6. A System for Measuring Generator Load Angle

This chapter, the developed system for measuring generator load angle is presented. To determine the load angle, information about the current values of the stator voltage phasor angle and the rotor position angle, i.e. the angle of the q axis along which the phasor of the voltage \(E_{\text{q}}^{'}\)(t) lies, is necessary. The use of four types of sensors for measuring the rotor angle is described. The sensors tested and later used in measurements are: optoelectronic position sensors—encoders, general purpose optical sensors, magnetic field sensors and synchronous tachogenerators. The stator voltage phasor angle can be determined indirectly by using measurements of the stator generator voltage or by measuring the position of the magnetic field axis in the air gap. Both methods are presented. Due to the fact that determination of the axial components of the stator voltage phasor is necessary during the parameter estimation of the synchronous generator mathematical model, the method consisting in determination of axial components of this voltage was used to determine the stator voltage phasor angle in laboratory and industrial investigations.