The Role and Benefits of Static Var Systems in High Voltage Power System Applications

The specific role of Static Var Systems (SVS) as a form of dynamic reactive power compensation in high voltage ac power systems is described. A characteristic of the SVS which sets it apart from other forms of compensation is its extreme speed of response in adjusting its reactive power output to meet rapidly changing needs of the system. Examples [1] are given showing the benefits of SVS in suppressing load rejection overvoltages, increasing the transient stability power limit of a 500 kV radial transmission system, and in preventing a voltage collapse following a generator trip and subsequent increase in import power requirements. One example shows how the installation of a third 500 kV circuit could be avoided with the application of two SVS, with a significant savings in capital costs.