Process monitoring based on Concurrent Projection to Latent Structures (CPLS) has been proposed recently as an efficient process monitoring tool to detect the input-relevant and output-relevant ...faults. In this paper, a novel multimode process monitoring approach is proposed to introduce external analysis into the CPLS monitoring framework. The process variables are divided into external variables, main variables and the output variables. The mode change is detected by monitoring the variation of the external variables through a mode-detection CPLS. The prediction of the main and quality variables by external variables is done by a PLS. After the influence of the external variables is removed from the main and quality variables, another process-monitoring CPLS is built to detect the main-variable-relevant faults and quality-variable-relevant faults. The proposed approach is illustrated with a simulation process.
This paper introduces electronically tunable multiple-mode universal biquadratic circuits employing operational trans-conductance amplifiers (OTAs) and grounded capacitors. The basic current-mode ...circuit configuration is obtained from a second-order integrator loop structure consisting of loss-less integrators. The multiple-mode biquadratic circuits are constructed with additional OTAs to the current-mode one. The circuits can realize low-pass, bandpass, high-pass, band-stop and all-pass transfer functions by suitably choosing the input and output terminals without any component matching conditions. Additionally, the circuit parameters ω 0 , Q and H can be set orthogonally or independently through adjusting the bias currents of the OTAs. The biquadratic circuit is verified by using PSPICE simulation program.
Increase of DC-compatible loads, popularization of renewable distributed generations (DGs) and development of power electronic converters have boosted the applications of DC microgrid in household ...level. Proper control algorithms for autonomous operation of DC microgrid which coordinates the operation of energy storages, sources and loads become the key challenge. Comparing with centralized energy management system, distributed control eliminates communication link, thus system response speed and reliability could be enhanced. DC-bus signaling (DBS) in which the bus voltage is regarded as global indicator for system power balance is an effective solution for power sharing. Bus voltage band is divided into few sub-regions around the nominal value. Various elements are prioritized based on system control objectives and scheduled to operate with different mode in respective sub-region. Bus voltage variation induced by power supply/demand difference activates operation mode change of system elements autonomously. A lab-scale DC microgrid with integration of modular solar Photovoltaic (PV) system, battery energy storage (BES) and DC loads was developed to verify the feasibility and effectiveness of proposed control algorithm.