IEEE 115A-1987

IEEE 115A-1987 is a technical standard for obtaining synchronous machine parameters by standstill frequency response testing. It addresses a specialized measurement method used to characterize machine behavior without rotating the machine, which can support better analysis of power-system equipment and related components. In power, energy, and industrial applications, this type of document helps engineers compare results more consistently and make informed decisions about testing, design review, and performance assessment.

Overview of IEEE 115A-1987

This standard focuses on procedures for deriving synchronous machine parameters from standstill frequency response data. Its scope is tied to electrical machines used in power and industrial systems, where parameter identification can influence modeling and evaluation. IEEE 115A-1987 is especially relevant when engineers need a defined test approach that supports repeatable measurements and more reliable interpretation of machine characteristics. As a superseded standard, it remains useful for understanding established testing practice and historical documentation.

Typical use cases

IEEE 115A-1987 is commonly used when evaluating synchronous machines in commissioning, diagnostic testing, or engineering studies that require parameter extraction from standstill conditions. It may be applied to generators or similar rotating electrical equipment in utilities, large industrial facilities, and test laboratories. The procedure is also useful when preparing technical reports, comparing machine data across test programs, or supporting modeling work where consistent frequency response measurements are needed.

Why it matters

Standards such as IEEE 115A-1987 matter because they help reduce uncertainty in how test results are obtained and interpreted. A defined procedure supports consistency across teams, improves comparability between machines, and can lower the risk of misjudging synchronous machine performance. For procurement, maintenance, and engineering review, using a recognized test method can strengthen documentation and support more defensible decisions about equipment condition and suitability.

• Standstill frequency response testing
• Synchronous machine parameter identification
• Electrical machine testing procedures
• Power and industrial applications
• Historical IEEE technical guidance