This paper proposed a new diagnosis model for the stator inter-turn short circuit fault in synchronous generators.Different from the past methods focused on the current or voltage signals to diagnose the electrical fa...This paper proposed a new diagnosis model for the stator inter-turn short circuit fault in synchronous generators.Different from the past methods focused on the current or voltage signals to diagnose the electrical fault,the sta-tor vibration signal analysis based on ACMD(adaptive chirp mode decomposition)and DEO3S(demodulation energy operator of symmetrical differencing)was adopted to extract the fault feature.Firstly,FT(Fourier trans-form)is applied to the vibration signal to obtain the instantaneous frequency,and PE(permutation entropy)is calculated to select the proper weighting coefficients.Then,the signal is decomposed by ACMD,with the instan-taneous frequency and weighting coefficient acquired in the former step to obtain the optimal mode.Finally,DEO3S is operated to get the envelope spectrum which is able to strengthen the characteristic frequencies of the stator inter-turn short circuit fault.The study on the simulating signal and the real experiment data indicates the effectiveness of the proposed method for the stator inter-turn short circuit fault in synchronous generators.In addition,the comparison with other methods shows the superiority of the proposed model.展开更多
局部均值分解(Local mean decomposition,LMD)在分析非线性、非平稳信号时表现出特有的分析能力,能够有效获得非平稳信号的时频特征,但是局部均值分解过程中的端点效应会导致分解结果失真,针对这一问题,从振动信号解调分析角度出发,提...局部均值分解(Local mean decomposition,LMD)在分析非线性、非平稳信号时表现出特有的分析能力,能够有效获得非平稳信号的时频特征,但是局部均值分解过程中的端点效应会导致分解结果失真,针对这一问题,从振动信号解调分析角度出发,提出基于对称差分能量算子解调的局部均值分解端点效应抑制方法,采用局部均值分解方法将原信号分解为一系列单分量信号,然后对每一个单分量信号进行三点对称差分能量算子解调,得到各单分量信号的瞬时幅值和瞬时频率,从而获得原信号的时频分布。为评价该端点效应抑制方法的抑制效果,定义一种评价标准,通过与其他两种端点效应抑制方法进行比较,验证该方法的优越性。仿真和试验结果表明该方法能够有效抑制LMD端点效应,实现旋转机械故障的有效诊断。展开更多
针对配电网行波定位中受噪声干扰导致波头标定困难和传统定位方法不适用于多分支配网结构的问题,提出基于多分辨率奇异值分解-变分模态分解MRSVD-VMD(multi-resolution singular value decomposition-variational mode decomposition)...针对配电网行波定位中受噪声干扰导致波头标定困难和传统定位方法不适用于多分支配网结构的问题,提出基于多分辨率奇异值分解-变分模态分解MRSVD-VMD(multi-resolution singular value decomposition-variational mode decomposition)的自适应波头标定算法和不受行波波速影响的T域定位算法。利用MRSVD和VMD分解故障行波,根据峭度值和峭熵比筛选有效分量,然后通过对称差分能量算子SDEO(symmetrical differencing energy operator)实现波头标定;最后利用行波到达时间筛选故障T域,实现故障点的区段定位和精确测距。仿真结果表明,MRSVD-VMD行波波头标定方法在不同噪声下能有效标定波头,T域定位算法排除波速影响,能实现多分支配电网故障的精确定位。展开更多
基金supported in part by the National Natural Science Foundation of China(52177042)Natural Science Foundation of Hebei Province(E2020502031)+1 种基金the Fundamental Research Funds for the Central Universities(2017MS151),Suzhou Social Developing Innovation Project of Science and Technology(SS202134)the Top Youth Talent Support Program of Hebei Province([2018]-27).
文摘This paper proposed a new diagnosis model for the stator inter-turn short circuit fault in synchronous generators.Different from the past methods focused on the current or voltage signals to diagnose the electrical fault,the sta-tor vibration signal analysis based on ACMD(adaptive chirp mode decomposition)and DEO3S(demodulation energy operator of symmetrical differencing)was adopted to extract the fault feature.Firstly,FT(Fourier trans-form)is applied to the vibration signal to obtain the instantaneous frequency,and PE(permutation entropy)is calculated to select the proper weighting coefficients.Then,the signal is decomposed by ACMD,with the instan-taneous frequency and weighting coefficient acquired in the former step to obtain the optimal mode.Finally,DEO3S is operated to get the envelope spectrum which is able to strengthen the characteristic frequencies of the stator inter-turn short circuit fault.The study on the simulating signal and the real experiment data indicates the effectiveness of the proposed method for the stator inter-turn short circuit fault in synchronous generators.In addition,the comparison with other methods shows the superiority of the proposed model.
文摘局部均值分解(Local mean decomposition,LMD)在分析非线性、非平稳信号时表现出特有的分析能力,能够有效获得非平稳信号的时频特征,但是局部均值分解过程中的端点效应会导致分解结果失真,针对这一问题,从振动信号解调分析角度出发,提出基于对称差分能量算子解调的局部均值分解端点效应抑制方法,采用局部均值分解方法将原信号分解为一系列单分量信号,然后对每一个单分量信号进行三点对称差分能量算子解调,得到各单分量信号的瞬时幅值和瞬时频率,从而获得原信号的时频分布。为评价该端点效应抑制方法的抑制效果,定义一种评价标准,通过与其他两种端点效应抑制方法进行比较,验证该方法的优越性。仿真和试验结果表明该方法能够有效抑制LMD端点效应,实现旋转机械故障的有效诊断。
文摘针对配电网行波定位中受噪声干扰导致波头标定困难和传统定位方法不适用于多分支配网结构的问题,提出基于多分辨率奇异值分解-变分模态分解MRSVD-VMD(multi-resolution singular value decomposition-variational mode decomposition)的自适应波头标定算法和不受行波波速影响的T域定位算法。利用MRSVD和VMD分解故障行波,根据峭度值和峭熵比筛选有效分量,然后通过对称差分能量算子SDEO(symmetrical differencing energy operator)实现波头标定;最后利用行波到达时间筛选故障T域,实现故障点的区段定位和精确测距。仿真结果表明,MRSVD-VMD行波波头标定方法在不同噪声下能有效标定波头,T域定位算法排除波速影响,能实现多分支配电网故障的精确定位。
