The document discusses electrical drives and their components. An electrical drive uses an electric motor as the prime mover. The basic components of an electrical drive are the power source, motor, power processing unit, control unit, and mechanical load. The power processing unit enables flexible control of the motor speed and torque using power electronic converters. Dynamic conditions in a drive system occur during transients like starting, braking, and speed reversal. Steady-state stability is achieved when the motor torque equals the load torque at a given operating speed.
This document describes the method of fault analysis using a Z-bus matrix. It involves the following steps:
1) Drawing the pre-fault positive sequence network and obtaining the initial bus voltages
2) Forming the Z-bus matrix using the bus building algorithm
3) Calculating the fault current using Thevenin's theorem by inserting a voltage source in series with the fault impedance
4) Obtaining the post-fault bus voltages through superposition of the pre-fault voltages and voltage changes
5) Calculating the post-fault line currents based on the voltage differences and line impedances
Two examples applying this method on different systems are provided to illustrate the calculation of fault currents.
El documento describe los puentes de Wheatstone y Maxwell, que se usan para medir resistencias y parámetros de inductores desconocidos. El puente de Wheatstone consiste en cuatro ramas resistivas conectadas en forma de diamante, y permite calcular una resistencia desconocida a partir de tres resistencias conocidas. El puente de Maxwell utiliza una configuración similar con una inductancia y un condensador para medir la inductancia y resistencia en serie de un inductor. Se presentan ejemplos numéricos de cálculos usando ambos tipos de puentes.
Load flow studies analyze the steady state operation of a power system by determining voltage magnitudes and angles, as well as active and reactive power flows. The key purposes of load flow analysis include designing, planning, and optimizing the operation of a power system. The analysis models each bus in the system where generators, transmission lines, and loads connect. Buses are classified based on which two of four parameters - voltage magnitude, voltage angle, active power, and reactive power - are specified as inputs. Load flow equations are then solved to calculate the unknown parameters.
P di regenerative acceleration generator (re genx) 2013 patent disclosureThane Heins
This document provides a disclosure for a regenerative acceleration generator patent. It describes improvements to electrical generator efficiency by utilizing a Regenerative Acceleration (ReGen-X) coil design. The ReGen-X coil is able to delay current flow until the generator's rotor reaches top dead center, where inductive reactance is minimized. This allows the coil's magnetic field to assist rather than resist the rotor's motion, increasing efficiency by reducing the torque needed from the prime mover. The document provides background on conventional generator operation and explains how the ReGen-X coil design functions to reverse the decelerating effects of armature reaction through delayed current flow and flux harvesting between multiple coils.
Este documento explica los conceptos de potencia eléctrica, factor de potencia y cómo mejorar el factor de potencia en una instalación industrial. Define las potencias activa, reactiva y aparente, y cómo se relacionan a través del triángulo de potencia. Explica que un bajo factor de potencia aumenta los costos para la industria y la compañía eléctrica, y que se puede mejorar mediante el uso de condensadores o motores síncronos para compensar la potencia reactiva.
The document discusses the output equation of transformers. It explains that the voltage induced in a transformer winding is determined by factors like the number of turns and the source frequency. It also describes components of a single-phase and three-phase transformer like the primary and secondary windings contained in the transformer window. Equations are provided for calculating the copper area required based on current density and turns ratio between windings.
The document discusses load flow studies and the Gauss-Siedel method for solving power flow equations. Load flow studies calculate voltage drops, bus voltages, and power flows under various conditions to determine if voltages remain within limits and equipment is not overloaded. The Gauss-Siedel method iteratively solves power flow equations represented by a non-linear algebraic equation using the bus admittance matrix and known real and reactive power values at buses to calculate unknown bus voltages until converging on a solution. An example applies the Gauss-Siedel method with an acceleration factor to a three bus system to calculate voltages after the first iteration.
Objective Electrical Electronics Engineering Questions and AnswersMostafizur Rahman
The document contains 50 multiple choice questions and answers related to electrical engineering. It covers topics such as transformers, motors, generators, transmission lines and electrical machines. Some key details include:
- Questions test knowledge of induction motors, synchronous motors, transformers, DC machines and other core electrical engineering topics.
- Sample questions include the speed of a rotor under different conditions, voltage regulation calculations, motor pole numbers based on speed, and components of machines like capacitors in motors.
- The answers provided explain the conceptual reasoning behind each multiple choice selection to help understand the principles.
The document discusses electrical drives and their components. An electrical drive uses an electric motor as the prime mover. The basic components of an electrical drive are the power source, motor, power processing unit, control unit, and mechanical load. The power processing unit enables flexible control of the motor speed and torque using power electronic converters. Dynamic conditions in a drive system occur during transients like starting, braking, and speed reversal. Steady-state stability is achieved when the motor torque equals the load torque at a given operating speed.
This document describes the method of fault analysis using a Z-bus matrix. It involves the following steps:
1) Drawing the pre-fault positive sequence network and obtaining the initial bus voltages
2) Forming the Z-bus matrix using the bus building algorithm
3) Calculating the fault current using Thevenin's theorem by inserting a voltage source in series with the fault impedance
4) Obtaining the post-fault bus voltages through superposition of the pre-fault voltages and voltage changes
5) Calculating the post-fault line currents based on the voltage differences and line impedances
Two examples applying this method on different systems are provided to illustrate the calculation of fault currents.
El documento describe los puentes de Wheatstone y Maxwell, que se usan para medir resistencias y parámetros de inductores desconocidos. El puente de Wheatstone consiste en cuatro ramas resistivas conectadas en forma de diamante, y permite calcular una resistencia desconocida a partir de tres resistencias conocidas. El puente de Maxwell utiliza una configuración similar con una inductancia y un condensador para medir la inductancia y resistencia en serie de un inductor. Se presentan ejemplos numéricos de cálculos usando ambos tipos de puentes.
Load flow studies analyze the steady state operation of a power system by determining voltage magnitudes and angles, as well as active and reactive power flows. The key purposes of load flow analysis include designing, planning, and optimizing the operation of a power system. The analysis models each bus in the system where generators, transmission lines, and loads connect. Buses are classified based on which two of four parameters - voltage magnitude, voltage angle, active power, and reactive power - are specified as inputs. Load flow equations are then solved to calculate the unknown parameters.
P di regenerative acceleration generator (re genx) 2013 patent disclosureThane Heins
This document provides a disclosure for a regenerative acceleration generator patent. It describes improvements to electrical generator efficiency by utilizing a Regenerative Acceleration (ReGen-X) coil design. The ReGen-X coil is able to delay current flow until the generator's rotor reaches top dead center, where inductive reactance is minimized. This allows the coil's magnetic field to assist rather than resist the rotor's motion, increasing efficiency by reducing the torque needed from the prime mover. The document provides background on conventional generator operation and explains how the ReGen-X coil design functions to reverse the decelerating effects of armature reaction through delayed current flow and flux harvesting between multiple coils.
Este documento explica los conceptos de potencia eléctrica, factor de potencia y cómo mejorar el factor de potencia en una instalación industrial. Define las potencias activa, reactiva y aparente, y cómo se relacionan a través del triángulo de potencia. Explica que un bajo factor de potencia aumenta los costos para la industria y la compañía eléctrica, y que se puede mejorar mediante el uso de condensadores o motores síncronos para compensar la potencia reactiva.
The document discusses the output equation of transformers. It explains that the voltage induced in a transformer winding is determined by factors like the number of turns and the source frequency. It also describes components of a single-phase and three-phase transformer like the primary and secondary windings contained in the transformer window. Equations are provided for calculating the copper area required based on current density and turns ratio between windings.
The document discusses load flow studies and the Gauss-Siedel method for solving power flow equations. Load flow studies calculate voltage drops, bus voltages, and power flows under various conditions to determine if voltages remain within limits and equipment is not overloaded. The Gauss-Siedel method iteratively solves power flow equations represented by a non-linear algebraic equation using the bus admittance matrix and known real and reactive power values at buses to calculate unknown bus voltages until converging on a solution. An example applies the Gauss-Siedel method with an acceleration factor to a three bus system to calculate voltages after the first iteration.
Objective Electrical Electronics Engineering Questions and AnswersMostafizur Rahman
The document contains 50 multiple choice questions and answers related to electrical engineering. It covers topics such as transformers, motors, generators, transmission lines and electrical machines. Some key details include:
- Questions test knowledge of induction motors, synchronous motors, transformers, DC machines and other core electrical engineering topics.
- Sample questions include the speed of a rotor under different conditions, voltage regulation calculations, motor pole numbers based on speed, and components of machines like capacitors in motors.
- The answers provided explain the conceptual reasoning behind each multiple choice selection to help understand the principles.
Datakommunikasjon dispersjon sven åge eriksen sven age eriksen Fagskolen Telemark singelmodus multimodus fiber transmisjonsmedier analoge digitale signaler tvinnet parkabel koaksialkabel koder nrz manchester ami kode modulasjon demodulasjon modem
Datakommunikasjon Elektronisk kommunikasjon sven åge eriksen fagskolen telemark LAN WAN www world wide web modem graham bell samuel morse local area network wide area nettwork modem telstar
5. P1 = S · cos Φ = 𝟑 · U · I · cos Φ (3-fase effekt)
P1=P2/ η
Avgitt motoreffekt P2 på
motorakselen er oppgitt
på merkeskiltet.
6. - 3-fas strømtrekk fra nettet: I = S / 𝟑 · U
- 3-fas tilsynelatende effekt S 𝐒 = 𝟑 · U · I
- 3-fas tilsynelatende effekt S S = P1 / cos Φ
- Reaktiv effekt Q Q = S · sin Φ
- Aktiv effekt P1 P1=P2/ η
- Aktiv effekt P1: P1 = S · cos Φ = 𝟑 · U · I · cos Φ
- Avgitt motoreffekt P2 Står på merkeskilt
- Effektfaktor cos Φ og effekttrekant.
- Virkningsgrad: η (eta) = P2 / P1
12. Effekt, ytelse, omsatt energi per tidsenhet.
I fysikken blir energi definert som evne til å utføre
arbeid. Effekt blir da et uttrykk for tempoet arbeidet utføres i. Hvis
man heiser en last en meter opp, blir forbruket av energi det
samme uavhengig av hvilket tempo arbeidet utføres i, men mer
effekt kreves hvis arbeidet skal utføres på kortere tid.
I praksis blir begrepene energi og effekt også benyttet om bruk
av avledede energiformer som varmeenergi og elektrisk energi.
Målenhetener imidlertid den samme. I SI-systemet måles
effekten i watt [W] (oppkalt etter James Watt) der en watt tilsvarer
en joule [J] per sekund [s].
1 W = 1 J/s
https://snl.no/effekt/energi
13.
14. Effektfaktoren cos Φ beskriver hvor god f.eks en
trafo eller motor er til å omsette tilsynelatende effekt S om
til aktiv effekt P1.
15. Spørsmål:
Hva dimensjonerer du er elektrisk anlegg i forhold til,
tilsynelatende effekt S eller tilført aktiv effekt P eller avgitt
motoreffekt P2 ut på motoraksel ?
S = 𝟑 · U · I (tilsynelatende effekt)
P= 𝟑 ·U·I· cos Φ (tilført aktiv effekt)
𝟑 er med i formelen ved 3-fas, men ikke ved en-fas.
16. Svar på spørsmål:
Hva dimensjonerer du er elektrisk anlegg i forhold
til, tilsynelatende effekt S eller tilført aktiv effekt P ?
Det elektriske anlegget må dimensjoneres iht
S = 𝟑 · U · I (tilsynelatende effekt)
17.
18. Side 142
P = P1
Virkningsgraden η(eta) sier hvor
god motoren er til
å omsette tilført aktiv
effekt P1 om til avgitt
effekt P2 ut på
motorakselen
19. Virkningsgraden η er forholdet mellom avgitt
effekt / merkeeffekt P2 og tilført effekt P1.
P = P1
Noe av den avgitt effekten
taper vi og den går bl.a til
varme, vibrasjon og lyd.
20. Det er alltid et tap i en motor, derfor er η alltid mindre enn 1
21. Virkningsgrad: η (eta)
Du har regnet ut at virkningsgraden til en
motor er 1,05.
Er dette et greit svar ?
Hva slags maskiner virkningsgrad
større enn 1 ?
24. Tilsynelatende 3-fas effekt: S = 𝟑 · U · I
Tilført aktiv 3-fas effekt: P1 = 𝑺 · cos Φ
Tilført aktiv 3-fas effekt: P1 = 𝟑 · U · I · cos Φ
Merkeeffekt: P2 = 𝟑 · U · I · cos Φ · η
P2 er den effekten vi kan ta ut på motorakselen !
Virkningsgrad: η = P2 / P1
P1 = P2 / η
32. AKTIV (P) OG REAKTIV EFFEKT (Q)
Side 138
P = AKTIV EFFEKT = NYTTIG EFFEKT ENHET: W
Q = REAKTIV EFFEKT = UNYTTIG EFFEKT ENHET: var
S = TILSYNELATENDE EFFEKT ENHET: VA
33. AKTIV (P) OG REAKTIV EFFEKT (Q)
Side 140
P = AKTIV EFFEKT = NYTTIG EFFEKT ENHET: W
Q = REAKTIV EFFEKT = UNYTTIG EFFEKT ENHET: var
S = TILSYNELATENDE EFFEKT ENHET: VA
42. Oppgave b)
Først setter vi opp kjente symboler og verdier:
.
U=220V f=50Hz Cos Φ=0,8 P2=736W η=0,8
43. Oppgave b)
Først setter vi opp kjente symboler og verdier:
.
U=220V f=50Hz Cos Φ=0,8 P2=736W η=0,8
Svar: η = P2 / P1 = 0,8
P1 = P2 / 0,8 = 736W / 0,8 = 920W
Hva er tilført effekt P1 ?
45. Oppgave c)
c) Hva er tilsynelatende effekt S ?
Tilført aktiv 3-fas effekt: P1 = 𝑺 · cos Φ
46. Oppgave c)
c) Hva er tilsynelatende effekt S ?
Tilført aktiv 3-fas effekt:
P1 = 𝑺 · cos Φ
S = P1 / cos Φ
47. Oppgave c)
c) Hva er tilsynelatende effekt S ?
Tilført aktiv 3-fas effekt:
P1 = 𝑺 · cos Φ
Svar:
S = P1 / cos Φ = 920 W / 0,80 = 1150 W
48. Oppgave d)
d) Beregn strømmen som motoren trekker fra tilførselsledningene.
Tilsynelatende 3-fas effekt:
S = 𝟑 · U · I
49. Oppgave d)
d) Beregn strømmen som motoren trekker fra tilførselsledningene.
Tilsynelatende 3-fas effekt:
S = 𝟑 · U · I
I =
𝑺
𝟑 · U
50. Oppgave d)
d) Beregn strømmen som motoren trekker fra tilførselsledningene.
Tilsynelatende 3-fas effekt:
S = 𝟑 · U · I
I =
𝑺
𝟑 · U
Svar:
I =
𝑺
𝟑 · U
=
𝟏𝟏𝟓𝟎 𝑾
𝟑 · 220 V
= 3,02 A
51. Oppgave e)
e) Hva forteller virkningsgraden om motoren?
Virkningsgraden sier hvor god
motoren er til å omsette tilført aktiv
effekt P1 om til avgitt motoreffekt P2
52. Oppgave f)
f) Hvorfor er virkningsgraden til en motor alltid lavere enn 1?
Det er alltid tap i en motor,
f.eks. friksjonstap
og derfor er η alltid mindre enn 1
53. Oppgave g)
f) Hva forteller effektfaktoren om motoren?
Effektfaktoren sier hvor god motoren
er til å omsette tilsynelatende effekt S
om til aktiv effekt P1