KR100288156B1 - Apparatus for preventing failure spread in power system - Google Patents

Abstract

PURPOSE: An apparatus is provided to achieve an improved stabilization efficiency by perceiving occurrence of failure in a rapid and accurate manner, while reducing the number of generator breakers. CONSTITUTION: An apparatus comprises a base station(100), a first branch station(200) and a second branch station(300). The first and second branch stations include data acquisition units(211,311), arithmetic operation units(212,312) for data processing, communication units(213,313) and control units(214,314) for controlling operation of circuit breakers. The control unit of the first branch station is configuration in such a manner that the switching control is performed by using self-acquired data when control data is not input from the base station. The base station includes a data acquisition unit(111); an arithmetic operation unit(112) for performing a stabilization algorithm and making judgment in accordance with the result of operation performed in a predetermined logic; a communication unit(113) for receiving information from branch stations and transmitting control data to the branch stations; and a display unit(114) for displaying the control state.

Description

Power system accident spread prevention device

The present invention relates to a device for acquiring several power generation and substation system data in a specific area system, recognizing an accident, grasping a current situation, and taking measures to suppress the spread of the accident. And it relates to a power system accident spreading prevention device for circuit breaker control.

In the current power system, due to the difficulty in securing a location, the power plant has a large area and a large capacity, and accordingly, a power line related to power plants is also composed of a large capacity line. In addition, power system operation is caused by transmission line failure in such a system due to the increase of the fault capacity due to the enlargement of the system and the multiple linkage operation. If so, there was a huge problem that led to generator outages and large regional outages.

In general, if a main transmission line breakdown occurs in the power system to which the large generator group belongs, this causes the power system to become unstable and the generator of the system synchronously breaks out, causing a large power outage. In this power system, the main station or local station of the power system accident spreading prevention device is installed in the main power station, and the system data is acquired and collected to select the minimum number of generators that can stabilize the system within 250mS in case of a transmission line accident. Control of one of the switching or grid switching and the power limitation is executed to prevent synchronous outage of the generators in the relevant system to prevent large power outages and damage to power facilities.

According to the conventional accident spread prevention device, the acquired data is the protection relay operation information, the breaker state (on / off), the amount of generation, the transmission line current and the failure recognition of the transmission line is based on this.

Final determination of the fault can be confirmed after the termination of the transmission line breaker. It takes 100mS (protection relay operation time 50mS + breaker operation time 50mS) from breakdown to breaker trip check.The time required for data transmission and algorithm execution time 50mS, and control of breaker after stabilization algorithm is delayed in auxiliary relay in the control unit. 20mS breaker, 50mS breaker break time, 150mS breaker turn-on time. The total required time is 220mS and 320mS shut-off control from the occurrence of accident to completion of breaker control. It is possible to control the stabilization by blocking the generator in the conventional system, but the system switching by the breaker input is impossible due to excessive control time.

Accordingly, the present invention is to enable the stabilization control (system switching, power limitation) within 250mS by quickly and accurately recognizing a failure and reducing the delay time of the auxiliary relay in the control unit.

The object of the present invention, by adding two input elements (transmission line instantaneous current, breaker trip current detection) to determine the accident during the duration of the accident to reduce the time required for accident recognition by up to 50mS, coil type auxiliary relay of the control unit It can be reduced by 20mS by replacing with a power semiconductor switch element.

1 is an overall configuration diagram of a power system accident spread prevention system of the present invention.

2 is an operation timing diagram of a power system accident spread prevention system according to the present invention.

3 is an explanatory diagram showing a logic diagram of accident type classification according to the present invention;

4A and 4B are exemplified diagrams comparing elements of switch means in a control unit of the prior art and the present invention;

5 is a flow diagram of the mother station operation of the power system accident spread prevention system of the present invention.

Figure 6 is a flow chart of the operation of the station 1 of the power system accident spread prevention system of the present invention.

7 is a flowchart illustrating the operation of the station 2 of the power system accident spread prevention system of the present invention.

Figure 8 is a system diagram showing an example of the power system accident spreading prevention system according to the present invention.

<Description of the code | symbol about the principal part of drawing>

100: mother country 111: data acquisition unit of the mother country

112: calculation unit 113: communication unit

114: display unit 200,300: slave 1, slave 2

211, 311: Local data acquisition unit

212, 312: Computation unit of own station 213, 313: Communication unit of own station

214, 314: control unit of the country

Hereinafter, an embodiment of the accident spreading prevention apparatus of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a system configuration diagram of an accident propagation prevention apparatus according to the present invention. As shown in FIG. 1, a mother station 100, a station 1 200, and a station 2 300 are included.

The own station 1, 2 (200, 300) includes a data acquisition unit 211 and 311 for acquiring the system data of the own station, an operation unit 212 and 312 for processing data, and a communication unit 213 for transmitting and receiving data. ) 313, and the control unit 214 (314) for blocking / injecting the breaker (CB). In particular, the own station 1 (200) is configured to perform its own separate stabilization algorithm so as to perform the system switching control only with its own acquisition data.

The mother station 100 includes a data acquisition unit 111 for acquiring system data of the mother station, an arithmetic unit 112 for calculating the acquired data, a communication unit 113 for communicating with its own stations, and a mother station and a local station. It is composed of a display unit 114 for displaying the system status, and performs the stabilization algorithm based on the acquired data of the station 1, 2 (200) 300 and the mother station 100 itself, and the results of the station 1, 2 (200) (300). Acquired system data acquires transmission line current (power: 430mS time delay), transmission line current (no time delay), protection relay operation information, breaker trip current information, breaker state (on / off) information, In addition to the above data, the generator generation amount is acquired.

2 shows an operation timing diagram of the system protection system and the apparatus. If an accident occurs in the system, the line current is suddenly increased as shown in (a), and the protection relay operates as (c) 50mS after the accident due to the increase of the line current, and cuts off the breaker trip coil. Voltage (DC 125V 10A) is applied for 50mS as in (d).

The circuit breaker is cut off at 50mS as shown in (e), and the applied voltage is turned off at the same time as the breaker. Power from generators and transmission lines continues to be acquired even after the breaker is opened due to the delay response characteristic of the T / D (above 430mS). Since the transmission line current T / D eliminates the delay response, it drops to "0" at the same time as the breaker is opened. In addition, since there is no response delay, when the transmission line accident occurs, it appears in proportion to the instantaneous current value and can detect an accident sign.

The present invention enables the quick and accurate recognition of accidents by checking whether the breaker trips the power supply or not and the transmission line current T / D.

3 is a logic diagram of accident recognition according to the present invention.

Logic diagram A is determined as an accident at the time of 50mS of an accident when the protection relay is operated, the breaker trip voltage is applied, and the current variation of the transmission line is over a certain amount.

Logic diagram B is determined as an accident at 50mS when the protective relay is activated and the breaker trip voltage is applied.

Logic diagram C is judged as an accident when the breaker trip voltage is applied and the current variation of the transmission line is over a certain amount.

Logic diagram D is determined as an accident when the protective relay operates (based on the previous data) and the breaker is open.

The logic diagram E is judged to be an incorrect operation due to an accident or human error when the breaker is open and the current "0" (the previous data> "0").

The logic diagram F is judged to be an incorrect operation due to an accident or human error when the circuit breaker trip voltage is applied (last data) and current "0" (last data> "0").

Logical diagram G is determined as an accident when proportional to the current "0" (last data> "0") and the corresponding line decrease in other line current changes (when operated only at the opposite end (substations without accident prevention devices installed)).

Logical diagrams A, B, and C indicate that the fault is in the continuous state of breakdown and breaker breakdown, and the control is determined in case of an accident requiring control of system switching. Logical diagrams D, E, F, and G show that the bus switching control is When only the power supply limit which is not included is required, an accident or misoperation is confirmed and control is executed. In addition, logic diagram G is a logic diagram for detecting misoperation and accident at the opposing substation.

4 shows a control unit of a mark according to the present invention. Conventionally, the coil-type auxiliary relay (2) is used, which may cause a surge during delay operation and initial operation, which may affect the system. However, the delay time is 20mS by replacing it with the MOSFET 13, which is a power semiconductor switch element. In short, the breaker voltage can be applied to the breaker immediately and the surge generated at the beginning of operation is eliminated.

5 is a flowchart illustrating an accident propagation prevention control according to the present invention. First, as data acquisition steps (S1-S3), data acquisition is acquired at 0, 1.5 and 3 mS time points. In the step (S4) of summing the acquired data to obtain an average value, the analog input value obtains an average value after sum of three acquisition values, and the digital state information applies two or more states of three times as final state data.

The mother station 100 receives and collects the mother station data and the station 1, 2 (200) and 300 data (S5), and checks the state change (S6) to confirm the presence of an accident.

When an accident occurs with a state change, the accident type is classified (S7) to control according to the accident. The accident type classification S7 acquires respective system data by the logic diagrams A to G as shown in FIG. 3 and classifies the accidents according to the logic result.

In case of an accident (S8), if a control action is applied (S8), an appropriate control action (S9) is transmitted to shut down the generator from the home station.If the control action is not applicable, the system configuration state correction and stabilization method is re-determined (S10). Release. In case of steady state, the stabilization method is decided based on the data. When the transmission line or the accident line is in operation, the breaker is in the ON state (S12), and when the current of the transmission line is above a certain value (i> 0 & i <k (accident current)) (S13), Re-determine the system configuration correction and stabilization (S14). In addition, if there is no accident (S15) by determining whether there is an accident, a stabilization method for an assumed accident is determined (S16), and the determined stabilization methods are stored as data (S11).

Fig. 6 is a control flowchart of station 1, in which data is acquired three times (S101-S103), analog is processed three times, and digital is data processed two or more times (S104). do. The processed data is transmitted to the mother station 100 (S105), and two transmission lines connected to the mother station 100 are cut off, and when the current i = 0 and the amount of power generation> 0 (S106), the bus is switched ( In other cases, it is determined whether the control command of the mother station 100 is received (S108), and when the control command is received, the control command is executed (S109).

If the primary data is collected and transmitted to the mother station, the bus switching is not necessary (S106), and control commands are not received from the mother station (S108), and data is acquired secondly again (S110-). S112), the data is processed (S113), and when the two transmission lines connected to the mother station are cut off and the current i = 0 and the power generation amount> 0 (S114), the bus switching (S115) is performed. The secondary data is not transmitted to the mother station. The primary data is acquired and sent to the mother station together with the control contents.

Fig. 7 is a control flowchart of station 2, which first acquires data three times (S201-S203), analog processes three times, and digital processes the data in two or more acquired states (S204). It transmits to the mother station 100 (S205). When the control command is received from the mother station 100 (S206), the command is executed (S207).

Therefore, the own station 1 (200) processes the data twice and transmits the data once to the mother station (100) and not twice to the mother station (100). In addition, the station 1 (200) dedicated stabilization algorithm operation is performed with the data. When the two lines of the transmission line connected to and connected to the mother station 100 are blocked, the circuit breaker of the station 1 200 is opened and then control of the grid switching is performed.

8 is a system to be applied to the accident spreading prevention apparatus of the present invention. Station 1 (200) is four generators are operating and is connected to the mother station 200 by a two-wire transmission line. In the own station 2 (200), four generators are in operation and connected to the mother country by a two-wire transmission line via a substation. The mother station 100 is connected to the main system through other substations besides 1 and 2 of its own station, and is connected to the 154 KV substation and other systems through the 345/154 KV transformer.

When an accident occurs on the main transmission line in the power system, the system must be stabilized only when the accident removal and stabilization control are accompanied. Although the existing stabilization device was applied to this power system, only one limit of power could be implemented within 250mS, which is the end time of stabilization control during operation.However, two input elements were added and proper logic was implemented for quick accident determination. The accident determination time was reduced by 50mS, and the time required by the controller was reduced by 20mS to enable the system switching control.

In this power system, the stabilization efficiency is the best when the control by the system switching is performed in parallel, and the number of generator breakers can be reduced to the minimum. In addition, it increases the stability of the system in proportion to the control speed during stabilization control by power limitation.

Claims (7)

A mother station 100, a station 1 (200), a station 2 (300), and the station 1, 2 (200) 300 are data acquisition units (211) (311) for acquiring system data of the own station. And a calculation unit 212 and 312 for processing data, a communication unit 213 and 313 for transmitting and receiving data to and from the mother station, and a control unit 214 and 314 for blocking / inserting the breaker CB. The control unit 214 of the own station 1 200 is configured to perform system switching control only with its own acquisition data when there is no control data from the mother station, and the mother station 100 acquires the system data of the mother station. Acquisition unit 111, a calculation unit 112 for performing a stabilization algorithm according to the acquired data, the operation unit 112 for calculating the accident by calculating according to a predetermined logic diagram for the accident determination, and receiving information from the marks Displaying the communication unit 113 and the control state for transmitting the control data according to the determination to the local station One display unit 114 is configured to perform a stabilization algorithm based on the acquired data of the two stations and the mother station itself, and transmit the result to the station. The mother station 100, the station 1 200, and the station. The system data acquired by 2 (300) includes transmission line currents (power: 430 mS or more time delay), transmission line current (no time delay), protective relay operation information, breaker trip current information, and breaker status (on / off). The system is configured to acquire information, and to determine the accident immediately after the protective relay operation by acquiring the generator generation amount in addition to the data. According to claim 1, the accident determination logic performed by the calculating unit of the mother station 100, Logic diagram A is determined as an accident at the time of 50mS of an accident when the protection relay is operated, the breaker trip voltage is applied, and the current variation of the transmission line is over a certain amount. Logic diagram B is determined as an accident at 50mS when the protective relay is activated and the breaker trip voltage is applied. Logic diagram C is judged as an accident when the breaker trip voltage is applied and the current variation of the transmission line is over a certain amount. Logic diagram D is determined as an accident when the protective relay operates (based on the previous data) and the breaker is open. The logic diagram E is judged to be an incorrect operation due to an accident or human error when the breaker is open and the current "0" (the previous data> "0"). The logic diagram F is judged to be an incorrect operation due to an accident or human error when the circuit breaker trip voltage is applied (last data) and current "0" (last data> "0"). Logical diagram G is determined as an accident when proportional to the current "0" (last data> "0") and the corresponding line decrease in other line current changes (when operated only at the opposite end (substations without accident prevention devices installed)). Among the seven logic diagrams, the logic diagrams A, B, and C are determined to be faults in case of an accident requiring control of system switching in the state of accident continuity and breaker interruption, and control is executed. G is determined to be an accident or a misoperation accident when only a power supply limit that does not include bus switching control is executed, and the control is performed. The logic diagram G is configured to detect misoperation and accident at the opposite substation. 7 accident decision logics based on A to G, fast judgment of accidents, monitoring of line breaks due to misoperation, and monitoring of misoperation and line accidents at substations without data acquisition devices. system. The power control system of claim 1, wherein the control unit of the station 1 and the station 2 uses the power semiconductor switch element as a switch means for bus switching and power cut-off control in order to eliminate surge generated at the initial stage of operation and improve speed. System Accident Ripple Prevention System. Acquisition of the system data of the mother country and the own country by the mother country and the own country 1 and the own country 2, transfer the system data acquired from the home country to the mother country to calculate the data collected from the home country through the algorithm to make an accident judgment and determine the accident In the power system accident propagation prevention method which transmits data to the local station to control the breaker, the system data is acquired three times at 1.5mS interval for each period, and the instantaneous current and breaker trip current are detected. Acquiring system data (S1-S3), and the analog input value obtains the average value after sum of three acquisition values, and digital state information is processed by applying two or more times of three times as the final state data. In step S5, the local station transmits the processed data to the mother station, and the mother station transfers the acquired system data of the mother station and station 1 and 2 to the mother station. Receiving and collecting the data (S5), checking the state change of the collected data in the home country (S6), and classifying the accident type according to a predetermined logic diagram (S7), and the accident type is controlled. (S8), the control command transmission step (S9) for transmitting the control command to the own station 1 and the own station 2 to take the corresponding action in the own station 1 and the own station 2, and the accident type does not correspond to the control action or control. After the command is transmitted, the system configuration state correction and stabilization method is re-determined (S10), and the data is stored (S11), and the state transmission line or the accident line which is in a normal state is re-injected in the state change determination (S6). When the breaker is in the ON state (S12) and the transmission line current i is above a certain value (i> 0 & i <k (accident current)) (S13), the system configuration is corrected and stabilized. Determining whether there is an accident after the step (S14) and the step (S14) (S15) if it is not an accident to determine the stabilization plan for the assumed accident (S16), and the step of storing the data of the results of the step (S14) and the step (S16) (S11) Power system accident ripple prevention control method. The method of claim 4, wherein the station 1 acquires data three times at regular intervals (S101-S103), and analog processes three times an average and digital processes the data in two or more acquisition states. (S104) and the processed data is transmitted to the mother station (S105), and when the state of the two lines connected to the mother station 100 is the breaker off, the current i = 0, and the power generation amount> 0 (S106), In the case of switching (S107) and if the condition of the step S106 is not satisfied, it is determined whether a control command of the home station is received (S108), and when the control command is received, the step of executing the control command (S109); If the control command is not received in step S108, the second step of acquiring data (S110 to S112) and processing the data again three times (S113), and the state of the two lines connected to the mother station is switched off and the current i = 0, power generation quantity> 0 (S114), without sending data to the mother station Power system accident prevention method ripple control, characterized in that configured to perform the step of ring (S115). The method of claim 4, wherein the slave station 2 acquires data three times at predetermined intervals (S201 to S203), and processes the data in an average state three times for digital and two or more times for digital acquisition (S204). And transmitting the processed data to the mother station 100 (S205), and when a control command is received from the mother station 100 (S206), executing the command (S207). Power system accident ripple prevention control method. The method of claim 4, wherein the classifying the accident form according to the predetermined logic diagram (S7), Logic diagram A is determined as an accident at the time of 50mS of an accident when the protection relay is operated, the breaker trip voltage is applied, and the current variation of the transmission line is over a certain amount. Logic diagram B is determined as an accident at 50mS when the protective relay is activated and the breaker trip voltage is applied. Logic diagram C is judged as an accident when the breaker trip voltage is applied and the current variation of the transmission line is over a certain amount. Logic diagram D is determined as an accident when the protective relay operates (based on the previous data) and the breaker is open. The logic diagram E is judged to be an incorrect operation due to an accident or human error when the breaker is open and the current "0" (the previous data> "0"). The logic diagram F is judged to be an incorrect operation due to an accident or human error when the circuit breaker trip voltage is applied (last data) and current "0" (last data> "0"). Logical diagram G is determined as an accident when proportional to the current "0" (last data> "0") and the corresponding line decrease in other line current changes (when operated only at the opposite end (substations without accident prevention devices installed)). Of the seven logic diagrams, The logic diagrams A, B, and C are determined to be faults in case of an accident requiring control of system switching in the state of accident continuity and breaker breaking, and control is executed. The logic diagrams A, B, and C are determined to be faults in case of an accident requiring control of system switching in the state of accident continuity and breaker breaking, and control is executed. The logic diagrams D, E, F, and G are determined to be an accident or a misoperation accident when only a power supply limit that does not include bus switching control is executed and control is executed. The logic diagram G is configured to detect misoperation and accidents at the opposite substation, and the seven accident decision logics according to the logic diagrams A to G are used to quickly determine an accident, to monitor the line cutoff due to the misoperation, and to obtain a data Power system accident spreading prevention control method characterized by monitoring the misoperation and track accident in the unstation.

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