GB/T 7409.4-2023Excitation systems for synchronous machines - Part 4: Technical requirements of excitation systems for medium and small synchronous machines (English PDF)

Foreword

This document was issued on 7 September 2023 by the State Administration for Market Regulation; Standardization Administration of the PRC and takes effect on 1 April 2024.

It is a GB/T standard: recommended rather than compulsory, but it is the text a Chinese reviewer applies when assessing a submission.

1 Scope

GB/T 7409.4-2023 is Part 4 of the Chinese series on excitation systems for synchronous machines, and sets the technical requirements for medium and small machines. The excitation system is what controls the field current, and through it the terminal voltage and the reactive power a generator delivers; it is also what has to force the field up in the first cycles of a fault to keep the machine in step, and then bring it back without hunting. On smaller machines - distributed generation, industrial sets, synchronous motors and condensers - the same duties must be met with far simpler and cheaper equipment. The standard sets the general requirements and conditions of use, the performance requirements for the excitation systems of synchronous generators and separately of synchronous machines, the test rules, the equipment completeness, the marking, packaging, transport and storage, and the production and quality assurance requirements. It took effect on 1 April 2024.

This document specifies the general requirements and usage conditions for the excitation

systems for medium and small synchronous machines, the performance requirements for the

excitation systems for synchronous generators, the performance requirements for the excitation

systems for synchronous machines, the test rules, equipment completeness, marking, packaging,

transportation and storage, as well as mass production and quality assurance, etc.

This document is applicable to the design and manufacturing of the excitation systems for 50

Hz and 60 Hz synchronous machines in the following scopes:

---hydraulic generators below 10,000 kW;

---turbine generators below 6,000 kW;

---internal combustion generators of 3,200 kW and below;

---synchronous machines below 10,000 kW.

2 Normative References

The contents of the following documents constitute indispensable clauses of this document

through the normative references in the text. In terms of references with a specified date, only

versions with a specified date are applicable to this document. In terms of references without a

specified date, the latest version (including all the modifications) is applicable to this document.

GB/T 191-2008 Packaging - Pictorial Marking for Handling of Goods

GB/T 755 Rotating Electrical Machines - Rating and Performance

GB/T 1094 (all parts) Power Transformers

GB/T 3797-2016 Electrical Control Assemblies

GB/T 7409.1-2008 Excitation Systems for Synchronous Electrical Machines - Definitions

GB/T 7409.2-2020 Excitation Systems for Synchronous Electrical Machines - Part 2: Models

for Power System Studies

The time required from the start of disturbance, until the difference between the generator

terminal voltage and the steady-state value does not exceed 3% of the rated value (or otherwise

specified) and remains within this area.

NOTE: the unit is second (s).