Standards Development

Scope

This document provides guidance on automatic voltage control for power systems with integration of inverter-based resources (IBRs). It covers aspects such as implementation frameworks, requirements for associated terminals, agent control stations, and mast er stations, as well as performance evaluation criteria. This document is applicable to automatic voltage control of inverter - based resource plants connected to the power grid at a voltage level of 10kV and above, and excludes inverter-based resources connected at a voltage level below 10 kV and those owned by end-users.

To better harmonize the technical aspects across stakeholder, the project team will maintain close working contacts with TC8 SC8A, TC88, TC120, TC82.

Purpose

Automatic voltage control technology—now widely adopted globally—serves as a cornerstone of modern power system operation. As power systems worldwide evolve toward greater complexity, higher renewable energy penetration, and more decentralized structures, voltage control systems have become increasingly critical to maintaining reliable system operation. This importance is underscored by incidents like the unreasonable switching of reactive power devices, which exacerbated the spread of the major blackout in Spain and Portugal.

Notably, there remains a distinct gap in IEC standards regarding the functional requirements and architectural design of voltage control technologies. Existing standards specify the capability of power plant-side resources for voltage and reactive power re gulation. However, the implementation of coordinated voltage control systems represents a critical next step —one that enables fuller utilization of these inherent capabilities to ensure the safe and stable operation of system voltage.

China has also built a nationwide automatic voltage control infrastructure, which covers ultra -high- voltage (UHV) transmission networks, large-scale thermal and hydro generation bases, and rapidly expanding renewable energy zones. Particularly within Jiang su Province, the voltage control system features in flexible network partitioning capability, which enables dynamic adaptation to the grid’s ever-changing conditions. Unlike rigid, static zoning models, this flexible approach allows the Automatic voltage control system to redefine control boundaries in real time based on load fluctuations, renewable generation variability, and network topology changes.

We stand ready to collaborate with global experts to advance this critical work, ensuring that automatic voltage control technologies continue to underpin the stability and resilience of power systems worldwide.

Rationale for Advancing Standardization Within SC8C Committee

SC8C, as a key committee focused on power system control and operation standards, has long been dedicated to addressing critical issues related to the reliability, security, and efficiency of power systems. Its scope explicitly encompasses the development of standards for power system control strategies, coordination mechanisms, and operational protocols that ensure stable and secure grid operation—all of which are central to the domain of automatic voltage control. The proposed project will focus on specifying the functions and technologies involved in utilizing and coordinating the voltage control capabilities on the plant -side from the perspective of improving system stability. And it will not impose additional requirements on the plant -side regulation characteristics beyond the standards issued by TC8 SC8A, TC88, TC120, and TC82, as well as the standards corresponding to the ongoing work of these committees. The main content is consistent with the scope of work of TC8 SC8C.