提升变压器二次侧电压节能

油井变压器送电至用电设备,必须经过用电系统的各个电气设备及元件,电流通过这些电气设备及元件时,将不可避免地产生电能损耗。在输电距离和输送功率一定的条件下,电力网电压越高,则电流愈小,变压器、电动机以及敷设的供配电线路中的功率损耗、电能损耗也就越小。据此,江汉采油厂作好系统状况摸底工作,对其配电系统进行提升变压器二次侧电压改造,既解决了节能技改与资金紧张的矛盾,又取得了非常好的节能效果。

超高功率电弧炉变压器的设计

提出了一种新的高阻抗电弧炉变压器二次电压和最大额定电流的设计方法.熔末升温期"甩抗"后,为保证电效率最大,即电弧电压始终处在泡沫渣下的峰值,且充分发挥变压器能力,就必须对分档电压和最大额定电流进行合理的设计."甩抗"后,根据泡沫渣最大高度、功率因数、变压器额定容量等约束条件,建立了变压器分档电压和最大额定电流的设计原则,使变压器利用率和电弧功率达到最大,缩短冶炼周期.同时提出了变压器容量和最高、最低二次电压的设计方案.对80 t高阻抗电弧炉设计参数和理论运行参数进行分析,结果表明:分档电压设计在734 V为最佳,超过734 V时,变压器的最大额定电流成为提高电弧功率的限制性环节.

Buck converter stability techniques for secondary filters and adaptive voltage positioning

To reduce output voltage noise and improve dynamic response performance,this study designed a buck converter on the basis of secondary filters and adaptive voltage positioning(AVP).A hybrid control method was proposed for the compensation of the secondary filter.The introduction of a high-frequency feedback path,in addition to the traditional feedback path,effectively improved the influence of the secondary filter on the loop stability and direct current regulation performance.A small-signal model of the buck converter based on the proposed control method was derived,and the stability and selection of control parameters were analyzed.AVP is realized using an easy-to-implement and low-cost control method that was proposed to improve dynamic response performance by changing the low-frequency gain of the control loop and load regulation of the output voltage.The experimental results of the buck converter showed that the proposed method effectively reduced the output voltage noise by 50%and improved the dynamic response capability to meet the target requirements of mainstream electronic systems.