IEEE 421.1-2007 pdf free.IEEE Standard Definitions for Excitation Systems for Synchronous Machines.
IEEE 421.1 defines elements and commonly used components in excitation control systems and contains definitions for excitation systems as applied to synchronous machines. These definitions should be useful in the following areas:
— Writing excitation systems specifications
— Evaluating excitation system performance
— Specifying methods for excitation system tests
— Preparing related excitation system standards
— Serving as an educational means for those becoming acquainted with excitation systems
— Modeling excitation systems
2. Normative references
The following referenced documents are indispensable for the application of this standard. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments or corrigenda) applies.
For the purposes of this standard, the following terms and definitions apply. The Authoritative Dictionary ofIEEE Standards Terms LRI ij should be referenced for terms not defined in this clause.
3.1 ac field breaker: A circuit breaker used to disconnect the excitation system from the power potential
transformer (PPT) or ac supply. See also: de-excitation.
3.2 ac regulator: See: voltage regulator.
3.3 adjuster: A device or function by which the set point is determined.
3.4 air-gap field voltage: The synchronous machine field voltage required to produce rated voltage on the air-gap line of the synchronous machine with its field winding at I) 75 °C for field windings designed to operate at rating with a temperature rise of 60 °C or less: or 2) 100 °C for field windings designed to operate at rating with a temperature rise greater than 60 °C.
NOTE—This defines one per unit excitation system voltage for use in computer representation of excitation systems.4 3.5 air-gap line: The extended straight line part of the no-load saturation curve of the synchronous machine.
3.6 alternator-rectifier exciter: An exciter whose energy is derived from an alternator and converted to direct current by rectifiers. The exciter includes an alternator and power rectifiers that may be either noncontrolled or controlled, including gate circuitry. It is exclusive of input control elements. The alternator may be driven by any type of prime mover, most commonly the shaft of the synchronous machine. The rectifiers may be stationary or rotating with the alternator shaft.
3.7 automatic control: In excitation control system usage, automatic control refers to maintaining synchronous machine terminal voltage at a predetermined level without operator action, over the operating range of the synchronous machine.
NOTE —Voltage regulation may be modified by the action of load current compensators, power factor or var controllers. poWer system stabilizers, or may be constrained by the action of various limiters included in the excitation system.IEEE 421.1 pdf download.