[PG1995 (OP)]

Hi,

Please have a look on the attachment. Could you please help me to understand the reason for introducing the factor of "1000" is introduced in eq. 4.4 and eq. 4.5? Thank you.

[chiralSPO]

The factor of 1000 come from the change from V to kV (1 kV = 1000 V)

[PG1995 (OP)]

The factor of 1000 come from the change from V to kV (1 kV = 1000 V)

Thank you.

Eq. 4.4, Base current I_b = (1000)(MVA)_b/(kV) = (kVA)_b/(kV) A. It looks like as if "Mega" is converted into "kilo" by multiplying it by "1000" which doesn't make any sense. It looks like that 1000*Mega=kilo? Thanks.

[chiralSPO]

The factor of 1000 come from the change from V to kV (1 kV = 1000 V)

Thank you.

Eq. 4.4, Base current I_b = (1000)(MVA)_b/(kV) = (kVA)_b/(kV) A. It looks like as if "Mega" is converted into "kilo" by multiplying it by "1000" which doesn't make any sense. It looks like that 1000*Mega=kilo? Thanks.

Ah yes, you are right. On closer examination, it does appear that they multiplied by 1000 instead of dividing.

[evan_au]

This looks like a subject on power electronics?

You should learn to recognize relevant entries from the table of metric prefixes.
- M = Mega = 1 million = 10⁶
- k = kilo = 1 thousand = 10³
- These are often used for voltages and currents in power transmission lines

It is likely that you will also need to recognise smaller values as well:
- m = mili = 1/thousand = 10^-3
- μ (or u) = micro = 1/million = 10^-6
- n = nano = 1/billion = 10^-9
- These are often used for capacitances and currents in low-power circuits

You should also become familiar with how to convert between the different prefixes; when to multiply or divide by 1000 or 1000000.
See: https://en.wikipedia.org/wiki/Metric_prefix

[Colin2B]

 I would add pico p = 10^-12 Again useful for capacitance.

[PG1995 (OP)]

Thank you, everyone!