由于DCS控制器中电表传感器在计量检测过程中,传统的B-MAC-DCS协议能耗和丢包率较高,无法缓解汇聚节点的漏斗效应,导致在远程抄表过程中传感器计量误差增大。提出一种机械电表接触传感器计量误差检测方法。采用小波基函数对DCS控制器中...由于DCS控制器中电表传感器在计量检测过程中,传统的B-MAC-DCS协议能耗和丢包率较高,无法缓解汇聚节点的漏斗效应,导致在远程抄表过程中传感器计量误差增大。提出一种机械电表接触传感器计量误差检测方法。采用小波基函数对DCS控制器中的接触传感器计量数据抗干扰处理,并通过动态选取阈值的方法,对经过小波变换后的数据去除噪声。使用低功耗自适应集簇分层型(low energy adaptive clustering hierarchy,LEACH)协议分簇代替传统的B-MAC协议;根据簇内监测值,引入阈值分析方法获取传感器计量指标,并将其作为判定依据进行误差检测,根据计量指标的变化情况判断是否存在计量误差。实验结果表明,所提方法可以准确且有效检测出机械电表接触传感器计量误差,解决DCS中机械电表的运行隐患问题。展开更多
以某型号家用电动汽车的设计制造为研究背景,研究了作为动力系统的无传感器无刷直流轮毂电机(Brushless DC Motor,简称BLDCM)的起动控制策略。提出了基于反电势法的转子位置检测方法和三段式起动控制方法,并根据实际电机控制实验对上述...以某型号家用电动汽车的设计制造为研究背景,研究了作为动力系统的无传感器无刷直流轮毂电机(Brushless DC Motor,简称BLDCM)的起动控制策略。提出了基于反电势法的转子位置检测方法和三段式起动控制方法,并根据实际电机控制实验对上述方法进行了改进,取得了良好的控制效果。展开更多
针对无刷直流电机无位置传感器换相位置检测存在较大误差的问题,提出了一种基于线电压差分法的无刷直流电机(brushless DC motors,BLDCM)换相误差补偿新方法。利用线电压差值作为反馈量,通过PI调节器确定补偿角度β,因此确定最终的延时...针对无刷直流电机无位置传感器换相位置检测存在较大误差的问题,提出了一种基于线电压差分法的无刷直流电机(brushless DC motors,BLDCM)换相误差补偿新方法。利用线电压差值作为反馈量,通过PI调节器确定补偿角度β,因此确定最终的延时角度,利用基于(90°-α)的换相信号补偿策略,最终达到精确换相的目的。仿真验证了该方法可以对转子位置误差进行实时、有效地补偿,提高了电机的性能。展开更多
With the rapid development of the direct current(DC)distribution network,DC voltage measurement technology is increasingly important to ensure safe operation in the distribution network.The measurement accuracy of the...With the rapid development of the direct current(DC)distribution network,DC voltage measurement technology is increasingly important to ensure safe operation in the distribution network.The measurement accuracy of the traditional sensor based on resistance dividers decreases over time because the resistors age due to temperature and electromagnetic radiation.To address this problem,a novel type of medium-voltage DC voltage sensor with self-correction ability is presented in this paper.A resistor with large R_(H)is connected in series with RK and R_(G),i.e.two precise resistors with low resistance,to transform the measured medium voltage into low voltage.Among these three resistors in the divider,R_(H)connects with the measured medium DC line,while R_(G)connects with the ground.An electronic switch,K,is paralleled with RK,the precise resistor at the middle position.Generally,the state of the electronic switch is off,and the current flows through RK.Medium DC voltage can be measured according to the voltage on R_(G)with the divider ratio.When the sensor needs self-correction,the electronic switch will be controlled by FPGA(Field Programmable Gate Array)to turn it off and on;therefore,two values of low voltage can be obtained using time-sharing sampling.Two equations can be built according to the divider principle,and R_(H)in the divider can be evaluated by solving the equations.As a result,the measurement error caused by the change in R_(H)can be avoided.Finally,the medium-voltage DC sensor developed in this paper has been tested at the Institute of High Voltage,Wuhan,China.The experimental results show that the sensor can perform self-correction without manual operation,and the sensor’s accuracy can reach 0.12%.Sensors with a self-calibration function can realize long-term high-precision measurement without manual maintenance,showing a good application prospect.展开更多
文摘由于DCS控制器中电表传感器在计量检测过程中,传统的B-MAC-DCS协议能耗和丢包率较高,无法缓解汇聚节点的漏斗效应,导致在远程抄表过程中传感器计量误差增大。提出一种机械电表接触传感器计量误差检测方法。采用小波基函数对DCS控制器中的接触传感器计量数据抗干扰处理,并通过动态选取阈值的方法,对经过小波变换后的数据去除噪声。使用低功耗自适应集簇分层型(low energy adaptive clustering hierarchy,LEACH)协议分簇代替传统的B-MAC协议;根据簇内监测值,引入阈值分析方法获取传感器计量指标,并将其作为判定依据进行误差检测,根据计量指标的变化情况判断是否存在计量误差。实验结果表明,所提方法可以准确且有效检测出机械电表接触传感器计量误差,解决DCS中机械电表的运行隐患问题。
文摘针对无刷直流电机无位置传感器换相位置检测存在较大误差的问题,提出了一种基于线电压差分法的无刷直流电机(brushless DC motors,BLDCM)换相误差补偿新方法。利用线电压差值作为反馈量,通过PI调节器确定补偿角度β,因此确定最终的延时角度,利用基于(90°-α)的换相信号补偿策略,最终达到精确换相的目的。仿真验证了该方法可以对转子位置误差进行实时、有效地补偿,提高了电机的性能。
基金supported by the National Key Research and Development Program of China(2018YFB0904702).
文摘With the rapid development of the direct current(DC)distribution network,DC voltage measurement technology is increasingly important to ensure safe operation in the distribution network.The measurement accuracy of the traditional sensor based on resistance dividers decreases over time because the resistors age due to temperature and electromagnetic radiation.To address this problem,a novel type of medium-voltage DC voltage sensor with self-correction ability is presented in this paper.A resistor with large R_(H)is connected in series with RK and R_(G),i.e.two precise resistors with low resistance,to transform the measured medium voltage into low voltage.Among these three resistors in the divider,R_(H)connects with the measured medium DC line,while R_(G)connects with the ground.An electronic switch,K,is paralleled with RK,the precise resistor at the middle position.Generally,the state of the electronic switch is off,and the current flows through RK.Medium DC voltage can be measured according to the voltage on R_(G)with the divider ratio.When the sensor needs self-correction,the electronic switch will be controlled by FPGA(Field Programmable Gate Array)to turn it off and on;therefore,two values of low voltage can be obtained using time-sharing sampling.Two equations can be built according to the divider principle,and R_(H)in the divider can be evaluated by solving the equations.As a result,the measurement error caused by the change in R_(H)can be avoided.Finally,the medium-voltage DC sensor developed in this paper has been tested at the Institute of High Voltage,Wuhan,China.The experimental results show that the sensor can perform self-correction without manual operation,and the sensor’s accuracy can reach 0.12%.Sensors with a self-calibration function can realize long-term high-precision measurement without manual maintenance,showing a good application prospect.
