CONTROL SYSTEM FOR STABILIZATION OF LINE

• Main Authors: KOWADA YASUYUKI, OSHIDA HIDEJI, MIZUTANI SHIGEO
• Format: Patent
• Language: English
• Published: 22.04.1994
• Edition: 5
• Subjects: CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTINGELECTRIC POWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION; SYSTEMS FOR STORING ELECTRIC ENERGY

PURPOSE:To prevent the phenomenon of power swing due to the divergence of oscillation at the minimum required control variable for a power supply before it happens by detecting the preestimate of power swing from the shaking of the locus of an effective and an ineffective power before the phenomenon of divergence of oscillation generated from a power line reaches the power swing between generators. CONSTITUTION:It is decided that a central unit 1A is brought into the state of power swing by the next shaking when the declination 0 of a chord vector stretched in the shape of an arc having a certain length on a locus of PQ exceeds a detection level for the preestimate of power swing. Next, the central unit 1A determines a control variable for a power supply required for preventing the power swing from the corresponding factor to the maximum swing width in the direction of a Q-axis in the PQ locus of the shaking which exceeds the detection level for the preestimate of power swing, before it happens, to select a generator corresponding to the variable according to an appropriate order of priority from the generators 61A1 to 61AM, 61B1 to 61BN. And then the central unit A determines that the PQ locus enters into the inner part of a second quadrant and then into the region immediately after the change of the tidal current P of an effective power is inverted from the decrease to the increase, and immediately outputs a trip signal to the breaker 41 of the selected generator 61.