scholarly journals Multivariable State-Feedback Controller Design for PV Inverter Connected to a Weak Grid

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4441
Author(s):  
MUSENGIMANA Antoine ◽  
Haoyu Li ◽  
Xuemei Zheng ◽  
Yanxue Yu
Keyword(s):  
State Feedback ◽  
Control Method ◽  
Controller Design ◽  
State Feedback Control ◽  
System Stability ◽  
Weak Grid ◽  
Pv Inverter ◽  
Stability Robustness ◽  
Power Disturbances ◽  
Point Of Common Coupling

This paper presents a robust multi-input multi-output (MIMO) state-feedback control scheme for a photovoltaic (PV) inverter connected to a weak grid. For a weak grid, the point of common coupling (PCC) voltage is very sensitive to the power disturbances and it is dynamically coupled to the PLL dynamics. So far, most of the control methods do not take into accounts these couplings. Therefore, in this paper, the MIMO controller was designed taking into account the dynamics of the phase-locked loop (PLL) and coupling effects between PCC voltage and the active power to enhance the system’s robustness. As result, the robust performance of the PV inverter interfaced to a weak grid was yielded. In addition, the sensitivity of the system to PLL was eliminated, allowing the use of larger PLL bandwidth even in a very weak grid. Based on the eigenvalues analysis method, a comparative study between the proposed control method and the conventional vector control method was performed. The proposed method is verified with simulations in PLECS and real-time simulations in the RT Box. The results show that the proposed MIMO control method preserves the system stability robustness against any change of grid strength, generated power and PLL bandwidth.

A New Iterative Identification and Control Method of Closed-Loop Power System Based on Ambient Signals

2015 ◽  
Vol 798 ◽  
pp. 261-265
Author(s):  
Miao Yu ◽  
Chao Lu
Keyword(s):  
Power System ◽  
Closed Loop ◽  
Control Method ◽  
Controller Design ◽  
Design Method ◽  
Stability Margin ◽  
System Stability ◽  
Iterative Identification ◽  
Effective Performance ◽  
And Control

Identification and control are important problems of power system based on ambient signals. In order to avoid the model error influence of the controller design, a new iterative identification and control method is proposed in this paper. This method can solve model set and controller design of closed-loop power system. First, an uncertain model of power system is established. Then, according to the stability margin of power system, stability theorem is put forward. And then controller design method and the whole algorithm procedure are given. Simulation results show the effective performance of the proposed method based on the four-machine-two-region system.

The Motor Active Flexible Suspension and Its Dynamic Effect on the High-Speed Train Bogie

2017 ◽  
Vol 140 (6) ◽  
Author(s):  
Yuan Yao ◽  
Yapeng Yan ◽  
Zhike Hu ◽  
Kang Chen
Keyword(s):  
Control System ◽  
Time Delay ◽  
High Speed ◽  
State Feedback ◽  
State Feedback Control ◽  
System Stability ◽  
High Speed Train ◽  
Suspension Parameters ◽  
Linear And Nonlinear ◽  
Hunting Stability

We put forward the motor active flexible suspension and investigate its dynamic effects on the high-speed train bogie. The linear and nonlinear hunting stability are analyzed using a simplified eight degrees-of-freedom bogie dynamics with partial state feedback control. The active control can improve the function of dynamic vibration absorber of the motor flexible suspension in a wide frequency range, thus increasing the hunting stability of the bogie at high speed. Three different feedback state configurations are compared and the corresponding optimal motor suspension parameters are analyzed with the multi-objective optimal method. In addition, the existence of the time delay in the control system and its impact on the bogie hunting stability are also investigated. The results show that the three control cases can effectively improve the system stability, and the optimal motor suspension parameters in different cases are different. The direct state feedback control can reduce corresponding feed state's vibration amplitude. Suppressing the frame's vibration can significantly improve the running stability of bogie. However, suppressing the motor's displacement and velocity feedback are equivalent to increasing the motor lateral natural vibration frequency and damping, separately. The time delay over 10 ms in control system reduces significantly the system stability. At last, the effect of preset value for getting control gains on the system linear and nonlinear critical speed is studied.

Robust stabilization of longitudinal tracking for cooperative adaptive cruise control considering input saturation

2020 ◽  
Vol 34 (35) ◽  
pp. 2050409
Author(s):  
Youguo He ◽  
Xiaoxiao Tian ◽  
Jie Shen ◽  
Chaochun Yuan ◽  
Yingkui Du
Keyword(s):  
Adaptive Cruise Control ◽  
Control Method ◽  
Controller Design ◽  
Actuator Saturation ◽  
Kinematic Model ◽  
Input Saturation ◽  
Robust Stabilization ◽  
State Feedback Control ◽  
Cruise Control ◽  
Cooperative Adaptive Cruise Control

This paper is concerned with the problem of constraint control for cooperative adaptive cruise control (CACC) with input saturation and input-additive uncertainties. An integrated longitudinal kinematic model of CACC system including vehicle model and constant time headway is established taking into account input saturation and input-additive uncertainties. According to the system’s robustness requirements under input saturation, the saturation control method is introduced. In order to achieve robust global stabilization of the system, a low-gain state feedback control law is designed by using linear low-gain feedback and gain scheduling. Meanwhile, in order to avoid the saturation of the control system, the low gain parameter [Formula: see text] is introduced into the controller design. Finally, the simulation of homogeneous and heterogeneous platoons is carried out by MATLAB/Simulink, which verifies the feasibility and effectiveness of the designed controller. Compared with the SMC controller, saturation controller successfully suppresses the acceleration amplification in the process of propagation along the vehicle platoon, avoids actuator saturation and realizes the stability of CACC system.

scholarly journals Delay-Dependent Guaranteed Cost Controller Design for Uncertain Neural Networks with Interval Time-Varying Delay

2012 ◽  
Vol 2012 ◽  
pp. 1-16 ◽  
Author(s):  
M. Rajchakit ◽  
P. Niamsup ◽  
T. Rojsiraphisal ◽  
G. Rajchakit
Keyword(s):  
Neural Networks ◽  
State Feedback ◽  
Closed Loop ◽  
Controller Design ◽  
Sufficient Conditions ◽  
Performance Measure ◽  
State Feedback Control ◽  
Linear Matrix ◽  
Delayed Neural Networks ◽  
Guaranteed Cost

This paper studies the problem of guaranteed cost control for a class of uncertain delayed neural networks. The time delay is a continuous function belonging to a given interval but not necessary to be differentiable. A cost function is considered as a nonlinear performance measure for the closed-loop system. The stabilizing controllers to be designed must satisfy some exponential stability constraints on the closed-loop poles. By constructing a set of augmented Lyapunov-Krasovskii functionals combined with Newton-Leibniz formula, a guaranteed cost controller is designed via memoryless state feedback control, and new sufficient conditions for the existence of the guaranteed cost state feedback for the system are given in terms of linear matrix inequalities (LMIs). Numerical examples are given to illustrate the effectiveness of the obtained result.

LOOKING FORWARD TO THE INTELLIGENT ELECTRICAL MACHINE: ELECTRONICS AND MACHINES COMBINE THEIR ABILITIES

1995 ◽  
Vol 05 (01) ◽  
pp. 45-63
Author(s):  
DIETRICH NAUNIN
Keyword(s):  
State Feedback ◽  
Position Control ◽  
Controller Design ◽  
Supply Voltage ◽  
Induction Machine ◽  
State Feedback Control ◽  
Electrical Machine ◽  
Precise Position ◽  
Electric Cars ◽  
Drive Systems

Electrical machines, more than 150 years old, have long been distinguished according to their mechanical structure and frequencies of their supply voltage (or current). This is not true any more after the electronic revolution. Since the fast development in power electronics as well as in control electronics these electronics can give any motor any desired speed-torque characteristic and any motor can become a servodrive having a very precise position control. By implementing digital control algorithms, mainly the cascaded, the state feedback or the cascaded state feedback control, and — if necessary, in addition — adaptive control procedures which compensate the variation of system parameters in the controller, the "intelligent electrical machine" — either with the synchronous or with the induction machine — is created. It is part of mechatronics. It can be installed in modern automated systems, in robots and tool machines, in all kinds of industrial drive systems as well as in locomotives and electric cars. Also modern methods like fuzzy logic and neural networks can be used. It seems that they will not create a second revolution in the control itself, but in the application areas of drives. They add some interesting features to the intelligent electrical machine and make it even more intelligent. They could also speed up the controller design in future.

A Reduced-Order H∞ Controller Design for Linear Structures

2012 ◽  
Vol 170-173 ◽  
pp. 3334-3337
Author(s):  
Lian Hua Hu ◽  
Xiao Feng Yang
Keyword(s):  
State Feedback ◽  
Parametric Design ◽  
Controller Design ◽  
State Feedback Control ◽  
Matrix Equations ◽  
Linear Structures ◽  
Reduced Order ◽  
Disturbance Decoupling ◽  
Necessary And Sufficient ◽  
Sylvester Matrix Equations

A robust reduced-order H∞ controller for the linear structures is investigated. This controller is with disturbance decoupling. First, a necessary and sufficient condition for the H∞ state feedback control problem is established. Second, based on the parametric design approach for generalized Sylvester matrix equations, we obtain a reduced-order H∞ controller for linear structures. Finally, numerical example is given to illustrate the validity of the results.

scholarly journals A Systematic Controller Design for a Photovoltaic Generator with Boost Converter Using Integral State Feedback Control

2019 ◽  
Vol 9 (2) ◽  
pp. 4030-4036 ◽  
Author(s):  
Z. R. Labidi ◽  
H. Schulte ◽  
A. Mami
Keyword(s):  
Feedback Control ◽  
State Space ◽  
State Feedback ◽  
Controller Design ◽  
State Space Model ◽  
Boost Converter ◽  
State Feedback Control ◽  
Solar Irradiation ◽  
Photovoltaic Array ◽  
Pv Generator

In this paper, a systematic controller design for a photovoltaic generator with boost converter using integral state feedback control is proposed. It is demonstrated that the state–space feedback enables the extraction of maximum available power under variable loads. For this purpose, a control-oriented state-space model of a photovoltaic array connected to a DC load by a boost converter is derived. This model is then linearized by one working point, but no further simplifications are made. The design-oriented model contains the dynamics of PV generator, boost converter, and the load. The controller design is based on the augmented model with an integral component. The controller is validated by a detailed plant model implemented in Simscape. The robustness of the controller with variable solar irradiation and DC load changes is demonstrated.

scholarly journals An Enhanced Control Strategy for Mitigation of State-Transition Oscillation Phenomena in Grid-Forming Self-Synchronized Converter System with Islanded Power System

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8453
Author(s):  
Ki Ryong Kim ◽  
Sangjung Lee ◽  
Jong-Pil Lee ◽  
Jaesik Kang
Keyword(s):  
Power System ◽  
Control Strategy ◽  
State Transition ◽  
Reactive Power ◽  
Phase Synchronization ◽  
Control Method ◽  
System Stability ◽  
Electromagnetic Transient ◽  
Point Of Common Coupling ◽  
Hardware In Loop

This paper proposes an enhanced control strategy for mitigating state-transition oscillations in active and reactive power responses of self-synchronized converter system to secure the islanded power system stability. The self-synchronized converter is well known for “grid-forming” that is able to operate to stand-alone mode (SAM) providing grid voltage and frequency without phase synchronization units. Although the grid-forming (GFM) is self-synchronized, the inherent synchronization principle causes system degradation in which should maintain a point of common coupling (PCC) voltage for critical loads as well as transitions from grid-connected mode (GCM) to SAM and vice versa. Therefore, this paper focuses on resolving the inherent oscillatory issues in GFM self-synchronized converter system (especially adopted ‘synchronverter’ principle), and proposes a control strategy for controllability improvement based on stability analysis for smooth state-transition under islanded power system. The efficacy of the proposed control method is verified through a high-fidelity electromagnetic transient (EMT) simulation with case studies on 30kW synchronverter system and further experimental hardware-in-loop system (HILS) test with Opal-RT (OP-5707) platform.

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