# ENTEC2

Uitwerking vraag 1

• 50Hz=> 50 keer per seconde, dus 50*60 keer per minuut, dus pp = 3000/375 = 8 poolparen
• S= 2500, dus P=2500/0.9, ω=2 π * 375/60 = 39.25 rad/s, dus koppel is P/ω=57.3
• 0 watt
• spanning, freq en fase
• max spanning generator + max spanning net, dus 230rms + 230rms of 326+326 top-top als de spanningenn 180 uit fase zijn.
• dempen van oscillaties en helpen bij aanlopen

Uitwerking tentamen ENTEC2 vraag2
antwoord vraag 2a = P=3*(230*230/Xd)sin(lasthoek)=3*(230*230/26.45)*1=6000

## Oefeningen die we klassikaal gedaan hebben: Synchronous machine

Let op!
In het rekenvoorbeeld wordt de lasthoek via P en S bepaald, dat kan alleen als je Xd=1 p.u. hebt, dus het uitgerekende getal. In alle andere gevallen zul je echt de formule P=3(Up*Us/Xd)*sin(lasthoek) moeten nemen.

# ELENT2

Uitwerking tentamen Elent2

## Oefeningen die we klassikaal gedaan hebben:

In case of a three-phase load, enter only one-third of the load in the calculation, as we are calculating current and compensation of one phase only
If the compensation capacitors are in wye, use the Line-Neutral voltage for the calculation of the capacitor values
If the compensation capacitors are in delta, use the Line-Line voltage for the calculation of the capacitor values Cos(ϕ) compensation of single phase inductive load

Cos(ϕ) compensation of inductive load with 100m cable

Cos(ϕ) compensation of 3-phase 21kW inductive load with 25 meter cable

## Transformator modellen

Transformer, no-load and short circuit parameter determination

Equivalent model of the transformer Winding ratio = n
Uprimary / Usecondary
Equivalent model of the transformer where the winding ration is omitted, the secondary Ls and Rs are transformed with n2 to the primary side The resistor or inductor on the secondary side are now n2 times larger. This circuit is used to determine the parameters of the transformer in the open-circuit and in the short-circuit test.
Equivalent model of the transformerfor the no-load measurement: Open Circuit [oc] Use the nominal primairy voltage during measurement and measure Uocprimary[V]=Unom, Iocprimary[A] and Pocprimary[Watt]
Measure the magnetizing current and iron loss
Equivalent model of the transformerfor the Short-circuit measurement: Short Circuit [sc] Use the nominal primary current during measurement and measure Uscsecondary[V], Iscsecondary[A]=Inom and Pscsecondary[Watt]
Measure the leakage inductance and winding resistance. For simplicity the winding resistance and leakage inductance of the primary and secondary side are considered equal.
Note!
A resistor or inductor on the secondary side is measured at the primary side n2 times larger.
Rcu=Rp + n2 * Rs
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