在传统的电表中,采样和数据处理模块用于计算测量值和电能,电压和电流电路直接或通过电磁变压器与电表连接,因而对数字电能计量系统进行研究有重要意义.本文通过与传统计量系统的比较,讨论了数字计量系统的应用结构和特点,给出了数字电能表的溯源模型,并通过一系列测试对数字电表的计量特性进行了检验研究,提出了有关检测项目、标准定量值追踪、转移方法和计量表分级,最后对误差结果进行可视化.验证系统性能表明,该方法可以有效地解决数字电表的验证和追溯问题.

The characteristic parameters of the grounding grid include resistance of grounding grid,connective resistance,step voltage and touch voltage etc.For evaluating the security,the method that compares of the single characteristic parameter and the prescriptive threshold value is employed.But now there is no intact method that can be used for evaluating the status of current grounding grid.The model of grounding grid analytic hierarchy is founded based on fuzzy analytic hierarchy process(FAHP),combining the initial parameters with the propositional parameters of excess in the standard make up of the five projects in the bottom of FAHP model.Later,the excellent element combination of the double matrix are founding using the iterative of the tabu search,the eigenvectors of the biggest eigenvalue,as well as ratio coefficient,are calculated after the normal change.Finally,the new elements of the double matrix are calculated based the planar linear function adopting the current measurement parameters of the substation grounding grid,and gain the result of the evaluation.The analytic results of the actual example show the method of the evaluation is accurate and feasible.

The main circuit current flow process in single-phase full-bridge Distribution Static Synchronous Compensator(DSTATCOM) is analyzed in detail.The dual-target control system structure is introduced.To achieve the damping control,an auxiliary control signal is added to a fixed voltage reference to regulate the voltage in DSTATCOM AC side.The auxiliary control signal is the measurement amount corresponding to the active and frequency change in the power system.The auxiliary control signal makes the voltage change in the way as expected,increasing the system damping.For the reactive power reserves control,the automatic control strategy of the adjusting DSTATCOM working point can maintain the scheduled reactive power reserves.In this manner,DSTATCOM has the greatest dynamic control capacity,and retains sufficient dynamic reactive power reserves in steady state.