JP6790002B2 - Transformer protection relay device - Google Patents

Description

An embodiment of the present invention relates to a transformer protection relay device.

The transformer protection relay uses a transformer protection current differential relay to detect an accident in the transformer. The current differential relay for transformer protection is, for example, a set of a primary side winding and a secondary side winding of the phase to be detected according to the winding configuration of the primary side and the secondary side of the transformer. The phase and magnitude of the current of each phase are matched, and the difference current Id of that phase is calculated. When an accident occurs in the phase to be detected, a difference current Id is generated, and the transformer protection current differential relay operates by detecting the occurrence of the difference current Id. Information on the phase in which such a transformer protection current differential relay operates (referred to as an operating phase) may not be sufficient information for determining the accident phase in which an accident has occurred.

JP-A-2002-186169

An object to be solved by the present invention is to provide a transformer protection relay device capable of determining an accident phase in which an accident has occurred.

The transformer protection relay device of the embodiment has an acquisition unit and a calculation unit. The acquisition unit acquires the electric energy related to the electric energy of the transformer formed by the winding configuration of a predetermined order. The calculation unit calculates at least the difference current related to the phase current on the primary side of the transformer and the phase current on the secondary side of the transformer from the acquired amount of electricity according to the information regarding the predetermined winding configuration. The operating status of the current differential relay of the transformer is determined, and based on the operating phase information of the operating current differential relay and the maximum difference current phase information regarding the phase in which the calculated difference current value exceeds a predetermined value. Then, the operating phase identified as operating reliably by the current differential relay is extracted to calculate the quantity of the operating phase, and at least the quantity of the operating phase and the current of each phase for each winding of the transformer are calculated. Based on the phase current maximum phase information regarding the phase whose value exceeds a predetermined value and the information on the connection type of the winding, the accident phase of the system accident related to the transformer is determined.

The figure which shows the structure of the transformer protection relay device 1 of 1st Embodiment. The figure which shows the structural example of the transformer 2 which includes the primary side winding and the secondary side winding of embodiment. The figure which shows the structural example of the transformer 2 which includes the primary side winding and the secondary side winding of embodiment. The figure which shows the structural example of the arithmetic unit 32 which concerns on embodiment. The flowchart which shows the procedure of the determination processing of embodiment. The figure which shows the structural example of the current differential relay operation phase determination part 323 which concerns on embodiment. The flowchart which shows the more specific processing procedure of step S41 of FIG. The flowchart which shows the more specific processing procedure of step S42 of FIG. The figure which shows the structure of the transformer protection relay system 1A of the 2nd Embodiment. It is a figure which shows the configuration example of the transformer 2A which comprises the primary side winding, the secondary side winding and the tertiary side winding of embodiment. The flowchart which shows the procedure of the determination processing of embodiment.

Hereinafter, the transformer protection relay device of the embodiment will be described with reference to the drawings. In the following description, the same reference numerals are given to configurations having the same or similar functions. Then, the duplicate description of those configurations may be omitted.

The transformer protection relay system shown in the embodiment includes a transformer protection relay device. The "difference current" referred to in the present application compares the magnitude of the phase current of a specific phase on the primary side of the transformer with the magnitude of the phase current of the phase of the secondary side of the transformer corresponding to that phase. It is an index showing the result. For example, the difference current was obtained by comparing the phase currents from the phase currents detected on the primary and secondary sides of the transformer, based on the result of a predetermined matching operation based on the turns ratio and the phase difference. It is a thing. Further, the "current differential relay operating phase information" is information indicating the phase (operating phase) in which the current operating relay provided in the transformer responds due to an accident in the transformer or the like. Further, the "difference current maximum phase information" is information on a phase in which the value of the difference current is equal to or more than a predetermined value among the values of the difference current of each phase of the transformer. The predetermined value may be determined based on the value of the difference current of the phase in which the difference current is the maximum. The calculation method will be described later.

(First Embodiment)
FIG. 1 is a diagram showing a configuration of a transformer protection relay system 1 of the embodiment.
The transformer protection relay system 1 includes a transformer 2, a transformer protection relay device 3, current transformers 111 to 113, and current transformers 121 to 123.

The transformer 2 includes a primary winding and a secondary winding that are insulated from each other, and the specifications of the primary winding and the secondary winding are both three-phase AC specifications. Current transformers 111 to 113 are installed on the primary side line of the transformer 2, and current transformers 121 to 123 are installed on the secondary side line. Each current transformer generates at least a phase current flowing through the primary side line of the transformer 2 and a phase current flowing through the secondary side line from the electric energy related to the electric energy of the transformer 2. The position on the line where each of the above current transformers is installed may be appropriately determined. Instead of the transformer, the amount of electricity related to the electric energy of the transformer 2 is detected, and at least the phase current flowing through the primary side line of the transformer 2 and the phase flowing through the secondary side line from the electric energy Those that generate current may be used.

In the transformer 2 shown in FIG. 1, the connection of the primary side winding is a neutral point grounded type Y connection (star connection), and the connection of the secondary side winding is a non-grounded type Δ connection (delta connection). ). Such a configuration of the transformer 2 is referred to as a "Yd1 configuration" (FIG. 2). The connection of the transformer 2 is an example, and is not limited to this.

The currents of the windings on the primary side of the transformer 2 are I1a', I1b', and I1c'. Assuming that the currents flowing through the lines connected to the primary side are I1a, I1b, and I1c in association with the phases a to c, the currents flowing through each line and the currents of each winding coincide with each other. The current transformers 111 to 113 output current information i1a, i1b, and i1c corresponding to these currents I1a, I1b, and I1c, respectively.

The currents of the windings on the secondary side of the transformer 2 are I2a', I2b', and I2c'. Assuming that the currents flowing through the line connected to the secondary side correspond to the phases a to c and are I2a, I2b, and I2c, the currents are (I2a'-I2c'), (I2b'-I2a'), respectively. (I2c'-I2b'). The current transformers 121 to 123 output current information i2a, i2b, and i2c corresponding to these currents I2a, I2b, and I2c, respectively.

The reference direction of each current is indicated by the direction of each arrow.

2 and 3 are diagrams showing a configuration example of a transformer including a primary winding and a secondary winding according to the embodiment. The transformers having the configurations shown in FIGS. 2 and 3 can be applied to the present embodiment. In the tables shown in FIGS. 2 and 3, a list of the transformer winding configuration and the calculation formula for calculating the phase current is described in relation to each other.

Information for identifying the configuration of the transformer 2 is described in the transformer winding configuration in this table, and the description is based on IEC (International Electrotechnical Commission) 60076-1. For example, in the case of the "Yy0 configuration" shown at the top of the table shown in FIG. 2, both the primary winding and the secondary winding are Y-connected. The arrow attached to the "Y" type symbol indicates the direction of the reference phase angle. In this case, the phase angles of the primary side and the secondary side are the same.

Further, as an arithmetic expression for calculating the phase current in the case of the "Yy0 configuration", i11, i12, i13, i21, i22, i23 indicating the current of each phase are shown in the column corresponding to the "Yy0 configuration" in FIG. Six equations indicating each of the above are described. In these equations, i1a, i1b, and i1c are current information (current value) of the windings related to each phase on the primary side. Further, i2a, i2b, and i2c are current information (current value) of the windings related to each phase on the secondary side.

From FIG. 2 to FIG. 3, similarly, "Dd0 configuration", "Yd1 configuration", "Dy1 configuration", "Dd2 configuration", "Dd4 configuration", "Yd5 configuration", "Dy5 configuration", "Dy5 configuration", " "Yy6 configuration", "Dd6 configuration", "Yd7 configuration", "Dy7 configuration", "Dd8 configuration", "Yd9 configuration", "Dd10 configuration", "Yd11 configuration", and "Dy11 configuration" are described in order. .. It should be noted that these configurations are defined in IEC60063-1 as including a primary winding and a secondary winding. As described above, some transformers 2 have different configurations, and are classified into a plurality of types. In each configuration, the winding connection is either or both of a three-phase Y connection and a Δ connection. The phases of the primary side and the secondary side are different depending on each configuration.

As described above, the "Yd1 configuration" is included in the third row from the top of the table in FIG. Hereinafter, the case of the “Yd1 configuration” will be described.

Returning to FIG. 1, the transformer protection relay device 3 will be described. The transformer protection relay device 3 includes an input unit 31, a calculation unit 32, and a display information generation unit 33. The input unit 31 is an example of an acquisition unit.

The input unit 31 takes in the current information i1a, i1b, i1c of the primary side a to c phases output from the current transformers 111 to 113, and further, the secondary side a to 123 output from the current transformers 121 to 123. The c-phase current information i2a, i2b, i2c is taken in. For example, the input unit 31 generates discrete data from each of the captured current information by performing sampling and data conversion at predetermined time intervals. The input unit 31 supplies the discrete data to the calculation unit 32. In this way, the input unit 31 acquires the electric energy related to the electric energy of the transformer 2 formed by the winding configuration of a predetermined order.

The calculation unit 32 acquires the discrete data and performs various preset calculation processes including internal / external accident determination of the transformer 2. The calculation unit 32 supplies the calculation result to the display information generation unit 33 to generate display information for display to the outside. The display information generation unit 33 generates display information and causes, for example, the input / output device 320E to display the display information. The arithmetic processing of the arithmetic unit 32 includes an arithmetic operation of a difference current value for detecting an internal accident of the transformer 2. The formula for calculating the difference current value will be described later.

FIG. 4 is a diagram showing a configuration example of the calculation unit 32 according to the embodiment.

The arithmetic unit 32 includes, for example, a CPU 320A, a RAM (Random Access Memory) 320B, a non-volatile storage device 320C, a portable storage medium drive device 320D, an input / output device 320E, and a communication IF device 320F. The arithmetic unit 32 may include a processor of any form instead of the CPU 320A, or may omit a part of each component shown in FIG.

The CPU 320A will be described below by expanding the program stored in the non-volatile storage device 320C or the program stored in the portable storage medium mounted on the portable storage medium drive device 320D into the RAM 320B and executing the program. Perform various processes. The RAM 320B is used as a working area by the CPU 320A. The non-volatile storage device 320C is, for example, an HDD, a flash memory, a ROM (Read Only Memory), or the like. A portable storage medium such as a DVD (Digital Versatile Disc), a CD (Compact Disc), or an SD card is mounted on the portable storage medium drive device 320D. The input / output device 320E includes, for example, an operation detection unit and a display unit as a touch panel. The communication IF device 320F communicates the detection result and the like with an external device via a communication network or the like.

The calculation unit 32 and the display information generation unit 33 (FIG. 1) are realized, for example, by the CPU 320A executing a program. Further, the calculation unit 32 and the display information generation unit 33 may be realized by hardware such as LSI (Large Scale Integration), ASIC (Application Specific Integrated Circuit), FPGA (Field-Programmable Gate Array), or software. It may be realized by the cooperation of hardware.

Returning to FIG. 1, the functional configuration of the calculation unit 32 according to the embodiment will be described.

The calculation unit 32 includes a flow ratio matching calculation unit 321, a phase matching calculation unit 322, a current differential relay operation phase determination unit 323, an accident phase determination calculation unit 324, and a storage unit 325.

In addition to the program, the storage unit 325 contains information on the calculation formula related to the flow ratio matching calculation, configuration information of the transformer 2, and information on the calculation formula of the current differential relay for detecting an internal accident of the transformer 2. , Accident phase flags F1, F2, F3 and other information are stored. The configuration information of the transformer 2 includes at least information on the connection type of the windings on the primary side and the secondary side.

The variable flow ratio matching calculation unit 321 performs a current change ratio matching calculation based on the current information of each phase taken in by the input unit 31 and the configuration information of the transformer 2, so that the current value based on the current change ratio can be calculated. Match so that there is no difference. The variable current ratio matching calculation unit 321 calculates the difference current in accordance with the variable current ratio matching calculation. The phase matching calculation unit 322 performs a phase matching calculation based on the current information of each phase taken in by the input unit 31 and the configuration information of the transformer 2.

Here, a method of calculating the difference current Id will be described. An example of a case where the α method is adopted in the calculation of the current differential relay applied to the transformer 2 will be illustrated. The target transformer 2 illustrated here has a Y-Δ connection shown in FIG. 1, and corresponds to the “Yd1 configuration” in FIG. The calculation formula of the difference current Id in that case is as follows.

In the above equations (1) to (3), K1 is the matching coefficient on the primary side of the transformer 2, and K2 is the matching coefficient on the secondary side of the transformer 2. As described above, the difference currents Id1, Id2, and Id3, which are the determination amounts of the current differential relay, are calculated by a calculation combining the phase currents i1a, i1b, i1c and i2a, i2b, i2c of each phase.

Here, the operating phase of the current differential relay when an accident is detected will be described. The relationship between the accident phase in the Y-Δ connection transformer 2 shown in FIG. 1 and the operating phase of the current differential relay determined based on the difference current is patterned for each location where the accident occurs. As shown in each pattern below, the operating phase of the current differential relay differs depending on the location of the accident.

First, a case where an accident occurs on the primary side (Y connection) of the transformer 2 will be described.
If the accident on the primary side is an A-phase accident, the current differential relays of each phase operate as follows.
Phase 1: Works reliably.
Second phase: Operates depending on the magnitude and phase of the accident current or the system accident detection sensitivity.
Third phase: Operates depending on the magnitude and phase of the accident current or the system accident detection sensitivity.

If the accident on the primary side is a B-phase accident, the current differential relays of each phase operate as follows.
1st phase: Operates depending on the magnitude and phase of the accident current or the system accident detection sensitivity.
Second phase: Works reliably.
Third phase: Operates depending on the magnitude and phase of the accident current or the system accident detection sensitivity.

If the accident on the primary side is a C-phase accident, the current differential relays of each phase operate as follows.
1st phase: Operates depending on the magnitude and phase of the accident current or the system accident detection sensitivity.
Second phase: Operates depending on the magnitude and phase of the accident current or the system accident detection sensitivity.
Third phase: Works reliably.

If the accident on the primary side is an AB phase accident, the current differential relays of each phase operate as follows.
Phase 1: Works reliably.
Second phase: Works reliably.
Third phase: Operates depending on the magnitude and phase of the accident current or the system accident detection sensitivity.

If the accident on the primary side is a BC phase accident, the current differential relays of each phase operate as follows.
1st phase: Operates depending on the magnitude and phase of the accident current or the system accident detection sensitivity.
Second phase: Works reliably.
Third phase: Works reliably.

If the accident on the primary side is a CA phase accident, the current differential relays of each phase operate as follows.
Phase 1: Works reliably.
Second phase: Operates depending on the magnitude and phase of the accident current or the system accident detection sensitivity.
Third phase: Works reliably.

If the accident on the primary side is a three-phase accident, the current differential relays of each phase operate together.

Next, a case where an accident occurs on the secondary side (Δ connection) of the transformer 2 will be described.
If the accident on the secondary side is a phase A accident, the current differential relays of each phase operate as follows.
Phase 1: Works reliably.
Second phase: Does not work.
Third phase: Works reliably.

If the accident on the secondary side is a B-phase accident, the current differential relays of each phase operate as follows.
Phase 1: Works reliably.
Second phase: Works reliably.
Third phase: Does not work.

If the accident on the secondary side is a C-phase accident, the current differential relays of each phase operate as follows.
Phase 1: Does not work.
Second phase: Works reliably.
Third phase: Works reliably.

If the accident on the secondary side is an AB phase accident, the current differential relay of each phase operates as follows.
Phase 1: Works reliably.
Second phase: Operates depending on the magnitude and phase of the accident current or the system accident detection sensitivity.
Third phase: Operates depending on the magnitude and phase of the accident current or the system accident detection sensitivity.

If the accident on the secondary side is a BC phase accident, the current differential relay of each phase operates as follows.
1st phase: Operates depending on the magnitude and phase of the accident current or the system accident detection sensitivity.
Second phase: Works reliably.
Third phase: Operates depending on the magnitude and phase of the accident current or the system accident detection sensitivity.

If the accident on the secondary side is a CA phase accident, the current differential relay of each phase operates as follows.
1st phase: Operates depending on the magnitude and phase of the accident current or the system accident detection sensitivity.
Second phase: Operates depending on the magnitude and phase of the accident current or the system accident detection sensitivity.
Third phase: Works reliably.

If the accident on the secondary side is a three-phase accident, the current differential relays of each phase will operate depending on the magnitude and phase of the accident current or the system accident detection sensitivity.

As described above, the accident phase in the transformer 2 and the operating phase of the current differential relay do not always match. The current differential relay applied to the transformer protection relay device 3 matches the current information according to the winding configuration of the transformer and performs the calculation. In order to determine the accident phase, the information on the operating phase specified by the calculation of the current differential relay is not sufficient. Therefore, it is difficult to determine the accident phase only from the information on the operating phase of the current differential relay.

Therefore, the current differential relay operating phase determination unit 323 and the accident phase determination calculation unit 324 identify the accident phase of the internal accident in the transformer 2 by combining the operating phase of the current differential relay with other information. For example, the accident phase determination calculation unit 324 obtains the maximum phase information of the current value of each phase output by the current transformer, in addition to the operating phase of the current differential relay determined by the current differential relay operating phase determination unit 323. Perform the arithmetic processing used for the judgment amount. This arithmetic processing compensates for the fact that the accident phase could not be determined by the determination processing based on the operating phase of the current differential relay.

Specifically, the transformer protection relay device 3 of the embodiment will be described with reference to FIGS. 1 and 5 to 8. FIG. 5 is a flowchart showing the procedure of the determination process of the embodiment.

The current differential relay applied to the transformer protection relay device 3 of the present embodiment matches the current information according to the winding configuration of the transformer 2 according to either the α method or the β method of the Clark coordinate method. Perform the calculation of. The following examples exemplify the case of the α method.

First, in step S10, the accident phase determination calculation unit 324 initializes the accident phase flags F1, F2, and F3. For example, the accident phase flags F1, F2, and F3 are provided so as to correspond to the A phase, the B phase, and the C phase of the transformer 2. Each accident phase flag holds a logical value indicating the soundness of each phase. For example, each accident phase flag indicates that it is an accident phase when it is set to "1". Prior to the following processing, for example, the accident phase determination calculation unit 324 initializes each accident phase flag to "0" indicating undetection.

Next, in step S20, the current differential relay operating phase determination unit 323 determines the operating phase and further calculates the number of operating phases. For example, the number of operating phases of a current differential relay can be summarized as follows for each connection / accident phase.

≪Case 1: In case of one-phase accident with Y connection winding≫
One phase of the current differential relay works reliably. The remaining two phases operate depending on the magnitude and phase of the accident current or the conditions of the accident detection sensitivity.
≪Case 2: In case of two-phase accident with Y connection winding≫
The two phases of the current differential relay work reliably. The remaining one phase operates depending on the magnitude and phase of the accident current or the condition of the accident detection sensitivity.

≪Case 3: In case of one-phase accident in winding of Δ connection≫
The two phases of the current differential relay work reliably. The remaining one phase does not work.
≪Case 4: In case of two-phase accident in winding of Δ connection≫
One phase of the current differential relay works reliably. The remaining two phases operate depending on the magnitude and phase of the accident current or the conditions of the accident detection sensitivity.

When the above accident occurs, the current differential relays related to the accident operate respectively. However, the operating phase of the current differential relay is a phase that operates reliably depending on the relationship between the winding configuration of the transformer 2 and the accident phase, and a phase that operates depending on the magnitude and phase of the accident current or the conditions of the system accident detection sensitivity. It is divided into. Therefore, the information on the operating phase of the current differential relay is not sufficient as a condition for determining the number of operating phases of the current differential relay. Therefore, in the embodiment, for example, the current differential relay operating phase determination unit 323 combines the information of the phase in which the current differential relay operates and the phase in which the value of the generated difference current is maximized to provide the current differential relay. Determine which phase is working reliably.

A process of determining the phase in which the current differential relay of the embodiment operates reliably will be described with reference to FIG. This process is performed by the current differential relay operating phase determination unit 323. FIG. 6 is a diagram showing a configuration example of the current differential relay operating phase determination unit 323 according to the embodiment. For example, the current differential relay operating phase determination unit 323 includes an operation determination unit 3231 of the current differential relay, a maximum phase determination unit 3232, a logical operation unit 3233, and a quantity calculation unit 3234. The operation determination unit 3231 includes each phase operation determination unit of 3231a, 3231b, and 3231c. The maximum phase determination unit 3232 includes each maximum phase determination unit 3232a, 3232b, and 3232c. The logical operation unit 3233 includes each unit of 3233a, 3233b, and 3233c. 3233a, 3233b, 3233c are AND circuits. The above AND circuit is an example of a logical operation circuit. The above AND circuit is an example and is not limited to this. For example, instead of this, an or circuit (logical operation circuit) that outputs a logical sum by inverting the logic of each signal is used. It can also be realized.

Each phase operation determination unit 3231a, 3231b, 3231c shows the operation determination result (operating phase information) of the current differential relay of the phase, and outputs "1" when the operation of the current differential relay is detected. The maximum phase determination units 3232a, 3232b, and 3232c show the determination result of the maximum phase of the value of the difference current generated by the accident, and when it is detected from the value of the difference current that the phase is the maximum phase, "1". Is output.

The maximum phase of the difference current value is defined as follows. For example, the phase that satisfies the following determination formula is the maximum phase.

Phase 1: Id1 ≧ Max (Id1, Id2, Id3) × Kd ・ ・ ・ (4)
Second phase: Id2 ≧ Max (Id1, Id2, Id3) × Kd ・ ・ ・ (5)
Third phase: Id3 ≧ Max (Id1, Id2, Id3) × Kd ・ ・ ・ (6)

According to the above equation (4), it is determined whether the difference current Id1 of the first phase is equal to or more than the value obtained by multiplying the maximum current value of the difference currents Id1, Id2 and Id3 of each phase by the constant Kd. The same applies to the second and third phases as shown in the formulas (5) and (6).

The phase to be determined as the phase in which the value of the difference current is maximized (maximum phase) is not necessarily limited to any one of the first phase, the second phase, and the third phase. Therefore, in the present embodiment, instead of narrowing down to only one phase, the phase having a relatively large difference current value is set as the maximum phase.

For example, in consideration of the fact that Id1, Id2, and Id3 have almost the same values in the case of a three-phase accident, a constant Kd (0 <Kd ≦ 1) defined as a predetermined real value is provided, and the value of the difference current is set. A phase in which a difference current of Kd times or more the value of the difference current of the largest phase is generated is also established as the maximum phase.

For example, the phase operation determination unit 3231a outputs the logic "1" when the "first phase" operates based on the operation determination of the current differential relay. For example, the logic "1" may be the H (high) level of the electrical signal. Further, the maximum phase determination unit 3232a outputs a logic "1" when the determination result of the maximum phase based on the difference current is the maximum phase of the first phase. In the AND circuit 3233a, the first input terminal is connected to the output terminal of the phase operation determination unit 3231a, and the second input terminal is connected to the output terminal of the maximum phase determination unit 3232a. When the AND circuit 3233a receives the logic "1" from both the phase operation determination unit 3231a and the maximum phase determination unit 3232a, the AND circuit 3233a outputs the logic "1".

Similarly, for the other phases, the AND circuit 3233b outputs the logic "1" when it receives the logic "1" from both the phase operation determination unit 3231b and the maximum phase determination unit 3232b. When the AND circuit 3233c receives the logic "1" from both the phase operation determination unit 3231c and the maximum phase determination unit 3232c, the AND circuit 3233c outputs the logic "1".

Each input terminal of the quantity calculation unit 3234 is connected to each output terminal of the above-mentioned AND circuit 3233a, 3233b, 3233c. The quantity calculation unit 3234 receives the respective outputs from the above-mentioned AND circuits 3233a, 3233b, and 3233c, and calculates the quantity of the AND circuits that output the logic "1".

Through the above logical operation processing, the current differential relay operating phase determination unit 323 determines the phase in which the current differential relay operates reliably, and obtains information on the number of operating phases.

Returning to FIG. 5, the description of the process is continued. The accident phase determination calculation unit 324 then determines the number of operating phases of the current differential relay that operates due to the occurrence of a transformer accident, based on the information on the operation of the current differential relay calculated in step S20 (step). S30). Thereby, it is possible to determine the number of operating phases of the current differential relay in which only the phases that operate reliably are counted.

From the determination result of the quantity of the operating phase of the current differential relay in step S30, when the quantity of the operating phase is only one, the accident phase determination calculation unit 324 "one-phase accident in the winding of the Y connection". Alternatively, the accident aspect is classified into "two-phase accident in the winding of the Δ connection", and the process proceeds to step S41. In addition, when the number of operating phases is two, the accident phase determination calculation unit 324 states that "a two-phase accident in the winding of the Y connection" or "a one-phase accident in the winding of the Δ connection". Is divided, and the process proceeds to step S42. The processes of steps S41 and S42 include, for example, determination processing of the connection type of the primary winding by the accident phase determination calculation unit 324 (step S40). Details of the processes in steps S41 and S42 will be described later.

After finishing the process of step S40, the accident phase determination calculation unit 324 switches the determination target to the secondary winding and executes the process of step S50. Step S50 includes the processes of steps S51 and S52. The processes of steps S51 and S52 are the same as the processes of steps S41 and S42 described above for determining the primary winding. When the accident phase determination calculation unit 324 finishes the process of step S50, the process proceeds to step S80.

When the number of operating phases is 3, the accident phase determination calculation unit 324 determines that it is a three-phase accident that has occurred in each ABC phase, and sets the accident phase flags F1, F2, and F3 (step S70). ..

When the number of operating phases is 0, the accident phase determination calculation unit 324 determines that no accident has occurred and does not set the accident phase flags F1, F2, and F3.

The accident phase determination calculation unit 324 states the accident phase flags F1, F2, and F3 when the operating phase of the current differential relay is not detected in step S30 or after the processing of step S50 or step S70 is completed. Based on the above, the result of determination that an accident has occurred in the phase of the accident phase flag in which "1" is set is output (step S80), and the series of processes shown in the figure is completed. For example, the transformer protection relay device 3 provides information that can identify the accident phase of the system accident that occurred in the system of the transformer 2, which is the result of the above determination, by the display unit of the input / output device 320E or the like. Can be displayed on. From this display, information for identifying the accident phase can be obtained, and the analysis of the accident state can be promptly proceeded.

Next, an example of a more specific process of the above step S41 (S51) will be illustrated. FIG. 7 is a flowchart showing a more specific processing procedure of step S41 of FIG. The process shown here is performed in the mode in which the number of operating phases of the current differential relay is one (step S30).

First, the accident phase determination calculation unit 324 determines the connection type of the transformer winding. For example, the accident phase determination calculation unit 324 determines whether or not the connection type of the primary winding is Y connection (step S411). As for the information on the form of the connection used in this determination, the transformer protection relay device 3 has information on whether it is a Y connection or a Δ connection as the configuration information of the transformer 2 in order to determine the configuration of the transformer 2 to be protected. There is. Alternatively, the operator may set the connection information as a settling item, and the accident phase determination calculation unit 324 may use this information to determine whether the connection is Y or Δ.

When the connection type of the primary winding is Y connection, the accident phase determination calculation unit 324 determines whether the quantity of the maximum phase of the current value is one on the primary side of the transformer winding (step). S412). In the above case, the accident phase determination calculation unit 324 determines the detected one phase as the accident phase, and among the accident phase flags F1, F2, and F3, the phase accident related to the "transformer primary side current maximum phase". “1” is set in the phase flag (step S413). For example, the accident phase determination calculation unit 324 uses, for example, the maximum phase information of the current value of each phase for each winding to determine whether it is a one-phase accident or a two-phase accident, and formulates from the following equation (7). The phase in which (9) is established is defined as the accident phase.

≪Maximum phase judgment formula of current value of each phase of transformer primary winding≫
Phase A: i1a ≧ Max (i1a, i1b, i1c) × Kc ・ ・ ・ (7)
Phase B: i1b ≧ Max (i1a, i1b, i1c) × Kc ・ ・ ・ (8)
Phase C: i1c ≧ Max (i1a, i1b, i1c) × Kc ・ ・ ・ (9)

According to the above equation (7), it is determined whether the current i1a of the A phase is equal to or larger than the value obtained by multiplying the maximum current value of the currents i1a, i1b and i1c of each phase by the constant Kc. The same applies to the B phase and the C phase as shown in the formulas (8) and (9).

As for the determination of the current value of each phase, the determination process in consideration of the multi-phase accident is performed as in the case of the determination of the maximum phase of the difference current value described above. Here, a constant Kc (0 <Kc ≦ 1) is provided, and a phase in which a current value that is Kc times or more the current value of the phase having the largest phase current value is also established as the maximum current phase.

When the connection type of the primary winding is Δ connection, the accident phase determination calculation unit 324 determines whether the quantity of the maximum phase of the current value is two on the primary side of the transformer winding (step). S414). In the above case, the accident phase determination calculation unit 324 determines the detected two phases as the accident phase, and among the accident phase flags F1, F2, and F3, the phase accident related to the "transformer primary side current maximum phase". “1” is set in the phase flag (step S415).

Further, when the accident phase determination calculation unit 324 determines from the determination result in step S412 that the quantity of the maximum phase of the current value is not one, when the process of step S413 is completed, the current value is determined from the determination result in step S414. When it is determined that the quantity of the maximum phase of the above is not two, or when the process of step S415 is completed, the series of processes shown in the figure is completed.

When the above process is used for determining the secondary winding, the same determination as for the primary winding is performed to determine the accident phase. The maximum phase information of the current value of each phase on the secondary side of the transformer 2 is calculated by using the following equations (10) to (12) in the same manner as the determination on the primary side.

≪Maximum phase judgment formula of current value of each phase of transformer secondary winding≫
Phase A: i2a ≧ Max (i2a, i2b, i2c) × Kc ・ ・ ・ (10)
Phase B: i2b ≧ Max (i2a, i2b, i2c) × Kc ・ ・ ・ (11)
Phase C: i2c ≧ Max (i2a, i2b, i2c) × Kc ・ ・ ・ (12)

When the transformer 2 has a tertiary winding, the same determination method as the determination process for the secondary winding can be applied.

The accident phase determination calculation unit 324 performs the accident phase determination processing when the number of operating phases of the current differential relay is one by the above processing. This process can be performed on the primary side and the secondary side, respectively, and the phase in which the accident phase flag is set can be specified as the accident phase in each process.

Next, an example of a more specific process of the above step S42 (S52) will be illustrated. FIG. 8 is a flowchart showing a more specific processing procedure of step S42 of FIG. The processing shown here is performed when the number of operating phases of the current differential relay is two modes.

First, the accident phase determination calculation unit 324 determines the connection type of the transformer winding. For example, the accident phase determination calculation unit 324 determines whether or not the connection type of the primary winding is Y connection (step S421).

When the connection type of the primary winding is Y connection, the accident phase determination calculation unit 324 determines whether the quantity of the maximum phase of the current value is two on the primary side of the transformer winding (step). S422). In the above case, the accident phase determination calculation unit 324 determines the detected two phases as the accident phase, and among the accident phase flags F1, F2, and F3, the phase accident related to the "transformer primary side current maximum phase". The phase flag is set (step S423).

When the connection type of the primary winding is Δ connection, the accident phase determination calculation unit 324 determines whether the quantity of the maximum phase of the current value is one on the primary side of the transformer winding (step). S424). In the above case, the accident phase determination calculation unit 324 determines the detected one phase as the accident phase, and among the accident phase flags F1, F2, and F3, the phase accident related to the "transformer primary side current maximum phase". The phase flag is set (step S425).

Further, when the accident phase determination calculation unit 324 determines from the determination result in step S422 that the quantity of the maximum phase of the current value is not two, when the process of step S423 is completed, the current value is determined from the determination result in step S424. When it is determined that the quantity of the maximum phase of is not one, or when the process of step S425 is completed, the series of processes shown in the figure is completed.

The accident phase determination calculation unit 324 performs the accident phase determination process when there are two operating phases by the above process. The accident phase determination calculation unit 324 executes this processing on the primary side and the secondary side, respectively, and identifies the phase in which the accident phase flag is set as the accident phase in each processing.

According to the first embodiment described above, the transformer protection relay device 3 is at least the primary side of the transformer 2 from the amount of electricity related to the amount of electricity of the transformer formed by the winding configuration of a predetermined order. The difference current related to the phase current of the transformer 2 and the phase current of the secondary side is calculated according to the information regarding the predetermined winding configuration, and the operation of the current differential relay of the transformer 2 is determined, and the operating current differential relay Based on the operating phase information and the difference current maximum phase information for the phase in which the calculated difference current value exceeds a predetermined value, the number of operating phases identified as reliable operation of the current differential relay is calculated, and at least , The number of operating phases based on the operating phase information, the phase current maximum phase information regarding the phase in which the current value of each phase for each winding of the transformer 2 exceeds a predetermined value, and the information on the connection type of the windings. Based on this, by determining the accident phase of the system accident related to the transformer 2, the accident phase of the transformer 2 in which the accident has occurred can be determined. For example, the transformer protection relay device 3 adds three phases to the accident phase when the number of phases detected by the current differential relay is three. Further, when the number of phases detected by the current differential relay is two, the number of phases based on the maximum phase current phase information in the Y-connected winding is two, and the phase current is described in the Δ-connected winding. The phase with one phase according to the maximum phase information is added to the accident phase. Further, in the transformer protection relay device 3, when the number of detected phases is one, the number of phases according to the phase current maximum phase information is one in the Y-connection winding and the Δ connection winding. Add two phases to the accident phase according to the phase current maximum phase information on the wire. By carrying out the above processing, the transformer protection relay device 3 can identify the accident phase in the transformer 2 in which the accident has occurred, and can enhance the convenience during maintenance and operation.

In order to apply the transformer protection relay device 3 to a plurality of types of transformers, the winding configuration of the transformer 2 is a condition for determining the accident phase of the system accident that occurred in the system of the transformer 2. Use the information about. As a result, the transformer protection relay device 3 can be shared regardless of the type of the transformer 2.

(Second Embodiment)
The transformer protection relay device of the embodiment will be described with reference to FIGS. 9 to 11.

FIG. 9 is a diagram showing the configuration of the transformer protection relay system 1A of the embodiment. The transformer protection relay system 1A includes a transformer 2A, a transformer protection relay device 3A, current transformers 111 to 113, current transformers 121 to 123, and current transformers 131 to 133.

The transformer 2A includes a primary winding, a secondary winding, and a tertiary winding that are insulated from each other, and both the specifications of the primary winding, the secondary winding, and the tertiary winding are the same. It is a three-phase AC specification. Current transformers 111 to 113 are installed on the primary side line of the transformer 2A, current transformers 121 to 123 are installed on the secondary side line, and current transformers 131 to 133 are installed on the tertiary side line. Has been done.

In the transformer 2A shown in FIG. 9, the connection of the primary side winding is a neutral point grounding type Y connection, whereas the connection of the secondary side winding and the connection of the tertiary side winding are not. It is a grounded type Δ connection. Such a configuration of the transformer 2A is called a "Yd1d1 configuration" (FIG. 10). The connection of the transformer 2A is an example and is not limited thereto.

FIG. 10 is a diagram showing a configuration example of a transformer 2A including a primary winding, a secondary winding, and a tertiary winding according to the embodiment. The transformer having the configuration shown in FIG. 10 can be applied to this embodiment. In the table shown in FIG. 10, a list of the transformer winding configuration and the calculation formula for calculating the phase current is described in relation to each other.

Information for identifying the configuration of the transformer 2A is described in the transformer winding configuration, and the description is based on IEC6003-1. For example, in the case of the "Yd1d1 configuration" shown in the third stage from the top, the primary winding is Y-connected, and both the secondary winding and the tertiary winding are Δ-connected. The arrows attached to the "Y" type and "Δ" type symbols indicate the direction of the reference phase angle. In this case, the phase angles of the secondary side and the tertiary side are the same. With reference to the phase angle on the primary side, the phase angles on the secondary side and the tertiary side are delayed by 30 degrees.

Further, as an arithmetic expression for calculating the phase current in the case of the "Yd1d1 configuration", i11, i12, i13, i21, i22, i23 indicating the current of each phase are shown in the column corresponding to the "Yd1d1 configuration" in FIG. , I31, i32, i33, and nine equations are described. In these equations, i1a, i1b, and i1c are current values of windings related to each phase on the primary side. Further, i2a, i2b, and i2c are current values of windings related to each phase on the secondary side. Further, i3a, i3b, and i3c are current values of windings related to each phase on the tertiary side.

In the figure, in addition to the above "Yd1d1 configuration", "Yy0d1 configuration", "Yy0d11 configuration", "Yd11d11 configuration", "Dy11d0 configuration", "Dy1d0 configuration", "Dd0d0 configuration", and "Yy0y0 configuration" is described. It should be noted that these configurations are defined in IEC60063-1 as including a primary winding, a secondary winding, and a tertiary winding. Such transformers are classified into a plurality of types having different configurations. The transformer of each configuration has the winding connection of either or both of the Y connection and the Δ connection, and the phases of the primary side, the secondary side, and the tertiary side are also different depending on the configuration. ..

The transformer protection relay device 3A includes an input unit 31A, a calculation unit 32A, and a display information generation unit 33. For example, the calculation unit 32A is configured in the same manner as the calculation unit 32 (FIG. 4).

The input unit 31A takes in the current information (i1a, i1b, i1c) of the a to c phases on the primary side output from the current transformers 111 to 113, and further, the secondary side output from the current transformers 121 to 123. The current information of the a to c phases (i2a, i2b, i2c) and the current information of the tertiary side a to c phases (i3a, i3b, i3c) output from the current transformer 131 to 133 are taken in.

The calculation unit 32A includes a flow ratio matching calculation unit 321A, a phase matching calculation unit 322A, a current differential relay operating phase determination unit 323A, an accident phase determination calculation unit 324A, and a storage unit 325A. The variable flow ratio matching calculation unit 321A, the phase matching calculation unit 322A, the current differential relay operating phase determination unit 323A, the accident phase determination calculation unit 324A, and the storage unit 325A are shown in FIG. The calculation unit 321, the phase matching calculation unit 322, the current differential relay operating phase determination unit 323, the accident phase determination calculation unit 324, and the storage unit 325 correspond to each other. The calculation unit 32A determines the transformer 2A having the primary winding, the secondary winding, and the tertiary winding that are insulated from each other. That is, the calculation unit 32A acquires discrete data on the primary side, the secondary side, and the tertiary side from the input unit 31A, and performs various preset calculation processes including the internal / external accident determination of the transformer 2A. I do. The calculation unit 32A supplies the result of the calculation result to the display information generation unit 33 to generate display information for displaying to the outside. The display information generation unit 33 generates display information and causes, for example, the input / output device 320E to display the display information. The process related to the accident phase determination on the tertiary side of the calculation unit 32A is the same process as the process related to the accident phase determination on the secondary side described above.

Next, the transformer protection relay device 3A of the embodiment will be described with reference to FIG. FIG. 11 is a flowchart showing the procedure of the determination process of the embodiment.

The transformer protection relay device 3A performs the process from step S10 to step S40, and then performs the process in step S50. Step S50 includes the processes of steps S51 and S52. The processing of step S51 and step S52 is the same as the processing of step S41 and step S42 described above.

The transformer protection relay device 3A performs the process of step S60 after the process of step S50. Step S60 includes the processes of steps S61 and S62. The processes of steps S61 and S62 are the same as the processes of steps S41 and S42 described above. When the accident phase determination calculation unit 324 finishes the process of step S60, the process proceeds to step S80.

The transformer protection relay device 3A determines based on the state of the accident phase flag when the operating phase of the current differential relay in step S30 is not detected, or after the processing of step S60 or step S70 is completed. (Step S80) is output, and the series of processes shown in the figure is completed. For the explanation of the processing of each step other than the above, the explanation of the flowchart shown in FIG. 5 is referred to.

According to the second embodiment described above, in addition to achieving the same effect as that of the first embodiment, the transformer protection relay device 3A protects the transformer 2A having a tertiary winding. be able to.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, as well as in the scope of the invention described in the claims and the equivalent scope thereof.

For example, a terminal device other than the transformer protection relay device 3 may receive the display information generated by the display information generation unit 33 from the transformer protection relay device 3 and display the display information.

1, 1A ... Transformer protection relay system, 2, 2A ... Transformer, 3, 3A ... Transformer protection relay device, 31, 31A ... Input unit (acquisition unit), 32, 32A ... Calculation unit, 33 ... Display Information generator, 111 to 113, 121 to 123, 131 to 133 ... Transformer, 321 ... Current transformer matching calculation unit, 322 ... Phase matching calculation unit, 323 ... Current differential relay operating phase determination unit, 324 ... Accident Phase determination calculation unit, 325 ... Storage unit

Claims (5)

An acquisition unit that acquires the amount of electricity related to the amount of electricity of a transformer formed with a winding configuration of a predetermined order, and an acquisition unit.
From the acquired amount of electricity, at least the difference current related to the phase current on the primary side of the transformer and the phase current on the secondary side of the transformer is calculated according to the information on the predetermined winding configuration, and the transformer Equipped with a calculation unit that determines the operating status of the current differential relay
The calculation unit
Based on the operating phase information of the operating current differential relay and the maximum difference current phase information regarding the phase in which the calculated difference current value exceeds a predetermined value, it is identified that the current differential relay operates reliably. Calculate the quantity of operating phase
At least, based on the quantity of the operating phase, the maximum phase current phase information regarding the phase in which the current value of each phase for each winding of the transformer exceeds a predetermined value, and the information of the connection type of the winding. A transformer protection relay device for determining the accident phase of a system accident related to the transformer. The calculation unit
Based on the quantity of the operating phase, the information on the winding configuration of the transformer, and the maximum phase current phase information, the accident phase of the system accident related to the transformer is determined.
The transformer protection relay device according to claim 1. The transformer protection relay device according to claim 1 or 2, further comprising a display information generation unit that generates information for displaying the accident phase of the system accident related to the transformer to the outside. The calculation unit
The difference current is calculated by using the α method or β method of the Clark coordinate method as the matching calculation method of the current differential relay.
The transformer protection relay device according to any one of claims 1 to 3. The transformer has a plurality of windings of the order, each of the windings of the order is formed of three phases, and the connection of the windings is either or both of Y connection and Δ connection.
The calculation unit
Performing a matching operation using the α method of the Clark coordinate method as the matching calculation method,
Using the result of the matching operation, a logical operation based on the operating phase information and the difference current maximum phase information is performed for each phase.
When the number of phases detected as satisfying a predetermined condition from the result of the logical operation is 3, it is determined that all the phases of the transformer are the accident phases.
When the number of detected phases is 2, the number of phases based on the phase current maximum phase information on the Y-connected winding is based on the phase current maximum phase information on the two phases and the Δ-connected winding. A phase having one phase is determined to be the accident phase, and the phase is determined to be the accident phase.
When the number of detected phases is one, the number of phases based on the phase current maximum phase information in the Y-connected winding is one, and the number of phases in the Δ-connected winding is based on the phase current maximum phase information. A phase having two phases is determined to be the accident phase.
The transformer protection relay device according to claim 4.

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