为了解决某电站变送器精度校验问题,通过分析相关标准、技术说明书,深入计算确定了变送器精度校验的一套方案。计算及分析结果说明了变送器校验过程应重点分析产品说明书,根据产品特性进行针对性校验,最终才能保证校验结果的准确。

In order to solve the problem about verification of transducer accuracy,the paper analyzes the related standards、product specification,calculates the experimental data,finds out a scheme about verification of transducer accuracy.The experiment and analysis prove that it is important to analyze the product specification and then set a specific scheme.Finally,we can get the accuracy result.

针对变压器变斜率比率制动差动保护制动方程较复杂,校验较困难的问题,从数学角度深入分析各电流之间的数量关系,简化差动电流、制动电流和测试电流之间的关系,提出一种变斜率比率制动差动保护校验的方法,并结合Excel自动计算表格,可以快速准确校验保护的动作曲线,提高校验准确度和校验效率。通过某电站的校验实例验证该方法快捷、准确,接结简便,易于操作,可以校验保护装置的整个工作状态。

Considering that the transformer variable slope ratio restraint differential protection braking e-quation is rather complicated and its check is quite difficult ,the paper analyzes the quantitative relation be-tween various currents ,simplifies the relations between the differential current ,the braking current and the test current and proposes a variable slope ratio restraint differential protection check method from the angle of mathematics .Further the paper uses the Excel automatic calculation form to check the activation curve of the check protection in a quick and accurate way to improve both check accuracy and check effi-ciency .The check living example of a certain hydropower plant proved that the method is quick ,accurate , easy to do connection and to operate and is able to check the whole working condition of the protection de-vice .

采用经典LLR BP算法对低密度奇偶校验（ Low Density Parity Check， LDPC）码译码时，译码复杂度非常高，主要表现在译码时迭代次数过多和每次循环时校验节点的计算复杂度过高。基于以上问题提出一种新的改进型LLR BP译码算法，自适应地实时监控译码是否稳定来降低在低信噪比条件下的译码迭代次数，同时采用函数逼近的方法降低每次循环时校验节点的计算复杂度。仿真结果表明，该算法在译码性能损失不大的情况下可大幅降低LDPC码的译码复杂度。

Classical LLR BP algorithm to decode LDPC involves high complexitybecause of iterations and calculation complexity of horizontal directions in every iteration process. This paper proposes a new modified LLR BP algorithm to monitor whether decoding output is stable or not to decrease iteration times in low signal noise rate.At the same time,Taylor function approximation is adopted to reduce calculation complexity at check codes. Simulations reveal that this proposed method can reduce decode complexity widely for LDPC in the condition of a small decoding performance loss.

分析了现阶段地铁直流系统短路计算存在的问题,对地铁直流供电系统短路计算模型进行了分析与改进,建立了一套符合保护整定和校验要求的故障计算模型。分析了地铁直流系统稳态短路计算误差产生的原因,从机组等效和拐点电流两方面给出了减小误差的方法,并给出了优化后的程序计算流程。介绍了直流侧出口和远端短路暂态电流的计算模型,在此基础上提出了一种通过超调量来区分出口、近端、远端短路故障的方法,以及近端短路暂态电流的计算方法。仿真验证表明,上述计算模型和方法在计算误差和完整性方面满足保护整定与校验要求。

This paper analyzes the problems in short-circuit calculation model of DC traction system, and presents a set of fault calculation process meeting the requirements of protection setting and validation by analyzing different fault calculation models. The reasons for producing calculation errors are analyzed. The method of reducing the calculation error in steady-state short-circuit calculation is presented from two aspects of rectifier unit equivalent and knee current. The optimized calculation process is given. Based on the calculation model of transient current of DC-side output short-circuit and remote short-circuit, the overshoot theory is applied to come up with a new method to identify the output short-circuit, close-up short-circuit, and far end short-circuit, and method of calculating the transient current of close-up short-circuit is proposed. Simulation examples confirm the feasibility and accuracy of the proposed models and methods in meeting the requirements of protection se

提出基于相似度原理异构等效的电能质量监测装置校验信号实现的新方法,通过将监测装置采样信号序列与标准源输出信号序列进行时序平移相似度计算,分析校验信号同步方法和构成;研究异构校验信号输出实现,给出监测装置整点采样和随机采样时异构校验信号输出实现方法。开发了电能质量监测装置校验信号实现软件系统,对监测装置精度进行校准验证,校验结果表明运用此方法能彻底解决标准源输出信号序列与监测装置采样序列无法同步、相邻校准信号之间存在相互干扰等问题,有效的提高了对装置精度检验的准确度和可靠性,对提高电网和用户电能质量监测水平,以及电能质量监测装置技术提升和产业发展起到了积极的促进作用。

A new method of calibration signal implementation in power quality monitoring devices based on heterogeneous equivalence of similarity theory is proposed in the paper. Timing-shift similarity calculation between the sampling signal sequence of the monitoring device and the output signal sequence of standard source has been carried out so as to analyze calibration signal synchronization method and its composition. Output method of heterogeneous calibration signal has been considered in the case of the whole point sampling and random sampling of the monitoring device. In addition, the calibration software about power quality monitoring devices is developed to measure the accuracy of the devices. Calibration results show that the questions of asynchronous between the sampling signal of the monitoring device and the output signal of standard source, and mutual interference between adjacent calibration signals are completely solved, which will greatly improve the accuracy and reliability of