Switching Research Papers - Academia.edu (original) (raw)

In this study, direct torque control (DTC) of induction motor is evaluated based on space vector modulation (SVM). DTC is a method to control machine with utilizing torque and flux of motor controlled. The torque and current ripple are... more

In this study, direct torque control (DTC) of induction motor is evaluated based on space vector modulation (SVM). DTC is a method to control machine with utilizing torque and flux of motor controlled. The torque and current ripple are occurred in the conventional DTC. Reason of undesired torque and current ripple is low number of voltage vectors applied to the motor controlled by the conventional DTC technique. SVM-DTC is a technique to reduce the ripple. SVM techniques have several advantages that are offering better DC bus utilization, lower torque ripple, lower total harmonic distortion in the AC motor current, lower switching loss, and easier to implement in the digital systems. Simulation results from the classical and improved DTC are presented and compared. Result shows that the torque, flux linkage and stator current ripple are decreased with the improved DTC.

Power failure or outage in general does not promote development to public and private sector. The investors do not feel secure to come into a country with constant or frequent power failure. These limit the development of industries. In... more

Power failure or outage in general does not promote development to public and private sector. The investors do not feel secure to come into a country with constant or frequent power failure. These limit the development of industries. In addition there are processes that cannot be interrupted because of their importance, for instance surgery operation in hospitals, transfer of money between banks and lots more. This paper presents the design and construction of an automatic power changeover switch that switches power supply from public supply to generator once there is public power supply outage and it does this automatically. This is achieved by the use of integrated circuits that have timing abilities and relays to effect switching.

This paper presents a simple dynamic overmodulation method to obtain a quick dynamic torque response in Direct Torque Control with constant switching frequency (will be referred as DTC-CSF) induction machines. A fast dynamic torque... more

This paper presents a simple dynamic overmodulation method to obtain a quick dynamic torque response in Direct Torque Control with constant switching frequency (will be referred as DTC-CSF) induction machines. A fast dynamic torque control can be achieved by applying a voltage vector that produces the largest tangential flux component during the transient condition. To perform this, the flux error status produced from the flux hysteresis comparator is modified before it is being fed to the look-up table, during dynamic condition. The effects of different switching and operating condition on dynamic torque performance are presented. The main benefit of the proposed method is its simplicity since only minor modification is made to the basic DTC hysteresis-based structure.

Research indicates ongoing development of prospective memory as well as theory of mind and executive functions across late childhood and adolescence. However, so far the interplay of these processes has not been investigated. Therefore,... more

Research indicates ongoing development of prospective memory as well as theory of mind and executive functions across late childhood and adolescence. However, so far the interplay of these processes has not been investigated. Therefore, the purpose of the current study was to investigate whether theory of mind and executive control processes (specifically updating, switching, and inhibition) predict prospective memory development across adolescence. In total, 42 adolescents and 41 young adults participated in this study. Young adults outperformed adolescents on tasks of prospective memory, theory of mind, and executive functions. Switching and theory of mind predicted prospective memory performance in adolescents.

Is there a single executive process or are there multiple executive processes that work together towards the same goal in some task? In these experiments, we use counter switching and response inhibition tasks to examine the neural... more

Is there a single executive process or are there multiple executive processes that work together towards the same goal in some task? In these experiments, we use counter switching and response inhibition tasks to examine the neural underpinnings of two cognitive processes that have often been identified as potential executive processes: the switching of attention between tasks, and the resolution of interference between competing task responses. Using functional magnetic resonance imaging (fMRI), for both event-related and blocked design tasks, we find evidence for common neural areas across both tasks in bilateral parietal cortex (BA 40), left dorsolateral prefrontal cortex (DLPFC; BA 9), premotor cortex (BA 6) and medial frontal cortex (BA 6/32). However, we also find areas preferentially involved in the switching of attention between mental counts (BA 7, BA 18) and the inhibition of a prepotent motor response (BA 6, BA 10), respectively. These findings provide evidence for the separability of cognitive processes underlying executive control.