Voltage Stability in Power Systems with Different Wind Energy Generating Capacities

Abstract

Voltage stability depends on how the variations in Q and P affect the voltages at the load bus. The influence of reactive power characteristics of devices at the receiving end is more apparent in a Q-V relationship. It shows the sensitivity and variation of bus voltages with respect to reactive power injections or absorptions. This point also defines the minimum reactive power requirement for a stable operation. And, if there is any increase in added active power of distributed generation units will result an increase in voltage during normal operating conditions.

The study in this chapter were performed on the 15-bus and the IEEE 72-bus systems.

Each model is integrated with WTGs as DGs by different penetration levels (5% - 30%)in order to study the effect of WTGs compensation in the system. The load perturbation isdonetothe selected low voltage profile buses from the two networks.The P-V and Q-V Characteristics are presented.The voltage stability study is performed.

As clear from presenting and discussing the results, the critical voltage became farther when integrating the system with wind turbine generators at optimized locations. Not only avoiding the critical voltage is done, but also, the loading of the system is maximized.

Voltage stability can be evaluated as the VSM determination. VSM determination is done through the P-V curve. As a result of integrating WTGs into the system with increasing penetration levels, voltage stability of the system is enhanced and the overall system performance.