中文摘要：

随着电网规模的发展、电力负荷水平的持续攀升,短路电流不断增大,严重影响电力变压器的安全运行。为此,提出了一种新型的变阻抗节能变压器技术,该技术将高阻抗变压器和限流电抗器这2种常用的限制电力变压器短路电流方法的优点结合起来。首先介绍了变阻抗变压器的工作原理,然后对限流电抗器的设计、快速开关开断技术、变压器短路电流的限流效果、暂态过电压分析和变阻抗变压器的继电保护方案等实现变阻抗节能变压器的关键技术进行了详细阐述。研究结果表明,所提出的变阻抗变压器实现了快速开关型限流装置与变压器的一体化设计以及阻抗的自主调节,降低了短路电流对变压器的冲击及损耗。

英文摘要：

With the development of power grid scale and the continuous rise of power load level, the short-circuit current will increase, which seriously threatens the safe operation of electric power system. We proposed a new technique of energy-saving transformer possessing variable impedance. This technique combined advantages of the high impedance transformer and current-limiting reactor, which were commonly used to limit short-circuit current of power transformer. Firstly, we introduced the principle of the proposed variable impedance transformer. Then we discussed the key technique and characteristics of the variable impedance energy-saving transformer in detail, including the design of current-limiting reactor, the high-speed interrupting technique, the current-limiting effect of transformer short-circuit current, the transient overvoltage analysis and the relay protection scheme for variable impedance transformer. The analysis results show that the proposed variable impedance transformer can realize integrated design and self-regulation of impedance, and reduce the impact and loss of short-circuit on transformer.