Static synchronous compensator STATCOM

with harmonic filter

Combining STATCOM and classic SVC technologies With high power semiconductors becoming commercially available, STATCOM (Static Synchronous Compensator) technology began being deployed in the late 1990s. Hitachi Energy STATCOM, under the brand name of SVC Light®, is based on chain-link modular multilevel (MMC) voltage source converters (VSC), particularly adapted for power system applications. It is capable of providing high reactive power in grids more or less unimpeded by suppressed voltages, and with a high dynamic response. Further development has combined VSC technology with that of thyristor-based SVC (Static Var Compensator), combining the best of both technologies and offering joint benefits by incorporating Thyristor Switched Capacitors (TSC) and Thyristor-Switched Reactors (TSR) to create a Hybrid STATCOM solution. In general, STATCOM comes into the picture where available space in substations is scarce, the reactive power output needs to be controllable more or less independent of the AC system voltage, or a speed of response is desired one order of magnitude greater than what is possible with thyristors. Also, VSC based solutions are less sensitive and dependent on network conditions. Harmonic filters in classic SVCs are a weak point, as their performance depends entirely on the harmonic impedance of the network. STATCOM in itself provides a symmetrical operating range. For asymmetrical operation and in order to optimize performance, Hybrid STATCOM may be the best solution, in particular for very large Mvar operation ranges.