Double Excitation Resolver Model

Double excitation resover

Some resolvers have two rotor windings at 90º degrees to each other, as represented in the figure below.

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Double excitation resolver

For the double excitation resolver, the equations can be expressed as follows:

When the gains are set to its default values (, , , , , , and ), the sensor rotation is clockwise, and the excitations are in quadrature ( and , where is the excitation frequency), the outputs are given by the following expressions:

which means the excitaition signals are shifted by the rotor position angle.

Excitation source

For the double excitation resolver, the excitation source can be selected between an internally generated AC signal or an external one, as described for the single excitation. When the AC option is selected, the signals have unit amplitude, constant frequency, and are in quadrature, with the second excitation leading by 90 degrees.