CN112467696A - Power distribution system management device and method - Google Patents

Power distribution system management device and method Download PDF

Info

Publication number
CN112467696A
CN112467696A CN202011122995.0A CN202011122995A CN112467696A CN 112467696 A CN112467696 A CN 112467696A CN 202011122995 A CN202011122995 A CN 202011122995A CN 112467696 A CN112467696 A CN 112467696A
Authority
CN
China
Prior art keywords
power distribution
distribution system
system management
management device
data
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.)
Granted
Application number
CN202011122995.0A
Other languages
Chinese (zh)
Other versions
CN112467696B (en
Inventor
谢剑南
傅佳琪
余成
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ningbo Dajia Xiaojia Network Technology Co ltd
Original Assignee
Ningbo Dajia Xiaojia Network Technology Co ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Ningbo Dajia Xiaojia Network Technology Co ltd filed Critical Ningbo Dajia Xiaojia Network Technology Co ltd
Priority to CN202011122995.0A priority Critical patent/CN112467696B/en
Publication of CN112467696A publication Critical patent/CN112467696A/en
Application granted granted Critical
Publication of CN112467696B publication Critical patent/CN112467696B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • 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
    • H02H7/22—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 for distribution gear, e.g. bus-bar systems; for switching devices
    • 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
    • H02J13/00006—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 information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment
    • H02J13/00016—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 information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment using a wired telecommunication network or a data transmission bus
    • 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
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/001—Methods to deal with contingencies, e.g. abnormalities, faults or failures
    • H02J3/00125—Transmission line or load transient problems, e.g. overvoltage, resonance or self-excitation of inductive loads
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
    • Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
    • Y04S10/00—Systems supporting electrical power generation, transmission or distribution
    • Y04S10/20—Systems supporting electrical power generation, transmission or distribution using protection elements, arrangements or systems
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
    • Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
    • Y04S40/00—Systems for electrical power generation, transmission, distribution or end-user application management characterised by the use of communication or information technologies, or communication or information technology specific aspects supporting them
    • Y04S40/12—Systems for electrical power generation, transmission, distribution or end-user application management characterised by the use of communication or information technologies, or communication or information technology specific aspects supporting them characterised by data transport means between the monitoring, controlling or managing units and monitored, controlled or operated electrical equipment
    • Y04S40/124—Systems for electrical power generation, transmission, distribution or end-user application management characterised by the use of communication or information technologies, or communication or information technology specific aspects supporting them characterised by data transport means between the monitoring, controlling or managing units and monitored, controlled or operated electrical equipment using wired telecommunication networks or data transmission busses

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Remote Monitoring And Control Of Power-Distribution Networks (AREA)

Abstract

The invention discloses a power distribution system management device and a power distribution system management method, wherein the power distribution system management device comprises a main chip, a network module connected with the main chip, a storage module, a signal conditioning module and an on-off detection module; the main chip receives the electrical data of the signal conditioning module and the on-off detection module and caches the electrical data in the storage module; the main chip is in communication connection with the power distribution system management devices and the power distribution system servers on other power distribution cabinets through the network module, receives and/or issues instructions, and uploads the electrical data cached in the storage module to the power distribution system servers. The power distribution system management device and the power distribution system management method provided by the invention can ensure the stability and reliability of the power distribution system, avoid power failure accidents caused by overload or short circuit of the power distribution system, analyze fault points in a short time when the faults occur, greatly improve the maintenance efficiency and reduce the economic loss and safety accident risks caused by power failure maintenance of users.

Description

Power distribution system management device and method
Technical Field
The invention relates to a power distribution system management device and method, and belongs to the technical field of power distribution equipment intellectualization.
Background
At present, overload and short circuit occur frequently in a power distribution system, and a large-area power failure accident can be caused under a serious condition, and great economic loss is caused. The maintenance personnel need to repair the fault in time to restore the power supply whenever a trip occurs.
Overload generally means that a user terminal load is excessively connected to cause that power distribution equipment in a certain power distribution cabinet exceeds an allowable current value, and then a protection device in the power distribution cabinet automatically cuts off a circuit to enable all subordinate power distribution cabinets of the power distribution cabinet to be powered off. If the load current of the low-voltage incoming cabinet exceeds the current set value of overload long time delay on the circuit breaker controller, the protection device on the low-voltage incoming cabinet enters tripping protection countdown, and all outgoing cabinet lines of a next stage are powered off after tripping protection action of the low-voltage incoming cabinet, so that a large amount of money loss is caused to production and life of users. In such a case, the service personnel can confirm with the user that a certain less important outgoing line cabinet is cut off and then the incoming line cabinet breaker is closed to restore the power supply. Or the maintainer sets the current set value of overload long delay on the low-voltage incoming line breaker to be large, but the aging of the transformer is accelerated in such a way, and the processing mode does not meet the safety specification.
The problems of aging or biting by small animals cannot be avoided during long-time operation of the distribution system, and the problems of phase short circuit or ground short circuit of the distribution equipment can be caused. However, the traditional industry can only cut off the short-circuit current by the protection of a high-voltage microcomputer or the protection mechanism of a low-voltage switch. The traditional protection mechanism can only indicate that a fault point occurs at a certain position under the bus line, and cannot give an accurate fault range. If the fault point is accurately found, the short-circuit fault point can be found only by relying on the experience and the technical capability of an electrician for a large amount of time. Generally, troubleshooting of short-circuit fault points needs to be performed line by means of equipment such as a multimeter and the like. Such a method of elimination is very inefficient, and a fault point cannot be located in time, thereby causing a greater economic loss due to an extended power outage time.
Disclosure of Invention
The invention aims to provide a power distribution system management device and a power distribution system management method, which are used for solving the problem of power failure accidents caused by overload or short circuit of a power distribution system in the prior art.
In order to achieve the purpose, the invention is realized by adopting the following technical scheme:
in a first aspect, the invention provides a power distribution system management device, which comprises a main chip, a network module connected with the main chip, a storage module, a signal conditioning module and an on-off detection module;
the main chip receives the electrical data of the signal conditioning module and the on-off detection module and caches the electrical data in the storage module;
the main chip is in communication connection with the power distribution system management devices and the power distribution system servers on other power distribution cabinets through the network module, receives and/or issues instructions, and uploads the electrical data cached in the storage module to the power distribution system servers.
In combination with the first aspect, further, the network module includes a USB serial port, a CAN interface, and an ethernet interface, the USB serial port is in communication connection with an upper computer of the power distribution system management device, the CAN interface is in communication connection with the power distribution system management devices on other power distribution cabinets, and the ethernet interface is in communication connection with the power distribution system server.
Preferably, the network module further comprises an RS485 interface, and the RS485 interface is in communication connection with a dehumidifier of the power distribution system.
Preferably, the CAN interface CAN also receive time service data of a GPS/Beidou positioning receiver.
In combination with the first aspect, further, the input end of the signal conditioning module is connected to a voltage current transformer, and the signal conditioning module conditions and transmits a signal acquired by the voltage current transformer to the main chip.
With reference to the first aspect, further, the on-off detection module includes at least one current limiting circuit and at least one micro optocoupler, the current limiting circuit processes a signal of a target loop into a size that can be detected by the micro optocoupler, and the main chip detects on-off of the target loop through the micro optocoupler.
Preferably, the main chip is internally provided with a high-speed AD unit and a DSP unit, the high-speed AD unit is connected with the output end of the signal conditioning module, the high-speed AD unit converts a circuit signal from an analog quantity to a data quantity, and the DSP unit processes the circuit signal of the data quantity into electrical data convenient for the main chip to process.
Preferably, the memory module includes an EEPROM and an external flash. The EEPROM is used for storing system parameters, user configuration parameters and electric quantity information; and the external flash is used for storing alarm information fault recording data, protection fixed value data and bill of material data.
In a second aspect, the present invention further provides a power distribution system management method, which is implemented by any one of the following methods:
the method a comprises the following steps: the power distribution system management device acquires a three-phase current value and judges whether overload linkage protection is started or not according to the maximum current value;
the method b: the power distribution system management device caches the electrical data, and judges whether to freeze the cached data or not and whether to start the quick-break trip protection or not according to the electrical data in the current circuit.
In combination with the second aspect, further, the method a includes:
the power distribution system management device obtains a three-phase current value, finds a maximum current value I, and judges the magnitude of the maximum current value I and an overload long-delay current setting value I:
if I is larger than or equal to I, the power distribution system management device starts a timer function to time, calculates the trip time T, and compares whether the difference value between the value of the current timer and the value of T is smaller than a set threshold value; if the difference is smaller than the set threshold, starting linkage protection logic; if the difference value is larger than or equal to the set threshold value, continuously acquiring a three-phase current value;
if I is less than I, the timer function is closed, timing is cleared, and the three-phase current value is continuously obtained.
In combination with the second aspect, further, the method b includes:
the power distribution system management device caches the electrical data and judges whether the current electrical quantity meets the quick-break tripping condition:
if the condition of quick-break tripping is met, informing a lower-level power distribution system management device to freeze and cache electrical data, uploading the frozen and cached electrical data to a power distribution system server, and executing tripping operation; after the cutting-off is finished, the power distribution system management device carries out fault information input and wave recording and uploads the fault information to a power distribution system server;
if the quick-break tripping condition is not met but an instruction of freezing the cached electrical data sent by a superior power distribution system management device is received, freezing the cached electrical data and uploading the frozen cached electrical data to a power distribution system server;
and if the quick-break tripping condition is not met and the command for freezing the cached data is not received, continuously and circularly storing subsequent electrical data.
With reference to the second aspect, the method further includes establishing a data model of mutual communication among the power distribution system management devices in the power distribution system, configuring an electrical hierarchy code for each device of the power distribution system, encapsulating the coded information into an ID of a CAN extended frame, and transmitting data of the power distribution system management devices through a data frame carrier, so as to implement data sharing and distribution among the power distribution system management devices.
With reference to the second aspect, further, the calculation formula for calculating the trip time T is as follows:
Figure RE-595040DEST_PATH_IMAGE001
wherein, I represents the maximum value of the three-phase instantaneous current value collected by the power distribution system management device, I represents the overload long delay current setting value, T represents the overload long delay time setting value, and T represents the tripping time of the circuit breaker.
In combination with the second aspect, further, the linkage protection logic includes that according to the priority of subordinate power distribution cabinets set by users, tripping instructions are issued in sequence, and the total load of a main cabinet of the power distribution cabinet is reduced until important lines can be guaranteed not to be powered off.
Compared with the prior art, the invention can at least achieve the following beneficial effects:
the intelligent power distribution cabinet is provided with a main chip, a network module connected with the main chip, a storage module, a signal conditioning module and an on-off detection module, a linkage protection logic is started under the condition of overload of the power distribution cabinet, lower power distribution cabinets are sequentially switched off according to priorities set by users to reduce the total load of the main cabinet, the stability and the reliability of the operation of the main cabinet are ensured, unnecessary power failure accidents are avoided, economic loss caused by power failure is reduced, and safety accident risk caused by power failure is reduced;
the management devices at all levels communicate through the CAN bus of the network module and communicate with the power distribution system server through the Ethernet of the network module, when the circuit has an electrical short-circuit fault, the electrical data at the fault moment is frozen and uploaded to the power distribution system server, and the power distribution system server CAN analyze the fault occurrence condition in a short time, so that the maintenance efficiency is greatly improved, and the economic loss and the safety accident risk caused by power failure maintenance of a user are reduced;
the management devices at all levels communicate through the CAN bus of the network module, so that the wiring cost is low, and the real-time performance and the reliability CAN be ensured.
Drawings
Fig. 1 is a block diagram of a power distribution system management apparatus according to an embodiment of the present invention;
fig. 2 is a schematic application diagram of a power distribution system management apparatus according to an embodiment of the present invention;
fig. 3 is a flowchart of overload linkage protection of a power distribution system management method according to a second embodiment of the present invention;
fig. 4 is a flowchart of short-circuit fault protection of a power distribution system management method according to a second embodiment of the present invention;
fig. 5 is an electrical level coding rule diagram of a power distribution system management method according to a second embodiment of the present invention;
fig. 6 is a CAN extended frame ID allocation diagram of a power distribution system management method according to a second embodiment of the present invention;
fig. 7 is a power distribution structure of a power distribution system management method according to a third embodiment of the present invention;
fig. 8 is a flowchart illustrating an implementation of a circuit system power distribution system server in short-circuit fault protection according to a power distribution system management method according to a third embodiment of the present invention;
fig. 9 is cache data frozen by a power distribution system management apparatus in a power distribution system management method according to a third embodiment of the present invention;
fig. 10 is a visual chart of the cache data frozen by the power distribution system management apparatus in the power distribution system management method according to the third embodiment of the present invention;
fig. 11 is an example of electrical level codes of a power distribution system management device in a power distribution system management method according to a third embodiment of the present invention.
Detailed Description
The invention is further described below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.
In the description of the present invention, the terms "upper end", "bottom", etc. indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of describing the present invention but do not require that the present invention must be patterned and operated in a specific orientation, and thus, should not be construed as limiting the present invention.
The first embodiment is as follows:
as shown in fig. 1, an embodiment of the present invention provides a power distribution system management device, which includes a main chip, a network module connected to the main chip, a storage module, a signal conditioning module, and an on-off detection module;
the main chip receives the electrical data of the signal conditioning module and the on-off detection module and caches the electrical data in the storage module;
the main chip is in communication connection with the power distribution system management devices and the power distribution system servers on other power distribution cabinets through the network module, receives and/or issues instructions, and uploads the electrical data cached in the storage module to the power distribution system servers.
Specifically, the main chip is an ARM architecture single chip with a built-in high-speed AD unit and a built-in DSP unit. The high-speed AD unit is connected with the output end of the signal conditioning module, the high-speed AD unit converts circuit signals from analog quantity to data quantity, and the DSP unit processes the circuit signals of the data quantity into electrical data convenient for the main chip to process. In this embodiment, the main chip has the following model: STM32F407ZGT 6.
The input end of the signal conditioning module is connected with at least one group of voltage and current transformers, and the signal conditioning module conditions and transmits signals collected by the voltage and current transformers to the high-speed AD unit of the main chip.
Specifically, the voltage current transformer includes: the integrated operational amplifier is used for collecting temperature signals and Rogowski coil signals, the miniature voltage transformer is used for collecting voltage sampling signals, the miniature current transformer is used for measuring current sampling signals, and the miniature current transformer is used for collecting protection current sampling signals.
The on-off detection module comprises at least one current limiting circuit and at least one micro optical coupler, the current limiting circuit processes signals of a target loop into the size which can be detected by the micro optical coupler, and the main chip detects the on-off of the target loop through the micro optical coupler.
Specifically, because strong electric switch signals, such as a voltage loss alarm signal and signals of a closing loop and an opening loop are all 110V-220V, the on-off detection of the singlechip on the signals is realized by driving an optocoupler through a current-limiting resistor. Other passive switch signals such as knife switch handcart and other signals directly control the optical coupler to be connected so as to realize the detection of the singlechip on the signals.
The network module comprises a USB serial port, a CAN interface, an Ethernet interface and an RS485 interface, the USB serial port is in communication connection with an upper computer of the power distribution system management device, the CAN interface is in communication connection with the power distribution system management device on other power distribution cabinets, the Ethernet interface is in communication connection with a power distribution system server, and the RS485 interface is in communication connection with a dehumidifier of the power distribution system. It should be noted that the CAN interface of the network module CAN also receive the time service data of the GPS/beidou positioning receiver.
The storage module comprises an EEPROM and an external flash. The EEPROM is used for storing system parameters, user configuration parameters and electric quantity information; the external flash is used for storing alarm information fault recording data, protection fixed value data and bill of material data.
The power distribution system management device is arranged on the power distribution cabinet to realize the monitoring of the whole power distribution system. An application scenario of the power distribution system management device is shown in fig. 2.
Example 2:
the embodiment of the invention provides a power distribution system management method, which is realized by adopting any one of the following methods:
the method a comprises the following steps: the power distribution system management device acquires a three-phase current value and judges whether overload linkage protection is started or not according to the maximum current value;
the method b: the power distribution system management device caches the electrical data, and judges whether to freeze the cached data or not and whether to start the quick-break trip protection or not according to the electrical data in the current circuit.
As shown in fig. 3, the method a includes:
the power distribution system management device obtains a three-phase current value, finds a maximum current value I, and judges the magnitude of the maximum current value I and an overload long-delay current setting value I:
if I is larger than or equal to I, the power distribution system management device starts a timer function to time, calculates the trip time T, and compares whether the difference value between the value of the current timer and the value of T is smaller than a set threshold value; if the difference is smaller than the set threshold, starting linkage protection logic; if the difference value is larger than or equal to the set threshold value, continuously acquiring a three-phase current value;
if I is less than I, the timer function is closed, timing is cleared, and the three-phase current value is continuously obtained.
As shown in fig. 3, the linkage protection logic includes that tripping instructions are sequentially issued according to the priority of the subordinate power distribution cabinets set by users, and the total load of the main cabinet of the power distribution cabinet is reduced until the important lines are ensured not to be powered off.
Specifically, the formula for calculating the trip time T is:
Figure RE-707353DEST_PATH_IMAGE001
wherein, I represents the maximum value of the three-phase instantaneous current value collected by the power distribution system management device, I represents the overload long delay current setting value, T represents the overload long delay time setting value, and T represents the tripping time of the circuit breaker.
As shown in fig. 4, method b includes:
the power distribution system management device caches the electrical data and judges whether the current electrical quantity meets the quick-break tripping condition:
if the condition of quick-break tripping is met, informing a lower-level power distribution system management device to freeze and cache electrical data, uploading the frozen and cached electrical data to a power distribution system server, and executing tripping operation; after the cutting-off is finished, the power distribution system management device carries out fault information input and wave recording and uploads the fault information to a power distribution system server;
if the quick-break tripping condition is not met but an instruction of freezing the cached electrical data sent by a superior power distribution system management device is received, freezing the cached electrical data and uploading the frozen cached electrical data to a power distribution system server;
and if the quick-break tripping condition is not met and the command for freezing the cached data is not received, continuously and circularly storing subsequent electrical data.
In order to realize data synchronization among the management devices of the power distribution system, the method also comprises the steps of establishing a data model of mutual communication among the management devices of the power distribution system, configuring an electrical level code for each device of the power distribution system, packaging coded information into an ID (identity) of a CAN (controller area network) extension frame, and transmitting data of the management devices of the power distribution system through a data frame carrier to realize data sharing and distribution among the management devices of the power distribution system.
The encoding rules are defined as shown in fig. 5. The first number is defined to indicate the management voltage level of the current distribution system management apparatus, where 1 indicates a distribution system of 380 volts, 2 indicates a distribution system of 6 kv, 3 indicates a distribution system of 10kv, and 4 indicates a distribution system of 35 kv. The second digit is defined to represent the type of the cabinet where the current power distribution system management device is located, and the cabinets can be currently classified into 7 types (0 represents an incoming cabinet, 1 represents a line cabinet, 2 represents a contact cabinet, 3 represents a capacitor cabinet, 4 represents a power generation cabinet, 5 represents a transformer cabinet, and 6 represents an isolation cabinet). The third number is defined to represent the superior number of the power distribution system management device. The fourth number represents its own code. The codes of the latter two numbers refer to the numbers of a plurality of power distribution system management devices under the same condition, for example, two outgoing line power distribution system management devices are connected to the back of the same 10-kilovolt incoming line power distribution system management device to respectively manage two transformers, so that the code of the first outgoing line power distribution system management device is 0, the code of the second outgoing line power distribution system management device is 1, and the like.
The ID of the extension frame of the CAN is used to transmit the electrical level code of the device. The extended frame ID has 29 bits, and it is necessary to perform reasonable functional division on the 29 bits and encapsulate the encoded information of the power distribution system management device, as shown in fig. 6 as encapsulation logic.
Specifically, the 28 th bit in the highest bit indicates whether the message has a super priority, since the communication mechanism of the CAN bus is that the minimum priority of preemptively sending the ID is higher. Thus, it is specified that the 28 th bit of the normal message is "1", and the 28 th bit is "0" if a message of particular urgency needs to be sent prior to the normal message. The 27 th-20 th bits of the ID are the meaning of the function code to represent the message, and the function code length of 8 bytes can accommodate 256 message function allocations. Bits 19-16 of the ID indicate the voltage class of the message sender, and the length of 4 bytes can accommodate 16 voltage classes. The 15 th to 12 th bits of the ID represent the type of the power distribution cabinet where the message sender is located, and the length of 4 bytes can accommodate 16 different cabinet types. The 11 th to 6 th bits of the ID represent the equipment number of the upper-level power distribution cabinet of the message sender, and the length of 6 bytes can contain 64 different numbers. Bits 5-0 of the ID indicate the power distribution system management device number of the message sender, and a length of 6 bytes can accommodate 64 different numbers.
Due to the characteristics of CAN bus communication, each distribution system management device CAN initiate communication to the bus at any time and all equipment on the bus CAN receive data sent by any equipment, so that all cabinet distribution system management devices in one set of distribution system CAN acquire data of other distribution system management devices at will, and the technical support of data synchronization is provided for the functions of automatic overload breaking and short-circuit protection.
Example 3:
the present embodiment is based on a specific application scenario of the power distribution system management device provided in embodiment 1 and the power distribution system management method provided in embodiment 2, and the following embodiments are only used to more clearly illustrate the technical solution of the present invention, and the protection scope of the present invention is not limited thereby.
As shown in fig. 7, if the conventional molded case switch with a circuit breaker or an outlet cabinet is used for overload protection, the following situations may occur:
the first scenario is: assuming that the cabinet #1-1-2 is overloaded in the figure and causes the cabinet #1-1 to be also overloaded, the following three situations occur in certain situations:
1. the trip occurs before the trip occurs for #1-1-2,
2. the #1-1 and the #1-1-2 trip at the same time,
3. the #1-1-2 trips before the # 1-1.
It is best seen for the 3 rd case, because the outgoing line cabinet trips in time to avoid tripping the incoming line main cabinet, which causes #1-1-1 to also power down. However, the 1 st and 2 nd situations often occur due to various factors, and particularly, the first situation occurs when the maintainer has no way to know which branch causes the inlet cabinet to trip.
The second scenario is: if neither of the #1-2-1 and #1-2-2 cabinets is overloaded as shown in fig. 7, the loads of the two are added to cause the overload of # 1-2. Under certain conditions, the circuit breakers in the #1-2 cabinet can perform protection actions, so that the #1-2-1 and the #1-2-2 cabinets are powered off. It is also unclear to the service person for this case what causes the trip, and the appearance of this case can confuse the service person.
With the power distribution structure shown in fig. 7, it is difficult to determine the specific location of the short circuit if the conventional line short circuit protection is adopted. Suppose the short circuit occurs in the power distribution system under the flag of the #1-1-2 cabinet, which causes the #1-1-2, #1-1 and G4 cabinets to sense the short circuit condition, so that several conditions are generated:
1, G4 cabinet tripping, and the rest not acting;
tripping #1-1, and leaving the rest to be not operated;
tripping #1-1-2, and leaving the rest to be not operated;
#1-1-2 and #1-1 were actuated, G4 was not actuated;
5 #1-1 with G4 active and #1-1-2 inactive;
g4, #1-1, # 1-1-2.
In case 1, the service man can only know from the fault alarm record on the microcomputer protection of the G4 cabinet that the quick-break protection is generated, but specifically, no knowledge about which line below causes the short-circuit point to occur in the transformation 1, the connection between the #1-1 and the G4, and the distribution system under the #1-1-1 flag. Because of the high possibility, the conventional short-circuit protection method and the conventional maintenance method need to search every possible fault place to fully eliminate the fault. Such a method of elimination is very inefficient, and a fault point cannot be located in time, thereby causing a greater economic loss due to an extended power outage time.
As shown in fig. 3, if overload protection is performed by using the power distribution system management apparatus and method provided by the present invention, the power distribution system management apparatus installed in #1-1 will first obtain the electrical signal of the rogowski coil from the circuit breaker, and obtain the current value currently passing through the rogowski coil, that is, the current value of the three phases and the zero sequence current value currently passing through #1-1 cabinet, through signal processing and calculation. The power distribution system management device takes over the tripping action signal of the circuit breaker at the same time. The power distribution system management devices installed in the #1-1-1 and the #1-1-2 can acquire the current three-phase current and the current zero-sequence current of the cabinet through the corresponding current transformers. The distribution system management device #1-1 monitors the current data at any time, and in this embodiment, the refresh period is set to 20 milliseconds, and a current and time setting value with an overload and a long delay time is preset in the distribution system management device. The current value acquired by the power distribution system management device, the overload long delay current setting value, the overload long delay time setting value and the tripping time of the intelligent circuit breaker meet the following relations:
Figure RE-635995DEST_PATH_IMAGE002
wherein: i represents the maximum value of the ABC three-phase instantaneous current value collected by the power distribution system management device, I represents an overload long delay current setting value, T represents the overload long delay time setting value, and T represents the tripping time of the circuit breaker. Assuming that current A, B, C three-phase currents are respectively 10A, 12A and 15A, namely I =15A, a current setting value I =10A is set, and an overload long delay time setting value T =100 seconds is set, the trip time is calculated to be T =100 seconds, so that the power distribution system management device can control the circuit breaker to break the power failure of the lower stage cabinets #1-1-1 and #1-1-2 of the disconnecting link after 100 seconds if the current is not changed. Rules can be formulated: and the low-voltage inlet line main cabinet power distribution system management device informs the feeder cabinet power distribution system management device under the flag to open a circuit breaker when the low-voltage inlet line main cabinet power distribution system management device is in quick approach trip. For example, when the timer is less than the preset time from trip: and 5 seconds, starting the linkage protection logic. And informing the corresponding power distribution system management devices one by one according to the priority of the lower-level power distribution cabinet to execute circuit breaker breaking operation until the current detected by the #1-1 power distribution system management device is lower than the overload long-delay current setting value.
Specifically, the linkage protection logic is: the #1-1 power distribution system management device firstly detects whether the #1-1-1 power distribution system management device is on line and a breaker is in an 'on' state and a linkage protection function is opened, if one of the conditions is not met, the #1-1-1 power distribution system management device is skipped to continuously judge the #1-1-2 power distribution system management device, if the #1-1-1 power distribution system management device meets the condition, a trip signal is sent to the #1-1-1 power distribution system management device through the CAN bus, and the #1-1-1 power distribution system management device immediately executes a breaker breaking operation after receiving the signal. If the detected current of the #1-1 after the #1-1-1 is switched off is already lower than the setting value i, the protection function plays a role in avoiding larger-range power failure caused by the tripping of the #1-1-1 cabinet breaker by controlling the tripping of the #1-1-1 cabinet breaker. If the #1-1 detects that the current is still larger than the setting value i, the #1-1-2 CAN be continuously controlled to be cut off, or if the timer exceeds T, the #1-1 power distribution system management device CAN control the breaker of the #1-1 to trip (the condition is basically caused by CAN communication failure or unreasonable priority configuration).
It should be noted that, in actual operation, a user needs to configure the priority of the feeder distribution system management device according to his own needs. When the user considers that the power supply of a certain feeder cabinet is the least important (such as office lighting circuit), the intelligent breaking priority of the power distribution system management device of the cabinet is set to be the highest. When the power distribution system management device of the incoming line cabinet monitors that the current overload intelligent breaking condition is met, the power distribution system management device with the highest priority is firstly informed to execute tripping operation, so that the total load of the main cabinet is reduced, and the important line is ensured not to be cut off.
If the power distribution system management device and the method provided by the invention are adopted to carry out over-short circuit protection, firstly, the power distribution system management devices on all the power distribution cabinets adopt the same method to sample voltage and current data at the same sampling frequency and at the same time. Specifically, the voltage and current data are sampled by a high-speed AD unit inside the STM32F407 at a frequency of 64 points per cycle, FFT (fast fourier transform) is performed for 64 points per sample to obtain the real and imaginary components of the fundamental wave, and the amplitude and phase of the fundamental wave can be obtained by further calculation. Therefore, the distribution system management device can recognize the change of the electric quantity of about 20ms at the maximum. The power distribution system management device is set to record the variation value of the electric quantity of about 1 second in a circulating way every 20ms, namely all the electric quantity instantaneous values (including three-phase voltage, three-phase current and zero-sequence current) of the past 50 times are cached.
As shown in fig. 4, the power distribution system management apparatus determines whether the electrical data in the current circuit satisfies the quick-break trip condition: if the condition of quick-break tripping is met, an instruction is given to a lower-level power distribution system management device: freezing the cached electrical data, uploading the frozen cached electrical data to a power distribution system server, and executing a trip operation; after the cutting-off is finished, the power distribution system management device carries out fault information input and wave recording and uploads the fault information to a power distribution system server; if the quick-break tripping condition is not met but an instruction of freezing the cached electrical data sent by a superior power distribution system management device is received, freezing the cached electrical data and uploading the frozen electrical data to a power distribution system server; and if the quick-break tripping condition is not met and the command for freezing the cached data is not received, continuously and circularly storing subsequent electrical data.
As shown in FIG. 8, the power distribution system clothesThe server will always monitor the management device of the power distribution system without reporting the information of the quick break. If the information of the 'quick-break protection' is reported by the power distribution system management device, the reported level of the power distribution system management device is judged firstly. If the fault is reported by the distribution system management device of the 380V feeder cabinet, the short-circuit fault is directly located, so that the distribution system server only needs to acquire the reported information of the distribution system management device of the feeder cabinet to inform the user of the position of the fault point. If the data is reported by the 380V incoming line power distribution system management device, the cache data of all feeder cabinet power distribution system management devices at the lower level of the incoming line power distribution system management device needs to be extracted, and the corresponding maximum value needs to be extracted. The power distribution system server is used for buffering the maximum current value I in the datamaxComparing with the quick-break constant value Id set by the corresponding power distribution system management device, if ImaxIf the Id is larger than the preset value, the power distribution system management device and the lower power distribution system management device are determined to have short-circuit faults. If ImaxIf the number of the cache data provided by all the lower-level feeder cabinet power distribution system management devices of one 380V incoming line power distribution system management device shows no short-circuit fault, the fault is judged to be generated at the cable connection position. And by analogy, the fault occurrence position can be positioned by recursing downwards layer by layer from the power distribution system management device which generates the quick break.
Fig. 9 shows data frozen by a 380V low-voltage feeder cabinet power distribution system management device. The data span from 0 th second to 0.98 th second for 50 groups of data, with 0.02 second interval between each group of data. Three-phase voltage (U) under normal condition can be judged from frozen dataa，Ub，Uc) All are 220V, three-phase current (I)a，Ib，Ic) Are all 5A. When three phases are short-circuited suddenly, the current value suddenly changes to be more than 100A and the voltage is also reduced to be between 130V and 150V, and then the quick-break protection of the upper-level low-voltage incoming line cabinet is triggered, so that the cabinet is also powered off, the voltage is further reduced to be 0V, and the short-circuit current disappears randomly. The visual chart shown in fig. 10 can determine a short circuit from frozen dataProtection occurs at 0.9s and at 0.92 s.
In order to realize data synchronization among the power distribution system management devices, a model for mutual communication among the power distribution system management devices in the power distribution system needs to be established, codes are configured for each power distribution system management device, and a transmission protocol is formulated through a CAN (controller area network) bus to realize data intercommunication among the power distribution system management devices.
As shown in fig. 5, a distribution structure is assumed to have a structure of a distribution room, in which a 10kv voltage is fed into two 10kv lines, and then the voltage is changed to 380v by connecting a transformer to each of the lines. And then the back of the first transformer is connected with two low-voltage incoming lines, and the back of each of the two low-voltage incoming line cabinets is connected with two low-voltage outgoing lines. The second transformer is connected with a voltage incoming line and then two low-voltage outgoing lines. Each device is coded by adopting the coding mode of the invention: the voltage class of the 10KV high-voltage isolation cabinet power distribution system management device is 10Kv so that the first number is 3, then the second number is 6 according to the type of a cabinet, the upper-level number can adopt a default value of 0, and the device is the first device of the type of the hierarchy so that the fourth number is 0. And by analogy, all the power distribution system management device codes can be determined. The complete power distribution system management device code is shown in fig. 11.
Due to the characteristics of CAN bus communication, each distribution system management device CAN initiate communication to the bus at any time and all equipment on the bus CAN receive data sent by any equipment, so that all cabinet distribution system management devices in one set of distribution system CAN acquire data of other distribution system management devices at will, and the technical support of data synchronization is provided for the functions of automatic overload breaking and short-circuit protection.
The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.

Claims (10)

1. A power distribution system management device is arranged on a power distribution cabinet and is characterized by comprising a main chip, a network module, a storage module, a signal conditioning module and an on-off detection module, wherein the network module, the storage module, the signal conditioning module and the on-off detection module are connected with the main chip;
the main chip receives the electrical data of the signal conditioning module and the on-off detection module and caches the electrical data in the storage module;
the main chip is in communication connection with the power distribution system management devices and the power distribution system servers on other power distribution cabinets through the network module, receives and/or issues instructions, and uploads the electrical data cached in the storage module to the power distribution system servers.
2. The power distribution system management device according to claim 1, wherein the network module comprises a USB serial port, a CAN interface and an ethernet interface, the USB serial port is in communication connection with an upper computer of the power distribution system management device, the CAN interface is in communication connection with power distribution system management devices on other power distribution cabinets, and the ethernet interface is in communication connection with a power distribution system server.
3. The power distribution system management device according to claim 1, wherein a voltage current transformer is connected to an input end of the signal conditioning module, and the signal conditioning module conditions and transmits a signal collected by the voltage current transformer to the main chip.
4. The power distribution system management device according to claim 1, wherein the on-off detection module comprises at least one current limiting circuit and at least one micro optical coupler, the current limiting circuit processes a signal of a target loop into a size which can be detected by the micro optical coupler, and the main chip detects on-off of the target loop through the micro optical coupler.
5. A power distribution system management method is characterized by being realized by adopting any one of the following methods:
the method a comprises the following steps: the power distribution system management device acquires a three-phase current value and judges whether overload linkage protection is started or not according to the maximum current value;
the method b: the power distribution system management device caches the electrical data, and judges whether to freeze the cached data or not and whether to start the quick-break trip protection or not according to the electrical data in the current circuit.
6. The power distribution system management method of claim 5, wherein method a comprises:
the power distribution system management device obtains a three-phase current value, finds a maximum current value I, and judges the magnitude of the maximum current value I and an overload long-delay current setting value I:
if I is larger than or equal to I, the power distribution system management device starts a timer function to time, calculates the trip time T, and compares whether the difference value between the value of the current timer and the value of T is smaller than a set threshold value; if the difference is smaller than the set threshold, starting linkage protection logic; if the difference value is larger than or equal to the set threshold value, continuously acquiring a three-phase current value;
if I is less than I, the timer function is closed, timing is cleared, and the three-phase current value is continuously obtained.
7. The power distribution system management method of claim 5, wherein method b comprises:
the power distribution system management device caches the electrical data and judges whether the current electrical quantity meets the quick-break tripping condition:
if the condition of quick-break tripping is met, informing a lower-level power distribution system management device to freeze and cache electrical data, uploading the frozen and cached electrical data to a power distribution system server, and executing tripping operation; after the cutting-off is finished, the power distribution system management device carries out fault information input and wave recording and uploads the fault information to a power distribution system server;
if the quick-break tripping condition is not met but an instruction of freezing the cached electrical data sent by a superior power distribution system management device is received, freezing the cached electrical data and uploading the frozen cached electrical data to a power distribution system server;
and if the quick-break tripping condition is not met and the command for freezing the cached data is not received, continuously and circularly storing subsequent electrical data.
8. The power distribution system management method according to claim 5, further comprising establishing a data model of mutual communication of the power distribution system management devices in the power distribution system, configuring an electrical level code for each device of the power distribution system, encapsulating the code information into an ID of a CAN extended frame, and transmitting data of the power distribution system management devices through a data frame carrier to realize data sharing and distribution among the power distribution system management devices.
9. The power distribution system management method of claim 6 wherein the trip time T is calculated by the formula:
Figure 299001DEST_PATH_IMAGE001
wherein, I represents the maximum value of the three-phase instantaneous current value collected by the power distribution system management device, I represents the overload long delay current setting value, T represents the overload long delay time setting value, and T represents the tripping time of the circuit breaker.
10. The power distribution system management method according to claim 6, wherein the linkage protection logic comprises that tripping instructions are sequentially issued according to the priority of the subordinate power distribution cabinets set by the user, and the total load of the main cabinets of the power distribution cabinets is reduced until the important lines can be ensured not to be powered off.
CN202011122995.0A 2020-10-20 2020-10-20 Power distribution system management device and method Active CN112467696B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202011122995.0A CN112467696B (en) 2020-10-20 2020-10-20 Power distribution system management device and method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202011122995.0A CN112467696B (en) 2020-10-20 2020-10-20 Power distribution system management device and method

Publications (2)

Publication Number Publication Date
CN112467696A true CN112467696A (en) 2021-03-09
CN112467696B CN112467696B (en) 2023-10-24

Family

ID=74833843

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202011122995.0A Active CN112467696B (en) 2020-10-20 2020-10-20 Power distribution system management device and method

Country Status (1)

Country Link
CN (1) CN112467696B (en)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105449865A (en) * 2015-12-17 2016-03-30 南京因泰莱电器股份有限公司 Intelligent (feeder terminal unit) FTU used for fault positioning and isolating for distribution network
CN105743082A (en) * 2016-04-27 2016-07-06 武汉大学 Overload switching device suitable for DC power distribution system
CN110412416A (en) * 2019-07-04 2019-11-05 天津市中力神盾电子科技有限公司 Distribution line fault recording method and system

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105449865A (en) * 2015-12-17 2016-03-30 南京因泰莱电器股份有限公司 Intelligent (feeder terminal unit) FTU used for fault positioning and isolating for distribution network
CN105743082A (en) * 2016-04-27 2016-07-06 武汉大学 Overload switching device suitable for DC power distribution system
CN110412416A (en) * 2019-07-04 2019-11-05 天津市中力神盾电子科技有限公司 Distribution line fault recording method and system

Also Published As

Publication number Publication date
CN112467696B (en) 2023-10-24

Similar Documents

Publication Publication Date Title
CN102957208B (en) Intelligent monitoring device of power distribution transformer and control method thereof
CN201444191U (en) Direct-current power supply online monitoring system
CN107611945B (en) Equipment state sensing type 110kV line protection system and implementation method
CN201699481U (en) Intelligent controller of 10-20kV section switch
CN110794299A (en) Fault online monitoring method and system of circuit breaker
CN111049112B (en) Automatic fault isolation and self-healing control system and method for 10kV looped network distribution line
CN108092248A (en) A kind of intelligent distributed feeder line fault of distribution network quickly cuts off shielding system and its method
CN108233345A (en) A kind of intelligent distributed feeder line fault of distribution network quickly cuts off partition method
CN114256819B (en) Terminal-based self-healing control method for platform area
CN201274417Y (en) Locking remote self-start apparatus for electric grid
CN106058832B (en) A kind of implementation method quickly isolated on the spot
CN112467696A (en) Power distribution system management device and method
CN204012933U (en) Distribution automation detection and control terminal
CN116317132A (en) Automatic switching-on and switching-off device based on current feedback
CN117060569A (en) Control method and control system for transformer substation
CN113541109B (en) Feeder fault processing system and method based on power wireless private network
CN201860172U (en) Automatic looped network type distribution network based on reclosers
CN201887540U (en) 10-20kV dropout fuse intelligent control device
CN112751421A (en) Digital computing enhanced high-reliability low-voltage power distribution safety monitoring system
CN212008841U (en) Fault on-line monitoring system of circuit breaker
CN102280932A (en) Intelligent control device of high-voltage section switch
CN108508829A (en) Crush-cutting machine real time and on line monitoring system is crossed by a kind of small power station based on mobile Internet
CN201846133U (en) Intelligent control device of 10KV-20KVcable ring main unit
CN104297679A (en) Early warning method of breaker tripping messages
CN215870906U (en) Digital computing enhanced high-reliability low-voltage power distribution safety monitoring system

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