JPH04244725A - Overcurrent relay device - Google Patents

Abstract

PURPOSE:To easily obtain sufficient cooperation between devices for overcurrent protection by obtaining a time limit characteristic curve by combining each characteristic in accordance with an overcurrent protective area and making the protective area of each overcurrent relay device clear on the basis of a fault current value. CONSTITUTION:The dividing number for dividing the area of current values which becomes an overcurrent protective range by means of a division selecting means 3 is transmitted to a time limit characteristic curve deciding means 4. The means 4 divides time limit characteristics, such as super-anti-time limit characteristics, etc., stored in a time limit characteristic storing means 2 by a selected dividing number. When individual divided time limit characteristics are appropriately selected on the basis of the system conditions of the locations where overcurrent relay devices are installed and combined in corresponding to a current value area, a time limit characteristic curve is obtained and the obtained curve is set to an operating characteristic curve setting means 6. A momentary operation characteristic means 5 sets a momentary operating characteristic to an operating curve setting means 6.

Description

[Detailed description of the invention]

0001

[Industrial Field of Application] The present invention relates to a static overcurrent relay device that protects a power system from overcurrent based on a predetermined operating characteristic curve, and particularly relates to a static overcurrent relay device that protects a power system from overcurrent based on a predetermined operating characteristic curve. The present invention relates to an overcurrent relay device that can sufficiently and easily coordinate overcurrent protection between devices.

0002

[Prior Art] Various types of protective relay devices have been used to protect electric power systems from accidents. Static overcurrent relay devices are often used. This overcurrent relay device usually has a predetermined operating characteristic curve such as a time limit characteristic, and protects the system from overcurrent based on this.

By the way, in this type of overcurrent relay device, its operating characteristic curve is adjusted to the load characteristics, such as ultra-reactive time characteristic, strong reaction time-limited characteristic, long reaction time-limited characteristic, normal reverse time-limited characteristic, and limited time-limited characteristic. It is now possible to select characteristics. In this case, these characteristics have one type of curve, and the time characteristics and current characteristics are changed by setting the tap or time dial.

However, if the time-limiting characteristics are selected using this method, if the overcurrent relay devices are connected in series in multiple stages due to the distribution line system, overcurrent protection of the overcurrent relay devices will be insufficient. Coordination can be very difficult. In other words, if a series of instrument current transformers with the same current transformation ratio are used to introduce current into an overcurrent relay device, it will be difficult to set the tap or time dial. It is from.

[0005]

[Problems to be Solved by the Invention] As described above, in conventional overcurrent relay devices, when overcurrent relay devices are installed in series, overcurrent There was a problem in that it was difficult to coordinate current protection.

An object of the present invention is to provide an overcurrent relay device that can sufficiently and easily coordinate overcurrent protection between devices even when the devices are installed in series. There is a particular thing.

[0007]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a static overcurrent relay device that performs operation determination based on a predetermined operating characteristic curve and protects a power system from overcurrent. of,

[0008] The time-limiting characteristic storage means stores a plurality of time-limiting characteristics; the division selection means selects the number of divisions for dividing the current value region that is the range of overcurrent protection into predetermined steps; and the time-limiting characteristic storage means Each of the stored time-limiting characteristics is divided according to the number of divisions selected by the division selection means, and each divided time-limiting characteristic is divided based on the system conditions of the part where the overcurrent relay device main body is installed. Select as appropriate,
A time-limit characteristic curve determining means obtains a time-limit characteristic curve by combining these in correspondence with the current value region, and a time-limit characteristic curve determined by the time-limit characteristic curve determining means is combined with instantaneous operation characteristics based on the system conditions to finalize the time limit characteristic curve. and operating characteristic curve setting means for obtaining and setting a typical operating characteristic curve.

[0009]

[Operation] Therefore, in the overcurrent relay device of the present invention,
By appropriately combining multiple time-limiting characteristics depending on the overcurrent protection area to obtain a time-limiting characteristic curve, the protection range of each overcurrent relay device can be clarified based on the fault current value, and the mutual overcurrent relay device Current protection coordination can be sufficiently and easily achieved.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram showing an example of the configuration of an overcurrent relay device according to the present invention. As shown in FIG. 1, the overcurrent relay device of this embodiment includes a static overcurrent relay 1,
It comprises a time limit characteristic storage means 2, a division selection means 3, a time limit characteristic curve determination means 4, an instantaneous operation characteristic setting means 5, and an operation characteristic curve setting means 6.

[0012] Here, the overcurrent relay 1 inputs a current b extracted from the electric power system by an instrument current transformer (not shown), performs an operation judgment based on a set operating characteristic curve, and This protects the device from overcurrent. Further, the time characteristic storage means 2 stores in advance a super anti-time characteristic A, a strong anti-time characteristic B, a long anti-time characteristic C, a normal anti-time characteristic D, and a fixed time characteristic E. Furthermore, the division selection means 3 selects the number of divisions n for dividing the current value region that is the range of overcurrent protection into predetermined stages. Furthermore, the time characteristic curve determining means 4 determines the super anti-time characteristic A, the strong anti-time characteristic B, the long anti-time characteristic C, the normal anti-time characteristic D, and the fixed time characteristic E stored in the time characteristic storage means 2. Number of divisions n selected by division selection means 3
Based on the system condition a of the location where this overcurrent relay device is installed, the divided individual time-limiting characteristics A to E are appropriately selected and assembled in accordance with the current value range. Together, a time characteristic curve is obtained.

On the other hand, the instantaneous operating characteristic setting means 5 is for setting the instantaneous operating characteristic based on the system condition a. Further, the operating characteristic curve setting means 6 combines the time-limited characteristic curve determined by the time-limited characteristic curve determining means 4 with the instantaneous operating characteristic set by the instantaneous operating characteristic setting means 5 to obtain a final operating characteristic curve. , which is set in the overcurrent relay 1. Next, the operation of the overcurrent relay device of this embodiment configured as above will be explained.

In FIG. 1, the division selection means 3 selects a range of current values within the range of overcurrent protection (for example, the range of current b extracted by an instrument current transformer is set to 0 to 5 A).
The number of divisions n for dividing into predetermined stages (for example, n=5
) is selected by the time limit characteristic curve determining means 4, the time limit characteristic curve determining means 4 calculates the super anti-time characteristic A, the strong anti-time characteristic B, the long anti-time characteristic C, which are stored in the time limit characteristic storage means 2. The normal anti-time characteristic D and the fixed time characteristic E are divided according to the selected division number n. That is, in this example, each time limit characteristic is 0 to 1A, 1 to 2A, 2 to 3A, and 3 to 4A.
, 4 to 5A. Then, these divided individual time-limiting characteristics A to E are appropriately selected based on the system condition a of the location where the present overcurrent relay device is installed, and are combined in correspondence with the current value range. A time-limiting characteristic curve is obtained and selected by the operating characteristic curve setting means 6. That is, for example, in the region of 0 to 1 A, there is a long reaction time characteristic,
The normal inverse time characteristic is selected in the 1 to 2 A region, and the fixed time characteristic is selected in the 2 to 3 A region and combined to obtain a time limited characteristic curve in the 0 to 3 A region.

On the other hand, the instantaneous operating characteristic setting means 5 sets the instantaneous operating characteristic in the operating characteristic curve setting means 6 based on the system condition a. In this example, an instantaneous operation characteristic that instantaneously operates in the range of 3 to 5 A is set. Then, the operating characteristic curve setting means 6 combines the time-limited characteristic curve determined by the time-limited characteristic curve determining means 4 with the instantaneous operating characteristic set by the instantaneous operating characteristic setting means 5 to obtain a final operating characteristic curve. is obtained, and this is set in the overcurrent relay 1 as its operating characteristic curve. That is, in this example, the range of 0 to 1A is a long reverse time characteristic, the range of 1 to 2A is a normal reverse time characteristic, the region of 2 to 3A is a fixed time characteristic, and the range of 3 to 5A is a fixed time characteristic.
An operating characteristic curve is set for the overcurrent relay 1 such that the region operates with instantaneous operating characteristics. In the overcurrent relay 1, the power system is protected from overcurrent by determining the operation based on the set operating characteristic curve.

As described above, the protection range of each overcurrent relay installed in the power system can be clarified. Next, a specific example will be described in which three overcurrent relays are installed. FIG. 2 is a diagram showing an example of overcurrent protection coordination characteristics, in which the horizontal axis represents the current axis, and the vertical axis represents the time axis.

In FIG. 2, R1 is the operating characteristic curve of the lower overcurrent relay installed on the lower distribution line, and R2 is the operating characteristic curve of the intermediate overcurrent relay installed on the intermediate distribution line.
R3 indicates the operating characteristic curve of the upper overcurrent relay installed in the upper distribution line. That is, the operating characteristic curve R1 of the lower overcurrent relay is a combination of the normal inverse time characteristic and the instantaneous operating characteristic. Further, the operating characteristic curve R2 of the intermediate overcurrent relay is a combination of the long reverse time characteristic, the normal reverse time characteristic, the fixed time characteristic, and the instantaneous operation characteristic. Further, the operating characteristic curve R3 of the upper overcurrent relay is a combination of the long reverse time characteristic, the normal reverse time characteristic, the fixed time characteristic, and the instantaneous operation characteristic.

On the other hand, the overcurrent value I1 becomes an overload protection unit and is detected in the overload region of the lower overcurrent relay, and the operating characteristics of the intermediate overcurrent relay are such that the overcurrent value I1 is not detected. It is a time-limited characteristic. In addition, since the overcurrent value I2 is a value in the short-circuit current detection region of the lower overcurrent relay, it is detected in the instantaneous operation region, and as a backup protection region, the operating characteristic of the intermediate overcurrent relay is given a limited time characteristic. . moreover,
The overcurrent value I3 is detected in the instantaneous operation region in the protection detection range of the intermediate overcurrent relay, and as a back-up protection region, the upper overcurrent relay has a limited time characteristic as the operating characteristic. As described above, by selecting characteristics according to each overcurrent protection area, sufficient overcurrent protection coordination can be achieved.

As described above, the overcurrent relay device of this embodiment receives as input the current b extracted from the power system by the instrument current transformer, and determines its operation based on the set operating characteristic curve. The overcurrent relay 1 that protects the power system from overcurrent, the long reaction time characteristic A, the strong reaction time characteristic B, the long reaction time characteristic C, the normal reaction time characteristic D, and the fixed time characteristic E are memorized in advance. time-limiting characteristic storage means 2, division selection means 3 for selecting the number of divisions n for dividing the current value region that is the range of overcurrent protection into predetermined stages, and time-limiting characteristic storage means 2. Super anti-time characteristic A, strong anti-time characteristic B, long anti-time characteristic C, normal anti-time characteristic D, limited anti-time characteristic E
is divided according to the number of divisions n selected by the division selection means 3, and the divided individual time-limiting characteristics A to E are determined as appropriate based on the system condition a of the location where the present overcurrent relay device is installed. a time limit characteristic curve determining means 4 which obtains a time limit characteristic curve by selecting and combining them in correspondence with the current value region; an instantaneous operation characteristic setting means 5 which sets an instantaneous operation characteristic based on the system condition a; The instantaneous operating characteristic set by the instantaneous operating characteristic setting means 5 is combined with the time limit characteristic curve determined by the characteristic curve determining means 4 to obtain a final operating characteristic curve, and this is set in the overcurrent relay 1. It is constructed from an operating characteristic curve setting means 6.

Therefore, a time characteristic curve can be obtained by suitably combining the super reaction time characteristic, strong reaction time characteristic, long reaction time characteristic, normal reaction time characteristic, and fixed time characteristic depending on the overcurrent protection area. Even when overcurrent relay devices are installed in a series, the protection range of each overcurrent relay device can be clarified based on the fault current value, and overcurrent protection coordination between overcurrent relay devices can be ensured. Moreover, it can be easily removed.

[0021]

[Effects of the Invention] As explained above, according to the present invention, the ultra-reverse time characteristic, the strong reverse time-limit characteristic, the long reaction time characteristic, the normal reverse time characteristic, and the fixed time characteristic are appropriately combined depending on the overcurrent protection area. The time-limiting characteristic curve was obtained using the method, and the protection range of each overcurrent relay device was clarified based on the fault current value.
Even when devices are installed in series, it is possible to provide an extremely overcurrent relay device that can sufficiently and easily coordinate overcurrent protection between devices.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of an overcurrent relay device according to the present invention.

FIG. 2 is a diagram showing an example of overcurrent protection cooperation characteristics in the same embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1... Overcurrent relay, 2... Time limit characteristic storage means, 3... Division selection means, 4... Time limit characteristic curve determining means, 5... Instantaneous operation characteristic setting means, 6... Operating characteristic curve setting means.

Claims (1)

[Claims] 1. A static overcurrent relay device that protects a power system from overcurrent by making an operation determination based on a predetermined operating characteristic curve, comprising: a time-limiting characteristic storage means for storing a plurality of time-limiting characteristics; division selection means for selecting the number of divisions for dividing a current value region that is a range of current protection into predetermined stages, and each time-limiting characteristic stored in the time-limiting characteristic storage means being selected by the division selection means. The method is divided according to the number of divisions determined, and the divided individual time-limiting characteristics are appropriately selected based on the system conditions of the location where the overcurrent relay device main body is installed, and are made to correspond to the current value region. and a time-limit characteristic curve determining means for obtaining a time-limit characteristic curve by combining the time-limit characteristic curve determining means with the instantaneous operating characteristics based on the system conditions to obtain a final operating characteristic curve. An overcurrent relay device comprising: an operating characteristic curve setting means for determining and setting an operating characteristic curve.