CN114221376B - Regional parallel-to-off-network response control method and system - Google Patents

Regional parallel-to-off-network response control method and system Download PDF

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CN114221376B
CN114221376B CN202111356675.6A CN202111356675A CN114221376B CN 114221376 B CN114221376 B CN 114221376B CN 202111356675 A CN202111356675 A CN 202111356675A CN 114221376 B CN114221376 B CN 114221376B
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power
load
power generation
current
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CN114221376A (en
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张敏
杨金东
吴万军
刘永礼
任宪利
李凤龙
李朋
张智
和志全
聂跃昆
李�瑞
黄天喜
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Diqing Power Supply Bureau of Yunnan Power Grid Co Ltd
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Diqing Power Supply Bureau of Yunnan Power Grid Co Ltd
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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
    • H02J3/381—Dispersed generators
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J13/00—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
    • H02J13/00002—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by monitoring
    • 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
    • H02J13/00007—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 the power network as support for the transmission
    • 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
    • H02J3/12—Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load
    • H02J3/14—Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load by switching loads on to, or off from, network, e.g. progressively balanced loading
    • H02J3/144—Demand-response operation of the power transmission or distribution network
    • 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
    • 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
    • H02J3/46—Controlling of the sharing of output between the generators, converters, or transformers
    • H02J3/466—Scheduling the operation of the generators, e.g. connecting or disconnecting generators to meet a given demand
    • 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
    • H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
    • H02J2300/20—The dispersed energy generation being of renewable origin
    • 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
    • H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
    • H02J2300/20—The dispersed energy generation being of renewable origin
    • H02J2300/22—The renewable source being solar energy
    • H02J2300/24—The renewable source being solar energy of photovoltaic origin
    • 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
    • H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
    • H02J2300/20—The dispersed energy generation being of renewable origin
    • H02J2300/28—The renewable source being wind energy
    • 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
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
    • Y02B70/30—Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
    • Y02B70/3225—Demand response systems, e.g. load shedding, peak shaving
    • 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
    • Y04S20/00—Management or operation of end-user stationary applications or the last stages of power distribution; Controlling, monitoring or operating thereof
    • Y04S20/20—End-user application control systems
    • Y04S20/222—Demand response systems, e.g. load shedding, peak shaving
    • 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
    • Y04S40/121—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 the power network as support for the transmission

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  • Supply And Distribution Of Alternating Current (AREA)

Abstract

The application provides a regional on-line and off-line response control method and a regional on-line and off-line response control system, which are implemented by initializing equipment in an off-line region; monitoring and separating data information of a power generation unit and load equipment in the network area, determining the magnitude relation between the load power and the power generation power, and controlling the power generation unit to reduce the power generation power or turn off the load equipment in a time-sharing manner according to the magnitude relation between the load power and the power generation power when separating from the network; and when grid connection is performed, determining a control method for inputting the power generation unit and the load equipment according to a monitoring analysis result in an off-grid state. The power grid voltage stabilizing method has the advantages that the power grid voltage stabilizing method has high quick response and high accuracy, reduces impact of the distributed power generation system on the power grid, guarantees safe and stable operation of loads in the power distribution network, and solves the problem that a load protection device generally needs to set certain time delay to avoid short-circuit fault influence and cannot adapt to the construction requirements of a new-generation intelligent power grid.

Description

Regional parallel-to-off-network response control method and system
Technical Field
The application relates to the technical field of regional off-grid, in particular to a regional off-grid response control method and system.
Background
With the rapid development of renewable energy power generation technology, energy storage technology and load control technology in recent years, a large number of power electronic equipment such as distributed renewable energy power generation and the like are connected into a 400V low-voltage distribution network to form a renewable energy micro-grid system, and the micro-grid is required to have a parallel/off-grid dual-mode operation function in order to reduce loss caused by power failure and ensure the requirement of important load power supply reliability. In addition, with technological development and large-scale distributed power access to the power distribution network, the power flow of the power grid changes, the load structure also tends to be complicated and developed, and a large amount of capacitive load and inductive load are mainly accessed to the low-voltage power distribution network. The load in the low-voltage distribution network can be subdivided into three types, namely a capacitive load, an inductive load and a resistive load, and the three types respectively have different load characteristics. In the grid-connected mode, the micro-grid can basically keep the voltage and the frequency of the grid stable due to the clamping effect of the main grid, and ensure the stable operation of the load.
When the system runs off the network, the system breaks away from the main power grid clamp, the load is supported independently to run, and the unstable property of the power supply voltage and the frequency generated in the micro power grid area can damage electric equipment. Various load devices connected to the micro-grid in the low-voltage distribution network do not have the real-time sensing of the change condition of the grid, and the voltage instability of the micro-grid can be caused when the load is rapidly put in and cut out. For example, when the power consumption is high, a large amount of load equipment is put into a micro-grid to cause the voltage drop of the micro-grid, and when the distributed power supply and the energy storage system in the micro-grid cannot support the voltage stabilization of the system, load-cutting measures are adopted to ensure the safety of the system in order to prevent the occurrence of the conditions such as the damage of the electrical equipment.
The existing load equipment protection device mainly relies on passive detection of power distribution network over/under voltage, over/under frequency and other power change conditions to determine whether protection action occurs. The passive method is to define the limits of over/under frequency and over/under voltage according to experience, and is a trade-off between sensitivity and reliability, and often the detection blind area and the false action area coexist. In addition, in order to avoid short-circuit fault influence, a load protection device generally needs to set certain time delay, and cannot adapt to the construction requirements of a new generation of intelligent power grid.
Disclosure of Invention
The utility model provides a regional parallel off-grid response control method and system, the method and system is based on the intelligent micro-grid parallel/off-grid multi-load response controller control scheme of carrier communication load hierarchical management, instruction data control, power prediction adjustment and automatic load switching, has the capability of quick response and high accuracy, stabilizes the power grid voltage, reduces the impact of a distributed power generation system on the power grid, ensures safe and stable operation of the load in the power distribution network, and solves the problems that a load protection device generally needs to set certain delay to avoid short circuit fault influence and cannot adapt to the construction requirements of a new generation intelligent power grid.
In a first aspect, the present application provides an area and off-network response control method, applied to an area and off-network response controller, where the controller includes: the device comprises a controller module, a multi-interface communication module, a carrier receiving module, a short circuit monitoring module, a voltage sensor, n current sensors, a contactor driving module and n contactors;
the input end of the contactor is connected with the micro-grid and a voltage sensor which is installed in parallel on the micro-grid, and the output end of the contactor is connected with the current sensor in series and is connected with m power generation units and h load devices, wherein n=m+h, and m and h are integers which are larger than or equal to 1;
the current sensor data outputs are all connected with a common data line; the Ad end of the public data line is connected with the data input end of the short circuit monitoring module, and the data output end of the short circuit monitoring module is connected with the data input end of the controller; the controller module is configured to collect data of the current sensor, short circuit states of the load device and the power generation unit, and collect the voltage sensor data;
the contactor control ends are correspondingly connected with n paths of output ends of the contactor driving module, and the data input end of the contactor driving module is connected with the data output end of the controller module; the data output end of the controller module controls the connection and disconnection of the contactor through the contactor driving module;
The contactor driving module further comprises a locking control end, wherein the locking control end is connected with the locking control end of the short circuit monitoring module, when any one of m power generation units or any one of h load devices is in fault short circuit, the associated contactor can be disconnected with a power grid, the locking control end in the associated monitoring module outputs fault state level, and the locking control end in the contactor driving module is locked; when the short circuit monitoring module monitors fault elimination, a locking control end of the short circuit monitoring module releases a locking state level;
the signal input end of the carrier receiving module is connected with a power grid, and the data analysis output end of the carrier receiving module is connected with the data input end of the controller module; the multi-interface communication module comprises m communication interfaces, and the communication interfaces are connected with the communication interfaces of the power generation unit through communication wires; the data output end of the communication module is connected with the communication input and output end of the controller module; the controller module is further configured to read power generation unit data in real time;
the regional parallel-to-off-network response control method comprises the following steps:
Step one, initializing setting, including setting type parameters of power generation equipment;
step two, the current direction is judged by monitoring the power generation unit and the load current in the analysis area, and the step two comprises the following steps:
the regional off-grid response controller monitors load power and power generation power of the power generation unit in real time through a current sensor and a voltage sensor so as to obtain a current direction;
when the controller calculates that the sum of the power generation unit and the load current is positive, the controller responds to the load equipment under the controller to consume micro-grid power for the region and off-grid, so that the load power is larger than the power generation power;
when the controller calculates that the sum of the power generation unit and the load current is negative, the power is released to the power grid for regional and off-grid response to the power generation of the power generation unit under the controller, so that the power generation power is larger than the load power;
when the controller calculates that the sum of the power generation unit and the load current is zero, the power generation power of the power generation unit is equal to the power consumption of the load equipment under the regional and off-grid response controller, so that the power generation power is equal to the load power;
predicting load shedding of load equipment and power increase and decrease of power of a power generation unit at the occurrence moment of the analysis grid;
and step four, controlling load shedding at off-grid occurrence time, which comprises the following steps:
When the regional off-grid response controller judges that off-grid occurs, the load equipment is turned off according to the prediction time sharing;
when the time-sharing control is closed to a certain load device, the controller calculates the sum i of the power generation units and the load current in the area f Less than or equal to the current threshold i min When the controller pauses the closing of the subsequent load equipment;
when the regional parallel off-grid response controller calculates to obtain the sum i of the power generation units and the load current in the region f Greater than the current threshold i min When the load power is the same as the load power, the controller turns off the load power minimum equipment at the current moment;
step five, controlling input and load equipment of a power generation unit when grid connection occurs, comprising the following steps:
the regional parallel off-grid response controller monitors the sum i of the output current and the load current of the power generation unit under the off-grid state f When the load is greater than 0, responding the load in the controller to the regional and off-grid of the micro-gridSupplying power, and when judging grid connection permission, responding and controlling a grid connection method by the regional grid connection response controller;
the regional parallel off-grid response controller monitors the sum i of the output current and the load current of the power generation unit f And when the grid connection allowance is judged, the regional grid connection response controller responds to and controls the grid connection method.
Optionally, the initializing the setting includes:
setting the string type, grid-connected type, capacity, quantity and distance between the photovoltaic power generation equipment and grid-connected points;
setting the single-machine capacity and the number of the wind power generation equipment;
the load sensitivity, the capacity, the resistance and the power of the load equipment are set.
Optionally, the initializing the setting further includes:
dividing each hour into 4 time periods in 15 minutes, and initially setting unit generation power and voltage change coefficient in each time period
Figure BDA0003357517550000031
The new voltage change coefficient of unit power generation is iterated from the learning with the increase of the data volume
Figure BDA0003357517550000032
Optionally, the step of monitoring the power generation unit and the load current in the analysis area to determine the current direction further includes:
the controller module reads current data output by all the power generation units at the current moment and consumed current of the load equipment;
summing current data to obtain-i pz ＝(-i p1 )+(-i p2 )+……(-i pm ) Current, where i p1 Outputting current for the 1 st power generation unit; i.e p2 Outputting current for the 2 nd generating unit; i.e pm For the mth power generation unitCurrent is discharged; i.e pz Outputting the sum of the currents for all the power generation units;
summing up the consumption currents to obtain i sz ＝i s1 +i s2 +……i sh A current; wherein i is s1 Current is consumed for the 1 st load; i.e s2 Current is consumed for the 2 nd load; i.e sh Current is consumed for the h stage load; i.e sz The sum of the current consumption for all loads; i.e f The total output current of the power generation unit is the total output current of the power generation unit during off-grid operation;
summing the output of the power generation unit with the current i pz Summing the consumption current i with the load device sz And summing to obtain the total current i in the region zn ＝-i zp +i zs 。
Optionally, in the step of predicting load shedding of the load device and power increasing/decreasing of the power generation unit at the occurrence time of the analysis grid, when the generated power is greater than the load power, the method further includes:
when the current monitored by the regional grid-connected and off-grid response controller is negative in the grid-connected state, the controller module performs pre-analysis on the working power and the state of the multiple power generation unit according to the current moment and the historical data in the grid-connected working state so as to analyze the voltage change in different time periods and the coefficient of the unit power generation power
Figure BDA0003357517550000033
Wherein alpha is the coefficient of voltage change and generated power in different time periods;
and respectively find out the maximum value p of the historical contemporaneous power by taking 15 minutes as a period max ＝max(p t1 ,p t2 …p t15 ) Minimum voltage U min ＝min(u t1 ,u t2 …u t15 ) And the highest voltage U max ＝max(u t1 ,u t2 …u t15 ) The method comprises the steps of carrying out a first treatment on the surface of the Wherein u is t1 A 1 st minute voltage that is a 15 th minute period of historical synchronization; u (u) t2 2 nd minute voltage for 15 th minute period of history synchronization; u (u) t15 15 th minute voltage, which is a 15 th minute period of historical synchronization; p is p t1 1 st minute power for 15 minute period of history synchronization; p is p t2 For 15 minutes of history synchronization2 minutes power; p is p t15 15 th minute power for 15 th minute period of historical synchronization; i.e max Maximum current in 15 minutes period for historical synchronization; p is p max Maximum power within 15 minutes of the history synchronization; u (U) min Minimum voltage within 15 minutes period for the contemporaneous history; u (U) max Maximum voltage within 15 minutes period for historical synchronization;
calculating maximum load
Figure BDA0003357517550000034
And minimum load->
Figure BDA0003357517550000035
As the internet current under the minimum load condition;
the controller module reads the output currents i of all the generating units at the current moment p1 ……i pm And sum the current i pz ；
When i min ≤i pz ≤i max When the current i is summed pz Subtracting the on-line current to obtain the output current i of the power generation unit at the off-line moment of the micro-grid f ＝i pz -i min Obtaining the ratio of the summation current of the generating units at the current moment
Figure BDA0003357517550000036
According to the ratio i of the currents fn Respectively carrying out product operation with the output current of each power generation unit to obtain the output current of each power generation unit, wherein i is as follows min Minimum current within 15 minutes of history synchronization; i.e fn The ratio of the total output current of the power generation unit during off-grid operation to the total output current of the power generation unit during grid connection is the ratio; i.e f The total output current of the power generation unit is the total output current of the power generation unit during off-grid operation;
And establishing a protocol code of the power generation unit corresponding to the power-off or power-reduction output, and sending the power-reduction protocol code to the multiple power generation unit through the communication module according to the analysis result by the controller module when off-grid operation occurs.
Optionally, in the step of predicting load shedding of the load device and power increasing and decreasing of the power generation unit at the occurrence time of the analysis grid, when the load power is greater than the power generation power, the method further includes:
load shedding of load equipment in the regional off-grid response controller is realized, so that the power generation power of the power generation unit and the load consumption power are approximately balanced, and the load of the micro-grid is reduced;
in the grid-connected working state, the regional grid-connected and off-grid response controller analyzes according to historical data and the power consumption condition of the load equipment of S1 and S2 … … Sh at the moment;
sequencing the S1, S2 … … Sh load devices from large to small in power consumption at the moment, and sequencing the S1, S2 … … Sh devices from large to small in power consumption at the future 24-hour time;
the working state and power of each load device change along with the change of time within the future 24 hours, so that the off-line load device is firstly eliminated by the following formula:
processDate(PS1、PS2……PSh，PShState，m)；
the load equipment of the S1 and S2 … … Sn at any moment is provided with the following power consumption load shedding sequential function from large to small:
sort(processDate(PS1、PS2……PSn，PSnState，m)，'descend')；
Therefore, the load shedding sequence of the S1 and S2 … … Sh load equipment is adjusted in real time, so that the voltage of the micro-grid is prevented from greatly fluctuating;
wherein S1 is the 1 st load, S2 is the 2 nd load, sh is the h load, h is an integer more than or equal to 1; PS1 is the load power of the 1 st load at a certain moment, PS2 is the load power of the 2 nd load at a certain moment, and PSm is the load power of the m-th load at a certain moment; the sort is a sort function at a certain moment; processDate is a function of screening out off-line status load devices; PShState is the state of the load equipment, and h is the number of the load equipment.
Optionally, the step of controlling load shedding at off-grid occurrence time further includes:
when the regional off-grid response controller receives an off-grid control command, rapidly responding to the load shedding sequence of the load equipment of S1 and S2 … … Sh of the SORT at the current moment, and time-sharing regulating and controlling to close the load equipment;
when the control sequence is closed to a certain load device, the regional parallel off-grid response controller generates a unit and a load summation current i in the regional f I of minimum generated current less than or equal to the historical contemporaneous time period min When the controller module pauses the closing of the follow-up load equipment through the contactor controller;
Wherein i is min Minimum generated current for a historical contemporaneous time period; i.e f The sum value of the sum current output by n power generation units and the sum current consumed by n load devices is i f When the power generation unit output current is equal to the load equipment consumption current; i.e f When the consumption current of the load equipment is more than 0, the consumption current of the load equipment is more than the output current of the power generation unit; i.e f When the consumption current of the load equipment is less than 0, the output current of the power generation unit is smaller;
generating unit and load summation current i in region in regional off-grid response controller f When the current is larger than or equal to the current time minimum load equipment current, the controller module turns off the current time minimum load equipment;
wherein i is smin Current is consumed for the minimum load device at the current moment in the regional and off-grid response controller.
Optionally, the step of controlling the input and load equipment of the power generation unit when the grid connection time occurs further includes:
when the regional grid-connected and off-grid response controller judges grid connection permission, load equipment is put into operation from small to large consumption power in sequence;
during the sequential loading process of the load equipment, the controller in the regional and off-grid response controller monitors the outlet voltage U ac Less than or equal to voltage coefficient delta l And lower limit standard U lgb The controller module pauses the input operation of the follow-up load equipment through the contactor controller;
Monitoring the outlet voltage U by a controller in the local and off-grid response controller ac Stabilized at U ac ±2％≥δ l U lgb When the method is used, the residual load equipment is continuously put into operation from small to large in sequence;
wherein U is ac Monitoring the outlet voltage for the controller; delta l Is the lower limit voltage fluctuation range coefficient; u (U) lgb Is the lower voltage limit standard.
Optionally, the step of controlling the input and load equipment of the power generation unit when the grid connection time occurs further includes:
when the regional grid-connected and off-grid response controller judges that grid connection is allowed, the power generation units in the regional grid-connected and off-grid response controller are sequentially put into operation from large to small power generation power;
monitoring the outlet voltage U by the controller in the regional parallel-to-off-grid response controller ac Less than or equal to voltage coefficient delta l And lower limit standard U lgb At the time, the voltage coefficient delta l And upper limit standard U lgb Product of (2) and grid voltage U ac Performing difference calculation to obtain an excess voltage delta U ac ＝δU lgb -U ac ；
The controller calculates and increases the output power of the multiple power generation units according to the voltage change in the current time period and the coefficient alpha=delta U/kW of the unit power generation power, wherein the output power is as follows:
Figure BDA0003357517550000051
according to the sequence from far to near of the power generation units, the communication module is used for generating power output power which is reduced by 10%;
monitoring the outlet voltage U by a controller module in the local off-grid response controller ac Stabilized at U ac ±2％≥δU lgb When the power generation unit is used, each power generation unit maintains or tracks the current power grid voltage output power; wherein U is ac Monitoring the outlet voltage for the controller; delta l Is the lower limit voltage fluctuation range coefficient; u (U) lgb Is the lower voltage limit standard.
In a second aspect, the present application further provides an area and off-network response control system, including: the device comprises a controller module, a multi-interface communication module, a carrier receiving module, a short circuit monitoring module, a voltage sensor, n current sensors, a contactor driving module and n contactors;
the input end of the contactor is connected with the micro-grid and a voltage sensor which is installed in parallel on the micro-grid, and the output end of the contactor is connected with the current sensor in series and is connected with m power generation units and h load devices, wherein n=m+h, and m and h are integers which are larger than or equal to 1;
the current sensor data outputs are all connected with a common data line; the Ad end of the public data line is connected with the data input end of the short circuit monitoring module, and the data output end of the short circuit monitoring module is connected with the data input end of the controller; the controller module is configured to collect data of the current sensor, short circuit states of the load device and the power generation unit, and collect the voltage sensor data;
The contactor control ends are correspondingly connected with n paths of output ends of the contactor driving module, and the data input end of the contactor driving module is connected with the data output end of the controller module; the data output end of the controller module controls the connection and disconnection of the contactor through the contactor driving module;
the contactor driving module further comprises a locking control end, wherein the locking control end is connected with the locking control end of the short circuit monitoring module, when any one of m power generation units or any one of h load devices is in fault short circuit, the associated contactor can be disconnected with a power grid, the locking control end in the associated monitoring module outputs fault state level, and the locking control end in the contactor driving module is locked; when the short circuit monitoring module monitors fault elimination, a locking control end of the short circuit monitoring module releases a locking state level;
the signal input end of the carrier receiving module is connected with a power grid, and the data analysis output end of the carrier receiving module is connected with the data input end of the controller module; the multi-interface communication module comprises m communication interfaces, and the communication interfaces are connected with the communication interfaces of the power generation unit through communication wires; the data output end of the communication module is connected with the communication input and output end of the controller module; the controller module is further configured to read power generation unit data in real time;
The controller module is further configured to:
step one, initializing setting, including setting type parameters of power generation equipment;
step two, the current direction is judged by monitoring the power generation unit and the load current in the analysis area, and the step two comprises the following steps:
the regional off-grid response controller monitors load power and power generation power of the power generation unit in real time through a current sensor and a voltage sensor so as to obtain a current direction;
when the controller calculates that the sum of the power generation unit and the load current is positive, the controller responds to the load equipment under the controller to consume micro-grid power for the region and off-grid, so that the load power is larger than the power generation power;
when the controller calculates that the sum of the power generation unit and the load current is negative, the power is released to the power grid for regional and off-grid response to the power generation of the power generation unit under the controller, so that the power generation power is larger than the load power;
when the controller calculates that the sum of the power generation unit and the load current is zero, the power generation power of the power generation unit is equal to the power consumption of the load equipment under the regional and off-grid response controller, so that the power generation power is equal to the load power;
predicting load shedding of load equipment and power increase and decrease of power of a power generation unit at the occurrence moment of the analysis grid;
and step four, controlling load shedding at off-grid occurrence time, which comprises the following steps:
When the regional off-grid response controller judges that off-grid occurs, the load equipment is turned off according to the prediction time sharing;
when the time-sharing control is closed to a certain load device, the controller calculates the sum i of the power generation units and the load current in the area f Less than or equal to the current threshold i min When the controller pauses the closing of the subsequent load equipment;
when the regional parallel off-grid response controller calculates to obtain the sum i of the power generation units and the load current in the region f Greater than the current threshold i min When the load power is the same as the load power, the controller turns off the load power minimum equipment at the current moment;
step five, controlling input and load equipment of a power generation unit when grid connection occurs, comprising the following steps:
the regional parallel off-grid response controller monitors the sum i of the output current and the load current of the power generation unit under the off-grid state f When the load is larger than 0, supplying power to the regional grid-connected and off-grid response controller for the micro-grid, and when the grid connection permission is judged, responding and controlling the grid connection method by the regional grid-connected and off-grid response controller;
the regional parallel off-grid response controller monitors the sum i of the output current and the load current of the power generation unit f And when the grid connection allowance is judged, the regional grid connection response controller responds to and controls the grid connection method.
According to the technical scheme, the regional off-grid response control method and the regional off-grid response control system are characterized by carrying out initialization setting on equipment in an off-grid region; monitoring and separating data information of a power generation unit and load equipment in the network area, determining the magnitude relation between the load power and the power generation power, and controlling the power generation unit to reduce the power generation power or turn off the load equipment in a time-sharing manner according to the magnitude relation between the load power and the power generation power when separating from the network; and when grid connection is performed, determining a control method for inputting the power generation unit and the load equipment according to a monitoring analysis result in an off-grid state. The power grid voltage stabilizing method has the advantages that the power grid voltage stabilizing method has high quick response and high accuracy, reduces impact of the distributed power generation system on the power grid, guarantees safe and stable operation of loads in the power distribution network, and solves the problem that a load protection device generally needs to set certain time delay to avoid short-circuit fault influence and cannot adapt to the construction requirements of a new-generation intelligent power grid.
Drawings
In order to more clearly illustrate the technical solutions of the present application, the drawings that are needed in the embodiments will be briefly described below, and it will be obvious to those skilled in the art that other drawings can be obtained from these drawings without inventive effort.
FIG. 1 is a schematic diagram of a microgrid topology;
FIG. 2 is a schematic diagram of a regional and off-grid response controller topology;
FIG. 3 is a flow chart of a method for controlling the regional and off-grid response controller.
Detailed Description
Reference will now be made in detail to the embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, the same numbers in different drawings refer to the same or similar elements, unless otherwise indicated. The embodiments described in the examples below do not represent all embodiments consistent with the present application. Merely as examples of systems and methods consistent with some aspects of the present application as detailed in the claims.
Referring to fig. 1, a schematic topology of a micro-grid is shown;
the regional micro-grid power supply system aims to overcome the defects that the voltage, the power and the frequency of a power grid fluctuate and the regional micro-grid is seriously subjected to off-grid switching failure caused by the change of the power supply environment and the power flow of the regional micro-grid at the moment of grid connection or off-grid, and therefore the regional off-grid response control device and the control method based on carrier communication, power prediction, load and power generation unit control are provided, and the micro-grid is enabled to be reliably switched without disturbance under the dual-mode of on-grid/off-grid, and the stable power grid is a future micro-grid demand. The micro-grid is a small power generation and distribution system composed of a distributed power supply, an energy storage device, an energy conversion device, a load, a monitoring and protecting device and the like.
The embodiment of the control device comprises an initialization module, a monitoring analysis module and a control module. The monitoring and analyzing module can comprise an interface communication module, a carrier receiving module, a short circuit monitoring module, a voltage sensor and n current sensors; the control module may include a multi-contactor drive module, n contactors; the input end of each of the n contactors is connected with the micro-grid and is also connected with a voltage sensor which is arranged in parallel on the micro-grid; the output ends of the n contactors are correspondingly connected with a current sensor in series and are connected with m power generation units and h load devices correspondingly.
Wherein n=m+h, m is an integer not less than 1, and h is an integer not less than 1. The data output ends of the n current sensors are connected with a common data line, one end of the common data line is connected with the data input end of the short circuit monitoring module, the data output end of the short circuit monitoring module is connected with the data input end of the controller, the data of the n current sensors, the short circuit states of the h load devices and the m power generation units are all collected by the controller, and the control module also collects the data of the voltage sensors.
The n contactor control ends are correspondingly connected with n paths of output ends of the contactor driving module, and the data input end of the contactor driving module is connected with the data output end of the control module. And the data output end of the control module is used for controlling the on and off of the n contactor through the contactor driving module.
The contactor driving module is provided with n locking control ends, the n locking control ends are connected with the locking control ends of the n short circuit monitoring modules, when a certain power generation unit or certain load equipment is in fault short circuit, the corresponding contactor is rapidly disconnected with the power grid, the locking control ends in the corresponding monitoring modules output fault state levels, and the locking control ends in the corresponding monitoring modules are locked through the corresponding locking control ends in the contactor driving modules. When the short circuit monitoring module monitors fault removal, the locking control end of the short circuit monitoring module releases the locking state level.
The signal input end of the carrier receiving module is connected with the power grid, and the data analysis output end of the carrier receiving module is connected with the data input end of the controller; the multi-interface communication module is provided with m communication interfaces, the m communication interfaces are connected with m communication interfaces of the corresponding power generation units through communication wires, the data output end of the communication module is connected with the communication input and output end of the control module, and the control module reads the data of the power generation units in real time;
referring to fig. 2, a specific control device in this embodiment is a topology schematic diagram of a regional and off-network response control device;
as shown in fig. 2, the control module, the multi-interface communication module, the carrier receiving module, the short circuit monitoring module, the U voltage sensor, the A1 … … An current sensor, the contactor driving module and the K1 … … Kn contactor are formed. The input Kin1 … … Kinn end of the K1 … … Kn contactor is connected with the micro-grid and is also connected with a U-voltage sensor which is arranged in parallel on the micro-grid; the output Kout1 … … Koutn ends of the K1 … … Kn contactor are correspondingly connected with the A1 … … An current sensor in series, and are correspondingly connected with the pv/pw1 … … pv/pwm power generation unit and the S1 … … Sh load equipment.
Wherein, n=m+h, m is greater than or equal to 1 integer, h is greater than or equal to 1 integer, A1 … … An current sensor data output is connected with a public data line, a public data line Ad end is connected with a data input Din end of a short circuit monitoring module, a short circuit monitoring module data output Dout end is connected with a controller data input id end, the data of the A1 … … An current sensor, the short circuit state of S1 … … Sh load equipment and a pv/pw1 … … pv/pwm generating unit are all collected by the controller, and the controller module also collects U voltage sensor data.
The K1 … … Kn contactor control Kop1 … … Kopn terminals are correspondingly connected with the Q1 … … Qn output ends of the contactor driving module, and the data input Qin end of the contactor driving module is connected with the data output Qout end of the controller module. And the data output Qout end of the controller module is used for controlling the on and off of the K1 … … Kn contactor through the contactor driving module.
The contactor driving module is provided with a Qb1 … … Qbn locking control end, the Qb1 … … Qbn locking control end is connected with a Db1 … … Dbn short circuit monitoring module locking control end, when a certain power generation unit in pv/pw1 … … pv/pwm or a certain load device in S1 … … Sh is in fault short circuit, the contactor in corresponding K1 … … Kn is rapidly disconnected and connected with a power grid, the Db1 … … Dbn locking control end in the corresponding monitoring module outputs fault state level, and the corresponding Qb1 … … Qbn locking control end in the contactor driving module is locked. When the short circuit monitoring module monitors fault removal, the short circuit monitoring module Qb1 … … Qbn latches the control terminal to release the latch state level.
The signal input Zb end of the carrier receiving module is connected with a power grid, and the data analysis output Zi end of the carrier receiving module is connected with the data input is end of the controller; the multi-interface communication module is provided with an R1 … … Rm communication interface, the R1 … … Rm communication interface is connected with a PR1 … … PRm communication interface of a corresponding power generation unit through a communication line, a data output RT1 end of the communication module is connected with a Ri end of a communication input/output port of the controller module, and the controller module reads pv/pw1 … … pv/pwm power generation unit data in real time;
working principle:
when the micro-grid is in a grid-connected state, a low-frequency carrier signal generator for monitoring the micro-grid and in an off-grid state sends a continuous group of coding command signals for broadcasting the grid-connected state in real time; when receiving the tripping signal of the previous stage, the method sends a continuous group of coded command signals broadcasting off-network states to the micro-network in real time.
When the regional on-line and off-line response control device monitors the coded command signals of the on-line and off-line states through the carrier wave receiving module, the coded command signals are received by the control module through analysis of the carrier wave module, and compared with the initialization data of the regional on-line and off-line response control device, the regional on-line and off-line response control device is identified, and the regional on-line and off-line response control device and/off-line working states are determined.
When the grid-connected working state is achieved, the regional grid-connected and off-grid response control device performs pre-analysis on the power generated by the multiple power generation units, the power consumption of the multiple load devices and the working state according to the current moment and the historical data, and the sudden change of the power grid in the off-grid process is avoided. According to the history contemporaneous power generation, power consumption and voltage curve, the voltage variation and the power generation and power consumption rules in different time periods are analyzed, and the history contemporaneous p is found out respectively with 15 minutes as a time period t1 ,p t2 …p t15 Maximum value p in power max 、u t1 ,u t2 …u t15 Voltage minimum value U min Sum voltage maximum U max . Voltage minimum value U min Description of load current i max Maximum, maximum voltage U max Description of load current i min And analyzing the internet surfing current or the load consumption current under the condition of the minimum load in the area according to the tide direction.
Wherein u is t1 Average voltage at 1 st minute for 15 min period of history synchronization; u (u) t2 Average voltage at 2 nd minute for 15 min period of history synchronization; u (u) t15 15 th minute average voltage for 15 th minute period of historical synchronization; p is p t1 Average power at 1 st minute for 15 min period of historical synchronization; p is p t2 Average power at 2 nd minute for 15 min period of historical synchronization; p is p t15 15 th minute average power for 15 th minute period of historical synchronization; i.e max For 15 minutes of history synchronizationA large current; p is p max Maximum power within 15 minutes of the history synchronization; u (U) min Minimum voltage within 15 minutes period for the contemporaneous history; u (U) max Maximum voltage within 15 minutes period for historical synchronization; i.e min Minimum current within 15 minutes of history synchronization;
the regional grid-connected and off-grid response control device monitors load power and power generation power of the power generation unit in real time through the current sensor and the voltage sensor, analyzes the trend direction, and consumes micro-grid power for load equipment under the regional grid-connected and off-grid response control device when the controller calculates the sum of the power generation unit and the load current as positive, namely, the load power is greater than the power generation power; when the controller calculates that the sum of the power generation unit and the load current is negative, the power is released to the power grid by the power generation unit under the regional and off-grid response control device, namely, the power generation power is greater than the load power; when the controller calculates that the sum of the power generation unit and the load current is zero, the power generation power of the power generation unit is equal to the power consumption of the load equipment under the regional and off-grid response control device, namely the power generation power=the load power.
In order to meet the requirement of the area and respond to the self-digestion of the area of the control device in an off-grid manner, a protocol code corresponding to load shedding and power increasing and decreasing of the power output by the power generation unit is established, and when the off-grid occurs, the controller closes the corresponding load through the contactor driver or sends the power increasing and decreasing protocol code to the power generation unit through the communication module according to the protocol code.
And when the load and the multiple power generation units are in a process after response control, the controller regulates and controls the shutdown of the load equipment and the increase and decrease of the output power of the power generation units in real time according to the principle that the power grid is stable, the power generation units generate power and are consumed in situ, and the residual power micro-grid is supported.
Wherein, the area is an area and is used for responding to all power generation units and loads in the control device off-grid; the short circuit monitoring module monitors whether the controllable multiple power generation unit and the load or the power generation equipment are short-circuited, and when the short circuit is monitored, the control module firstly controls the contactor driving module to control the contactor to be disconnected, and meanwhile sends a short circuit state signal to the control module, and the control module is locked and is prompted through LED lamplight flickering. When the short circuit monitoring module monitors that the short circuit state is not generated, the controller unlocks and controls the contactor driving module to switch on the contactor, and meanwhile, the LED light is normally-on to prompt that the once controllable multiple power generation unit is in short circuit;
referring to fig. 3, a flow chart of a control method of the regional off-grid response controller is shown;
as shown in fig. 3, the control method of the regional and off-grid response control device is as follows:
the first step, initializing settings, including power generation equipment types:
1) And (3) photovoltaic: string, grid-connected, capacity, number and distance to grid-connected points;
2) Wind power: capacity and number of single units;
3) Load attribute: inductive, capacitive, resistive, and power;
and secondly, monitoring the power generation units and the load current in the analysis area to judge the current direction.
The regional grid-connected and off-grid response control device monitors load power and power generation power of the power generation unit in real time through the current sensor and the voltage sensor, analyzes the current direction, and consumes micro-grid power for load equipment under the regional grid-connected and off-grid response control device when the sum of the power generation unit and the load current is calculated to be positive, namely, the load power is greater than the power generation power; when the sum of the power generation unit and the load current is calculated to be negative, the power is released to the power grid by the power generation unit under the regional and off-grid response control device, namely, the power generation power is greater than the load power; when the sum of the power generation unit and the load current is calculated to be zero, the power generation power of the power generation unit is equal to the power consumption of the load equipment under the regional and off-grid response control device, namely the power generation power=the load power;
and thirdly, predicting load shedding of load equipment and power increase and decrease of the power generation unit at the occurrence time of the analysis separation network.
1) When generated power > load power.
2) When the load power > the generated power.
And fourthly, load shedding control is carried out at off-grid occurrence time.
1) And when the regional and off-grid response control device judges that off-grid occurs, the load equipment is closed according to the prediction time sharing.
2) When the time-sharing control is closed to a certain load device, the sum i of the power generation unit and the load current in the area is calculated f ≤i min When the control device is in a closed state, the control device pauses the closing of the subsequent load equipment;
3) When the regional parallel off-grid response control device calculates and obtains the sum i of the power generation units and the load current in the region f ≥i smin And when the load power is the same as the load power, the control module turns off the load power minimum equipment at the current moment.
Fifth step, power generation unit input and load equipment control method when grid connection time occurs
1) The regional parallel off-grid response control device monitors the sum value i of the output current and the load current of the power generation unit under the off-grid state f When the load is more than 0, supplying power to the load in the regional grid-connected and off-grid response control device for the micro-grid, and when the grid connection permission is judged, responding and controlling a grid connection method by the regional grid-connected and off-grid response control device;
2) The regional parallel off-grid response control device monitors the sum value i of the output current and the load current of the power generation unit under the off-grid state f When the power is less than 0, the power generation unit in the regional parallel off-grid response control device supplies power to the micro-grid, and when the grid connection permission is judged, the regional parallel off-grid response control device responds to control the grid connection method;
The specific control method of the regional parallel off-grid response control device is as follows:
the first step, initializing settings, including power generation equipment types:
1) And (3) photovoltaic: string, grid-connected, capacity, number and distance to grid-connected points;
2) Wind power: single machine capacity and number;
3) Load attribute: load type inductance, capacitance, resistance, and power;
the change of power in the regional off-grid response control device causes the change of the outlet voltage of the regional off-grid response control device due to the reason of the line impedance and the load attribute between the regional off-grid response control device and the regional off-grid response control device, thereby firstly dividing the hour into 4 hours at 15 minutesInterval, in each time interval unit generation power and voltage change coefficient are initially set
Figure BDA0003357517550000101
Iteration of self-learning with increasing data volume to obtain new optimal voltage variation coefficient of unit generated power ∈ ->
Figure BDA0003357517550000102
And secondly, monitoring the power generation units and the load current in the analysis area to judge the current direction.
The regional off-grid response control device is connected in series with a current sensor and a voltage sensor connected in parallel with a total outlet through each control contactor loop, monitors the power of each path of load equipment and the power of each path of power generation unit in real time, and determines the working state of each power generation unit. Analyzing the current direction, and the control device reads the current data output by all the generating units at the current moment and sums the current data to obtain-i pz ＝(-i p1 )+(-i p2 )+……(-i pm ) The current, and the consumption current of the load device are summed to obtain i sz ＝i s1 +i s2 +……i sh Current, the power generation unit outputs summation current i pz Summing the consumption current i with the load device sz And summing to obtain the total current i in the region zn ＝-i zp +i zs . When the control device analyses the total current i in the area zn In order to be positive, the power of the power grid is consumed by the load equipment under the regional and off-grid response control device, namely the load power>Generating power; when the control device analyses the total current i in the area zn When the power is negative, the power is released to the power grid by the power generation unit under the regional off-grid response control device, namely the power generation power>Load power; when the control device analyses the total current i in the area zn When the power is zero, the power generated by the power generation unit is equal to the power consumed by the load equipment under the regional and off-grid response control device, namely the power generated = load power;
wherein, the area is an area and is used for responding to all power generation units and loads in the control device off-grid;
the output current of the power generation unit is negative, and the output current is respectively: i.e p1 Outputting current for the 1 st power generation unit; i.e p2 Outputting current for the 2 nd generating unit; i.e pm Outputting current for the m-th power generation unit; i.e pz Outputting the sum of the currents for all the power generation units; the load consumption current is positive: i.e s1 Current is consumed for the 1 st load; i.e s2 Current is consumed for the 2 nd load; i.e sh Current is consumed for the h stage load; i.e sz The sum of the current consumption for all loads;
i f the total output current of the power generation unit is the total output current of the power generation unit during off-grid operation; i.e zn Is the total current of the region;
and thirdly, predicting and analyzing the load shedding of the multi-load equipment and the increase and decrease of the power of the multi-power generation unit at the off-grid moment.
1) When generated power > load power.
When the current monitored by the regional grid-connected and off-grid response control device is negative, the power generated by the power generation unit in the regional grid-connected and off-grid response control device cannot be absorbed by the load equipment in the region, and the power is supplied to the power grid, namely the power generation power>Load power; when the grid-connected moment occurs, the power output in the regional grid-connected response control device cannot be sent outwards, so that the power grid voltage is suddenly changed, and therefore, in the grid-connected working state, the controller of the regional grid-connected response control device performs pre-analysis on the working power and the state of the multiple power generation units according to the current moment and the historical data, and in order to avoid rapid change of the power grid in the grid-connected process, the voltage change at different time intervals and the coefficient of the unit power generation power are analyzed according to the historical synchronous power generation power and the voltage curve
Figure BDA0003357517550000111
And respectively find out the maximum value p of the historical contemporaneous power by taking 15 minutes as a period max ＝max(p t1 ,p t2 …p t15 ) Minimum voltage U min ＝min(u t1 ,u t2 …u t15 ) And the highest voltage U max ＝max(u t1 ,u t2 …u t15 ) The former illustrates the maximum load
Figure BDA0003357517550000112
The latter illustrates that the load is minimal->
Figure BDA0003357517550000113
This current is the internet current at minimum load. The controller reads the output current i of all the generating units at the current moment p1 ……i pm And sum the current i pz When i min ≤i pz ≤i max When the current i is summed pz Subtracting the on-line current to obtain the output current i of the power generation unit at the off-line moment of the micro-grid f ＝i pz -i min Thereby obtaining the ratio of the sum current of the generating units at the present moment +.>
Figure BDA0003357517550000114
According to the ratio i of the currents fn And performing product operation with the output current of each power generation unit to obtain the output current of each power generation unit.
And when off-grid operation occurs, the controller sends out the power reduction protocol code to the multiple power generation units through the communication module according to the analysis result.
Wherein u is t1 A 1 st minute voltage that is a 15 th minute period of historical synchronization; u (u) t2 2 nd minute voltage for 15 th minute period of history synchronization; u (u) t15 15 th minute voltage, which is a 15 th minute period of historical synchronization; p is p t1 1 st minute power for 15 minute period of history synchronization; p is p t2 2 nd minute power for 15 th minute period of history synchronization; p is p t15 15 th minute power for 15 th minute period of historical synchronization; i.e max Maximum current in 15 minutes period for historical synchronization; p is p max Maximum power within 15 minutes of the history synchronization; u (U) min Minimum voltage within 15 minutes period for the contemporaneous history; u (U) max Maximum voltage within 15 minutes period for historical synchronization; i.e min Minimum current within 15 minutes of history synchronization; i.e fn For generating power during grid connection and total output current of power generation unit during off-grid operationThe total output current of the unit is calculated; i.e f The total output current of the power generation unit is the total output current of the power generation unit during off-grid operation; alpha is the coefficient of voltage variation and generated power in different time periods.
2) When the load power > the generated power.
Analysis of i by regional parallel-to-off-grid response control device in grid-connected state sz ＞i pz I.e. load power>The power generation power is judged to be positive, the power generation power of the power generation unit under the regional off-grid response control device cannot meet the consumption requirement of load equipment, and the power is supplied by the power grid in a supplementing mode; when off-grid time occurs, unimportant loads of the micro-grid should be reduced rapidly, so that abrupt changes of the grid voltage are caused. Therefore, the load shedding of the micro-grid is realized by carrying out load shedding on load equipment in the regional off-grid response control device, so that the generated power and the load consumption power of the power generation unit are approximately balanced.
In the grid-connected working state, the regional grid-connected response control device analyzes according to historical data and the power consumption conditions of the load devices of S1 and S2 … … Sh at the moment, sorts the power consumption of the load devices of S1 and S2 … … Sh from large to small, and sorts the power consumption of the load devices of S1 and S2 … … Sh from large to small in the future 24 hours. The working state and power of each load device change along with the change of time within the future 24 hours, so that the off-line load device is firstly eliminated by the following formula:
processDate(P S1 、P S2 ……P Sh ，P ShState ，m)；
the load equipment of the S1 and S2 … … Sn at any moment is provided with the following power consumption load shedding sequential function from large to small:
sort(processDate(P S1 、P S2 ……P Sn ，P SnState ，m)，'descend')；
thus, the load shedding sequence of the S1 and S2 … … Sh load equipment is adjusted in real time, so that the voltage of the micro-grid is prevented from greatly fluctuating.
Wherein S1 is the 1 st load, S2 is the 2 nd load, sh is the h load, h is an integer more than or equal to 1; p (P) S1 Is negative at a certain moment of the 1 st loadCharge power, P S2 Load power P at a certain moment for the 2 nd load Sm The load power at a certain moment is the mth load; the sort is a sort function at a certain moment; processDate is a function of screening out off-line status load devices; p (P) ShState And h is the number of the load devices.
Fourth step, load reducing equipment control
1) When the regional off-grid response control device receives an off-grid control command, the regional off-grid response control device rapidly responds to the load shedding sequence of the load equipment of S1 and S2 … … Sh of the SORT at the current moment, and the load equipment is closed in a time-sharing control mode.
2) When the control sequence is closed to a certain load device, the regional parallel off-grid response control device comprises a regional power generation unit and a load summation current i f I of minimum generated current equal to or less than the historical contemporaneous time period min I.e. i f ≤i min The controller pauses the closing of the subsequent load device by the contactor controller.
Wherein i is min Minimum generated current for a historical contemporaneous time period; i.e f A sum of the sum current outputted from the n power generation units and the sum current consumed by the n load devices,
when i f When the power generation unit output current is equal to the load equipment consumption current; i.e f When the consumption current of the load equipment is more than 0, the consumption current of the load equipment is more than the output current of the power generation unit; i.e f When the consumption current of the load equipment is less than 0, the output current of the power generation unit is smaller;
3) In-region generating unit and load summation current i in regional parallel-off-grid response control device f At least equal to or greater than the current moment, i.e. i f ≥i smin When the controller will shut down the minimum load device at the present moment.
Wherein i is smin The current consumption of the minimum load equipment at the current moment in the regional and off-grid response control device is controlled;
and fifthly, predicting and analyzing the input power generation unit and the load equipment control method at the grid-connected time under the off-grid state.
1) Region(s)And the off-grid response control device monitors the sum value i of the output currents of m power generation units and the consumption currents of h load devices in real time in an off-grid state f When i f When the power is more than 0, judging that the micro-grid supplies power to the load in the regional off-grid response control device, namely the load power in the regional off-grid response control device>The power generation unit generates power. Therefore, when the regional parallel-to-off-grid response control device judges that grid connection is allowed, the control method comprises the following steps:
(1) the load equipment is put into operation from small to large consumption power.
(2) In the process of sequentially throwing load equipment, monitoring the outlet voltage U by a controller in the regional off-grid response control device ac Less than or equal to voltage coefficient delta l And lower limit standard U lgb U, i.e. U ac ≤δ l U lgb And when the controller is in a state of suspending the input operation of the follow-up load equipment through the contactor controller.
(3) Monitoring the outlet voltage U by a controller in the local off-grid response control device ac Tend to stabilize at U ac ±2％≥δ l U lgb And when the residual load equipment is continuously put into operation from small to large in sequence.
Wherein U is ac Monitoring the outlet voltage for the controller; delta l Is the lower limit voltage fluctuation range coefficient; u (U) lgb Is the lower voltage limit standard.
(4) And (3) in the closing process of the input power generation unit and the load equipment control method step (3) at the grid-connected time, the regional grid-connected and off-grid response control device continues to control the process by executing the steps (2) to (3) until the load equipment is completely put into operation.
2) The regional parallel off-grid response control device monitors the sum value i of output currents of m power generation units and h load currents in real time under the off-grid state f When i f When the power is less than 0, judging that the power generation unit in the regional off-grid response control device supplies power to the micro-grid, namely the load power in the regional off-grid response control device<The power generation unit generates power, and therefore when the regional grid-connected and off-grid response control device judges that grid connection is allowed, the control method comprises the following steps:
(1) and sequentially putting the power generation units in the regional off-grid response control device into operation from large to small power generation power.
(2) In the process of orderly putting the regional parallel-off-grid response control device into operation, the voltage of the micro-grid is in a front high-low state and a rear low state due to line loss and the input of non-important load equipment of the micro-grid, and a controller in the regional parallel-off-grid response control device monitors the outlet voltage U ac Less than or equal to voltage coefficient delta l And lower limit standard U lgb U, i.e. U ac ≤δ l U lgb At the time, the voltage coefficient delta l And upper limit standard U lgb Product of (2) and grid voltage U ac Performing difference calculation to obtain an excess voltage delta U ac ＝δ l U lgb -U ac The controller calculates and increases the output power of the multiple power generation units according to the voltage change in the current time period and the coefficient alpha=delta U/kW of the unit power generation power, wherein the output power is as follows:
Figure BDA0003357517550000131
the output power distribution output of the controllable multiple power generation unit is reduced by the following steps: the array compares the number formulas of the power generation units.
And according to the sequence from far to near of the power generation units, the power generation output power is reduced by 10% through the communication module.
(3) Monitoring the outlet voltage U by a controller in the local off-grid response control device ac Tend to stabilize at U ac ±2％≥δ l U lgb When each power generation unit will maintain or track the current grid voltage output power.
Wherein U is ac Monitoring the outlet voltage for the controller; delta l Is the lower limit voltage fluctuation range coefficient; u (U) lgb Is the lower voltage limit standard.
According to the technical scheme, the regional off-grid response control method and the regional off-grid response control system are characterized by carrying out initialization setting on equipment in an off-grid region; monitoring and separating data information of a power generation unit and load equipment in a network area, determining the magnitude relation between load power and power generation power, and controlling the power generation unit to reduce the power generation power and closing the load equipment in a time-sharing manner according to the magnitude relation between the load power and the power generation power when the network is separated; and when grid connection is performed, determining a control method for inputting the power generation unit and the load equipment according to a monitoring analysis result in an off-grid state. The power grid voltage stabilizing method has the advantages that the power grid voltage stabilizing method has high quick response and high accuracy, reduces impact of the distributed power generation system on the power grid, guarantees safe and stable operation of loads in the power distribution network, and solves the problem that a load protection device generally needs to set certain time delay to avoid short-circuit fault influence and cannot adapt to the construction requirements of a new-generation intelligent power grid.
The foregoing detailed description of the embodiments is merely illustrative of the general principles of the present application and should not be taken in any way as limiting the scope of the invention. Any other embodiments developed in accordance with the present application without inventive effort are within the scope of the present application for those skilled in the art.

Claims (10)

1. A regional on-off-grid response control method, applied to a regional on-grid response controller, the controller comprising: the device comprises a controller module, a multi-interface communication module, a carrier receiving module, a short circuit monitoring module, a voltage sensor, n current sensors, a contactor driving module and n contactors;
the input end of the contactor is connected with the micro-grid and a voltage sensor which is installed in parallel on the micro-grid, and the output end of the contactor is connected with the current sensor in series and is connected with m power generation units and h load devices, wherein n=m+h, and m and h are integers which are larger than or equal to 1;
the current sensor data outputs are all connected with a common data line; the Ad end of the public data line is connected with the data input end of the short circuit monitoring module, and the data output end of the short circuit monitoring module is connected with the data input end of the controller; the controller module is configured to collect data of the current sensor, short circuit states of the load device and the power generation unit, and collect the voltage sensor data;
The contactor control ends are correspondingly connected with n paths of output ends of the contactor driving module, and the data input end of the contactor driving module is connected with the data output end of the controller module; the data output end of the controller module controls the connection and disconnection of the contactor through the contactor driving module;
the contactor driving module further comprises a locking control end, wherein the locking control end is connected with the locking control end of the short circuit monitoring module, when any one of m power generation units or any one of h load devices is in fault short circuit, the associated contactor can be disconnected with a power grid, the locking control end in the associated monitoring module outputs fault state level, and the locking control end in the contactor driving module is locked; when the short circuit monitoring module monitors fault elimination, a locking control end of the short circuit monitoring module releases a locking state level;
the signal input end of the carrier receiving module is connected with a power grid, and the data analysis output end of the carrier receiving module is connected with the data input end of the controller module; the multi-interface communication module comprises m communication interfaces, and the communication interfaces are connected with the communication interfaces of the power generation unit through communication wires; the data output end of the communication module is connected with the communication input and output end of the controller module; the controller module is further configured to read power generation unit data in real time;
The regional parallel-to-off-network response control method comprises the following steps:
step one, initializing setting, including setting type parameters of power generation equipment;
step two, the current direction is judged by monitoring the power generation unit and the load current in the analysis area, and the step two comprises the following steps:
the regional off-grid response controller monitors load power and power generation power of the power generation unit in real time through a current sensor and a voltage sensor so as to obtain a current direction;
when the controller calculates that the sum of the power generation unit and the load current is positive, the controller responds to the load equipment under the controller to consume micro-grid power for the region and off-grid, so that the load power is larger than the power generation power;
when the controller calculates that the sum of the power generation unit and the load current is negative, the power is released to the power grid for regional and off-grid response to the power generation of the power generation unit under the controller, so that the power generation power is larger than the load power;
when the controller calculates that the sum of the power generation unit and the load current is zero, the power generation power of the power generation unit is equal to the power consumption of the load equipment under the regional and off-grid response controller, so that the power generation power is equal to the load power;
predicting load shedding of load equipment and power increase and decrease of power of a power generation unit at the occurrence moment of the analysis grid;
and step four, controlling load shedding at off-grid occurrence time, which comprises the following steps:
When the regional off-grid response controller judges that off-grid occurs, the load equipment is turned off according to the prediction time sharing;
when the time-sharing control is closed to a certain load device, the controller calculates the sum i of the power generation units and the load current in the area f Less than or equal to the current threshold i min When the controller pauses the closing of the subsequent load equipment;
when the regional parallel off-grid response controller calculates to obtain the sum i of the power generation units and the load current in the region f Greater than the current threshold i min When the load power is the same as the load power, the controller turns off the load power minimum equipment at the current moment;
step five, controlling input and load equipment of a power generation unit when grid connection occurs, comprising the following steps:
the regional parallel off-grid response controller monitors the sum i of the output current and the load current of the power generation unit under the off-grid state f When the load is larger than 0, supplying power to the regional grid-connected and off-grid response controller for the micro-grid, and when the grid connection permission is judged, responding and controlling the grid connection method by the regional grid-connected and off-grid response controller;
the regional parallel off-grid response controller monitors the sum i of the output current and the load current of the power generation unit f When the power supply voltage is smaller than 0, the power generation unit in the regional parallel-to-off-grid response controller supplies power to the micro-grid, and when the grid connection permission is judged, the regional parallel-to-off-grid response controller responds to control the grid connection method 。
2. The regional on-line and off-line response control method according to claim 1, wherein the initialization setting includes:
setting the string type, grid-connected type, capacity, quantity and distance between the photovoltaic power generation equipment and grid-connected points;
setting the single-machine capacity and the number of the wind power generation equipment;
the load sensitivity, the capacity, the resistance and the power of the load equipment are set.
3. The regional on-line and off-line response control method according to claim 2, wherein the initialization setting further includes:
dividing each hour into 4 time periods in 15 minutes, and initially setting unit generation power and voltage change coefficient in each time period
Figure FDA0004280064860000021
The new voltage change coefficient of unit power generation is iterated from the learning with the increase of the data volume
Figure FDA0004280064860000022
Wherein DeltaU is a voltage variable, and kW is an initial set unit generation power.
4. The regional on-grid response control method according to claim 1, wherein the step of monitoring the power generation unit and the load current in the analysis region to determine the current direction further comprises:
the controller module reads current data output by all the power generation units at the current moment and consumed current of the load equipment;
Summing current data to obtain-i pz ＝(-i p1 )+(-i p2 )+……(-i pm ) Current, where i p1 Outputting current for the 1 st power generation unit; i.e p2 Outputting current for the 2 nd generating unit; i.e pm Outputting current for the m-th power generation unit; i.e pz Outputting the sum of the currents for all the power generation units;
summing up the consumption currents to obtain i sz ＝i s1 +i s2 +……i sh A current; wherein i is s1 Current is consumed for the 1 st load; i.e s2 Current is consumed for the 2 nd load; i.e sh Current is consumed for the h stage load; i.e sz The sum of the current consumption for all loads; i.e f The total output current of the power generation unit is the total output current of the power generation unit during off-grid operation;
summing the output of the power generation unit with the current i pz Summing the consumption current i with the load device sz And summing to obtain the total current i in the region zn ＝-i pz +i sz 。
5. The regional on-grid response control method according to claim 1, wherein in the step of predicting load shedding of the load device and power increase/decrease of the power generation unit at the time of occurrence of the analysis of the off-grid, when the generated power is larger than the load power, further comprising:
when the current monitored by the regional grid-connected and off-grid response controller is negative in the grid-connected state, the controller module performs pre-analysis on the working power and the state of the multiple power generation unit according to the current moment and the historical data in the grid-connected working state so as to analyze the voltage change in different time periods and the coefficient of the unit power generation power
Figure FDA0004280064860000031
Wherein alpha is the coefficient of voltage change and generated power in different time periods;
wherein DeltaU is a voltage variable, and kW is an initial set unit power generation power;
and respectively find out the maximum value p of the historical contemporaneous power by taking 15 minutes as a period max ＝max(p t1 ,p t2 …p t15 ) Minimum voltage U min ＝min(u t1 ,u t2 …u t15 ) And the highest voltage U max ＝max(u t1 ,u t2 …u t15 ) The method comprises the steps of carrying out a first treatment on the surface of the Wherein u is t1 A 1 st minute voltage that is a 15 th minute period of historical synchronization; u (u) t2 2 nd minute voltage for 15 th minute period of history synchronization; u (u) t15 15 th minute voltage, which is a 15 th minute period of historical synchronization; p is p t1 1 st minute power for 15 minute period of history synchronization; p is p t2 2 nd minute power for 15 th minute period of history synchronization; p is p t15 15 th minute power for 15 th minute period of historical synchronization; i.e max Maximum current in 15 minutes period for historical synchronization; p is p max Maximum power within 15 minutes of the history synchronization; u (U) min Minimum voltage within 15 minutes period for the contemporaneous history; u (U) max Maximum voltage within 15 minutes period for historical synchronization;
calculating maximum load
Figure FDA0004280064860000032
And minimum load->
Figure FDA0004280064860000033
As the internet current under the minimum load condition;
the controller module reads the output currents i of all the generating units at the current moment p1 ……i pm And sum the current i pz ；
Wherein i is p1 Outputting current for the 1 st power generation unit; i.e pm Outputting current for the m-th power generation unit;
when i min ≤i pz ≤i max When the current i is summed pz Subtracting the on-line current to obtain the output current i of the power generation unit at the off-line moment of the micro-grid f ＝i pz -i min Obtaining the ratio of the summation current of the generating units at the current moment
Figure FDA0004280064860000034
According to the ratio i of the currents fn Performing product operation with the output current of each power generation unit to obtain the output current of each power generation unit; wherein i is min Minimum current within 15 minutes of history synchronization; i.e fn For total output of power generation unit during off-grid operationThe ratio of the output current to the total output current of the power generation unit during grid connection; i.e f The total output current of the power generation unit is the total output current of the power generation unit during off-grid operation;
and establishing a protocol code of the power generation unit corresponding to the power-off or power-reduction output, and sending the power-reduction protocol code to the multiple power generation unit through the communication module according to the analysis result by the controller module when off-grid operation occurs.
6. The regional on-grid response control method according to claim 5, wherein in the step of predicting load shedding of the load device and power increase/decrease of the power generation unit at the time of occurrence of the analysis of the off-grid, when the load power is larger than the generated power, further comprising:
load shedding of load equipment in the regional off-grid response controller is realized, so that the power generation power of the power generation unit and the load consumption power are approximately balanced, and the load of the micro-grid is reduced;
in the grid-connected working state, the regional grid-connected and off-grid response controller analyzes according to historical data and the power consumption condition of the load equipment of S1 and S2 … … Sh at the moment;
Sequencing the S1, S2 … … Sh load devices from large to small in power consumption at the moment, and sequencing the S1, S2 … … Sh devices from large to small in power consumption at the future 24-hour time;
the working state and power of each load device change along with the change of time within the future 24 hours, so that the off-line load device is firstly eliminated by the following formula:
processDate(PS1、PS2……PSh，PShState，m)；
the load equipment of the S1 and S2 … … Sn at any moment is provided with the following power consumption load shedding sequential function from large to small:
sort(processDate(PS1、PS2……PSn，PSnState，m)，'descend')；
therefore, the load shedding sequence of the S1 and S2 … … Sh load equipment is adjusted in real time, so that the voltage of the micro-grid is prevented from greatly fluctuating;
wherein S1 is the 1 st load, S2 is the 2 nd load, sh is the h load, h is an integer more than or equal to 1; PS1 is the load power of the 1 st load at a certain moment, PS2 is the load power of the 2 nd load at a certain moment, and PSm is the load power of the m-th load at a certain moment; the sort is a sort function at a certain moment; processDate is a function of screening out off-line status load devices; PShState is the state of the load equipment, and h is the number of the load equipment.
7. The regional off-grid response control method of claim 1, wherein the step of controlling load shedding at the off-grid occurrence time further comprises:
When the regional off-grid response controller receives an off-grid control command, rapidly responding to the load shedding sequence of the load equipment of S1 and S2 … … Sh of the SORT at the current moment, and time-sharing regulating and controlling to close the load equipment;
wherein S1 is the 1 st load, S2 is the 2 nd load, sh is the h load;
when the control sequence is closed to a certain load device, the regional parallel off-grid response controller generates a unit and a load summation current i in the regional f I of minimum generated current less than or equal to the historical contemporaneous time period min When the controller module pauses the closing of the follow-up load equipment through the contactor controller;
wherein i is min Minimum generated current for a historical contemporaneous time period; i.e f The sum value of the sum current output by n power generation units and the sum current consumed by n load devices is i f When the power generation unit output current is equal to the load equipment consumption current; i.e f When the consumption current of the load equipment is more than 0, the consumption current of the load equipment is more than the output current of the power generation unit; i.e f When the consumption current of the load equipment is less than 0, the output current of the power generation unit is smaller;
generating unit and load summation current i in region in regional off-grid response controller f When the current is larger than or equal to the current time minimum load equipment current, the controller module turns off the current time minimum load equipment;
Wherein i is smin Current is consumed for the minimum load device at the current moment in the regional and off-grid response controller.
8. The regional on-grid and off-grid response control method according to claim 1, wherein the step of controlling the input and load equipment of the power generation unit at the time of grid-connected time further comprises:
when the regional grid-connected and off-grid response controller judges grid connection permission, load equipment is put into operation from small to large consumption power in sequence;
during the sequential loading process of the load equipment, the controller in the regional and off-grid response controller monitors the outlet voltage U ac Less than or equal to voltage coefficient delta l And lower limit standard U lgb The controller module pauses the input operation of the follow-up load equipment through the contactor controller;
monitoring the outlet voltage U by a controller in the local and off-grid response controller ac Stabilized at U ac ±2％≥δ l U lgb When the method is used, the residual load equipment is continuously put into operation from small to large in sequence;
wherein U is ac Monitoring the outlet voltage for the controller; delta l Is the lower limit voltage fluctuation range coefficient; u (U) lgb Is the lower voltage limit standard.
9. The regional on-grid and off-grid response control method according to claim 8, wherein the step of controlling the input and load equipment of the power generation unit at the time of grid-connected time further comprises:
When the regional grid-connected and off-grid response controller judges that grid connection is allowed, the power generation units in the regional grid-connected and off-grid response controller are sequentially put into operation from large to small power generation power;
monitoring the outlet voltage U by the controller in the regional parallel-to-off-grid response controller ac Less than or equal to voltage coefficient delta l And lower limit standard U lgb At the time, the voltage coefficient delta l And upper limit standard U lgb Product of (2) and grid voltage U ac Performing difference calculation to obtain an excess voltage delta U ac ＝δU lgb -U ac ；
The controller calculates a plurality of power generation units according to the voltage change in the current time period and the coefficient alpha=delta U/kW of the unit power generation powerThe meta output power is:
Figure FDA0004280064860000051
wherein DeltaU is a voltage variable, and kW is an initial set unit power generation power;
according to the sequence from far to near of the power generation units, the communication module is used for generating power output power which is reduced by 10%;
monitoring the outlet voltage U by a controller module in the local off-grid response controller ac Stabilized at U ac ±2％≥δU lgb When the power generation unit is used, each power generation unit maintains or tracks the current power grid voltage output power; wherein U is ac Monitoring the outlet voltage for the controller; delta l Is the lower limit voltage fluctuation range coefficient; u (U) lgb Is the lower voltage limit standard.
10. An area and off-grid response control system, comprising: the device comprises a controller module, a multi-interface communication module, a carrier receiving module, a short circuit monitoring module, a voltage sensor, n current sensors, a contactor driving module and n contactors;
The input end of the contactor is connected with the micro-grid and a voltage sensor which is installed in parallel on the micro-grid, and the output end of the contactor is connected with the current sensor in series and is connected with m power generation units and h load devices, wherein n=m+h, and m and h are integers which are larger than or equal to 1;
the current sensor data outputs are all connected with a common data line; the Ad end of the public data line is connected with the data input end of the short circuit monitoring module, and the data output end of the short circuit monitoring module is connected with the data input end of the controller; the controller module is configured to collect data of the current sensor, short circuit states of the load device and the power generation unit, and collect the voltage sensor data;
the contactor control ends are correspondingly connected with n paths of output ends of the contactor driving module, and the data input end of the contactor driving module is connected with the data output end of the controller module; the data output end of the controller module controls the connection and disconnection of the contactor through the contactor driving module;
the contactor driving module further comprises a locking control end, wherein the locking control end is connected with the locking control end of the short circuit monitoring module, when any one of m power generation units or any one of h load devices is in fault short circuit, the associated contactor can be disconnected with a power grid, the locking control end in the associated monitoring module outputs fault state level, and the locking control end in the contactor driving module is locked; when the short circuit monitoring module monitors fault elimination, a locking control end of the short circuit monitoring module releases a locking state level;
The signal input end of the carrier receiving module is connected with a power grid, and the data analysis output end of the carrier receiving module is connected with the data input end of the controller module; the multi-interface communication module comprises m communication interfaces, and the communication interfaces are connected with the communication interfaces of the power generation unit through communication wires; the data output end of the communication module is connected with the communication input and output end of the controller module; the controller module is further configured to read power generation unit data in real time;
the controller module is further configured to:
step one, initializing setting, including setting type parameters of power generation equipment;
step two, the current direction is judged by monitoring the power generation unit and the load current in the analysis area, and the step two comprises the following steps:
the regional off-grid response controller monitors load power and power generation power of the power generation unit in real time through a current sensor and a voltage sensor so as to obtain a current direction;
when the controller calculates that the sum of the power generation unit and the load current is positive, the controller responds to the load equipment under the controller to consume micro-grid power for the region and off-grid, so that the load power is larger than the power generation power;
when the controller calculates that the sum of the power generation unit and the load current is negative, the power is released to the power grid for regional and off-grid response to the power generation of the power generation unit under the controller, so that the power generation power is larger than the load power;
When the controller calculates that the sum of the power generation unit and the load current is zero, the power generation power of the power generation unit is equal to the power consumption of the load equipment under the regional and off-grid response controller, so that the power generation power is equal to the load power;
predicting load shedding of load equipment and power increase and decrease of power of a power generation unit at the occurrence moment of the analysis grid;
and step four, controlling load shedding at off-grid occurrence time, which comprises the following steps:
when the regional off-grid response controller judges that off-grid occurs, the load equipment is turned off according to the prediction time sharing;
when the time-sharing control is closed to a certain load device, the controller calculates the sum i of the power generation units and the load current in the area f Less than or equal to the current threshold i min When the controller pauses the closing of the subsequent load equipment;
when the regional parallel off-grid response controller calculates to obtain the sum i of the power generation units and the load current in the region f Greater than the current threshold i min When the load power is the same as the load power, the controller turns off the load power minimum equipment at the current moment;
step five, controlling input and load equipment of a power generation unit when grid connection occurs, comprising the following steps:
the regional parallel off-grid response controller monitors the sum i of the output current and the load current of the power generation unit under the off-grid state f When the load is larger than 0, supplying power to the regional grid-connected and off-grid response controller for the micro-grid, and when the grid connection permission is judged, responding and controlling the grid connection method by the regional grid-connected and off-grid response controller;
the regional parallel off-grid response controller monitors the sum i of the output current and the load current of the power generation unit f And when the grid connection allowance is judged, the regional grid connection response controller responds to and controls the grid connection method.
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