KV变电站设计.doc

摘 要 VQC控制系统是提高电压合格率、降低网损、提高系统稳定性的有效手段和重要措施。系统无功分布的合理与否，电压质量的好坏，直接影响着电力系统的安全稳定与经济运行。无功不足将导致系统电压下降，用电设备不能充分利用，更为严重的是如果系统的无功不足，将使系统的整体电压水平低下，系统一旦发生较大的扰动，就可能使电压低于临界电压，产生电压崩溃，从而导致系统因失去同步而瓦解的灾难性事故；无功过剩亦会导致电压过高，危害系统和设备的安全，恶化系统电压状况，浪费不必要的投资；无功的不合理流，会使线路的压降增大、线路的损耗增加、供电的安全性和经济性都会下降。因此，合理的运用电压无功的调节手段，提高优化控制水平，不仅能改善电压质量和提高电压合格率，而且能够有效的降低网损，提高电力系统运行的安全性和经济性。 变电站VQC（电压无功综合控制)系统主要是以微处理器为核心组成的控制系统和软件模块组合的自动装置。它能根据变电站各种运行方式和自适应跟踪系统，通过一定的控制策略，对有载调压变压器的分接头切换及并联电容器组、电抗器等无功设备的选择投切，来控制电源侧无功功率和负荷侧母线电压，以保证供电电压和功率因数始终在合格的范围内变动，从而提高电能质量和系统的安全、经济运行水平。 关键词：电压无功综合控制，控制策略 ABSTRACT The VQC control system is enhances the voltage qualified rate, reduces the net to damage, to enhance the system stable effective method and the important measure.System idle work distribution reasonable or not, the voltage quality quality, is affecting the electrical power system security directly stable and the economical movement.The idle work insufficient will cause the system voltage to drop, the current collector will not be able to use fully, more serious will be if the system idle work will be insufficient, will cause the system the overall voltage level to be low, once the system will have the big perturbation, possibly will cause the voltage to be lower than the threshold voltage, will produce the voltage to collapse, thus will cause the system the disastrous accident which will disintegrate because of fall out of step; The idle work surplus also can cause the overtension, the harm system and the equipment security, the worsened system voltage condition, wastes the nonessential investment; The idle work unreasonable class, can cause the line the pressure drop to increase, the line loss increases, the power supply security and the efficiency can drop.Therefore, the reasonable working voltage idle work adjustment method, raises the optimization control level, not only can improve the voltage quality and enhance the voltage qualified rate, moreover can effective reduce the net to damage, enhances the electrica