公开(公告)号：US5475314A

公开(公告)日：1995-12-12

申请号：US433540

申请日：1995-05-02

申请人： Naoki Kunihiro ,  Tadashi Naito

发明人： Naoki Kunihiro ,  Tadashi Naito

IPC分类号： G01R31/00 ,  G01R31/02 ,  H02H3/52 ,  H02J3/01 ,  G01R23/167

CPC分类号： H02J3/01 ,  G01R31/02 ,  Y02E40/40 ,  Y02P80/112

摘要： A method for improving accuracy of estimating natural frequency of a distribution system. The estimation is performed in order to identify a rectifier load that generates harmonics due to commutation oscillation. It includes the steps of measuring a charging current flowing into a power factor improving capacitor to obtain first data, removing fundamental frequency from the first data to obtain second data, determining, from the second data, a first time at which the amplitude of commutating oscillation components takes a maximum value, picking up third data in the interval beginning from the first time and ending at a second time later than the first time by T/N, where T is the period of the fundamental frequency, and N is the number of rectifier phases, performing frequency analysis on the third data to form fourth data by expanding the third data into a Fourier series, and determining a local peak frequency, that is, the natural frequency in the fourth data. This prevents frequency components of particular orders from being emphasized, and reduces interference between the commutation oscillations, thereby making it possible to obtain a local peak value, that is, the natural frequency with ease at high accuracy.

摘要翻译： 一种提高分配系统固有频率估计精度的方法。 执行该估计以便识别由于换向振荡而产生谐波的整流器负载。 它包括测量流入功率因数改善电容器的充电电流以获得第一数据，从第一数据中去除基频以获得第二数据的步骤，从第二数据确定换向振荡幅度的第一时间 组件获取最大值，从第一次开始的间隔中拾取第三个数据，并且比第一次晚一个时间结束T / N，其中T是基本频率的周期，N是 对第三数据执行频率分析，通过将第三数据扩展为傅立叶级数来形成第四数据，以及确定本地峰值频率，即第四数据中的固有频率。 这防止强调特定次序的频率分量，并且减小换向振荡之间的干扰，从而可以以高精度容易地获得局部峰值，即固有频率。

公开(公告)号：US5473255A

公开(公告)日：1995-12-05

申请号：US110227

申请日：1993-08-23

申请人： Naoki Kunihiro ,  Tadashi Naito

发明人： Naoki Kunihiro ,  Tadashi Naito

IPC分类号： G01R31/00 ,  G01R31/02 ,  H02H3/52 ,  H02J3/01 ,  G01R23/167

CPC分类号： H02J3/01 ,  G01R31/02 ,  Y02E40/40 ,  Y02P80/112

摘要： A method for improving accuracy of estimating natural frequency of a distribution system. The estimation is performed in order to identify a rectifier load that generates harmonics due to commutation oscillation. It includes the steps of measuring a charging current flowing into a power factor improving capacitor to obtain first data, removing fundamental frequency from the first data to obtain second data, determining, from the second data, a first time at which the amplitude of commutating oscillation components takes a maximum value, picking up third data in the interval beginning from the first time and ending at a second time later than the first time by T/N, where T is the period of the fundamental frequency, and N is the number of rectifier phases, performing frequency analysis on the third data to form fourth data by expanding the third data into a Fourier series, and determining a local peak frequency, that is, the natural frequency in the fourth data. This prevents frequency components of particular orders from being emphasized, and reduces interference between the commutation oscillations, thereby making it possible to obtain a local peak value, that is, the natural frequency with ease at high accuracy.

摘要翻译： 一种提高分配系统固有频率估计精度的方法。 执行该估计以便识别由于换向振荡而产生谐波的整流器负载。 它包括测量流入功率因数改善电容器的充电电流以获得第一数据，从第一数据中去除基频以获得第二数据的步骤，从第二数据确定换向振荡幅度的第一时间 组件获取最大值，从第一次开始的间隔中拾取第三个数据，并且比第一次晚一个时间结束T / N，其中T是基本频率的周期，N是 对第三数据执行频率分析，通过将第三数据扩展为傅立叶级数来形成第四数据，以及确定本地峰值频率，即第四数据中的固有频率。 这防止强调特定次序的频率分量，并且减小换向振荡之间的干扰，从而可以以高精度容易地获得局部峰值，即固有频率。