Motor 2 Stator Resistance; Motor 2 Voltage Offset; Motor 2 Transient Inductance - Emerson 2202 Advanced User's Manual

Parameter
Menu 21 Introduction
x.00
21.12

Motor 2 stator resistance

Bit SP
Coding
0.000 to 65.000 Ω
Range
Default 0.000
First motor
Pr 5.17
parameter
Update rate Background
This parameter contains the stator resistance of the machine for open loop vector mode operation.
If the drive cannot achieve the necessary current levels to measure the stator resistance during an auto-tune (e.g. there is no motor connected to the
drive) an rS trip will occur and the value in Pr 21.12 remains unchanged. If the necessary current levels can be achieved but the calculated resistance
exceeds the maximum allowable value for that particular drive size, an rS trip will occur and Pr 21.12 will contain the maximum allowable value.
21.13

Motor 2 voltage offset

Bit SP
Coding
Range 0.0 to 25.0 V
Default 0.0
First motor
Pr 5.23
parameter
Update rate Background
Due to various effects in the drive inverter a voltage offset must be produced before any current flows. To obtain good performance at low frequencies
where the machine terminal voltage is small this offset must be taken into account. The value shown in Pr 21.13 is this offset given in line to line rms volts.
It is not possible for the user to measure this voltage easily, and so the automatic measurement procedure should be used (see Pr 5.14 on page 79).
Motor 2 transient inductance (σL
21.14
Bit SP
Coding
Range 0.00 to 320.00 mH
Default 0.00
First motor
Pr 5.24
parameter
Update rate Background
With reference to the following diagram, the transient inductance is defined as
σL
= L + (L .L / (L + L
s 1 2 m 2
R jwL
1 1
jwL
Steady state per phase equivalent circuit
of an induction motor
Based on the parameters normally used for the motor equivalent circuit for transient analysis, i.e. L
is given by:
2
σL = L - (L / L )
s s m r
The transient inductance is used as an intermediate variable to calculate the power factor.
194
Parameter Keypad and
description format display
FI DE Txt VM DP ND
3
FI DE Txt VM DP ND
1
)
s
FI DE Txt VM DP ND
2
))
m
jwL
2
R /s
m 2
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Serial CT Modbus PLC Ladder
communications RTU programming
RA NC NV PT US RW BU
1 1 1
RA NC NV PT US RW BU
1 1 1
RA NC NV PT US RW BU
1 1 1
Advanced parameter
CTSoft Menu 0
PS
1
PS
1
PS
1
= L + L , L = L + L , the transient inductance
s 1 m r 2 m
Commander SK Advanced User Guide
descriptions
Issue Number: 9