What are the similarities and differences between a Static Var Compensator (SVC) and a Static Var Generator (SVG)?

Static Var Compensator (SVC) generates reactive power and filters harmonics relying on the inherent characteristics of its capacitors and reactors.
 
Static Var Generator (SVG) generates reactive power and suppresses harmonics through frequent switching of its internal electronic switches, which produce reactive current and counter‑currents offsetting harmonic currents.
 
Static Var Compensator, abbreviated as SVC, differs from traditional reactive power compensation devices that switch capacitors by circuit breakers or contactors. SVC uses electronic switches such as thyristors and has no mechanical moving parts, therefore it is defined as a static reactive power compensation device.
 
A typical SVC consists of the following parts:
 
A reactive power compensation and filtering branch made up of fixed capacitors and fixed reactors. By properly selecting the capacity of reactors and capacitors, this branch can filter power grid harmonics, compensate capacitive reactive power and keep the power grid in a capacitive state.
Fixed reactors
Thyristor‑based electronic switches 
Thyristors are used to adjust the conduction angle of reactors, change the output of inductive reactive power to counteract the capacitive reactive power from the compensation‑filtering branch, and maintain a high inductive power factor.