Robustness and Stability Analysis of a Predictive PI Controller in WirelessHART Network Characterised by Stochastic Delay

As control over wireless network in the industry is receives increasing attention, its application comes with challenges such as stochastic network delay. The PIDs are ill equipped to handle such challenges while the model based controllers are complex. A settlement between the two is the PPI controller. However, there is no certainty on its ability to preserve closed loop stability under such challenges. While classical robustness measures do not require extensive uncertainty modelling, they do not guarantee stability under simultaneous process and network delay variations. On the other hand, the model uncertainty measures tend to be conservative. Thus, this work uses extended complementary sensitivity function method which handles simultaneously those challenges. Simulation results shows that the PPI controller can guarantee stability even under model and delay uncertainties

Fuzzy Adaptive Setpoint Weighting Controller for WirelessHART Networked Control Systems

Gain range limitation of conventional proportional‐integral‐derivative (PID) controllers has made them unsuitable for application in a delayed environment. These controllers are also not suitable for use in a Wireless Highway Addressable Remote Transducer (WirelessHART) protocol networked control setup. This is due to stochastic network‐induced delay and uncertainties such as packet dropout. The use of setpoint weighting strategy has been proposed to improve the performance of the PID in such environments. However, the stochastic delay still makes it difficult to achieve optimal performance. This chapter proposes an adaptation to the setpoint weighting technique. The proposed approach will be used to adapt the setpoint weighting structure to variation in WirelessHART network‐induced delay through fuzzy inference. Result comparison of the proposed approach with both setpoint weighting and proportional‐integral (PI) control strategy shows improved setpoint tracking and load regulation. For the first‐, second‐ and third‐order systems considered, analysis of the results in the time domain shows that in terms of overshoot, undershoot, rise time, and settling times, the proposed approach outperforms both the setpoint weighting and the PI controller. The approach also shows faster recovery from disturbance effect

Accurate delay analysis in prioritised wireless sensor networks for generalized packet arrival

This letter presents an accurate delay analysis in prioritised wireless sensor networks (WSN). The analysis is an enhancement of the existing analysis proposed by Choobkar and Dilmaghani, which is only applicable to the case where the lower priority nodes always have packets to send in the empty slots of the higher priority node. The proposed analysis is applicable for any pattern of packet arrival, which includes the general case where the lower priority nodes may or may not have packets to send in the empty slots of the higher priority nodes. Evaluation of both analyses showed that the proposed delay analysis has better accuracy over the full range of loads and provides an excellent match to simulation results

Performance analysis of Arithmetic Mean method in determining peak junction temperature of semiconductor device

High reliability users of microelectronic devices have been derating junction temperature and other critical stress parameters to improve device reliability and extend operating life. The reliability of a semiconductor is determined by junction temperature. This paper gives a useful analysis on mathematical approach which can be implemented to predict temperature of a silicon die. The problem could be modeled as heat conduction equation. In this study, numerical approach based on implicit scheme and Arithmetic Mean (AM) iterative method will be applied to solve the governing heat conduction equation. Numerical results are also included in order to assert the effectiveness of the proposed technique

Development of an Adaptive Controller for Gridconnected Power Electronic Converter

Power electronics converter (PECs) has become an attractive replacement for the conventional inverter in grid-tied photovoltaic (PV) applications. This is due to improved the transient performance and provided better power quality. In this paper, an improved controller and a novel topology for a PEC is proposed. In this paper, an improved controller and a novel topology for a PEC is proposed. The proposed PEC topology is based on the three-level converter and adaptive PI with a fuzzy logic controller (API-FLC). The PEC with the novel controller is designed to achieve constant DC link voltages and sinusoidal current and voltage with near unity power factor when operating in different conditions. In order to evaluate the validity of the proposed PEC, the model was simulated by MATLAB/Simulink Toolbox. The results obtained with the proposed converter gives a better dynamic performance and improved power quality compared to the conventional converter

Development of an Adaptive Controller for Gridconnected Power Electronic Converter

Power electronics converter (PECs) has become an attractive replacement for the conventional inverter in grid-tied photovoltaic (PV) applications. This is due to improved the transient performance and provided better power quality. In this paper, an improved controller and a novel topology for a PEC is proposed. In this paper, an improved controller and a novel topology for a PEC is proposed. The proposed PEC topology is based on the three-level converter and adaptive PI with a fuzzy logic controller (API-FLC). The PEC with the novel controller is designed to achieve constant DC link voltages and sinusoidal current and voltage with near unity power factor when operating in different conditions. In order to evaluate the validity of the proposed PEC, the model was simulated by MATLAB/Simulink Toolbox. The results obtained with the proposed converter gives a better dynamic performance and improved power quality compared to the conventional converter