The Comparison of Potential Financial Benefits from the Installation of SC and Controllable SC under Restructuring Environment

While the dynamic performance of thyristor-controlled series capacitor is well recognized, the use of series capacitors (SC) and controllable series capacitor (CSC) for the improvement of transfer capability has also drawn plenty of research interests in recent years. Through simulations based on OPF using a sample network, this study illustrates and compares the savings of the total system production cost under three different scenarios: with no device installed, with SC installed and with CSC installed on the corresponding transmission corridor. The results are based on the accumulation of the production costs over a year while the four seasons are modeled using different generation and load patterns. In particular, the results have shown that, under some network conditions, there is more gain from CSC over SC, because of CSC´s ability to make use of the transfer capability in the neighbored area. In addition to the seasonal effects, studies and comparisons are also made for cases with multiple CSC and with CSC operating under constant power flow operation mode. In the multiple CSC case, the effects of installing multiple devices are investigated. In the other case, CSC is set to operate under constant power operation mode, which is in fact the most common way CSC is being used nowadays. The case results demonstrate that there are apparent benefits from using CSC