The growing share of power-electronic-based loads on low-voltage distribution networks — electric vehicle (EV) chargers, variable frequency drives (VFDs), switched-mode power supplies (SMPS), LED lighting drivers, and data-centre infrastructure — is changing the reactive power profile that utilities must manage. Unlike conventional linear loads, these devices draw non-sinusoidal current, depress the effective power factor, and introduce harmonic distortion that static VAR compensators (SVC) and conventional capacitor banks cannot correct. The Static Synchronous Compensator (STATCOM), a voltage-source-converter-based Flexible AC Transmission System (FACTS) device, has emerged as a faster and more versatile alternative. This paper reviews how modern non-linear loads alter reactive power demand at the distribution level and comparatively surveys the principal multilevel converter/STATCOM topologies reported in the literature — two-level and multipulse configurations, neutral-point-clamped (NPC), flying capacitor (FC), cascaded H-bridge (CHB), modular multilevel converter (MMC), and hybrid arrangements — evaluating them against switch count, harmonic performance, control complexity, and suitability for distribution-level deployment. The review finds that while CHB and MMC topologies dominate high-power transmission-level STATCOM applications, reducedswitch-count and hybrid-clamped variants remain the more practical direction for low-voltage, distribution-connected compensators addressing modern residential and light-industrial nonlinear loads. Gaps in the existing literature specific to EV-charging-dominated low-voltage feeders are identified as a direction for future work.

Impact of Modern Non-Linear Loads on Reactive Power Demand and Power Quality A Comparative Review of STATCOM Topologies for Distribution Systems