A Method to Determine Load Conditions for Salient Pole Synchronous Machine Quadrature Axis Parameters Determination

In this paper a new method to determine load conditions for the load rejection tests for salient pole synchronous machines q-axis parameters determination is introduced. The method is based on the solution of a non linear system that is deduced from the equations of active and reactive power as functions of the different angles defined in the salient pole synchronous machine phasor diagram. With the proposed method, a time consuming trial and error procedure and the installation of a power angle measuring devices are not necessary, making the load rejection test easier and faster to perform, what is desirable to test large power plant units. To test the results obtained with the method described in this paper, some rejections of loads satisfying the calculated conditions are simulated and the results show that the armature currents are on the q-axis, allowing the determination of the salient pole synchronous machine q-axis parameters. The method presented in this paper is an extension of the method already developed and published by the author to solve a similar problem for round rotor synchronous machines.