Sökning: "switching frequency"

Visar resultat 16 - 20 av 181 avhandlingar innehållade orden switching frequency.

1. 16. Power Quality Disturbances and Protective Relays

   Författare :Fan Wang; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; overcurrent relays; component switching; frequency deviation; power system disturbance; protection algorithms; power quality; digital protective relays; impedance relays;

   Sammanfattning : This thesis combines knowledge from two areas: power quality and power system protection. Power quality concerns the effect of voltage disturbances on end-user equipment and of current disturbances on network components. Power system protection concerns the detection of faults in the system from measured voltages and currents. LÄS MER

3. 17. Layered optical networks : implications to switching and transmission

   Författare :Stefan Larsson; KTH; []
   Nyckelord :;

   Sammanfattning : With the aim of supporting and enhancing high-capacitycommunication networks, such as telephony, Internet and others,this work has investigated:· transmission gains withtime-slotted optical communication, · performance ofoptical add/drop multiplexers (OADMs) and optical crossconnects(OXCs), · OXC networks serving Internet Protocol(IP)-routers, · packet hop reductions in IP-controlledoptical networks, · a simple optical neighbour discoverymethod, · economics of complementing a client network withan optical express layer.Time-slotting was shown to enable bi-directionaltransmission at the same frequency and multiwavelengthtransmission over dispersion-shifted fibre. LÄS MER

4. 18. Self-Switching Diodes for Zero-Bias Terahertz Detection

   Författare :Andreas Westlund; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; self-switching diode; noise-equivalent power; SSD; graphene; zero-bias; InAs; InGaAs; terahertz; detector;

   Sammanfattning : The self-switching diode (SSD) has been investigated as a potential terahertz detector in recent years. The SSD accomplishes a non-linear current-voltage relation through a field-effect, which enables detection at zero bias from microwave up to terahertz frequencies. In this work, SSDs were realised in two new materials; InAs and graphene. LÄS MER

5. 19. High Frequency (MHz) Resonant Converters using GaN HEMTs and Novel Planar Transformer Technology

   Författare :Hari Babu Kotte; kent Bertilsson; Bengt Oelmann; Noel Shammas; Torbjörn Thiringer; Per Karlsson; Mittuniversitetet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; GaN HEMTs; MHz Frequency; Resonant Converters; Planar Transformer Technology;

   Sammanfattning : The increased power consumption and power density demands of moderntechnologies have increased the technical requirements of DC/DC and AC/DC powersupplies. In this regard, the primary objective of the power supply researcher/engineeris to build energy efficient, high power density converters by reducing the losses andincreasing the switching frequency of converters respectively. LÄS MER

7. 20. On possibilities of smart meters switching at low voltage level for emergency grid management

   Författare :Yasir Arafat; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical distribution grid; Smart grid; Remote switching; Smart meter.; Power quality; Power quality measurement;

   Sammanfattning : Smart Meter (SM) is an advanced remotely readable energy meter with two-way communication capability which measures the electrical energy in real-time or near-real-time and securely sends data to Distribution System Operator (DSO). A smart metering system is an application of SMs on a larger scale, i.e. LÄS MER