Electrical loads both generate and absorb reactive power. Since the transmitted load often varies considerably from one hour to the next, the reactive power balance in a grid varies as well. This can result in unacceptable variations in voltage amplitude, including voltage depression or even voltage collapse.
Like an SVC, the STATCOM instantly and continuously provides variable reactive power in response to voltage transients, supporting the stability of grid voltage. The STATCOM operates according to voltage source principles, combining unique PWM (pulse width modulation) switching in IGBTs (insulated gate bipolar transistors). The unit`s effective rating and response speed is unequalled, and can be dedicated to active harmonic filtering and voltage flicker mitigation. Its components mean the STATCOM`s footprint can be extremely small, and Hitachi Energy has branded this downsized, high-performance STATCOM concept SVC Light.
Installing a STATCOM at one or more suitable points in a grid will increase power transfer capability by enhancing voltage stability and maintaining a smooth voltage profile under different network conditions. The STATCOM also enables improvements in power quality.