CN111277003A - Micro-grid power distribution system - Google Patents

Micro-grid power distribution system Download PDF

Info

Publication number
CN111277003A
CN111277003A CN202010239105.8A CN202010239105A CN111277003A CN 111277003 A CN111277003 A CN 111277003A CN 202010239105 A CN202010239105 A CN 202010239105A CN 111277003 A CN111277003 A CN 111277003A
Authority
CN
China
Prior art keywords
grid
micro
power supply
transformer
power distribution
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202010239105.8A
Other languages
Chinese (zh)
Inventor
宋文武
简余明
杨胜辉
熊雁澜
曾潞
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Guizhou Changzheng Transmission And Distribution Electric Co Ltd
Original Assignee
Guizhou Changzheng Transmission And Distribution Electric Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Guizhou Changzheng Transmission And Distribution Electric Co Ltd filed Critical Guizhou Changzheng Transmission And Distribution Electric Co Ltd
Priority to CN202010239105.8A priority Critical patent/CN111277003A/en
Publication of CN111277003A publication Critical patent/CN111277003A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/01—Arrangements for reducing harmonics or ripples
    • 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
    • H02J3/18—Arrangements for adjusting, eliminating or compensating reactive power in networks
    • 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
    • H02J3/26—Arrangements for eliminating or reducing asymmetry in polyphase networks
    • 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
    • H02J3/30—Arrangements for balancing of the load in a network by storage of energy using dynamo-electric machines coupled to flywheels
    • 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
    • H02J3/46—Controlling of the sharing of output between the generators, converters, or transformers
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
    • Y02E40/30—Reactive power compensation
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
    • Y02E40/40—Arrangements for reducing harmonics
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
    • Y02E40/50—Arrangements for eliminating or reducing asymmetry in polyphase networks
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/16—Mechanical energy storage, e.g. flywheels or pressurised fluids

Abstract

The application discloses a micro-grid power distribution system which comprises a main power distribution network, a main transformer, a micro-grid and an energy storage power supply, wherein the main transformer is used for merging the micro-grid into the main power distribution network; the micro-grid comprises a micro-grid main line, a public connection point, a load transformer, a controller, an isolation transformer, a coupling inductor, a multifunctional grid-connected inverter and a distributed power supply, wherein the load is connected to the micro-grid main line through the load transformer, the distributed power supply is connected to the micro-grid main line through the multifunctional grid-connected inverter and the coupling inductor and the isolation transformer, the controller is electrically connected with the inverter and connected to the micro-grid, and the controller is used for switching the working state of the multifunctional grid-connected inverter according to the power generation state of the distributed power supply. The multifunctional grid-connected inverter can simultaneously transmit the energy of the distributed power supply to the micro-grid, and can improve the electric energy quality of a public access point of the micro-grid connected to the power distribution network.

Description

Micro-grid power distribution system
Technical Field
The invention belongs to the technical field of power transmission and distribution, and particularly relates to a micro-grid power distribution system.
Background
With the demand for electric energy becoming greater and greater, countries have developed relevant policies that encourage the development of Distributed Generation (DG) for renewable energy sources such as photovoltaic, wind, fuel cells, etc. Unlike conventional centralized power generation, distributed power generation is a mode of generating power to users using small power generation units dispersed in the vicinity of the users. However, distributed power generation has its limitations. For example, when a power system fails, the distributed energy resource must be immediately taken out of service. In order to exploit as much as possible the economic benefits of distributed generation and improve reliability, micro-grids are being used. A microgrid is an integrated system consisting of a load and a plurality of distributed power sources. The current generated by a plurality of distributed voltages flows to the bus of the microgrid and flows to each user needing electricity in a small area from the bus of the microgrid.
However, due to the inherent characteristics of wind energy, solar energy and the like, such as intermittency and randomness, unlike synchronous generators, the access of a power grid to a DG usually imposes limitation and isolation requirements. At present, the micro-grid technology has existed as a main way to solve the DG networking. However, the large number of power electronics contained in the microgrid, coupled with the non-linearity, imbalance and reactive nature of the microgrid local loads, can degrade the quality of the electrical energy at the microgrid Point of Common Connection (PCC). At present, the pricing of electric energy according to the quality becomes the development trend of the electric power market, the quality of the electric energy at the PCC point of the micro-grid is good and bad, and the economic benefit of the micro-grid is directly related.
Disclosure of Invention
The invention aims to provide a micro-grid power distribution system to solve the problem that the quality of electric energy at a PCC (point of charge coupled device) of a micro-grid in the prior art is low.
The micro-grid power distribution system comprises a main power distribution network, a main transformer, a micro-grid and an energy storage power supply, wherein the main transformer is used for merging the micro-grid into the main power distribution network; the micro-grid comprises a micro-grid main line, a public connection point, a load transformer, a controller, an isolation transformer, a coupling inductor, a multifunctional grid-connected inverter and a distributed power supply, wherein the load is connected to the micro-grid main line through the load transformer, the distributed power supply is connected to the micro-grid main line through the multifunctional grid-connected inverter and the coupling inductor and the isolation transformer, the controller is electrically connected with the multifunctional grid-connected inverter and connected to the micro-grid, and the controller is used for switching the working state of the multifunctional grid-connected inverter according to the power generation state of the distributed power supply.
Further, the load includes a linear load and a nonlinear load.
Further, the multifunctional grid-connected inverter is controlled by adopting a pulse width modulation current source.
Further, the distributed power supply comprises a wind turbine generator, a photovoltaic cell, a flywheel energy storage or a water pumping energy storage power station.
The beneficial effect of this scheme does: 1. the multifunctional grid-connected inverter can simultaneously transmit the energy of the distributed power supply to the microgrid, can improve the electric energy quality of a public access point of the microgrid connected to the power distribution network, and achieves the functions of harmonic current compensation, reactive compensation, three-phase unbalance compensation and the like.
2. The controller switches the working state of the multifunctional grid-connected inverter according to the change of the power generation state of the distributed power supply, and the method specifically comprises the following steps: DG output PDGLoad total required power P with microgridLThe relation between MFGCI (multifunctional grid-connected inverter with the function of a conventional inverter and the function of an active filter APF) working states is divided into 3 types, and then 3 different control strategies are corresponded, 1) PDG0. Corresponding photovoltaic array cannot output power at nightAt this time, the MFGCI only performs APF operation, and the dc side energy is provided by the energy storage power supply. 2)0<PDG<PLThat is, when the DG power generation state is insufficient, the MFGCI at this time guarantees the APF function, PDGThe remaining power powers the load through a load transformer. Deficient part PL-PDGThe energy is supplied by an energy storage power supply. 3) PDG>PLWhen the DG is in the power generation state, the device stores the redundant energy into the energy storage power supply while completing the APF and supplying power to the load. Through the control strategy, the multifunctional grid-connected inverter is realized, and meanwhile, the requirement on constant direct-current side voltage is lowered under the condition that the distributed power supply is insufficient in power generation, so that the utilization benefit of the inverter is greatly improved.
Drawings
Fig. 1 is a block diagram of a microgrid power distribution system according to the present invention.
Detailed Description
The following is further detailed by way of specific embodiments:
the embodiment is basically as shown in the attached figure 1: a micro-grid power distribution system comprises a main power distribution network, a main transformer, a micro-grid and an energy storage power supply, wherein the main transformer is used for merging the micro-grid into the main power distribution network; the microgrid comprises a microgrid main line, a public connection point, a linear load, a nonlinear load, a load transformer, a controller, an isolation transformer, a coupling inductor, a multifunctional grid-connected inverter and a distributed power supply, wherein the load is connected to the microgrid main line through the load transformer, the distributed power supply is connected to the microgrid main line through the coupling inductor and the isolation transformer and is controlled by a pulse width modulation current source, the controller is electrically connected with the inverter and is connected to the microgrid, the controller is used for switching the working state of the multifunctional grid-connected inverter according to the power generation state of the distributed power supply, and the distributed power supply comprises a wind turbine generator, a photovoltaic battery, a flywheel energy storage station or a water pumping energy storage power station.
The specific implementation process is as follows: the controller switches the working state of the multifunctional grid-connected inverter according to the change of the power generation state of the distributed power supply, specifically to: DG output PDGLoad total required power P with microgridLThe relation between MFGCI working states is divided into 3 kinds, and then 3 different control strategies are corresponded, 1) PDG0. Corresponding to the state that the photovoltaic array cannot output power at night, the MFGCI only performs APF operation at the moment, and the energy at the direct current side of the MFGCI is provided by the energy storage power supply. 2)0<PDG<PLThat is, when the DG power generation state is insufficient, the MFGCI at this time guarantees the APF function, PDGThe remaining power powers the load through a load transformer. Deficient part PL-PDGThe energy is supplied by an energy storage power supply. 3) PDG>PLWhen the DG is in the power generation state, the device stores the redundant energy into the energy storage power supply while completing the APF and supplying power to the load.
The above are merely examples of the present invention, and common general knowledge of known specific structures and characteristics in the schemes is not described herein. It should be noted that, for those skilled in the art, without departing from the structure of the present invention, several changes and modifications can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicability of the patent. The scope of the claims of the present application shall be determined by the contents of the claims, and the description of the embodiments and the like in the specification shall be used to explain the contents of the claims.

Claims (4)

1. A microgrid power distribution system, characterized by: the system comprises a main power distribution network, a main transformer, a microgrid and an energy storage power supply, wherein the main transformer is used for merging the microgrid into the main power distribution network; the micro-grid comprises a micro-grid main line, a public connection point, a load transformer, a controller, an isolation transformer, a coupling inductor, a multifunctional grid-connected inverter and a distributed power supply, wherein the load is connected to the micro-grid main line through the load transformer, the distributed power supply is connected to the micro-grid main line through the multifunctional grid-connected inverter and the coupling inductor and the isolation transformer, the controller is electrically connected with the multifunctional grid-connected inverter and connected to the micro-grid, and the controller is used for switching the working state of the multifunctional grid-connected inverter according to the power generation state of the distributed power supply.
2. The microgrid power distribution system of claim 1, wherein: the load includes a linear load and a non-linear load.
3. The microgrid power distribution system of claim 2, wherein: the multifunctional grid-connected inverter is controlled by adopting a pulse width modulation current source.
4. A microgrid power distribution system according to claim 3, characterized in that: the distributed power supply comprises a wind turbine generator, a photovoltaic cell and a flywheel energy storage or water pumping energy storage power station.
CN202010239105.8A 2020-03-30 2020-03-30 Micro-grid power distribution system Pending CN111277003A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010239105.8A CN111277003A (en) 2020-03-30 2020-03-30 Micro-grid power distribution system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010239105.8A CN111277003A (en) 2020-03-30 2020-03-30 Micro-grid power distribution system

Publications (1)

Publication Number Publication Date
CN111277003A true CN111277003A (en) 2020-06-12

Family

ID=71000880

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010239105.8A Pending CN111277003A (en) 2020-03-30 2020-03-30 Micro-grid power distribution system

Country Status (1)

Country Link
CN (1) CN111277003A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113824151A (en) * 2021-08-16 2021-12-21 青海黄河上游水电开发有限责任公司西宁太阳能电力分公司 Distributed photovoltaic green energy system with energy storage function and operation method thereof

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101931238A (en) * 2010-04-29 2010-12-29 浙江省电力试验研究院 Master-slave strategy-based microgrid system coordination control method
CN102931675A (en) * 2011-08-11 2013-02-13 周锡卫 Structure and method for multi-purpose self-adaptive solar inverter
CN205610235U (en) * 2016-05-10 2016-09-28 天津中德应用技术大学 Novel inverter that adaptation smart power grids required
CN109103925A (en) * 2018-07-31 2018-12-28 国网江苏省电力有限公司淮安供电分公司 A kind of micro-capacitance sensor based on photovoltaic power generation

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101931238A (en) * 2010-04-29 2010-12-29 浙江省电力试验研究院 Master-slave strategy-based microgrid system coordination control method
CN102931675A (en) * 2011-08-11 2013-02-13 周锡卫 Structure and method for multi-purpose self-adaptive solar inverter
CN205610235U (en) * 2016-05-10 2016-09-28 天津中德应用技术大学 Novel inverter that adaptation smart power grids required
CN109103925A (en) * 2018-07-31 2018-12-28 国网江苏省电力有限公司淮安供电分公司 A kind of micro-capacitance sensor based on photovoltaic power generation

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113824151A (en) * 2021-08-16 2021-12-21 青海黄河上游水电开发有限责任公司西宁太阳能电力分公司 Distributed photovoltaic green energy system with energy storage function and operation method thereof

Similar Documents

Publication Publication Date Title
Tamalouzt et al. Performances analysis of WT-DFIG with PV and fuel cell hybrid power sources system associated with hydrogen storage hybrid energy system
Hartono et al. Review of microgrid technology
Wang et al. A hybrid AC/DC micro-grid architecture, operation and control
Ambia et al. Centralized power control strategy for AC-DC hybrid micro-grid system using multi-converter scheme
US20020036430A1 (en) Local area grid for distributed power
CN106786755A (en) A kind of energy-storage system and control method
Vandoorn et al. Reactive power sharing in an islanded microgrid
Zhu et al. Research progress of AC, DC and their hybrid micro-grids
Jamroen et al. A study on SOC management of energy storage system for voltage regulation application in distribution network
CN111277003A (en) Micro-grid power distribution system
CN202513586U (en) Intelligent micro-grid using renewable energy for generating power
CN112421679A (en) Electrical wiring structure based on hybrid micro-grid and energy flowing method thereof
Pozo et al. Battery energy storage system for a hybrid generation system grid connected using fuzzy controllers
Percis et al. Reactive power compensation using fuzzy logic controlled UPFC in a hybrid microgrid
Lopes et al. Application of Battery Energy Storage System in Photovoltaic Power Plants Connected to the Distribution Grid
Ramos-Ruiz et al. Power electronics intelligence at the grid edge-enables energy budgeting
Hwang Application of photovoltaic systems for rural electrification at remote Islands
Malik et al. Hybrid operational approach for PV/DG microgrid without storage device
Nanda et al. Power Quality Analysis by using Active Filter in AC/DC Microgrid
Thangella et al. Optimal design for solar cell and fuel cell renewable source to enhance the power quality in a micro grid system
Yahoui et al. A control strategy for DC Smart Grids operation
Tingji et al. A multiport energy hub for the connection of multi power flow: A simulating case
Pinnarelli et al. Optimal management of energy storage systems integrated in nanogrids for virtual “nonsumer” community
Nanda et al. Management of Power in AC/DC Hybrid Microgrid and its Harmonic Analysis by using D-STATCOM
Omara et al. Voltage Stability Analysis of Grid-Connected Microgrid Incorporating Plug-in Electric Vehicles

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
RJ01 Rejection of invention patent application after publication

Application publication date: 20200612

RJ01 Rejection of invention patent application after publication