**3. FACTS modeling**

Since their apparition, many models of FACTS devices are proposed by researchers to improve the power quality delivered to consumer, the proposed models are integrated in the standard power flow problem, and to the optimal power flow problem. The objective of this section is to investigate the integration of many types of FACTS controllers (shunt, series, and hybrid Controllers) in a practical electrical network to enhance the power quality.

### **3.1 Static VAR Compensator (SVC)**

The steady-state model proposed by Acha et al. (Achat et al., 2004) is used here to incorporate the SVC on the standard power flow problems based Newton Raphson. This

Fig. 15. Static var Compensator (SVC)

In Fig. 14 combined shunt and series controllers inject current into the system with the shunt part of the controller and voltage in series in the line with the series part of the controller. However, when shunt and series controllers are unified, there can be a real power exchange

between the series and shunt controllers via the power link (Achat et al., 2004).

⊕ *Qij* +Q -Q

and hybrid Controllers) in a practical electrical network to enhance the power quality.

Since their apparition, many models of FACTS devices are proposed by researchers to improve the power quality delivered to consumer, the proposed models are integrated in the standard power flow problem, and to the optimal power flow problem. The objective of this section is to investigate the integration of many types of FACTS controllers (shunt, series,

The steady-state model proposed by Acha et al. (Achat et al., 2004) is used here to incorporate the SVC on the standard power flow problems based Newton Raphson. This

I

*Shunt Transformer* 

*Filter TSC TCR* 

Dc Power Link

C L

*Voltage Control Power Control*

P, Q

*Bus J* 

*Vr*

*Bus i* 

⊕ *Pij*

**3. FACTS modeling** 

<sup>−</sup> *Pij* <sup>−</sup> *Qij*

Fig. 14. Unified series-shunt Controller

**3.1 Static VAR Compensator (SVC)** 

L

Fig. 15. Static var Compensator (SVC)

C

model is based on representing the controller as a variable impedance, assuming an SVC configuration with a fixed capacitor (FC) and Thyristor-controlled reactor (TCR) as depicted in Fig. 15, the controlling element is the Thyristor valve. The thyristors are fired symmetrically, in an angle control range of 90 to 180 with respect to the capacitor (inductor) voltage. Fig. 16 shows the two SVC models basic representation.

Fig. 16. Two SVC models representation
