GB/T 7409.1-2008Excitation systems for synchronous electrical machines -- Definitions (English PDF)

2.1 Excitation control system

Include the feedback control systems of synchronous machine and its excitation

system.

2.2 Excitation system

The equipment providing the field current of a synchronous machine, including all

regulating and control elements, as well as field discharge or suppression equipment

and protective devices.

2.3 Exciter

The source of the electrical power providing the field current of the synchronous

machine.

Note. Examples of the source are.

- A rotating machine, either DC or AC with associated rectifiers.

- One or several transformers with associated rectifiers […]

2.4 Excitation control

The control modifying the excitation power, responding to signal characteristics of the

stated of the system encompassing the synchronous machine, its exciter and the

network to which it is connected.

Note. Synchronous machine terminal voltage is predominantly the controlled quantity.

2.5 Field winding terminal

The place of input to the field winding of the machine.

Note 1.If there are brushes and slip-rings, these are considered to be part of the field winding.

2.25 Voltage response time of excitation system

The time required for suddenly changing the measured voltage value when the generator with

rated load operates at rated speed to make the excitation system output terminal voltage reach

95% of the difference in ceiling voltage and rated field voltage.

2.26 High initial response excitation system

The AC exciter excitation system with voltage response time less than or equal to 0.1s.

2.27 Excitation system forced cut-off

The tripping of synchronous machine caused by faults of excitation system.

2.28 Excitation system forced off ratio for a year F.O.R

The ratio by percentage between the excitation system forced cut-off hours and the sum of

handling hours and forced off hours within one year.

2.29 Excitation system abnormal forcing

The abnormal output increase of excitation system caused by the out-of-control of excitation

system.

2.30 Excitation system models

The mathematical formulation of excitation system established in power system stability

studies in order to simulate the behaviors of excitation system.

3.1 Rotating exciter

A rotating machine which takes mechanical power from a shaft. This shaft may be driven by

the synchronous machine or by another machine.

3.1.1 DC exciter

A rotating exciter employing a commutator and brushes to deliver direct current.

3.1.2 AC exciter

A rotating exciter employing rectifiers to deliver direct current. The rectifiers may be

controlled or uncontrolled.

3.1.2.1 AC exciter with stationary rectifiers

An AC exciter with stationary rectifiers whose output is connected to the brushes of the […]