| 摘要 |
<p>A method for operation of a power system's anti-collapse automatics, in which a two-parameter centralized system is employed. One of the parameters is the power flow in the protected network cross-section as the criterion of the severity of a power system's operating condition, which is determined in real time under normal operating condition. The second parameter is the signal about emergency disconnection of a power system's element, which is sent through a logic signal channel. The determination of overload in a network cross-section due to possible emergency disconnections and of the place for sectioning the power system is performed by the mathematical model employed in protection. Taking into account the rare occurrence of collapses and that the self-liquidation principle allows the emergency to be eliminated within 1-1.5 min, variable optimal sectioning places are replaced with a fixed place using a non-branched logic control channel. After sectioning, in the deficient part of a PS the frequency restores up to the nominal value using the slow under frequency load shedding automatics [slow AUFLS]. In the PS part with power surplus the frequency rise retards the automatic PS re-integration by synchronization using the synchronism-check devices available on the lines for complete emergency liquidation. In this case, to reduce frequency to the nominal value thus ensuring successful synchronization, for some of the turbines forced changes in the settings of speed governors should be applied with the purpose to simplify the protection system and to facilitate its implementation.</p> |
