Essays about: "variable speed"

Showing result 16 - 20 of 143 essays containing the words variable speed.

1. 16. Investigation of Variable Speed Technology when Converting Hydropower Kaplan Turbines into Fixed Propeller Turbines

   University essay from Uppsala universitet/Institutionen för fysik och astronomi

   Author : Johannes Ansved; [2022]
   Keywords : hydropower; variable speed; kaplan; turbines; model; simulation;

   Abstract : With an evolving energy system, an increased flexibility is necessary, placing additional demand on hydropower plants. New technology, in particular full size frequency converters (FSFC) and doubly fed induction machines (DFIM), allows hydropower turbines to run at different speeds than originally designed, thus making the turbine more flexible. READ MORE

3. 17. Sensorless Control of Synchronous Machines in Python Using Signal Injection : An implementation of a High-Frequency Square-Wave Injection Algorithm on a Linear and Non-Linear Synchronous Machine Model in open-source Software Motulator

   University essay from KTH/Skolan för elektroteknik och datavetenskap (EECS)

   Author : Simon Lundberg; [2022]
   Keywords : High-frequency signal injection; Permanent Magnet Synchronous Motor; sensorless speed control; Synchronous Reluctance Machine; square-Wave injection; Fyrkantsvågsinjektering; högfrekvent signalinjektering; Permanentmagnetsmotor; sensorlös hastighetskontroll; synkron reluktansmotor;

   Abstract : The importance of accurately controlling the speed and torque of Synchronous Machines (SMs) in industry, transportation, aerospace, to name a few, can not be overstated. The driving unit to control the machines are called Variable Speed Drives (VSDs) and they can be designed in many different ways. READ MORE

4. 18. Positional differences in peak intensity periods in Swedish elite football

   University essay from Gymnastik- och idrottshögskolan, GIH/Institutionen för fysisk aktivitet och hälsa

   Author : Andreas Eronen; [2022]
   Keywords : ;

   Abstract : Introduction: Football players cover around 8-13 kilometres of running in different speeds in a match. However, the reporting of the sum or average of total distance covered fail to give an accurate picture of the most physically intense and demanding periods in matches, called “peak periods”. READ MORE

5. 19. Analysis and Performance Evaluation of a Three-phase Three-level Sparse Neutral Point Clamped Converter for Industrial Variable Speed Drives

   University essay from KTH/Skolan för elektroteknik och datavetenskap (EECS)

   Author : Pengpeng Sun; [2022]
   Keywords : Sparse Neutral Point Clamped Converter; Industrial Variable Speed Drives; Silicon IGBT; Calorimetric Measurement; Reverse Recovery Energy; Sparse Neutral Point Clamped Converter; Industriella Varvtalsstyrda Motordrifter; Silicon IGBT; Kalorimetrisk Mätning; Energi för Återhämtningsprocess;

   Abstract : This thesis project focuses on the simulation, design, hardware realization, and performance evaluation of a Three-phase Three-level (3-L) Sparse Neutral Point Clamped Converter (SNPCC) for Industrial Variable Speed Drives (VSDs). The basic operating principle of the SNPCC is briefly described based on switching functions. READ MORE

6. 20. Test-retest reliability of a newly developed instrument for measurement of force production and speed in closed kinetic chain for upper extremity : Measurements on a group of athletes with cerebral palsy and a reference group

   University essay from Gymnastik- och idrottshögskolan, GIH/Institutionen för fysisk aktivitet och hälsa

   Author : Frida Lidén; [2022]
   Keywords : Para sport; cerebral palsy; coordination; closed kinetic chain; upper extremity;

   Abstract : Aim and research questions: The aim of this master thesis was to test for test-retest reliability for a newly developed force instrument (FI) and determine if a combined effect of trial, speed and resistance exist on the variable fraction effective force (FEF) for a group of athletes with cerebral palsy (CP-group) and a reference group (AB-group).  1. READ MORE