CN111628572B - Intelligent response system and method for user side direct current micro-grid - Google Patents

Intelligent response system and method for user side direct current micro-grid Download PDF

Info

Publication number
CN111628572B
CN111628572B CN202010369576.0A CN202010369576A CN111628572B CN 111628572 B CN111628572 B CN 111628572B CN 202010369576 A CN202010369576 A CN 202010369576A CN 111628572 B CN111628572 B CN 111628572B
Authority
CN
China
Prior art keywords
power
energy
voltage
load
converter
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202010369576.0A
Other languages
Chinese (zh)
Other versions
CN111628572A (en
Inventor
郭权利
苑舜
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to CN202010369576.0A priority Critical patent/CN111628572B/en
Publication of CN111628572A publication Critical patent/CN111628572A/en
Application granted granted Critical
Publication of CN111628572B publication Critical patent/CN111628572B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J13/00—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
    • H02J13/00004—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by the power network being locally controlled
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J13/00—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
    • H02J13/00032—Systems characterised by the controlled or operated power network elements or equipment, the power network elements or equipment not otherwise provided for
    • 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
    • H02J3/28—Arrangements for balancing of the load in a network by storage of energy
    • H02J3/32—Arrangements for balancing of the load in a network by storage of energy using batteries with converting means
    • 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
    • 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
    • H02J2300/26—The renewable source being solar energy of photovoltaic origin involving maximum power point tracking control for photovoltaic sources
    • 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
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy
    • Y02E10/56—Power conversion systems, e.g. maximum power point trackers
    • 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
    • Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
    • Y02E40/70—Smart grids as climate change mitigation technology in the energy generation sector
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
    • Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
    • Y04S10/00—Systems supporting electrical power generation, transmission or distribution
    • Y04S10/12—Monitoring or controlling equipment for energy generation units, e.g. distributed energy generation [DER] or load-side generation
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
    • Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
    • Y04S10/00—Systems supporting electrical power generation, transmission or distribution
    • Y04S10/14—Energy storage units
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
    • Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
    • Y04S10/00—Systems supporting electrical power generation, transmission or distribution
    • Y04S10/50—Systems or methods supporting the power network operation or management, involving a certain degree of interaction with the load-side end user applications
    • 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
    • Y04S40/126—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 wireless data transmission
    • 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
    • Y04S40/128—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 involving the use of Internet protocol

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Supply And Distribution Of Alternating Current (AREA)

Abstract

The invention belongs to the field of new energy and power demand side response, and particularly relates to a user side direct current micro-grid intelligent response system and method, and a ubiquitous power internet of things energy management terminal technical method. The invention divides the response sequence in the power distribution of the DC micro-grid implementation of the source, the load and the storage at the user side according to the upper computer energy optimization scheme, improves the voltage layering control strategy of the DC micro-grid according to the response sequence, and sets the power given value and the droop characteristic of the source, the load and the storage interface converter. The demand response instruction is executed by flexibly setting the response sequence of the source, the load and the storage in the voltage stabilization of the micro-grid and stably switching the different response sequences of the source, the load and the storage, so that the bidirectional interaction between the power grid and the user is realized. The controllable and adjustable load, source and storage coordination control micro-grid for converting different energy sources is stable, the diversified coupling of different energy source forms such as source, load and storage is improved, clean energy is consumed in situ to the maximum extent, the energy utilization rate is improved, and the energy cost is reduced.

Description

Intelligent response system and method for user side direct current micro-grid
Technical Field
The invention belongs to the field of new energy and power demand side response, and particularly relates to a user side direct current micro-grid intelligent response system and method, and a ubiquitous power internet of things energy management terminal technical method.
Background
Clean energy represented by wind and light is well developed under policy support, but the consumption problem of the operation of a power grid caused by the fluctuation and randomness of the clean energy restricts the scale of the power grid connected with the power grid, and the waste of resources is caused by wind and light discarding, which is a main contradiction of the clean energy development.
Compared with an alternating-current micro-grid, the direct-current micro-grid can receive clean energy sources such as wind, light and the like more efficiently and reliably, is easy to coordinate and control, and can realize power balance of the micro-source and the load by controlling the stability of the voltage of the direct-current bus.
At present, a voltage layering control strategy is mainly adopted in the direct-current micro-grid, and the working modes of all interface converters in the system are determined by detecting the variation of the busbar voltage of the direct-current micro-grid, so that the stable operation of the direct-current micro-grid is realized. However, the voltage layering control strategy cannot realize flexible and accurate power distribution among the interface converters, and needs to be further improved.
In the voltage layering control strategy, only when the micro-grid cannot maintain low-voltage stable operation, a low-voltage load shedding measure is adopted, and in the normal operation, the continuous adjustable power and controllable load do not participate in the voltage stable operation control of the micro-grid, and in addition, the voltage layering control strategy does not consider the problem of coupling of clean energy and other energy, so that the on-site absorption of the clean energy maximization is not realized.
At present, related researches on demand response are mainly focused on scheduling mechanisms and pricing strategies, user loads have coupling characteristics, and a control method related to a demand response mode cannot be directly applied to an end user direct current micro-grid.
Disclosure of Invention
Aiming at the defects and improvement requirements in the prior art, the invention provides an intelligent response system and method for a user side direct current micro-grid. The aim is to realize the aim of the intelligent response of the upper computer energy optimization scheme on the user side.
The invention is realized by the following technical scheme:
The intelligent response system of the direct-current micro-grid at the user side comprises the direct-current micro-grid and an intelligent energy manager and is in wireless interconnection with an upper computer of a power distribution network, wherein the direct-current micro-grid comprises: direct current bus, power supply, load and energy storage; wherein, the power supply, the load and the energy storage are provided with interface converters; the power supply, the load and the energy storage are respectively connected with the direct current bus through the interface converter; the energy intelligent manager is connected with a power supply, a load and energy storage through a communication bus and is in wireless interconnection with the upper computer; the upper computer calculates or formulates an energy optimal configuration scheme of the ubiquitous power Internet of things, and transmits the energy optimal configuration scheme to the energy intelligent manager through wireless transmission.
The interface converter comprises a DC/DC or DC/AC controllable interface converter; the upper computer is a power distribution network management user system.
An intelligent response method for a user side direct current micro-network comprises the following steps:
step 1, receiving an upper computer energy optimization scheme, and improving a direct current micro-grid voltage layering control strategy;
Step 2, changing a control strategy of a grid-side interface converter and an energy storage interface converter to fixedly occupy a voltage layer near rated voltage;
and 3, configuring voltage layers of interface converters of different devices, realizing the distribution of power among the interface converters, enhancing the coupling of clean energy and different energy forms at the demand side, and intelligently responding to an upper energy optimizing scheme.
The application range of the voltage layering control strategy of the direct current micro-grid in the step 1 is that a user and a building are taken as end users of an energy unit; the energy unit is a carrier which takes a user side direct current micro-grid as energy exchange; the user side direct current micro-grid is formed by combining energy storage modes of different types of power supplies, loads with different electric energy conversion modes and different energy storage modes; the loads of different electric energy conversion forms are continuously controllable and can be enhanced to be coupled with other energy sources through the interface converter.
The receiving upper computer energy optimizing scheme is characterized in that a user side direct current micro-grid power supply is divided, load and energy storage can be continuously regulated and controlled, and the response sequence of the power supply, the load and the energy storage interface converter is shortened.
The response sequence of the source, load and storage interface converters in the upper computer energy optimization scheme is received, the response sequence is discharged under the condition that the given value of the power of the interface converter in the upper computer energy optimization scheme is met, and the response of the given value of the power of the interface converter which is met preferentially is prioritized; the power set value of the sagging control characteristic of each interface converter is a power distribution value in an optimization scheme; the response of the interface converter power set value which is preferably satisfied is to improve a DC micro-grid voltage layering control strategy, and the current flows out of a DC bus interface converter to form a group, namely 'load', which comprises a power interface converter which is used for transmitting power to a power supply through a bus, an energy storage interface converter which works in a charging state and a load interface converter; dividing response sequences according to the power distribution sequences in the optimal distribution scheme, and giving priority to the distribution responses; the method comprises the steps that current flows into a direct current bus interface converter to form a group, namely a source for short, wherein the source comprises a power interface converter for supplying power to a bus by a power supply, an energy storage interface converter working in a discharging state and a clean energy interface converter; and (3) sequentially meeting the condition that the power of the 'load' group converters is ordered from high to low, and inserting the 'source' group converters into the ordering of the 'load' group converters.
The response sequence of the source, load and storage interface converters in the upper computer energy receiving optimization scheme is within the voltage range of (0.90-1.10) pu, voltage layers are divided according to the total number of the source and the load and the reserved boundary number, and the calculation formula is as follows:
n＝[(1.1-0.9)/(d+k+r)]
wherein n is the number of division layers, d is the number of 'source' group converters, k is the number of 'load' group converters, r is the number of reserved voltage layers, and [ (] is a rounding function; the division of the layers is shown in a voltage hierarchy table:
Voltage layering table
The table above is bounded by a nominal value of 1pu, with higher than 1pu being the "load" side, lower than 1pu being the "source" side, Δn being the differential pressure of the hierarchy, and variable.
In the step 2, a control strategy that a network side interface converter and an energy storage interface converter fixedly occupy voltage layers near rated voltage is changed, wherein each voltage layer comprises an interface converter, the interface converters are divided into two groups of a source and a load, the load group interface converters are ordered, and response sequences are divided; the dividing principle is as follows: in the optimized allocation scheme, the response sequence is discharged under the condition of meeting the power given value of the interface converter, namely, the response sequence is divided according to the power allocation sequence in the optimized scheme, the priority allocation response is priority, the level is high, and the method sequentially determines the priority allocation response comprises the following steps:
Step (1) determining the highest level; if the micro-grid energy is on the internet preferentially, distributing the power converter to the 1 st layer; if the micro-grid energy source charges the energy storage preferentially, distributing the energy storage converter to a layer 1; the energy of the micro-grid is preferentially consumed in situ, and the load converter is distributed to the layer 1;
Step (2), determining the next layer, namely the layer 2, in the residual current transformer, wherein the principle is unchanged; assuming that the energy storage converter is distributed to the layer 1, and the remaining power supply converter and the load converter; if the residual power meeting the power given value of the energy storage converter is on the internet preferentially, distributing the power supply converter to the layer 2; if the residual power is preferentially consumed in situ, distributing the load converter to the layer 2;
and (3) repeating the step (2) until the last 'on-load' side interface converter is set.
Further, sequencing the source side interface converters and dividing priorities; the voltage amplitude of the selected 'source' side voltage layer of the same bidirectional interface converter is necessarily lower than that of the 'load' side voltage layer; for a source side interface converter participating in the power control of the load side, inserting the source side interface converter into a voltage layer with one layer higher than the voltage amplitude of a controlled interface converter under the condition that the power of a group converter with priority level from high to low is sequentially met, and inserting the source group converter into the sequencing of the load group converter; the method of the source side interface converter which does not participate in the power regulation of the load side is the same as that of the load side, and the voltage reduction sequencing is started from the first layer, namely the k+1st layer, of the immediately adjacent load side.
The voltage layer where the interface converters of different devices are arranged in the step 3, so that the distribution of power among the interface converters is realized, the coupling of clean energy and different energy forms at the demand side is enhanced, and the intelligent response upper energy optimizing scheme comprises the following steps:
Setting interface control equipment voltage and power set values according to a voltage layer where a source, a load and a storage are located, adopting droop control, wherein a droop control curve is expressed as:
udc＝udc.H-δidc
δ＝(udc.H-udc.L)/idc.set
idc.set＝Pdc.set/udc
Wherein u dc is the given value of the voltage of the interface equipment, and u dc.H、udc.L is the upper limit and the lower limit of the voltage amplitude interval in the voltage level corresponding table; delta is a sagging coefficient, a power given value in a P dc.set energy optimization distribution scheme, and i dc.set is an interface equipment current given value; i dc is the interface device current value.
Step (2) normally operating the direct current micro-grid, wherein the direct current micro-grid is controlled by an interface converter corresponding to the interval where the bus voltage is positioned, and operates with the droop characteristic of u dc＝udc.H-δidc, so that the power balance in the system is ensured; if the running power of the interval interface converter is smaller than the P dc.set given value, maintaining the current running mode unchanged; if the running power of the interval interface converter is greater than the given value of P dc.set, the interval interface converter is changed into a constant power P dc.set (current limiting) running mode, the voltage of the micro-grid is transited to the next interval, and the micro-grid voltage is controlled by the interface converter corresponding to the interval; at least one voltage sag characteristic converter is arranged at each voltage interval of the direct current micro-grid to control direct current voltage, and natural smooth switching of voltage stabilization control among different interface converters is realized;
Step (3) changing the source, the load, the storage and transportation states and the upper computer energy optimization scheme, resetting the response sequence, and switching the reset response sequence from high to low in sequence with the original response sequence;
And adopting a ramp function to realize translation switching among different response sequences, translating a constant u dc.H in the droop characteristic of u dc＝udc.H-δidc to a voltage upper limit value of a reset corresponding section, wherein the translation function is as follows:
udc.Hx＝udc.Ha-st
s＝(udc.Ha-udc.Hb)/tset；
Wherein: u dc.Hx is a translation given value, u dc.Ha、udc.Hb is an original response sequence, and the upper limit of a voltage amplitude interval corresponding to the response sequence is reset; s is the slope of the ramp function, t is the translational switching time, and t set switching time is set;
after translation, modifying a sagging coefficient delta and a power set value P dc.set in an energy optimizing and distributing scheme according to a source, load and storage running state and an upper computer energy optimizing scheme; by responding to different permutation and combination of sequences and stably switching between different combinations, the accurate distribution of the power of the required interface converter is realized, the voltage layering control function is expanded, and the purpose of energy optimization is achieved.
The invention has the following advantages and beneficial effects:
According to the invention, through setting the response sequence of the interface converters, the voltage layering control fixed working mode of the direct-current micro-grid is changed, the network side interface converter is the 1 st layer, the storage battery interface converter is the 2 nd layer and the like; therefore, the power values of the converter at each interface can be flexibly set and accurately distributed, so that the energy optimization distribution scheme of the upper computer can be implemented.
The invention abandons the layered control work switching mode of the direct-current micro-grid voltage, takes the direct-current bus voltage as an information carrier and matches the sagging control characteristic of each voltage layer only interface converter, and the adjacent interface converters do not need to increase hysteresis loops, thus realizing stable and seamless switching of micro-grid stable control; and the smooth switching between networking and island states is realized by different arrangement and combination of response sequences.
According to the invention, the response sequence is different, the energy flow direction and conversion form are different, and the clean energy which cannot be accepted by the power grid is converted into other energy to the maximum extent through the coordination control of the controllable and adjustable interface converters for converting different energy, so that the in-situ absorption capacity of the clean energy is further improved.
The voltage layering control function is expanded through different arrangement and combination of response sequences. For example, clean energy constant power surfing, maximized energy reserve at the user side before power failure of the power grid planning and the like are adopted, so that convenience is brought to the user, and energy waste is reduced.
The ubiquitous electric power internet of things conforms to the new trend of current energy development and consumption, can strengthen the coupling of electric power and other energy sources, improves the comprehensive utilization rate of the energy sources, reduces the energy consumption cost of the whole society, and builds the comprehensive energy service intelligent ecological platform. The platform construction requires customer response to achieve a value closed loop. Particularly, the ubiquitous electric power Internet of things surrounding a user side searches for diverse coupling of clean energy and different energy forms such as cold, heat, electricity and water at a demand side, executes a demand response instruction, realizes bidirectional interaction between a power grid and a user, and needs an intelligent response method at the user side.
Drawings
In order that those of ordinary skill in the art will readily understand and practice the invention, a further understanding of the invention will be provided by reference to the following drawings, which illustrate exemplary embodiments of the invention and their description, and are not to be construed as unduly limiting the invention.
FIG. 1 is a schematic diagram of a DC micro-grid structure at a user side of the present invention;
fig. 2 is a schematic diagram of a typical 220V building dc microgrid end user architecture that contains multiple types of loads.
In the figure: the intelligent energy management system comprises an intelligent energy manager 1, a communication bus 2, a direct current bus 3, a power supply 4, a load 5, energy storage 6, an interface converter 7, an upper computer 8 and a photovoltaic 9.
Detailed Description
Embodiments of the invention are described in detail below with reference to the attached drawings, which may be implemented in a number of different ways as defined and covered by the claims. It is specifically stated that the following description is merely illustrative of the principles and examples in nature and is in no way intended to limit the disclosure, its application, or uses. The relative arrangement of the components and steps set forth in the embodiments, as well as the numerical expressions and numerical values, are not limiting the scope of the present disclosure unless it is specifically stated otherwise. In addition, techniques, methods, and apparatus known to those of skill in the art may not be discussed in detail, but are intended to be part of the specification where appropriate.
Example 1
The invention relates to an intelligent response system and method for a user side direct current micro-grid, which are used for receiving an upper energy optimization scheme, improving a direct current micro-grid voltage layering control strategy by dividing a user side direct current micro-grid power supply, continuously regulating and controlling load and energy storage response sequence, changing a control strategy of a grid side interface converter and an energy storage interface converter which fixedly occupy voltage layers near rated voltage, namely, 1 and 2 layers, flexibly configuring voltage layers of interface converters of different devices, realizing flexible and accurate distribution of power among the interface converters, enhancing coupling of clean energy and different energy forms at a demand side, and thus intelligently responding to the upper energy optimization scheme.
The system of the invention comprises a direct current micro-grid and an intelligent manager thereof, and is in wireless interconnection with an upper computer of a power distribution network, wherein the direct current micro-grid comprises: the direct current bus 3, the power supply 4, the load 5 and the energy storage 6. Wherein, the power supply 4, the load 5 and the energy storage 6 all comprise an interface converter 7; the power supply 4, the load 5 and the energy storage 6 are respectively connected with the direct current bus 3 through the interface converter 7; the energy intelligent manager 1 is connected with a power supply 4, a load 5 and an energy storage 6 through a communication bus 2, is in wireless interconnection with an upper computer 8, receives an optimal configuration scheme of the power distribution network, and patrols the state of the direct-current micro-grid equipment.
The upper computer is a generic name of a power distribution network management user system, and the upper computer 8 calculates or formulates an energy optimal configuration scheme of the ubiquitous power internet of things and transmits the energy optimal configuration scheme to the energy intelligent manager 1 through wireless transmission.
The interface converter 7 comprises a DC/DC or DC/AC controllable interface converter.
The invention discloses an intelligent response method of a direct-current micro-grid at a user side, which is realized by improving a voltage layering control strategy of the direct-current micro-grid, and has the application range of being an end user taking a user and a building as energy units. The energy unit is a carrier which takes a user side direct current micro-grid as energy exchange; the user side direct current micro-grid is formed by combining different kinds of power supplies, loads in different electric energy conversion modes, energy storage modes in different energy storage modes and the like. The loads of different electric energy conversion forms are continuously controllable and can be enhanced to be coupled with other energy sources through the interface converter.
The invention discloses an intelligent response method of a user side direct current micro-grid, which specifically comprises the following steps:
step 1, receiving an upper computer energy optimization scheme, and improving a direct current micro-grid voltage layering control strategy;
Step 2, changing a control strategy of a grid-side interface converter and an energy storage interface converter to fixedly occupy a voltage layer near rated voltage;
and 3, configuring voltage layers of interface converters of different devices, realizing the distribution of power among the interface converters, enhancing the coupling of clean energy and different energy forms at the demand side, and intelligently responding to an upper energy optimizing scheme.
In the step 1, the upper computer energy receiving optimization scheme is that the response sequence of a direct current micro-grid power supply at the user side, a load capable of being continuously regulated and controlled, energy storage, short for the source, the load and the storage interface converter is divided. The voltage layering control strategy of the direct current micro-grid is improved, the flexible and accurate distribution of power among the interface converters is realized, the continuously adjustable and controllable load response sequence is changed, the coupling between clean energy and different energy forms at the demand side is enhanced, and the intelligent response upper-level energy optimization scheme is realized.
And the response sequence of the source, load and storage interface converters is discharged under the condition of meeting the given power value of the interface converter in the optimization scheme of the upper potential energy machine, and the response of the given power value of the interface converter which is preferably met is preferential.
And the power set value of the droop control characteristic of each interface converter is a power distribution value in an optimization scheme.
The response of the interface converter power given value which is preferably satisfied is preferably to improve the voltage layering control strategy of the direct current micro-grid. The current flowing out DC bus interface converters are a group, namely a load for short, and comprise a power interface converter which is positioned in a bus and transmits power to a power supply, an energy storage interface converter which works in a charging state and a load interface converter. And dividing the response sequence according to the power distribution sequence in the optimal distribution scheme, wherein the priority distribution response is priority. The current flows into the DC bus interface converters to form a group, namely a source, the source comprises a power interface converter for supplying power to the bus, and the power interface converter works in a discharging state. And (3) sequentially meeting the condition that the power of the 'load' group converters is ordered from high to low, and inserting the 'source' group converters into the ordering of the 'load' group converters.
In the voltage range of (0.90-1.10) pu, dividing voltage layers according to the total number of 'sources', 'carriers' and the reserved boundary number, wherein the calculation formula is as follows:
n＝[(1.1-0.9)/(d+k+r)]
Wherein n is the number of division layers, d is the number of 'source' group converters, k is the number of 'load' group converters, r is the number of reserved voltage layers, and [ (] is a rounding function. The division of the layers is shown in a voltage hierarchy table:
Voltage layering table
The upper table is bounded by a rated value 1pu, the higher 1pu is the "load" side, the lower 1pu is the "source" side, deltan is the level pressure difference, which can be a variable, and the voltage difference of the layer where the rated voltage is located can be properly reduced for small voltage fluctuation during normal operation.
And in the step 2, a control strategy that the grid-side interface converter and the energy storage interface converter occupy a voltage layer near rated voltage is changed. Each voltage layer only comprises one interface converter, the interface converters are divided into two groups of source and carrier according to an energy optimization scheme, the carrier group interface converters are firstly ordered, and response sequences are divided. The dividing principle is as follows: and in the optimal allocation scheme, the response sequence is discharged under the condition of meeting the power given value of the interface converter, namely, the response sequence is divided according to the power allocation sequence in the optimal allocation scheme, the priority allocation response is prioritized, the level is high, and the order is determined. The specific process comprises the following steps:
Step (1) first determines the highest level. If the micro-grid energy is on the internet preferentially, distributing the power converter to the 1 st layer; if the micro-grid energy source charges the energy storage preferentially, distributing the energy storage converter to a layer 1; the energy of the micro-grid is preferentially consumed in situ, and the load converter is distributed to the layer 1;
And (2) determining the next layer, namely layer 2, in the residual current transformer, wherein the principle is unchanged. It is assumed that the energy storage converter has been allocated layer 1, the remaining power converters, the load converters. If the residual power meeting the power given value of the energy storage converter is on the internet preferentially, distributing the power supply converter to the layer 2; if the residual power is preferentially consumed in situ, distributing the load converter to the layer 2;
and (3) repeating the step (2) until the last 'on-load' side interface converter is set.
Further, the source side interface converters are ordered and prioritized. The dividing principle is as follows: the voltage amplitude of the selected 'source' side voltage layer of the same bidirectional interface converter is necessarily lower than that of the 'load' side voltage layer; for the source side interface converter participating in the power control of the load side, on the condition that the power of the group converter with the priority level from high to low is sequentially met, the source side interface converter can be inserted into a voltage layer with one layer higher than the voltage amplitude of the controlled interface converter, and the source group converter is inserted into the sequencing of the load group converter; the method of the source side interface converter which does not participate in the power regulation of the load side is the same as that of the load side, and the voltage reduction sequencing is started from the first layer, namely the k+1st layer, of the immediately adjacent load side.
And 3, configuring voltage layers where the interface converters of different devices are positioned, realizing the distribution of power among the interface converters, enhancing the coupling of clean energy and different energy forms at the demand side, and intelligently responding to an upper energy optimizing scheme. Setting interface control equipment voltage and power set values according to a voltage layer where a source, a load and a storage are located, adopting droop control, wherein a droop control curve is expressed as:
udc＝udc.H-δidc
δ＝(udc.H-udc.L)/idc.set
idc.set＝Pdc.set/udc
Wherein u dc is the given value of the voltage of the interface equipment, and u dc.H、udc.L is the upper limit and the lower limit of the voltage amplitude interval in the voltage level corresponding table; delta is a droop coefficient, a power given value in a P dc.set energy optimization distribution scheme, i dc.set is an interface device current given value, and i dc is an interface device current value.
Further, the direct current micro-grid is normally operated, and is controlled by an interface converter corresponding to the interval where the bus voltage is located, so that the direct current micro-grid operates with the droop characteristic of u dc＝udc.H-δidc, and the power balance in the system is ensured. If the running power of the interval interface converter is smaller than the P dc.set given value, maintaining the current running mode unchanged; if the operation power of the interval interface converter is greater than the given value of P dc.set, the interval interface converter is changed into a constant power P dc.set (current limiting) operation mode, the voltage of the micro-grid is transited to the next interval, and the micro-grid voltage is controlled by the interface converter corresponding to the interval. Therefore, each voltage interval of the direct current micro-grid is provided with at least one voltage sag characteristic converter for controlling direct current voltage, and natural smooth switching of voltage stabilization control among different interface converters is realized;
Further, the response sequence is reset by changing the optimization schemes of the source, the load, the storage and transportation states and the host computer energy.
Further, the reset response sequence is switched from high to low to the original response sequence. And adopting a ramp function to realize translation switching among different response sequences, namely translating a constant u dc.H in the droop characteristic of u dc＝udc.H-δidc to a voltage upper limit value of a reset corresponding section, wherein the translation function is as follows:
udc.Hx＝udc.Ha-st
s＝(udc.Ha-udc.Hb)/tset；
Wherein: u dc.Hx is a translation given value, u dc.Ha、udc.Hb is an original response sequence, and the upper limit of a voltage amplitude interval corresponding to the response sequence is reset; s is the slope of the ramp function, t is the transition switching time, and t set switching time is set.
Further, after translation, according to the source, load, storage running state and the upper computer energy optimization scheme, the droop coefficient delta and the power set point P dc.set in the energy optimization distribution scheme are modified.
By responding to different permutation and combination of sequences and stably switching between different combinations, the accurate distribution of the power of the required interface converter is realized, the voltage layering control function is expanded, and the purpose of energy optimization is achieved.
The energy optimization scheme is realized by adding controllable and adjustable loads into stable control of a micro-grid, changing load response sequence, adjusting the coupling degree of clean energy and other energy, and improving the diversified coupling of different energy forms such as sources, loads, storages and the like.
Further, the source, the load and the storage response sequence are different, and the energy flow direction and the conversion form are different. By adjusting the load response sequence, the quantity of other energy forms converted by the electric energy can be adjusted, the diversified coupling of different energy forms on the clean energy and the demand side is realized, and the intelligent response of the energy is achieved.
Further, once the response sequence is determined, the converters operate independently, do not need to communicate with each other, and are controlled in a decentralized manner.
Further, in order to operate the clean energy source in the power supply in a maximum power tracking Mode (MPPT), the clean energy source is set at the highest voltage amplitude layer, and when the voltage of the direct current micro-grid exceeds the set voltage, the power is reduced.
Example 2
As shown in fig. 2, fig. 2 is a schematic diagram of a typical 220V building dc microgrid end user structure containing multiple types of loads. Wherein: the direct current micro-grid consists of a direct current bus 3, commercial power, a load 5, a storage battery pack and a photovoltaic 9. Wherein, the power supply 4 selects the commercial power, and the energy storage 6 selects the storage battery. To fully utilize the photovoltaic, the photovoltaic is listed separately from the power source.
Wherein, the commercial power, the load 5, the storage battery pack and the photovoltaic 9 all comprise a DC/DC or DC/AC interface converter 7; the commercial power, the load 5, the storage battery pack and the photovoltaic 9 are respectively connected with the direct current bus 3 through the interface converter 7; the intelligent energy manager 1 is connected with a commercial power, a load 5, a storage battery pack and a photovoltaic 9 through a communication bus 2, is in wireless interconnection with an upper computer 8, receives an optimal configuration scheme of a power distribution network, and patrols the state of direct-current micro-grid equipment. The load 5 comprises a controllable load variable-frequency heater, a television, a computer, an electric kettle, an electric cooker and an uncontrollable load. Specific parameters are as follows:
User parameter table
The upper computer calculates or formulates an energy optimal configuration scheme of the ubiquitous power Internet of things, and transmits the energy optimal configuration scheme to the energy intelligent manager through wireless transmission.
The specific energy optimizing and distributing scheme is as follows: the user side mains supply power generation and internet surfing power does not exceed 4kW of power, and the battery pack battery state soc=60%.
After the energy intelligent manager receives the scheme, the power supply, the load, the storage battery and the photovoltaic are divided into two groups of source and load according to the direction of the current flowing in and out of the direct current bus of the interface converter:
"Source": commercial power Rectifying device , a storage battery Discharge of electric power and photovoltaic;
"carrier": commercial power Inversion method , load, battery Charging method ;
According to the total number of "sources" and "carriers" of 6 and 1 voltage layer left at the DC voltage boundary, the voltage is divided into 7 layers within the range of (0.90-1.10) pu. In order to reduce voltage fluctuation during normal operation, the voltage level difference of a layer where rated voltage is located is small, and referring to a voltage layering control strategy of a direct current micro-grid, the division of the layers is shown as a voltage layering table:
Voltage layering table
In order to maximally utilize clean energy, the device operates in an MPPT mode, and the 4 th layer of the highest voltage amplitude is fixedly distributed to the photovoltaic;
Further, the "on-load" group response order is divided. According to the scheme, photovoltaic is on the net preferentially, the net side commercial power Inversion method is set to be the 1 st layer, and the power P dc.set =4 kW; battery pack Charging method battery state soc=60%, to maintain photovoltaic preferential internet access, the remaining power is preferentially stored in the battery, and therefore, when battery pack Charging method is set to layer 2, the load is set to layer 3.
The "source" group is prioritized. For maximum utilization of photovoltaic, it has been fixedly set as a "source" layer 4; for the "source" side battery pack Discharge of electric power that participates in the "on-load" side power control, if the battery pack Discharge of electric power is inserted into the voltage layer 2 that is one layer higher than the voltage amplitude of the commercial power Inversion method , the "on-load" side battery pack Charging method and the load become the 3 rd and 4 th layers in order, and the commercial power Rectifying device that does not participate in the "on-load" side power adjustment is the 5 th layer. According to the principle that each voltage layer can only comprise one interface converter, because the photovoltaic and the load are the same voltage layer, conflict is generated, and the voltage of the photovoltaic is fixed, the voltage layers of the other 'source' and 'load' groups are extended to the voltage layer with one layer lower voltage amplitude, and the result is shown in the following voltage layering table:
Voltage layering table
According to the photovoltaic, load, storage battery and mains supply layers, setting sagging control curves of each voltage layer:
udc＝udc.H-δidc
δ＝(udc.H-udc.L)/idc.set
idc.set＝Pdc.set/udc
Wherein u dc is the given value of the voltage of the interface equipment, and u dc.H、udc.L is the upper limit and the lower limit of the voltage amplitude interval in the priority corresponding table; delta is a droop coefficient, and the rest is the limiting power of each interface device except the commercial power Inversion method Pdc.set which is limiting power of 4 kW. i dc.set is the interface device current setpoint. i dc is the interface device current value.
The calculation results are shown in the droop control curve table:
Sag control curve table
Note that the data in the table are per-sign values. 220V voltage reference, wherein the power reference is rated power of each interface device
The intelligent response process of the direct current micro-network of the user is as follows:
the method is divided into that the photovoltaic power generation power is smaller than the internet limited power and the photovoltaic power generation power is larger than the internet limited power by 4kW.
Photovoltaic power is less than 4kW of limit power of surfing the net:
When the sum of the discharge power of the photovoltaic inflow micro-grid and the storage battery pack Discharge of electric power is less than or equal to 4kW, the storage battery pack Discharge of electric power operates with the maximum discharge power and constant power, the direct-current micro-grid is controlled to be stable by the sagging characteristic of the mains supply Inversion method , and the voltage of the micro-grid is positioned in a (0.98-1.0) pu interval;
As the power of the photovoltaic inflow micro-grid increases, the voltage of the micro-grid increases, when the sum of the power of the photovoltaic inflow micro-grid and the discharge power of the storage battery pack Discharge of electric power is larger than 4kW, the voltage continues to increase, the micro-grid voltage enters a (1.0-1.02) pu interval, the commercial power Inversion method is changed into 4kW constant power to operate, the storage battery pack Discharge of electric power controls the direct-current micro-grid to be stable under the sagging characteristic, the power output is reduced, and the internet surfing power is maintained to be 4kW;
photovoltaic power is greater than 4kW of limit power of surfing the net:
When the photovoltaic inflow microgrid power continuously increases to be more than 4kW, the discharging power of the storage battery Discharge of electric power is reduced to 0, the voltage of the microgrid continuously increases, the voltage of the microgrid enters a (1.02-1.05) pu interval, the sagging characteristic of the storage battery Charging method in the interval controls the stability of the direct-current microgrid, and the photovoltaic residual power is stored in the storage battery preferentially except for maintaining the internet power to be 4 kW.
When the battery pack Charging method battery state is at SOC >80%, the charge power is limited. When soc=95%, the response sequence is reset by the energy manager according to the battery state at this time. The battery Charging method is lowered to layer 3 and the load is raised to layer 2;
And adopting a slope function to realize translation switching between the storage battery Charging method and different layers of loads. The translation function is as follows:
s＝(udc.Ha-udc.Hb)/tset＝(1.09-1.05)/1＝0.04
udc.Hx＝udc.Ha-st＝1.09-0.04t；
Wherein: u dc.Hx is a translation given value, u dc.Ha、udc.Hb is an original response sequence, and the upper limit of a voltage amplitude interval corresponding to the response sequence is reset; s is the slope of the ramp function, t is the transition switching time, and t set switching time is set.
Shifting the load from layer 3 to layer 2, i.e. shifting the constant u dc.H in the load sag characteristic u dc＝udc.H-δidc from the original u dc.Ha =1.09 pu to u dc.Hb =1.05pu, with a shift switching time t set of 1 second; the energy storage Charging method level operates the same as this.
After the storage battery Charging method and the load are stably switched, the internet power is maintained to be 4kW, and the photovoltaic residual power is converted into other forms of energy sources through a load interface converter. In the interval (1.02-1.05) pu, the load is controlled to be stable by the sagging characteristic, and the coupling degree of the clean energy and other energy can be adjusted by changing the load response sequence.
The implementation process of the embodiment can be seen that by designing the arrangement and combination of different response sequences of the direct current micro-grid interface converters, the direct current micro-grid voltage division control strategy is not only used for stably controlling the micro-grid, but also can realize the accurate distribution of power in the micro-grid interface converters, complete the optimization scheme of the upper computer, ensure that the direct current micro-grid voltage operates in (-95% -105%) pu interval as much as possible, and can control the controllable and adjustable load to be added into the stable control of the micro-grid, so that the clean energy absorbing capacity is further improved.
While the invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and principles of the invention, and it is intended to cover all such modifications, equivalents, and alternatives falling within the scope of the invention.

Claims (5)

1. An intelligent response method for a user side direct current micro-network is characterized by comprising the following steps: the system is realized by using a user side direct current micro-grid intelligent response system, wherein the system comprises a direct current micro-grid and an energy intelligent manager and is in wireless interconnection with a power distribution network upper computer, and the direct current micro-grid comprises: a direct current bus (3), a power supply (4), a load (5) and an energy storage (6); wherein, the power supply (4), the load (5) and the energy storage (6) are respectively provided with an interface converter (7); the power supply (4), the load (5) and the energy storage (6) are respectively connected with the direct current bus (3) through the interface converter (7); the energy intelligent manager (1) is connected with a power supply (4), a load (5) and an energy storage (6) through a communication bus (2) and is in wireless interconnection with an upper computer (8); the upper computer (8) calculates or formulates an energy optimal configuration scheme of the electric power Internet of things, and transmits the energy optimal configuration scheme to the energy intelligent manager (1) through wireless transmission; the interface converter (7) comprises a DC/DC or DC/AC controllable interface converter; the upper computer is a power distribution network management user system; the method comprises the following steps:
Step 1, receiving an upper computer energy optimization scheme, and improving a direct current micro-grid voltage layering control strategy; the application range of the voltage layering control strategy of the direct current micro-grid is that the direct current micro-grid is an end user taking a household and a building as energy units; the energy unit is a carrier which takes a user side direct current micro-grid as energy exchange; the user side direct current micro-grid is formed by combining energy storage modes of different types of power supplies, loads with different electric energy conversion modes and different energy storage modes; the loads in different electric energy conversion modes are continuously adjustable and controllable, and the loads coupled with other energy sources can be enhanced through the interface converter;
step 2, changing the network side interface converter and the energy storage interface converter into a voltage layering control strategy;
Step 3, configuring voltage layers of interface converters of different devices, realizing distribution of power among the interface converters, enhancing coupling of clean energy and different energy forms at a demand side, and intelligently responding to an upper energy optimizing scheme; the receiving upper computer energy optimizing scheme is characterized in that a user side direct current micro-grid power supply is divided, load and energy storage can be continuously regulated and controlled, and the response sequence of a converter is called as a source, a load and a storage interface for short; the response sequence of the source, load and storage interface converters in the upper energy optimization scheme is received, the response sequence is discharged under the condition that the given value of the interface converter power in the upper energy optimization scheme is met, and the response of the given value of the interface converter power which is met preferentially is prioritized; the power set value of the sagging control characteristic of each interface converter is a power distribution value in an optimization scheme; the response of the interface converter power set value which is preferably satisfied is to improve a DC micro-grid voltage layering control strategy, and the current flows out of a DC bus interface converter to form a group, namely 'load', which comprises a power interface converter which is used for transmitting power to a power supply through a bus, an energy storage interface converter which works in a charging state and a load interface converter; dividing response sequences according to the power distribution sequences in the optimal distribution scheme, and giving priority to the distribution responses; the method comprises the steps that current flows into a direct current bus interface converter to form a group, namely a source for short, wherein the source comprises a power interface converter for supplying power to a bus by a power supply, an energy storage interface converter working in a discharging state and a clean energy interface converter; and (3) sequentially meeting the condition that the power of the 'load' group converters is ordered from high to low, and inserting the 'source' group converters into the ordering of the 'load' group converters.
2. The intelligent response method for the direct current micro-network on the user side according to claim 1, wherein the intelligent response method is characterized in that: the response sequence of the source, load and storage interface converters in the upper computer energy receiving optimization scheme is within the voltage range of (0.90-1.10) pu, voltage layers are divided according to the total number of the source and the load and the reserved boundary number, and the calculation formula is as follows:
n＝[(1.1-0.9)/(d+k+r)]
wherein n is the number of division layers, d is the number of 'source' group converters, k is the number of 'load' group converters, r is the number of reserved voltage layers, and [ (] is a rounding function; the division of the layers is shown in a voltage hierarchy table:
Voltage layering table
The table above is bounded by a nominal value of 1pu, with higher than 1pu being the "load" side, lower than 1pu being the "source" side, Δn being the differential pressure of the hierarchy, and variable.
3. The intelligent response method for the direct current micro-network on the user side according to claim 1, wherein the intelligent response method is characterized in that: in the step 2, a control strategy that a network side interface converter and an energy storage interface converter fixedly occupy a voltage layer near rated voltage is changed, wherein the voltage layer comprises an interface converter, the interface converters are divided into a source group and a carrier group, the carrier group interface converters are ordered, and response sequences are divided; the dividing principle is as follows: in the optimized allocation scheme, the response sequence is discharged under the condition of meeting the power given value of the interface converter, namely, the response sequence is divided according to the power allocation sequence in the optimized scheme, the priority allocation response is priority, the level is high, and the method sequentially determines the priority allocation response comprises the following steps:
Step (1) determining the highest level; if the micro-grid energy is on the internet preferentially, distributing the power converter to the 1 st layer; if the micro-grid energy source charges the energy storage preferentially, distributing the energy storage converter to a layer 1; the energy of the micro-grid is preferentially consumed in situ, and the load converter is distributed to the layer 1;
Step (2), determining the next layer, namely the layer 2, in the residual current transformer, wherein the principle is unchanged; assuming that the energy storage converter is distributed to the layer 1, and the remaining power supply converter and the load converter; if the residual power meeting the power given value of the energy storage converter is on the internet preferentially, distributing the power supply converter to the layer 2; if the residual power is preferentially consumed in situ, distributing the load converter to the layer 2;
and (3) repeating the step (2) until the last 'on-load' side interface converter is set.
4. The intelligent response method for the direct-current micro-network on the user side according to claim 3, wherein the intelligent response method is characterized in that: sequencing the source side interface converters and dividing the priority; the voltage amplitude of the selected 'source' side voltage layer of the same bidirectional interface converter is necessarily lower than that of the 'load' side voltage layer; for a source side interface converter participating in the power control of the load side, inserting the source side interface converter into a voltage layer with one layer higher than the voltage amplitude of a controlled interface converter under the condition that the power of a group converter with priority level from high to low is sequentially met, and inserting the source group converter into the sequencing of the load group converter; the method of the source side interface converter which does not participate in the power regulation of the load side is the same as that of the load side, and the voltage reduction sequencing is started from the first layer, namely the k+1st layer, of the immediately adjacent load side.
5. The intelligent response method for the direct current micro-network on the user side according to claim 1, wherein the intelligent response method is characterized in that: the voltage layer where the interface converters of different devices are arranged in the step 3, so that the distribution of power among the interface converters is realized, the coupling of clean energy and different energy forms at the demand side is enhanced, and the intelligent response upper energy optimizing scheme comprises the following steps:
Setting interface control equipment voltage and power set values according to a voltage layer where a source, a load and a storage are located, adopting droop control, wherein a droop control curve is expressed as:
udc＝udc.H-δidc
δ＝(udc.H-udc.L)/idc.set
idc.set＝Pdc.set/udc
Wherein u dc is the given value of the voltage of the interface equipment, and u dc.H、udc.L is the upper limit and the lower limit of the voltage amplitude interval in the voltage level corresponding table; delta is a sagging coefficient, a power given value in a P dc.set energy optimization distribution scheme, and i dc.set is an interface equipment current given value; i dc is the interface device current value;
Step (2) normally operating the direct current micro-grid, wherein the direct current micro-grid is controlled by an interface converter corresponding to the interval where the bus voltage is positioned, and operates with the droop characteristic of u dc＝udc.H-δidc, so that the power balance in the system is ensured; if the running power of the interval interface converter is smaller than the P dc.set given value, maintaining the current running mode unchanged; if the running power of the interval interface converter is greater than the given value of P dc.set, changing the interval interface converter into a constant power P dc.set current limiting running mode, and controlling the micro-grid voltage to be transited to the next interval by the interface converter corresponding to the interval; at least one voltage sag characteristic converter is arranged at each voltage interval of the direct current micro-grid to control direct current voltage, and natural smooth switching of voltage stabilization control among different interface converters is realized;
Step (3) changing the source, the load, the storage and transportation states and the upper computer energy optimization scheme, resetting the response sequence, and switching the reset response sequence from high to low in sequence with the original response sequence;
And adopting a ramp function to realize translation switching among different response sequences, translating a constant u dc.H in the droop characteristic of u dc＝udc.H-δidc to a voltage upper limit value of a reset corresponding section, wherein the translation function is as follows:
udc.Hx＝udc.Ha-st
s＝(udc.Ha-udc.Hb)/tset；
Wherein: u dc.Hx is a translation given value, u dc.Ha、udc.Hb is an original response sequence, and the upper limit of a voltage amplitude interval corresponding to the response sequence is reset; s is the slope of the ramp function, t is the translational switching time, and t set switching time is set;
after translation, modifying a sagging coefficient delta and a power set value P dc.set in an energy optimizing and distributing scheme according to a source, load and storage running state and an upper computer energy optimizing scheme; by responding to different permutation and combination of sequences and stably switching between different combinations, the accurate distribution of the power of the required interface converter is realized, the voltage layering control function is expanded, and the purpose of energy optimization is achieved.
CN202010369576.0A 2020-05-05 2020-05-05 Intelligent response system and method for user side direct current micro-grid Active CN111628572B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010369576.0A CN111628572B (en) 2020-05-05 2020-05-05 Intelligent response system and method for user side direct current micro-grid

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010369576.0A CN111628572B (en) 2020-05-05 2020-05-05 Intelligent response system and method for user side direct current micro-grid

Publications (2)

Publication Number Publication Date
CN111628572A CN111628572A (en) 2020-09-04
CN111628572B true CN111628572B (en) 2024-05-03

Family

ID=72258906

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010369576.0A Active CN111628572B (en) 2020-05-05 2020-05-05 Intelligent response system and method for user side direct current micro-grid

Country Status (1)

Country Link
CN (1) CN111628572B (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102931653A (en) * 2012-11-02 2013-02-13 浙江工业大学 Comprehensive coordination control method of wind-solar direct current micro-grid
CN103236712A (en) * 2013-04-08 2013-08-07 嘉兴清源电气科技有限公司 Direct-current micro-grid system and control method thereof
CN105305480A (en) * 2015-07-13 2016-02-03 陕西省地方电力（集团）有限公司 Hybrid energy-storage DC micro grid hierarchical control method
CN106451409A (en) * 2016-12-16 2017-02-22 合肥工业大学 Direct current residence micro-network system and voltage compensation control method

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108155638B (en) * 2016-12-05 2023-12-05 珠海格力电器股份有限公司 Control equipment and control method of direct-current micro-grid and direct-current micro-grid system

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102931653A (en) * 2012-11-02 2013-02-13 浙江工业大学 Comprehensive coordination control method of wind-solar direct current micro-grid
CN103236712A (en) * 2013-04-08 2013-08-07 嘉兴清源电气科技有限公司 Direct-current micro-grid system and control method thereof
CN105305480A (en) * 2015-07-13 2016-02-03 陕西省地方电力（集团）有限公司 Hybrid energy-storage DC micro grid hierarchical control method
CN106451409A (en) * 2016-12-16 2017-02-22 合肥工业大学 Direct current residence micro-network system and voltage compensation control method

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
基于DBS技术的直流微电网分层协调控制策略;赵中田;薛浩晨;邵选英;胡健;李海涛;;山东电力技术(09);全文 *
基于模糊控制的微网平滑切换控制策略的研究;郭权利;《高电压技术》;第41卷(第10期);全文 *
考虑PV-EVs不确定性的孤岛直流微电网控制策略研究;刘媛媛;《信息化研究》;第45卷(第6期);全文 *

Also Published As

Publication number Publication date
CN111628572A (en) 2020-09-04

Similar Documents

Publication Publication Date Title
Ruiz-Cortes et al. Optimal charge/discharge scheduling of batteries in microgrids of prosumers
EP3057192B1 (en) An energy internet and a hierarchical control system and a control method thereof
CN102710013B (en) Park energy-network energy optimizing management system based on microgrids and implementing method thereof
Mohsenian-Rad et al. Towards building an optimal demand response framework for DC distribution networks
CN109149651B (en) Optimal operation method of light storage system considering voltage-regulating auxiliary service income
US11689118B2 (en) Converter with power management system for household users to manage power between different loads including their electric vehicle
CN105680471A (en) Apparatus for the conversion and optimized consumption management of power from renewable sources
CN107508277A (en) A kind of light storage direct-current grid distributed collaboration control method based on uniformity
CN108418244B (en) Multi-microgrid-based flexible interconnection system and energy storage capacity optimization method thereof
CN110601248A (en) Multi-mode coordination control method of annular alternating current-direct current hybrid micro-grid system
CN109066822A (en) A kind of multi-point dispersion formula distribution system dispatching method based on electric power electric transformer
CN113765130A (en) Operation control method of micro-grid
CN108988324A (en) One kind being based on SOC and output power balance control method
CN112653188A (en) Distributed energy system and energy scheduling method
CN113541197A (en) Energy control method and system for low-voltage transformer area flexible-direct interconnection energy-storage-free system
WO2022271102A2 (en) System and method for stabilizing a power distribution network
CN115663791A (en) Intelligent power distribution network multi-target adaptive scheduling method based on time-varying property of operating environment
He et al. A two-layer dynamic voltage regulation strategy for DC distribution networks with distributed energy storages
Švenda et al. Volt var watt optimization in distribution network with high penetration of renewable energy sources and electric vehicles
CN111628572B (en) Intelligent response system and method for user side direct current micro-grid
Ben Belgacem et al. Design and Implementation of Multi-Source and Multi-Consumer Energy‎ Sharing System in Collaborative Smart Microgrid Installation
CN110649590B (en) Energy cooperative control method for networking type direct-current micro-grid
CN106099956B (en) Consider the more microgrid power coordination control methods of single three-phase in the case of distribution scheduling
JP2013162560A (en) Demand and supply adjusting system
Sechilariu et al. A conceptual framework for full optimal operation of a grid-connected DC microgrid

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant