scholarly journals Active Disturbance Rejection Control Scheme for Reducing Mutual Current and Harmonics in Multi-Parallel Grid-Connected Inverters

Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4363 ◽  
Author(s):  
Muhammad Saleem ◽  
Byoung-Sun Ko ◽  
Si-Hwan Kim ◽  
Sang-il Kim ◽  
Bhawani Chowdhry ◽  
...  

With the increasing penetration of renewable energy sources into modern power systems, parallel inverters with LCL filters are commonly employed in the grid interface, giving rise to potential resonance problems. Among the different resonances, interactive resonance is triggered by interaction among inverters when different current references are applied to parallel inverters. It may also feature a mutual current that circulates among inverters instead of flowing into the grid and introduces harmonics or instability in the control system. In this paper, active disturbance rejection control based on a reduced-order extended state observer (RESO) was proposed for parallel inverters. With the proposed scheme, the interaction between inverters is considered as an exogenous disturbance caused by other parallel inverters, estimated by the RESO, and rejected by the controller. In the results, the mutual current and interactive harmonics, calculated via fast Fourier transform, were reduced with the proposed control scheme. Thus, the lower total harmonic distortion of each current was achieved. Additionally, the robust stability and less model-dependent control design are the other additive advantages over the derivative filtered capacitor voltage feedforward-based active damping using PI control. The simulation and real-time experimental results of the conventional and proposed scheme, obtained using the hardware-in-loop, were presented to verify the theoretical analysis under the similar and different current reference cases.

Electronics ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 357 ◽  
Author(s):  
Chunlin Song ◽  
Changzhu Wei ◽  
Feng Yang ◽  
Naigang Cui

This article presents a fixed-time active disturbance rejection control approach for the attitude control problem of quadrotor unmanned aerial vehicle in the presence of dynamic wind, mass eccentricity and an actuator fault. The control scheme applies the feedback linearization technique and enhances the performance of the traditional active disturbance rejection control (ADRC) based on the fixed-time high-order sliding mode method. A switching-type uniformly convergent differentiator is used to improve the extended state observer for estimating and attenuating the lumped disturbance more accurately. A multivariable high-order sliding mode feedback law is derived to achieve fixed time convergence. The timely convergence of the designed extended state observer and the feedback law is proved theoretically. Mathematical simulations with detailed actuator models and real time experiments are performed to demonstrate the robustness and practicability of the proposed control scheme.


2020 ◽  
Vol 42 (12) ◽  
pp. 2221-2233 ◽  
Author(s):  
Yun Cheng ◽  
Zengqiang Chen ◽  
Mingwei Sun ◽  
Qinglin Sun

Although the heat integrated distillation is an energy-efficient and environment-friendly separation technology, it has not been commercialized. One of the reasons is that the nonlinear dynamics and the interactions between various control loops have limited the performance of the traditional control strategy. To achieve a high-purity product concentration, a dynamic decoupling control strategy based on active disturbance rejection control (ADRC) is proposed. The effects of interactions, uncertainties and external disturbances can be estimated and rejected by using extended state observer. Considering the constraints on manipulated variables, an optimized ADRC is designed for the first-order system. Moreover, a concentration observer based on a nonlinear wave model is formulated to reduce the number of sensors. In the simulation research, the related internal model control (IMC), multi-loop ADRC and model predictive control (MPC) are compared with the proposed control scheme. The simulation results demonstrate the advantages of the proposed control scheme on tight control, decoupling performance and disturbance rejection for the high-purity heat integrated distillation column.


2013 ◽  
Vol 404 ◽  
pp. 603-608
Author(s):  
Qing Bo Wu ◽  
Fu Yang Chen ◽  
Chang Yun Wen

In this paper, a self-repairing control scheme for attitude control of a quadrotor helicopter via active disturbance rejection control is proposed. Firstly, a model of the quadrotor helicopter is gained by its dynamic equations with pitch, roll and yaw axis. Then the active disturbance rejection controller is introduced, which is used to design the control system. The control system consists of PID controller in inner-loop and ADRC controller in outer-loop. Disturbances and uncertainties can be compensated by the ADRC to achieve smaller tracking error. Finally, the simulation results of the four-rotor helicopter validate the efficiency and self-repairing capability of the proposed control algorithm, compared with that of the PID control and the separate ADRC control.


Electronics ◽  
2021 ◽  
Vol 10 (23) ◽  
pp. 2995
Author(s):  
Fan Wang ◽  
Peng Liu ◽  
Feng Jing ◽  
Bo Liu ◽  
Wei Peng ◽  
...  

This paper proposes a novel robust control scheme for tip trajectory tracking of a lightweight flexible single-link arm. The developed control scheme deals with the influence of tip payload changes and disturbances during the working process of the flexible arm, thus realizing the accurate tracking for the tip reference trajectory. The robust control scheme is composed of an inner loop and an outer loop. The inner loop adopts the traditional PD control, and an active disturbance rejection control (ADRC) with a sliding mode (SM) compensation is designed in the outer loop. Moreover, the sliding mode compensation is mainly used to cope with the disturbance estimation error from the extended state observer (ESO), by which the insensitivity to tip payload variations and strong disturbance resistance is achieved. Finally, some numerical simulations are performed to support the theoretical analysis. The results show that the system is more robust to the tip mass variations of the arm and more resistant to the external torque after adding the sliding mode robustness term to the ADRC.


2020 ◽  
Vol 10 (7) ◽  
pp. 2515 ◽  
Author(s):  
Wameedh Riyadh Abdul-Adheem ◽  
Ibraheem Kasim Ibraheem ◽  
Ahmad Taher Azar ◽  
Amjad J. Humaidi

A decentralized control scheme is developed in this paper based on an improved active disturbance rejection control (IADRC) for output tracking of square Multi-Input-Multi-Output (MIMO) nonlinear systems and compared with the decoupled control scheme. These nonlinear MIMO systems were subjected to exogenous disturbances and composed of high couplings between subsystems, input couplings, and uncertain elements. In the decentralized control scheme, it was assumed that the input couplings and subsystem couplings were both parts of the generalized disturbance. Moreover, the generalized disturbance included other components, such as exogenous disturbances and system uncertainties, and it was estimated within the context of Active Disturbance rejection Control (ADRC) via a novel nonlinear higher order extended state observer (NHOESO) from the measured output and canceled from the input channel in a real-time fashion. Then, based on the designed NHOESO, a separate feedback control law was developed for each subsystem to achieve accurate output tracking for given reference input. With the proposed decentralized control scheme, the square MIMO nonlinear system was converted into approximately separate linear time invariant Single-Input-Single-Output (SISO) subsystems. Numerical simulations in a MATLAB environment showed the effectiveness of the proposed technique, where it was applied on a hypothetical MIMO nonlinear system with strong couplings and vast uncertainties. The proposed decentralized control scheme reduced the total control signal energy by 20.8% as compared to the decoupled control scheme using Conventional ADRC (CADRC), while the reduction was 27.18% using the IADRC.


Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1132 ◽  
Author(s):  
Fan Zhang ◽  
Yali Xue ◽  
Donghai Li ◽  
Zhenlong Wu ◽  
Ting He

Supercritical circulating fluidized bed (CFB) is one of the prominent clean coal technologies owing to the advantages of high efficiency, fuel flexibility, and low cost of emission control. The fast and flexible load-tracking performance of the supercritical CFB boiler-turbine unit presents a promising prospect in facilitating the sustainability of the power systems. However, features such as large inertia, strong nonlinearity, and multivariable coupling make it a challenging task to harmonize the boiler’s slow dynamics with the turbine’s fast dynamics. To improve the operational flexibility of the supercritical CFB unit, a burning carbon based decentralized active disturbance rejection control is proposed. Since burning carbon in the furnace responds faster than throttle steam pressure when the fuel flow rate changes, it is utilized to compensate the dynamics of the corresponding loop. The parameters of the controllers are tuned by optimizing the weighted integrated absolute error index of each loop via genetic algorithm. Simulations of the proposed method on a 600 MW supercritical CFB unit verify the merits of load following and disturbance rejection in terms of less settling time and overshoot.


Machines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 22
Author(s):  
Xuyang Cao ◽  
Zhiwei Wang ◽  
Xingang Zhang

A polar crane is a large-scale special lifting equipment operated in a nuclear power plant. To address the precise locating control problem of a polar crane with the center of gravity shifting, with cross-coupling, and with external disturbance, an effective control scheme is proposed in this paper. Firstly, a nonholonomic constraint dynamic model of the polar crane is established according to the Lagrange–Rouse equation. Then, an expansion state observer (ESO) of the active disturbance rejection control (ADRC) method is applied to estimate and compensate the cross-coupling disturbance in real-time. To improve the robustness and convergence speed of the control system, the nonsingular terminal sliding mode (NTSM) control method is incorporated with ADRC and the stability of the controller is proven by the Lyapunov function approach. Furthermore, to solve the problem of redundant actuation and to reduce trajectory deviation of the bridge truck, the contact forces of the horizontal guide device are introduced into the quadratic programming (QP) optimization algorithm. Finally, the effectiveness and superiority of the proposed control scheme are illustrated by simulation results.


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