公开(公告)号：US20050035751A1

公开(公告)日：2005-02-17

申请号：US10494870

申请日：2003-04-17

申请人： Yong-Cheol Kang ,  Sang-Hee Kang ,  Yi-Jae Lim

发明人： Yong-Cheol Kang ,  Sang-Hee Kang ,  Yi-Jae Lim

IPC分类号： H02H1/00 ,  H02H1/04 ,  G01R33/00

CPC分类号： H02H1/046 ,  H02H1/0092

摘要： The present invention relates to a method for preventing the unwanted maloperation of a protective relay system that is caused by the imprecise detection of an actual secondary current value resulting from a measured secondary current being distorted. The method comprises the steps of calculating difference values having at least second order for sampled secondary currents; comparing absolute values of the difference values with a predetermined critical value, and determining a saturation starting moment of a current transformer when one of the absolute values exceeds the predetermined critical value; obtaining a magnetizing current at the saturation starting moment using the difference values if the saturation starting moment is determined, and obtaining a magnetic flux value in a steel core of the current transformer from a magnetization curve using the magnetizing current; calculating a magnetic flux value at a time after the saturation starting moment using a secondary current value measured at that time and the magnetic flux value obtained at the saturation starting moment so as to obtain a secondary current value consistent with a current transformation ratio at that time; obtaining a magnetizing current at that time from the magnetization curve using the magnetic flux value calculated at that time; and obtaining the secondary current value consistent with the current transformation ratio by adding the obtained magnetizing current and the measured secondary current value.

摘要翻译： 本发明涉及一种用于防止由于测量的二次电流失真导致的实际二次电流值的不精确检测而导致的保护继电器系统的不期望的误动作的方法。 该方法包括以下步骤：计算具有至少二次采样二次电流的差值; 将所述差值的绝对值与预定临界值进行比较，以及当绝对值之一超过预定临界值时确定电流互感器的饱和开始时刻; 如果确定饱和起动矩，则使用差值获得在饱和起动时刻的磁化电流，并且使用磁化电流从磁化曲线获得电流互感器的钢芯中的磁通量值; 使用该时刻测定的二次电流值和饱和开始时刻得到的磁通值计算饱和开始时刻之后的时间的磁通值，以获得与当时的当前变换比一致的二次电流值 ; 使用当时计算出的磁通值，从磁化曲线获得此时的磁化电流; 并且通过将获得的磁化电流和所测量的二次电流值相加来获得与电流变换比一致的二次电流值。

公开(公告)号：US07103485B2

公开(公告)日：2006-09-05

申请号：US10494870

申请日：2003-04-17

申请人： Yong-Cheol Kang ,  Sang-Hee Kang ,  Yi-Jae Lim

发明人： Yong-Cheol Kang ,  Sang-Hee Kang ,  Yi-Jae Lim

IPC分类号： G06F17/13

CPC分类号： H02H1/046 ,  H02H1/0092

摘要： A method for preventing the unwanted maloperation of a protective relay system that is caused by the imprecise detection of an actual secondary current value resulting from a measured secondary current being distorted comprises the steps of calculating difference values for sampled secondary currents; comparing absolute values of the difference values with a predetermined critical value, and determining a saturation starting moment of a current transformer when one of the absolute values exceeds the predetermined critical value; obtaining a magnetizing current at the saturation starting moment using the difference values if the saturation starting moment is determined, and obtaining a magnetic flux value in a steel core of the current transformer from a magnetization curve using the magnetizing current; calculating a magnetic flux value at a time after the saturation starting moment using a secondary current value measured at that time and the magnetic flux value obtained at the saturation starting moment so as to obtain a secondary current value consistent with a current transformation ratio at that time; obtaining a magnetizing current at that time from the magnetization curve using the magnetic flux value calculated at that time; and obtaining the secondary current value consistent with the current transformation ratio by adding the obtained magnetizing current and the measured secondary current value.

摘要翻译： 一种用于防止由测量的二次电流失真导致的实际二次电流值的不精确检测引起的保护继电器系统的不期望的误操作的方法包括以下步骤：计算采样次级电流的差值; 将所述差值的绝对值与预定临界值进行比较，以及当绝对值之一超过预定临界值时确定电流互感器的饱和开始时刻; 如果确定饱和起动矩，则使用差值获得在饱和起动时刻的磁化电流，并且使用磁化电流从磁化曲线获得电流互感器的钢芯中的磁通量值; 使用该时刻测定的二次电流值和饱和开始时刻得到的磁通值计算饱和开始时刻之后的时间的磁通值，以获得与当时的当前变换比一致的二次电流值 ; 使用当时计算出的磁通值，从磁化曲线获得此时的磁化电流; 并且通过将获得的磁化电流和所测量的二次电流值相加来获得与电流变换比一致的二次电流值。