Definition and units¶
Sign Convention¶
Generators and Loads in an AC power system can behave either like an inductor or a capacitor. Mathematically, this has two different sign conventions, either from the generator perspective or from the load perspective. This is defined by the direction of power flow from the component.
Both sign conventions are used in eDisGo depending upon the components being defined, similar to pypsa.
Generator Sign Convention¶
While defining time series for Generator
, GeneratorFluctuating
,
and Storage
, the generator sign convention is used.
Load Sign Convention¶
The time series for Load
is defined using the load sign convention.
Reactive Power Sign Convention¶
Generators and Loads in an AC power system can behave either like an inductor or a capacitor. Mathematically, this has two different sign conventions, either from the generator perspective or from the load perspective.
Both sign conventions are used in eDisGo, similar to pypsa. While defining time series for
Generator
, GeneratorFluctuating
, and
Storage
, the generator sign convention is used. This means that when
the reactive power (Q) is positive, the component shows capacitive behaviour and when the reactive power (Q) is
negative, the component shows inductive behaviour.
The time series for Load
is defined using the load sign convention. This means
that when the reactive power (Q) is positive, the component shows inductive behaviour and when the
reactive power (Q) is negative, the component shows capacitive behaviour. This is the direct opposite of the
generator sign convention.
Units¶
Variable 
Symbol 
Unit 
Comment 

Current 
I 
kA 

Length 
l 
km 

Active Power 
P 
MW 

Reactive Power 
Q 
MVar 

Apparent Power 
S 
MVA 

Resistance 
R 
Ohm or Ohm/km 
Ohm/km applies to lines 
Reactance 
X 
Ohm or Ohm/km 
Ohm/km applies to lines 
Voltage 
V 
kV 

Inductance 
L 
mH/km 

Capacitance 
C 
µF/km 

Costs 
kEUR 