CN111525621B - Distributed coordination control method and system for building group direct current power distribution system - Google Patents

Distributed coordination control method and system for building group direct current power distribution system Download PDF

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CN111525621B
CN111525621B CN202010432113.4A CN202010432113A CN111525621B CN 111525621 B CN111525621 B CN 111525621B CN 202010432113 A CN202010432113 A CN 202010432113A CN 111525621 B CN111525621 B CN 111525621B
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power
direct current
grid
distribution system
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CN111525621A (en
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荣秀婷
朱刘柱
张辉
马静
朱灿
周帆
高廷峰
陈武
程啸
吴润东
李荣冠
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State Grid Anhui Zhongxing Electric Power Design Institute Co ltd
Southeast University
Economic and Technological Research Institute of State Grid Anhui Electric Power Co Ltd
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State Grid Anhui Zhongxing Electric Power Design Institute Co ltd
Southeast University
Economic and Technological Research Institute of State Grid Anhui Electric Power 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
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/008—Circuit arrangements for ac mains or ac distribution networks involving trading of energy or energy transmission rights
    • 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
    • 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
    • H02J3/388—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
    • 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
    • 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
    • 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
    • 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

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  • Supply And Distribution Of Alternating Current (AREA)

Abstract

The invention discloses a distributed coordination control method and a distributed coordination control system for a building group direct current power distribution system, which belong to the technical field of power distribution networks and comprise the following steps: the local controller controls the operation modes of the unit-level controllers corresponding to the constituent units according to a preset rule based on the interval of the direct-current bus voltage, wherein the local controller is pre-built in each constituent unit, and the unit-level controllers at least have three operation modes of constant-voltage control, constant-current control and constant-power control; the centralized controller calculates an optimization result of the preset optimization target, and controls the preset optimization target of the corresponding component unit to reach the optimization result based on the optimization result of the preset optimization target. The invention realizes the comprehensive coordination control of the building group direct current distribution system, has clear control architecture and easy realization, and simultaneously ensures the stability and the economy of the system operation.

Description

Distributed coordination control method and system for building group direct current power distribution system
Technical Field
The invention relates to the technical field of power distribution networks, in particular to a distributed coordination control method and a distributed coordination control system for a building group direct-current power distribution system.
Background
In recent years, with the development and progress of electric energy conversion technology and network communication systems, the proportion of dc loads in typical buildings such as residential houses and public buildings has greatly increased, and in addition to the wide application of power electronic devices and the access of distributed renewable energy, the existing ac power distribution system has been difficult to meet new development requirements. The introduction of the direct current power supply mode improves the performance of the building group distribution power grid from two aspects of equipment production and manufacturing and system operation, not only provides a power utilization environment with high electric energy quality for users, but also can meet the special requirements of high reliability and low loss of sensitive loads such as computers, communication equipment and the like in buildings on the power distribution grid, and is more favorable for safe and efficient operation of flexible loads such as electric vehicles, intelligent household appliances and the like.
The building group direct current power distribution system is used as a new research direction, the main results are limited in the aspects of building group direct current power distribution system composition, structure and stability control, and unified standards and references are lacked. The main research results of the control method comprise two categories of centralized control and distributed control in form, and the two aspects of realizing the stable operation of the building group direct current power distribution system and monitoring and protecting the fault control are achieved in target. The centralized control is based on a communication network of a power distribution system, status information of all the constituent units of the building group direct-current power distribution system is collected to the centralized controller for unified operation, and all control variables are output to corresponding converters to achieve the purposes of system stability, optimized operation and the like. The distributed control method is represented by distributed control based on a direct-current bus voltage signal, determines the working mode of each module based on the direct-current bus voltage, does not need communication, and is simple in controller design. And the stability control realizes that the voltage of the direct current bus is maintained in a normal range when the power state of each component unit of the power distribution network system is between the operation limits. And the fault control realizes the protection of main units in the building group power distribution system after the voltage of the direct current bus is out of control and the recovery of the normal operation state after the fault is cleared.
In practical application, the control method for the building group direct current power distribution system is to combine the power condition of each component unit of the system and the multi-state information such as the voltage state of a direct current bus, and integrate the off-grid state, the grid-connected state, the normal state, the fault state and other various operation states, so as to realize the primary goal of taking the stable operation of the system and realize the control goal of the economic optimization operation of the system on the basis. In addition, because the direct-current power distribution system of the building group has no standard or standard in the current research, the design of the control method of the direct-current power distribution system of the building group can take various direct-current power distribution scenes of the building group, such as residents, businesses, industrial application and the like into consideration.
At present, although some documents discuss the composition, topology and control method of the building group dc power distribution system, the control method and process under multiple operation modes of the building group dc power distribution system are not specifically analyzed and explained, and the research result about the economic optimization operation of the building group dc power distribution system is lacked.
In the patent of three-wire system direct current microgrid system suitable for modern buildings and a control method thereof, which is published under the number of CN102593832B in the invention of China, a composition and a structure of the three-wire system direct current microgrid system suitable for modern buildings and a corresponding control method of a normal state and a large power grid fault state are provided. The method has the advantages of definite control target and simple control process, and can realize long-term stable operation under a specific system structure. But it does not achieve system operation economics optimization and process versatility.
Disclosure of Invention
The invention aims to overcome the defects in the prior art and realize the unification of the stability and the economic operation of a building group direct-current power distribution system and the unification of various operation states and scenes.
In order to achieve the above purpose, the invention adopts a distributed coordination control method for a building group direct current distribution system, wherein each component unit of the building group direct current distribution system is connected with a direct current bus, and the method comprises the following steps:
the local controller controls the operation modes of the unit-level controllers corresponding to the constituent units according to a preset rule based on the interval of the direct-current bus voltage, wherein the local controller is pre-built in each constituent unit, and the unit-level controllers at least have three operation modes of constant-voltage control, constant-current control and constant-power control;
the centralized controller calculates an optimization result of the preset optimization target, and controls the preset optimization target of the corresponding component unit to reach the optimization result based on the optimization result of the preset optimization target.
Further, the interval in which the dc bus voltage is located includes 5 operating intervals: the voltage condition of the direct current bus in the 1 st operation interval is UL1<Udc<UH1The DC bus voltage condition of the 2 nd operation interval is UH1<Udc<UH2And the voltage condition of the direct current bus in the 3 rd running interval is UL2<Udc<UL1And the DC bus voltage condition in the 4 th operation interval is Udc>UH2And the voltage condition of the direct current bus in the 5 th running interval is Udc<UL2(ii) a Wherein, UdcIs a DC bus voltage, UL2、UL1、UH1、UH2Respectively, voltage stratification thresholds.
Further, in the grid-connected operation mode, the local controller controls the operation mode of the unit level controller corresponding to each component unit according to a preset rule based on the interval where the dc bus voltage is located, including:
when the direct current bus voltage is in the 1 st operation interval, taking a port of a grid-connected unit as a loose node, controlling the direct current bus voltage by adopting a droop control method, controlling a power generation unit to be in an MPPT operation mode, and controlling an energy storage unit to be in a non-operation or charge-discharge recovery stage;
when the direct current bus voltage is in the 2 nd operation interval or the 3 rd operation interval, the energy storage unit controls the current power and the voltage variation of the grid-connected unit port to meet the preset droop control relation by adopting a droop control method, and compensates the system deviation power, so that the grid-connected unit port outputs constant limit power; controlling the power generation unit to be in an MPPT operation mode;
when the direct current bus voltage is in the 4 th running interval, controlling a power generation unit to exit an MPPT (maximum power point tracking) working mode, entering a constant voltage running state, instructing a reference voltage to an output port of the unit-level controller, and maintaining the direct current bus voltage;
and when the direct current bus voltage is in the 5 th running interval, controlling the load unit to perform load reduction operation according to the load priority, so that the bus voltage is recovered to the normal running interval.
Further, in the off-grid operation mode, the local controller controls the operation modes of the unit-level controllers corresponding to the constituent units according to a preset rule based on the interval where the dc bus voltage is located, including:
when the direct current bus voltage is in the 1 st running interval and the capacity of the energy storage unit is in a normal state, taking an energy storage unit port as a relaxation node, controlling the direct current bus voltage by adopting a droop control method, and controlling the power generation unit to be in an MPPT running mode; otherwise, the port of the power generation unit is used as a relaxation node to maintain the voltage of the direct current bus, and the energy storage unit is in a non-working or charging and discharging recovery stage;
when the direct current bus voltage is in the 2 nd operation interval or the 3 rd operation interval, taking an energy storage unit port as a relaxation node, maintaining the direct current bus voltage by adopting a droop control method, and controlling a power generation unit to be in an MPPT operation mode;
when the direct current bus voltage is in the 4 th running interval, controlling a power generation unit to exit an MPPT (maximum power point tracking) working mode, entering a constant voltage running state, instructing a reference voltage to an output port of the unit-level controller, and maintaining the direct current bus voltage;
and when the direct current bus voltage is in the 5 th running interval, controlling the load unit to perform load reduction operation according to the load priority, so that the bus voltage is recovered to the normal running interval.
Further, the droop control method determines the equivalent output impedance of the system response unit converter through the adjustment of the droop coefficient, so as to realize the adjustment and power distribution of the output current;
the droop characteristic of the direct current voltage of each component unit port of the building group direct current power distribution system is represented as follows:
Figure BDA0002500953350000041
wherein, UdcOutputting a command reference voltage for the local controller,
Figure BDA0002500953350000042
is a reference voltage reference value, IdcAnd outputting direct current voltage for the composition unit, wherein k is a droop coefficient.
Further, the preset optimization target comprises the realization of lowest operation electric charge of the building group direct current power distribution system and the realization of load constant power control.
Further, when the preset optimization objective is to achieve that the operating electricity charge of the building group dc power distribution system is the lowest, the centralized controller calculates an optimization result of the preset optimization objective, and controls the preset optimization objectives of the corresponding constituent units to reach the optimization result based on the optimization result of the preset optimization objective, including:
constructing an optimized objective function and constraint conditions for the lowest operation electric charge of the building group direct-current power distribution system;
and solving the minimum optimization objective function of the running electric charge by adopting a discrete binary particle swarm optimization algorithm to obtain working state instructions of the load units in the building swarm direct-current power distribution system, and outputting the working state instructions to the unit-level controllers corresponding to the load units to realize the minimum optimization control of the running electric charge of the system.
Further, the operation electricity charge minimum optimization objective function and the constraint conditions are as follows:
the optimization objective function is:
minf1＝Cbuy-Csell
Figure BDA0002500953350000051
Figure BDA0002500953350000052
wherein,
Figure BDA0002500953350000053
the difference between the total system load power and the system generating power at the moment t;
Figure BDA0002500953350000054
buying electricity price to the power grid for the building group;
Figure BDA0002500953350000055
generating and surfing price for photovoltaic power generation units in a building group direct current power distribution system; ppvThe output power sequence of the photovoltaic power generation unit of the system in a set time period; pAThe load is a load which can not be interrupted in a limited time; pBIs an interruptible load; pCIs a non-dispatchable load; cbuyBuying electricity cost for building group DC distribution system; csellSelling electricity earnings for the building group direct current power distribution system;
the constraint conditions are as follows:
and power balance constraint:
Figure BDA0002500953350000056
wherein,
Figure BDA0002500953350000057
outputting power for a grid-connected unit of the system at the time t;
Figure BDA0002500953350000058
outputting power for the photovoltaic power generation unit of the system at the moment t;
Figure BDA0002500953350000059
outputting power for the system energy storage unit at the moment t;
Figure BDA00025009533500000510
the load power can not be interrupted for the time limit of t;
Figure BDA00025009533500000511
interruptible load power for time t;
Figure BDA00025009533500000512
load power can not be scheduled at time t;
and (3) constraint of the electric quantity state of the storage battery pack:
SSOCmin≤SSOC(t)≤SSOCmax
wherein S isSOCminThe minimum value of the state of charge of the storage battery pack; sSOCmaxThe maximum value of the state of charge of the storage battery pack; sSOC(t) is the state of charge of the battery pack at time t;
and (3) transmission power constraint of each component unit of the system:
Figure BDA00025009533500000513
wherein, Pi tThe transmission power of each component unit of the building group direct current power distribution system at the time t is represented;
Figure BDA0002500953350000061
the transmission power lower limit value of the ith component unit of the direct current power distribution system of the current building group is obtained;
Figure BDA0002500953350000062
and the transmission power upper limit value of the ith component unit of the direct current power distribution system of the current building group is obtained.
Further, the speed updating formula of the discrete binary particle swarm optimization algorithm is as follows:
Figure BDA0002500953350000063
wherein,
Figure BDA0002500953350000064
is the velocity of particle i in the kth iteration;
Figure BDA0002500953350000065
is the position of particle i in the kth iteration; omegakIs the inertial weight; r is a random number between (0, 1);
Figure BDA0002500953350000066
the historical optimal extreme value of the particle i in the k iteration is obtained;
Figure BDA0002500953350000067
the optimal extremum of the population of all the particles in the kth iteration is obtained; c. C1、c2Is a learning factor;
the probability that the velocity value is mapped to [0,1] by using the modified sigmoid function as a mapping function represents the chance that the position state of the particle changes:
Figure BDA0002500953350000068
Figure BDA0002500953350000069
wherein,
Figure BDA00025009533500000610
the change threshold of the particle position state in the k +1 th iteration is set;
Figure BDA00025009533500000611
the particle position state at the (k + 1) th iteration.
Further, the inertial weights are updated at each new iteration cycle according to the following equation:
Figure BDA00025009533500000612
wherein, ω ismaxIs the maximum inertial weight; omegaminIs the minimum inertial weight; k is a preset iteration number; k is the current iteration number.
Further, when the preset optimization target is to implement load constant power control, the centralized controller calculates an optimization result of the preset optimization target, and controls the preset optimization targets of the corresponding constituent units to reach the optimization result based on the optimization result of the preset optimization target, including:
the centralized controller receives a control instruction sent by the power system, samples the output power of each component unit of the system, and controls the unit-level controllers corresponding to the load units according to the following relation to realize the load constant power control of the system:
Pes＝PL-Ppv-PG
PG＝C
wherein, PesOutputting power for the system energy storage unit; ppvOutputting power for the system photovoltaic power generation unit; pGOutputting power for a system grid-connected unit; c, establishing a constant power reference value; pLThe total load power of the building group direct current power distribution system is obtained.
On the other hand, a centralized and distributed coordination control system of the building group direct-current power distribution system is adopted, and comprises a centralized controller, unit-level controllers corresponding to all the constituent units of the building group direct-current power distribution system and local controllers arranged in all the constituent units, wherein all the constituent units of the building group direct-current power distribution system are connected with a direct-current bus; the unit-level controllers corresponding to the constituent units receive control instructions output by the local controller to control the corresponding physical quantity reference values given by the response of the direct-current bus port physical quantity tracking control instructions of the corresponding constituent units, so that the constant-voltage, constant-current and constant-power control of the ports of the constituent units is realized; the unit-level controllers corresponding to the constituent units receive the target optimization instructions output by the collection controller so as to control the optimization targets of the corresponding constituent units to achieve the optimization results.
Further, the interval in which the dc bus voltage is located includes 5 operating intervals: the voltage condition of the direct current bus in the 1 st operation interval is UL1<Udc<UH1The DC bus voltage condition of the 2 nd operation interval is UH1<Udc<UH2And the voltage condition of the direct current bus in the 3 rd running interval is UL2<Udc<UL1And the DC bus voltage condition in the 4 th operation interval is Udc>UH2And the voltage condition of the direct current bus in the 5 th running interval is Udc<UL2(ii) a Wherein, UdcIs a DC bus voltage, UL2、UL1、UH1、UH2Respectively, voltage stratification thresholds.
Further, the local controller comprises a grid-connected control module and an off-grid control module, wherein:
the grid-connected control module is used for adjusting the operation mode of the corresponding unit-level controller according to the interval of the direct-current bus voltage in the grid-connected operation mode;
and the off-grid control module is used for adjusting the operation mode of the corresponding unit-level controller according to the interval of the DC bus voltage in the off-grid operation mode.
Further, the grid-connected control module comprises a first grid-connected control unit, a second grid-connected control unit, a third grid-connected control unit, a fourth grid-connected control unit and a fifth grid-connected control unit;
the first grid-connected control unit is used for controlling the direct-current bus voltage by using a droop control method by taking a grid-connected unit port as a loose node when the direct-current bus voltage is in the 1 st operation interval and controlling the power generation unit to be in an MPPT operation mode, and the energy storage unit is in a non-operation or charge-discharge recovery stage
The second grid-connected control unit and the third grid-connected control unit are respectively used for controlling the circulating power and the voltage variation of a grid-connected unit port to meet a preset droop control relation by the energy storage unit by adopting a droop control method when the direct-current bus voltage is in the 2 nd operating interval or the 3 rd operating interval, compensating the system deviation power, enabling the grid-connected unit port to output constant limit power and controlling the power generation unit to be in an MPPT operating mode;
the fourth grid-connected control unit is used for controlling the power generation unit to exit the MPPT working mode and enter a constant voltage running state when the direct current bus voltage is in the 4 th running interval, and instructing a reference voltage to the output port of the unit-level controller to maintain the direct current bus voltage;
and the fifth grid-connected control unit is used for controlling the load unit to perform load reduction operation according to the load priority when the direct-current bus voltage is in the 5 th operation interval so as to restore the bus voltage to a normal operation interval.
Furthermore, the off-grid control module comprises a first off-grid control unit, a second off-grid control unit, a third off-grid control unit, a fourth off-grid control unit and a fifth off-grid control unit;
the first off-grid control unit is used for taking a port of the energy storage unit as a relaxation node when the direct current bus voltage is in the 1 st running interval and the capacity of the energy storage unit is in a normal state, controlling the direct current bus voltage by adopting a droop control method and controlling the power generation unit to be in an MPPT running mode; otherwise, the port of the power generation unit is used as a relaxation node to maintain the voltage of the direct current bus, and the energy storage unit is in a non-working or charging and discharging recovery stage;
the second off-grid control unit and the third off-grid control unit are respectively used for taking a port of the energy storage unit as a loose node when the direct-current bus voltage is in the 2 nd operation interval or the 3 rd operation interval, maintaining the direct-current bus voltage by adopting a droop control method, and controlling the power generation unit to be in an MPPT operation mode;
the fourth off-grid control unit is used for controlling the power generation unit to exit the MPPT working mode and enter a constant voltage running state when the direct current bus voltage is in the 4 th running interval, instructing a reference voltage to an output port of the unit-level controller and maintaining the direct current bus voltage;
and the fifth off-grid control unit is used for controlling the load unit to perform load reduction operation according to the load priority when the direct-current bus voltage is in the 5 th operation interval so as to restore the bus voltage to a normal operation interval.
Further, the preset optimization target comprises the realization of lowest operation electric charge of the building group direct-current power distribution system and the realization of load constant power control, and the centralized controller comprises an electric charge control module and a power control module;
the electric charge control module comprises a function construction unit and an electric charge minimum optimization unit;
the function construction unit is used for constructing an optimized objective function and constraint conditions for the lowest operation electric charge of the building group direct-current power distribution system;
the lowest electricity charge optimization unit is used for solving the lowest operation electricity charge optimization objective function by adopting a discrete binary particle swarm optimization algorithm to obtain working state instructions of load units in the building group direct-current power distribution system, and outputting the working state instructions to the unit-level controllers corresponding to the load units to realize the lowest operation electricity charge optimization control of the system.
Further, the operation electricity charge minimum optimization objective function and the constraint conditions are as follows:
the optimization objective function is:
minf1＝Cbuy-Csell
Figure BDA0002500953350000091
Figure BDA0002500953350000092
wherein,
Figure BDA0002500953350000093
the difference between the total system load power and the system generating power at the moment t;
Figure BDA0002500953350000094
buying electricity price to the power grid for the building group;
Figure BDA0002500953350000095
generating and surfing price for photovoltaic power generation units in a building group direct current power distribution system; ppvThe output power sequence of the photovoltaic power generation unit of the system in a set time period; pAThe load is a load which can not be interrupted in a limited time; pBIs an interruptible load; pCIs a non-dispatchable load; cbuyBuying electricity cost for building group DC distribution system; csellSelling electricity earnings for the building group direct current power distribution system;
the constraint conditions are as follows:
and power balance constraint:
Figure BDA0002500953350000101
wherein,
Figure BDA0002500953350000102
outputting power for a grid-connected unit of the system at the time t;
Figure BDA0002500953350000103
outputting power for the photovoltaic power generation unit of the system at the moment t;
Figure BDA0002500953350000104
outputting power for the system energy storage unit at the moment t;
Figure BDA0002500953350000105
the load power can not be interrupted for the time limit of t;
Figure BDA0002500953350000106
interruptible load power for time t;
Figure BDA0002500953350000107
load power can not be scheduled at time t;
and (3) constraint of the electric quantity state of the storage battery pack:
SSOCmin≤SSOC(t)≤SSOCmax
wherein S isSOCminThe minimum value of the state of charge of the storage battery pack; sSOCmaxThe maximum value of the state of charge of the storage battery pack; sSOC(t) is the state of charge of the battery pack at time t;
and (3) transmission power constraint of each component unit of the system:
Figure BDA0002500953350000108
wherein, Pi tThe transmission power of each component unit of the building group direct current power distribution system at the time t is represented;
Figure BDA0002500953350000109
the transmission power lower limit value of the ith component unit of the direct current power distribution system of the current building group is obtained;
Figure BDA00025009533500001010
and the transmission power upper limit value of the ith component unit of the direct current power distribution system of the current building group is obtained.
Further, the speed updating formula of the discrete binary particle swarm optimization algorithm is as follows:
Figure BDA00025009533500001011
wherein,
Figure BDA00025009533500001012
is the velocity of particle i in the kth iteration;
Figure BDA00025009533500001013
is the position of particle i in the kth iteration; omegakIs the inertial weight; r is a random number between (0, 1);
Figure BDA00025009533500001014
the historical optimal extreme value of the particle i in the k iteration is obtained;
Figure BDA00025009533500001015
the optimal extremum of the population of all the particles in the kth iteration is obtained; c. C1、c2Is a learning factor;
the probability that the velocity value is mapped to [0,1] by using the modified sigmoid function as a mapping function represents the chance that the position state of the particle changes:
Figure BDA0002500953350000111
Figure BDA0002500953350000112
wherein,
Figure BDA0002500953350000113
the change threshold of the particle position state in the k +1 th iteration is set;
Figure BDA0002500953350000114
the particle position state at the (k + 1) th iteration.
Further, the power control module is configured to receive a control instruction sent by the power system, sample output power of each constituent unit of the system, and control the unit-level controller corresponding to the load unit according to the following relationship, so as to implement load constant power control of the system:
Pes＝PL-Ppv-PG
PG＝C
wherein, PesOutputting power for the system energy storage unit; ppvOutputting power for the system photovoltaic power generation unit; pGOutputting power for a system grid-connected unit; c, establishing a constant power reference value; pLThe total load power of the building group direct current power distribution system is obtained.
Compared with the prior art, the invention has the following technical effects: the integrated controller is used as local control, and controls the unit-level controllers corresponding to all the constituent units on the basis of the layered droop control of the direct-current bus voltage, so that the constant-voltage, constant-current and constant-power control of all the constituent units of the building group direct-current power distribution system is realized, and the stable operation of the building group direct-current power distribution system is ensured. Meanwhile, the centralized controller performs sampling calculation on a preset optimization target and a system state, so that economic optimization control of the building group direct-current power distribution system is realized. The invention realizes the comprehensive coordination control of the building group direct current distribution system, has clear control architecture and easy realization, and simultaneously ensures the stability and the economy of the system operation. And the distributed coordination control method architecture combining the local distributed control and the optimized centralized control, the distributed coordination control method architecture and the optimized centralized control method architecture are mutually coordinated and supplemented, and switching is performed through state triggering conditions, so that the comprehensive performance of the control system is greatly improved.
Drawings
The following detailed description of embodiments of the invention refers to the accompanying drawings in which:
FIG. 1 is a flow chart of a distributed coordination control method for a building complex DC distribution system;
FIG. 2 is a diagram of a typical topology of a building complex DC power distribution system;
FIG. 3 is a schematic diagram of distributed coordination control of a building complex DC distribution system;
FIG. 4 is a diagram of a corresponding cell level controller for a photovoltaic power generation cell;
FIG. 5 is a local controller control schematic;
fig. 6 is a control schematic diagram of the centralized controller.
Detailed Description
To further illustrate the features of the present invention, refer to the following detailed description of the invention and the accompanying drawings. The drawings are for reference and illustration purposes only and are not intended to limit the scope of the present disclosure.
As shown in fig. 1, this embodiment discloses a distributed coordination control method for a building complex dc power distribution system, where each component of the building complex dc power distribution system is connected to a dc bus, and the method includes the following steps S1 to S2:
s1, controlling the operation mode of the unit level controller corresponding to each component unit according to a preset rule by the local controller based on the interval of the direct current bus voltage;
the local controller and the unit-level controller are pre-built in each component unit, and the unit-level controller at least has three operation modes of constant voltage control, constant current control and constant power control;
and S2, the centralized controller calculates the optimization result of the preset optimization target, and controls the preset optimization target of the corresponding composition unit to reach the optimization result based on the optimization result of the preset optimization target.
It should be noted that different constituent units of the building group dc power distribution system include, but are not limited to, a grid connection interface unit, a new energy interface unit, an energy storage interface unit, a dc load interface unit, an ac load interface unit, and the like. FIG. 2 shows a typical topology of a building complex DC distribution system, which employs a ring network power supply mode and comprises a DC three-wire distribution line, a photovoltaic power generation unit composed of a photovoltaic array and its corresponding DC/DC converter, a storage battery energy storage unit composed of a storage battery and its corresponding DC/DC converter, a super capacitor energy storage unit composed of a super capacitor bank and its corresponding DC/DC converter, two grid-connected units composed of an AC main network interface and its corresponding AC/DC converter, a plurality of AC load units composed of an AC load and its corresponding AC/DC converter, and a plurality of DC load units composed of a DC load and its corresponding DC/DC converter, wherein each AC load unit and each DC load unit constitute an equivalent unit building load, the set of all equivalent unit building loads is equivalent building group loads. Each component unit of the typical building group direct-current power distribution system is directly connected with a direct-current three-wire system bus.
Further, the interval in which the dc bus voltage is located includes 5 operating intervals: the voltage condition of the direct current bus in the 1 st operation interval is UL1<Udc<UH1The DC bus voltage condition of the 2 nd operation interval is UH1<Udc<UH2And the voltage condition of the direct current bus in the 3 rd running interval is UL2<Udc<UL1And the DC bus voltage condition in the 4 th operation interval is Udc>UH2And the voltage condition of the direct current bus in the 5 th running interval is Udc<UL2(ii) a Wherein, UdcIs a DC bus voltage, UL2、UL1、UH1、UH2Respectively, voltage stratification thresholds.
The local controllers in the constituent units adjust respective working modes according to preset rules according to the interval of the direct-current bus voltage of the building group direct-current power distribution system, so that the direct-current bus voltage stability and the normal operation of the system are realized together, and key equipment and important loads are protected after the system enters an abnormal or fault state.
It should be noted that, as shown in fig. 5, according to the connection relationship between the building group dc distribution network and the ac main network, two basic operation modes of grid connection and grid disconnection exist in the building group dc distribution system, and the control process of the local controller is described below from these two operation modes:
(1) in a grid-connected operation mode:
and when the direct current bus voltage is in the 1 st running interval, taking a grid-connected unit port as a loose node, and maintaining the direct current bus voltage by adopting droop control to realize stable running of the system. At the moment, the photovoltaic power generation unit is in an MPPT operation mode, new energy is consumed to the maximum extent, and the energy storage unit (comprising a storage battery pack and a super capacitor pack) does not work or is in a charge-discharge recovery stage;
when the direct current bus voltage is in the 2 nd operation interval or the 3 rd operation interval, the grid-connected port reaches the power limit at the moment and is in a current-limiting operation state, constant limit power is output, and system deviation power is provided by the energy storage unit. The storage battery pack energy storage unit adopts droop control, the port circulating power and the voltage variation of the storage battery pack energy storage unit meet the preset droop control relation, the super capacitor energy storage unit compensates the high-frequency component of the power difference between the load and the power generation unit (including the grid-connected unit and the photovoltaic unit), the adjustment process is supported, the photovoltaic power generation unit also works in the MPPT operation mode, and new energy is maximally absorbed.
And when the direct current bus voltage is in the 4 th operation interval, the energy storage unit and the grid-connected unit in the building group direct current power distribution system reach the input power limit, are in a current-limiting operation state, and input constant limit power. At the moment, the output power of each power generation unit and each energy storage unit of the power distribution network system is greater than the load demand power, the photovoltaic power generation units exit the MPPT working mode, enter a constant voltage running state, instruct a reference voltage to an output port of the unit-level controller and play a role in maintaining the direct-current bus voltage;
and when the direct current bus voltage is in the 5 th operation interval, the energy storage unit and the grid-connected unit in the building group direct current power distribution system reach the output power limit and are in a current-limiting operation state, and constant limit power is output. At the moment, the output power of each power generation unit and each energy storage unit of the power distribution network system is smaller than the load demand power, the state may be caused by load short-circuit fault or violent change, and the control method performs load reduction operation on the load units according to a set rule and according to the load priority, so that the bus voltage is recovered to a normal operation interval.
(2) In an off-grid operating mode:
when the direct current bus voltage is in the 1 st running interval and the capacity of the energy storage unit is in a normal state, taking an energy storage unit port as a relaxation node, controlling the direct current bus voltage by adopting a droop control method, and controlling the power generation unit to be in an MPPT running mode; otherwise, the port of the power generation unit is used as a relaxation node to maintain the voltage of the direct current bus, and the energy storage unit is in a non-working or charging and discharging recovery stage;
when the direct current bus voltage is in the 2 nd operation interval or the 3 rd operation interval, taking an energy storage unit port as a relaxation node, maintaining the direct current bus voltage by adopting a droop control method, and controlling a power generation unit to be in an MPPT operation mode;
and when the direct current bus voltage is in the 4 th operation interval, the energy storage unit and the grid-connected unit in the building group direct current power distribution system reach the input power limit, are in a current-limiting operation state, and input constant limit power. At the moment, the output power of each power generation unit and each energy storage unit of the power distribution network system is greater than the load demand power, the photovoltaic power generation units exit the MPPT working mode, enter a constant voltage running state, instruct a reference voltage to an output port of the unit-level controller and play a role in maintaining the direct-current bus voltage;
and when the direct current bus voltage is in the 5 th operation interval, the energy storage unit and the grid-connected unit in the building group direct current power distribution system reach the output power limit and are in a current-limiting operation state, and constant limit power is output. At the moment, the output power of each power generation unit and each energy storage unit of the power distribution network system is smaller than the load demand power, the state may be caused by load short-circuit fault or violent change, and the control method performs load reduction operation on the load units according to a set rule and according to the load priority, so that the bus voltage is recovered to a normal operation interval.
It should be noted that the difference between the two in the control method of the power distribution system is mainly reflected in the selection of the slack terminal in the zone 1. When the system is in grid-connected operation, if the transmission power of the grid-connected interface unit is in a reasonable interval, the transmission power is used as a relaxation terminal to undertake bus voltage regulation in the layer 1; when the system is in off-grid operation, if the system has an energy storage unit and the charge state of the storage battery pack is normal, the energy storage unit is used as a relaxation terminal to bear the bus voltage regulation in the layer 1, otherwise, a distributed power supply is used as the relaxation terminal.
In particular, each constituent unit of the system has basic functions such as constant voltage control, constant current control and constant power control, and specific functions adapted to the requirements of system operation stability and economy are provided for specific system constituent units. For example, for photovoltaic power generation units, an MPPT (maximum power tracking) operation mode is provided. On the basis of basic constant voltage control, constant current control and constant power control of the photovoltaic power generation unit, an MPPT algorithm is set, and an output instruction reference voltage of the MPPT algorithm is input into a basic constant voltage control method after passing through a state selector, so that MPPT operation of the photovoltaic power generation unit is realized, and the maximum new energy consumption under a specific scene is ensured. For other constituent units of a building group direct current power distribution system, including but not limited to a grid-connected unit and an energy storage unit, an additional inertia link can be arranged on the basis of a control structure of basic constant voltage control, constant current control and constant power control, so that additional inertia control is realized, and the stability of system operation is further improved from the control angle.
Further, the droop control method determines the equivalent output impedance of the system response unit converter through the adjustment of the droop coefficient, so as to realize the adjustment and power distribution of the output current;
the droop characteristic of the direct current voltage of each component unit port of the building group direct current power distribution system is represented as follows:
Figure BDA0002500953350000161
wherein, UdcOutputting a command reference voltage for the local controller,
Figure BDA0002500953350000162
is a reference voltage reference value, IdcAnd outputting direct current voltage for the composition unit, wherein k is a droop coefficient.
Further, in step S2, the preset optimization objectives include that the dc distribution system of the building group is operated at the lowest power rate and the load constant power control is implemented, the two control objectives are independent of each other, and are implemented by the centralized controller according to a control instruction sent by the power system, where the control instruction may be given by manual triggering or automatic scheduling. The specific control process of the centralized controller is shown in fig. 6:
(1) when the preset optimization target is that the lowest operation electricity charge of the building group direct current power distribution system is realized:
(1-1) firstly establishing a building direct current power distribution system main component unit model: for the load cell model, including: load P with uninterruptible durationAInterruptible load PBNon-dispatchable load PC. For the purpose of accurately controlling the load operation state, a minimum time interval of 0.5h is set, thereby dividing 1 day into 48 operation control intervals. Defining state variables
Figure BDA0002500953350000163
The 2 operating states representing the load of the building group dc distribution system are as follows
Figure BDA0002500953350000164
Wherein t represents an operation control time; n represents the system equivalent load number.
For the photovoltaic power generation unit, the influence of the illumination intensity and the temperature on the power generation power is mainly considered, and the relation formula is as follows
Ppv＝ηSI[1-0.005(T+25)]
Wherein, PpvRepresenting the output power of the photovoltaic power generation unit; eta represents the photoelectric conversion efficiency of the photovoltaic array; s represents the area of the photovoltaic array panel; i represents the illumination intensity; and T represents the operating temperature of the photovoltaic array.
For the storage battery energy storage unit, the change relation of the charge state when the storage battery energy storage unit is charged and discharged in the running state is as follows
Figure BDA0002500953350000171
Wherein S isSOC(t) is the state of charge of the battery pack at time t; crActual charge capacity; cNIs the nominal charge capacity; etachThe charging efficiency of the storage battery pack; etadisIs the discharge efficiency of the battery pack; pch(t) is the charging power of the storage battery pack at the moment t; pdis(t) of accumulator battery at time tDischarge power; Δ t is the operating duration.
(1-2) constructing an optimization objective function and constraint conditions for the lowest operation electric charge of the building group direct current power distribution system, wherein:
the optimization objective function is:
minf1＝Cbuy-Csell
Figure BDA0002500953350000172
Figure BDA0002500953350000173
wherein,
Figure BDA0002500953350000174
the difference between the total system load power and the system generating power at the moment t;
Figure BDA0002500953350000175
buying electricity price to the power grid for the building group;
Figure BDA0002500953350000176
generating and surfing price for photovoltaic power generation units in a building group direct current power distribution system; ppvThe output power sequence of the photovoltaic power generation unit of the system in a set time period; pAThe load is a load which can not be interrupted in a limited time; pBIs an interruptible load; pCIs a non-dispatchable load; cbuyBuying electricity cost for building group DC distribution system; csellSelling electricity earnings for the building group direct current power distribution system;
the constraint conditions are as follows:
and power balance constraint:
Figure BDA0002500953350000177
wherein,
Figure BDA0002500953350000178
outputting power for a grid-connected unit of the system at the time t;
Figure BDA0002500953350000179
outputting power for the photovoltaic power generation unit of the system at the moment t;
Figure BDA00025009533500001710
outputting power for the system energy storage unit at the moment t;
Figure BDA00025009533500001711
the load power can not be interrupted for the time limit of t;
Figure BDA00025009533500001712
interruptible load power for time t;
Figure BDA00025009533500001713
load power can not be scheduled at time t;
and (3) constraint of the electric quantity state of the storage battery pack:
SSOCmin≤SSOC(t)≤SSOCmax
wherein S isSOCminThe minimum value of the state of charge of the storage battery pack; sSOCmaxThe maximum value of the state of charge of the storage battery pack; sSOC(t) is the state of charge of the battery pack at time t;
and (3) transmission power constraint of each component unit of the system:
Figure BDA0002500953350000181
wherein, Pi tThe transmission power of each component unit of the building group direct current power distribution system at the time t is represented;
Figure BDA0002500953350000182
the transmission power lower limit value of the ith component unit of the direct current power distribution system of the current building group is obtained;
Figure BDA0002500953350000183
and the transmission power upper limit value of the ith component unit of the direct current power distribution system of the current building group is obtained.
(1-3) solving the operation electric charge minimum optimization objective function by adopting a discrete binary particle swarm optimization algorithm to obtain a working state instruction of a load unit in the building group direct current power distribution system, and outputting the working state instruction to a unit-level controller corresponding to the load unit to realize operation electric charge minimum optimization control of the system, wherein:
the speed updating formula of the discrete binary particle swarm optimization algorithm is as follows:
Figure BDA0002500953350000184
wherein,
Figure BDA0002500953350000185
is the velocity of particle i in the kth iteration;
Figure BDA0002500953350000186
is the position of particle i in the kth iteration; omegakIs the inertial weight; r is a random number between (0, 1);
Figure BDA0002500953350000187
the historical optimal extreme value of the particle i in the k iteration is obtained;
Figure BDA0002500953350000188
the optimal extremum of the population of all the particles in the kth iteration is obtained; c. C1、c2Is a learning factor;
the probability that the velocity value is mapped to [0,1] by using the modified sigmoid function as a mapping function represents the chance that the position state of the particle changes:
Figure BDA0002500953350000189
Figure BDA00025009533500001810
wherein,
Figure BDA0002500953350000191
the change threshold of the particle position state in the k +1 th iteration is set;
Figure BDA0002500953350000192
the particle position state at the (k + 1) th iteration.
Wherein, the inertial weight is updated at each new iteration cycle according to the following equation:
Figure BDA0002500953350000193
wherein, ω ismaxIs the maximum inertial weight; omegaminIs the minimum inertial weight; k is a preset iteration number; k is the current iteration number.
It should be noted that, in the distribution network level optimization control method of the building group direct current power distribution system, historical and predicted data, electricity prices, unscheduled load power, on-grid electricity prices and adjustable load working power of the photovoltaic power generation units in 48 time periods are used as input parameters, working state instructions of the load units of the system are output through a discrete two-level granulation subgroup optimization algorithm, and the working state instructions are input into the unit level controllers of the corresponding load units under the condition triggered by the optimization control condition, so that the lowest optimization control of the running electricity charge of the system is realized.
(2) When the preset optimization target is to realize load constant power control:
the method comprises the following steps that an integrated controller receives an instruction given by upper-level dispatching of a power system or is manually triggered, and the integrated controller controls unit-level controllers corresponding to load units according to the following relation under the condition that output power of all constituent units of the system is sampled, so that load constant power control of the system is realized:
Pes＝PL-Ppv-PG
PG＝C
wherein, PesOutputting power for the system energy storage unit; ppvOutputting power for the system photovoltaic power generation unit; pGOutputting power for a system grid-connected unit; c, establishing a constant power reference value; pLThe total load power of the building group direct current power distribution system is obtained.
It should be noted that the reference value of the output power of the energy storage unit of the system is output, and the reference value is input into the unit-level controller of the corresponding load unit under the condition triggered by the optimized control condition, so as to realize the load constant power control of the building group direct current power distribution network. The reference value of the output power instruction of the energy storage unit output by the integrated controller is composed of a high-frequency component and a low-frequency component, wherein the high-frequency component is borne by the energy storage unit of the super capacitor bank, and the low-frequency component is borne by the energy storage unit of the storage battery bank, so that the control target is realized.
It should be noted that the coordination control process of the building group dc power distribution system in this embodiment has two basic functions of power control and bus voltage regulation, and the stability control of the building group dc power distribution system can be realized based on the dc bus voltage signal, and the system optimization control is realized on the basis of sampling the real-time status data and the historical reference data, and the control method has a clear architecture and is easy to implement; a distributed coordination control method framework combining local distributed control and optimized centralized control is adopted, the distributed coordination control method framework and the optimized centralized control method framework are mutually coordinated and supplemented, and switching is performed through state triggering conditions, so that the comprehensive performance of a control system is greatly improved; in addition, the scheme has strong universality and further expansion capability, and aiming at the new characteristics and diversity of the building group direct-current power distribution system, the distribution network level optimization control method has wide-range and multi-angle optimization capability, can further accept higher-level scheduling instructions and realize flexible operation.
The embodiment also discloses a distributed coordination control system of the building group direct-current power distribution system, which comprises a centralized controller, unit-level controllers corresponding to all the constituent units of the building group direct-current power distribution system and local controllers arranged in all the constituent units, wherein all the constituent units of the building group direct-current power distribution system are connected with a direct-current three-wire system bus; the unit-level controllers corresponding to the constituent units receive control instructions output by the local controller to control the corresponding physical quantity reference values given by the response of the direct-current bus port physical quantity tracking control instructions of the corresponding constituent units, so that the constant-voltage, constant-current and constant-power control of the ports of the constituent units is realized; the unit-level controllers corresponding to the constituent units receive the target optimization instructions output by the collection controller so as to control the optimization targets of the corresponding constituent units to achieve the optimization results.
According to the topological structure and characteristics of the converter of each constituent unit and the input and output characteristics of ports of different constituent units, the unit-level controller corresponding to each unit is established, and the unit-level controller has three operation modes of constant voltage control, constant current control and constant power control simultaneously based on the requirements of the operation stability and economy of a building group direct current power distribution system. The key structure of the unit-level controller is a typical PI controller (fig. 4 shows the corresponding unit-level controller structure of the photovoltaic power generation unit). The unit-level controllers are used as the basis and the response of the local controller and the centralized controller, and the working modes are switched in real time according to the state instructions output by the local controller and the centralized controller; the local controller and the centralized controller have the same layer and are higher than the unit-level controller, and are used for outputting control instructions to the unit-level controller and realizing the execution states of the local controller and the centralized controller through a state selection structure.
Specifically, as shown in fig. 3, the unit-level controller is configured to perform constant voltage control, constant current control, and constant power control on each constituent unit and the dc bus connection port; after receiving an output control instruction of a local controller or an integrated controller, enabling the direct current bus port physical quantity of each constituent unit to track a corresponding physical quantity reference value given by the response of a superior control instruction, wherein the corresponding physical quantity reference value comprises port voltage, input (output) current and input (output) power, and realizing constant voltage, constant current and constant power control of each constituent unit port of the building group direct current power distribution system.
And transmitting a power optimization result of each component unit of the system obtained by calculation of the integrated controller as a control instruction to a corresponding unit level control method structure for execution on the premise that the optimized operation of the system meets the conditions, so that the operating power condition of each component unit of the system reaches the optimized conditions, and the optimized target and the optimized operation of the building group direct-current power distribution system are realized.
Further, the interval in which the dc bus voltage is located includes 5 operating intervals: the voltage condition of the direct current bus in the 1 st operation interval is UL1<Udc<UH1The DC bus voltage condition of the 2 nd operation interval is UH1<Udc<UH2And the voltage condition of the direct current bus in the 3 rd running interval is UL2<Udc<UL1And the DC bus voltage condition in the 4 th operation interval is Udc>UH2And the voltage condition of the direct current bus in the 5 th running interval is Udc<UL2(ii) a Wherein, UdcIs a DC bus voltage, UL2、UL1、UH1、UH2Respectively, voltage stratification thresholds.
Further, the local controller comprises a grid-connected control module and an off-grid control module, wherein:
the grid-connected control module is used for adjusting the operation mode of the corresponding unit-level controller according to the interval of the direct-current bus voltage in the grid-connected operation mode;
and the off-grid control module is used for adjusting the operation mode of the corresponding unit-level controller according to the interval of the DC bus voltage in the off-grid operation mode.
Further, the grid-connected control module comprises a first grid-connected control unit, a second grid-connected control unit, a third grid-connected control unit, a fourth grid-connected control unit and a fifth grid-connected control unit;
the first grid-connected control unit is used for controlling the direct-current bus voltage by using a droop control method by taking a grid-connected unit port as a loose node when the direct-current bus voltage is in the 1 st operation interval and controlling the power generation unit to be in an MPPT operation mode, and the energy storage unit is in a non-operation or charge-discharge recovery stage
The second grid-connected control unit and the third grid-connected control unit are respectively used for controlling the circulating power and the voltage variation of a grid-connected unit port to meet a preset droop control relation by the energy storage unit by adopting a droop control method when the direct-current bus voltage is in the 2 nd operating interval or the 3 rd operating interval, compensating the system deviation power, enabling the grid-connected unit port to output constant limit power and controlling the power generation unit to be in an MPPT operating mode;
the fourth grid-connected control unit is used for controlling the power generation unit to exit the MPPT working mode and enter a constant voltage running state when the direct current bus voltage is in the 4 th running interval, and instructing a reference voltage to the output port of the unit-level controller to maintain the direct current bus voltage;
and the fifth grid-connected control unit is used for controlling the load unit to perform load reduction operation according to the load priority when the direct-current bus voltage is in the 5 th operation interval so as to restore the bus voltage to a normal operation interval.
Furthermore, the off-grid control module comprises a first off-grid control unit, a second off-grid control unit, a third off-grid control unit, a fourth off-grid control unit and a fifth off-grid control unit;
the first off-grid control unit is used for taking a port of the energy storage unit as a relaxation node when the direct current bus voltage is in the 1 st running interval and the capacity of the energy storage unit is in a normal state, controlling the direct current bus voltage by adopting a droop control method and controlling the power generation unit to be in an MPPT running mode; otherwise, the port of the power generation unit is used as a relaxation node to maintain the voltage of the direct current bus, and the energy storage unit is in a non-working or charging and discharging recovery stage;
the second off-grid control unit and the third off-grid control unit are respectively used for taking a port of the energy storage unit as a loose node when the direct-current bus voltage is in the 2 nd operation interval or the 3 rd operation interval, maintaining the direct-current bus voltage by adopting a droop control method, and controlling the power generation unit to be in an MPPT operation mode;
the fourth off-grid control unit is used for controlling the power generation unit to exit the MPPT working mode and enter a constant voltage running state when the direct current bus voltage is in the 4 th running interval, instructing a reference voltage to an output port of the unit-level controller and maintaining the direct current bus voltage;
and the fifth off-grid control unit is used for controlling the load unit to perform load reduction operation according to the load priority when the direct-current bus voltage is in the 5 th operation interval so as to restore the bus voltage to a normal operation interval.
Further, the preset optimization target comprises the realization of lowest operation electric charge of the building group direct-current power distribution system and the realization of load constant power control, and the centralized controller comprises an electric charge control module and a power control module;
the electric charge control module comprises a function construction unit and an electric charge minimum optimization unit;
the function construction unit is used for constructing an optimized objective function and constraint conditions for the lowest operation electric charge of the building group direct-current power distribution system;
the lowest electricity charge optimization unit is used for solving the lowest operation electricity charge optimization objective function by adopting a discrete binary particle swarm optimization algorithm to obtain working state instructions of load units in the building group direct-current power distribution system, and outputting the working state instructions to the unit-level controllers corresponding to the load units to realize the lowest operation electricity charge optimization control of the system.
The operation electric charge minimum optimization objective function and the constraint conditions are as follows:
the optimization objective function is:
minf1＝Cbuy-Csell
Figure BDA0002500953350000231
Figure BDA0002500953350000232
wherein,
Figure BDA0002500953350000233
the difference between the total system load power and the system generating power at the moment t;
Figure BDA0002500953350000234
buying electricity price to the power grid for the building group;
Figure BDA0002500953350000235
generating and surfing price for photovoltaic power generation units in a building group direct current power distribution system; ppvThe output power sequence of the photovoltaic power generation unit of the system in a set time period; pAThe load is a load which can not be interrupted in a limited time; pBIs an interruptible load; pCIs a non-dispatchable load; cbuyBuying electricity cost for building group DC distribution system; csellSelling electricity earnings for the building group direct current power distribution system;
the constraint conditions are as follows:
and power balance constraint:
Figure BDA0002500953350000241
wherein,
Figure BDA0002500953350000242
outputting power for a grid-connected unit of the system at the time t;
Figure BDA0002500953350000243
outputting power for the photovoltaic power generation unit of the system at the moment t;
Figure BDA0002500953350000244
outputting power for the system energy storage unit at the moment t;
Figure BDA0002500953350000245
the load power can not be interrupted for the time limit of t;
Figure BDA0002500953350000246
interruptible load power for time t;
Figure BDA0002500953350000247
is time tNon-dispatchable load power;
and (3) constraint of the electric quantity state of the storage battery pack:
SSOCmin≤SSOC(t)≤SSOCmax
wherein S isSOCminThe minimum value of the state of charge of the storage battery pack; sSOCmaxThe maximum value of the state of charge of the storage battery pack; sSOC(t) is the state of charge of the battery pack at time t;
and (3) transmission power constraint of each component unit of the system:
Figure BDA0002500953350000248
wherein, Pi tThe transmission power of each component unit of the building group direct current power distribution system at the time t is represented;
Figure BDA0002500953350000249
the transmission power lower limit value of the ith component unit of the direct current power distribution system of the current building group is obtained;
Figure BDA00025009533500002410
and the transmission power upper limit value of the ith component unit of the direct current power distribution system of the current building group is obtained.
Wherein, the speed updating formula of the discrete binary particle swarm optimization algorithm is as follows:
Figure BDA00025009533500002411
wherein,
Figure BDA00025009533500002412
is the velocity of particle i in the kth iteration;
Figure BDA00025009533500002413
is the position of particle i in the kth iteration; omegakIs the inertial weight; r is a random number between (0, 1);
Figure BDA00025009533500002414
the historical optimal extreme value of the particle i in the k iteration is obtained;
Figure BDA00025009533500002415
the optimal extremum of the population of all the particles in the kth iteration is obtained; c. C1、c2Is a learning factor;
the probability that the velocity value is mapped to [0,1] by using the modified sigmoid function as a mapping function represents the chance that the position state of the particle changes:
Figure BDA00025009533500002416
Figure BDA0002500953350000251
wherein,
Figure BDA0002500953350000252
the change threshold of the particle position state in the k +1 th iteration is set;
Figure BDA0002500953350000253
the particle position state at the (k + 1) th iteration.
Further, the power control module is configured to receive a control instruction sent by the power system, sample output power of each constituent unit of the system, and control the unit-level controller corresponding to the load unit according to the following relationship, so as to implement load constant power control of the system:
Pes＝PL-Ppv-PG
PG＝C
wherein, PesOutputting power for the system energy storage unit; ppvOutputting power for the system photovoltaic power generation unit; pGOutputting power for a system grid-connected unit; c, establishing a constant power reference value; pLLoad total power of building group DC distribution system。
The scheme is formed and realized by the unit-level controller, the local controller and the integrated controller, long-term stability and economic optimality of operation of the building group direct-current power distribution system are guaranteed, the hierarchy is clear, the method is clear, and the system has the capabilities of being applied to various scenes and receiving higher-level scheduling and energy management.
As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims (18)

1. A distributed coordination control method for a building group direct current distribution system is characterized in that each component unit of the building group direct current distribution system is connected with a direct current bus, and the distributed coordination control method comprises the following steps:
the local controller controls the operation modes of the unit-level controllers corresponding to the constituent units according to a preset rule based on the interval of the direct-current bus voltage, wherein the local controller is pre-built in each constituent unit, and the unit-level controllers at least have three operation modes of constant-voltage control, constant-current control and constant-power control;
the centralized controller calculates an optimization result of a preset optimization target, and controls the preset optimization target of the corresponding component unit to reach the optimization result based on the optimization result of the preset optimization target;
the preset optimization objective comprises that the lowest operation electric charge of the building group direct current power distribution system is realized, and the lowest operation electric charge optimization objective function is as follows:
minf1＝Cbuy-Csell
Figure FDA0003033763220000011
Figure FDA0003033763220000012
wherein,
Figure FDA0003033763220000013
the difference between the total system load power and the system generating power at the moment t;
Figure FDA0003033763220000014
buying electricity price to the power grid for the building group;
Figure FDA0003033763220000015
generating and surfing price for photovoltaic power generation units in a building group direct current power distribution system; ppvThe output power sequence of the photovoltaic power generation unit of the system in a set time period; pAThe load is a load which can not be interrupted in a limited time; pBIs an interruptible load; pCIs a non-dispatchable load; cbuyBuying electricity cost for building group DC distribution system; csellSelling electricity earnings for the building group direct current power distribution system;
the constraint conditions of the operation electric charge minimum optimization objective function are as follows:
and power balance constraint:
Figure FDA0003033763220000016
wherein,
Figure FDA0003033763220000017
outputting power for a grid-connected unit of the system at the time t;
Figure FDA0003033763220000018
outputting power for the photovoltaic power generation unit of the system at the moment t;
Figure FDA0003033763220000019
outputting power for the system energy storage unit at the moment t;
Figure FDA00030337632200000110
the load power can not be interrupted for the time limit of t;
Figure FDA00030337632200000111
interruptible load power for time t;
Figure FDA00030337632200000112
load power can not be scheduled at time t;
and (3) constraint of the electric quantity state of the storage battery pack:
SSOCmin≤SSOC(t)≤SSOCmax
wherein S isSOCminThe minimum value of the state of charge of the storage battery pack; sSOCmaxThe maximum value of the state of charge of the storage battery pack; sSOC(t) is the state of charge of the battery pack at time t;
and (3) transmission power constraint of each component unit of the system:
Figure FDA0003033763220000021
wherein, Pi tThe transmission power of each component unit of the building group direct current power distribution system at the time t is represented;
Figure FDA0003033763220000022
the transmission power lower limit value of the ith component unit of the direct current power distribution system of the current building group is obtained;
Figure FDA0003033763220000023
and the transmission power upper limit value of the ith component unit of the direct current power distribution system of the current building group is obtained.
2. The distributed coordination control method for building group dc power distribution system according to claim 1, wherein the dc bus voltage is in a range comprising 5 operating ranges: the voltage condition of the direct current bus in the 1 st operation interval is UL1<Udc<UH1The DC bus voltage condition of the 2 nd operation interval is UH1<Udc<UH2And the voltage condition of the direct current bus in the 3 rd running interval is UL2<Udc<UL1And the DC bus voltage condition in the 4 th operation interval is Udc>UH2And the voltage condition of the direct current bus in the 5 th running interval is Udc<UL2(ii) a Wherein, UdcIs a DC bus voltage, UL2、UL1、UH1、UH2Respectively, voltage stratification thresholds.
3. The distributed coordination control method for the building group direct-current power distribution system according to claim 2, wherein in the grid-connected operation mode, the local controller controls the operation mode of the unit-level controller corresponding to each component unit according to a preset rule based on a section where the direct-current bus voltage is located, and the method includes:
when the direct current bus voltage is in the 1 st operation interval, taking a port of a grid-connected unit as a loose node, controlling the direct current bus voltage by adopting a droop control method, controlling a power generation unit to be in an MPPT operation mode, and controlling an energy storage unit to be in a non-operation or charge-discharge recovery stage;
when the direct current bus voltage is in the 2 nd operation interval or the 3 rd operation interval, the energy storage unit controls the current power and the voltage variation of the grid-connected unit port to meet the preset droop control relation by adopting a droop control method, and compensates the system deviation power, so that the grid-connected unit port outputs constant limit power; controlling the power generation unit to be in an MPPT operation mode;
when the direct current bus voltage is in the 4 th running interval, controlling a power generation unit to exit an MPPT (maximum power point tracking) working mode, entering a constant voltage running state, instructing a reference voltage to an output port of the unit-level controller, and maintaining the direct current bus voltage;
and when the direct current bus voltage is in the 5 th running interval, controlling the load unit to perform load reduction operation according to the load priority, so that the bus voltage is recovered to the normal running interval.
4. The distributed coordination control method for the building complex direct current distribution system according to claim 2, wherein in the off-grid operation mode, the local controller controls the operation mode of the unit-level controller corresponding to each component unit according to a preset rule based on the section of the direct current bus voltage, and the method comprises:
when the direct current bus voltage is in the 1 st running interval and the capacity of the energy storage unit is in a normal state, taking an energy storage unit port as a relaxation node, controlling the direct current bus voltage by adopting a droop control method, and controlling the power generation unit to be in an MPPT running mode; otherwise, the port of the power generation unit is used as a relaxation node to maintain the voltage of the direct current bus, and the energy storage unit is in a non-working or charging and discharging recovery stage;
when the direct current bus voltage is in the 2 nd operation interval or the 3 rd operation interval, taking an energy storage unit port as a relaxation node, maintaining the direct current bus voltage by adopting a droop control method, and controlling a power generation unit to be in an MPPT operation mode;
when the direct current bus voltage is in the 4 th running interval, controlling a power generation unit to exit an MPPT (maximum power point tracking) working mode, entering a constant voltage running state, instructing a reference voltage to an output port of the unit-level controller, and maintaining the direct current bus voltage;
and when the direct current bus voltage is in the 5 th running interval, controlling the load unit to perform load reduction operation according to the load priority, so that the bus voltage is recovered to the normal running interval.
5. The distributed coordination control method for building group direct current distribution system as claimed in claim 3 or 4, characterized in that said droop control method determines equivalent output impedance of system response unit converter by adjusting droop coefficient to realize output current adjustment and power distribution;
the droop characteristic of the direct current voltage of each component unit port of the building group direct current power distribution system is represented as follows:
Figure FDA0003033763220000041
wherein, UdcOutputting a command reference voltage for the local controller,
Figure FDA0003033763220000042
is a reference voltage reference value, IdcAnd outputting direct current voltage for the composition unit, wherein k is a droop coefficient.
6. The method of claim 1, wherein the predetermined optimization objectives comprise minimizing operating power costs and achieving constant power control of the building complex dc power distribution system.
7. The distributed coordination control method for building group dc power distribution system as claimed in claim 6, wherein when said preset optimization objective is to achieve lowest operating power cost of said building group dc power distribution system, said centralized controller calculates an optimization result of the preset optimization objective, and based on the optimization result of the preset optimization objective, controls the preset optimization objective of the corresponding component unit to achieve the optimization result, comprising:
constructing an optimized objective function and constraint conditions for the lowest operation electric charge of the building group direct-current power distribution system;
and solving the minimum optimization objective function of the running electric charge by adopting a discrete binary particle swarm optimization algorithm to obtain working state instructions of the load units in the building swarm direct-current power distribution system, and outputting the working state instructions to the unit-level controllers corresponding to the load units to realize the minimum optimization control of the running electric charge of the system.
8. The distributed coordination control method for building group dc power distribution system according to claim 7, wherein the speed update formula of the discrete binary particle swarm optimization algorithm is:
Figure FDA0003033763220000043
wherein,
Figure FDA0003033763220000044
is the velocity of particle i in the kth iteration;
Figure FDA0003033763220000045
is the position of particle i in the kth iteration; omegakIs the inertial weight; r is a random number between (0, 1);
Figure FDA0003033763220000046
the historical optimal extreme value of the particle i in the k iteration is obtained;
Figure FDA0003033763220000047
the optimal extremum of the population of all the particles in the kth iteration is obtained; c. C1、c2Is a learning factor;
the probability that the velocity value is mapped to [0,1] by using the modified sigmoid function as a mapping function represents the chance that the position state of the particle changes:
Figure FDA0003033763220000051
Figure FDA0003033763220000052
wherein,
Figure FDA0003033763220000053
the change threshold of the particle position state in the k +1 th iteration is set;
Figure FDA0003033763220000054
the particle position state at the (k + 1) th iteration.
9. The distributed coordination control method for a building complex dc power distribution system of claim 8, wherein the inertial weights are updated at each new iteration cycle according to the following equation:
Figure FDA0003033763220000055
wherein, ω ismaxIs the maximum inertial weight; omegaminIs the minimum inertial weight; k is a preset iteration number; k is the current iteration number.
10. The distributed coordination control method for building group dc power distribution system according to claim 6, wherein when the preset optimization objective is to realize load constant power control, the centralized controller calculates an optimization result of the preset optimization objective, and controls the preset optimization objectives of the corresponding constituent units to reach the optimization result based on the optimization result of the preset optimization objective, including:
the centralized controller receives a control instruction sent by the power system, samples the output power of each component unit of the system, and controls the unit-level controllers corresponding to the load units according to the following relation to realize the load constant power control of the system:
Pes＝PL-Ppv-PG
PG＝C
wherein, PesOutputting power for the system energy storage unit; ppvOutputting power for the system photovoltaic power generation unit; pGOutputting power for a system grid-connected unit; c, establishing a constant power reference value; pLThe total load power of the building group direct current power distribution system is obtained.
11. A distributed coordination control system of a building group direct current power distribution system is characterized by comprising a centralized controller, unit-level controllers corresponding to all constituent units of the building group direct current power distribution system and local controllers arranged in all constituent units, wherein all constituent units of the building group direct current power distribution system are connected with a direct current bus; the unit-level controllers corresponding to the constituent units receive control instructions output by the local controller to control the corresponding physical quantity reference values given by the response of the direct-current bus port physical quantity tracking control instructions of the corresponding constituent units, so that the constant-voltage, constant-current and constant-power control of the ports of the constituent units is realized; the unit-level controllers corresponding to the constituent units receive the target optimization instructions output by the collection controller so as to control the preset optimization targets of the corresponding constituent units to achieve the optimization results;
the preset optimization objective comprises the realization of the lowest operation electric charge of the building group direct current power distribution system, and the lowest operation electric charge optimization objective function is as follows:
minf1＝Cbuy-Csell
Figure FDA0003033763220000061
Figure FDA0003033763220000062
wherein,
Figure FDA0003033763220000063
the difference between the total system load power and the system generating power at the moment t;
Figure FDA0003033763220000064
buying electricity price to the power grid for the building group;
Figure FDA0003033763220000065
generating and surfing price for photovoltaic power generation units in a building group direct current power distribution system; ppvThe output power sequence of the photovoltaic power generation unit of the system in a set time period; pAThe load is a load which can not be interrupted in a limited time; pBIs an interruptible load; pCIs a non-dispatchable load; cbuyDirect current distribution for building groupsThe electricity system buys electricity fee; csellSelling electricity earnings for the building group direct current power distribution system;
the constraint conditions of the operation electric charge minimum optimization objective function are as follows:
and power balance constraint:
Figure FDA0003033763220000066
wherein,
Figure FDA0003033763220000067
outputting power for a grid-connected unit of the system at the time t;
Figure FDA0003033763220000068
outputting power for the photovoltaic power generation unit of the system at the moment t;
Figure FDA0003033763220000069
outputting power for the system energy storage unit at the moment t;
Figure FDA00030337632200000610
the load power can not be interrupted for the time limit of t;
Figure FDA00030337632200000611
interruptible load power for time t;
Figure FDA00030337632200000612
load power can not be scheduled at time t;
and (3) constraint of the electric quantity state of the storage battery pack:
SSOCmin≤SSOC(t)≤SSOCmax
wherein S isSOCminThe minimum value of the state of charge of the storage battery pack; sSOCmaxThe maximum value of the state of charge of the storage battery pack; sSOC(t) is the state of charge of the battery pack at time t;
and (3) transmission power constraint of each component unit of the system:
Figure FDA0003033763220000071
wherein, Pi tThe transmission power of each component unit of the building group direct current power distribution system at the time t is represented;
Figure FDA0003033763220000072
the transmission power lower limit value of the ith component unit of the direct current power distribution system of the current building group is obtained;
Figure FDA0003033763220000073
and the transmission power upper limit value of the ith component unit of the direct current power distribution system of the current building group is obtained.
12. The distributed coordination control system for building complex dc power distribution system of claim 11, wherein said dc bus voltage ranges comprise 5 operating ranges: the voltage condition of the direct current bus in the 1 st operation interval is UL1<Udc<UH1The DC bus voltage condition of the 2 nd operation interval is UH1<Udc<UH2And the voltage condition of the direct current bus in the 3 rd running interval is UL2<Udc<UL1And the DC bus voltage condition in the 4 th operation interval is Udc>UH2And the voltage condition of the direct current bus in the 5 th running interval is Udc<UL2(ii) a Wherein, UdcIs a DC bus voltage, UL2、UL1、UH1、UH2Respectively, voltage stratification thresholds.
13. The distributed coordination control system for a building complex dc distribution system of claim 12, wherein said local controller comprises a grid-connected control module and an off-grid control module, wherein:
the grid-connected control module is used for adjusting the operation mode of the corresponding unit-level controller according to the interval of the direct-current bus voltage in the grid-connected operation mode;
and the off-grid control module is used for adjusting the operation mode of the corresponding unit-level controller according to the interval of the DC bus voltage in the off-grid operation mode.
14. The distributed coordination control system for building complex dc power distribution system of claim 13, wherein said grid-connected control module comprises a first grid-connected control unit, a second grid-connected control unit, a third grid-connected control unit, a fourth grid-connected control unit, and a fifth grid-connected control unit;
the first grid-connected control unit is used for controlling the direct-current bus voltage by using a droop control method by taking a grid-connected unit port as a loose node when the direct-current bus voltage is in the 1 st operation interval and controlling the power generation unit to be in an MPPT operation mode, and the energy storage unit is in a non-operation or charge-discharge recovery stage
The second grid-connected control unit and the third grid-connected control unit are respectively used for controlling the circulating power and the voltage variation of a grid-connected unit port to meet a preset droop control relation by the energy storage unit by adopting a droop control method when the direct-current bus voltage is in the 2 nd operating interval or the 3 rd operating interval, compensating the system deviation power, enabling the grid-connected unit port to output constant limit power and controlling the power generation unit to be in an MPPT operating mode;
the fourth grid-connected control unit is used for controlling the power generation unit to exit the MPPT working mode and enter a constant voltage running state when the direct current bus voltage is in the 4 th running interval, and instructing a reference voltage to the output port of the unit-level controller to maintain the direct current bus voltage;
and the fifth grid-connected control unit is used for controlling the load unit to perform load reduction operation according to the load priority when the direct-current bus voltage is in the 5 th operation interval so as to restore the bus voltage to a normal operation interval.
15. The distributed coordination control system for building complex dc power distribution systems of claim 13, wherein said off-grid control module comprises a first off-grid control unit, a second off-grid control unit, a third off-grid control unit, a fourth off-grid control unit, and a fifth off-grid control unit;
the first off-grid control unit is used for taking a port of the energy storage unit as a relaxation node when the direct current bus voltage is in the 1 st running interval and the capacity of the energy storage unit is in a normal state, controlling the direct current bus voltage by adopting a droop control method and controlling the power generation unit to be in an MPPT running mode; otherwise, the port of the power generation unit is used as a relaxation node to maintain the voltage of the direct current bus, and the energy storage unit is in a non-working or charging and discharging recovery stage;
the second off-grid control unit and the third off-grid control unit are respectively used for taking a port of the energy storage unit as a loose node when the direct-current bus voltage is in the 2 nd operation interval or the 3 rd operation interval, maintaining the direct-current bus voltage by adopting a droop control method, and controlling the power generation unit to be in an MPPT operation mode;
the fourth off-grid control unit is used for controlling the power generation unit to exit the MPPT working mode and enter a constant voltage running state when the direct current bus voltage is in the 4 th running interval, instructing a reference voltage to an output port of the unit-level controller and maintaining the direct current bus voltage;
and the fifth off-grid control unit is used for controlling the load unit to perform load reduction operation according to the load priority when the direct-current bus voltage is in the 5 th operation interval so as to restore the bus voltage to a normal operation interval.
16. The system as claimed in claim 11, wherein the preset optimization objectives include minimizing the operating power rate of the building complex dc power distribution system and implementing constant load power control, and the centralized controller includes a power rate control module and a power control module;
the electric charge control module comprises a function construction unit and an electric charge minimum optimization unit;
the function construction unit is used for constructing an optimized objective function and constraint conditions for the lowest operation electric charge of the building group direct-current power distribution system;
the lowest electricity charge optimization unit is used for solving the lowest operation electricity charge optimization objective function by adopting a discrete binary particle swarm optimization algorithm to obtain working state instructions of load units in the building group direct-current power distribution system, and outputting the working state instructions to the unit-level controllers corresponding to the load units to realize the lowest operation electricity charge optimization control of the system.
17. The distributed coordination control system for building complex dc power distribution system of claim 16, wherein said discrete binary particle swarm optimization algorithm has a speed update formula of:
Figure FDA0003033763220000091
wherein,
Figure FDA0003033763220000092
is the velocity of particle i in the kth iteration;
Figure FDA0003033763220000093
is the position of particle i in the kth iteration; omegakIs the inertial weight; r is a random number between (0, 1);
Figure FDA0003033763220000094
the historical optimal extreme value of the particle i in the k iteration is obtained;
Figure FDA0003033763220000095
the optimal extremum of the population of all the particles in the kth iteration is obtained; c. C1、c2Is a learning factor;
the probability that the velocity value is mapped to [0,1] by using the modified sigmoid function as a mapping function represents the chance that the position state of the particle changes:
Figure FDA0003033763220000101
Figure FDA0003033763220000102
wherein,
Figure FDA0003033763220000103
the change threshold of the particle position state in the k +1 th iteration is set;
Figure FDA0003033763220000104
the particle position state at the (k + 1) th iteration.
18. The distributed coordination control system for building complex dc power distribution system of claim 16, wherein the power control module is configured to receive a control command from the power system, sample the output power of each component unit of the system, and control the unit-level controller of the corresponding load unit according to the following relationship to realize the load constant power control of the system:
Pes＝PL-Ppv-PG
PG＝C
wherein, PesOutputting power for the system energy storage unit; ppvOutputting power for the system photovoltaic power generation unit; pGOutputting power for a system grid-connected unit; c, establishing a constant power reference value; pLThe total load power of the building group direct current power distribution system is obtained.
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CN112271716A (en) * 2020-10-22 2021-01-26 珠海格力电器股份有限公司 Power supply system for improving starting stability, control method thereof and air conditioning unit
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CN117060422B (en) * 2023-10-11 2024-01-19 江苏省电力试验研究院有限公司 Light storage direct-flexible building control method, system, computer equipment and storage medium

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105226632A (en) * 2015-10-30 2016-01-06 上海电力学院 A kind of multi-mode of DC micro power grid system switches control method for coordinating
CN108471109A (en) * 2018-04-24 2018-08-31 清华大学 The univesral distribution formula control method and system of the more micro-grid systems of direct current
CN108667147A (en) * 2018-06-15 2018-10-16 贵州电网有限责任公司 Straightening stream distribution center Optimization Scheduling in a kind of flexibility containing more micro-capacitance sensors
CN110212517A (en) * 2019-06-24 2019-09-06 东南大学 The distributing unified control method of mesolow direct-flow distribution system

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPWO2003075427A1 (en) * 2002-03-06 2005-06-30 松下電器産業株式会社 Decentralized energy supply system setting device
US8639392B2 (en) * 2008-09-29 2014-01-28 Battelle Memorial Institute Electric power grid control using a market-based resource allocation system
US9836803B2 (en) * 2010-06-25 2017-12-05 Lg Electronics Inc Network system
KR101748766B1 (en) * 2010-12-23 2017-07-03 한국전자통신연구원 Method and system for providing energy management in smart grid environment, energy provider in smart grid environment
US10169832B2 (en) * 2013-05-08 2019-01-01 Instant Access Networks, Llc Method and instrumentation for sustainable energy load flow management system performing as resilient adaptive microgrid system
EP2858015A1 (en) * 2013-10-04 2015-04-08 Building Research Establishment Ltd System and method for simulation, control and performance monitoring of energy systems

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105226632A (en) * 2015-10-30 2016-01-06 上海电力学院 A kind of multi-mode of DC micro power grid system switches control method for coordinating
CN108471109A (en) * 2018-04-24 2018-08-31 清华大学 The univesral distribution formula control method and system of the more micro-grid systems of direct current
CN108667147A (en) * 2018-06-15 2018-10-16 贵州电网有限责任公司 Straightening stream distribution center Optimization Scheduling in a kind of flexibility containing more micro-capacitance sensors
CN110212517A (en) * 2019-06-24 2019-09-06 东南大学 The distributing unified control method of mesolow direct-flow distribution system

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
多电压源型微源组网的微电网运行控制与能量管理策略研究;鲍薇;《中国博士学位论文全文数据库 工程科技II辑》;20141115;第2章-第4章 *

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