Voltage stability improvement in transmission network embedded with photovoltaic systems

Power transmission systems with high proportion of motor loads may undergo voltage recovery problems in the event of a system contingency. After a disturbance, motors may stall and delay the voltage recovery process by consuming substantial amount of reactive power. It has been presented in this study that the inability of power systems to meet reactive power demand during such contingency conditions can be overcome through photovoltaic (PV) systems. With the provision of reactive power by PV systems, static and dynamic voltage stability of a local network of Saudi Electricity Company (SEC) improved by ensuring fast recovery of post-fault voltage at the motor load terminals. The improvement in voltage stability has been validated through voltage stability indices and the prevention of motor stalling cases. The performance of a large scale PV system is also compared with the fast-acting dynamic reactive power sources such as static VAR compensator (SVC) and static synchronous compensator (STATCOM).