IEC 60034-2-2 pdf download – Rotating electrical machines – Part 2-2: Specific methods for determining separate losses of large machines from tests – Supplement to IEC 60034-2-1

IEC 60034-2-2 pdf download – Rotating electrical machines – Part 2-2: Specific methods for determining separate losses of large machines from tests – Supplement to IEC 60034-2-1
1 scope
This part of IEC 60034 applies to large rotating electrical machines and establishes additionalmethods of determining separate losses and to define an efficiency supplementingIEC 60034-2-1. These methods apply when full-load testing is not practical and result in agreater uncertainty.
NOTEln situ testing according to the calorimetric method for full-load conditions is recognized.The specific methods described are:
-Calibrated-machine method.-Retardation method.
-Calorimetric method.Normative references
The following referenced documents are indispensable for the application of this document.For dated references,only the edition cited applies. For undated references, the latest editionof the referenced document (including any amendments) applies.
IEC 60034-1，Rotating electrical machines – Part 1: Rating and performance
IEC 60034-2-1，Rotating electrical machines – Part 2-1: Standard methods for determininglosses and efficiency from tests (excluding machines for traction vehicles)
Terms and definitions
For the purposes of this document,the terms and definitions given in lEC 60034-1 andlEC 60034-2-1 apply, as well as the following.
3.1
calibrated machine
machine whose mechanical power input/output is determined，with low uncertainty,usingmeasured electrical output/input values according to a defined test procedure
3.2
calibrated-machine method
method in which the mechanical input/output to/from an electrical machine under test isdetermined from the measurement of the electrical input/output of a calibrated machinemechanically coupled to the test machine
3.3
retardation method
method in which the separate losses in a machine under test are deduced from themeasurements of the deceleration rate of its rotating components when only these losses arepresent
3.4
calorimetric method
method in which the losses in a machine are deduced from the measurements of the heat generated by them
3.5
thermal equilibrium
the state reached when the temperature rises of the several parts of the machine do not vary by more than a gradient of 2 K per hour
[IEV 41 1 -51 -08]
4 Symbols
In addition to the symbols in IEC 60034-2-1 , the following apply.
4.1 Quantities
A is an area, m 2 ,
C is the retardation constant, kg m 2 min 2 ,
c p is the specific heat capacity of the cooling medium, J/(kg K),
h is the coefficient of heat transfer, W/(m 2 K),
J is the moment of inertia, kg m 2 ,
n is the speed, min –1 ,
P 1E is the excitation power supplied by a separate source, W,
P k is the constant loss, W,
P el is the electrical power, excluding excitation, W,
P e is the excitation power, W,
P Fe is the iron loss, W,
P fw is the friction and windage loss, W,
P sc is the short-circuit loss, W,
P mech is the mechanical power, W,
P T is the total loss, W,
Q is the volume rate of flow of the cooling medium, m 3 /s,
t is the time, s,
v is the exit velocity of cooling medium, m/s,
⊗ p is the difference between the static pressure in the intake nozzle and ambient pressure, N/m 2 ,
⊗ θ is the temperature rise of the cooling medium, or the temperature difference between the machine reference surface and the external ambient temperature, K,
δ is the per unit deviation of rotational speed from rated speed,
ρ is the density of the cooling medium, kg/m 3 ,
θ is the temperature, °C.
4.2 Subscripts
irs for inside reference surface,
ers for outside reference surface,
E for exciter,
c for the cooling circuit,
N for rated values,
rs for the reference surface,
t for a test procedure,
1 for input or initial condition,
2 for output condition.
5 Basic requirements
5.1 Direct and indirect efficiency determination
Tests can be grouped in the following categories.
5.1 .1 Direct
Input-output measurements on a single machine are considered to be direct. This involves the measurement of electrical or mechanical power into, and mechanical or electrical power out of a machine.