An adaptive Virtual Impedance Control Method to Enhance PCC Voltage Quality of Islanded Microgrid

2019 ◽  
Author(s):  
Yifan Zhang ◽  
Junfei Han ◽  
Shibo Wang ◽  
Zhe Dong
Keyword(s):  
Control Method ◽  
Impedance Control ◽  
Voltage Quality ◽  
Islanded Microgrid ◽  
Virtual Impedance

Improving robotic impedance control performance employing a cascaded controller based on virtual dynamics model

2022 ◽  
pp. 095440622110235
Author(s):  
Guanghui Liu ◽  
Bing Han
Keyword(s):  
Control Method ◽  
Robot Manipulator ◽  
Impedance Control ◽  
Industrial Robot ◽  
Mechanical Impedance ◽  
Superior Performance ◽  
Admittance Control ◽  
Dynamics Model ◽  
External Loop ◽  
Virtual Impedance

We propose a cascaded impedance control algorithm based on a virtual dynamics model (VDM) to achieve robust and effective mechanical impedance for a robot interacting with unknown environments. This cascaded controller consists of an internal loop of virtual impedance control based on a VDM and an external loop of impedance reference control. The VDM-based virtual impedance control can achieve the same effect as the conventional admittance control; its intermediate output of force/torque serves as the input for the external loop reference impedance control. Therefore, this cascaded controller shows superior performance by combining the advantages of admittance control and impedance control. We evaluate the controller in multiple-contact experiments on a six-degrees of freedom (6-DOF) industrial robot manipulator. The result shows that under various contact situations such as soft and rigid surfaces and free space, the proposed method can rapidly track the target and effectively maintain stability. In the experiments conducted on the robot in contact with various environments, the proposed control method reduced the steady-state error by more than 20% compared with the conventional admittance control.

scholarly journals Control-Loop-Based Impedance Enhancement of Grid-Tied Inverters for Harmonic Suppression: Principle and Implementation

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2874
Author(s):  
Fei Wang ◽  
Lijun Zhang ◽  
Hui Guo ◽  
Xiayun Feng
Keyword(s):  
Control Method ◽  
Impedance Control ◽  
Current Loop ◽  
Harmonic Suppression ◽  
Control Loop ◽  
Output Impedance ◽  
Loop Control ◽  
Control Loops ◽  
Capacitor Voltage

To understand different control loops that have been proposed to improve the quality of current into grid from the perspective of output impedance, control-loop-based output impedance enhancement of grid-tied inverters for harmonic suppression is proposed in this paper. The principle and generalized control loop deduction are presented for reshaping the output impedance. Taking a traditional LCL (Inductor-Capacitor-Inductor)-type inverter with dual-loop control as an example, different kinds of control loop topologies are derived step by step and further optimized for the implementation of the proposed principle. Consequently, the improved control consists of a filtering-capacitor voltage loop, and a grid current loop is found which can remove the existing inner capacitor current loop and therefore simplify the control. Finally, the effectiveness of the proposed control method is compared with the existing method and both are verified by simulations and experiments.

Research on the Space Manipulator Control in Capturing Object Based on Noncontact Impedance Control

2012 ◽  
Vol 546-547 ◽  
pp. 1014-1019 ◽  
Author(s):  
Zhi Gang Chen ◽  
Cui Ru Wu ◽  
Guang Yu Zhang
Keyword(s):  
Control Method ◽  
Impedance Control ◽  
Joint Space ◽  
Space Manipulator ◽  
Object Based ◽  
Space Manipulators ◽  
Impedance Parameters ◽  
The Impact ◽  
Virtual Impedance ◽  
Manipulator Control

This paper discusses the control of free flying space manipulators in the impact process which happens in the capturing operation. To solve the intense coupling of the kinematics and dynamics between the space manipulator and the base, this paper builds the noncontact impedance control model of the 6-joint space manipulator system, which can control the space manipulator before impacting with the objects. Computer simulations are performed to verify that the noncontact impedance control method can make the end-effector of the space manipulator keep desired dynamic characteristics and the adjustment of virtual impedance parameters can control the impact force value efficiently.

scholarly journals Distributed Adaptive Virtual Impedance for Reactive Power Sharing in Microgrid

2020 ◽  
pp. 135-140
Author(s):  
Harini M and Dr.S.Chitra
Keyword(s):  
Power Quality ◽  
Reactive Power ◽  
Control Method ◽  
Impedance Control ◽  
Renewable Energy Sources ◽  
Power Sharing ◽  
System Stability ◽  
Environment Simulation ◽  
Control Stability ◽  
Virtual Impedance

The concept of microgrid has been developed to realize flexible coordination control among Distributed Generation (DG) units, improve the power quality supplied to customers. The problem such as the power quality and the system stability due to the intermittency of the renewable energy sources and the fluctuating load profile. The reactive power sharing done by droop control method but reactive power is not accurately shared if there is a local load at each DG. In this paper adaptive virtual impedance control is used to improve the power control stability and sharing performance of real and reactive power sharing is compared by using MATLAB/Simulink environment. Simulation results shows the effectiveness of the proposed method is achieving load reactive power sharing and the voltage restoration is settles in less time.

METHODS ASSESSMENT QUALITY OF ACCOUNTING REPORTING AND MODELS OF THEIR MEASUREMENT

2020 ◽  
Vol 3 (3) ◽  
pp. 95-99
Author(s):  
E. H. ABU ◽  
Keyword(s):  
Internal Control ◽  
Stock Prices ◽  
Control Method ◽  
Financial Statements ◽  
Accounting Conservatism ◽  
Standardized Assessment ◽  
Accrual Quality ◽  
Indirect Measures

The article explores individual approaches used to measure and evaluate the quality of financial state-ments: standardized assessment, accrual-based models (accrual quality), Beneise models (M-Score), in-dexes - the internal control method and the degree of accounting conservatism. The reason for the great dependence on the use of indirect measures (proxies for the quality of financial statements or stock prices) is that some of the qualities of financial statements are unobservable.

Quality Improvement of the DNA extracted by boiling method in Gram negative bacteria

2017 ◽  
Vol 6 (04) ◽  
pp. 5347 ◽  
Author(s):  
Omar B. Ahmed* ◽  
Anas S. Dablool
Keyword(s):  
Dna Extraction ◽  
Control Method ◽  
Extraction Procedure ◽  
Cost Effective ◽  
High Yield ◽  
Gram Negative Bacteria ◽  
Bacterial Dna ◽  
Gram Negative ◽  
E Coli

Several methods of Deoxyribonucleic acid (DNA) extraction have been applied to extract bacterial DNA. The amount and the quality of the DNA obtained for each one of those methods are variable. The study aimed to evaluate bacterial DNA extraction using conventional boiling method followed by alcohol precipitation. DNA extraction from Gram negative bacilli was extracted and precipitated using boiling method with further precipitation by ethanol. The extraction procedure performed using the boiling method resulted in high DNA yields for both E. coli and K. pneumoniae bacteria in (199.7 and 285.7μg/ml, respectively) which was close to control method (229.3 and 440.3μg/ml). It was concluded that after alcohol precipitation boiling procedure was easy, cost-effective, and applicable for high-yield quality of DNA in Gram-negative bacteria.

Impedance Control Based Sliding Mode for Lower Limb Rehabilitation Robot

2014 ◽  
Vol 672-674 ◽  
pp. 1770-1773 ◽  
Author(s):  
Fu Cheng Cao ◽  
Li Min Du
Keyword(s):  
Dynamic Response ◽  
Sliding Mode Control ◽  
Lower Limb ◽  
Control Method ◽  
Sliding Mode ◽  
Impedance Control ◽  
Rehabilitation Robot ◽  
Active Rehabilitation ◽  
Limb Rehabilitation ◽  
Lower Limb Rehabilitation

Aimed at improving the dynamic response of the lower limb for patients, an impedance control method based on sliding mode was presented to implement an active rehabilitation. Impedance control can achieve a target-reaching training without the help of a therapist and sliding mode control has a robustness to system uncertainty and vary limb strength. Simulations demonstrate the efficacy of the proposed method for lower limb rehabilitation.

Sign in / Sign up

Export Citation Format

Share Document