I am Working on an Induction Machine. Could someone give me any reason for the transformation of the input voltage Vao, Vbo, Vco to Van, Vbn, Vcn, using isolated neutral network O-to-n? The input is multiplied by matrix [2/3 -1/3 -1/3 ; -1/3 2/3 -1/3; -1/3 -1/3 2/3].
According to Fortecue's Theorem a set of Three Unbalanced Phasors (need not necessarily be only Voltage or Current Phasors) can be represented using Three sets of Balanced Phasors called Positive, Negative and Zero sequence Components of the Phasors using Symmetrical Components Matrix. If the Original Phasors are Balanced we have only Positive Sequence Components Present.
In the case of Power Systems,any type of Faults can be Analyzed using the Symmetrical Components of Voltages/Currents ,and get the Positive,Negative and Zero Sequence Components of Fault Currents. But to get back the Original Phasor Components of Fault currents we use inverse of Symmetrical component Matrix..
If the Fault involves Ground,then only we will have Zero sequence components Present. in which case and we go for the transformation of the input voltage Vao, Vbo, Vco to Van, Vbn, Vcn, using isolated neutral network O-to-n.
In Sim power Systems the d q 0 Block is used.
The abc_to_dq0 Transformation block computes the direct axis, quadratic axis, and zero sequence quantities in a two-axis rotating reference frame for a three-phase sinusoidal signal. The following transformation is used:
This transformation is commonly used in three-phase electric machine models, where it is known as a Park transformation It allows you to eliminate time-varying inductances by referring the stator and rotor quantities to a fixed or rotating reference frame. In the case of a synchronous machine, the stator quantities are referred to the rotor. Id and Iq represent the two DC currents flowing in the two equivalent rotor windings (d winding directly on the same axis as the field winding, and q winding on the quadratic axis), producing the same flux as the stator Ia, Ib, and Ic currents.
You can use the Math Function block and the Trigonometric Function block to obtain the modulus and angle of V1:
P.S.
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