POLITECHNIKA WARSZAWSKA

5. Speed estimation of induction motor
u s
Induction Motor
v
.
+ x
B
I/s
x
C
+ +
+
i s
+
w
B
A(x)
^
+ x ^.
x^ i s -
+
C
I/s
+ +
A(x)
^
K
Fig. 5.5. Block diagram of EKF
In fact the EKF is a variant of the Kalman Filter, but the extended KF can be used for
a nonlinear systems. In the speed adaptive flux observers, the speed is considered as a
state variable. The design procedure is complicated and includes the following steps
for the discrete EKF algorithm
• Selection of discretized IM model,
• Determination of the noise and state covariance matrices,
• Implementation of the EKF algorithm
• Tuning
The most important features of the ELO and EKF can be summarized as below
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