JP2008131788A - Transmission line protection relay system and device therewith - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transmission line protection relay system and a device therewith capable of reducing the cost and improving the transmission function. <P>SOLUTION: This transmission line protection relay system protects the transmission line by transmitting and receiving information on the protective relay devices through transmission paths. The protective relay devices installed on respective terminals of an electric power system interconnected among a plurality of terminals by the transmission line respectively perform protection computations for different protected targets. The devices transmit both the electric data necessary for the other protective relay device and the output information on the protection computation results performed in the own devices through a pair of transmission paths for connecting between the devices. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention transmits and receives the electrical quantity information of the own terminal and the opposite terminal via a pair of transmission lines connecting between the protective relay devices installed at each terminal of the power system in which a plurality of terminals are connected by a transmission line. The present invention relates to a transmission line protection relay system and apparatus for protecting a transmission line.

  As a power transmission line protection relay device in a power system, a current differential protection relay device that has a simple operation principle and can reliably determine an accident section at high speed is widely used.

  This current differential protection relay device is installed at each terminal of the transmission line to be protected, and the current data of each terminal is transmitted to each other via the transmission line, thereby receiving the current data of its own terminal. The differential calculation is performed using the current data of the opposite terminal, and the presence / absence of an accident in the transmission line is determined from the calculation result (for example, Non-Patent Document 1).

Further, since the current differential protection relay device performs data transmission by constructing a transmission path between the opposing devices as described above, the transmission line protection function described above is achieved by transmitting voltage data together with current data. In addition, it is possible to provide a step-out detection function that calculates the voltage phase difference between the self-terminal and the counter terminal and determines the presence or absence of step-out within the protection section from the calculation result (for example, Patent Document 1).
Yoshifumi Ohura “Protective Relay System Engineering” The Institute of Electrical Engineers of Japan 156-165 JP 2001-231155 A

  By the way, in the current differential protection relay device installed at each terminal of the transmission line, data transmitted through a pair of transmission lines connecting the devices has a transmission rate of 54 kbps and a transmission period electrical angle of 30 degrees (system frequency). Since data transmission is performed with the opposite end at 600 Hz in the case of 50 Hz and 720 Hz in the case of the system frequency 60 Hz), the amount of data that can be transmitted in one frame (one transmission cycle) is 90 bits in the case of 50 Hz and 75 in the case of 60 Hz. A bit.

  FIG. 8 is a diagram showing a transmission format in a conventional current differential protection relay device. As shown in FIG. 8, the conventional current differential protection relay device has a current data for three phases expressed in 12 bits and a fourth electric quantity that transmits 12 bits in 3 frames divided into 4 bits. Four amounts of electric quantity data of data (for example, zero phase current data and representative phase voltage data) are transmitted.

  Therefore, the conventional current differential protection relay device can only protect one transmission line with one device, and in order to protect two transmission lines, two currents per terminal. A differential protection relay device and two transmission lines are required.

  On the other hand, a current differential protection relay device having a transmission rate increased to 1.544 Mbps is also described in Non-Patent Document 1, and if this current differential protection relay device is used, two transmission lines can be provided. However, in this case, a 1.544 Mbps transmission line, which is more expensive than usual, is required.

  As described above, when the conventional current differential protection relay device protects two transmission lines, either install two devices by securing two 54 kbps transmission lines per terminal. It is necessary to secure a 544 Mbps transmission line and install one device for 1.544 Mbps. In either case, there is a first problem that the cost of the device including the transmission line becomes expensive.

  Further, when considering the protection of one transmission line, the conventional current differential relay device transmits the fourth electric quantity data divided into three frames, so that the data update cycle is long. There is a second problem that the high-speed operation cannot be expected in the protection function using the electric quantity data 4.

  Furthermore, when the electric quantity data is expressed by a larger number of bits, for example, 16 bits, for the purpose of improving accuracy, the conventional current differential relay device does not have a margin for allocating increasing bits to the transmission format, and has 12 bits. There is a third problem in that transmission must be cut off.

  The second and third problems can also be solved by applying a current differential relay device for a transmission speed of 1.544 Mbps. In this case, a 1.544 Mbps transmission line must be secured. However, as with the first problem, the cost of the apparatus including the transmission line becomes expensive.

  The present invention has been made to solve the above-described problems, and enables protection for two transmission lines while maintaining a transmission rate of 54 kbps. In the case of protection for one transmission line, bit division is performed. Transmission line protection relay system and apparatus capable of transmitting the fourth electric quantity data without transmission, enabling transmission of the electric quantity data exceeding 12 bits, and reducing the cost and improving the transmission function The purpose is to provide.

  In order to achieve the above object, the present invention constitutes a power transmission line protective relay system and its apparatus by the following means.

  The present invention is a power transmission line protection relay system that protects a power transmission line by transmitting and receiving information on a protective relay device provided on each terminal of a power system in which a plurality of terminals are connected by a power transmission line. The devices installed at the terminals are protection relay devices that perform protection calculations for different protection targets, and the electrical quantity data required by the partner protection relay devices by a pair of transmission lines connecting each device And output information of the result of the protection calculation performed by the own apparatus.

  The present invention relates to a power transmission line protection relay that protects a two-line power transmission line by transmitting / receiving information of a protective relay device provided at each terminal of a power system in which a plurality of terminals are connected by a two-line power transmission line via a transmission line. In the system, any one terminal is a protection relay device that performs a protection calculation of the first transmission line, and any one terminal different from this is a protection relay that performs a protection calculation of the second transmission line. A device is characterized in that, by means of a pair of transmission lines connecting between the devices, the electrical quantity data required by the partner protection relay device and the output information of the protection calculation result performed by the device itself are transmitted. .

  The present invention relates to a power transmission line protection relay system that protects a power transmission line by transmitting and receiving information on a protective relay device provided at each terminal of a power system in which a plurality of terminals are connected by a power transmission line. One of the terminals is a protective relay device that performs a protection operation for a short circuit accident on the transmission line, and one of the terminals different from this is a protection operation for either or both of a ground fault and a step-out detection of the transmission line. The protection relay device to be used, and transmitting the electrical quantity data required by the partner protection relay device and the output information of the protection calculation result performed by the own device through a pair of transmission lines connecting the devices It is characterized by.

  The present invention relates to a power transmission line protection relay system that protects a power transmission line by transmitting and receiving information on a protective relay device provided at each terminal of a power system in which a plurality of terminals are connected by a power transmission line. One of the terminals is a protective relay device that performs a protection operation using current data of two phases of the three phases of the transmission line, and one terminal different from this is the remaining one phase of the three phases of the transmission line A protection relay device that performs a protection calculation using current data, and the amount of electricity required by the partner protection relay device and a protection calculation result performed by the device itself through a pair of transmission lines connecting the devices. The electrical quantity data to be transmitted is expressed by a bit length exceeding 12 bits.

  The present invention is a digital current differential protection that is installed at each terminal of an electric power system in which a plurality of terminals are connected by a transmission line, and detects the occurrence of an accident within a protection section from current information of each terminal and performs a predetermined output. In the relay device, A / D conversion means for performing digital conversion by sampling the self quantity of electricity based on a sampling signal, and outputting the self information including the quantity data outputted from the A / D conversion means Transmitting means, receiving means for receiving data transmitted from the current differential protection relay device of the opposing terminal via the communication medium, and the electric quantity of the own terminal and the opposing terminal obtained from the transmitting means and the receiving means Control means for performing a protection operation from data, output means for performing a predetermined output according to the result of the operation means, and controlling the sampling signal at the same timing at each terminal. A sampling synchronization control means, wherein the computing means performs a protection computation for different protection targets in the opposing device, and the transmitting means is the opposing device and the electrical quantity data required by the counterpart device and the The predetermined data based on the calculation result of the calculation means is transmitted.

  The present invention is a digital current difference that is installed at each terminal of a power system in which a plurality of terminals are connected by a two-line transmission line, and detects the occurrence of an accident within a protection section from current information of each terminal and outputs a predetermined output. In the dynamic protection relay device, A / D conversion means for performing digital conversion by sampling the self quantity of electricity based on a sampling signal, and self-end information including quantity data output from the A / D conversion means Transmitting means for outputting data, receiving means for receiving data transmitted from the current differential protection relay device of the opposing terminal via the communication medium, and the own terminal and the opposing terminal obtained from the transmitting means and the receiving means Calculation means for performing protection calculation from the electric quantity data, output means for performing a predetermined output according to the result of the calculation means, and the sampling signal at the same timing at each terminal A sampling synchronization control means for controlling, and the computing means performs a protection computation for protection of transmission lines of different lines by an opposing device, and the transmitting means is an opposing device and requires a device at the other end. Electric quantity data of the line and predetermined data based on the calculation result of the calculation means are transmitted.

  The present invention is a digital current difference that is installed at each terminal of an electric power system in which a plurality of terminals are connected by a transmission line, and detects the occurrence of an accident within a protection section from current information of each terminal and outputs a predetermined output. In the dynamic protection relay device, A / D conversion means for performing digital conversion by sampling the self quantity of electricity based on a sampling signal, and self-end information including quantity data output from the A / D conversion means Transmitting means for outputting data, receiving means for receiving data transmitted from the current differential protection relay device of the opposing terminal via the communication medium, and the own terminal and the opposing terminal obtained from the transmitting means and the receiving means Calculation means for performing protection calculation from the electric quantity data, output means for performing a predetermined output according to the calculation result of the calculation means, and the sampling signal at the same timing at each terminal A sampling synchronization control means for controlling, and the arithmetic means performs a protection operation for different phases in the opposing device, and the transmission means is used for the electric quantity data of the phase used in the opposing device and the arithmetic result of the arithmetic means. The predetermined amount of data is transmitted, and the transmitted electric quantity data is represented by a bit length exceeding 12 bits.

  According to the present invention, it is possible to protect two transmission lines while maintaining a transmission rate of 54 kbps. In the case of protection for one transmission line, the fourth electric quantity data can be transmitted without dividing the bit. At the same time, it is possible to transmit electric quantity data exceeding 12 bits, and it is possible to reduce costs and improve the transmission function.

  Embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
FIG. 1 is a configuration diagram showing a first embodiment of a power line protection relay device according to the present invention.

  Note that the normal power system is a three-phase AC, but in FIG.

  In FIG. 1, reference numerals 1a and 1b denote two power transmission lines to be protected that are connected between the two buses A and B, and reference numeral 2 denotes a current transformer provided on each line of the power transmission lines 1a and 1b. (CT) 3 is a circuit breaker (CB) installed in each line of the power transmission lines 1a and 1b on the terminal side.

  On the other hand, 4a and 4b are installed corresponding to the terminals A and B, respectively, and a current differential protection relay device 5a to which current is input from the current transformer 2 provided in each line of the transmission line on each terminal side, 5a , 5b are transmission paths for connecting the current differential protection relay devices 4a, 4b on the respective terminal sides to transmit / receive current data.

  In the current differential protection relay device 4a, currents flowing through the respective lines are input from the current transformers 2 provided on the transmission lines 1a and 1b on the A terminal side, and these currents are converted into voltage signals of a predetermined magnitude. An input converter 6 for conversion, an analog filter 7 for removing a harmonic component that causes a folding error due to sampling of the voltage signal converted by the input converter 6, and a voltage signal sampled by the analog filter 7 for a predetermined sampling period The analog / digital conversion means 8 which performs sampling and digital conversion in the digital signal, and the digital data digitally converted by the analog / digital conversion means 8 are inputted, and the number of terminals set by the setting means 14 which will be described in detail later and the protection line ( In this example, based on the power transmission line 1b), the current data of the protection line at its own end and the pair transmitted to the opposite end Current data of the protection line at the end (in this example, the transmission line 1a) is selected, and current data of the protection line at the end (Ia, Ib, Ic on the transmission line 1b side) is transmitted from the device at the opposite end. Computation means 9 for performing differential computation with the incoming current data, opposing current data (Ia, Ib, Ic on the transmission line 1a side) of the protection line at the opposite end selected by the computation means 9 and the differential computation result Transmitting means 11 for transmitting to the device at the end, current data (Ia, Ib, Ic on the power transmission line 1b side) transmitted from the device at the opposite end, and differential operation result of the device at the opposite end are received and calculating means 9 To the protection line (1b) of the own end and the opposite end based on the differential operation result of the protection line at the own end from the receiving means 12 and the operation means 9 and the differential operation result of the device at the opposite end received by the receiving means 12 Open / close command to circuit breaker 3 of protection line (1a) And an output means 10 for force.

  In addition, the current differential protection relay device 4a has a sampling synchronization control means 13 for sampling the currents of the transmission lines 1a and 1b at the same timing as the devices at the opposite ends and performing the current differential calculation correctly by the calculation means 9. Is provided. The sampling synchronization control in the sampling synchronization control means 13 can be realized by a known sampling synchronization method described in, for example, Japanese Patent No. 1540325 implemented by a conventional current differential protection relay device. Then, the detailed description is abbreviate | omitted.

  The above is the configuration of the current differential protection relay device 4a on the A terminal side, but the current differential protection relay device 4b on the B terminal side has the same configuration as described above, and therefore the description and description thereof are omitted here.

  Next, the operation of the transmission line protection relay device configured as described above will be described.

  In the current differential protection relay devices 4a and 4b installed at the terminals A and B, which of the current data of the power transmission lines 1a and 1b is used by each device to perform the current differential calculation by the calculation means 9 or opposite Which current data is transmitted from the transmission means 11 to the end, and is output to the output means 10 according to the current differential calculation that can be realized by the calculation means 9 and the result, and the current differential calculation result is opposed to the transmission means 11. It is necessary to set correctly whether to transmit to the end.

  In order to realize this device setting, first, the number of terminals and the line to be protected are set from the settling means 14 to the calculation means 9.

  In the case of the present embodiment, the arithmetic means 9 of the current differential protection relay device 4a is set to “2 terminals” for the number of terminals and “2L (power transmission line 1b) protection” for the line to be protected, Of the current differential protection relay device 4b is set to “2 terminals” as the number of terminals and “1L (transmission line 1a) protection” as the line to be protected. The current differential protection relay devices 4a and 4b make the determination shown in the flowchart of FIG. 2 using the settling result, and determine the setting of the own device.

  That is, the current differential protection relay device 4a transmits to the output means 10 according to the current differential calculation that can be realized by the calculation means 9 and the result thereof, that the transmission means 11 transmits the current data of the transmission line 1a. In addition, it is determined that the output from the transmission means 11 to the opposite end is for the power transmission line 1b.

  Similarly, the current differential protection relay device 4b transmits the current data of the transmission line 1b from the transmission means 11 and outputs to the output means 10 according to the current differential calculation that can be realized by the calculation means 9 and the result. At the same time, it is determined that the output from the transmission means 11 to the opposite end is for the power transmission line 1a.

  When the current flowing through the power transmission lines 1a and 1b of the terminals where the current differential protection relay devices 4a and 4b are set as described above is introduced via the current transformer 2, the input conversion is performed. The analog signal is converted into a voltage signal of a predetermined size by the filter 6 and the analog filter 7 removes the harmonic components that are aliasing errors due to the sampling. Converted to data.

  Here, the current differential protection relay device 4 a installed at the terminal A is installed at the terminal B through the transmission line 5 with the current data of the transmission line 1 a converted from the transmission means 11 into digital data. It transmits to the current differential protection relay device 4b. The receiving means 12 of the current differential protection relay 4b installed at the terminal B receives the current data of the power transmission line 1a of the terminal A transmitted from the terminal A, and sends the current data to the own device. The introduced current data of the transmission line 1 a is passed to the calculation means 9.

  On the other hand, the current differential protection relay device 4b installed at the terminal B receives the current data of the transmission line 1b converted from the transmission means 11 into digital data via the transmission line 5 and the current installed at the terminal A. The data is transmitted to the differential protection relay device 4a. The receiving means 12 of the current differential protection relay 4a installed at the terminal A receives the current data of the power transmission line 1b of the terminal B transmitted from the terminal B, and sends this current data to the own device. The introduced current data of the transmission line 1b is passed to the calculation means 9.

  Thus, by transmitting the current data of the power transmission line 1a from the terminal A and the current data of the power transmission line 1b from the terminal B, the calculation means 9 of the current differential protection relay device 4a installed at the terminal A is obtained. Current data of the power transmission line 1b of the terminal A and the terminal B is collected, and the current data of the power transmission line 1a of the terminal A and the terminal B is stored in the calculation means 9 of the current differential protection relay device 4b installed in the terminal B. Gather.

  This means that the calculation means 9 of the current differential protection relay device 4a at the terminal A can realize a current differential calculation for the power transmission line 1b, and the calculation means 9 of the current differential protection relay device 4b at the terminal B has a power transmission line. This means that the current differential operation for 1a can be performed, and the transmission line required at that time is configured to transmit only one line of current data from either the power transmission line 1a or 1b. It can be seen that the transmission capacity is not increased, and only one transmission line of 54 kbps as in the conventional current differential protection relay device is required.

  On the other hand, in order to protect the transmission line, it is necessary to output a predetermined output from the output means 10 according to the result of the current differential calculation performed by the calculation means 9 and to control the circuit breaker 3 of each terminal according to the output. However, as described above, the current differential calculation for the transmission line 1a can be realized only on the terminal B side, and the current differential calculation for the transmission line 1b can be realized only on the terminal A side. The calculation means 9 transmits the same information as the output to the output means 10 from the transmission means 11 via the transmission path 5 as transmission data. As a result, an output that cannot be calculated by itself can be obtained, and protection for two transmission lines can be realized with only one current differential protection relay device per terminal.

  At this time, the output information to be additionally transmitted as transmission data is different from current data that must be expressed by 12 bits per quantity, and is ON or OFF for controlling the circuit breaker 3 from the output means 10 of the opposite terminal. Since the information may be sufficient, 1 bit can be secured in the minimum and 3 bits can be secured even when individual control for three phases is required, and this can be realized without changing the transmission rate.

  As described above, according to the first embodiment of the present invention, the current data of the power transmission line 1a is transmitted from the terminal A, and the current data of the power transmission line 1b is transmitted from the terminal B. The current data of the transmission line 1b is collected in the differential protection relay device 4a, and the current data of the transmission line 1a is collected in the current differential protection relay device 4b installed in the terminal B. In the current differential protection relay device 4a, the current differential calculation for the transmission line 1b can be realized, and in the current differential protection relay device 4b at the terminal B, the current differential calculation for the transmission line 1a can be performed. On the contrary, since the protection output information of the transmission line 1b is transmitted from the terminal A and the protection output information of the transmission line 1a is transmitted from the terminal B, the number of transmission lines between the devices and the transmission speed are not changed. It is possible to protect two transmission lines That.

(Second Embodiment)
FIG. 4 is a block diagram showing a second embodiment of the present invention. The same components as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  The difference between the present embodiment and FIG. 1 is a configuration in which only one line of the power transmission line 1a is protected, and the current differential protection relay devices 4a and 4b installed at the terminal A and the terminal B are connected. Current differential protection and step-out detection are performed by inputting a current flowing from the current transformer 2 to the power transmission line 1a and a voltage from the instrument transformer PT connected to the bus of each terminal.

  Further, in the current differential protection relay devices 4a and 4b, the calculation means 9 sets the calculation function of either the number of terminals and the current differential function or the step-out detection function by the settling means 14 and sets the calculation function 9 to its own end. 1 except that one of the current data or voltage data required for the calculation function and the other of the current data or voltage data required for the calculation function at the opposite end are selected.

  Next, the operation of the power line protection relay device configured as described above will be described.

  In the current differential protection relay devices 4a and 4b installed at the terminals A and B, the current differential calculation or step-out detection is performed by the calculation means 9 using either the current data or the voltage data of the transmission line 1a in each device. Output to the output means 10 according to whether current data or voltage data is transmitted from the transmission means 11 to the opposite end, a current differential calculation function or step-out detection function that can be realized by the calculation means 9, and the calculation result In addition, it is necessary to correctly set whether to transmit from the transmission means 11 to the opposite end.

  In order to realize this device setting, first, the setting means 14 sets the number of terminals and either the current differential function or the step-out detection function to the calculation means 9.

  In the case of this embodiment, the calculation means 9 of the current differential protection relay device 4a sets “2 terminals” as the number of terminals and sets the “step-out detection function” as the calculation function to be performed, The calculation means 9 of the differential protection relay device 4b sets “2 terminals” as the number of terminals and “current differential” as the calculation function to be performed. The current differential protection relay devices 4a and 4b make a determination using the settling result and determine the setting of the own device.

  In the current differential protection relay device 4a, it is the current data of the power transmission line 1a that is transmitted from the transmission means 11, and the calculation means 9 calculates and outputs to the output means 10 according to the result. It is determined that it is a step-out detection result that is output to the opposite end. Similarly, in the current differential protection relay device 4b, it is the voltage data that is transmitted from the transmission means 11, and the calculation means 9 calculates and outputs the result to the output means 10 according to the result. It is determined that it is the current differential calculation result that is output to the end.

  With the current differential protection relay devices 4a and 4b set in this way, the current flowing through the power transmission line 1a at the terminals where they are installed is introduced via the current transformer 2, and the power transmission line 1a When the voltage is introduced through the instrument transformer PT, these current and voltage are converted into a voltage signal of a predetermined magnitude by the input converter 6 and the analog filter 7 generates a harmonic error resulting from a sampling error. After the removal, sampling is performed at a predetermined cycle, and the analog / digital conversion means 8 converts it into digital data.

  Here, the current differential protection relay device 4 a installed at the terminal A is installed at the terminal B through the transmission line 5 with the current data of the transmission line 1 a converted from the transmission means 11 into digital data. It transmits to the current differential protection relay device 4b. The receiving means 12 of the current differential protection relay 4b installed at the terminal B receives the current data of the power transmission line 1a of the terminal A transmitted from the terminal A, and sends the current data to the own device. The introduced current data of the transmission line 1 a is passed to the calculation means 9.

  On the other hand, the current differential protection relay device 4b installed at the terminal B receives the voltage data of the transmission line 1a converted from the transmission means 11 into digital data via the transmission line 5 and the current installed at the terminal A. The data is transmitted to the differential protection relay device 4a. The receiving means 12 of the current differential protection relay 4a installed at the terminal A receives the voltage data of the power transmission line 1a of the terminal B transmitted from the terminal B, and receives this voltage data and the own device. The voltage data of the introduced power transmission line 1a is transferred to the calculation means 9.

  Thus, by transmitting the current data of the power transmission line 1a from the terminal A and the voltage data of the power transmission line 1a from the terminal B, the calculation means 9 of the current differential protection relay device 4a installed at the terminal A. Voltage data of the power transmission line 1a of the terminal A and the terminal B is collected, and the current data of the power transmission line 1a of the terminal A and the terminal B is stored in the calculation means 9 of the current differential protection relay device 4b installed in the terminal B. Gather.

  This means that the calculating means 9 of the current differential protection relay device 4a at the terminal A can realize a step-out detection function for the power transmission line 1a, and the calculation means 9 of the current differential protection relay device 4b at the terminal B is a power transmission line. This means that a current differential operation for 1a can be performed.

  Further, the step-out detection result calculated by the current differential protection relay device 4 a at the terminal A is output to the output means 10, and the current differential protection relay device 4 b at the terminal B from the transmission means 11 via the transmission line 5. The current differential calculation result calculated by the current differential protection relay device 4 b at the terminal B is output to the output means 10, and the current differential protection relay at the terminal A is transmitted from the transmission means 11 via the transmission line 5. It transmits to the electric apparatus 4a.

  As a result, an output on the side that cannot be calculated by itself can be obtained, and power transmission line protection and step-out detection by current differential calculation with respect to the power transmission line 1a with only one current differential protection relay device per terminal. A kind of protection can be realized.

  As described above, according to the second embodiment of the present invention, the step-out detection calculation is performed in the current differential protection relay device 4a installed in the terminal A, and the current differential protection relay installed in the terminal B. Since the current data of the power transmission line 1a is transmitted from the terminal A and the voltage data of the power transmission line 1a is transmitted from the terminal B so that the device 4b can perform the differential current calculation, the fourth electric quantity has been obtained so far. As a first electric quantity of transmission data in the direction from the terminal B to the terminal A, 12 bits can be directly transmitted in one frame.

  Accordingly, the fourth electric quantity data can be transmitted without being divided in the case of protection for one transmission line.

  Furthermore, in the present invention, since the fifth and sixth electric quantities can be transmitted from the terminal B to the terminal A, it is possible to improve the function. For example, in the conventional current differential protection relay device, the zero-phase current and voltage data that could only be transmitted as either the fourth electric quantity can be transmitted simultaneously and in one frame without being divided. Therefore, in addition to the above-described step-out detection function, it is possible to have a zero-phase current differential protection function.

(Third embodiment)
FIG. 5 is a block diagram showing a third embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

The difference between the present embodiment and FIG. 1 is a configuration in which only one line of the power transmission line 1a is protected, and the current differential protection relay devices 4a and 4b installed at the terminal A and the terminal B are connected. Currents I _A , I _B , and I _C flowing through the three phases of the transmission line 1a are input from the current transformer 2 to provide the _C differential protection function for the current differential protection relay device 4a, The current differential protection relay device 4b is provided with A-phase and B-phase protection functions.

  The current differential protection relay devices 4a and 4b are the same as those in FIG. 1 except that the number of terminals and the phase to be protected are selected by the setting means 14 for the calculation means 9.

  Next, the operation of the power line protection relay device configured as described above will be described.

  First, the number of terminals and the protective phase are set from the setting unit 14 to the calculation unit 9.

  In the case of the present embodiment, the arithmetic means 9 of the current differential protection relay device 4a sets “2 terminals” as the number of terminals and “C phase” as the phase to be protected, and sets the current differential relay at the opposite end. The arithmetic means 9 of the device 4b sets “2 terminals” as the number of terminals and “A phase and B phase” as the phases to be protected. The current differential protection relay devices 4a and 4b make a determination using the settling result and determine the setting of the own device.

With the current differential protection relay devices 4a and 4b set in this manner, the currents I _A , I _B , and I _{C of the} three phases flowing through the transmission line 1a at the terminals where they are installed are current transformers. 2, these currents are converted into voltage signals of a predetermined magnitude by the input converter 6, and after removing harmonic components that cause aliasing errors due to sampling by the analog filter 7, Sampling is performed at a period, and the analog / digital conversion means 8 converts the data into digital data.

  Here, the current differential protection relay device 4a installed at the terminal A is the A phase and B phase 2 out of the current data of each of the three phases of the transmission line 1a converted from the transmission means 11 into digital data. The phase component is transmitted to the current differential protection relay device 4b installed at the terminal B through the transmission line 5. The current differential protection relay 4b installed at the terminal B receives the current data for two phases of the power transmission line 1a transmitted from the terminal A by the receiving means 12, and receives this current data and its own device. The A-phase and B-phase current data of the power transmission line 1a introduced in step S1 is passed to the calculation means 9.

  On the other hand, the current differential protection relay device 4b installed at the terminal B passes one phase of C phase out of the current data of the transmission line 1a converted from the transmission means 11 into digital data via the transmission line 5. The data is transmitted to the current differential protection relay device 4a installed at the terminal A. The receiving means 12 of the current differential protection relay 4a installed at the terminal A receives the current data for one phase of the power transmission line 1a of the terminal B transmitted from the terminal B, and the current data and Then, the C phase current data of the power transmission line 1 a introduced into the own device is passed to the calculation means 9.

  Thus, the current differential of the phase A and B of the power transmission line 1a is transmitted from the terminal A, and the current data of the phase C of the power transmission line 1a is transmitted from the terminal B. The calculation means 9 of the protective relay device 4a collects the current data of the C phase of the transmission line 1a of the terminal A and the terminal B, and the calculation means 9 of the current differential protection relay device 4b installed at the terminal B includes Current data of the A phase and the B phase of the power transmission line 1a of the terminal A and the terminal B is collected.

  This means that the calculation means 9 of the current differential protection relay device 4a at the terminal A can realize the C phase current differential calculation among the current differential calculations for the transmission line 1a, and the current differential protection relay at the terminal B. The arithmetic means 9 of the device 4b means that A-phase and B-phase current differential calculations can be performed among the current differential calculations for the transmission line 1a.

  Note that the method of obtaining the output on the side that cannot be calculated by itself can be realized by the same idea as the first embodiment and the second embodiment, and thus detailed description thereof is omitted.

  As described above, according to the third embodiment of the present invention, the current differential operation of the C phase is performed in the current differential protection relay device 4a installed in the terminal A, and the current differential installed in the terminal B. From the terminal A, the current data of the A phase and the B phase of the power transmission line 1a are transmitted from the terminal A, and from the terminal B, the C phase of the power transmission line 1a so that the protection relay device 4b can perform the current differential calculation of the A phase and the B phase. Current data for one phase or two phases can be reduced compared to the case where current data for three phases is always transmitted as in the prior art. This means that it is possible to transmit the current data, which is conventionally expressed by 12 bits, without reducing the bit length even when the current data is expressed by a number of bits larger than 12 bits.

  Therefore, it is possible to transmit electric quantity data exceeding 12 bits in the case of protection for one transmission line.

  Furthermore, in the present invention, the fourth electric quantity can be transmitted as electric quantity data exceeding 12 bits in the direction from the terminal B to the terminal A. Therefore, the same step-out detection function or zero phase as in the second embodiment is possible. An electric current differential function can also be provided.

(Fourth embodiment)
FIG. 6 is a block diagram showing a fourth embodiment of the present invention. The same components as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  The difference between this embodiment and FIG. 1 is that the transmission of two lines connected to the bus terminal of the C terminal via the circuit breaker 3 in the middle of the transmission lines 1a and 1b of the respective lines connecting the terminals A and B. There exists in the point which connected the electric wires 1a and 1b, and was set as the 3 terminal structure. The terminal C is provided with the current transformer 2, the circuit breaker 3, and the current differential protection relay device 4c in the same manner as the terminals A and B, and the current differential protection relay devices 4a, 4b, Transmission paths 5a, 5b, and 5c for transmitting and receiving current data are connected between 4c.

  In addition, since the structure of the current differential protection relay device 4c is the same as that of the current differential protection relay device 4a, the description and description thereof are omitted.

  Further, in the current differential protection relay devices 4a, 4b, 4c, the current data of the own protection line and the current data to be transmitted to the opposite end are selected based on the number of terminals set by the setting means 14 and the protection line. Since this is the same as in the first embodiment, the description thereof is omitted here.

  Next, the operation of the power line protection relay device configured as described above will be described.

  In the current differential protection relay devices 4a, 4b, and 4c installed from the terminal A to the terminal C, the current flowing through the power transmission lines 1a and 1b at the installed terminals is input through the current transformer 2 When the converter 6 is introduced, the input converter 6 converts the current flowing through each line into a voltage signal of a predetermined magnitude, and after removing harmonic components that cause aliasing errors due to sampling by the analog filter 7, Sampling is performed at a period of, and the analog / digital conversion means 8 converts it into digital data.

  Here, the current differential protection relay device 4a installed at the terminal A installs the current data of the transmission line 1a converted from the transmission means 11 into digital data at the terminals B and C via the transmission line 5a. Is transmitted to the current differential protection relay devices 4b and 4c.

  Next, the current differential protection relay device 4b installed at the terminal B installs the current data of the transmission line 1b converted from the transmission means 11 into digital data at the terminals A and C via the transmission line 5b. To the current differential protection relay devices 4a and 4c.

  Then, the current differential protection relay device 4c installed at the terminal C uses the current data of the transmission line 1a converted from the transmission means 11 to the digital data to the current installed at the terminal B via the transmission line 5c. The data is transmitted to the differential protection relay device 4b, and further, the current data of the transmission line 1b converted into digital data is transmitted to the current differential protection relay device 4a installed at the terminal A through the transmission line 5c. .

  As described above, in the present embodiment, in addition to transmitting the current data of the power transmission line 1a from the terminal A and the current data of the power transmission line 1b from the terminal B, the terminal C of the added third terminal C is the terminal A. Is transmitted to the terminal B, the current data of the power transmission line 1b is collected at the terminal A, and the current of the power transmission line 1a is collected at the terminal B. Make sure the data is gathered.

  As a result, the calculation means 9 of the current differential protection relay device 4a at the terminal A can realize current differential calculation for the transmission line 1b, so that the calculation result is output from the output means 10 of the own apparatus and from the transmission means 11. Transmission to the current differential protection relay devices 4b and 4c at the terminals B and C via the transmission line 5a is performed to protect the power transmission line 1b.

  In addition, since the calculation means 9 of the current differential protection relay device 4b at the terminal B can realize current differential calculation for the power transmission line 1a, the calculation result is output from the output means 10 of the own apparatus and from the transmission means 11 to the transmission line. The protection to the power transmission line 1a is realized by transmitting to the current differential protection relay devices 4a and 4c of the terminals A and C via 5b.

  Furthermore, the current differential protection relay device 4c at the terminal C transmits the current data required by each terminal, and receives the protection output information corresponding to the calculation result sent from each terminal. Acts as a device.

  The above describes the action that is realized when all three terminals are in the normal operation state in the three-terminal configuration, but the action when one terminal is in a suspended or non-use state and is operated as equivalent to two terminals is described below.

  The current differential relay device according to the present embodiment performs the sleep / non-use end zero control, which treats the current data transmitted from the non-use or non-use terminals as zero, similarly to the conventional current differential relay device. carry out. For example, the current differential relay device 4a at the terminal A performs current differential calculation with the current data of the power transmission line 1b from the terminal C as zero, and the current differential relay device 4b at the terminal B performs power transmission from the terminal C. Current differential calculation is performed with the current data of 1a as zero.

  As a result, in the current differential protection relay device 4a at the terminal A, the power transmission line 1b corresponding to the two terminals A and B is protected. In the current differential protection relay device 4b at the terminal B, The power transmission line 1a corresponding to the two terminals A and B is protected.

  This can be considered that the state of the apparatus is equivalent to that of the first embodiment, so that it is obvious that similar actions and effects can be obtained.

  Further, when the terminal A is suspended or not used, it corresponds to the two terminals of the terminal B and the terminal C. In this case, the current differential calculation of the transmission line 1b performed in the current differential protection relay device 4a at the terminal A is lost, but the current differential relay device 4c at the terminal C working as a slave station device is lost. Instead of the current differential relay device 4a at the terminal A, the current differential calculation of the power transmission line 1b can be performed.

  As described above, in the current differential protection relay device 4c at the terminal C, the current data of the power transmission line 1a from the current differential relay device 4a at the terminal A is transmitted from the current differential relay device 4b at the terminal B to the power transmission line 1b. Because the current data is always transmitted, the current data for three terminals is not always available for the power transmission lines 1a and 1b and correct current difference calculation cannot be performed. Is the current data of the power transmission line 1b for the two terminals B and C, and correct current differential calculation of the power transmission line 1b is possible.

  Therefore, when the terminal A is in a dormant or non-use state, the current differential calculation of the power transmission line 1b is performed by the current differential protection relay device 4c of the terminal C functioning as a slave station device.

  Further, when the terminal B is suspended or not used, it corresponds to two terminals of the terminal A and the terminal C.

  In this case, the current differential calculation of the transmission line 1a performed by the current differential protection relay device 4b of the terminal B is lost, but the terminal A and the terminal are the same as when the terminal A is suspended or not used. If it is current data of the power transmission line 1a for two terminals of C, it is gathered at the terminal C.

  Therefore, when the terminal B is in a suspended state or not in use, the current differential operation of the power transmission line 1a is performed by the current differential protection relay device 4c of the terminal C functioning as a slave station device.

  In order to correctly perform the above operation in the current differential protection relay devices 4a, 4b, and 4c, it is possible to realize which current data of the transmission lines 1a and 1b is transmitted from the transmission unit 11 by the calculation unit 9 in each device. According to the current differential calculation and its result, the output to the output means 10 and the output from the transmission means 11 to the opposite end is for the transmission lines 1a and 1b, or is the slave station that does not perform the calculation In the case of a slave station, it is necessary to correctly set which current data of the transmission lines 1a and 1b is transmitted from the transmission means 11 to which terminal.

  In order to realize the setting of the device, the number of terminals, the line to be protected, and the line to be protected by the opposite end device are set from the setting means 14.

  Here, unlike the first embodiment, the line to be protected is set so that “slave station” can be set in addition to “1L protection” and “2L protection”. Only when it is set as “station”, it is necessary to set the line protected by the opposite-end device.

  In this embodiment, the current differential protection relay device 4a is set to “3 terminals” for the number of terminals and “2L protection” to the line to be protected, and the current differential protection relay device 4b is set to the number of terminals. Set “3 terminals” to the line to be protected, “1L protection” to the line to be protected, “3 terminals” to the number of terminals in the current differential protection relay device 4c, and “slave station” to the line to be protected. At the same time, “1L protection” is set for the transmission channel on the side connected to the current differential protection relay device 4a as setting of the line protected by the opposite-end device.

  The current differential protection relay devices 4a, 4b, 4c use this settling result to make a determination according to the flowchart for the three terminals shown on the right side of FIG.

  In the case of this settling, the current differential protection relay device 4a transmits the current data of the power transmission line 1a from the transmission means 11, the current differential calculation that can be realized by the calculation means 9, and the output means according to the result. 10 and output from the transmission means 11 to the opposite end is determined to be for the power transmission line 1b.

  Similarly, the current differential protection relay device 4b transmits the current data of the transmission line 1b from the transmission means 11 and outputs to the output means 10 according to the current differential calculation that can be realized by the calculation means 9 and the result. In addition, it is determined that the output from the transmission means 11 to the opposite end is for the power transmission line 1a.

  In the current differential protection relay device 4c, what is transmitted from the transmission means 11 is current data of the transmission line 1b in the transmission channel connected to the current differential protection relay device 4a. In the transmission channel on the side connected to the relay device 4b, it is determined that the current data of the power transmission line 1a and that the own device is a slave station.

  As described above, in the fourth embodiment of the present invention, even in the three-terminal configuration, the current differential protection relay device 4a installed at the terminal A collects current data of the transmission line 1b and is installed at the terminal B. Since the current data of the transmission line 1a is collected in the current differential protection relay device 4b, the current differential protection relay device 4a at the terminal A can realize the current differential calculation for the transmission line 1b. In the current differential protection relay device 4b at the terminal B, a current differential operation for the power transmission line 1a can be performed. Further, since the protection output information of the power transmission line 1b is transmitted from the terminal A to the terminal B and the terminal C, and the protection output information of the power transmission line 1a is transmitted from the terminal B to the terminal A and the terminal C. It is possible to protect two transmission lines without changing the number of lines or the transmission speed.

  Further, in the three-terminal configuration, even when any one terminal is suspended or not used and becomes equivalent to two terminals, the remaining two-terminal current differential protection relay device has one transmission line 1a. Current data is collected on the other side, and current data on the transmission line 1b is collected on the other side, so that it is possible to protect two transmission lines without changing the number of transmission lines or the transmission speed between devices as described above. Become.

  In the fourth embodiment, the case of the three-terminal configuration has been described, but the same operation and effect can be obtained even in the case of the four-terminal configuration. The outline will be described below with reference to FIG.

  FIG. 7 is a diagram showing current data transmitted between devices at each terminal in a four-terminal configuration.

  As shown in FIG. 7, since the data transmitted from each terminal is only for one line of either the power transmission line 1a or 1b, it is not necessary to change the number of transmission path lines or the transmission speed between apparatuses. When all four terminals are in operation, current data of the transmission line 1b is collected at the terminal A and current data of the transmission line 1a is collected at the terminal B. Therefore, if the terminal C and the terminal D are handled as slave station devices, It can be seen that the same operations and effects as those described in the fourth embodiment can be obtained.

  The current data transmission shown in FIG. 7 is performed even when any one of the four terminals is inactive or unused and corresponds to three terminals, or even when two terminals are inactive or unused and equivalent to two terminals. If the method is adopted and there is current data for the remaining terminals, it can be seen that the current data of the transmission lines 1a and 1b are collected at any two terminals.

  Here, in the case of a four-terminal configuration, there are two devices acting as slave stations, and the current data transmitted between the slave station devices is one of the current data of the transmission line 1a and the other of the current data of the transmission line 1b. This is necessary, but this is the settling means 14 which sets the number of terminals, the line to be protected and the line to be protected by the opposite-end device, as well as the three-terminal configuration, and the own apparatus is set to the slave station. When the current data transmitted between the slave stations is set to determine whether the transmission line is one of the transmission lines 1a and 1b, each device at the terminals A to D uses this settling result to show in the flowchart of FIG. It is possible to make a determination and set the own device correctly.

  FIG. 3 is a flowchart showing the determination contents in the case of the four-terminal configuration subsequent to FIG. 2, and the current differential relay device of each terminal A to D determines the setting of its own device based on this determination. Here, “settling data” in the case of a slave station is data determined by a settling value that specifies which transmission line the current data transmitted between the slave stations is. Two working devices are set to different values.

  Therefore, even in the case of a four-terminal configuration, the number of transmission lines between apparatuses and the transmission speed are not changed, and protection for two transmission lines is possible.

  The above describes that, in a three-terminal or four-terminal configuration, the protection for two transmission lines can be realized without changing the number of transmission lines and the transmission speed between apparatuses as in the first embodiment. Based on the idea, it is clear that the operations and effects described in the second and third embodiments can be realized with a three-terminal or four-terminal configuration.

BRIEF DESCRIPTION OF THE DRAWINGS The block diagram which shows 1st Embodiment of the power transmission line protection system and apparatus by this invention. The flowchart which shows the determination content for determining the setting of an own apparatus using the setting result of the current differential protection relay apparatus of each terminal in 2 terminal structure and 3 terminal structure. The flowchart following FIG. 2 which shows the determination content for determining the setting of an own apparatus using the setting result of the current differential protection relay apparatus of each terminal in 4 terminal structure. The block diagram which shows 2nd Embodiment of the power transmission line protection system and apparatus by this invention. The block diagram which shows 3rd Embodiment of the power transmission line protection system and apparatus by this invention. The block diagram which shows 4th Embodiment of the power transmission line protection system and apparatus by this invention. The schematic block diagram for demonstrating the transmission form of the electric current data of each line | wire between each terminal at the time of applying the power transmission line protection system and apparatus by this invention to 4 terminal structure. The figure which showed the transmission format in the conventional current differential protection relay apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1a, 1b ... Power transmission line, 2 ... Current transformer (CT), 3 ... Circuit breaker (CB), 4a, 4b, 4c ... Current differential protection relay device, 5a-5c ... Transmission path, 6 ... Input converter , 7 ... analog filter, 8 ... analog / digital conversion means, 9 ... calculation means, 10 ... output means, 11 ... transmission means, 12 ... reception means, 13 ... sampling synchronization control means, 14 ... settling means

Claims (8)

  It is installed at each terminal in the power transmission line protection relay system that protects the power transmission line by transmitting and receiving information on the protective relay device provided at each terminal of the power system in which multiple terminals are connected by a power transmission line through the transmission line. Each of the devices is a protection relay device that performs a protection operation for different protection targets, and the amount of electricity required by the partner protection relay device and the own device by a pair of transmission lines connecting the devices. A transmission line protection relay system characterized by transmitting output information of a protection operation result that has been implemented.   The transmission line protection relay system according to claim 1, wherein the devices installed at each terminal are protection relay devices that perform protection calculation for different protection targets of at least two devices, and the devices installed at the remaining terminals. A power transmission line protection relay system, which is a slave station device for a protection relay device that performs the protection calculation.   In a power transmission line protection relay system that protects a two-line power transmission line by transmitting / receiving information of a protective relay device provided at each terminal of a power system in which a plurality of terminals are connected by a two-line power transmission line, One of the terminals is a protection relay device that performs a protection calculation of the first transmission line, and one of the other terminals is a protection relay device that performs a protection calculation of the second transmission line. The transmission line protection relay is characterized by transmitting the electrical quantity data required by the partner protection relay device and the output information of the protection calculation result performed by the own device through a pair of transmission lines connecting the devices. Electric system.   In a power transmission line protection relay system that protects a power transmission line by transmitting / receiving information of a protective relay device provided at each terminal of a power system in which a plurality of terminals are connected by a power transmission line, any one terminal Is a protective relay device that performs protection calculations for short-circuit accidents in power transmission lines, and one of the terminals that is different from this is a protective relay that performs protection calculations for either or both of ground faults and step-out detection of power transmission lines A device is characterized in that, by means of a pair of transmission lines connecting between the devices, the electrical quantity data required by the partner protection relay device and the output information of the protection calculation result performed by the device itself are transmitted. Transmission line protection relay system.   In a power transmission line protection relay system that protects a power transmission line by transmitting / receiving information of a protective relay device provided at each terminal of a power system in which a plurality of terminals are connected by a power transmission line, any one terminal Is a protective relay device that performs protection calculation using current data of two phases of the three phases of the transmission line, and any one terminal different from this uses the current data of the remaining one phase of the three phases of the transmission line A protection relay device that performs the protection calculation, and a pair of transmission lines connecting the devices to each other, the electrical quantity data required by the partner protection relay device and the output information of the protection calculation result performed by the own device, A transmission line protection relay system characterized in that the electric quantity data to be transmitted is expressed by a bit length exceeding 12 bits.   In a digital type current differential protection relay device that is installed at each terminal of an electric power system in which a plurality of terminals are connected by a power transmission line, detects the occurrence of an accident within the protection section from the current information of each terminal, and performs a predetermined output A / D conversion means for performing digital conversion by sampling the electric quantity at its own end based on a sampling signal, and transmission means for outputting information on its own end including electric quantity data output from this A / D conversion means Receiving means for receiving data transmitted via a communication medium from the current differential protection relay device of the opposite terminal, and a protection calculation from the electric quantity data of the own terminal and the opposite terminal obtained from the transmitting means and the receiving means And a sampler for controlling the sampling signal at the same timing at each terminal. Synchronization control means, the computing means performs protection computations for different protection targets in the opposing device, and the transmitting means is the opposing device and the electrical quantity data required by the counterpart device and the device A digital type current differential protection relay device which transmits predetermined data based on a calculation result of a calculation means.   Digital type current differential protection relay that is installed at each terminal of the power system that connects two or more terminals with a two-line transmission line, detects the occurrence of an accident within the protection section from the current information of each terminal, and outputs a predetermined output In the apparatus, A / D conversion means for performing digital conversion by sampling its own electric quantity based on a sampling signal, and transmission for outputting its own information including electric quantity data output from this A / D conversion means Means, receiving means for receiving data transmitted from the current differential protection relay device of the opposing terminal via the communication medium, and the electric quantity data of the own terminal and the opposing terminal obtained from the transmitting means and the receiving means An arithmetic unit that performs a protection operation, an output unit that performs a predetermined output according to the result of the arithmetic unit, and a control unit that controls the sampling signal so that the timing is the same at each terminal. Pulling synchronization control means, wherein the computing means performs protection computation for protection of transmission lines of different lines at the opposing device, and the transmitting means is the opposing device for the line required by the partner device. A digital type current differential protection relay device which transmits electric quantity data and predetermined data based on a calculation result of the calculation means.   Digital type current differential protection relay that is installed at each terminal of the power system where multiple terminals are connected by a transmission line and detects the occurrence of an accident inside the protection section from the current information of each terminal and outputs a predetermined output In the apparatus, A / D conversion means for performing digital conversion by sampling its own electric quantity based on a sampling signal, and transmission for outputting its own information including electric quantity data output from this A / D conversion means Means, receiving means for receiving data transmitted from the current differential protection relay device of the opposing terminal via the communication medium, and the electric quantity data of the own terminal and the opposing terminal obtained from the transmitting means and the receiving means Control means for performing a protection calculation, output means for performing a predetermined output according to the calculation result of the calculation means, and controlling the sampling signal so as to have the same timing at each terminal Sampling synchronization control means, wherein the calculation means performs protection calculations for different phases in the opposite device, and the transmission means is a predetermined amount based on the electric quantity data of the phase used in the opposite device and the calculation result of the calculation means. The digital current differential protection relay device is characterized in that the electric quantity data to be transmitted is expressed by a bit length exceeding 12 bits.

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