results show that the proposed improved current control strategy has good dynamic response characteristics, can realize the non-static error control of grid-connected current, and realizes the decoupling control of active power and reactive power when the load jumps. At the same time, the results also prove the superiority of the proposed control strategy and verify its effectiveness.

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

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.

scholarly journals A Control Strategy of a Single-phase H6-type Grid-connected Inverter with Low Harmonic Current

2018 ◽  
Vol 173 ◽  
pp. 02041
Author(s):  
Lin Chunxu ◽  
Zhou Chunhua ◽  
Li Wei ◽  
Chen Rui
Keyword(s):  
Control Strategy ◽  
Single Phase ◽  
Closed Loop ◽  
High Efficiency ◽  
Control Method ◽  
Harmonic Distortion ◽  
Outer Loop ◽  
Lcl Filter ◽  
Loop Control ◽  
Grid Connected Inverter

In order to reduce the total harmonic distortion (THD) of the grid-connected current caused by the high-frequency switching of the inverter, this paper combines the high efficiency single-phase H6-type inverter with LCL filter. The double closed-loop control method that consists of grid-connected current outer loop and capacitor current inner loop is put forward, by which a resonance peak of a low damping LCL filter is eliminated. In the grid-connected current outer loop, quasi proportion resonant (QPR) controller is adopted to overcome the steady-state error and weak anti-jamming capability in traditional PI controller. Finally, a simulation model is built in SIMULINK to verify the research. The simulation results show that, based on the single-phase H6-type inverter and LCL filter, the double closed-loop QPR control strategy can achieve the static error free tracking control of grid-connected current, which makes the system more stable and reduces the THD of grid-connected current effectively.

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