KR102539523B1 - A appartus for caculation parameters of protection coordination of multi circuit breaker - Google Patents

Abstract

An apparatus for automatically calculating multi-circuit breaker protection coordination settings according to an embodiment of the present invention relates to an apparatus for automatically calculating multi-circuit breaker protection coordination settings for underground distribution lines for configuring a RMU (Ring Main Unit). a data input unit that receives inputs of correlational constraints; a data selector selecting a characteristic curve of the multiple circuit breaker for optimal protection coordination of the multiple circuit breaker; an optimization processing unit calculating an optimal time-limited operation parameter and an optimal instantaneous operation parameter of the characteristic curve based on the constraint conditions, the characteristic curve, and a preset objective function; and a data result unit outputting the optimum time limit operation parameter and the optimum instantaneous operation parameter calculated by the optimization process unit.

Description

Multi-circuit breaker protection coordination setting automatic calculation device {A APPARTUS FOR CACULATION PARAMETERS OF PROTECTION COORDINATION OF MULTI CIRCUIT BREAKER}

The present invention relates to an automatic calculation device for protection coordination settings of multiple circuit breakers, and more specifically, to an automatic calculation device for protection coordination settings of multiple circuit breakers capable of automating correction of protection coordination of multiple circuit breakers.

In order to improve supply reliability of underground distribution lines, RMU (Ring Main Unit: switchgear for transformers of power-side switchgear and load-side breaker) is configured by linking the transformer installation section of the underground distribution line with the current open loop method to the power-side multi-circuit breaker breaker for each ground transformer. A plan to change it to , and some underground systems are being piloted and operated.

This is a method of realizing the same function by utilizing the multiple circuit breakers and transformers already in use in underground distribution lines in the main line (or branch line) connection method, which was previously applied only to transformer supply lines of distribution stations for domestic high-reliability power supply.

The multi-circuit breaker to configure the RMU is installed on the ground in the 2.9kV-y underground distribution line and is used for automatic blocking of the fault section of the multi-circuit method, and for classification of lines and branch lines. There are several types, and it is configured to set time-limited operation and instantaneous operation blocking characteristics.

Efforts have been made to expand and apply the IEC curve as well as the conventional standards (N1 to N4) for protection cooperation between protective devices installed on underground distribution lines. The types of characteristic curves (movement curves) have diversified.

The protection device for the high-voltage side of the ground transformer for supplying power to the low-voltage side connects a current-limiting fuse and a switch-type protection device in series to block overload in the transformer or a failure in the low-voltage side.

In order to stably operate the RMU, it is essential to review the protection cooperation with the substation-side circuit breaker, branch line (main line) multi-circuit breaker, ground transformer power supply-side multi-circuit breaker, transformer inrush current, and transformer protection device.

On the other hand, in the case of a multi-circuit breaker that is currently applied, there is a problem in that the distribution automation system cannot immediately detect whether or not there is a failure when an internal failure occurs in a transformer linked to a breaker of the multi-circuit breaker.

In addition, since the operator directly selects the optimal correction parameter for protection cooperation, there is a high possibility that the optimal correction may not be made according to the operator's error in judgment.

On the other hand, the following prior art documents are of a plurality of circuit breakers in a low voltage system capable of protecting cooperation in both directions from the upper side to the lower side or from the lower side to the upper side and minimizing the number of wires for protection cooperation between a plurality of phases and lower circuit breakers. The technical content of the protection cooperation device is disclosed, and the technical gist of the present invention is not disclosed.

The background art of the present invention is disclosed in Republic of Korea Patent Publication No. 10-2019-0105850 (2019.09.18. Publication, protection cooperation device of a plurality of circuit breakers in a low voltage system).

An apparatus for automatically calculating multi-circuit breaker protection coordination settings according to an embodiment of the present invention aims at the following problems in order to solve the above problems.

It is to provide an automatic calculation device for multi-circuit breaker protection coordination settings that can automatically correct a time limit operation parameter and an instantaneous operation parameter for protection coordination of a multi-circuit breaker.

The problems of the present invention are not limited to those mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

An apparatus for automatically calculating multi-circuit breaker protection coordination settings according to an embodiment of the present invention relates to an apparatus for automatically calculating multi-circuit breaker protection coordination settings for underground distribution lines for configuring a RMU (Ring Main Unit). a data input unit that receives inputs of correlational constraints; a data selector selecting a characteristic curve of the multiple circuit breaker for optimal protection coordination of the multiple circuit breaker; an optimization processing unit calculating an optimal time-limited operation parameter and an optimal instantaneous operation parameter of the characteristic curve based on the constraint conditions, the characteristic curve, and a preset objective function; and a data result unit outputting the optimum time limit operation parameter and the optimum instantaneous operation parameter calculated by the optimization process unit.

The constraint conditions are the operation time of the multiple circuit breaker, the time constant product of the multiple circuit breaker, the operation time characteristics of the substation-side circuit breaker, the operation time characteristics of the switch-type protection device inside the ground transformer, the operation time characteristics of the current limiting fuse inside the ground transformer, and It is preferable to be a constraint condition related to at least one of the operating time characteristics according to the inrush current of the ground transformer.

The above constraints are preferably set by the following Equation (1).

<Equation 1>

Here, T _min is the minimum value of the magnetic limit operating time of the multi-circuit breaker, T _max is the maximum value of the magnetic limit operating time of the multi-circuit breaker, T _MWI is the operating time of the multi-circuit breaker, and TDS is the product of the time constant ( Time Dial Setting), TDS _min is the minimum value of the multi-circuit breaker's magnetic limit time constant product, TDS _max is the maximum value of the multi-circuit breaker's magnetic limit time constant product, TDS _MWI is the multi-circuit breaker's time constant product, and T _{S /S CB} is the operating time characteristic of the circuit breaker at the substation, T _STP is the operating time characteristic of the switch-type protection device inside the ground transformer, T _FUSE is the operating time characteristic of the current limiting fuse inside the ground transformer, and T _Tr.Inrush is the inrush of the ground transformer It is the operation time characteristic according to the current, and CTI is the cycle time interval between the multi-circuit breaker and backup device

Preferably, the optimal time-limited action parameter and the optimal instantaneous action parameter are the time-limited action parameter and the instantaneous action parameter when the objective function is maximized, respectively.

The objective function is preferably defined by Equation (2) below.

<Equation (2)>

Here, T _const is the high-current opening operating time of the multi-circuit breaker, that is, the time required due to the physical minimum response characteristics of the multi-circuit breaker, T _delay is the operating delay time of the multi-circuit breaker, and curve is IEC, KEPCO, ANSI, etc. is the multi circuit breaker TC operating curve, α, β, γ and L are the internal parameters of the multi circuit breaker characteristic curve, specifically α, β and L are the relay characteristic values, β is the characteristic curve index, and CT ratio is the instrument and the ratio of the rated primary current and the rated secondary current of the current transformer used for the relay, which is set as the current ratio of the multi-circuit breaker installation location, PS _MWI is the current setting value of the secondary side of the multi-circuit breaker, and I _fault is Fault current, I _pickup is the set value of the operating current of the multi-circuit breaker, and means the primary conversion value through the product of the secondary current (PS _MWI ) of the multi-circuit breaker installation location and the current transformer ratio, and I _pickup1 is the multi-circuit breaker's Instantaneous operation current correction value, I _pickup2 is the multi-circuit breaker instantaneous operation current correction value

According to an embodiment of the present invention, the apparatus for automatically calculating the protection coordination setting value of a multi-circuit breaker automatically calculates and selects the optimal correction parameter selected by the optimization process unit, which has been manually reviewed and set by the user in the past. The reliability of generated alarms can be improved, and furthermore, the effect of improving work efficiency can be expected.

Effects of the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

1 is a diagram showing an example of a characteristic curve of a multi-circuit breaker.
2 is a block diagram briefly showing a conventional multi-circuit breaker protection coordination setting value automatic calculation device.
3 is a block diagram briefly illustrating an apparatus for automatically calculating a multi-circuit breaker protection coordination setting value according to an embodiment of the present invention.
4 is a diagram showing a multi-circuit breaker protection coordination curve for explaining the operation of an automatic calculation device for multi-circuit breaker protection coordination settings according to an embodiment of the present invention.
FIG. 5 is a block diagram showing the detailed configuration of an automatic calculation unit for protection coordination settings in FIG. 3 .
FIG. 6 is a flowchart for explaining the operation of the optimization process unit in FIG. 5 .
7 is a diagram showing a display of an apparatus for automatically calculating multi-circuit breaker protection coordination settings according to an embodiment of the present invention.

With reference to the accompanying drawings, a preferred embodiment according to the present invention will be described in detail, but the same or similar components are assigned the same reference numerals regardless of reference numerals, and redundant description thereof will be omitted.

In addition, in describing the present invention, if it is determined that a detailed description of a related known technology may obscure the gist of the present invention, the detailed description will be omitted. In addition, it should be noted that the accompanying drawings are only for easily understanding the spirit of the present invention, and should not be construed as limiting the spirit of the present invention by the accompanying drawings.

Prior to describing the automatic calculation device for protection coordination settings for multiple circuit breakers according to an embodiment of the present invention, the conventional multiple circuit breaker protection coordination will be described first with reference to FIGS. 1 and 2 .

In the case of correcting the minimum operating current of a multi-circuit breaker according to the standard (short-circuiting of the breaker), it is specified as 50A to 60A, and for this reason, as shown in FIG. 1, for example, the IEC-EI curve is applied When an internal failure occurs in the linked transformer, the switch-type protection device on the high-voltage side of the transformer or the melting of the current limiting fuse operates first.

Due to the above operation, an alarm operation area 11 and an alarm non-operation area 12 of the distribution automation system are formed as shown in FIG. It is impossible to replace the STP or current limiting fuse in a timely manner, and there is a high possibility of civil complaints due to the delay in power failure recovery.

In addition, the time-limit/instantaneous operation parameters of the multi-circuit breaker are corrected according to external factors such as the time-limit/instantaneous operation of the substation-side circuit breaker, delay time set value, inrush current according to the capacity of the ground transformer, combination of STP and current-limiting fuse, etc. at every installation. To be performed, the operation curve of the multi-circuit breaker has an applicable range of time constant product, delay time, and minimum response time for each curve, and a settable step within the range.

As shown in FIG. 2, the existing protection coordination correcting device is configured to include a data acquisition unit 21, a protection coordination review unit 22, and a parameter input unit 23, including the protection coordination review unit 22 and the parameter input unit. It is configured so that the operator actually performs the role of (23) directly.

As a result, since the selection of the optimal correction parameter is made according to the operator's work skill level, it takes a lot of man-hours, and there is a high possibility that the optimal correction will not be made according to the operator's judgment error.

The present invention is to solve the above conventional problems, and as shown in FIG. 3, it is configured to include a data acquisition unit 31, a protection cooperation setting value automatic calculation unit 32, and a parameter input unit 33.

In particular, unlike the conventional protection cooperation review unit 22, the protection cooperation setting point automatic calculation unit 32 performs a function of automatically performing the protection coordination setting value based on the data acquired by the data acquisition unit 31, as shown in FIG. 4 below. to FIG. 7, an apparatus for automatically calculating a multi-circuit breaker protection coordination setting value according to an embodiment of the present invention will be described.

An apparatus for automatically calculating multiple circuit breaker protection coordination settings according to an embodiment of the present invention refers to the automatic calculation unit 32 for protection coordination settings shown in FIG. As a device for automatically calculating circuit breaker protection coordination settings, as shown in FIG.

The data input unit 100 performs a function of receiving constraint conditions correlated with parameters of the multi-circuit breaker, and performs a function of receiving constraint conditions of a heuristic-based optimization algorithm (GA, PSO, HS, Jaya, etc.) , these constraints may be the time limit setting value of the substation-side circuit breaker, the instantaneous operation setting value, and the delay time setting value based on the installation location.

In addition, as shown in FIG. 4, the constraint condition satisfies the protection coordination according to the combination of the inrush current curve 41, the STP characteristic curve 42, and the current limiting fuse characteristic curve 43 according to the capacity of the ground transformer based on the load capacity. It may be that there is a correlation between

The above constraints are summarized in equations as in equation (1) below.

<Equation (1)>

In Equation (1), T _min is the minimum value of the magnetic limit operating time of the multiple circuit breaker, T _max is the maximum value of the magnetic limit operating time of the multiple circuit breaker, T _MWI is the operating time of the multiple circuit breaker, and TDS is Time constant product (Time Dial Setting), TDS _min is the minimum value of the time constant product of the magnetic limit of the multi circuit breaker, TDS _max is the maximum value of the time constant product of the magnetic limit of the multi circuit breaker, and TDS _MWI means the time constant product of the multi circuit breaker do.

And T _{S/S CB} is the operating time characteristic of the circuit breaker at the substation, T _STP is the operating time characteristic of the switch-type protection device inside the ground transformer, T _FUSE is the operating time characteristic of the current limiting fuse inside the ground transformer, and T _Tr.Inrush is It is the operating time characteristic according to the inrush current of the ground transformer, and CTI means the cycle time interval between the multi-circuit breaker and backup equipment.

The data selection unit 200 performs a function of selecting a characteristic curve of the multi-circuit breaker for optimal protection coordination of the multi-circuit breaker, and the optimization process unit 300 performs constraints and data input from the input unit 100. Based on the characteristic curve selected by the selection unit 200 and the objective function set in advance, a function of calculating an optimal time-limited operation parameter and an optimal instantaneous operation parameter of the characteristic curve is performed.

These optimal time-limited action parameters and optimal instantaneous action parameters are the time-limited action parameters and instantaneous action parameters when the objective function is maximized, respectively, and the objective function is defined as Equation (2) below.

<Equation (2)>

In Equation (2), T _const is the high-current opening operating time of the multi-circuit breaker, that is, the time required due to the physical minimum response characteristics of the multi-circuit breaker, T _delay is the multi-circuit breaker operating delay time, and curve is IEC, KEPCO , ANSI, etc. multi circuit breaker TC operation curve, α, β, γ and L are internal parameters of the multi circuit breaker characteristic curve, specifically α, β and L are relay characteristic values, and β is a characteristic curve index.

In addition, the CT ratio is the ratio of the rated primary current and the rated secondary current of the current transformer used for instruments and relays, and is set as the current transformer ratio of the multi-circuit breaker installation location, and PS _MWI is the current set value of the secondary current of the multi-circuit breaker. I _fault is the fault current, I _pickup is the set value of the operating current of the multi-circuit breaker, and means the primary conversion value through the multiplication of the current transformer secondary current (PS _MWI ) and the current transformer ratio at the multi-circuit breaker installation point, and I _pickup1 is the instantaneous operation current correction value of the multiple circuit breaker, and I _pickup2 is the instantaneous operation current correction value of the multiple circuit breaker.

The objective function for deriving the optimal correction curve (T _MWI.curve ) of the multi-circuit breaker belongs to the section of the suitable region part 44 of FIG. The range that can be improved is the case where the size of the objective function satisfying the area of the suitable area unit 44 is the largest.

As shown in FIG. 6, the operation process of the optimization process unit 300 sets the maximum convergence setting condition (Iter _max ) is configured to automatically compute.

The data result unit 400 functions to output the optimal time limit operation parameter and the optimum instantaneous operation parameter calculated in the optimization process unit 300 .

A process of executing the above process through the display of the protection coordination correction device will be described with reference to FIG. 7 .

First, the user inputs the constraints to be considered through the data input window 51, and then clicks the optimization process execution button 52 to execute the optimization process unit, and the objective function is calculated through the above-described algorithm.

Finally, the determined data is output through the optimization result window 53, and the optimized parameters are output. At this time, the protection coordination curve of the multi-circuit breaker is displayed through the auxiliary coordination curve output unit 54 so that the operator can easily check it. do.

The present invention has been described with reference to the embodiments shown in the drawings, but this is only exemplary, and those skilled in the art can make various modifications and equivalent other embodiments. will understand Therefore, the technical protection scope of the present invention should be determined by the claims below. Implementations described herein may also be embodied in, for example, a method or process, an apparatus, a software program, a data stream, or a signal. Even if discussed only in the context of a single form of implementation (eg, discussed only as a method), the implementation of features discussed may also be implemented in other forms (eg, an apparatus or program). The device may be implemented in suitable hardware, software and firmware. The method may be implemented in an apparatus such as a processor, which is generally referred to as a processing device including, for example, a computer, microprocessor, integrated circuit, programmable logic device, or the like. Processors also include communication devices such as computers, cell phones, personal digital assistants ("PDAs") and other devices that facilitate communication of information between end-users.

100: data input unit
200: data selection unit
300: optimization process unit
400: data result unit

Claims (5)

In the automatic calculation device for the multi-circuit breaker protection coordination set point of the underground distribution line for the configuration of RMU (Ring Main Unit),
a data input unit for receiving constraint conditions correlated with parameters of the multiple circuit breaker;
a data selector selecting a characteristic curve of the multiple circuit breaker for optimal protection coordination of the multiple circuit breaker;
an optimization processing unit calculating an optimal time-limited operation parameter and an optimal instantaneous operation parameter of the characteristic curve based on the constraint conditions, the characteristic curve, and a preset objective function; and
A data result unit outputting the optimal time-limited operation parameter and the optimal instantaneous operation parameter calculated by the optimization process unit; including,
The automatic calculation device for multi-circuit breaker protection coordination settings, characterized in that the constraint condition is set by Equation (1) below.

<Equation (1)>

Here, T _min is the minimum value of the magnetic limit operating time of the multi-circuit breaker, T _max is the maximum value of the magnetic limit operating time of the multi-circuit breaker, T _MWI is the operating time of the multi-circuit breaker, and TDS is the product of the time constant ( Time Dial Setting), TDS _min is the minimum value of the multi-circuit breaker magnetic limit time constant product, TDS _max is the maximum value of the multi-circuit breaker magnetic limit time constant product, TDS _MWI is the multi-circuit breaker time constant product, and T _{S /S CB} is the operating time characteristic of the circuit breaker at the substation, T _STP is the operating time characteristic of the switch-type protection device inside the ground transformer, T _FUSE is the operating time characteristic of the current limiting fuse inside the ground transformer, and T _Tr.Inrush is the inrush of the ground transformer It is the operation time characteristic according to the current, and CTI is the cycle time interval between the multi-circuit breaker and backup device
The method according to claim 1, wherein the constraints,
The operating time of the multiple circuit breaker, the time constant product of the multiple circuit breaker, the operating time characteristics of the substation side breaker, the operating time characteristics of the switch-type protection device inside the ground transformer, the operating time characteristics of the current limiting fuse inside the ground transformer, and the inrush current of the ground transformer An automatic calculation device for a multi-circuit breaker protection coordination set point, characterized in that it is a constraint condition related to at least one of the operating time characteristics according to.
delete The method of claim 1,
The optimal time-limited operation parameter and the optimal instantaneous operation parameter are the time-limited operation parameter and the instantaneous operation parameter when the objective function is maximized, respectively.
The method of claim 4,
The objective function is an automatic calculation device for multi-circuit breaker protection coordination settings, characterized in that defined by the following formula (2).

<Equation (2)>

Here, T _const is the high-current opening operating time of the multi-circuit breaker, that is, the time required due to the physical minimum response characteristics of the multi-circuit breaker, T _delay is the operating delay time of the multi-circuit breaker, and curve is IEC, KEPCO, ANSI, etc. is the multi circuit breaker TC operating curve, α, β, γ and L are the internal parameters of the multi circuit breaker characteristic curve, specifically α, β and L are the relay characteristic values, β is the characteristic curve index, and CT ratio is the instrument and the ratio of the rated primary current and the rated secondary current of the current transformer used for the relay, which is set as the current ratio of the multi-circuit breaker installation location, PS _MWI is the current setting value of the secondary side of the multi-circuit breaker, and I _fault is Fault current, I _pickup is the set value of the operating current of the multi-circuit breaker, and means the primary conversion value through the product of the secondary current (PS _MWI ) of the multi-circuit breaker installation location and the current transformer ratio, and I _pickup1 is the multi-circuit breaker's Instantaneous operation current correction value, I _pickup2 is the instantaneous operation current correction value of multi-circuit breaker

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