STABILITY ASSESSMENT OF SYNCHRONOUS MOTORS IN THE PLANE OF TWO ANGLES
Relevance The main technological installations of the oil and gas industry require power supply of the first category and are fed from two independent sources. Possible short-term interruptions of power supply of such installations by their duration should not lead to a violation of the stability of electric motors and disruption of technological processes. The problem of stability at enterprises equipped with automatic standby switching devices with self-starting of synchronous motors after a short interruption of power supply is especially relevant. Therefore, the assessment of conditions for preserving the dynamic stability of synchronous motors after a short interruption of power supply is an urgent task. Aim of research Based on the method of areas, develop a method for assessing the dynamic stability of synchronous motors in the plane of two parameters. Methods The article uses dynamic stability areas in the plane of two angles to assess the dynamic stability of synchronous motors: the load angle of the synchronous motor in the pre-emergency mode δ0 and the inclusion angle δвкл between the mains voltage vectors and the residual voltage on the section that lost power, in the emergency mode. Results The dynamic stability area in the plane of two angles is plotted: the load angle δ0 and the turn-on angle δвкл. The boundary lines of dynamic stability area are plotted for the range of values of load angles, in which the static stability of the synchronous motor in the pre-emergency mode is preserved. On the example of synchronous motor of STD-2500 type, the definition of the dynamic stability area in the plane of parameters under study is shown. It is shown that the region of dynamic stability in the plane of two angles can be transformed into the dynamic stability area of other investigated parameters.