64
k
tTT
R
bm
C
tm
C
tL
R
bL
C
tmL
D
Parameter Estimation
State Estimation
measured
T
S_measured
simulated
T
S_simulated
Load Model
T
em
Figure 41 Block diagram of load model parameter estimation process
4.3.4 Standard Motor Model Parameters
The unknown parameters of the standard motor model are the stator resistance, r
s
, the rotor
resistance, r
r
, the stator leakage reactance, x
ls
, the rotor leakage reactance, x
lr
, and the
magnetizing reactance, x
m
.
For the standard motor model parameter estimation process, experimental data acquired
during a motor start is used. Data from a motor start is a good data set because the speed
varies from 0 to rated speed and the current varies from peak starting current to rated current.
This will expose the parameter estimation process to a wide range of motor operation. The
speed and stator currents are used as the measurement data. It is not necessary to use the
shaft torque measurement data for the motor parameter estimation process since this data was
previously used for the dynamic load model parameter estimation process.
Figure 42 shows a block diagram of the motor model parameter estimation process. The
step-by-step process is as follows:
1)
Obtain supply voltage data from a motor start and determine the supply voltage
frequency, f
rated.
2)
Obtain measured speed data,
r
, and stator current data, i
as
, i
bs
, i
cs
, from a motor start.
3) Filter all measured data using a binomial filtering algorithm [46].