Static compensator (STATCOM)

Electrical loads generate as well as absorb reactive power. Since the load often varies considerably from one hour to the next, the reactive power balance in a grid varies as well. This can result in voltage variations, including voltage depression or even voltage collapse. 

Similar to  SVC  but with faster response,  STATCOM continuously provides reactive power in response to voltage variations, that supports the stability of the grid. STATCOM operates according to voltage source converter (VSC) principles, combining unique PWM (pulse width modulation) with millisecond switching. STATCOM functions with limited need for harmonic filters, contributing to a smaller footprint. If required, switched or fixed air core reactors and capacitors can be used with the VSC as additional reactive power elements to achieve any desired range. 

Installing a STATCOM at one or more suitable points in a grid increases the power transfer capability of the grid by improving voltage stability and continuously maintaining a smooth voltage profile under different network conditions. It is also capable of active filtering, which contributes to further enhancement of power quality. 

Hitachi Energy's offering for STATCOM includes SVC Light® STATCOM, SVC Light® Enhanced STATCOM, PCS 6000 STATCOM and STATCOM for distributed power.  PCS 6000 STATCOM is applicable for unit ratings up to 40 Mvar and SVC Light® STATCOM is applicable for ratings exceeding 40 Mvar. 
SVC Light® Enhanced combines capabilities of supercapacitors to further strengthen the grid. STATCOM for distributed power supports any requirement from 3-20 Mvar.