Silicon carbide power devices are widely utilized in applications requiring high voltage and Current. Due to the limited Current capability of a single module, silicon carbide MOSFETs are frequently arranged in parallel to enhance the Current capacity of the final product. However, variations in circuit parameters or inconsistencies in semiconductor manufacturing can cause imbalances in the Current among the parallel modules, potentially resulting in performance and dependability challenges. To tackle the matter, this paper introduced the use of an active approach designed for paralleled SiC MOSFETs to resolve these unbalanced Currents. The proposed method used a Current transformer to detect the imbalance Current. Further, an active compensator is presented within a closed-loop control feedback that effectively eliminates the Current imbalance among parallell modules in a master-slave configuration. Details of Current transformer and stability of the closed-loop control are investigated. Experimental results are provided to showcase the viability and efficiency of the proposed approach.

Accurate load power sharing and voltage regulation are two critical control objectives to ensure power quality and reliable operation of islanded microgrids. Although voltage regulation can be achieved using a secondary control loop, the inaccuracy of reactive power sharing is a prominent issue due to the varying impedance of lines connected to distributed generation sources. One of the techniques for accurate sharing of reactive power is to modify the production reference voltage by the droop control method. In this paper, a control strategy is proposed to improve the accuracy of reactive power sharing among distributed generation units of islanded microgrids. The proposed control method was based on transient reactive Current injection to modify the production reference voltage of the droop control method. The reactive power-sharing error was reduced by changing the reference voltage. In addition, the proposed controller did not require a communication link between distributed generation sources for implementation. The effect of the proposed controller on the stability of the system was demonstrated using the reduced-order small-signal model. To evaluate the performance and effectiveness of the proposed control strategy, it was implemented on an islanded microgrid consisting of three distributed generation units. The simulation results showed the proper performance and efficiency of the proposed method.

Input-Parallel Output-Parallel DC-DC converters are convenient for high voltage and high Current applications. One important goal of this type connection is to power-share and reduce circulating Current between the converters. Therefore, control methods for power-sharing between converters should be used when the parameters mismatch. In this paper, a configuration comprising two DC-DC common grounded Z-source converters with Input-Parallel Output-Parallel connections is presented, which common grounded Z-source converter have advantages over similar converters. This study proposes two control strategies: (1) a decentralized inverse-droop control, (2) a general control strategy. Inverse-droop control is a simple method and does not need any communication between parallel converters. In the general control strategy, each converter is self-contained, and no external controller is required for achieving input/ Output Current sharing, and a few wires are needed to create the entire system. The simulation results of an Input-Parallel Output-Parallel system comprising two common grounded Z-source converters are evaluated for investigating effectiveness of general control and inverse-droop control. It reported performance of the general control method to be better than the decentralized inverse-droop control method, which enhances the stability and dynamic characteristics of the system. The validity of the two control strategies has been studied through MATLAB simulation and the results were satisfactory.

Parallel connection of two or even more single-phase inverter modules is a successful solution to increase the reliability and the efficiency of an inverter at moderate power levels. Stable operation and proper Current sharing among parallel inverter modules is a key issue, especially when they are connected to a common load through unequal output filter impedances. In this paper, a new formulation and consequently a proper Current sharing control algorithm for parallel connected inverter modules with the possibility of unequal filter impedances is proposed. Also a dual-loop voltage control with the filter Current as the inner loop feedback signal, considering the effect of digital control delay, is adopted. The controller parameters are designed according to a frequency domain analysis. Finally, theoretical achievements are confirmed by experimental test results on a test rig with two 250 W parallel connected single phase inverters.

Authorization systems are an important part of security systems that are responsible for protecting resources. With the increasing number of users in organizations, managing the authorization infrastructure has become increasingly time-consuming and error-prone and misconfiguration of policies has reduced the effectiveness of these systems. Researchers recommend dynamic access control methods as an effective way to issue licenses in these systems. Since the sources of decision making in these methods are the defined policies and user records, there are no special restrictions for new users and these methods face the problem of cold start. In this paper, to solve this limitation, the concepts of trust and I-sharing are used, and a new method for improving the Self-Aaptive Authorization Framework (SAAF) called ISAAF is presented. ISAAF is a framework for self-adaptive control of authorization systems using the MAPE-K autonomous reference model, which estimates the trust of new users using the trust of users with whom they have common features. I-sharing gr

A parallel connection of Buck converters improves system reliability and efficiency. However, the open circuit fault, load, and supply voltage uncertainties, and interactions among the converters increase the complexity of output voltage control and balanced Current sharing. Thus, in this paper, first, a decentralized backstepping sliding mode control strategy is designed to meet such challenges. However, this controller is quite conservative since the uncertainties and interaction bounds are not known. Moreover, the sliding mode based controllers suffer from chattering phenomena which limits the practical applications. Therefore, a decentralized adaptive backstepping control strategy with wavelet neural network approximators is proposed. This strategy reduces the chattering and approximates the uncertainties and interactions by replacing the switching terms with wavelet neural networks. To show the effectiveness of the proposed controller, different numerical simulations have been performed in the presence of reference voltage changes, load, supply voltage variations, and open circuit faults.

The purpose of this study is to evaluate the situation of knowledge sharing among faculty members and identify the effective factors of theory of planned behavior in the conduct and knowledge sharing intention. This research is a descriptive survey. The research population includes all full-time faculty members of Mashhad Branch of Islamic Azad University, totalling 435 at the time of the research conduction. Of these people, 231 were chosen as sample by the use of Morgan table and stratified random sampling technique proportionate to the number of the members of each faculty. A questionnaire was used as the instrument for data collection in this research. Single-sample t-tests, correlation, regression and descriptive statistics were used for data analysis. T-test results revealed that knowledge sharing among faculty members, except the knowledge power, has a favorable level in all elements. Among all research variables (except for the components of the power of knowledge) positive relationship was observed. sharing intention had the greatest role in explaining the knowledge sharing behavior and attitude toward knowledge sharing had the greatest role in explaining knowledge sharing intention.