配电变压器短路和开路损耗在线测量系统

针对配电变压器短路损耗和空载损耗离线测量影响供电连续性的问题,提出一种新的变压器损耗在线测量方法并设计了在线测量系统.依据变压器等效电路模型建立变压器短路阻抗与其一、二次侧电压、电流的关系,并推导出了短路阻抗与空载和短路损耗之间的关系.采用线性拟合方法拟合在线采集到的配电变压器相电压和相电流值来实现短路电阻的在线测量,进而实现变压器短路和空载损耗的在线测量.给出一种新的变压器损耗在线测量方法,建立一套变压器损耗在线检测系统,并在Matlab/SIMULINK仿真平台上进行仿真研究.结果显示,使用该方法计算出的空载损耗和短路损耗分别小于或等于0.4％和2.12％,验证了该方法的有效性和准确性.

System of online measuring short-circuit loss and open-circuit loss of distribution transformer

Considering the fact that off-line measurement of short-circuit loss and open-circuit loss of distribution transformer(DT) is not cost-effective for the reliability of the power supply,a novel method for on-line measuring the losses of DT was proposed and the corresponding on-line measuring system was designed.Firstly,the relation expression of the short-circuit impedance with respect to the voltage,current of the primary and secondary side as well as the relations between the losses and the short-circuit impedance are developed based on the analysis of the equivalent circuit model of DT,respectively.Then,with the value of online voltage and current of the transformer,the online short-circuit impedance is computed by using linear fitting technique.Furthermore,according to the developed relation,the losses of DT can be acquired by using the obtained short-circuit impedance.A series of numerical simulation has been carried out on Matlab/SIMULINK to verify the feasibility and effectiveness of the proposed method with high accuracy.