The most important elements of “intellectual networks” (Smart Grid) are the systems of monitoring the parameters of electrical equipment. Information-measuring systems (IMS), which described in this paper, were prop...The most important elements of “intellectual networks” (Smart Grid) are the systems of monitoring the parameters of electrical equipment. Information-measuring systems (IMS), which described in this paper, were proposed to use together with rapid digital protection against short-circuit regimes in transformer windings. This paper presents an application’s experience of LVI-testing, some results of the use of Frequency Response Analysis (FRA) to check the condition of transformer windings and infra-red control results of electrical equipment. The LVI method and short-circuit inductive reactance measurements are sensitive for detecting such faults as radial, axial winding deformations, a twisting of low-voltage or regulating winding, a losing of winding’s pressing and others.展开更多
针对目前大型变压器加热干燥方法存在的受热不均、绝缘受损等缺点,设计了一种应用于大型变压器干燥的低频加热电源装置,能够在电压等级较低的情况下,为待干燥的负载变压器提供较高的低频加热电流。该低频加热电源采用交-直-交变换原理,...针对目前大型变压器加热干燥方法存在的受热不均、绝缘受损等缺点,设计了一种应用于大型变压器干燥的低频加热电源装置,能够在电压等级较低的情况下,为待干燥的负载变压器提供较高的低频加热电流。该低频加热电源采用交-直-交变换原理,整流侧为2个不控整流桥,逆变侧采用中性点箝位三电平结构;计算偏差中线电流以达到直流电容电压均衡控制,采用无源性控制理论,构建无源性控制模型,确定无源性控制比率,确保了对指令低频电流的渐近跟踪;通过给定的较大指令低频电流,保证负载变压器的加热效果。仿真结果表明,所提控制算法能够在输出低频电流的同时实现直流电压的均衡控制,且稳态特性好、响应速度快、算法实现简单、鲁棒性强。380 V、700 k V·A的工程实际应用表明低频加热电源具有良好的加热效果。展开更多
文摘The most important elements of “intellectual networks” (Smart Grid) are the systems of monitoring the parameters of electrical equipment. Information-measuring systems (IMS), which described in this paper, were proposed to use together with rapid digital protection against short-circuit regimes in transformer windings. This paper presents an application’s experience of LVI-testing, some results of the use of Frequency Response Analysis (FRA) to check the condition of transformer windings and infra-red control results of electrical equipment. The LVI method and short-circuit inductive reactance measurements are sensitive for detecting such faults as radial, axial winding deformations, a twisting of low-voltage or regulating winding, a losing of winding’s pressing and others.
文摘针对目前大型变压器加热干燥方法存在的受热不均、绝缘受损等缺点,设计了一种应用于大型变压器干燥的低频加热电源装置,能够在电压等级较低的情况下,为待干燥的负载变压器提供较高的低频加热电流。该低频加热电源采用交-直-交变换原理,整流侧为2个不控整流桥,逆变侧采用中性点箝位三电平结构;计算偏差中线电流以达到直流电容电压均衡控制,采用无源性控制理论,构建无源性控制模型,确定无源性控制比率,确保了对指令低频电流的渐近跟踪;通过给定的较大指令低频电流,保证负载变压器的加热效果。仿真结果表明,所提控制算法能够在输出低频电流的同时实现直流电压的均衡控制,且稳态特性好、响应速度快、算法实现简单、鲁棒性强。380 V、700 k V·A的工程实际应用表明低频加热电源具有良好的加热效果。
