Question

How does a STATCOM compensate for grid voltage instability compared to a passive capacitor bank during a sudden drop in renewable power injection?

Accepted Answer

A passive capacitor bank provides reactive power proportional to the square of the grid voltage. Reactive power is the energy that oscillates between the source and the load to maintain the magnetic or electric fields required by grid equipment. When a sudden drop in renewable power injection causes a decrease in grid voltage, a passive capacitor bank automatically produces less reactive power exactly when more is needed to stabilize the voltage. This makes it ineffective during severe voltage drops. A STATCOM, or Static Synchronous Compensator, is a power electronics device that acts as a controlled voltage source by using insulated-gate bipolar transistors to convert DC power from a capacitor into AC power. Unlike a passive bank, a STATCOM can independently control the magnitude and phase of its output current regardless of the grid voltage. When the grid voltage drops, the STATCOM detects the deficiency and instantly injects reactive current into the grid to support the voltage. Because it uses fast-switching semiconductors, a STATCOM can transition from supplying to absorbing reactive power in milliseconds, providing dynamic and continuous voltage regulation that does not decline as the grid voltage falls.

Home → All Courses → Engineering and Technology Courses → Renewable Energy Systems Engineering → Flashcard

How does a STATCOM compensate for grid voltage instability compared to a passive capacitor bank during a sudden drop in renewable power injection?