scholarly journals Current Decoupling and Controller Design for Induction Motors Based on Neutral Delay System

2019 ◽  
Vol 256 ◽  
pp. 04006
Author(s):  
Guofang Wang ◽  
Yuedou Pan ◽  
Yongliang Li
Keyword(s):  
Time Delay ◽  
System Performance ◽  
Induction Motors ◽  
Neutral Current ◽  
Delay System ◽  
Decoupling Control ◽  
Time Delay System ◽  
Control Delay ◽  
Stator Current ◽  
Current Controller

In the AC power transmission system, in order to reduce the loss of switching devices, the switching frequency of the traction converter is generally low, and a large digital control delay will occur, which will aggravate the cross coupling between the excitation component and the torque component of the stator current of the motor, resulting in poor system performance. In order to solve this problem, based on the theory of neutral time-delay system and the rotor flux-oriented model of induction motors, the mathematical model of neutral-type time-delay system for induction motors is established, and a neutral current controller with current decoupling control is designed. The decoupling control of the stator current reduces the influence of the digital control delay on the system performance. The simulation results show that the induction motor system with a neutral current controller has the advantages of small coupling, rapid response, and strong robustness. Explains the feasibility of the designed current controller.

The Use of Response Prompting and Frames for Teaching Sentence Writing to Students With Moderate Intellectual Disability

2016 ◽  
Vol 33 (3) ◽  
pp. 142-149 ◽  
Author(s):  
Robert Pennington ◽  
Allison Flick ◽  
Kendra Smith-Wehr
Keyword(s):  
Intellectual Disability ◽  
Time Delay ◽  
Delay System ◽  
Constant Time Delay ◽  
Intervention Package ◽  
Time Delay System ◽  
Moderate Intellectual Disability ◽  
System Of Least Prompts ◽  
Response Prompting ◽  
Multiple Probe

In the current study, we examined the effects of response prompting strategies (i.e., constant time delay, system of least prompts) and frames on sentence writing for three participants, ages 7 to 12, with moderate intellectual disability. We used a concurrent multiple probe across behaviors design to evaluate the efficacy of the intervention package and posttest probes to assess generalized responding to untrained stimulation. During intervention, the teacher taught two students to construct sentences using selection-based software and another to generate handwritten responses across three different writing frames (i.e., I want _________, I see _____, The _____ is ______). Our findings suggest that the package was effective and produced variable levels of maintenance and generalized responding for all three participants.

Stabilizing Gain Regions of PID Controller for Time Delay Systems

2013 ◽  
Vol 313-314 ◽  
pp. 432-437
Author(s):  
Fu Min Peng ◽  
Bin Fang
Keyword(s):  
Stability Analysis ◽  
Time Delay ◽  
Pid Controller ◽  
Delay System ◽  
Nyquist Plot ◽  
Delay Systems ◽  
Time Delay Systems ◽  
Frequency Range ◽  
Time Delay System ◽  
Key Points

Based on the inverse Nyquist plot, this paper proposes a method to determine stabilizing gain regions of PID controller for time delay systems. According to the frequency characteristic of the inverse Nyquist plot, it is confirmed that the frequency range is used for stability analysis, and the abscissas of two kind key points are obtained in this range. PID gain is divided into several regions by abscissas of key points. Using an inference and two theorems presented in the paper, the stabilizing PID gain regions are determined by the number of intersections of the inverse Nyquist plot and the vertical line in the frequency range. This method is simple and convenient. It can solve the problem of getting the stabilizing gain regions of PID controller for time delay system.

Sign in / Sign up

Export Citation Format

Share Document