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Synchronous Machine Measurement

Per-unit measurement from synchronous machine

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  • Synchronous Machine Measurement block


The Synchronous Machine Measurement block outputs a per-unit measurement associated with a connected Synchronous Machine Round Rotor or Synchronous Machine Salient Pole block. The input of the Synchronous Machine Measurement block connects to the pu output port of the synchronous machine block.

You set the Output parameter to a per-unit measurement associated with the synchronous machine. Based on the value you select, the Synchronous Machine Measurement block:

  • Directly outputs the value of an element in the input signal vector

  • Calculates the per-unit measurement by using values of elements in the input signal vector in mathematical expressions

The Synchronous Machine Measurement block outputs a per-unit measurement from the synchronous machine according to the output value expressions in the table. For example, when you set Output to Stator d-axis voltage, the block directly outputs the value of the pu_ed element in the input signal vector. However, when you set Output to Reactive power, the block calculates the value from the pu_ed, pu_eq, pu_id, and pu_iq elements.

Output Parameter SettingOutput Value Expression

Field voltage (field circuit base, Efd)


Field current (field circuit base, Ifd)


Electrical torque


Rotor velocity


Stator d-axis voltage


Stator q-axis voltage


Stator zero-sequence voltage


Stator d-axis current


Stator q-axis current


Stator zero-sequence current


Apparent power


Real power

pu_Pt = (pu_ed*pu_id) + (pu_eq*pu_iq) + 2(pu_e0*pu_i0)

Reactive power

pu_Qt = (pu_eq*pu_id) – (pu_ed*pu_iq)

Terminal voltage


Terminal current


Power factor angle (rad)

power_factor_angle = atan2(pu_Qt, pu_Pt)

Power factor


Load angle (rad)

load_angle(rad) = atan2(pu_ed, pu_eq)

Rotor electrical angle

y = pi+2*atan(tan((u-pi)/2))



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Physical signal vector port associated with per-unit measurements from a connected synchronous machine. The vector elements are:

  • pu_fd_Efd

  • pu_fd_Ifd

  • pu_torque

  • pu_velocity

  • pu_ed

  • pu_eq

  • pu_e0

  • pu_id

  • pu_iq

  • pu_i0


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Physical signal output port associated with the per-unit measurement.


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Per-unit measurement from synchronous machine. The default value is Field voltage (field circuit base, Efd).

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Version History

Introduced in R2013b