Monitoring voltage collapse margin with synchrophasors across transmission corridors with multiple lines and multiple contingencies

We use synchrophasor measurements of the complex voltage and current at both ends of multiple transmission lines that connect areas of a power system to monitor the online voltage collapse margin. A new reduction is used to reduce the multiple transmission lines to a single line equivalent and determine how to combine the synchrophasor measurements. Generator reactive power limits can be accommodated. The results show that this methodology can capture the effect of multiple contingencies inside the transmission corridors, giving awareness to the operators about the severity of contingencies with respect to voltage stability.

Notation

Admittance of line between buses and

Complex voltage at bus

Complex current injected at bus

Complex power injected at bus

Complex voltage in line between buses and

Complex current in line between buses and

Generation bus

ℓ

Load bus

PMU

Phasor measurement unit

Corridor

Transmission lines that connect areas