IEC TS 62933-2-3:2025

Overview

IEC TS 62933-2-3:2025 - "Electric Energy Storage (EES) Systems - Part 2-3: Unit parameters and testing methods - Performance assessment test during site operation" specifies unit parameters and standardized testing methods to validate and assess the operational performance of EES systems after commissioning. The Technical Specification focuses on on-site performance assessment (post-commissioning) including data requirements, sampling intervals, test prioritization and practical test procedures for grid-connected and islanded operation.

Key topics and requirements

The document defines general requirements and a comprehensive set of operational performance testing items and methods, including:

• General requirements: purpose, stakeholders, data requirements, assessment intervals and sampling principles, and prioritization of tests.
• Basic unit parameters: actual energy storage capacity, input and output power rating, roundtrip efficiency, and auxiliary power consumption.
• Energy-related metrics: available hours and equivalent operation factor.
• Efficiency metrics: comprehensive efficiency, energy loss rate, and duty-cycle roundtrip efficiency.
• Reliability metrics: planned outage factor, unplanned outage factor, and availability factor.
• Grid-connected tests: impact of grid conditions, active and reactive power control tests, primary and secondary frequency regulation tests, and grid-connected power quality tests.
• Application-specific tests: tests tailored for frequency regulation, fluctuation reduction, reactive power/voltage control, power quality management, peak shaving/peak shifting, renewable firming, islanded grid operation and backup power.
• Test methodology: stepwise methods for each item, example test curves, response-time assessments, and performance indicator tables for stakeholders.

Practical applications

IEC TS 62933-2-3 is intended to provide repeatable, comparable procedures for assessing real-world EES performance during site operation. Typical uses include:

• Verifying that a commissioned EES system meets contractual performance guarantees (capacity, efficiency, availability).
• Benchmarking asset performance for operators, owners and asset managers.
• Supporting grid-interconnection testing and proving frequency/voltage control capabilities for grid operators and system integrators.
• Informing maintenance planning through reliability metrics (planned/unplanned outages).
• Evaluating system performance in specific modes (peak shaving, renewable firming, islanding, backup).

Who should use this standard

• EES system manufacturers and integrators
• Owners, operators and asset managers of battery and other storage plants
• Test laboratories and commissioning teams
• Grid operators, regulators and certification bodies
• Project developers and technical consultants

Related standards

• Part of the IEC 62933 series on Electrical Energy Storage (EES) systems.
• Intended to be applied alongside applicable grid codes and power-quality standards and other IEC publications relevant to EES commissioning and operation.

Keywords: EES systems, performance assessment test, site operation, unit parameters, testing methods, roundtrip efficiency, grid-connected testing, battery energy storage, operational performance testing.