CN115498774B - Microcomputer type distribution automation station terminal based on multi-line measurement and control - Google Patents
Microcomputer type distribution automation station terminal based on multi-line measurement and control Download PDFInfo
- Publication number
- CN115498774B CN115498774B CN202211327776.5A CN202211327776A CN115498774B CN 115498774 B CN115498774 B CN 115498774B CN 202211327776 A CN202211327776 A CN 202211327776A CN 115498774 B CN115498774 B CN 115498774B
- Authority
- CN
- China
- Prior art keywords
- line
- voltage
- module
- current
- control
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J13/00—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
- H02J13/00002—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by monitoring
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/08—Locating faults in cables, transmission lines, or networks
- G01R31/081—Locating faults in cables, transmission lines, or networks according to type of conductors
- G01R31/085—Locating faults in cables, transmission lines, or networks according to type of conductors in power transmission or distribution lines, e.g. overhead
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
- G01R31/52—Testing for short-circuits, leakage current or ground faults
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/02—Details
- H02H3/06—Details with automatic reconnection
- H02H3/066—Reconnection being a consequence of eliminating the fault which caused disconnection
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/08—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current
- H02H3/093—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current with timing means
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
- H02H7/261—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured involving signal transmission between at least two stations
- H02H7/262—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured involving signal transmission between at least two stations involving transmissions of switching or blocking orders
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
- H02H7/261—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured involving signal transmission between at least two stations
- H02H7/263—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured involving signal transmission between at least two stations involving transmissions of measured values
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J13/00—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
- H02J13/00001—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by the display of information or by user interaction, e.g. supervisory control and data acquisition systems [SCADA] or graphical user interfaces [GUI]
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J13/00—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
- H02J13/00032—Systems characterised by the controlled or operated power network elements or equipment, the power network elements or equipment not otherwise provided for
- H02J13/00036—Systems characterised by the controlled or operated power network elements or equipment, the power network elements or equipment not otherwise provided for the elements or equipment being or involving switches, relays or circuit breakers
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J13/00—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
- H02J13/00032—Systems characterised by the controlled or operated power network elements or equipment, the power network elements or equipment not otherwise provided for
- H02J13/00036—Systems characterised by the controlled or operated power network elements or equipment, the power network elements or equipment not otherwise provided for the elements or equipment being or involving switches, relays or circuit breakers
- H02J13/0004—Systems characterised by the controlled or operated power network elements or equipment, the power network elements or equipment not otherwise provided for the elements or equipment being or involving switches, relays or circuit breakers involved in a protection system
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Human Computer Interaction (AREA)
- Remote Monitoring And Control Of Power-Distribution Networks (AREA)
Abstract
The application relates to a microcomputer type power distribution automation station terminal based on multi-line measurement and control, which particularly comprises a communication module, a remote signaling module, a control module, a power module, a display module and a main board module, wherein the control module is configured with fault direction detection and line abnormality detection, the line abnormality detection comprises jump current alarm and PT wire breakage detection, and when the power distribution terminal is in closed-loop operation and/or connected with a distributed power supply, the fault direction detection operation is carried out, and each line overcurrent protection and zero sequence overcurrent direction element is respectively switched on and off; when the measured value of the line current is not smaller than the fixed value of the overload current, the overload protection control word is in a put-in state, and a load outlet or a load alarm is selected; the application has the functions of fault detection and fault discrimination, can upload fault alarm information, has the functions of real-time control, parameter setting and safety protection, and can automatically, accurately and real-time measure and control the running state of a line so as to realize all-weather on-line management of the state of a station terminal.
Description
Technical Field
The application relates to the technical field of power distribution automation, in particular to a microcomputer type power distribution automation station terminal based on multi-line measurement and control.
Background
The station terminal (DTU) is a wireless terminal device which is specially used for converting serial data into IP data or converting IP data into serial data to be transmitted through a wireless communication network, is suitable for multi-loop centralized monitoring application occasions such as a distribution room, a ring main unit, an opening and closing station, a box-type transformer substation and the like, has the functions of alternating current sampling, direct current telemetry, remote control, remote signaling, wave recording, clock synchronization, event sequence recording, multi-serial communication, various communication protocols, distributed network communication, local or remote online loading or updating of application software, parameter setting, remote diagnosis maintenance and the like, can store large-capacity data, can be matched with a communication system to form various ring networks and non-ring network distribution automation systems with channel modes, and is matched with an electronic distribution station and a master station to realize the function of monitoring the running states of distribution lines and distribution terminals.
The traditional station terminal line detection mainly accesses corresponding test equipment when the terminal fails, the real-time detection of the terminal cannot be realized, the line state parameters are various, the line state cannot be mastered in time, and an automatic, accurate and real-time monitoring mode is needed when the terminal fails to realize all-weather online detection and management of the station terminal state.
Disclosure of Invention
The application aims to overcome the defects of the prior art, provides a microcomputer type power distribution automation station terminal based on multi-line measurement and control, and solves the measurement and control problem of the station terminal in the prior art.
In order to achieve the above purpose, the technical scheme of the application is specifically realized as follows: a microcomputer type distribution automation station terminal based on multi-line measurement and control comprises a communication module, a communication module and a communication module, wherein the communication module is used for communicating with appointed PLC equipment, a distribution substation, a communication master station and/or a host computer;
the remote signaling module comprises a remote signaling unit, a remote signaling unit and a remote control unit, wherein the remote control unit comprises n (n is more than 2) groups of remote control lines for providing switching-on and switching-off control output for a power distribution terminal, each group of remote control lines comprises a switching-on line, a switching-off line and a switching-on and switching-off public line, the remote signaling unit collects three-phase current, three-phase voltage, zero sequence current, zero sequence voltage, public terminal voltage and frequency of each remote control line, the remote signaling unit comprises at least 2n (n is more than 2) remote signaling contacts, and each group of remote control lines is configured with at least 4 remote signaling contacts;
the control module is configured with fault direction detection and line abnormality detection, wherein the line abnormality detection comprises jump bit current alarm and PT broken line detection, and when the power distribution terminal is in closed loop operation and/or connected with a distributed power supply, the fault direction detection operation is carried out, and each line overcurrent protection and zero sequence overcurrent direction element is respectively switched on and off; when the measured value of the line current is not smaller than the fixed value of the overload current, the overload protection control word is in a put-in state, and a load outlet or a load alarm is selected;
the power module comprises a power supply module, a power management module, a standby power supply module and a switching module, wherein the switching module is used for switching the power supply path of the terminal;
the display module is used for displaying the running state, the communication state, the remote signaling state, the menu, the operation interface and the alarm information of the terminal;
and the main board module is connected with the communication module, the remote signaling module, the control module, the power module and the display module to control power supply.
Preferably, the fault direction detection includes phase-to-phase fault detection and single-phase earth fault detection, and the direction of current flowing out of the bus is set to be the positive direction, otherwise, the direction element with the memorized positive sequence voltage as the polarization amount is adopted in the phase-to-phase fault detection, the 0-degree wiring mode is adopted, the sensitive angle of the direction element is set to be 45 degrees, and the positive sequence voltage of the same-name phase is compared with the phase current:
positive direction:
and the reverse direction:
when single-phase earth fault detection is performed: the direction element is composed of zero sequence voltage and zero sequence current, the sensitive angle is set to-100 DEG, and the zero sequence voltage and the zero sequence current are compared in phase:
positive direction:
and the reverse direction:
preferably, when the jump bit has a flow alarm to start, a circuit has current, and meanwhile, the jump bit is opened to discharge reclosing; PT broken wire detects and is used for detecting whether single-phase broken wire, two-phase broken wire or three-phase broken wire appear in the circuit:
a) The three-phase voltages are smaller than 16V, and at least one phase of current is larger than no current, and the three-phase voltage is judged to be a three-phase disconnection;
b) The maximum line voltage is greater than 50V, the minimum line voltage is less than 16V, and the two-phase broken line is judged;
c) The maximum line voltage is greater than 90V, the minimum line voltage is less than 70V, and the single-phase line breakage is judged;
any one of the criteria is met, and the display module displays PT broken line; PT broken line detection is controlled to be switched on and off by the control module.
Preferably, the overload protection performance satisfies the following condition:
K r I max ≤I s ≤I max ，
wherein: i s For overload protection of the operating current, K r The value range is 0.8-0.9 for the reliable coefficient; i max Is the maximum load current value of the line.
Preferably, each line is provided with the reclosure, and the reclosure meets any one of the following conditions to be immediately discharged and simultaneously to be blocked:
1) Reclosing and exiting;
2) Manual tripping (manual tripping, remote tripping);
3) Overload warning;
4) Reclosing to generate a closing pulse;
5) The switch gives an alarm on two positions;
6) Before reclosing is started, the spring is received to store no energy or low-pressure locking signal, and the discharge is performed for 400ms after time delay.
Preferably, each circuit is provided with two-section overcurrent protection for interphase fault treatment, protection current is started according to phases, each section of protection is selectively put into a power-losing tripping condition, and after the overcurrent tripping condition is put into and overcurrent starting delay is met, a protection action outlet of the power-losing condition is detected within 500 ms; when any phase current of the three-phase currents exceeds a fixed value and the direction is in an action area and harmonic waves are not locked, starting delay, enabling the delay to meet the requirement of post action, and enabling the action to select overcurrent alarming or overcurrent opening to be respectively switched on and off.
Preferably, the control module is configured with a non-interrupt current protection, a circuit breaker is mounted on each line, when the line fault current is detected to exceed the non-interrupt current fixed value, the non-interrupt current is locked to the protection tripping input, the protection tripping outlet is locked, and the circuit breaker cuts off the fault line.
Preferably, the control module is configured with automatic disconnection, the automatic disconnection includes automatic disconnection of voltage out of limit and automatic disconnection of frequency out of limit, and a three-wire voltage discrimination mode is adopted for controlling automatic control voltage disconnection locking and opening of the network points on the power supply.
Preferably, the automatic voltage threshold-crossing disconnection includes the following four functions:
(1) automatic splitting of too low a voltage: when the voltage is lower than or equal to 50% Un, automatically opening the gate after time delay;
(2) automatic splitting of overvoltage: when the voltage is higher than or equal to 135% Un, the switch is automatically opened after time delay;
(3) low voltage automatic splitting: when the voltage is between 50% Un and UL, the brake is automatically opened after the time delay TUL;
(4) high voltage automatic splitting: when the voltage is UH-135%Un, the brake is automatically opened after TUH is delayed;
wherein Un is the on-off public line voltage, UL is the low voltage fixed value, UH is the overvoltage fixed value, TUL is the low voltage time limit, and TUH is the high voltage time limit.
Preferably, the frequency-out-of-limit automatic separation includes the following three sub-functions:
(1) automatic splitting with too low a frequency: when the frequency is lower than or equal to 47.0Hz and is higher than 44.0Hz, automatically opening the valve;
(2) low frequency automatic splitting: when the frequency is between 47.0Hz and fL, the gate is automatically opened after TfL is delayed;
(3) high frequency automatic splitting: when the frequency is between fH and 55.0Hz, the automatic brake opening is performed after the time delay TfH;
wherein fL is a low frequency fixed value, tfL is a low frequency time limit, fH is a high frequency fixed value, and TfH is a high frequency time limit.
The application has the beneficial effects that:
compared with the prior art, the microcomputer type power distribution automation station terminal based on multi-line measurement and control has the functions of fault detection and fault discrimination, can upload fault alarm information, has the functions of real-time control, parameter setting and safety protection, can automatically, accurately and real-time measure and control the running state of a line so as to realize all-weather on-line management of the state of the station terminal, and is communicated with appointed PLC equipment, a communication master station and/or a host computer through a communication module, thereby being beneficial to remote monitoring of an electronic distribution station and the master station and enabling centralized control type multi-channel measurement and control automation to be correctly realized.
Drawings
The application will now be described in further detail with reference to the drawings and to specific examples.
Fig. 1 is a schematic diagram of a microcomputer type power distribution automation station terminal based on multi-line measurement and control in the present embodiment;
fig. 2 is a schematic diagram of a communication interface of a terminal of the microcomputer type power distribution automation station based on multi-line measurement and control in the embodiment;
fig. 3 is a schematic diagram showing connection between a remote control unit and a power distribution terminal of a microcomputer type power distribution automation station terminal based on multi-line measurement and control in the embodiment;
fig. 4 is a schematic diagram of an ac sampling connection of one path of a telemetry unit of a microcomputer type power distribution automation station terminal based on multi-line measurement and control in the present embodiment;
fig. 5 is a schematic diagram of a remote signaling unit remote signaling amount connection of a microcomputer type distribution automation station terminal based on multi-line measurement and control in the present embodiment;
fig. 6 is a block diagram of reclosing actions and charging and discharging logic of a microcomputer type distribution automation station terminal based on multi-line measurement and control in the embodiment;
fig. 7 is a logic block diagram of overload protection of a microcomputer type power distribution automation station terminal based on multi-line measurement and control in the present embodiment;
fig. 8 is a logic diagram of an overcurrent protection operation of a microcomputer type power distribution automation station terminal based on multi-line measurement and control in the embodiment;
FIG. 9 is a logic diagram of non-interrupt current protection for a microcomputer type distribution automation station terminal based on multi-line measurement and control in the present embodiment;
fig. 10 is a schematic diagram of a power module of a microcomputer type power distribution automation station terminal based on multi-line measurement and control in the present embodiment.
Detailed Description
The following description of the embodiments of the present application will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to fall within the scope of the application.
The operation logic of the microcomputer type power distribution automation station terminal based on multi-line measurement and control provided by the embodiment of the application comprises the following steps of:
referring to fig. 1, a microcomputer type power distribution automation station terminal based on multi-line measurement and control has communication, measurement, protection, control and power distribution automation functions, and specifically includes a communication module 1, a remote signaling module 2, a control module 3, a power module 4, a display module 5 and a main board module 6, wherein the main board module 6 is connected with the communication module 1, the remote signaling module 2, the control module 3, the power module 4 and the display module 5 to control power supply, and the power module 4 supplies power to the communication module 1, the remote signaling module 2, the control module 3 and the display module 5 through the main board module 6.
The communication module 1 is configured to communicate with a designated PLC device, a power distribution substation, a communication master station and/or a host computer, where the communication mode may select optical fiber, RS232, RS485 and ethernet communication, and the designated PLC device, the power distribution substation, the communication master station and/or the host computer may monitor the operation conditions of the terminal and the power distribution terminal in real time through the communication module 1, and an interface schematic diagram of the communication module 1 is shown in fig. 2. In this embodiment, the communication module 1 specifically uses a femtocell MPC8309 processor as a main controller for communicating with a remote communication master station, and in addition, the communication module 1 is configured with an acquisition unit for acquiring analog signal quantities, where the acquisition unit is preferably an altela MAX II series FPGA, and performs synchronous acquisition for multiple signals. In this embodiment, the power distribution terminal is a switch cabinet, and in other embodiments, the power distribution terminal may also be a ring main unit or a power distribution network.
The station terminal is electrically connected with the power distribution terminal, the remote signaling module 2 comprises a remote signaling power supply, a remote sensing unit, a remote signaling unit and a remote control unit, the remote control unit comprises n (n is more than 2) groups of remote control lines and remote control power supplies, the remote control lines provide switching-on and switching-off control output for the power distribution terminal, each group of remote control lines comprise a switching-on line, a switching-off line and a switching-on and switching-off public line (refer to fig. 3), the switching-on line and the switching-off line are combined to form a remote signaling loop, the switching-on line and the switching-off line are used for switching-on and switching-off control on the power distribution terminal, wherein the switching-on line, the switching-off line and the switching-on and switching-off public line are respectively connected to a switching-on outlet, a switching-off outlet and a switching-off public end of the station terminal, and the switching-on and switching-off public line adopt passive contact output. The output voltage of the remote control power supply is DC48V or DC24V, and the remote control power supply is electrically connected with the power distribution terminal, and when the operation power supply is provided from the power distribution terminal, the power supply is not required to be provided from the remote control power supply.
The remote measuring unit is divided into an electromagnetic sampling plate and an electronic sampling plate, the single sampling plate collects 1 path PT and 3 paths CT, the Y-Y connection method, the V-V connection method and the independent zero sequence and synthetic zero sequence connection method are met, the sampling plate is identified and edited by the main board module 6 to define each hardware sampling channel, the single sampling plate can collect at least 16 remote signaling points, the sampling plate is provided with an independent power jumper to select active and passive, and the hardware connection points are provided with hardware anti-shake and signal indicating lamps. The telemetry unit collects three-phase currents (Ia, ib, ic), three-phase voltages (Ua, uc), zero-sequence currents (I0), zero-sequence voltages (U0), public terminal voltages (Un) and frequencies of each path of remote control line, so that analog quantities of multiple paths of remote control lines can be monitored and collected, the analog quantities collected by the telemetry unit are shown in table 1, and a wiring schematic diagram of one path of alternating current sampling of the telemetry unit is shown in fig. 4.
The remote signaling unit comprises at least 2n (n is more than 2) remote signaling contacts and a remote signaling power supply, each group of remote control lines is provided with at least 4 remote signaling contacts and 1 remote signaling power supply positive electrode YXPOW+, and the remote signaling quantity is provided by the remote signaling contacts and a power distribution terminal. In this embodiment, the remote signaling amounts YX1 to YX8 are provided by remote signaling contacts, and referring to fig. 5, the definition of the remote signaling amount of the remaining remote signaling amounts accessed by the power distribution terminal corresponds to the remote signaling of the power distribution terminal side. In a preferred embodiment, n is preferably 4 to 16, that is, the station terminal is capable of implementing remote signaling monitoring through 4 to 16 paths of remote signaling loops, and is provided with 4 to 16 two-position remote signaling processes, so that the preferential transmission of remote signaling displacement can be implemented.
The control module 3 is capable of controlling a remote control line configured with fault direction detection, control loop detection, line anomaly detection and overload protection. The control module 3 can control 16 groups of remote control lines at most, the power supply module 4 supplies power through the main board module 6, the high-sensitivity high-load relay is adopted for controlling output, the internal 1-path preset relay and the 32-path opening relay are adopted, and the ID is identified and edited by the main board module 6 to define the opening contact of each hardware.
Fault direction detection: when the power distribution terminal is in closed-loop operation and/or connected with a distributed power supply, the fault direction detection operation is carried out, and the overcurrent protection and zero-sequence overcurrent direction elements of each line are respectively switched on and off. The fault direction detection comprises interphase fault detection and single-phase grounding fault detection, the direction of current flowing out of a bus is set to be the positive direction, otherwise, the direction element with the memorized positive sequence voltage as the polarization amount is adopted during interphase fault detection, the 0-degree wiring mode is adopted, the sensitive angle of the direction element is set to be 45 degrees, and the phase comparison is carried out between the positive sequence voltage of the same-name phase and the phase current:
positive direction:
and the reverse direction:
when single-phase earth fault detection is performed: the direction element is composed of zero sequence voltage and zero sequence current, the sensitive angle is set to-100 DEG, and the zero sequence voltage and the zero sequence current are compared in phase:
positive direction:
and the reverse direction:
the magnitude of the zero sequence current and the magnitude of the zero sequence voltage are used for judging whether the ground fault occurs, and the phase included angle of the magnitude of the zero sequence current and the magnitude of the zero sequence voltage is used for judging the occurrence direction of the ground fault, so that the power failure protection device has a directional protection function on the power supply side and the load side of the fault, the power failure range of a non-fault area can be reduced, and the detection and power supply reliability is improved.
And (3) detecting a control loop: when the control word is thrown in the 'control loop detection', the control loop abnormality is judged as the control loop abnormality when the jump and the closing of the jump are detected, the control loop disconnection is judged as the control loop abnormality when the jump and the closing of the jump are not detected, the control loop abnormality is delayed for 10s in both cases, and the display module 5 reports the 'control loop abnormality', and the control loop abnormality is checked by the control loop to throw and retreat.
Line anomaly detection: the line abnormality detection comprises a jump bit current alarm and PT disconnection detection, wherein when the jump bit current alarm is started, the line has current, and meanwhile, the jump bit is opened to discharge reclosing; the PT broken wire detection is used for detecting whether a single-phase broken wire, a two-phase broken wire or a three-phase broken wire occurs in a circuit, and the judging mode is as follows:
a) The three-phase voltages are smaller than 16V, and at least one phase of current is larger than no current, and the three-phase voltage is judged to be a three-phase disconnection;
b) The maximum line voltage is greater than 50V, the minimum line voltage is less than 16V, and the two-phase broken line is judged;
c) The maximum line voltage is greater than 90V, the minimum line voltage is less than 70V, and the single-phase line breakage is judged;
any of the above criteria is met, and the display module 5 displays "PT disconnection"; and the PT wire breakage detection is controlled by the control module to switch, and when the PT wire breakage detection detects that single-phase wire breakage, two-phase wire breakage or three-phase wire breakage occurs, reclosing is started.
As a preferred implementation mode of the application, each line is provided with the reclosure, and the reclosure starting mode is protection starting and reclosure charging: after closing, judging that the circuit breaker is at the closing position, and completing charging after the set time. When the switch is in the on position, the reclosing function is put in, the protection is not started, and no other discharging conditions exist, the reclosing charging completion mark is set through the reclosing charging time tCD (about 15 s).
The reclosing switch is immediately discharged and simultaneously closed when any one of the following conditions is met:
1) Reclosing and exiting;
2) Manual tripping (manual tripping, remote tripping);
3) Overload warning;
4) Reclosing to generate a closing pulse;
5) The switch gives an alarm on two positions;
6) Before reclosing is started, the spring is received to store no energy or low-pressure locking signal, and the discharge is performed for 400ms after time delay. After the reclosing charging is finished, the protection action trips and immediately starts the reclosing action when the three-phase no-current triggers the reclosing, a closing pulse is immediately output after the reclosing setting time (about 10 s), the closing pulse width can be set, and when the detection current is larger than the heavy current closing resetting value after the heavy current closing resetting input, the reclosing is closed. The reclosing principle block diagram is shown in fig. 6.
Besides action closing, the reclosing outlet is provided with a post acceleration mark, the number of reclosing times is reduced by one, and the reclosing mark is arranged in parallel and used for preparing for the next reclosing. And after overcurrent or time-limited quick-break tripping and reclosing, if the reclosing is in a permanent fault, the tripping can be accelerated afterwards, and the reclosing is not charged after the tripping.
Overload protection: referring to fig. 7, when the line current measurement value is not less than the overload current fixed value, the overload protection control word is in the put-in state, and a load outlet or a load alarm is selected. The action characteristic of the overload protection meets the following conditions:
K r I max ≤I s ≤I max ，
wherein: i s For overload protection of the operating current, K r The value range is 0.8-0.9 for the reliable coefficient; i max Is the maximum load current value of the line, wherein K r I max The overload current is fixed.
Overcurrent protection: each line is provided with two-section overcurrent protection for interphase fault treatment, and protection current is started according to the phase. As the distribution transformer is connected to the outgoing line, when the feed-out line is switched on, obvious excitation surge current can occur, and in order to avoid protection misoperation, second harmonic locking is arranged, and the second harmonic coefficient is set to 15% of fundamental current. The protection of each section adopts the same directional element, and each section of directional element and harmonic wave can be respectively and independently thrown and retracted. Each section of protection selectively inputs a power-losing tripping condition, and when the overcurrent tripping condition is input and the overcurrent starting delay is met, a protection action outlet of the power-losing condition is detected within 500 ms; when any one phase current of the three-phase currents (Ia, ib and Ic) exceeds a fixed value and the direction is in an action area and harmonic wave is not locked, starting delay, enabling the delay to meet the post action, enabling the action to select an overcurrent alarm or an overcurrent outlet, and enabling the overcurrent alarm or the overcurrent outlet to be respectively switched on and off, wherein the operation logic of the overcurrent protection is shown in figure 8.
In order to prevent misoperation of units when a large-capacity transformer of a user is switched on, one or more of three-phase currents (Ia, ib and Ic) are protected to exceed a set current value, characteristic identification is carried out on exciting inrush current in a current loop by inrush current blocking, and when the second harmonic content of a corresponding phase is measured to exceed an inrush current blocking fixed value, instantaneous large current impact is considered, and an inrush current blocking outlet does not act. The inrush current locking and two-section current protection are matched, the inrush current locking fixed value can be set, and the inrush current locking fixed value can be selectively input/output through the soft pressing plate.
The control module is configured with non-interrupt current protection, a set value of 'non-interrupt current fixed value' and a control word of 'non-interrupt current locking protection trip'. A breaker is arranged on each line, so that the short-circuit current exceeds the breaking current of the breaker when the line is in short-circuit fault, and the breaker can be damaged when the line is disconnected. When the line fault current is detected to exceed the non-interruption current fixed value, the non-interruption current is locked and protected to be tripped, a tripping outlet is locked, the circuit breaker cuts off the fault line, and the non-interruption current protection logic is as shown in figure 9.
The control module is configured with automatic disconnection, and the automatic disconnection can realize overvoltage protection, low-voltage protection, over-frequency protection and low-frequency protection functions, and is generally only applied to network points on a power supply. The automatic disconnection comprises automatic disconnection of voltage out-of-limit and automatic disconnection of frequency out-of-limit, and adopts a three-wire voltage discrimination mode for controlling automatic control voltage disconnection locking and opening of the network points on the power supply. The automatic voltage out-of-limit disconnection comprises the following four functions:
(1) automatic splitting of too low a voltage: when the voltage is lower than or equal to 50% Un, automatically opening the gate after time delay;
(2) automatic splitting of overvoltage: when the voltage is higher than or equal to 135% Un, the switch is automatically opened after time delay;
(3) low voltage automatic splitting: when the voltage is between 50% Un and UL, the brake is automatically opened after the time delay TUL;
(4) high voltage automatic splitting: when the voltage is UH-135%Un, the brake is automatically opened after TUH is delayed;
wherein Un is the on-off public line voltage, UL is the low voltage fixed value, UH is the overvoltage fixed value, TUL is the low voltage time limit, and TUH is the high voltage time limit.
The automatic frequency out-of-limit separation comprises the following three sub-functions:
(1) automatic splitting with too low a frequency: when the frequency is lower than or equal to 47.0Hz and is higher than 44.0Hz, automatically opening the valve;
(2) low frequency automatic splitting: when the frequency is between 47.0Hz and fL, the gate is automatically opened after TfL is delayed;
(3) high frequency automatic splitting: when the frequency is between fH and 55.0Hz, the automatic brake opening is performed after the time delay TfH;
wherein fL is a low frequency fixed value, tfL is a low frequency time limit, fH is a high frequency fixed value, and TfH is a high frequency time limit.
The power module 4 comprises a power supply module, a power management module, a standby power module and a switching module, wherein the power module is connected with the switching module, the switching module and the standby power module are connected with the power management module, and the switching module is used for switching the power supply path of the terminal. In detail, the power supply module adopts a two-way power supply input mode, the power supply module adopts a 220V or 110V alternating current power supply mode, under normal conditions, a first path of alternating current power supply is preferentially selected for power supply, once the first path of alternating current power supply is interrupted, the power supply module automatically switches to a second path of alternating current power supply for power supply, and the power supply module adopts commercial power for power supply; when the first path of alternating current power supply resumes the power supply, the terminal automatically switches back to the first path of alternating current power supply for power supply. The standby power supply module adopts a maintenance-free valve-controlled lead-acid storage battery or a super capacitor, and when the power supply of the power supply module is insufficient or disappears, the power supply module 4 can automatically switch to the standby power supply in a seamless manner to supply power and give an alarm signal. The principle of operation of the power module 4 is described with reference to fig. 10. The power management module is connected with the main board module 6, the remote control power supply and the remote signaling power supply, and the main board module 6 supplies power to the communication module 1, the remote signaling power supply, the control module 3 and the display module 5.
The display module 5 adopts an independent 32-bit MCU to drive display content, a 240X 240 monochromatic lattice LCD is used as a display screen, an up-down left-right navigation key and a confirmation and return/return keyboard are used as operation keys, a power supply of the display module 5 and CAN bus communication are connected with the main board module 6 through a bus board, a u8g2 monochromatic liquid crystal software package is adopted for GUI design, real-time synchronization of main board menu display and content CAN be realized by a protocol, and the display module is used for displaying running states, communication states, remote signaling states, menus, operation interfaces and alarm information of a terminal.
The microcomputer type distribution automation station terminal based on multi-line measurement and control has the functions of fault detection and fault discrimination, can upload fault alarm information, has the functions of real-time control, parameter setting and safety protection, can automatically, accurately and real-time measure and control the running state of a line to realize all-weather on-line management of the station terminal state, is communicated with appointed PLC equipment, a communication master station and/or a host computer through a communication module, is favorable for remote monitoring of an electronic distribution station and the master station, enables centralized control type multi-way measurement and control automation to be accurately realized, is provided with the functions of overcurrent and overload protection, can quickly discriminate and cut off faults when faults occur, is suitable for multi-loop centralized monitoring application occasions such as a distribution room, a ring main unit, an switching station, a box-type transformer substation and the like, and can realize the functions of distribution network automation such as running state monitoring, fault identification, fault isolation, power supply restoration of non-fault areas and the like of the distribution line.
While the foregoing description of the embodiments of the present application has been presented in conjunction with the drawings, it should be understood that it is not intended to limit the scope of the application, but rather, it is intended to cover all modifications or variations within the scope of the application as defined by the claims of the present application.
Table 1 shows the analog quantity collected by the telemetry unit
Claims (8)
1. A microcomputer type distribution automation station terminal based on multi-line measurement and control is characterized in that: comprising
A communication module (1) for communicating with a designated PLC device, a power distribution substation, a communication master station and/or a host computer;
a remote signaling module (2) comprising a telemetry unit, a remote signaling unit and a remote control unit, wherein the remote control unit comprises n groups of remote control lines for providing switching-on and switching-off control output for a power distribution terminal, n is more than 2, each group of remote control lines comprises a switching-on line, a switching-off line and a switching-on and switching-off public line, the telemetry unit collects three-phase current, three-phase voltage, zero sequence current, zero sequence voltage, public terminal voltage and frequency of each remote control line, the remote signaling unit comprises at least 2n remote signaling contacts, n is more than 2, and each group of remote control lines is configured with at least 4 remote signaling contacts;
the control module (3) is configured with fault direction detection, line abnormality detection and overload protection, wherein the line abnormality detection comprises jump current alarm and PT broken line detection, and when the power distribution terminal is in closed-loop operation and/or connected with a distributed power supply, the fault direction detection operation is carried out, and each line overcurrent protection and zero sequence overcurrent direction element is respectively switched on and off; when the measured value of the line current is not smaller than the fixed value of the overload current, the overload protection control word is in a put-in state, and a load outlet or a load alarm is selected;
the power module (4) comprises a power supply module, a power management module, a standby power supply module and a switching module, wherein the switching module is used for switching the power supply path of the terminal;
the display module (5) is used for displaying the running state, the communication state, the remote signaling state, the menu, the operation interface and the alarm information of the terminal;
the main board module (6) is connected with the communication module (1), the remote signaling module (2), the control module (3), the power module (4) and the display module (5) to control power supply;
the fault direction detection comprises interphase fault detection and single-phase grounding fault detection, the direction of current flowing out of a bus is set to be the positive direction, otherwise, the direction element with the memorized positive sequence voltage as the polarization amount is adopted during interphase fault detection, the 0-degree wiring mode is adopted, the sensitive angle of the direction element is set to be 45 degrees, and the phase comparison is carried out between the positive sequence voltage of the same-name phase and the phase current:
positive direction:
and the reverse direction:
when single-phase earth fault detection is performed: the direction element is composed of zero sequence voltage and zero sequence current, the sensitive angle is set to-100 DEG, and the zero sequence voltage and the zero sequence current are compared in phase:
positive direction:
and the reverse direction:
the action characteristic of the overload protection meets the following conditions:
K r I max ≤I s ≤I max ，
wherein: i s For overload protection of the operating current, K r Can be made intoThe value range is 0.8-0.9 by the coefficient; i max Is the maximum load current value of the line.
2. The microcomputer type power distribution automation station terminal based on multi-line measurement and control as set forth in claim 1, wherein: when the jump bit has a current alarm and is started, a circuit has current, and meanwhile, the jump bit is opened to discharge reclosing; PT broken wire detects and is used for detecting whether single-phase broken wire, two-phase broken wire or three-phase broken wire appear in the circuit:
a) The three-phase voltages are smaller than 16V, and at least one phase of current is larger than no current, and the three-phase voltage is judged to be a three-phase disconnection;
b) The maximum line voltage is greater than 50V, the minimum line voltage is less than 16V, and the two-phase broken line is judged;
c) The maximum line voltage is greater than 90V, the minimum line voltage is less than 70V, and the single-phase line breakage is judged;
any one of the criteria is met, and the display module (5) displays PT broken line; PT disconnection detection is controlled to be switched back and forth by the control module (3).
3. The microcomputer type power distribution automation station terminal based on multi-line measurement and control as set forth in claim 1, wherein: each line is provided with a reclosing switch, and any one of the following conditions is immediately discharged and simultaneously closed:
1) Reclosing and exiting;
2) Manual tripping, including manual tripping and remote control tripping;
3) Overload warning;
4) Reclosing to generate a closing pulse;
5) The switch gives an alarm on two positions;
6) Before reclosing is started, the spring is received to store no energy or low-pressure locking signal, and the discharge is performed for 400ms after time delay.
4. The microcomputer type power distribution automation station terminal based on multi-line measurement and control as set forth in claim 1, wherein: each circuit is provided with two-section type overcurrent protection for interphase fault treatment, protection current is started according to phases, each section of protection selectively inputs a power-losing tripping condition, and after the input of the overcurrent tripping condition and the overcurrent starting delay are met, a protection action outlet of the power-losing condition is detected within 500 ms; when any phase current of the three-phase currents exceeds a fixed value and the direction is in an action area and harmonic waves are not locked, starting delay, enabling the delay to meet the requirement of post action, and enabling the action to select overcurrent alarming or overcurrent opening to be respectively switched on and off.
5. The microcomputer type power distribution automation station terminal based on multi-line measurement and control as set forth in claim 1, wherein: the control module (3) is configured with non-interruption current protection, each circuit is provided with a circuit breaker, when the fault current of the circuit is detected to exceed the fixed value of the non-interruption current, the non-interruption current is locked to protect tripping input, a tripping outlet of the protection is locked, and the circuit breaker cuts off the fault circuit.
6. The microcomputer type power distribution automation station terminal based on multi-line measurement and control as set forth in claim 1, wherein: the control module (3) is configured with automatic disconnection, the automatic disconnection comprises automatic disconnection of voltage out-of-limit and automatic disconnection of frequency out-of-limit, and a three-wire voltage distinguishing mode is adopted for controlling automatic control voltage disconnection locking and opening of a grid point on a power supply.
7. The microcomputer type power distribution automation station terminal based on multi-line measurement and control as set forth in claim 6, wherein: the automatic voltage out-of-limit disconnection comprises the following four functions:
(1) automatic splitting of too low a voltage: when the voltage is lower than or equal to 50% Un, automatically opening the gate after time delay;
(2) automatic splitting of overvoltage: when the voltage is higher than or equal to 135% Un, the switch is automatically opened after time delay;
(3) low voltage automatic splitting: when the voltage is between 50% Un and UL, the brake is automatically opened after the time delay TUL;
(4) high voltage automatic splitting: when the voltage is UH-135%Un, the brake is automatically opened after TUH is delayed;
wherein Un is the on-off public line voltage, UL is the low voltage fixed value, UH is the overvoltage fixed value, TUL is the low voltage time limit, and TUH is the high voltage time limit.
8. The microcomputer type power distribution automation station terminal based on multi-line measurement and control as set forth in claim 6, wherein: the automatic frequency-out-of-limit separation comprises the following three sub-functions:
(1) automatic splitting with too low a frequency: when the frequency is lower than or equal to 47.0Hz and is higher than 44.0Hz, automatically opening the valve;
(2) low frequency automatic splitting: when the frequency is between 47.0Hz and f L, the gate is automatically opened after the time delay TfL;
(3) high frequency automatic splitting: when the frequency is between fH and 55.0Hz, the automatic brake opening is performed after the time delay TfH;
wherein f L is low frequency fixed value, tfL is low frequency time limit, fH is high frequency fixed value, tfH is high frequency time limit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211327776.5A CN115498774B (en) | 2022-10-26 | 2022-10-26 | Microcomputer type distribution automation station terminal based on multi-line measurement and control |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211327776.5A CN115498774B (en) | 2022-10-26 | 2022-10-26 | Microcomputer type distribution automation station terminal based on multi-line measurement and control |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115498774A CN115498774A (en) | 2022-12-20 |
| CN115498774B true CN115498774B (en) | 2023-09-29 |
Family
ID=85115019
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211327776.5A Active CN115498774B (en) | 2022-10-26 | 2022-10-26 | Microcomputer type distribution automation station terminal based on multi-line measurement and control |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115498774B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116540006B (en) * | 2023-07-06 | 2023-10-17 | 国网天津市电力公司滨海供电分公司 | Fault detection device and method for power distribution automation terminal |
| CN117741235B (en) * | 2023-12-18 | 2024-07-12 | 南方电网调峰调频发电有限公司检修试验分公司 | Current signal detection system |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102692571A (en) * | 2012-04-27 | 2012-09-26 | 国电南瑞科技股份有限公司 | Distinguishing method for directional element in phase overcurrent protection of transformer |
| CN105244856A (en) * | 2015-09-29 | 2016-01-13 | 国家电网公司 | Method for preventing distance protection misoperation caused by PT line breakage |
| CN106972465A (en) * | 2017-05-22 | 2017-07-21 | 南京南瑞继保电气有限公司 | A kind of transformer overcurrent protection criterion method and device based on negative -sequence power direction |
| CN107276054A (en) * | 2017-07-24 | 2017-10-20 | 江苏易立电气股份有限公司 | Ultra-high-tension power transmission line complete set of protective apparatus and its guard method |
| CN208723530U (en) * | 2018-08-29 | 2019-04-09 | 珠海市阿普顿电气有限公司 | Intelligent microcomputer protecting controller |
| CN110797978A (en) * | 2019-10-31 | 2020-02-14 | 国网河北省电力有限公司电力科学研究院 | Intelligent station terminal with edge computing capability and fault judgment method |
| CN110988532A (en) * | 2019-11-29 | 2020-04-10 | 广西电网有限责任公司电力科学研究院 | Protection logic test system of distribution automation terminal |
| CN111711276A (en) * | 2020-07-23 | 2020-09-25 | 珠海康晋电气股份有限公司 | Distribution automation intelligence feeder terminal |
| CN112510820A (en) * | 2020-11-11 | 2021-03-16 | 广西电网有限责任公司电力科学研究院 | System for automatic splitting of distributed power supply under 10kV feeder line fault |
-
2022
- 2022-10-26 CN CN202211327776.5A patent/CN115498774B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102692571A (en) * | 2012-04-27 | 2012-09-26 | 国电南瑞科技股份有限公司 | Distinguishing method for directional element in phase overcurrent protection of transformer |
| CN105244856A (en) * | 2015-09-29 | 2016-01-13 | 国家电网公司 | Method for preventing distance protection misoperation caused by PT line breakage |
| CN106972465A (en) * | 2017-05-22 | 2017-07-21 | 南京南瑞继保电气有限公司 | A kind of transformer overcurrent protection criterion method and device based on negative -sequence power direction |
| CN107276054A (en) * | 2017-07-24 | 2017-10-20 | 江苏易立电气股份有限公司 | Ultra-high-tension power transmission line complete set of protective apparatus and its guard method |
| CN208723530U (en) * | 2018-08-29 | 2019-04-09 | 珠海市阿普顿电气有限公司 | Intelligent microcomputer protecting controller |
| CN110797978A (en) * | 2019-10-31 | 2020-02-14 | 国网河北省电力有限公司电力科学研究院 | Intelligent station terminal with edge computing capability and fault judgment method |
| CN110988532A (en) * | 2019-11-29 | 2020-04-10 | 广西电网有限责任公司电力科学研究院 | Protection logic test system of distribution automation terminal |
| CN111711276A (en) * | 2020-07-23 | 2020-09-25 | 珠海康晋电气股份有限公司 | Distribution automation intelligence feeder terminal |
| CN112510820A (en) * | 2020-11-11 | 2021-03-16 | 广西电网有限责任公司电力科学研究院 | System for automatic splitting of distributed power supply under 10kV feeder line fault |
Non-Patent Citations (2)
| Title |
|---|
| 含串补输电线路对继电保护的影响;刘可;杨文丽;汪凤月;罗敏;陈卉;赵金朝;保积秀;;青海电力(第04期);全文 * |
| 采用负序功率方向的变压器过流保护判据探讨;曹孝国 等;继电保护及安全自动装置、励磁和直流系统反事故措施研讨会论文集;第1-7页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115498774A (en) | 2022-12-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN115498774B (en) | Microcomputer type distribution automation station terminal based on multi-line measurement and control | |
| EP3703210B1 (en) | Optical current transformer based starting standby transformer open-phase detection method | |
| CN106199341B (en) | Fault line identification method and device under single-phase fault grounding working condition | |
| CN104779705A (en) | Line protection measurement and control method and device | |
| CN108649532B (en) | Injection type transformer line open-phase protection method and device | |
| CN110224491B (en) | Monitoring device, monitoring method and monitoring system for automatic switch of distributed power distribution network | |
| CN107561408B (en) | Method for improving accuracy rate of small current ground fault line selection | |
| CN110460025B (en) | Quick ring-opening method and device | |
| KR100875127B1 (en) | Multifunctional terminal device for distribution automation and its operation method | |
| CN107706891A (en) | A kind of integrated protection and monitoring device and method for ring main unit | |
| CN113625190B (en) | Adaptive identification and protection method for 110kV line disconnection fault | |
| CN113625189B (en) | 110kV line disconnection protection method for measuring low-voltage side phase voltage of transformer | |
| CN108710040A (en) | Shunt capacitor is protected and monitoring integration method | |
| CN101958579A (en) | Method of treating information loss in centralized protection device of digitalized substation | |
| CN208723530U (en) | Intelligent microcomputer protecting controller | |
| CN207397088U (en) | A kind of universal protection supervisory equipment | |
| CN113466742B (en) | 110kV line self-adaptive disconnection protection method based on transformer low-voltage lateral line voltage | |
| CN201590657U (en) | Microcomputer directional current quick-break bus protection device | |
| CN210016327U (en) | Monitoring device and monitoring system for automatic switch of distributed power distribution network | |
| CN201994647U (en) | Small-current grounding wire selection protection controller | |
| CN209896443U (en) | Mobile intelligent distribution box for oil field high-voltage motor | |
| Chen et al. | Analysis of the Influence of Voltage Recovery Process on Line Selection Device When Single-phase Grounding Fault Is Removed | |
| Wu et al. | Research on fault isolation technology and device development of LVDC system | |
| Zimmerman | Microprocessor-based distribution relay applications | |
| CN204652051U (en) | Route protection measure and control device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |