Improved Sensor Fault-Tolerant Control Technique Applied to Three-Phase Induction Motor Drive

An improved fault-tolerant control (FTC) method using mathematical functions is applied to the induction motor drive (IMD) against current sensors and speed encoder failures, which occur when the sensor is disconnected or completely damaged. The IMD with two current sensors and an encoder is speed controlled based on the field-oriented control (FOC) technique in regular operation. In this paper, an FTC unit is implemented in the FOC controller to detect and solve the sensor fault to increase the reliability of the speed control process. The measured stator currents and the feedback speed signal are integrated into the diagnosis algorithms to create a sensor fault-tolerant control function. Three diagnosis functions operating in a defined sequence are proposed for determining the health status of current and speed sensors. The FTC function performs isolation and replaces the faulty sensor signals with the proper estimated signals; then, the IMD will operate in the corresponding sensorless mode. Simulations will be performed to verify the accuracy and reliability of the proposed method under various sensor faults

Improving the Quality of Teaching Physical Education Courses at Universities

This manuscript explores the advantages and limitations of teaching physical education courses at universities and proposes strategies to enhance the quality of teaching. The advantages of improving the quality of physical education teaching include flexible selection of sports subjects, enhancing positive attitudes towards learning, continuous development and improvement of lecturers, testing and evaluation standards, and innovative teaching methods. The limitations identified are limited curriculum content, teaching plans dependent on weather conditions, limited lecturer team, and lack of motivation among some students. To enhance the quality of teaching physical education, the manuscript proposes enhancing the role and significance of physical education in universities and adjusting and improving the content of the physical education program through innovative teaching methods, such as introducing new elective subjects, adapting teaching content and methods to student needs, and promoting interdisciplinary collaboration between departments

Application of the improved four-node element MISQ24 for geometrically nonlinear analysis of plate/shell structures

In this paper the smoothed strain based four-node flat element MISQ24 with driiling degrees of freedom is extended for geometrically nonlinear analysis of plate and shell structures. The von-Karman's large deflection theory and the Total Lagrangian (TL) approach are employed in the formulation of the elements to describe small strain geometric nonlinearity with large deformations using the first-order shear deformation theory (FSDT). The predictive capability of the present models is demonstrated by comparing the present results with analytical/experimental and other numerical solutions available in the literature. Numerical examples show that the presented formulations can prevent loss of accuracy in severely distorted meshes, and therefore, are superior to those of other quadrilateral elements with inplanes rotations

An investigation of the academic consulting competence of high school teachers in Vietnam

High school students must grapple with a host of issues and encounter difficulties when studying at schools, such as peer pressure, test anxiety, cyberbullying, unhealthy relationships, psychological distress, depression and possibly domestic issues. These obstacles create the need for academic consulting in order for high school students to develop essential skills and then solve problems. This study aims to examine the high school teachers' perceptions and the quality of academic consulting competence in the Vietnamese educational context. This study surveyed 1089 high school students and 289 teachers in Ha Noi and Ho Chi Minh City in Vietnam with the 43-item questionnaire. The main results showed that academic consulting competence had been noticed and trained professionally for high school teachers. Additionally, both students and high school teachers recognized the essential role of high school teachers' academic consulting competence in educational settings

Nitrite metabolism of several bacterial strains isolated from abattoir and swine wastewater after biogas treatment

In nitrogen treatment with biological methods, nitrite metabolism is an intermediate process that facilitates other processes involving different bacteria strains. In this study, we isolated two nitrite-oxidising bacteria strains from abattoir wastewater and wastewater from biogas tanks of an industrial pig farm in Ha Tinh province. The bacteria strains grow, develop, and metabolise nitrite at pH 6–8 and 30–37 °C. The samples with the nitrite concentration up to 750 mg·L–1 were oxidised within four days of incubation, and the nitrite metabolism rate was proportional to the concentration of nitrite tested. Under severe conditions (salinity up to 3% NaCl, a low dissolved oxygen level of 0.1 mg·L–1), the two isolated bacterial strains exhibited their effective growth and nitrite metabolism capacity. The results enrich the database of nitrite-oxidising bacteria and are prospective in wastewater treatment

Pulse-width modulation direct torque control induction motor drive with Kalman filter

The paper deals with application of Kalman filter in induction motor drive using pulse-width modulation direct torque control (PWM-DTC). In the first part, the conventional PWM-DTC drive is described and Kalman filter is utilized to filter components of stator current vector those are assumed to be disturbed by white noise. The second part contains simulation results that are obtained in different cases of load torque, process and measurement noise covariances. The integral time absolute error (ITAE) performance index, undershoot, ripple of important quantities are used to compare the conventional drive structure and proposed drive structure with Kalman filter. The simulation results confirm the expected dynamic response of the proposed structure