Research on Single-Phase Inverter Dual Loop Control Technology with Feed-Forward Compensation

2014 ◽  
Vol 960-961 ◽  
pp. 1285-1289
Author(s):  
Shu Jun Yao ◽  
Jun Luo ◽  
Min Xiao Han ◽  
Yang Cheng Xiang Song
Keyword(s):  
Control Strategy ◽  
Current Loop ◽  
Nonlinear Load ◽  
New Approach ◽  
Feed Forward ◽  
Loop Control ◽  
Assignment Method ◽  
Control Scheme ◽  
Waveform Distortion ◽  
Single Phase Inverter

A new approach of dual closed-loop control strategy is proposed, and the internal cause of the inverter output voltage waveform distortion is analyzed in this paper. The ability to resist load disturbance is improved by load current feed-forward compensation in the approached scheme. With inner current loop improving the speed of dynamic response, nonlinear load adaptability is enhanced. Pole assignment method is used to design controller parameters, the control scheme is simulated in PSCAD/EMTDC, the nice performance of the proposed control strategy is verified by the simulation results.

scholarly journals Improved Voltage Unbalance and Harmonics Compensation Control Strategy for an Isolated Microgrid

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2688 ◽  
Author(s):  
Mohammad Jafar Hadidian Moghaddam ◽  
Akhtar Kalam ◽  
Mohammad Reza Miveh ◽  
Amirreza Naderipour ◽  
Foad H. Gandoman ◽  
...  
Keyword(s):  
Control Strategy ◽  
Power Converter ◽  
Phase Model ◽  
Nonlinear Load ◽  
Loop Control ◽  
Single Input Single Output ◽  
Three Phase ◽  
Control Scheme ◽  
Unbalanced Load ◽  
Load Conditions

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.

The Position Servo Control Strategy of High Dynamic Response Based on Electric Steering Gear

2013 ◽  
Vol 310 ◽  
pp. 524-531
Author(s):  
Guo Ping Zhao ◽  
Hong Xing Wu ◽  
Min Xiu Kong ◽  
Li Yi Li
Keyword(s):  
Vector Control ◽  
Control Strategy ◽  
Servo System ◽  
Current Loop ◽  
Feed Forward ◽  
Loop Control ◽  
Feed Forward Control ◽  
High Dynamic ◽  
Position Servo ◽  
The Impact

This paper studies the current loop, velocity loop and position loop controller of PMSM position servo system for Electric steering gear servo system. It makes research around the principle of PMSM vector control and three control loop control strategy. The control strategy bases on the principle of vector control of PMSM when id=0 and uses the classic PI control theory. A new method of decouple control for the current of direct axis and cross axis direct is presented. It will overcome the impact of EMF when the motor is working in high dynamic. The system uses the feed-forward control to compensate the position deviation of permanent magnet synchronous motor using in the steering gear. The paper also researches transfer function of feed-forward control of the location, and establishes the feed-forward controller model of the position loop. Simulation results demonstrate the effectiveness of our proposed scheme.

scholarly journals Feedback Linearization and Sliding Mode Control for VIENNA Rectifier Based on Differential Geometry Theory

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Xiang Lu ◽  
Yunxiang Xie ◽  
Li Chen
Keyword(s):  
Differential Geometry ◽  
Sliding Mode Control ◽  
Control Strategy ◽  
Feedback Linearization ◽  
Sliding Mode ◽  
Current Loop ◽  
Loop Control ◽  
Mode Control ◽  
Vienna Rectifier ◽  
Feedback Linearization Control

Aiming at the nonlinear characteristics of VIENNA rectifier and using differential geometry theory, a dual closed-loop control strategy is proposed, that is, outer voltage loop using sliding mode control strategy and inner current loop using feedback linearization control strategy. On the basis of establishing the nonlinear mathematical model of VIENNA rectifier ind-qsynchronous rotating coordinate system, an affine nonlinear model of VIENNA rectifier is established. The theory of feedback linearization is utilized to linearize the inner current loop so as to realize thed-qaxis variable decoupling. The control law of outer voltage loop is deduced by utilizing sliding mode control and index reaching law. In order to verify the feasibility of the proposed control strategy, simulation model is built in simulation platform of Matlab/Simulink. Simulation results verify the validity of the proposed control strategy, and the controller has a strong robustness in the case of parameter variations or load disturbances.

The Control Strategy and Simulation of Three-Phase Grid-Connected Photovoltaic System

2012 ◽  
Vol 608-609 ◽  
pp. 164-168
Author(s):  
Jian Jun Su ◽  
Men Yue Hu ◽  
Hong Yan Gong ◽  
Hai Tao Sun ◽  
Zhi Jian Hu ◽  
...  
Keyword(s):  
Control Strategy ◽  
Photovoltaic System ◽  
Current Loop ◽  
Maximum Power Point ◽  
Loop Control ◽  
Point Tracking ◽  
Power Point Tracking ◽  
Three Phase ◽  
Power Point ◽  
Research Situation

Firstly the research situation for grid-connected photovoltaic (PV) is introduced, then, the engineering mathematical model of PV cells is introduced. The perturbation and observation algorithm is chosen as the maximum power point tracking (MPPT) algorithm. The SPWM double-loop control strategy with outer voltage loop and inner current loop is described and a three-phase grid-connected photovoltaic model is established. The simulation results demonstrate the validity and correctness of the simulation model built in this paper.

scholarly journals An Input-Parallel-Output-Series Switched-Capacitor Three-level Boost Converter with a Three-Loop Control Strategy

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2631
Author(s):  
Jianfei Chen ◽  
Caisheng Wang ◽  
Jian Li
Keyword(s):  
Control Strategy ◽  
Current Loop ◽  
Loop Control ◽  
Dc Microgrids ◽  
Solar Power Generation ◽  
Capacitor Voltage ◽  
Industry Applications ◽  
Voltage Balance ◽  
Simulation And Experiment ◽  
Parallel Output

There has been increasing interest for industry applications, such as solar power generation, fuel cell systems, and dc microgrids, in step-up dc-dc converters with reduced number of components, low component stress, small input ripples and high step-up ratios. In this paper, an input-parallel-output-series three-level boost (IPOS-SC-TLB) converter is proposed. In addition to achieving the required performance, the input and output terminals can share the same ground and an automatic current balance function is also achieved in the IPOS-SC-TLB converter. Besides, a capacitor voltage imbalance mechanism was revealed and a three-loop control strategy composed of output voltage loop, input current loop and voltage-balance loop was proposed to address the voltage imbalance issue. Finally both simulation and experiment studies have been conducted to verify the effectiveness of the IPOS-SC-TLB converter and the three-loop control strategy.

scholarly journals Virtual Synchronous Generator Control of VSC-HVDC System Based on MMC of Hybrid Topology

2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
Jie Wu ◽  
Chuanjiang Li
Keyword(s):  
Control Strategy ◽  
Closed Loop ◽  
Structural Characteristics ◽  
Synchronous Generator ◽  
Current Control ◽  
Current Loop ◽  
Power Module ◽  
Loop Control ◽  
Hybrid Topology ◽  
Virtual Synchronous Generator

For a VSC-HVDC transmission system based on a hybrid topology converter of full-bridge and half-bridge, a kind of virtual synchronous generator (VSG) control strategy which can be applied to modular multilevel converter (MMC) grid-connected structure was researched and proposed. First, based on the conventional VSG control strategy, the energy stored in the equivalent capacitor of MMC power module was used to imitate the rotor inertia of synchronous generator. The characteristics of generator can be simulated during transient frequency fluctuations and it can help relieve the power fluctuations. Secondly, with respect to the structural characteristics of the direct grid connection through the reactor on the AC side of the MMC, which is unlike the microgrid inverter, there are no additional filter capacitors. So, the existing commonly used VSG control strategy of the microgrid inverter and double-closed-loop structure composed of filter capacitor voltage and AC current cannot be directly applied. For this, a method where the given values of inner current loop are calculated by grid impedance matrix was used. So, a double-closed-loop control structure composed of a power outer loop based on VSG control and a current inner loop is obtained. It can effectively improve the current control capability during the transient process. Finally, a hybrid MMC simulation model was built based on PSCAD to verify the correctness and effectiveness of the proposed methods.

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 simplified control strategy for single-phase UPS inverters

2014 ◽  
Vol 62 (2) ◽  
pp. 367-373 ◽  
Author(s):  
M. Monfared
Keyword(s):  
Control Strategy ◽  
Single Phase ◽  
Design Procedure ◽  
Feedback Signal ◽  
Current Loop ◽  
Loop Control ◽  
Closed Loop Control System ◽  
Loop Control System ◽  
Uninterruptible Power ◽  
Lc Filter

Abstract Though there are many strategies to control single-phase uninterruptible power supply (UPS) inverters, they suffer from some drawbacks, the main being complexity. This paper proposes a simple dual-loop controller for the single-phase UPS inverter with the LC filter. The suggested control scheme uses the capacitor current as the feedback signal in the inner current loop. No fictitious phase generation or reference frame transformations are required, and simple proportional gains are employed as both voltage and current regulators. A feedforward of the derivative of the output voltage is also proposed, which significantly improves the performance of the closed loop control system. Then, based on the model of the inverter with the proposed control strategy, a simple and systematic design procedure is presented. Finally, the theoretical achievements are supported by extensive simulations.

Sign in / Sign up

Export Citation Format

Share Document