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.

Zero-Sequence Current Control of Modular Active Power Filter for High Power Three-Phase Three-Wire Electrical Networks

2006 ◽  
Vol 7 (3) ◽  
Author(s):  
Benhabib Choukri ◽  
Poure Philippe ◽  
Saadate Shahrokh
Keyword(s):  
High Power ◽  
Control Strategy ◽  
Reactive Power ◽  
Active Power ◽  
Current Control ◽  
Electrical Networks ◽  
Three Phase ◽  
Zero Sequence ◽  
Power Capability ◽  
Averaged Model

Since the development of the first control strategy for the active power filters (APF) introduced by H. Akagi [H. Akagi, Y. Kanazawa,A. Nabae, Generalized theory of the instantaneous reactive power in three-phase circuits, in: Proceedings of International Power Electronics Conference, Tokyo, Japan (1983) 1375–1386.], many efforts have been concentrated to improve their performances. However, when electrical networks supplies high current non-linear loads, a single inverter-based APF has limited power capability. In this paper, we studied parallel operation achieving high power level. More particularly, we examined a modular APF based on two three-phase inverters. This structure allows zero-sequence current circulating through the inverters, as demonstrated by using averaged modelling of the APF. To solve this problem and based on previous averaged model, we proposed a new optimal control strategy, suppressing the zero-sequence circulating current. Simulation results validate the proposed control.

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.

A Reference Compensation Current Control of Grid-Connected Inverter for Three-Phase Distributed Generators

2013 ◽  
Vol 433-435 ◽  
pp. 1183-1187 ◽  
Author(s):  
Shao Ru Zhang ◽  
Shao Yuan Li
Keyword(s):  
Control Strategy ◽  
Distribution Systems ◽  
Reactive Power ◽  
Neutral Current ◽  
Power Converter ◽  
Active Power ◽  
Current Control ◽  
Renewable Energy Resources ◽  
Current Harmonics ◽  
Grid Connected Inverter

Renewable energy resources (RES) are being increasingly connected in distribution systems by utilizing power electronic converters. However, the extensive use of power electronics has resulted in a rise in power quality (PQ) concerns faced by the utility. A novel control strategy implementing reference compensation current was proposed in this paper. So that these grid-connected inverters can achieve maximum benefits when they installed in 3-phase 4-wire distribution systems. The inverter is controlled to perform as a multi-function device by incorporating active power filter functionality. The inverter can thus be utilized as: 1) power converter to transfer active power from RES to the grid, and 2) load reactive power demand support; 3) current harmonics compensation at PCC; and 4) current unbalance and neutral current compensation in case of 3-phase 4-wire system. Moreover, with adequate control of grid-interfacing inverter, all the four objectives can be accomplished either individually or simultaneously. Simulation results show the validity and capability of the novel proposed control strategy.

Research on Combined Control Strategy of Three-Phase Photovoltaic Grid-Connected Inverter Based on Fuzzy PI Controller

2011 ◽  
Vol 347-353 ◽  
pp. 591-600
Author(s):  
Nguyen Viet Ngu ◽  
Hong Hua Wang ◽  
Le Thi Minh Tam
Keyword(s):  
Control Strategy ◽  
Control Method ◽  
Pi Controller ◽  
Current Control ◽  
Three Phase ◽  
Combined Control ◽  
Fuzzy Pi Controller ◽  
Bus Voltage ◽  
Grid Connected Inverter ◽  
Pv Grid

The control objective of three-phase photovoltaic (PV) grid-connected inverter is to generate high quality and stable AC sinusoidal output power with the same phase angle, frequency and amplitude compatible with the grid-connected voltage. To overcome the shortcoming of the normal current PWM control method and traditional PI algorithm, this paper researches a combined control strategy of three phase PV grid-connected inverter based on fuzzy PI controller. The combined control strategy switches different PWM current control method among the hysteretic PWM, SVPWM, hysteretic current SVPWM according to the error between command current and feedback current，and the d-axis command current is output of fuzzy PI controller of DC bus voltage. The simulation model of the combined control strategy for three phase PV grid-connected inverter based on normal PI controller is built with Matlab, simulation results verified the combination control strategy based on fuzzy PI controller has excellent performances.

The Simulation Study of Direct-Current Control Technology for Three-Phase Voltage Type Rectifier

2014 ◽  
Vol 556-562 ◽  
pp. 2105-2109
Author(s):  
Rong Jun
Keyword(s):  
Coordinate System ◽  
Reactive Power ◽  
Control Method ◽  
Current Control ◽  
Topological Classification ◽  
Voltage Source ◽  
Pwm Rectifier ◽  
Phase Voltage ◽  
Two Phase ◽  
Three Phase

The diode uncontrolled rectifier or the phase controlled rectifier is widely used in conventional rectifier link, thus the conventional rectifier link on the grid inject a large number of harmonics and reactive power, and they cause a severe grid “pollution”. This paper starts from the basic principles of the PWM rectifier, then the paper discusses the topological classification of three-phase PWM rectifier in detail. Based on topological structure, the paper builds the mathematical model of three-phase stationary coordinate system and two-phase rotating coordinate system. Based on space voltage vector, the paper studies PWM control method in-depth and simulates in Matlab/Simulink. The correctness of the theoretical study of three-phase voltage source PWM rectifier system is verified by the simulation results.

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.

Sign in / Sign up

Export Citation Format

Share Document