CN113113900A - Microgrid protection control system, method, equipment and storage medium - Google Patents
Microgrid protection control system, method, equipment and storage medium Download PDFInfo
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- 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
- H02H7/28—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 for meshed systems
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- 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
- G01R31/086—Locating faults in cables, transmission lines, or networks according to type of conductors in power transmission or distribution networks, i.e. with interconnected conductors
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- 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
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- 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
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- 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
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- 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
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/388—Islanding, i.e. disconnection of local power supply from the network
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- 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
- Y04S10/50—Systems or methods supporting the power network operation or management, involving a certain degree of interaction with the load-side end user applications
- Y04S10/52—Outage or fault management, e.g. fault detection or location
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Abstract
The invention provides a micro-grid protection control system, a method, equipment and a storage medium, wherein the system comprises a first detection device, a second detection device, a calculation module, a judgment module and a control module, wherein: the first detection device is arranged on the large power grid side and used for detecting a first voltage and a first current on the large power grid side; the second detection device is arranged on the side of the microgrid and used for detecting a second voltage and a second current on the side of the microgrid; the calculation module is used for obtaining a voltage parameter and/or a current parameter; the judging module is used for judging whether the voltage parameter and/or the current parameter exceed a threshold value; and the control module is used for controlling the on-off state of the public grid-connected point according to the judgment structure of the judgment module. According to the system, the detection devices are arranged on the two sides of the public grid-connected point, so that the states of the large power grid side and the micro power grid side are respectively monitored, the fault detection and the fault positioning are rapidly and accurately carried out, key equipment in the direct current micro power grid is protected, and the rest parts in the system can still run safely and reliably.
Description
Technical Field
The invention relates to the field of internet, in particular to a micro-grid protection control system, method, equipment and storage medium.
Background
The direct-current micro-grid is a micro-grid formed by direct current, is an important component of a future intelligent power distribution and utilization system, and has important significance for promoting energy conservation and emission reduction and realizing sustainable development of energy. Compared with an alternating-current micro-grid, the direct-current micro-grid can more efficiently and reliably receive distributed renewable energy power generation systems such as wind and light, energy storage units, electric vehicles and other direct-current power loads.
At present, for a multi-terminal direct-current power distribution system based on a voltage source type converter, methods such as direct-current sudden change, direct-current power or direct-current power sudden change and the like are used for detecting whether a direct-current fault occurs; a multi-terminal direct-current power distribution system protection scheme is provided, based on an IEC 61850 rapid communication system, a direct-current circuit breaker is matched with a relay to rapidly detect and isolate faults.
Accurate fault location is still one of the key points and difficulties in the research of the protection technology of the direct current microgrid, and especially when a direct current line is short and the midpoint is not grounded, the fault diagnosis is more difficult. The operation control of the microgrid is significantly different from that of the traditional power grid, and the design of a protection strategy for the microgrid faces the following difficulties:
(1) bidirectional short circuit current exists inside the microgrid. Due to the access of a large number of distributed power supplies, the micro-grid is no longer in a single-power radial structure of a traditional power distribution network, so that bidirectional short-circuit current exists in partial lines during short circuit, the difference between the capacity of equivalent power supplies on two sides of a fault is large, and the contribution capacity of the fault current of a weak-end power supply is small.
(2) The difference of short-circuit current of the micro-grid in the grid-connected mode and the island mode is obvious. When the grid is connected, the short-circuit current is mainly provided by a large power grid. When the island is isolated, the short-circuit current is mainly provided by a distributed power supply, and the difference is obvious. And the grounding mode of the microgrid can also influence the distribution condition of the short-circuit current. Therefore, the microgrid protection needs to be able to remove the fault when the short circuit capacity difference is large.
(3) The short-circuit current difference of the distributed power supply is large. Distributed power supplies inside the micro-grid can be divided into an inverter type, an asynchronous type and a synchronous type according to interface types, the difference of the contribution levels of short-circuit currents of the power supplies is large, wherein the short-circuit currents of the inverter power supplies are not more than 2 times of rated current due to the current limiting effect of power electronic devices.
(4) Shorter fault clearing time. Compared with a large power grid, the micro power grid is small in capacity and inertia and comprises various distributed power supplies, and when a fault occurs in the power grid, the fault must be removed more quickly to avoid instability. At the same time, fast response of protection elements and policies is also required in order to prevent the distributed power supply from being taken out of service in the event of a fault.
(5) The topology of the microgrid may change. Due to the requirements of micro-grid operation control and energy management, a distributed power supply, an energy storage unit and a load in the micro-grid can operate off-grid or on-grid, so that the topological structure of the micro-grid is changed.
It is to be noted that the information disclosed in the above background section is only for enhancement of understanding of the background of the present invention and therefore may include information that does not constitute prior art known to a person of ordinary skill in the art.
Disclosure of Invention
The invention aims to provide a micro-grid protection control system, a method, equipment and a storage medium, wherein the micro-grid protection control system is used for monitoring the states of a large power grid side and a micro-grid side respectively by arranging detection devices on two sides of a common grid-connected point, so that fault detection and positioning can be rapidly and accurately carried out, key equipment in a direct-current micro-grid is protected, and the rest parts in the system can still run safely and reliably.
The embodiment of the invention provides a micro-grid protection control system, which comprises a first detection device, a second detection device, a calculation module, a judgment module and a control module, wherein:
the first detection device is arranged on the large power grid side and used for detecting a first voltage and a first current on the large power grid side;
the second detection device is arranged on the side of the microgrid and used for detecting a second voltage and a second current on the side of the microgrid;
the calculation module is used for obtaining a voltage parameter and/or a current parameter according to the first voltage, the first current, the second voltage and the second current;
the judging module is used for judging whether the voltage parameter and/or the current parameter exceed a threshold value;
and the control module is used for controlling the on-off state of the public grid-connected point according to the judgment structure of the judgment module.
According to some examples of the invention, the microgrid protection control system further comprises an energy management module;
the energy management module is used for configuring each operation unit and each controller of the microgrid according to the on-off state of the public grid-connected point.
According to some examples of the invention, the voltage parameter comprises a first voltage magnitude, a first voltage fluctuation value, a second voltage magnitude, and/or a second voltage fluctuation value; and
the current parameter comprises a first current value, a first current frequency, a first current phase sequence, a second current value, a second current frequency and/or a second current phase sequence.
The embodiment of the invention also provides a micro-grid protection control method, which comprises the following steps:
detecting a first voltage and a first current on the large power grid side;
detecting a second voltage and a second current on the microgrid side;
obtaining a voltage parameter and/or a current parameter according to the first voltage, the first current, the second voltage and the second current;
judging whether the voltage parameter and/or the current parameter exceed a threshold value;
if the threshold value is not exceeded, the public grid-connected point is controlled to be in a connected state;
and if the threshold value is exceeded, the public grid-connected point is controlled to be in a disconnected state.
According to some examples of the invention, the determining whether the voltage parameter and/or the current parameter exceeds the threshold value comprises:
obtaining a voltage parameter and/or a current parameter according to the first voltage, the first current, the second voltage and the second current;
the voltage parameter comprises a first voltage amplitude value, a first voltage fluctuation value, a second voltage amplitude value and/or a second voltage fluctuation value;
the current parameter comprises a first current value, a first current frequency, a first current phase sequence, a second current value, a second current frequency and/or a second current phase sequence;
judging whether the first voltage amplitude, the first voltage fluctuation value, the second voltage amplitude, the second voltage fluctuation value, the first current frequency, the first current phase sequence, the second current value, the second current frequency or the second current phase sequence exceeds a correspondingly set threshold value or not;
and if any one parameter of the first voltage amplitude, the first voltage fluctuation value, the second voltage amplitude, the second voltage fluctuation value, the first current frequency, the first current phase sequence, the second current value, the second current frequency or the second current phase sequence exceeds a corresponding set threshold value, judging that the voltage parameter and/or the current parameter exceeds the threshold value.
According to some examples of the invention, the determining whether the voltage parameter and/or the current parameter exceeds the threshold value comprises:
obtaining a voltage parameter and/or a current parameter according to the first voltage, the first current, the second voltage and the second current;
the voltage parameter comprises a first voltage amplitude value, a first voltage fluctuation value, a second voltage amplitude value and/or a second voltage fluctuation value;
the current parameter comprises a first current value, a first current frequency, a first current phase sequence, a second current value, a second current frequency and/or a second current phase sequence;
judging whether the first voltage amplitude, the first voltage fluctuation value, the second voltage amplitude, the second voltage fluctuation value, the first current frequency, the first current phase sequence, the second current value, the second current frequency or the second current phase sequence exceeds a correspondingly set threshold value or not;
if any parameter of the first voltage amplitude, the first voltage fluctuation value, the second voltage amplitude, the second voltage fluctuation value, the first current frequency, the first current phase sequence, the second current value, the second current frequency or the second current phase sequence exceeds the corresponding set threshold value, recording the time t when the parameter exceeds the corresponding set threshold value, and when the time t is greater than a time threshold value, judging that the voltage parameter and/or the current parameter exceeds the threshold value.
According to some examples of the invention, the microgrid protection control method further comprises the steps of:
monitoring the on-off state of a public grid-connected point;
if the public grid-connected point is in a connected state, configuring each operation unit and each control of the microgrid according to a grid-connected operation mode;
and if the public grid-connected point is in a disconnected state, configuring each operation unit and each control of the microgrid according to an island operation mode.
An embodiment of the present invention further provides an order generating device, including:
a processor;
a memory having stored therein executable instructions of the processor;
wherein the processor is configured to perform the steps of the microgrid protection control method via execution of the executable instructions.
An embodiment of the present invention also provides a computer-readable storage medium storing a program, characterized in that the program, when executed, implements the steps of the microgrid protection control method.
According to the micro-grid protection control system, the detection devices are arranged on the two sides of the public grid-connected point and are used for respectively monitoring the states of the large power grid side and the micro-grid side, the system is simple in structure, easy to modularize and easy to expand, fault detection and positioning can be rapidly and accurately carried out, key equipment in the direct-current micro-grid is protected, and the rest parts in the system can still run safely and reliably.
Drawings
Other features, objects, and advantages of the invention will be apparent from the following detailed description of non-limiting embodiments, which proceeds with reference to the accompanying drawings and which is incorporated in and constitutes a part of this specification, illustrating embodiments consistent with the present application and together with the description serve to explain the principles of the application. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.
Fig. 1 is a schematic structural diagram of a microgrid protection control system according to an embodiment of the present invention;
FIG. 2 is a schematic structural diagram of a microgrid according to an embodiment of the present invention;
fig. 3 is a flowchart of a microgrid protection control method according to an embodiment of the present invention;
fig. 4 is a schematic structural diagram of a microgrid protection and control device according to an embodiment of the present invention;
fig. 5 is a schematic structural diagram of a computer-readable storage medium according to an embodiment of the present invention.
Detailed Description
Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
Furthermore, the drawings are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and thus their repetitive description will be omitted. Some of the block diagrams shown in the figures are functional entities and do not necessarily correspond to physically or logically separate entities. These functional entities may be implemented in the form of software, or in one or more hardware modules or integrated circuits, or in different networks and/or processor devices and/or microcontroller devices.
Fig. 1 is a schematic structural diagram of a microgrid protection and control system according to an embodiment of the present invention, and fig. 2 is a schematic structural diagram of a microgrid according to an embodiment of the present invention, which includes a distributed power supply, an energy storage device, an energy conversion device, a load, a monitoring and protection unit, and the like. The microgrid protection control system includes a first detection device M100, a second detection device M200, a calculation module M300, a judgment module M400 and a control module M500, and in an actual application scenario, the first detection device M100 and the second detection device M200 are respectively disposed on two sides of a Common Point of Common Coupling (PCC).
The first detection device M100 is disposed on the large power grid side, and is configured to detect a first voltage and a first current on the large power grid side;
the second detecting device M200 is disposed at the microgrid side and configured to detect a second voltage and a second current at the microgrid side;
the calculation module M300 is configured to obtain a voltage parameter and/or a current parameter according to the first voltage, the first current, the second voltage, and the second current; the voltage parameter may include a first voltage amplitude, a first voltage fluctuation value, a second voltage amplitude and/or a second voltage fluctuation value, and the like;
likewise, the current parameter may comprise a first current value, a first current frequency, a first current phase sequence, a second current value, a second current frequency and/or a second current phase sequence, etc.
The judging module M400 is configured to judge whether the voltage parameter and/or the current parameter exceed a threshold;
the control module M500 is configured to control the on-off state of the public grid-connected point according to the judgment structure of the judgment module.
The direct access of the micro-grid to the large power grid changes the structure and the trend flow direction of the power distribution network, so that the traditional relay protection technology relying on overcurrent time limit coordination is prone to malfunction or failure. According to the micro-grid protection control system, the detection devices are arranged on the two sides of the public grid-connected point and are used for respectively monitoring the states of the large power grid side and the micro-grid side, the system is simple in structure, easy to modularize and easy to expand, fault detection and positioning can be rapidly and accurately carried out, key equipment in the direct-current micro-grid is protected, and the rest parts in the system can still run safely and reliably.
The microgrid protection control system of the present invention may further include an energy management module M600; the energy management module M600 is configured to configure each operation unit and each controller of the microgrid according to the on-off state of the public grid-connected point.
The micro-grid protection has certain particularity, and the micro-grid protection can correctly respond to faults when the micro-grid operates in an isolated island mode and a grid-connected mode. For different branches, different parameters can be configured for each operation unit and each controller of the microgrid according to different connected power sources or load properties, and the parameters are set forth according to the positions or functions of the operation units and the controllers:
public point of Presence (PCC): the method is characterized in that forward delay overcurrent protection is configured (the current inflow bus in the microgrid is positive, the current outflow bus is negative), when a fault occurs in the microgrid system, fault current is provided, protection can effectively act, the fault is removed, the other systems can still be safely and stably connected to the grid to operate, and the operation condition of the microgrid is not influenced; reverse instantaneous overcurrent protection, when a large power grid side breaks down, after a micro-grid detects the fault, a grid-connected switch is instantly tripped, the whole system is switched to an island operation mode by smooth control of a grid-connected operation mode, each system in the micro-grid normally operates, and when the grid-connected detection is normal, the whole system can be switched to grid-connected operation again at any time, so that when the large power grid breaks down, the micro-grid does not provide continuous short-circuit current, the protection judgment of a main grid is influenced, false operation is caused, safe and stable operation in the micro-grid system is also ensured, voltage is not dragged by the main grid, and breakdown is further caused.
BUS (BUS): the bus differential protection is configured, so that when the bus has a short-circuit fault, the bus can be timely and accurately tripped, the bus, the switches carried by the bus, the branch circuits, the power generation equipment and the energy storage equipment carried by the branch circuits are protected, and the load is safe.
Feeder lines with DG branches: the method comprises the steps that over-current instantaneous protection is carried out on reverse power, when a fault occurs in a branch feeder, a relay detects the reverse power and passes a large current, the protection is started instantaneously at the moment, a branch feeder circuit breaker is tripped, a fault branch is cut off, other systems of a micro-grid still run normally, and the overall running mode is unchanged; the forward power overcurrent timing protection (0.5s), when the other branch feeder lines or buses have faults, due to time delay setting, after the corresponding main protection refuses to operate, the main protection can be used as backup protection to trip off the corresponding circuit breaker, cut off the corresponding short-circuit current, and protect the carried equipment from the influence of short-circuit faults.
Distributed power source body (DG): and the differential body is used for protection, and when the DG body has a short-circuit fault, the DG equipment can be quickly cut off from the system in time, so that the stable operation of other systems and the fault equipment are prevented from being further damaged.
Load branch feeder: reverse power overcurrent instantaneous protection is carried out to ensure that when a fault occurs in a load branch feeder line, the fault can be quickly cut off.
LOAD body (LOAD): reverse power overcurrent instantaneous protection, when the short circuit trouble takes place in the load system inside, in time the excision trouble load, avoid the trouble to exist continuously and damage equipment, harm system whole operation safety.
The branch feeder line containing the energy storage system: because the energy storage system can be switched between the charging and discharging working states, the protection configuration scheme of the DG branch feeder line and the LOAD branch feeder line should be integrated, and the protection configuration scheme is configured as follows: reverse power overcurrent transient protection, forward power overcurrent timed protection (0.5 s).
The energy storage system body: differential body protection, reverse power over-current transient protection.
All protection configurations should have dual redundancy settings to prevent protection from being refused to move and not to move, and improve the reliability of protection of the microgrid system. The protection equipment should also be reasonably selected, mechanical, solid, hybrid, on-state loss, on-off speed, on-off capacity.
The protection unit is used for protecting various faults occurring at the downstream of a public gateway point of the microgrid, different protection strategies are adopted by the protection unit, and the topological structure, the grounding mode, the intentional frequent type and the like of the microgrid are comprehensively considered when parameters are configured. Therefore, the protection unit can exert the benefits of the distributed power supply to the maximum extent, the power supply reliability of the micro-grid is improved, and the distributed power supply is not cut off as much as possible under the condition of non-self failure.
As shown in fig. 2, when the microgrid operates in different states, the buses and the connected switches are communicated by the energy management module M600 to update the protection constant values and the action curves in time, and the switches carried by the distributed power supply, the energy storage device, the energy conversion device, the load and the like are communicated by respective rectification devices, so as to form a dynamic and flexible protection function for the microgrid as a whole according to different microgrid operating states, thereby ensuring the safe and stable operation and the fault survival capability of the microgrid system as a whole.
An embodiment of the present invention further provides a microgrid protection control method, and fig. 3 is a flowchart of the microgrid protection control method according to an embodiment of the present invention, which specifically includes the following steps:
s100: detecting a first voltage and a first current on the large power grid side;
detecting a second voltage and a second current on the microgrid side;
s200: obtaining a voltage parameter and/or a current parameter according to the first voltage, the first current, the second voltage and the second current;
s300: judging whether the voltage parameter and/or the current parameter exceed a threshold value;
if the threshold is not exceeded, S410: controlling the public grid-connected point to be in a connected state;
if the threshold is exceeded, S420: and controlling the public grid-connected point to be in a disconnected state.
S300, the step of determining whether the voltage parameter and/or the current parameter exceed the threshold may specifically include the following steps:
obtaining a voltage parameter and/or a current parameter according to the first voltage, the first current, the second voltage and the second current; the voltage parameter comprises a first voltage amplitude value, a first voltage fluctuation value, a second voltage amplitude value and/or a second voltage fluctuation value; the current parameter comprises a first current value, a first current frequency, a first current phase sequence, a second current value, a second current frequency and/or a second current phase sequence;
judging whether the first voltage amplitude, the first voltage fluctuation value, the second voltage amplitude, the second voltage fluctuation value, the first current frequency, the first current phase sequence, the second current value, the second current frequency or the second current phase sequence exceeds a correspondingly set threshold value or not;
and if any one parameter of the first voltage amplitude, the first voltage fluctuation value, the second voltage amplitude, the second voltage fluctuation value, the first current frequency, the first current phase sequence, the second current value, the second current frequency or the second current phase sequence exceeds a corresponding set threshold value, judging that the voltage parameter and/or the current parameter exceeds the threshold value. Different threshold values can be set for different parameters, for example, the threshold value for the first voltage amplitude can be set to 3% -5% of the rated voltage on the large mains side.
S300, determining whether the voltage parameter and/or the current parameter exceeds the threshold value also includes the following steps:
obtaining a voltage parameter and/or a current parameter according to the first voltage, the first current, the second voltage and the second current;
the voltage parameter comprises a first voltage amplitude value, a first voltage fluctuation value, a second voltage amplitude value and/or a second voltage fluctuation value; and
the current parameter comprises a first current value, a first current frequency, a first current phase sequence, a second current value, a second current frequency and/or a second current phase sequence;
judging whether the first voltage amplitude, the first voltage fluctuation value, the second voltage amplitude, the second voltage fluctuation value, the first current frequency, the first current phase sequence, the second current value, the second current frequency or the second current phase sequence exceeds a correspondingly set threshold value or not;
if any parameter of the first voltage amplitude, the first voltage fluctuation value, the second voltage amplitude, the second voltage fluctuation value, the first current frequency, the first current phase sequence, the second current value, the second current frequency or the second current phase sequence exceeds the corresponding set threshold value, recording the time t when the parameter exceeds the corresponding set threshold value, and when the time t is greater than a time threshold value, judging that the voltage parameter and/or the current parameter exceeds the threshold value. The time threshold may be 0.1 seconds or some other value.
The microgrid protection control method can also comprise the following steps:
s500: monitoring the on-off state of a public grid-connected point;
if the public point-of-connection is in a connected state, S610: configuring each operation unit and each control of the microgrid according to a grid-connected operation mode;
if the public point-of-connection is in the disconnected state, S620: and configuring each operation unit and each control of the micro-grid according to the island operation mode.
As described above, because the power sources or loads connected to the branches are different in nature, the operating units and the controllers of the microgrid are configured with different parameters, each branch is provided with two sets of parameter configurations in the grid-connected operating state and the island operating state of the microgrid, and when the state of the public grid-connected point is monitored to be changed, the energy management module M600 can configure the operating units and the controls of the microgrid according to the state of the public grid-connected point.
The microgrid protection control method can switch two different operation states of grid connection and island, parameters under different configured operation modes not only ensure the flexibility and the adaptability of a protection strategy, but also ensure the selectivity, the sensitivity, the rapidity and the accuracy of relay protection, and partition protection of the microgrid can be realized according to the configured parameters.
An electronic device 600 according to this embodiment of the invention is described below with reference to fig. 4. The electronic device 600 shown in fig. 4 is only an example, and should not bring any limitation to the functions and the scope of use of the embodiments of the present invention.
As shown in fig. 4, the electronic device 600 is embodied in the form of a general purpose computing device. The components of the electronic device 600 may include, but are not limited to: at least one processing unit 610, at least one memory unit 620, a bus 630 connecting the different platform components (including the memory unit 620 and the processing unit 610), a display unit 640, etc.
Wherein the storage unit stores program code which can be executed by the processing unit 610 such that the processing unit 610 performs the steps according to various exemplary embodiments of the present invention as described in the above-mentioned method section of the present specification. For example, processing unit 610 may perform the steps as shown in fig. 3.
The storage unit 620 may include readable media in the form of volatile memory units, such as a random access memory unit (RAM)6201 and/or a cache memory unit 6202, and may further include a read-only memory unit (ROM) 6203.
The memory unit 620 may also include a program/utility 6204 having a set (at least one) of program modules 6205, such program modules 6205 including, but not limited to: an operating system, one or more application programs, other program modules, and program data, each of which, or some combination thereof, may comprise an implementation of a network environment.
The electronic device 600 may also communicate with one or more external devices 700 (e.g., keyboard, pointing device, bluetooth device, etc.), with one or more devices that enable a user to interact with the electronic device 600, and/or with any devices (e.g., router, modem, etc.) that enable the electronic device 600 to communicate with one or more other computing devices. Such communication may occur via an input/output (I/O) interface 650. Also, the electronic device 600 may communicate with one or more networks (e.g., a Local Area Network (LAN), a Wide Area Network (WAN), and/or a public network such as the Internet) via the network adapter 660. The network adapter 660 may communicate with other modules of the electronic device 600 via the bus 630. It should be appreciated that although not shown in the figures, other hardware and/or software modules may be used in conjunction with the electronic device 600, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage platforms, to name a few.
The embodiment of the invention also provides a computer-readable storage medium for storing a program, wherein the program is executed to realize the steps of the microgrid protection control method. In some possible embodiments, the various aspects of the invention may also be implemented in the form of a program product comprising program code means for causing a terminal device to carry out the steps according to the various exemplary embodiments of the invention described in the method part above of this description when said program product is run on the terminal device.
Referring to fig. 5, a program product 800 for implementing the above method according to an embodiment of the present invention is described, which may employ a portable compact disc read only memory (CD-ROM) and include program code, and may be run on a terminal device, such as a personal computer. However, the program product of the present invention is not limited in this regard and, in the present document, a readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.
The program product may employ any combination of one or more readable media. The readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the foregoing. More specific examples (a non-exhaustive list) of the readable storage medium include: an electrical connection having one or more wires, a portable disk, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.
A computer readable storage medium may include a propagated data signal with readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated data signal may take many forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A readable storage medium may also be any readable medium that is not a readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. Program code embodied on a readable storage medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.
Program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, C + + or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code may execute entirely on the user's computing device, partly on the user's device, as a stand-alone software package, partly on the user's computing device and partly on a remote computing device, or entirely on the remote computing device or server. In the case of a remote computing device, the remote computing device may be connected to the user computing device through any kind of network, including a Local Area Network (LAN) or a Wide Area Network (WAN), or may be connected to an external computing device (e.g., through the internet using an internet service provider).
In summary, the present invention provides a microgrid protection control system, method, device and storage medium, the system includes a first detection device, a second detection device, a calculation module, a judgment module and a control module, wherein: the first detection device is arranged on the large power grid side and used for detecting a first voltage and a first current on the large power grid side; the second detection device is arranged on the side of the microgrid and used for detecting a second voltage and a second current on the side of the microgrid; the calculation module is used for obtaining a voltage parameter and/or a current parameter; the judging module is used for judging whether the voltage parameter and/or the current parameter exceed a threshold value; and the control module is used for controlling the on-off state of the public grid-connected point according to the judgment structure of the judgment module. According to the micro-grid protection control system, the detection devices are arranged on the two sides of the public grid-connected point and are used for respectively monitoring the states of the large power grid side and the micro-grid side, the system is simple in structure, easy to modularize and easy to expand, fault detection and positioning can be rapidly and accurately carried out, key equipment in a direct-current micro-grid is protected, and the rest parts in the system can still run safely and reliably; the microgrid protection control method can switch two different operation states of grid connection and isolated island, the configured parameters in different operation modes not only ensure the flexibility and adaptability of the protection strategy, but also ensure the selectivity, sensitivity, rapidity and accuracy of relay protection, and the regional protection of the microgrid can be realized according to the configured parameters.
The foregoing is a more detailed description of the invention in connection with specific preferred embodiments and it is not intended that the invention be limited to these specific details. It will be evident to those skilled in the art that the present application is not limited to the details of the foregoing illustrative embodiments, and that the present application may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned. Furthermore, it is obvious that the word "comprising" does not exclude other elements or steps, and the singular does not exclude the plural. A plurality of units or means recited in the apparatus claims may also be implemented by one unit or means in software or hardware. The terms first, second, etc. are used to denote names, but not any particular order.
Claims (9)
1. The utility model provides a little electric wire netting protection control system which characterized in that includes first detection device, second detection device, calculation module, judgement module and control module, wherein:
the first detection device is arranged on the power grid side and used for detecting a first voltage and a first current on the large power grid side;
the second detection device is arranged on the side of the microgrid and used for detecting a second voltage and a second current on the side of the microgrid;
the calculation module is used for obtaining a voltage parameter and/or a current parameter according to the first voltage, the first current, the second voltage and the second current;
the judging module is used for judging whether the voltage parameter and/or the current parameter exceed a threshold value;
and the control module is used for controlling the on-off state of the public grid-connected point according to the judgment structure of the judgment module.
2. The microgrid protection and control system of claim 1, further comprising an energy management module;
the energy management module is used for configuring each operation unit and each controller of the microgrid according to the on-off state of the public grid-connected point.
3. The microgrid protection and control system of claim 1, wherein the voltage parameters include a first voltage magnitude, a first voltage fluctuation value, a second voltage magnitude, and/or a second voltage fluctuation value; and
the current parameter comprises a first current value, a first current frequency, a first current phase sequence, a second current value, a second current frequency and/or a second current phase sequence.
4. A micro-grid protection control method is characterized by comprising the following steps:
detecting a first voltage and a first current on the large power grid side;
detecting a second voltage and a second current on the microgrid side;
obtaining a voltage parameter and/or a current parameter according to the first voltage, the first current, the second voltage and the second current;
judging whether the voltage parameter and/or the current parameter exceed a threshold value;
if the threshold value is not exceeded, the public grid-connected point is controlled to be in a connected state;
and if the threshold value is exceeded, the public grid-connected point is controlled to be in a disconnected state.
5. The microgrid protection control method according to claim 4, characterized in that the step of judging whether the voltage parameter and/or the current parameter exceeds a threshold value comprises the steps of:
obtaining a voltage parameter and/or a current parameter according to the first voltage, the first current, the second voltage and the second current;
the voltage parameter comprises a first voltage amplitude value, a first voltage fluctuation value, a second voltage amplitude value and/or a second voltage fluctuation value;
the current parameter comprises a first current value, a first current frequency, a first current phase sequence, a second current value, a second current frequency and/or a second current phase sequence;
judging whether the first voltage amplitude, the first voltage fluctuation value, the second voltage amplitude, the second voltage fluctuation value, the first current frequency, the first current phase sequence, the second current value, the second current frequency or the second current phase sequence exceeds a correspondingly set threshold value or not;
and if any one parameter of the first voltage amplitude, the first voltage fluctuation value, the second voltage amplitude, the second voltage fluctuation value, the first current frequency, the first current phase sequence, the second current value, the second current frequency or the second current phase sequence exceeds a corresponding set threshold value, judging that the voltage parameter and/or the current parameter exceeds the threshold value.
6. The microgrid protection control method according to claim 4, characterized in that the step of judging whether the voltage parameter and/or the current parameter exceeds a threshold value comprises the steps of:
obtaining a voltage parameter and/or a current parameter according to the first voltage, the first current, the second voltage and the second current;
the voltage parameter comprises a first voltage amplitude value, a first voltage fluctuation value, a second voltage amplitude value and/or a second voltage fluctuation value;
the current parameter comprises a first current value, a first current frequency, a first current phase sequence, a second current value, a second current frequency and/or a second current phase sequence;
judging whether the first voltage amplitude, the first voltage fluctuation value, the second voltage amplitude, the second voltage fluctuation value, the first current frequency, the first current phase sequence, the second current value, the second current frequency or the second current phase sequence exceeds a correspondingly set threshold value or not;
if any parameter of the first voltage amplitude, the first voltage fluctuation value, the second voltage amplitude, the second voltage fluctuation value, the first current frequency, the first current phase sequence, the second current value, the second current frequency or the second current phase sequence exceeds the corresponding set threshold value, recording the time t when the parameter exceeds the corresponding set threshold value, and when the time t is greater than a time threshold value, judging that the voltage parameter and/or the current parameter exceeds the threshold value.
7. The microgrid protection and control method of claim 4, further comprising the steps of:
monitoring the on-off state of a public grid-connected point;
if the public grid-connected point is in a connected state, configuring each operation unit and each control of the microgrid according to a grid-connected operation mode;
and if the public grid-connected point is in a disconnected state, configuring each operation unit and each control of the microgrid according to an island operation mode.
8. A microgrid protection control apparatus, comprising:
a processor;
a memory having stored therein executable instructions of the processor;
wherein the processor is configured to perform the steps of the microgrid protection control method of any of claims 4 to 7 via execution of the executable instructions.
9. A computer-readable storage medium storing a program, wherein the program when executed by a processor implements the steps of the microgrid protection control method of any one of claims 4 to 7.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN114243756A (en) * | 2021-11-16 | 2022-03-25 | 云南电网有限责任公司迪庆供电局 | Control device and method for multiple power generating units in area grid-connected and off-grid mode |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN114243756A (en) * | 2021-11-16 | 2022-03-25 | 云南电网有限责任公司迪庆供电局 | Control device and method for multiple power generating units in area grid-connected and off-grid mode |
| CN114243756B (en) * | 2021-11-16 | 2023-09-15 | 云南电网有限责任公司迪庆供电局 | Regional parallel off-grid multiple power generation unit control device and method thereof |
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