SVC CONTROL(detailed model)

I can't find how we choose the size of TCR and TSC in Static Var compensator example(detailed model)

Answer 1

[William Rose]

@Xristina,

The example description says "one 109-Mvar thyristor-controlled reactor bank (TCR) and three 94-Mvar thyristor-switched capacitor banks (TSC1 TSC2 TSC3)"

[Xristina]

My question is how it’s computed the 109MVAr and 94MVAr for TSC and TCR

[William Rose]

@Xristina,

I have only a very basic understanding of electric power transmission, so my analysis below is not 100% guaranteed correct.

The first line of the description says "This example shows the operation of a +300 Mvar/-100 Mvar Static Var Compensator (SVC)." It would be more accurate to say that three 94 Mvar TSCs provide +282 Mvar of compensation, and one TCR provides -109 Mvar of compensation. The amount of positive and negative compensation needed depends on the relative amounts of inductive and capacitive loads on the system. As different users go online and offline, the compensation needed will change. Inductive loads require capacitive compensation (TSCs). Capacitive loads require inductive compensation (TCRs). The compensation vaues of approximately +300 Mvar and -100 Mvar are not explained in this example, but may have been estimated by observing the past behavior of this system or comparable systems. Most large electrical power networks are more inductive than capacitive, due to the presence of motors and transformers in the load. Therefore it is not surprising that this example requires more capacitive compensation than reactive compensation.