With the increasing penetration of renewable energy, power systems are facing growing challenges in voltage and frequency stability. Synchronous condensers (SCs) have attracted renewed attention due to their capabilities in providing dynamic reactive power support, improving voltage regulation characteristics, and providing rotational inertia. This paper reviews the development history and research status of six main types of SCs based primarily on their machine structures and operating principles, including conventional synchronous condensers (CSCs), superconducting synchronous condensers (SSCs), dual-excited synchronous condensers (DESCs), high-inertia synchronous condensers (HISCs), energy storage synchronous condensers (ESSCs), and phase modulation conversion of power units. A comparative analysis is further conducted in terms of cost, performance, technical advantages, and typical application scenarios, thereby clarifying the technical rationale for selecting suitable SC technologies for different power system requirements. Finally, several promising avenues for future research on SC technologies are proposed.
Wang et al. (Thu,) studied this question.