FIELD: electrical engineering; automatic emergency management facilities for power-systems.
SUBSTANCE: proposed method includes calculation of impedance vector as voltage-to-current vector ratio in point under check. Impedance vector projection onto axis turned in complex plane of impedances relative to imaginary axis through angle supplementing rated angle of equivalent power transmission impedance to 90 deg. is calculated. Resistance up to electrical center of oscillations is found by projection. Disposition of center of oscillations on line section under check is recorded when projection value occurs within specified range. Vector of voltage being measured onto axis turned in complex plane relative to power transmission current vector through same additional angle is calculated. Power transmission angle is calculated by voltage projection using simple trigonometric function. Asynchronous mode onset is detected by coincidence between signs of power transmission angle and those of its first and second time derivatives. Asynchronous mode hazard is recognized by excess of first derivative above admissible value calculated with aid of "angle-slip" boundary phase functions and parameters of original modes.
EFFECT: enhanced selectivity and stability of asynchronous mode detection and reduced number of automatic management inadequate responses.
2 cl, 7 dwg
